c-common.c revision 260011
1/* Subroutines shared by all languages that are variants of C. 2 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 3 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc. 4 5This file is part of GCC. 6 7GCC is free software; you can redistribute it and/or modify it under 8the terms of the GNU General Public License as published by the Free 9Software Foundation; either version 2, or (at your option) any later 10version. 11 12GCC is distributed in the hope that it will be useful, but WITHOUT ANY 13WARRANTY; without even the implied warranty of MERCHANTABILITY or 14FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15for more details. 16 17You should have received a copy of the GNU General Public License 18along with GCC; see the file COPYING. If not, write to the Free 19Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 2002110-1301, USA. */ 21 22#include "config.h" 23#include "system.h" 24#include "coretypes.h" 25#include "tm.h" 26#include "intl.h" 27#include "tree.h" 28#include "flags.h" 29#include "output.h" 30#include "c-pragma.h" 31#include "rtl.h" 32#include "ggc.h" 33#include "varray.h" 34#include "expr.h" 35#include "c-common.h" 36#include "diagnostic.h" 37#include "tm_p.h" 38#include "obstack.h" 39#include "cpplib.h" 40#include "target.h" 41#include "langhooks.h" 42#include "tree-inline.h" 43#include "c-tree.h" 44#include "toplev.h" 45#include "tree-iterator.h" 46#include "hashtab.h" 47#include "tree-mudflap.h" 48#include "opts.h" 49#include "real.h" 50#include "cgraph.h" 51 52cpp_reader *parse_in; /* Declared in c-pragma.h. */ 53 54/* We let tm.h override the types used here, to handle trivial differences 55 such as the choice of unsigned int or long unsigned int for size_t. 56 When machines start needing nontrivial differences in the size type, 57 it would be best to do something here to figure out automatically 58 from other information what type to use. */ 59 60#ifndef SIZE_TYPE 61#define SIZE_TYPE "long unsigned int" 62#endif 63 64#ifndef PID_TYPE 65#define PID_TYPE "int" 66#endif 67 68#ifndef WCHAR_TYPE 69#define WCHAR_TYPE "int" 70#endif 71 72/* WCHAR_TYPE gets overridden by -fshort-wchar. */ 73#define MODIFIED_WCHAR_TYPE \ 74 (flag_short_wchar ? "short unsigned int" : WCHAR_TYPE) 75 76#ifndef PTRDIFF_TYPE 77#define PTRDIFF_TYPE "long int" 78#endif 79 80#ifndef WINT_TYPE 81#define WINT_TYPE "unsigned int" 82#endif 83 84#ifndef INTMAX_TYPE 85#define INTMAX_TYPE ((INT_TYPE_SIZE == LONG_LONG_TYPE_SIZE) \ 86 ? "int" \ 87 : ((LONG_TYPE_SIZE == LONG_LONG_TYPE_SIZE) \ 88 ? "long int" \ 89 : "long long int")) 90#endif 91 92#ifndef UINTMAX_TYPE 93#define UINTMAX_TYPE ((INT_TYPE_SIZE == LONG_LONG_TYPE_SIZE) \ 94 ? "unsigned int" \ 95 : ((LONG_TYPE_SIZE == LONG_LONG_TYPE_SIZE) \ 96 ? "long unsigned int" \ 97 : "long long unsigned int")) 98#endif 99 100/* The following symbols are subsumed in the c_global_trees array, and 101 listed here individually for documentation purposes. 102 103 INTEGER_TYPE and REAL_TYPE nodes for the standard data types. 104 105 tree short_integer_type_node; 106 tree long_integer_type_node; 107 tree long_long_integer_type_node; 108 109 tree short_unsigned_type_node; 110 tree long_unsigned_type_node; 111 tree long_long_unsigned_type_node; 112 113 tree truthvalue_type_node; 114 tree truthvalue_false_node; 115 tree truthvalue_true_node; 116 117 tree ptrdiff_type_node; 118 119 tree unsigned_char_type_node; 120 tree signed_char_type_node; 121 tree wchar_type_node; 122 tree signed_wchar_type_node; 123 tree unsigned_wchar_type_node; 124 125 tree float_type_node; 126 tree double_type_node; 127 tree long_double_type_node; 128 129 tree complex_integer_type_node; 130 tree complex_float_type_node; 131 tree complex_double_type_node; 132 tree complex_long_double_type_node; 133 134 tree dfloat32_type_node; 135 tree dfloat64_type_node; 136 tree_dfloat128_type_node; 137 138 tree intQI_type_node; 139 tree intHI_type_node; 140 tree intSI_type_node; 141 tree intDI_type_node; 142 tree intTI_type_node; 143 144 tree unsigned_intQI_type_node; 145 tree unsigned_intHI_type_node; 146 tree unsigned_intSI_type_node; 147 tree unsigned_intDI_type_node; 148 tree unsigned_intTI_type_node; 149 150 tree widest_integer_literal_type_node; 151 tree widest_unsigned_literal_type_node; 152 153 Nodes for types `void *' and `const void *'. 154 155 tree ptr_type_node, const_ptr_type_node; 156 157 Nodes for types `char *' and `const char *'. 158 159 tree string_type_node, const_string_type_node; 160 161 Type `char[SOMENUMBER]'. 162 Used when an array of char is needed and the size is irrelevant. 163 164 tree char_array_type_node; 165 166 Type `int[SOMENUMBER]' or something like it. 167 Used when an array of int needed and the size is irrelevant. 168 169 tree int_array_type_node; 170 171 Type `wchar_t[SOMENUMBER]' or something like it. 172 Used when a wide string literal is created. 173 174 tree wchar_array_type_node; 175 176 Type `int ()' -- used for implicit declaration of functions. 177 178 tree default_function_type; 179 180 A VOID_TYPE node, packaged in a TREE_LIST. 181 182 tree void_list_node; 183 184 The lazily created VAR_DECLs for __FUNCTION__, __PRETTY_FUNCTION__, 185 and __func__. (C doesn't generate __FUNCTION__ and__PRETTY_FUNCTION__ 186 VAR_DECLS, but C++ does.) 187 188 tree function_name_decl_node; 189 tree pretty_function_name_decl_node; 190 tree c99_function_name_decl_node; 191 192 Stack of nested function name VAR_DECLs. 193 194 tree saved_function_name_decls; 195 196*/ 197 198tree c_global_trees[CTI_MAX]; 199 200/* Switches common to the C front ends. */ 201 202/* Nonzero if prepreprocessing only. */ 203 204int flag_preprocess_only; 205 206/* Nonzero means don't output line number information. */ 207 208char flag_no_line_commands; 209 210/* Nonzero causes -E output not to be done, but directives such as 211 #define that have side effects are still obeyed. */ 212 213char flag_no_output; 214 215/* Nonzero means dump macros in some fashion. */ 216 217char flag_dump_macros; 218 219/* Nonzero means pass #include lines through to the output. */ 220 221char flag_dump_includes; 222 223/* Nonzero means process PCH files while preprocessing. */ 224 225bool flag_pch_preprocess; 226 227/* The file name to which we should write a precompiled header, or 228 NULL if no header will be written in this compile. */ 229 230const char *pch_file; 231 232/* Nonzero if an ISO standard was selected. It rejects macros in the 233 user's namespace. */ 234int flag_iso; 235 236/* Nonzero if -undef was given. It suppresses target built-in macros 237 and assertions. */ 238int flag_undef; 239 240/* Nonzero means don't recognize the non-ANSI builtin functions. */ 241 242int flag_no_builtin; 243 244/* Nonzero means don't recognize the non-ANSI builtin functions. 245 -ansi sets this. */ 246 247int flag_no_nonansi_builtin; 248 249/* Nonzero means give `double' the same size as `float'. */ 250 251int flag_short_double; 252 253/* Nonzero means give `wchar_t' the same size as `short'. */ 254 255int flag_short_wchar; 256 257/* Nonzero means allow Microsoft extensions without warnings or errors. */ 258int flag_ms_extensions; 259 260/* Nonzero means don't recognize the keyword `asm'. */ 261 262int flag_no_asm; 263 264/* Nonzero means to treat bitfields as signed unless they say `unsigned'. */ 265 266int flag_signed_bitfields = 1; 267 268/* Warn about #pragma directives that are not recognized. */ 269 270int warn_unknown_pragmas; /* Tri state variable. */ 271 272/* Warn about format/argument anomalies in calls to formatted I/O functions 273 (*printf, *scanf, strftime, strfmon, etc.). */ 274 275int warn_format; 276 277/* Warn about using __null (as NULL in C++) as sentinel. For code compiled 278 with GCC this doesn't matter as __null is guaranteed to have the right 279 size. */ 280 281int warn_strict_null_sentinel; 282 283/* Zero means that faster, ...NonNil variants of objc_msgSend... 284 calls will be used in ObjC; passing nil receivers to such calls 285 will most likely result in crashes. */ 286int flag_nil_receivers = 1; 287 288/* Nonzero means that code generation will be altered to support 289 "zero-link" execution. This currently affects ObjC only, but may 290 affect other languages in the future. */ 291int flag_zero_link = 0; 292 293/* Nonzero means emit an '__OBJC, __image_info' for the current translation 294 unit. It will inform the ObjC runtime that class definition(s) herein 295 contained are to replace one(s) previously loaded. */ 296int flag_replace_objc_classes = 0; 297 298/* C/ObjC language option variables. */ 299 300 301/* Nonzero means allow type mismatches in conditional expressions; 302 just make their values `void'. */ 303 304int flag_cond_mismatch; 305 306/* Nonzero means enable C89 Amendment 1 features. */ 307 308int flag_isoc94; 309 310/* Nonzero means use the ISO C99 dialect of C. */ 311 312int flag_isoc99; 313 314/* Nonzero means that we have builtin functions, and main is an int. */ 315 316int flag_hosted = 1; 317 318/* Warn if main is suspicious. */ 319 320int warn_main; 321 322 323/* ObjC language option variables. */ 324 325 326/* Open and close the file for outputting class declarations, if 327 requested (ObjC). */ 328 329int flag_gen_declaration; 330 331/* Tells the compiler that this is a special run. Do not perform any 332 compiling, instead we are to test some platform dependent features 333 and output a C header file with appropriate definitions. */ 334 335int print_struct_values; 336 337/* Tells the compiler what is the constant string class for Objc. */ 338 339const char *constant_string_class_name; 340 341 342/* C++ language option variables. */ 343 344 345/* Nonzero means don't recognize any extension keywords. */ 346 347int flag_no_gnu_keywords; 348 349/* Nonzero means do emit exported implementations of functions even if 350 they can be inlined. */ 351 352int flag_implement_inlines = 1; 353 354/* Nonzero means that implicit instantiations will be emitted if needed. */ 355 356int flag_implicit_templates = 1; 357 358/* Nonzero means that implicit instantiations of inline templates will be 359 emitted if needed, even if instantiations of non-inline templates 360 aren't. */ 361 362int flag_implicit_inline_templates = 1; 363 364/* Nonzero means generate separate instantiation control files and 365 juggle them at link time. */ 366 367int flag_use_repository; 368 369/* Nonzero if we want to issue diagnostics that the standard says are not 370 required. */ 371 372int flag_optional_diags = 1; 373 374/* Nonzero means we should attempt to elide constructors when possible. */ 375 376int flag_elide_constructors = 1; 377 378/* Nonzero means that member functions defined in class scope are 379 inline by default. */ 380 381int flag_default_inline = 1; 382 383/* Controls whether compiler generates 'type descriptor' that give 384 run-time type information. */ 385 386int flag_rtti = 1; 387 388/* Nonzero if we want to conserve space in the .o files. We do this 389 by putting uninitialized data and runtime initialized data into 390 .common instead of .data at the expense of not flagging multiple 391 definitions. */ 392 393int flag_conserve_space; 394 395/* Nonzero if we want to obey access control semantics. */ 396 397int flag_access_control = 1; 398 399/* Nonzero if we want to check the return value of new and avoid calling 400 constructors if it is a null pointer. */ 401 402int flag_check_new; 403 404/* Nonzero if we want the new ISO rules for pushing a new scope for `for' 405 initialization variables. 406 0: Old rules, set by -fno-for-scope. 407 2: New ISO rules, set by -ffor-scope. 408 1: Try to implement new ISO rules, but with backup compatibility 409 (and warnings). This is the default, for now. */ 410 411int flag_new_for_scope = 1; 412 413/* Nonzero if we want to emit defined symbols with common-like linkage as 414 weak symbols where possible, in order to conform to C++ semantics. 415 Otherwise, emit them as local symbols. */ 416 417int flag_weak = 1; 418 419/* 0 means we want the preprocessor to not emit line directives for 420 the current working directory. 1 means we want it to do it. -1 421 means we should decide depending on whether debugging information 422 is being emitted or not. */ 423 424int flag_working_directory = -1; 425 426/* Nonzero to use __cxa_atexit, rather than atexit, to register 427 destructors for local statics and global objects. '2' means it has been 428 set nonzero as a default, not by a command-line flag. */ 429 430int flag_use_cxa_atexit = DEFAULT_USE_CXA_ATEXIT; 431 432/* Nonzero to use __cxa_get_exception_ptr in C++ exception-handling 433 code. '2' means it has not been set explicitly on the command line. */ 434 435int flag_use_cxa_get_exception_ptr = 2; 436 437/* Nonzero means make the default pedwarns warnings instead of errors. 438 The value of this flag is ignored if -pedantic is specified. */ 439 440int flag_permissive; 441 442/* Nonzero means to implement standard semantics for exception 443 specifications, calling unexpected if an exception is thrown that 444 doesn't match the specification. Zero means to treat them as 445 assertions and optimize accordingly, but not check them. */ 446 447int flag_enforce_eh_specs = 1; 448 449/* Nonzero means to generate thread-safe code for initializing local 450 statics. */ 451 452int flag_threadsafe_statics = 1; 453 454/* Nonzero means warn about implicit declarations. */ 455 456int warn_implicit = 1; 457 458/* Maximum template instantiation depth. This limit is rather 459 arbitrary, but it exists to limit the time it takes to notice 460 infinite template instantiations. */ 461 462int max_tinst_depth = 500; 463 464 465 466/* The elements of `ridpointers' are identifier nodes for the reserved 467 type names and storage classes. It is indexed by a RID_... value. */ 468tree *ridpointers; 469 470tree (*make_fname_decl) (tree, int); 471 472/* Nonzero means the expression being parsed will never be evaluated. 473 This is a count, since unevaluated expressions can nest. */ 474int skip_evaluation; 475 476/* Information about how a function name is generated. */ 477struct fname_var_t 478{ 479 tree *const decl; /* pointer to the VAR_DECL. */ 480 const unsigned rid; /* RID number for the identifier. */ 481 const int pretty; /* How pretty is it? */ 482}; 483 484/* The three ways of getting then name of the current function. */ 485 486const struct fname_var_t fname_vars[] = 487{ 488 /* C99 compliant __func__, must be first. */ 489 {&c99_function_name_decl_node, RID_C99_FUNCTION_NAME, 0}, 490 /* GCC __FUNCTION__ compliant. */ 491 {&function_name_decl_node, RID_FUNCTION_NAME, 0}, 492 /* GCC __PRETTY_FUNCTION__ compliant. */ 493 {&pretty_function_name_decl_node, RID_PRETTY_FUNCTION_NAME, 1}, 494 {NULL, 0, 0}, 495}; 496 497static int constant_fits_type_p (tree, tree); 498static tree check_case_value (tree); 499static bool check_case_bounds (tree, tree, tree *, tree *); 500 501static tree handle_packed_attribute (tree *, tree, tree, int, bool *); 502static tree handle_nocommon_attribute (tree *, tree, tree, int, bool *); 503static tree handle_common_attribute (tree *, tree, tree, int, bool *); 504static tree handle_noreturn_attribute (tree *, tree, tree, int, bool *); 505static tree handle_noinline_attribute (tree *, tree, tree, int, bool *); 506static tree handle_always_inline_attribute (tree *, tree, tree, int, 507 bool *); 508static tree handle_gnu_inline_attribute (tree *, tree, tree, int, 509 bool *); 510static tree handle_flatten_attribute (tree *, tree, tree, int, bool *); 511static tree handle_used_attribute (tree *, tree, tree, int, bool *); 512static tree handle_unused_attribute (tree *, tree, tree, int, bool *); 513static tree handle_externally_visible_attribute (tree *, tree, tree, int, 514 bool *); 515static tree handle_const_attribute (tree *, tree, tree, int, bool *); 516static tree handle_transparent_union_attribute (tree *, tree, tree, 517 int, bool *); 518static tree handle_constructor_attribute (tree *, tree, tree, int, bool *); 519static tree handle_destructor_attribute (tree *, tree, tree, int, bool *); 520static tree handle_mode_attribute (tree *, tree, tree, int, bool *); 521static tree handle_section_attribute (tree *, tree, tree, int, bool *); 522static tree handle_aligned_attribute (tree *, tree, tree, int, bool *); 523static tree handle_weak_attribute (tree *, tree, tree, int, bool *) ; 524static tree handle_alias_attribute (tree *, tree, tree, int, bool *); 525static tree handle_weakref_attribute (tree *, tree, tree, int, bool *) ; 526static tree handle_visibility_attribute (tree *, tree, tree, int, 527 bool *); 528static tree handle_tls_model_attribute (tree *, tree, tree, int, 529 bool *); 530static tree handle_no_instrument_function_attribute (tree *, tree, 531 tree, int, bool *); 532static tree handle_malloc_attribute (tree *, tree, tree, int, bool *); 533static tree handle_returns_twice_attribute (tree *, tree, tree, int, bool *); 534static tree handle_no_limit_stack_attribute (tree *, tree, tree, int, 535 bool *); 536static tree handle_pure_attribute (tree *, tree, tree, int, bool *); 537static tree handle_novops_attribute (tree *, tree, tree, int, bool *); 538static tree handle_deprecated_attribute (tree *, tree, tree, int, 539 bool *); 540static tree handle_vector_size_attribute (tree *, tree, tree, int, 541 bool *); 542static tree handle_nonnull_attribute (tree *, tree, tree, int, bool *); 543static tree handle_nothrow_attribute (tree *, tree, tree, int, bool *); 544static tree handle_cleanup_attribute (tree *, tree, tree, int, bool *); 545static tree handle_warn_unused_result_attribute (tree *, tree, tree, int, 546 bool *); 547static tree handle_sentinel_attribute (tree *, tree, tree, int, bool *); 548 549static void check_function_nonnull (tree, tree); 550static void check_nonnull_arg (void *, tree, unsigned HOST_WIDE_INT); 551static bool nonnull_check_p (tree, unsigned HOST_WIDE_INT); 552static bool get_nonnull_operand (tree, unsigned HOST_WIDE_INT *); 553static int resort_field_decl_cmp (const void *, const void *); 554 555/* Table of machine-independent attributes common to all C-like languages. */ 556const struct attribute_spec c_common_attribute_table[] = 557{ 558 /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */ 559 { "packed", 0, 0, false, false, false, 560 handle_packed_attribute }, 561 { "nocommon", 0, 0, true, false, false, 562 handle_nocommon_attribute }, 563 { "common", 0, 0, true, false, false, 564 handle_common_attribute }, 565 /* FIXME: logically, noreturn attributes should be listed as 566 "false, true, true" and apply to function types. But implementing this 567 would require all the places in the compiler that use TREE_THIS_VOLATILE 568 on a decl to identify non-returning functions to be located and fixed 569 to check the function type instead. */ 570 { "noreturn", 0, 0, true, false, false, 571 handle_noreturn_attribute }, 572 { "volatile", 0, 0, true, false, false, 573 handle_noreturn_attribute }, 574 { "noinline", 0, 0, true, false, false, 575 handle_noinline_attribute }, 576 { "always_inline", 0, 0, true, false, false, 577 handle_always_inline_attribute }, 578 { "gnu_inline", 0, 0, true, false, false, 579 handle_gnu_inline_attribute }, 580 { "flatten", 0, 0, true, false, false, 581 handle_flatten_attribute }, 582 { "used", 0, 0, true, false, false, 583 handle_used_attribute }, 584 { "unused", 0, 0, false, false, false, 585 handle_unused_attribute }, 586 { "externally_visible", 0, 0, true, false, false, 587 handle_externally_visible_attribute }, 588 /* The same comments as for noreturn attributes apply to const ones. */ 589 { "const", 0, 0, true, false, false, 590 handle_const_attribute }, 591 { "transparent_union", 0, 0, false, false, false, 592 handle_transparent_union_attribute }, 593 { "constructor", 0, 0, true, false, false, 594 handle_constructor_attribute }, 595 { "destructor", 0, 0, true, false, false, 596 handle_destructor_attribute }, 597 { "mode", 1, 1, false, true, false, 598 handle_mode_attribute }, 599 { "section", 1, 1, true, false, false, 600 handle_section_attribute }, 601 { "aligned", 0, 1, false, false, false, 602 handle_aligned_attribute }, 603 { "weak", 0, 0, true, false, false, 604 handle_weak_attribute }, 605 { "alias", 1, 1, true, false, false, 606 handle_alias_attribute }, 607 { "weakref", 0, 1, true, false, false, 608 handle_weakref_attribute }, 609 { "no_instrument_function", 0, 0, true, false, false, 610 handle_no_instrument_function_attribute }, 611 { "malloc", 0, 0, true, false, false, 612 handle_malloc_attribute }, 613 { "returns_twice", 0, 0, true, false, false, 614 handle_returns_twice_attribute }, 615 { "no_stack_limit", 0, 0, true, false, false, 616 handle_no_limit_stack_attribute }, 617 { "pure", 0, 0, true, false, false, 618 handle_pure_attribute }, 619 /* For internal use (marking of builtins) only. The name contains space 620 to prevent its usage in source code. */ 621 { "no vops", 0, 0, true, false, false, 622 handle_novops_attribute }, 623 { "deprecated", 0, 0, false, false, false, 624 handle_deprecated_attribute }, 625 { "vector_size", 1, 1, false, true, false, 626 handle_vector_size_attribute }, 627 { "visibility", 1, 1, false, false, false, 628 handle_visibility_attribute }, 629 { "tls_model", 1, 1, true, false, false, 630 handle_tls_model_attribute }, 631 { "nonnull", 0, -1, false, true, true, 632 handle_nonnull_attribute }, 633 { "nothrow", 0, 0, true, false, false, 634 handle_nothrow_attribute }, 635 { "may_alias", 0, 0, false, true, false, NULL }, 636 { "cleanup", 1, 1, true, false, false, 637 handle_cleanup_attribute }, 638 { "warn_unused_result", 0, 0, false, true, true, 639 handle_warn_unused_result_attribute }, 640 { "sentinel", 0, 1, false, true, true, 641 handle_sentinel_attribute }, 642 { NULL, 0, 0, false, false, false, NULL } 643}; 644 645/* Give the specifications for the format attributes, used by C and all 646 descendants. */ 647 648const struct attribute_spec c_common_format_attribute_table[] = 649{ 650 /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */ 651 { "format", 3, 3, false, true, true, 652 handle_format_attribute }, 653 { "format_arg", 1, 1, false, true, true, 654 handle_format_arg_attribute }, 655 { NULL, 0, 0, false, false, false, NULL } 656}; 657 658/* Push current bindings for the function name VAR_DECLS. */ 659 660void 661start_fname_decls (void) 662{ 663 unsigned ix; 664 tree saved = NULL_TREE; 665 666 for (ix = 0; fname_vars[ix].decl; ix++) 667 { 668 tree decl = *fname_vars[ix].decl; 669 670 if (decl) 671 { 672 saved = tree_cons (decl, build_int_cst (NULL_TREE, ix), saved); 673 *fname_vars[ix].decl = NULL_TREE; 674 } 675 } 676 if (saved || saved_function_name_decls) 677 /* Normally they'll have been NULL, so only push if we've got a 678 stack, or they are non-NULL. */ 679 saved_function_name_decls = tree_cons (saved, NULL_TREE, 680 saved_function_name_decls); 681} 682 683/* Finish up the current bindings, adding them into the current function's 684 statement tree. This must be done _before_ finish_stmt_tree is called. 685 If there is no current function, we must be at file scope and no statements 686 are involved. Pop the previous bindings. */ 687 688void 689finish_fname_decls (void) 690{ 691 unsigned ix; 692 tree stmts = NULL_TREE; 693 tree stack = saved_function_name_decls; 694 695 for (; stack && TREE_VALUE (stack); stack = TREE_CHAIN (stack)) 696 append_to_statement_list (TREE_VALUE (stack), &stmts); 697 698 if (stmts) 699 { 700 tree *bodyp = &DECL_SAVED_TREE (current_function_decl); 701 702 if (TREE_CODE (*bodyp) == BIND_EXPR) 703 bodyp = &BIND_EXPR_BODY (*bodyp); 704 705 append_to_statement_list_force (*bodyp, &stmts); 706 *bodyp = stmts; 707 } 708 709 for (ix = 0; fname_vars[ix].decl; ix++) 710 *fname_vars[ix].decl = NULL_TREE; 711 712 if (stack) 713 { 714 /* We had saved values, restore them. */ 715 tree saved; 716 717 for (saved = TREE_PURPOSE (stack); saved; saved = TREE_CHAIN (saved)) 718 { 719 tree decl = TREE_PURPOSE (saved); 720 unsigned ix = TREE_INT_CST_LOW (TREE_VALUE (saved)); 721 722 *fname_vars[ix].decl = decl; 723 } 724 stack = TREE_CHAIN (stack); 725 } 726 saved_function_name_decls = stack; 727} 728 729/* Return the text name of the current function, suitably prettified 730 by PRETTY_P. Return string must be freed by caller. */ 731 732const char * 733fname_as_string (int pretty_p) 734{ 735 const char *name = "top level"; 736 char *namep; 737 int vrb = 2; 738 739 if (!pretty_p) 740 { 741 name = ""; 742 vrb = 0; 743 } 744 745 if (current_function_decl) 746 name = lang_hooks.decl_printable_name (current_function_decl, vrb); 747 748 if (c_lex_string_translate) 749 { 750 int len = strlen (name) + 3; /* Two for '"'s. One for NULL. */ 751 cpp_string cstr = { 0, 0 }, strname; 752 753 namep = XNEWVEC (char, len); 754 snprintf (namep, len, "\"%s\"", name); 755 strname.text = (unsigned char *) namep; 756 strname.len = len - 1; 757 758 if (cpp_interpret_string (parse_in, &strname, 1, &cstr, false)) 759 { 760 XDELETEVEC (namep); 761 return (char *) cstr.text; 762 } 763 } 764 else 765 namep = xstrdup (name); 766 767 return namep; 768} 769 770/* Expand DECL if it declares an entity not handled by the 771 common code. */ 772 773int 774c_expand_decl (tree decl) 775{ 776 if (TREE_CODE (decl) == VAR_DECL && !TREE_STATIC (decl)) 777 { 778 /* Let the back-end know about this variable. */ 779 if (!anon_aggr_type_p (TREE_TYPE (decl))) 780 emit_local_var (decl); 781 else 782 expand_anon_union_decl (decl, NULL_TREE, 783 DECL_ANON_UNION_ELEMS (decl)); 784 } 785 else 786 return 0; 787 788 return 1; 789} 790 791 792/* Return the VAR_DECL for a const char array naming the current 793 function. If the VAR_DECL has not yet been created, create it 794 now. RID indicates how it should be formatted and IDENTIFIER_NODE 795 ID is its name (unfortunately C and C++ hold the RID values of 796 keywords in different places, so we can't derive RID from ID in 797 this language independent code. */ 798 799tree 800fname_decl (unsigned int rid, tree id) 801{ 802 unsigned ix; 803 tree decl = NULL_TREE; 804 805 for (ix = 0; fname_vars[ix].decl; ix++) 806 if (fname_vars[ix].rid == rid) 807 break; 808 809 decl = *fname_vars[ix].decl; 810 if (!decl) 811 { 812 /* If a tree is built here, it would normally have the lineno of 813 the current statement. Later this tree will be moved to the 814 beginning of the function and this line number will be wrong. 815 To avoid this problem set the lineno to 0 here; that prevents 816 it from appearing in the RTL. */ 817 tree stmts; 818 location_t saved_location = input_location; 819#ifdef USE_MAPPED_LOCATION 820 input_location = UNKNOWN_LOCATION; 821#else 822 input_line = 0; 823#endif 824 825 stmts = push_stmt_list (); 826 decl = (*make_fname_decl) (id, fname_vars[ix].pretty); 827 stmts = pop_stmt_list (stmts); 828 if (!IS_EMPTY_STMT (stmts)) 829 saved_function_name_decls 830 = tree_cons (decl, stmts, saved_function_name_decls); 831 *fname_vars[ix].decl = decl; 832 input_location = saved_location; 833 } 834 if (!ix && !current_function_decl) 835 pedwarn ("%qD is not defined outside of function scope", decl); 836 837 return decl; 838} 839 840/* Given a STRING_CST, give it a suitable array-of-chars data type. */ 841 842tree 843fix_string_type (tree value) 844{ 845 const int wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT; 846 const int wide_flag = TREE_TYPE (value) == wchar_array_type_node; 847 int length = TREE_STRING_LENGTH (value); 848 int nchars; 849 tree e_type, i_type, a_type; 850 851 /* Compute the number of elements, for the array type. */ 852 nchars = wide_flag ? length / wchar_bytes : length; 853 854 /* C89 2.2.4.1, C99 5.2.4.1 (Translation limits). The analogous 855 limit in C++98 Annex B is very large (65536) and is not normative, 856 so we do not diagnose it (warn_overlength_strings is forced off 857 in c_common_post_options). */ 858 if (warn_overlength_strings) 859 { 860 const int nchars_max = flag_isoc99 ? 4095 : 509; 861 const int relevant_std = flag_isoc99 ? 99 : 90; 862 if (nchars - 1 > nchars_max) 863 /* Translators: The %d after 'ISO C' will be 90 or 99. Do not 864 separate the %d from the 'C'. 'ISO' should not be 865 translated, but it may be moved after 'C%d' in languages 866 where modifiers follow nouns. */ 867 pedwarn ("string length %qd is greater than the length %qd " 868 "ISO C%d compilers are required to support", 869 nchars - 1, nchars_max, relevant_std); 870 } 871 872 /* Create the array type for the string constant. The ISO C++ 873 standard says that a string literal has type `const char[N]' or 874 `const wchar_t[N]'. We use the same logic when invoked as a C 875 front-end with -Wwrite-strings. 876 ??? We should change the type of an expression depending on the 877 state of a warning flag. We should just be warning -- see how 878 this is handled in the C++ front-end for the deprecated implicit 879 conversion from string literals to `char*' or `wchar_t*'. 880 881 The C++ front end relies on TYPE_MAIN_VARIANT of a cv-qualified 882 array type being the unqualified version of that type. 883 Therefore, if we are constructing an array of const char, we must 884 construct the matching unqualified array type first. The C front 885 end does not require this, but it does no harm, so we do it 886 unconditionally. */ 887 e_type = wide_flag ? wchar_type_node : char_type_node; 888 i_type = build_index_type (build_int_cst (NULL_TREE, nchars - 1)); 889 a_type = build_array_type (e_type, i_type); 890 if (c_dialect_cxx() || warn_write_strings) 891 a_type = c_build_qualified_type (a_type, TYPE_QUAL_CONST); 892 893 TREE_TYPE (value) = a_type; 894 TREE_CONSTANT (value) = 1; 895 TREE_INVARIANT (value) = 1; 896 TREE_READONLY (value) = 1; 897 TREE_STATIC (value) = 1; 898 return value; 899} 900 901/* Print a warning if a constant expression had overflow in folding. 902 Invoke this function on every expression that the language 903 requires to be a constant expression. 904 Note the ANSI C standard says it is erroneous for a 905 constant expression to overflow. */ 906 907void 908constant_expression_warning (tree value) 909{ 910 if ((TREE_CODE (value) == INTEGER_CST || TREE_CODE (value) == REAL_CST 911 || TREE_CODE (value) == VECTOR_CST 912 || TREE_CODE (value) == COMPLEX_CST) 913 && TREE_CONSTANT_OVERFLOW (value) 914 && warn_overflow 915 && pedantic) 916 pedwarn ("overflow in constant expression"); 917} 918 919/* Print a warning if an expression had overflow in folding and its 920 operands hadn't. 921 922 Invoke this function on every expression that 923 (1) appears in the source code, and 924 (2) is a constant expression that overflowed, and 925 (3) is not already checked by convert_and_check; 926 however, do not invoke this function on operands of explicit casts 927 or when the expression is the result of an operator and any operand 928 already overflowed. */ 929 930void 931overflow_warning (tree value) 932{ 933 if (skip_evaluation) return; 934 935 switch (TREE_CODE (value)) 936 { 937 case INTEGER_CST: 938 warning (OPT_Woverflow, "integer overflow in expression"); 939 break; 940 941 case REAL_CST: 942 warning (OPT_Woverflow, "floating point overflow in expression"); 943 break; 944 945 case VECTOR_CST: 946 warning (OPT_Woverflow, "vector overflow in expression"); 947 break; 948 949 case COMPLEX_CST: 950 if (TREE_CODE (TREE_REALPART (value)) == INTEGER_CST) 951 warning (OPT_Woverflow, "complex integer overflow in expression"); 952 else if (TREE_CODE (TREE_REALPART (value)) == REAL_CST) 953 warning (OPT_Woverflow, "complex floating point overflow in expression"); 954 break; 955 956 default: 957 break; 958 } 959} 960 961/* Print a warning if a large constant is truncated to unsigned, 962 or if -Wconversion is used and a constant < 0 is converted to unsigned. 963 Invoke this function on every expression that might be implicitly 964 converted to an unsigned type. */ 965 966static void 967unsigned_conversion_warning (tree result, tree operand) 968{ 969 tree type = TREE_TYPE (result); 970 971 if (TREE_CODE (operand) == INTEGER_CST 972 && TREE_CODE (type) == INTEGER_TYPE 973 && TYPE_UNSIGNED (type) 974 && skip_evaluation == 0 975 && !int_fits_type_p (operand, type)) 976 { 977 if (!int_fits_type_p (operand, c_common_signed_type (type))) 978 /* This detects cases like converting -129 or 256 to unsigned char. */ 979 warning (OPT_Woverflow, 980 "large integer implicitly truncated to unsigned type"); 981 else 982 warning (OPT_Wconversion, 983 "negative integer implicitly converted to unsigned type"); 984 } 985} 986 987/* Print a warning about casts that might indicate violation 988 of strict aliasing rules if -Wstrict-aliasing is used and 989 strict aliasing mode is in effect. OTYPE is the original 990 TREE_TYPE of EXPR, and TYPE the type we're casting to. */ 991 992bool 993strict_aliasing_warning (tree otype, tree type, tree expr) 994{ 995 if (!(flag_strict_aliasing && POINTER_TYPE_P (type) 996 && POINTER_TYPE_P (otype) && !VOID_TYPE_P (TREE_TYPE (type)))) 997 return false; 998 999 if ((warn_strict_aliasing > 1) && TREE_CODE (expr) == ADDR_EXPR 1000 && (DECL_P (TREE_OPERAND (expr, 0)) 1001 || handled_component_p (TREE_OPERAND (expr, 0)))) 1002 { 1003 /* Casting the address of an object to non void pointer. Warn 1004 if the cast breaks type based aliasing. */ 1005 if (!COMPLETE_TYPE_P (TREE_TYPE (type)) && warn_strict_aliasing == 2) 1006 { 1007 warning (OPT_Wstrict_aliasing, "type-punning to incomplete type " 1008 "might break strict-aliasing rules"); 1009 return true; 1010 } 1011 else 1012 { 1013 /* warn_strict_aliasing >= 3. This includes the default (3). 1014 Only warn if the cast is dereferenced immediately. */ 1015 HOST_WIDE_INT set1 = 1016 get_alias_set (TREE_TYPE (TREE_OPERAND (expr, 0))); 1017 HOST_WIDE_INT set2 = get_alias_set (TREE_TYPE (type)); 1018 1019 if (!alias_sets_conflict_p (set1, set2)) 1020 { 1021 warning (OPT_Wstrict_aliasing, "dereferencing type-punned " 1022 "pointer will break strict-aliasing rules"); 1023 return true; 1024 } 1025 else if (warn_strict_aliasing == 2 1026 && !alias_sets_might_conflict_p (set1, set2)) 1027 { 1028 warning (OPT_Wstrict_aliasing, "dereferencing type-punned " 1029 "pointer might break strict-aliasing rules"); 1030 return true; 1031 } 1032 } 1033 } 1034 else 1035 if ((warn_strict_aliasing == 1) && !VOID_TYPE_P (TREE_TYPE (otype))) 1036 { 1037 /* At this level, warn for any conversions, even if an address is 1038 not taken in the same statement. This will likely produce many 1039 false positives, but could be useful to pinpoint problems that 1040 are not revealed at higher levels. */ 1041 HOST_WIDE_INT set1 = get_alias_set (TREE_TYPE (otype)); 1042 HOST_WIDE_INT set2 = get_alias_set (TREE_TYPE (type)); 1043 if (!COMPLETE_TYPE_P(type) 1044 || !alias_sets_might_conflict_p (set1, set2)) 1045 { 1046 warning (OPT_Wstrict_aliasing, "dereferencing type-punned " 1047 "pointer might break strict-aliasing rules"); 1048 return true; 1049 } 1050 } 1051 1052 return false; 1053} 1054 1055 1056/* Print a warning about if (); or if () .. else; constructs 1057 via the special empty statement node that we create. INNER_THEN 1058 and INNER_ELSE are the statement lists of the if and the else 1059 block. */ 1060 1061void 1062empty_body_warning (tree inner_then, tree inner_else) 1063{ 1064 if (extra_warnings) 1065 { 1066 if (TREE_CODE (inner_then) == STATEMENT_LIST 1067 && STATEMENT_LIST_TAIL (inner_then)) 1068 inner_then = STATEMENT_LIST_TAIL (inner_then)->stmt; 1069 1070 if (inner_else && TREE_CODE (inner_else) == STATEMENT_LIST 1071 && STATEMENT_LIST_TAIL (inner_else)) 1072 inner_else = STATEMENT_LIST_TAIL (inner_else)->stmt; 1073 1074 if (IS_EMPTY_STMT (inner_then) && !inner_else) 1075 warning (OPT_Wextra, "%Hempty body in an if-statement", 1076 EXPR_LOCUS (inner_then)); 1077 1078 if (inner_else && IS_EMPTY_STMT (inner_else)) 1079 warning (OPT_Wextra, "%Hempty body in an else-statement", 1080 EXPR_LOCUS (inner_else)); 1081 } 1082} 1083 1084 1085/* Nonzero if constant C has a value that is permissible 1086 for type TYPE (an INTEGER_TYPE). */ 1087 1088static int 1089constant_fits_type_p (tree c, tree type) 1090{ 1091 if (TREE_CODE (c) == INTEGER_CST) 1092 return int_fits_type_p (c, type); 1093 1094 c = convert (type, c); 1095 return !TREE_OVERFLOW (c); 1096} 1097 1098/* Nonzero if vector types T1 and T2 can be converted to each other 1099 without an explicit cast. */ 1100int 1101vector_types_convertible_p (tree t1, tree t2) 1102{ 1103 return targetm.vector_opaque_p (t1) 1104 || targetm.vector_opaque_p (t2) 1105 || (tree_int_cst_equal (TYPE_SIZE (t1), TYPE_SIZE (t2)) 1106 && (TREE_CODE (TREE_TYPE (t1)) != REAL_TYPE || 1107 TYPE_PRECISION (t1) == TYPE_PRECISION (t2)) 1108 && INTEGRAL_TYPE_P (TREE_TYPE (t1)) 1109 == INTEGRAL_TYPE_P (TREE_TYPE (t2))); 1110} 1111 1112/* Convert EXPR to TYPE, warning about conversion problems with constants. 1113 Invoke this function on every expression that is converted implicitly, 1114 i.e. because of language rules and not because of an explicit cast. */ 1115 1116tree 1117convert_and_check (tree type, tree expr) 1118{ 1119 tree t = convert (type, expr); 1120 if (TREE_CODE (t) == INTEGER_CST) 1121 { 1122 if (TREE_OVERFLOW (t)) 1123 { 1124 TREE_OVERFLOW (t) = 0; 1125 1126 /* Do not diagnose overflow in a constant expression merely 1127 because a conversion overflowed. */ 1128 TREE_CONSTANT_OVERFLOW (t) = CONSTANT_CLASS_P (expr) 1129 && TREE_CONSTANT_OVERFLOW (expr); 1130 1131 /* No warning for converting 0x80000000 to int. */ 1132 if (!(TYPE_UNSIGNED (type) < TYPE_UNSIGNED (TREE_TYPE (expr)) 1133 && TREE_CODE (TREE_TYPE (expr)) == INTEGER_TYPE 1134 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (expr)))) 1135 /* If EXPR fits in the unsigned version of TYPE, 1136 don't warn unless pedantic. */ 1137 if ((pedantic 1138 || TYPE_UNSIGNED (type) 1139 || !constant_fits_type_p (expr, 1140 c_common_unsigned_type (type))) 1141 && skip_evaluation == 0) 1142 warning (OPT_Woverflow, 1143 "overflow in implicit constant conversion"); 1144 } 1145 else 1146 unsigned_conversion_warning (t, expr); 1147 } 1148 return t; 1149} 1150 1151/* A node in a list that describes references to variables (EXPR), which are 1152 either read accesses if WRITER is zero, or write accesses, in which case 1153 WRITER is the parent of EXPR. */ 1154struct tlist 1155{ 1156 struct tlist *next; 1157 tree expr, writer; 1158}; 1159 1160/* Used to implement a cache the results of a call to verify_tree. We only 1161 use this for SAVE_EXPRs. */ 1162struct tlist_cache 1163{ 1164 struct tlist_cache *next; 1165 struct tlist *cache_before_sp; 1166 struct tlist *cache_after_sp; 1167 tree expr; 1168}; 1169 1170/* Obstack to use when allocating tlist structures, and corresponding 1171 firstobj. */ 1172static struct obstack tlist_obstack; 1173static char *tlist_firstobj = 0; 1174 1175/* Keep track of the identifiers we've warned about, so we can avoid duplicate 1176 warnings. */ 1177static struct tlist *warned_ids; 1178/* SAVE_EXPRs need special treatment. We process them only once and then 1179 cache the results. */ 1180static struct tlist_cache *save_expr_cache; 1181 1182static void add_tlist (struct tlist **, struct tlist *, tree, int); 1183static void merge_tlist (struct tlist **, struct tlist *, int); 1184static void verify_tree (tree, struct tlist **, struct tlist **, tree); 1185static int warning_candidate_p (tree); 1186static void warn_for_collisions (struct tlist *); 1187static void warn_for_collisions_1 (tree, tree, struct tlist *, int); 1188static struct tlist *new_tlist (struct tlist *, tree, tree); 1189 1190/* Create a new struct tlist and fill in its fields. */ 1191static struct tlist * 1192new_tlist (struct tlist *next, tree t, tree writer) 1193{ 1194 struct tlist *l; 1195 l = XOBNEW (&tlist_obstack, struct tlist); 1196 l->next = next; 1197 l->expr = t; 1198 l->writer = writer; 1199 return l; 1200} 1201 1202/* Add duplicates of the nodes found in ADD to the list *TO. If EXCLUDE_WRITER 1203 is nonnull, we ignore any node we find which has a writer equal to it. */ 1204 1205static void 1206add_tlist (struct tlist **to, struct tlist *add, tree exclude_writer, int copy) 1207{ 1208 while (add) 1209 { 1210 struct tlist *next = add->next; 1211 if (!copy) 1212 add->next = *to; 1213 if (!exclude_writer || add->writer != exclude_writer) 1214 *to = copy ? new_tlist (*to, add->expr, add->writer) : add; 1215 add = next; 1216 } 1217} 1218 1219/* Merge the nodes of ADD into TO. This merging process is done so that for 1220 each variable that already exists in TO, no new node is added; however if 1221 there is a write access recorded in ADD, and an occurrence on TO is only 1222 a read access, then the occurrence in TO will be modified to record the 1223 write. */ 1224 1225static void 1226merge_tlist (struct tlist **to, struct tlist *add, int copy) 1227{ 1228 struct tlist **end = to; 1229 1230 while (*end) 1231 end = &(*end)->next; 1232 1233 while (add) 1234 { 1235 int found = 0; 1236 struct tlist *tmp2; 1237 struct tlist *next = add->next; 1238 1239 for (tmp2 = *to; tmp2; tmp2 = tmp2->next) 1240 if (tmp2->expr == add->expr) 1241 { 1242 found = 1; 1243 if (!tmp2->writer) 1244 tmp2->writer = add->writer; 1245 } 1246 if (!found) 1247 { 1248 *end = copy ? add : new_tlist (NULL, add->expr, add->writer); 1249 end = &(*end)->next; 1250 *end = 0; 1251 } 1252 add = next; 1253 } 1254} 1255 1256/* WRITTEN is a variable, WRITER is its parent. Warn if any of the variable 1257 references in list LIST conflict with it, excluding reads if ONLY writers 1258 is nonzero. */ 1259 1260static void 1261warn_for_collisions_1 (tree written, tree writer, struct tlist *list, 1262 int only_writes) 1263{ 1264 struct tlist *tmp; 1265 1266 /* Avoid duplicate warnings. */ 1267 for (tmp = warned_ids; tmp; tmp = tmp->next) 1268 if (tmp->expr == written) 1269 return; 1270 1271 while (list) 1272 { 1273 if (list->expr == written 1274 && list->writer != writer 1275 && (!only_writes || list->writer) 1276 && DECL_NAME (list->expr)) 1277 { 1278 warned_ids = new_tlist (warned_ids, written, NULL_TREE); 1279 warning (0, "operation on %qE may be undefined", list->expr); 1280 } 1281 list = list->next; 1282 } 1283} 1284 1285/* Given a list LIST of references to variables, find whether any of these 1286 can cause conflicts due to missing sequence points. */ 1287 1288static void 1289warn_for_collisions (struct tlist *list) 1290{ 1291 struct tlist *tmp; 1292 1293 for (tmp = list; tmp; tmp = tmp->next) 1294 { 1295 if (tmp->writer) 1296 warn_for_collisions_1 (tmp->expr, tmp->writer, list, 0); 1297 } 1298} 1299 1300/* Return nonzero if X is a tree that can be verified by the sequence point 1301 warnings. */ 1302static int 1303warning_candidate_p (tree x) 1304{ 1305 return TREE_CODE (x) == VAR_DECL || TREE_CODE (x) == PARM_DECL; 1306} 1307 1308/* Walk the tree X, and record accesses to variables. If X is written by the 1309 parent tree, WRITER is the parent. 1310 We store accesses in one of the two lists: PBEFORE_SP, and PNO_SP. If this 1311 expression or its only operand forces a sequence point, then everything up 1312 to the sequence point is stored in PBEFORE_SP. Everything else gets stored 1313 in PNO_SP. 1314 Once we return, we will have emitted warnings if any subexpression before 1315 such a sequence point could be undefined. On a higher level, however, the 1316 sequence point may not be relevant, and we'll merge the two lists. 1317 1318 Example: (b++, a) + b; 1319 The call that processes the COMPOUND_EXPR will store the increment of B 1320 in PBEFORE_SP, and the use of A in PNO_SP. The higher-level call that 1321 processes the PLUS_EXPR will need to merge the two lists so that 1322 eventually, all accesses end up on the same list (and we'll warn about the 1323 unordered subexpressions b++ and b. 1324 1325 A note on merging. If we modify the former example so that our expression 1326 becomes 1327 (b++, b) + a 1328 care must be taken not simply to add all three expressions into the final 1329 PNO_SP list. The function merge_tlist takes care of that by merging the 1330 before-SP list of the COMPOUND_EXPR into its after-SP list in a special 1331 way, so that no more than one access to B is recorded. */ 1332 1333static void 1334verify_tree (tree x, struct tlist **pbefore_sp, struct tlist **pno_sp, 1335 tree writer) 1336{ 1337 struct tlist *tmp_before, *tmp_nosp, *tmp_list2, *tmp_list3; 1338 enum tree_code code; 1339 enum tree_code_class cl; 1340 1341 /* X may be NULL if it is the operand of an empty statement expression 1342 ({ }). */ 1343 if (x == NULL) 1344 return; 1345 1346 restart: 1347 code = TREE_CODE (x); 1348 cl = TREE_CODE_CLASS (code); 1349 1350 if (warning_candidate_p (x)) 1351 { 1352 *pno_sp = new_tlist (*pno_sp, x, writer); 1353 return; 1354 } 1355 1356 switch (code) 1357 { 1358 case CONSTRUCTOR: 1359 return; 1360 1361 case COMPOUND_EXPR: 1362 case TRUTH_ANDIF_EXPR: 1363 case TRUTH_ORIF_EXPR: 1364 tmp_before = tmp_nosp = tmp_list3 = 0; 1365 verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE); 1366 warn_for_collisions (tmp_nosp); 1367 merge_tlist (pbefore_sp, tmp_before, 0); 1368 merge_tlist (pbefore_sp, tmp_nosp, 0); 1369 verify_tree (TREE_OPERAND (x, 1), &tmp_list3, pno_sp, NULL_TREE); 1370 merge_tlist (pbefore_sp, tmp_list3, 0); 1371 return; 1372 1373 case COND_EXPR: 1374 tmp_before = tmp_list2 = 0; 1375 verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_list2, NULL_TREE); 1376 warn_for_collisions (tmp_list2); 1377 merge_tlist (pbefore_sp, tmp_before, 0); 1378 merge_tlist (pbefore_sp, tmp_list2, 1); 1379 1380 tmp_list3 = tmp_nosp = 0; 1381 verify_tree (TREE_OPERAND (x, 1), &tmp_list3, &tmp_nosp, NULL_TREE); 1382 warn_for_collisions (tmp_nosp); 1383 merge_tlist (pbefore_sp, tmp_list3, 0); 1384 1385 tmp_list3 = tmp_list2 = 0; 1386 verify_tree (TREE_OPERAND (x, 2), &tmp_list3, &tmp_list2, NULL_TREE); 1387 warn_for_collisions (tmp_list2); 1388 merge_tlist (pbefore_sp, tmp_list3, 0); 1389 /* Rather than add both tmp_nosp and tmp_list2, we have to merge the 1390 two first, to avoid warning for (a ? b++ : b++). */ 1391 merge_tlist (&tmp_nosp, tmp_list2, 0); 1392 add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0); 1393 return; 1394 1395 case PREDECREMENT_EXPR: 1396 case PREINCREMENT_EXPR: 1397 case POSTDECREMENT_EXPR: 1398 case POSTINCREMENT_EXPR: 1399 verify_tree (TREE_OPERAND (x, 0), pno_sp, pno_sp, x); 1400 return; 1401 1402 case MODIFY_EXPR: 1403 tmp_before = tmp_nosp = tmp_list3 = 0; 1404 verify_tree (TREE_OPERAND (x, 1), &tmp_before, &tmp_nosp, NULL_TREE); 1405 verify_tree (TREE_OPERAND (x, 0), &tmp_list3, &tmp_list3, x); 1406 /* Expressions inside the LHS are not ordered wrt. the sequence points 1407 in the RHS. Example: 1408 *a = (a++, 2) 1409 Despite the fact that the modification of "a" is in the before_sp 1410 list (tmp_before), it conflicts with the use of "a" in the LHS. 1411 We can handle this by adding the contents of tmp_list3 1412 to those of tmp_before, and redoing the collision warnings for that 1413 list. */ 1414 add_tlist (&tmp_before, tmp_list3, x, 1); 1415 warn_for_collisions (tmp_before); 1416 /* Exclude the LHS itself here; we first have to merge it into the 1417 tmp_nosp list. This is done to avoid warning for "a = a"; if we 1418 didn't exclude the LHS, we'd get it twice, once as a read and once 1419 as a write. */ 1420 add_tlist (pno_sp, tmp_list3, x, 0); 1421 warn_for_collisions_1 (TREE_OPERAND (x, 0), x, tmp_nosp, 1); 1422 1423 merge_tlist (pbefore_sp, tmp_before, 0); 1424 if (warning_candidate_p (TREE_OPERAND (x, 0))) 1425 merge_tlist (&tmp_nosp, new_tlist (NULL, TREE_OPERAND (x, 0), x), 0); 1426 add_tlist (pno_sp, tmp_nosp, NULL_TREE, 1); 1427 return; 1428 1429 case CALL_EXPR: 1430 /* We need to warn about conflicts among arguments and conflicts between 1431 args and the function address. Side effects of the function address, 1432 however, are not ordered by the sequence point of the call. */ 1433 tmp_before = tmp_nosp = tmp_list2 = tmp_list3 = 0; 1434 verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE); 1435 if (TREE_OPERAND (x, 1)) 1436 verify_tree (TREE_OPERAND (x, 1), &tmp_list2, &tmp_list3, NULL_TREE); 1437 merge_tlist (&tmp_list3, tmp_list2, 0); 1438 add_tlist (&tmp_before, tmp_list3, NULL_TREE, 0); 1439 add_tlist (&tmp_before, tmp_nosp, NULL_TREE, 0); 1440 warn_for_collisions (tmp_before); 1441 add_tlist (pbefore_sp, tmp_before, NULL_TREE, 0); 1442 return; 1443 1444 case TREE_LIST: 1445 /* Scan all the list, e.g. indices of multi dimensional array. */ 1446 while (x) 1447 { 1448 tmp_before = tmp_nosp = 0; 1449 verify_tree (TREE_VALUE (x), &tmp_before, &tmp_nosp, NULL_TREE); 1450 merge_tlist (&tmp_nosp, tmp_before, 0); 1451 add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0); 1452 x = TREE_CHAIN (x); 1453 } 1454 return; 1455 1456 case SAVE_EXPR: 1457 { 1458 struct tlist_cache *t; 1459 for (t = save_expr_cache; t; t = t->next) 1460 if (t->expr == x) 1461 break; 1462 1463 if (!t) 1464 { 1465 t = XOBNEW (&tlist_obstack, struct tlist_cache); 1466 t->next = save_expr_cache; 1467 t->expr = x; 1468 save_expr_cache = t; 1469 1470 tmp_before = tmp_nosp = 0; 1471 verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE); 1472 warn_for_collisions (tmp_nosp); 1473 1474 tmp_list3 = 0; 1475 while (tmp_nosp) 1476 { 1477 struct tlist *t = tmp_nosp; 1478 tmp_nosp = t->next; 1479 merge_tlist (&tmp_list3, t, 0); 1480 } 1481 t->cache_before_sp = tmp_before; 1482 t->cache_after_sp = tmp_list3; 1483 } 1484 merge_tlist (pbefore_sp, t->cache_before_sp, 1); 1485 add_tlist (pno_sp, t->cache_after_sp, NULL_TREE, 1); 1486 return; 1487 } 1488 1489 default: 1490 /* For other expressions, simply recurse on their operands. 1491 Manual tail recursion for unary expressions. 1492 Other non-expressions need not be processed. */ 1493 if (cl == tcc_unary) 1494 { 1495 x = TREE_OPERAND (x, 0); 1496 writer = 0; 1497 goto restart; 1498 } 1499 else if (IS_EXPR_CODE_CLASS (cl)) 1500 { 1501 int lp; 1502 int max = TREE_CODE_LENGTH (TREE_CODE (x)); 1503 for (lp = 0; lp < max; lp++) 1504 { 1505 tmp_before = tmp_nosp = 0; 1506 verify_tree (TREE_OPERAND (x, lp), &tmp_before, &tmp_nosp, 0); 1507 merge_tlist (&tmp_nosp, tmp_before, 0); 1508 add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0); 1509 } 1510 } 1511 return; 1512 } 1513} 1514 1515/* Try to warn for undefined behavior in EXPR due to missing sequence 1516 points. */ 1517 1518void 1519verify_sequence_points (tree expr) 1520{ 1521 struct tlist *before_sp = 0, *after_sp = 0; 1522 1523 warned_ids = 0; 1524 save_expr_cache = 0; 1525 if (tlist_firstobj == 0) 1526 { 1527 gcc_obstack_init (&tlist_obstack); 1528 tlist_firstobj = (char *) obstack_alloc (&tlist_obstack, 0); 1529 } 1530 1531 verify_tree (expr, &before_sp, &after_sp, 0); 1532 warn_for_collisions (after_sp); 1533 obstack_free (&tlist_obstack, tlist_firstobj); 1534} 1535 1536/* Validate the expression after `case' and apply default promotions. */ 1537 1538static tree 1539check_case_value (tree value) 1540{ 1541 if (value == NULL_TREE) 1542 return value; 1543 1544 /* ??? Can we ever get nops here for a valid case value? We 1545 shouldn't for C. */ 1546 STRIP_TYPE_NOPS (value); 1547 /* In C++, the following is allowed: 1548 1549 const int i = 3; 1550 switch (...) { case i: ... } 1551 1552 So, we try to reduce the VALUE to a constant that way. */ 1553 if (c_dialect_cxx ()) 1554 { 1555 value = decl_constant_value (value); 1556 STRIP_TYPE_NOPS (value); 1557 value = fold (value); 1558 } 1559 1560 if (TREE_CODE (value) == INTEGER_CST) 1561 /* Promote char or short to int. */ 1562 value = perform_integral_promotions (value); 1563 else if (value != error_mark_node) 1564 { 1565 error ("case label does not reduce to an integer constant"); 1566 value = error_mark_node; 1567 } 1568 1569 constant_expression_warning (value); 1570 1571 return value; 1572} 1573 1574/* See if the case values LOW and HIGH are in the range of the original 1575 type (i.e. before the default conversion to int) of the switch testing 1576 expression. 1577 TYPE is the promoted type of the testing expression, and ORIG_TYPE is 1578 the type before promoting it. CASE_LOW_P is a pointer to the lower 1579 bound of the case label, and CASE_HIGH_P is the upper bound or NULL 1580 if the case is not a case range. 1581 The caller has to make sure that we are not called with NULL for 1582 CASE_LOW_P (i.e. the default case). 1583 Returns true if the case label is in range of ORIG_TYPE (saturated or 1584 untouched) or false if the label is out of range. */ 1585 1586static bool 1587check_case_bounds (tree type, tree orig_type, 1588 tree *case_low_p, tree *case_high_p) 1589{ 1590 tree min_value, max_value; 1591 tree case_low = *case_low_p; 1592 tree case_high = case_high_p ? *case_high_p : case_low; 1593 1594 /* If there was a problem with the original type, do nothing. */ 1595 if (orig_type == error_mark_node) 1596 return true; 1597 1598 min_value = TYPE_MIN_VALUE (orig_type); 1599 max_value = TYPE_MAX_VALUE (orig_type); 1600 1601 /* Case label is less than minimum for type. */ 1602 if (tree_int_cst_compare (case_low, min_value) < 0 1603 && tree_int_cst_compare (case_high, min_value) < 0) 1604 { 1605 warning (0, "case label value is less than minimum value for type"); 1606 return false; 1607 } 1608 1609 /* Case value is greater than maximum for type. */ 1610 if (tree_int_cst_compare (case_low, max_value) > 0 1611 && tree_int_cst_compare (case_high, max_value) > 0) 1612 { 1613 warning (0, "case label value exceeds maximum value for type"); 1614 return false; 1615 } 1616 1617 /* Saturate lower case label value to minimum. */ 1618 if (tree_int_cst_compare (case_high, min_value) >= 0 1619 && tree_int_cst_compare (case_low, min_value) < 0) 1620 { 1621 warning (0, "lower value in case label range" 1622 " less than minimum value for type"); 1623 case_low = min_value; 1624 } 1625 1626 /* Saturate upper case label value to maximum. */ 1627 if (tree_int_cst_compare (case_low, max_value) <= 0 1628 && tree_int_cst_compare (case_high, max_value) > 0) 1629 { 1630 warning (0, "upper value in case label range" 1631 " exceeds maximum value for type"); 1632 case_high = max_value; 1633 } 1634 1635 if (*case_low_p != case_low) 1636 *case_low_p = convert (type, case_low); 1637 if (case_high_p && *case_high_p != case_high) 1638 *case_high_p = convert (type, case_high); 1639 1640 return true; 1641} 1642 1643/* Return an integer type with BITS bits of precision, 1644 that is unsigned if UNSIGNEDP is nonzero, otherwise signed. */ 1645 1646tree 1647c_common_type_for_size (unsigned int bits, int unsignedp) 1648{ 1649 if (bits == TYPE_PRECISION (integer_type_node)) 1650 return unsignedp ? unsigned_type_node : integer_type_node; 1651 1652 if (bits == TYPE_PRECISION (signed_char_type_node)) 1653 return unsignedp ? unsigned_char_type_node : signed_char_type_node; 1654 1655 if (bits == TYPE_PRECISION (short_integer_type_node)) 1656 return unsignedp ? short_unsigned_type_node : short_integer_type_node; 1657 1658 if (bits == TYPE_PRECISION (long_integer_type_node)) 1659 return unsignedp ? long_unsigned_type_node : long_integer_type_node; 1660 1661 if (bits == TYPE_PRECISION (long_long_integer_type_node)) 1662 return (unsignedp ? long_long_unsigned_type_node 1663 : long_long_integer_type_node); 1664 1665 if (bits == TYPE_PRECISION (widest_integer_literal_type_node)) 1666 return (unsignedp ? widest_unsigned_literal_type_node 1667 : widest_integer_literal_type_node); 1668 1669 if (bits <= TYPE_PRECISION (intQI_type_node)) 1670 return unsignedp ? unsigned_intQI_type_node : intQI_type_node; 1671 1672 if (bits <= TYPE_PRECISION (intHI_type_node)) 1673 return unsignedp ? unsigned_intHI_type_node : intHI_type_node; 1674 1675 if (bits <= TYPE_PRECISION (intSI_type_node)) 1676 return unsignedp ? unsigned_intSI_type_node : intSI_type_node; 1677 1678 if (bits <= TYPE_PRECISION (intDI_type_node)) 1679 return unsignedp ? unsigned_intDI_type_node : intDI_type_node; 1680 1681 return 0; 1682} 1683 1684/* Used for communication between c_common_type_for_mode and 1685 c_register_builtin_type. */ 1686static GTY(()) tree registered_builtin_types; 1687 1688/* Return a data type that has machine mode MODE. 1689 If the mode is an integer, 1690 then UNSIGNEDP selects between signed and unsigned types. */ 1691 1692tree 1693c_common_type_for_mode (enum machine_mode mode, int unsignedp) 1694{ 1695 tree t; 1696 1697 if (mode == TYPE_MODE (integer_type_node)) 1698 return unsignedp ? unsigned_type_node : integer_type_node; 1699 1700 if (mode == TYPE_MODE (signed_char_type_node)) 1701 return unsignedp ? unsigned_char_type_node : signed_char_type_node; 1702 1703 if (mode == TYPE_MODE (short_integer_type_node)) 1704 return unsignedp ? short_unsigned_type_node : short_integer_type_node; 1705 1706 if (mode == TYPE_MODE (long_integer_type_node)) 1707 return unsignedp ? long_unsigned_type_node : long_integer_type_node; 1708 1709 if (mode == TYPE_MODE (long_long_integer_type_node)) 1710 return unsignedp ? long_long_unsigned_type_node : long_long_integer_type_node; 1711 1712 if (mode == TYPE_MODE (widest_integer_literal_type_node)) 1713 return unsignedp ? widest_unsigned_literal_type_node 1714 : widest_integer_literal_type_node; 1715 1716 if (mode == QImode) 1717 return unsignedp ? unsigned_intQI_type_node : intQI_type_node; 1718 1719 if (mode == HImode) 1720 return unsignedp ? unsigned_intHI_type_node : intHI_type_node; 1721 1722 if (mode == SImode) 1723 return unsignedp ? unsigned_intSI_type_node : intSI_type_node; 1724 1725 if (mode == DImode) 1726 return unsignedp ? unsigned_intDI_type_node : intDI_type_node; 1727 1728#if HOST_BITS_PER_WIDE_INT >= 64 1729 if (mode == TYPE_MODE (intTI_type_node)) 1730 return unsignedp ? unsigned_intTI_type_node : intTI_type_node; 1731#endif 1732 1733 if (mode == TYPE_MODE (float_type_node)) 1734 return float_type_node; 1735 1736 if (mode == TYPE_MODE (double_type_node)) 1737 return double_type_node; 1738 1739 if (mode == TYPE_MODE (long_double_type_node)) 1740 return long_double_type_node; 1741 1742 if (mode == TYPE_MODE (void_type_node)) 1743 return void_type_node; 1744 1745 if (mode == TYPE_MODE (build_pointer_type (char_type_node))) 1746 return (unsignedp 1747 ? make_unsigned_type (GET_MODE_PRECISION (mode)) 1748 : make_signed_type (GET_MODE_PRECISION (mode))); 1749 1750 if (mode == TYPE_MODE (build_pointer_type (integer_type_node))) 1751 return (unsignedp 1752 ? make_unsigned_type (GET_MODE_PRECISION (mode)) 1753 : make_signed_type (GET_MODE_PRECISION (mode))); 1754 1755 if (COMPLEX_MODE_P (mode)) 1756 { 1757 enum machine_mode inner_mode; 1758 tree inner_type; 1759 1760 if (mode == TYPE_MODE (complex_float_type_node)) 1761 return complex_float_type_node; 1762 if (mode == TYPE_MODE (complex_double_type_node)) 1763 return complex_double_type_node; 1764 if (mode == TYPE_MODE (complex_long_double_type_node)) 1765 return complex_long_double_type_node; 1766 1767 if (mode == TYPE_MODE (complex_integer_type_node) && !unsignedp) 1768 return complex_integer_type_node; 1769 1770 inner_mode = GET_MODE_INNER (mode); 1771 inner_type = c_common_type_for_mode (inner_mode, unsignedp); 1772 if (inner_type != NULL_TREE) 1773 return build_complex_type (inner_type); 1774 } 1775 else if (VECTOR_MODE_P (mode)) 1776 { 1777 enum machine_mode inner_mode = GET_MODE_INNER (mode); 1778 tree inner_type = c_common_type_for_mode (inner_mode, unsignedp); 1779 if (inner_type != NULL_TREE) 1780 return build_vector_type_for_mode (inner_type, mode); 1781 } 1782 1783 if (mode == TYPE_MODE (dfloat32_type_node)) 1784 return dfloat32_type_node; 1785 if (mode == TYPE_MODE (dfloat64_type_node)) 1786 return dfloat64_type_node; 1787 if (mode == TYPE_MODE (dfloat128_type_node)) 1788 return dfloat128_type_node; 1789 1790 for (t = registered_builtin_types; t; t = TREE_CHAIN (t)) 1791 if (TYPE_MODE (TREE_VALUE (t)) == mode) 1792 return TREE_VALUE (t); 1793 1794 return 0; 1795} 1796 1797/* Return an unsigned type the same as TYPE in other respects. */ 1798tree 1799c_common_unsigned_type (tree type) 1800{ 1801 tree type1 = TYPE_MAIN_VARIANT (type); 1802 if (type1 == signed_char_type_node || type1 == char_type_node) 1803 return unsigned_char_type_node; 1804 if (type1 == integer_type_node) 1805 return unsigned_type_node; 1806 if (type1 == short_integer_type_node) 1807 return short_unsigned_type_node; 1808 if (type1 == long_integer_type_node) 1809 return long_unsigned_type_node; 1810 if (type1 == long_long_integer_type_node) 1811 return long_long_unsigned_type_node; 1812 if (type1 == widest_integer_literal_type_node) 1813 return widest_unsigned_literal_type_node; 1814#if HOST_BITS_PER_WIDE_INT >= 64 1815 if (type1 == intTI_type_node) 1816 return unsigned_intTI_type_node; 1817#endif 1818 if (type1 == intDI_type_node) 1819 return unsigned_intDI_type_node; 1820 if (type1 == intSI_type_node) 1821 return unsigned_intSI_type_node; 1822 if (type1 == intHI_type_node) 1823 return unsigned_intHI_type_node; 1824 if (type1 == intQI_type_node) 1825 return unsigned_intQI_type_node; 1826 1827 return c_common_signed_or_unsigned_type (1, type); 1828} 1829 1830/* Return a signed type the same as TYPE in other respects. */ 1831 1832tree 1833c_common_signed_type (tree type) 1834{ 1835 tree type1 = TYPE_MAIN_VARIANT (type); 1836 if (type1 == unsigned_char_type_node || type1 == char_type_node) 1837 return signed_char_type_node; 1838 if (type1 == unsigned_type_node) 1839 return integer_type_node; 1840 if (type1 == short_unsigned_type_node) 1841 return short_integer_type_node; 1842 if (type1 == long_unsigned_type_node) 1843 return long_integer_type_node; 1844 if (type1 == long_long_unsigned_type_node) 1845 return long_long_integer_type_node; 1846 if (type1 == widest_unsigned_literal_type_node) 1847 return widest_integer_literal_type_node; 1848#if HOST_BITS_PER_WIDE_INT >= 64 1849 if (type1 == unsigned_intTI_type_node) 1850 return intTI_type_node; 1851#endif 1852 if (type1 == unsigned_intDI_type_node) 1853 return intDI_type_node; 1854 if (type1 == unsigned_intSI_type_node) 1855 return intSI_type_node; 1856 if (type1 == unsigned_intHI_type_node) 1857 return intHI_type_node; 1858 if (type1 == unsigned_intQI_type_node) 1859 return intQI_type_node; 1860 1861 return c_common_signed_or_unsigned_type (0, type); 1862} 1863 1864/* Return a type the same as TYPE except unsigned or 1865 signed according to UNSIGNEDP. */ 1866 1867tree 1868c_common_signed_or_unsigned_type (int unsignedp, tree type) 1869{ 1870 if (!INTEGRAL_TYPE_P (type) 1871 || TYPE_UNSIGNED (type) == unsignedp) 1872 return type; 1873 1874 /* For ENUMERAL_TYPEs in C++, must check the mode of the types, not 1875 the precision; they have precision set to match their range, but 1876 may use a wider mode to match an ABI. If we change modes, we may 1877 wind up with bad conversions. For INTEGER_TYPEs in C, must check 1878 the precision as well, so as to yield correct results for 1879 bit-field types. C++ does not have these separate bit-field 1880 types, and producing a signed or unsigned variant of an 1881 ENUMERAL_TYPE may cause other problems as well. */ 1882 1883#define TYPE_OK(node) \ 1884 (TYPE_MODE (type) == TYPE_MODE (node) \ 1885 && (c_dialect_cxx () || TYPE_PRECISION (type) == TYPE_PRECISION (node))) 1886 if (TYPE_OK (signed_char_type_node)) 1887 return unsignedp ? unsigned_char_type_node : signed_char_type_node; 1888 if (TYPE_OK (integer_type_node)) 1889 return unsignedp ? unsigned_type_node : integer_type_node; 1890 if (TYPE_OK (short_integer_type_node)) 1891 return unsignedp ? short_unsigned_type_node : short_integer_type_node; 1892 if (TYPE_OK (long_integer_type_node)) 1893 return unsignedp ? long_unsigned_type_node : long_integer_type_node; 1894 if (TYPE_OK (long_long_integer_type_node)) 1895 return (unsignedp ? long_long_unsigned_type_node 1896 : long_long_integer_type_node); 1897 if (TYPE_OK (widest_integer_literal_type_node)) 1898 return (unsignedp ? widest_unsigned_literal_type_node 1899 : widest_integer_literal_type_node); 1900 1901#if HOST_BITS_PER_WIDE_INT >= 64 1902 if (TYPE_OK (intTI_type_node)) 1903 return unsignedp ? unsigned_intTI_type_node : intTI_type_node; 1904#endif 1905 if (TYPE_OK (intDI_type_node)) 1906 return unsignedp ? unsigned_intDI_type_node : intDI_type_node; 1907 if (TYPE_OK (intSI_type_node)) 1908 return unsignedp ? unsigned_intSI_type_node : intSI_type_node; 1909 if (TYPE_OK (intHI_type_node)) 1910 return unsignedp ? unsigned_intHI_type_node : intHI_type_node; 1911 if (TYPE_OK (intQI_type_node)) 1912 return unsignedp ? unsigned_intQI_type_node : intQI_type_node; 1913#undef TYPE_OK 1914 1915 if (c_dialect_cxx ()) 1916 return type; 1917 else 1918 return build_nonstandard_integer_type (TYPE_PRECISION (type), unsignedp); 1919} 1920 1921/* Build a bit-field integer type for the given WIDTH and UNSIGNEDP. */ 1922 1923tree 1924c_build_bitfield_integer_type (unsigned HOST_WIDE_INT width, int unsignedp) 1925{ 1926 /* Extended integer types of the same width as a standard type have 1927 lesser rank, so those of the same width as int promote to int or 1928 unsigned int and are valid for printf formats expecting int or 1929 unsigned int. To avoid such special cases, avoid creating 1930 extended integer types for bit-fields if a standard integer type 1931 is available. */ 1932 if (width == TYPE_PRECISION (integer_type_node)) 1933 return unsignedp ? unsigned_type_node : integer_type_node; 1934 if (width == TYPE_PRECISION (signed_char_type_node)) 1935 return unsignedp ? unsigned_char_type_node : signed_char_type_node; 1936 if (width == TYPE_PRECISION (short_integer_type_node)) 1937 return unsignedp ? short_unsigned_type_node : short_integer_type_node; 1938 if (width == TYPE_PRECISION (long_integer_type_node)) 1939 return unsignedp ? long_unsigned_type_node : long_integer_type_node; 1940 if (width == TYPE_PRECISION (long_long_integer_type_node)) 1941 return (unsignedp ? long_long_unsigned_type_node 1942 : long_long_integer_type_node); 1943 return build_nonstandard_integer_type (width, unsignedp); 1944} 1945 1946/* The C version of the register_builtin_type langhook. */ 1947 1948void 1949c_register_builtin_type (tree type, const char* name) 1950{ 1951 tree decl; 1952 1953 decl = build_decl (TYPE_DECL, get_identifier (name), type); 1954 DECL_ARTIFICIAL (decl) = 1; 1955 if (!TYPE_NAME (type)) 1956 TYPE_NAME (type) = decl; 1957 pushdecl (decl); 1958 1959 registered_builtin_types = tree_cons (0, type, registered_builtin_types); 1960} 1961 1962 1963/* Return the minimum number of bits needed to represent VALUE in a 1964 signed or unsigned type, UNSIGNEDP says which. */ 1965 1966unsigned int 1967min_precision (tree value, int unsignedp) 1968{ 1969 int log; 1970 1971 /* If the value is negative, compute its negative minus 1. The latter 1972 adjustment is because the absolute value of the largest negative value 1973 is one larger than the largest positive value. This is equivalent to 1974 a bit-wise negation, so use that operation instead. */ 1975 1976 if (tree_int_cst_sgn (value) < 0) 1977 value = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (value), value); 1978 1979 /* Return the number of bits needed, taking into account the fact 1980 that we need one more bit for a signed than unsigned type. */ 1981 1982 if (integer_zerop (value)) 1983 log = 0; 1984 else 1985 log = tree_floor_log2 (value); 1986 1987 return log + 1 + !unsignedp; 1988} 1989 1990/* Print an error message for invalid operands to arith operation 1991 CODE with TYPE0 for operand 0, and TYPE1 for operand 1. */ 1992 1993void 1994binary_op_error (enum tree_code code, tree type0, tree type1) 1995{ 1996 const char *opname; 1997 1998 switch (code) 1999 { 2000 case PLUS_EXPR: 2001 opname = "+"; break; 2002 case MINUS_EXPR: 2003 opname = "-"; break; 2004 case MULT_EXPR: 2005 opname = "*"; break; 2006 case MAX_EXPR: 2007 opname = "max"; break; 2008 case MIN_EXPR: 2009 opname = "min"; break; 2010 case EQ_EXPR: 2011 opname = "=="; break; 2012 case NE_EXPR: 2013 opname = "!="; break; 2014 case LE_EXPR: 2015 opname = "<="; break; 2016 case GE_EXPR: 2017 opname = ">="; break; 2018 case LT_EXPR: 2019 opname = "<"; break; 2020 case GT_EXPR: 2021 opname = ">"; break; 2022 case LSHIFT_EXPR: 2023 opname = "<<"; break; 2024 case RSHIFT_EXPR: 2025 opname = ">>"; break; 2026 case TRUNC_MOD_EXPR: 2027 case FLOOR_MOD_EXPR: 2028 opname = "%"; break; 2029 case TRUNC_DIV_EXPR: 2030 case FLOOR_DIV_EXPR: 2031 opname = "/"; break; 2032 case BIT_AND_EXPR: 2033 opname = "&"; break; 2034 case BIT_IOR_EXPR: 2035 opname = "|"; break; 2036 case TRUTH_ANDIF_EXPR: 2037 opname = "&&"; break; 2038 case TRUTH_ORIF_EXPR: 2039 opname = "||"; break; 2040 case BIT_XOR_EXPR: 2041 opname = "^"; break; 2042 default: 2043 gcc_unreachable (); 2044 } 2045 error ("invalid operands to binary %s (have %qT and %qT)", opname, 2046 type0, type1); 2047} 2048 2049/* Subroutine of build_binary_op, used for comparison operations. 2050 See if the operands have both been converted from subword integer types 2051 and, if so, perhaps change them both back to their original type. 2052 This function is also responsible for converting the two operands 2053 to the proper common type for comparison. 2054 2055 The arguments of this function are all pointers to local variables 2056 of build_binary_op: OP0_PTR is &OP0, OP1_PTR is &OP1, 2057 RESTYPE_PTR is &RESULT_TYPE and RESCODE_PTR is &RESULTCODE. 2058 2059 If this function returns nonzero, it means that the comparison has 2060 a constant value. What this function returns is an expression for 2061 that value. */ 2062 2063tree 2064shorten_compare (tree *op0_ptr, tree *op1_ptr, tree *restype_ptr, 2065 enum tree_code *rescode_ptr) 2066{ 2067 tree type; 2068 tree op0 = *op0_ptr; 2069 tree op1 = *op1_ptr; 2070 int unsignedp0, unsignedp1; 2071 int real1, real2; 2072 tree primop0, primop1; 2073 enum tree_code code = *rescode_ptr; 2074 2075 /* Throw away any conversions to wider types 2076 already present in the operands. */ 2077 2078 primop0 = get_narrower (op0, &unsignedp0); 2079 primop1 = get_narrower (op1, &unsignedp1); 2080 2081 /* Handle the case that OP0 does not *contain* a conversion 2082 but it *requires* conversion to FINAL_TYPE. */ 2083 2084 if (op0 == primop0 && TREE_TYPE (op0) != *restype_ptr) 2085 unsignedp0 = TYPE_UNSIGNED (TREE_TYPE (op0)); 2086 if (op1 == primop1 && TREE_TYPE (op1) != *restype_ptr) 2087 unsignedp1 = TYPE_UNSIGNED (TREE_TYPE (op1)); 2088 2089 /* If one of the operands must be floated, we cannot optimize. */ 2090 real1 = TREE_CODE (TREE_TYPE (primop0)) == REAL_TYPE; 2091 real2 = TREE_CODE (TREE_TYPE (primop1)) == REAL_TYPE; 2092 2093 /* If first arg is constant, swap the args (changing operation 2094 so value is preserved), for canonicalization. Don't do this if 2095 the second arg is 0. */ 2096 2097 if (TREE_CONSTANT (primop0) 2098 && !integer_zerop (primop1) && !real_zerop (primop1)) 2099 { 2100 tree tem = primop0; 2101 int temi = unsignedp0; 2102 primop0 = primop1; 2103 primop1 = tem; 2104 tem = op0; 2105 op0 = op1; 2106 op1 = tem; 2107 *op0_ptr = op0; 2108 *op1_ptr = op1; 2109 unsignedp0 = unsignedp1; 2110 unsignedp1 = temi; 2111 temi = real1; 2112 real1 = real2; 2113 real2 = temi; 2114 2115 switch (code) 2116 { 2117 case LT_EXPR: 2118 code = GT_EXPR; 2119 break; 2120 case GT_EXPR: 2121 code = LT_EXPR; 2122 break; 2123 case LE_EXPR: 2124 code = GE_EXPR; 2125 break; 2126 case GE_EXPR: 2127 code = LE_EXPR; 2128 break; 2129 default: 2130 break; 2131 } 2132 *rescode_ptr = code; 2133 } 2134 2135 /* If comparing an integer against a constant more bits wide, 2136 maybe we can deduce a value of 1 or 0 independent of the data. 2137 Or else truncate the constant now 2138 rather than extend the variable at run time. 2139 2140 This is only interesting if the constant is the wider arg. 2141 Also, it is not safe if the constant is unsigned and the 2142 variable arg is signed, since in this case the variable 2143 would be sign-extended and then regarded as unsigned. 2144 Our technique fails in this case because the lowest/highest 2145 possible unsigned results don't follow naturally from the 2146 lowest/highest possible values of the variable operand. 2147 For just EQ_EXPR and NE_EXPR there is another technique that 2148 could be used: see if the constant can be faithfully represented 2149 in the other operand's type, by truncating it and reextending it 2150 and see if that preserves the constant's value. */ 2151 2152 if (!real1 && !real2 2153 && TREE_CODE (primop1) == INTEGER_CST 2154 && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr)) 2155 { 2156 int min_gt, max_gt, min_lt, max_lt; 2157 tree maxval, minval; 2158 /* 1 if comparison is nominally unsigned. */ 2159 int unsignedp = TYPE_UNSIGNED (*restype_ptr); 2160 tree val; 2161 2162 type = c_common_signed_or_unsigned_type (unsignedp0, 2163 TREE_TYPE (primop0)); 2164 2165 maxval = TYPE_MAX_VALUE (type); 2166 minval = TYPE_MIN_VALUE (type); 2167 2168 if (unsignedp && !unsignedp0) 2169 *restype_ptr = c_common_signed_type (*restype_ptr); 2170 2171 if (TREE_TYPE (primop1) != *restype_ptr) 2172 { 2173 /* Convert primop1 to target type, but do not introduce 2174 additional overflow. We know primop1 is an int_cst. */ 2175 tree tmp = build_int_cst_wide (*restype_ptr, 2176 TREE_INT_CST_LOW (primop1), 2177 TREE_INT_CST_HIGH (primop1)); 2178 2179 primop1 = force_fit_type (tmp, 0, TREE_OVERFLOW (primop1), 2180 TREE_CONSTANT_OVERFLOW (primop1)); 2181 } 2182 if (type != *restype_ptr) 2183 { 2184 minval = convert (*restype_ptr, minval); 2185 maxval = convert (*restype_ptr, maxval); 2186 } 2187 2188 if (unsignedp && unsignedp0) 2189 { 2190 min_gt = INT_CST_LT_UNSIGNED (primop1, minval); 2191 max_gt = INT_CST_LT_UNSIGNED (primop1, maxval); 2192 min_lt = INT_CST_LT_UNSIGNED (minval, primop1); 2193 max_lt = INT_CST_LT_UNSIGNED (maxval, primop1); 2194 } 2195 else 2196 { 2197 min_gt = INT_CST_LT (primop1, minval); 2198 max_gt = INT_CST_LT (primop1, maxval); 2199 min_lt = INT_CST_LT (minval, primop1); 2200 max_lt = INT_CST_LT (maxval, primop1); 2201 } 2202 2203 val = 0; 2204 /* This used to be a switch, but Genix compiler can't handle that. */ 2205 if (code == NE_EXPR) 2206 { 2207 if (max_lt || min_gt) 2208 val = truthvalue_true_node; 2209 } 2210 else if (code == EQ_EXPR) 2211 { 2212 if (max_lt || min_gt) 2213 val = truthvalue_false_node; 2214 } 2215 else if (code == LT_EXPR) 2216 { 2217 if (max_lt) 2218 val = truthvalue_true_node; 2219 if (!min_lt) 2220 val = truthvalue_false_node; 2221 } 2222 else if (code == GT_EXPR) 2223 { 2224 if (min_gt) 2225 val = truthvalue_true_node; 2226 if (!max_gt) 2227 val = truthvalue_false_node; 2228 } 2229 else if (code == LE_EXPR) 2230 { 2231 if (!max_gt) 2232 val = truthvalue_true_node; 2233 if (min_gt) 2234 val = truthvalue_false_node; 2235 } 2236 else if (code == GE_EXPR) 2237 { 2238 if (!min_lt) 2239 val = truthvalue_true_node; 2240 if (max_lt) 2241 val = truthvalue_false_node; 2242 } 2243 2244 /* If primop0 was sign-extended and unsigned comparison specd, 2245 we did a signed comparison above using the signed type bounds. 2246 But the comparison we output must be unsigned. 2247 2248 Also, for inequalities, VAL is no good; but if the signed 2249 comparison had *any* fixed result, it follows that the 2250 unsigned comparison just tests the sign in reverse 2251 (positive values are LE, negative ones GE). 2252 So we can generate an unsigned comparison 2253 against an extreme value of the signed type. */ 2254 2255 if (unsignedp && !unsignedp0) 2256 { 2257 if (val != 0) 2258 switch (code) 2259 { 2260 case LT_EXPR: 2261 case GE_EXPR: 2262 primop1 = TYPE_MIN_VALUE (type); 2263 val = 0; 2264 break; 2265 2266 case LE_EXPR: 2267 case GT_EXPR: 2268 primop1 = TYPE_MAX_VALUE (type); 2269 val = 0; 2270 break; 2271 2272 default: 2273 break; 2274 } 2275 type = c_common_unsigned_type (type); 2276 } 2277 2278 if (TREE_CODE (primop0) != INTEGER_CST) 2279 { 2280 if (val == truthvalue_false_node) 2281 warning (0, "comparison is always false due to limited range of data type"); 2282 if (val == truthvalue_true_node) 2283 warning (0, "comparison is always true due to limited range of data type"); 2284 } 2285 2286 if (val != 0) 2287 { 2288 /* Don't forget to evaluate PRIMOP0 if it has side effects. */ 2289 if (TREE_SIDE_EFFECTS (primop0)) 2290 return build2 (COMPOUND_EXPR, TREE_TYPE (val), primop0, val); 2291 return val; 2292 } 2293 2294 /* Value is not predetermined, but do the comparison 2295 in the type of the operand that is not constant. 2296 TYPE is already properly set. */ 2297 } 2298 2299 /* If either arg is decimal float and the other is float, find the 2300 proper common type to use for comparison. */ 2301 else if (real1 && real2 2302 && (DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (primop0))) 2303 || DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (primop1))))) 2304 type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1)); 2305 2306 else if (real1 && real2 2307 && (TYPE_PRECISION (TREE_TYPE (primop0)) 2308 == TYPE_PRECISION (TREE_TYPE (primop1)))) 2309 type = TREE_TYPE (primop0); 2310 2311 /* If args' natural types are both narrower than nominal type 2312 and both extend in the same manner, compare them 2313 in the type of the wider arg. 2314 Otherwise must actually extend both to the nominal 2315 common type lest different ways of extending 2316 alter the result. 2317 (eg, (short)-1 == (unsigned short)-1 should be 0.) */ 2318 2319 else if (unsignedp0 == unsignedp1 && real1 == real2 2320 && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr) 2321 && TYPE_PRECISION (TREE_TYPE (primop1)) < TYPE_PRECISION (*restype_ptr)) 2322 { 2323 type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1)); 2324 type = c_common_signed_or_unsigned_type (unsignedp0 2325 || TYPE_UNSIGNED (*restype_ptr), 2326 type); 2327 /* Make sure shorter operand is extended the right way 2328 to match the longer operand. */ 2329 primop0 2330 = convert (c_common_signed_or_unsigned_type (unsignedp0, 2331 TREE_TYPE (primop0)), 2332 primop0); 2333 primop1 2334 = convert (c_common_signed_or_unsigned_type (unsignedp1, 2335 TREE_TYPE (primop1)), 2336 primop1); 2337 } 2338 else 2339 { 2340 /* Here we must do the comparison on the nominal type 2341 using the args exactly as we received them. */ 2342 type = *restype_ptr; 2343 primop0 = op0; 2344 primop1 = op1; 2345 2346 if (!real1 && !real2 && integer_zerop (primop1) 2347 && TYPE_UNSIGNED (*restype_ptr)) 2348 { 2349 tree value = 0; 2350 switch (code) 2351 { 2352 case GE_EXPR: 2353 /* All unsigned values are >= 0, so we warn if extra warnings 2354 are requested. However, if OP0 is a constant that is 2355 >= 0, the signedness of the comparison isn't an issue, 2356 so suppress the warning. */ 2357 if (extra_warnings && !in_system_header 2358 && !(TREE_CODE (primop0) == INTEGER_CST 2359 && !TREE_OVERFLOW (convert (c_common_signed_type (type), 2360 primop0)))) 2361 warning (0, "comparison of unsigned expression >= 0 is always true"); 2362 value = truthvalue_true_node; 2363 break; 2364 2365 case LT_EXPR: 2366 if (extra_warnings && !in_system_header 2367 && !(TREE_CODE (primop0) == INTEGER_CST 2368 && !TREE_OVERFLOW (convert (c_common_signed_type (type), 2369 primop0)))) 2370 warning (0, "comparison of unsigned expression < 0 is always false"); 2371 value = truthvalue_false_node; 2372 break; 2373 2374 default: 2375 break; 2376 } 2377 2378 if (value != 0) 2379 { 2380 /* Don't forget to evaluate PRIMOP0 if it has side effects. */ 2381 if (TREE_SIDE_EFFECTS (primop0)) 2382 return build2 (COMPOUND_EXPR, TREE_TYPE (value), 2383 primop0, value); 2384 return value; 2385 } 2386 } 2387 } 2388 2389 *op0_ptr = convert (type, primop0); 2390 *op1_ptr = convert (type, primop1); 2391 2392 *restype_ptr = truthvalue_type_node; 2393 2394 return 0; 2395} 2396 2397/* Return a tree for the sum or difference (RESULTCODE says which) 2398 of pointer PTROP and integer INTOP. */ 2399 2400tree 2401pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop) 2402{ 2403 tree size_exp, ret; 2404 2405 /* The result is a pointer of the same type that is being added. */ 2406 2407 tree result_type = TREE_TYPE (ptrop); 2408 2409 if (TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE) 2410 { 2411 if (pedantic || warn_pointer_arith) 2412 pedwarn ("pointer of type %<void *%> used in arithmetic"); 2413 size_exp = integer_one_node; 2414 } 2415 else if (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE) 2416 { 2417 if (pedantic || warn_pointer_arith) 2418 pedwarn ("pointer to a function used in arithmetic"); 2419 size_exp = integer_one_node; 2420 } 2421 else if (TREE_CODE (TREE_TYPE (result_type)) == METHOD_TYPE) 2422 { 2423 if (pedantic || warn_pointer_arith) 2424 pedwarn ("pointer to member function used in arithmetic"); 2425 size_exp = integer_one_node; 2426 } 2427 else 2428 size_exp = size_in_bytes (TREE_TYPE (result_type)); 2429 2430 /* We are manipulating pointer values, so we don't need to warn 2431 about relying on undefined signed overflow. We disable the 2432 warning here because we use integer types so fold won't know that 2433 they are really pointers. */ 2434 fold_defer_overflow_warnings (); 2435 2436 /* If what we are about to multiply by the size of the elements 2437 contains a constant term, apply distributive law 2438 and multiply that constant term separately. 2439 This helps produce common subexpressions. */ 2440 2441 if ((TREE_CODE (intop) == PLUS_EXPR || TREE_CODE (intop) == MINUS_EXPR) 2442 && !TREE_CONSTANT (intop) 2443 && TREE_CONSTANT (TREE_OPERAND (intop, 1)) 2444 && TREE_CONSTANT (size_exp) 2445 /* If the constant comes from pointer subtraction, 2446 skip this optimization--it would cause an error. */ 2447 && TREE_CODE (TREE_TYPE (TREE_OPERAND (intop, 0))) == INTEGER_TYPE 2448 /* If the constant is unsigned, and smaller than the pointer size, 2449 then we must skip this optimization. This is because it could cause 2450 an overflow error if the constant is negative but INTOP is not. */ 2451 && (!TYPE_UNSIGNED (TREE_TYPE (intop)) 2452 || (TYPE_PRECISION (TREE_TYPE (intop)) 2453 == TYPE_PRECISION (TREE_TYPE (ptrop))))) 2454 { 2455 enum tree_code subcode = resultcode; 2456 tree int_type = TREE_TYPE (intop); 2457 if (TREE_CODE (intop) == MINUS_EXPR) 2458 subcode = (subcode == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR); 2459 /* Convert both subexpression types to the type of intop, 2460 because weird cases involving pointer arithmetic 2461 can result in a sum or difference with different type args. */ 2462 ptrop = build_binary_op (subcode, ptrop, 2463 convert (int_type, TREE_OPERAND (intop, 1)), 1); 2464 intop = convert (int_type, TREE_OPERAND (intop, 0)); 2465 } 2466 2467 /* Convert the integer argument to a type the same size as sizetype 2468 so the multiply won't overflow spuriously. */ 2469 2470 if (TYPE_PRECISION (TREE_TYPE (intop)) != TYPE_PRECISION (sizetype) 2471 || TYPE_UNSIGNED (TREE_TYPE (intop)) != TYPE_UNSIGNED (sizetype)) 2472 intop = convert (c_common_type_for_size (TYPE_PRECISION (sizetype), 2473 TYPE_UNSIGNED (sizetype)), intop); 2474 2475 /* Replace the integer argument with a suitable product by the object size. 2476 Do this multiplication as signed, then convert to the appropriate 2477 pointer type (actually unsigned integral). */ 2478 2479 intop = convert (result_type, 2480 build_binary_op (MULT_EXPR, intop, 2481 convert (TREE_TYPE (intop), size_exp), 1)); 2482 2483 /* Create the sum or difference. */ 2484 ret = fold_build2 (resultcode, result_type, ptrop, intop); 2485 2486 fold_undefer_and_ignore_overflow_warnings (); 2487 2488 return ret; 2489} 2490 2491/* Prepare expr to be an argument of a TRUTH_NOT_EXPR, 2492 or for an `if' or `while' statement or ?..: exp. It should already 2493 have been validated to be of suitable type; otherwise, a bad 2494 diagnostic may result. 2495 2496 This preparation consists of taking the ordinary 2497 representation of an expression expr and producing a valid tree 2498 boolean expression describing whether expr is nonzero. We could 2499 simply always do build_binary_op (NE_EXPR, expr, truthvalue_false_node, 1), 2500 but we optimize comparisons, &&, ||, and !. 2501 2502 The resulting type should always be `truthvalue_type_node'. */ 2503 2504tree 2505c_common_truthvalue_conversion (tree expr) 2506{ 2507 switch (TREE_CODE (expr)) 2508 { 2509 case EQ_EXPR: case NE_EXPR: case UNEQ_EXPR: case LTGT_EXPR: 2510 case LE_EXPR: case GE_EXPR: case LT_EXPR: case GT_EXPR: 2511 case UNLE_EXPR: case UNGE_EXPR: case UNLT_EXPR: case UNGT_EXPR: 2512 case ORDERED_EXPR: case UNORDERED_EXPR: 2513 if (TREE_TYPE (expr) == truthvalue_type_node) 2514 return expr; 2515 return build2 (TREE_CODE (expr), truthvalue_type_node, 2516 TREE_OPERAND (expr, 0), TREE_OPERAND (expr, 1)); 2517 2518 case TRUTH_ANDIF_EXPR: 2519 case TRUTH_ORIF_EXPR: 2520 case TRUTH_AND_EXPR: 2521 case TRUTH_OR_EXPR: 2522 case TRUTH_XOR_EXPR: 2523 if (TREE_TYPE (expr) == truthvalue_type_node) 2524 return expr; 2525 return build2 (TREE_CODE (expr), truthvalue_type_node, 2526 c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)), 2527 c_common_truthvalue_conversion (TREE_OPERAND (expr, 1))); 2528 2529 case TRUTH_NOT_EXPR: 2530 if (TREE_TYPE (expr) == truthvalue_type_node) 2531 return expr; 2532 return build1 (TREE_CODE (expr), truthvalue_type_node, 2533 c_common_truthvalue_conversion (TREE_OPERAND (expr, 0))); 2534 2535 case ERROR_MARK: 2536 return expr; 2537 2538 case INTEGER_CST: 2539 /* Avoid integer_zerop to ignore TREE_CONSTANT_OVERFLOW. */ 2540 return (TREE_INT_CST_LOW (expr) != 0 || TREE_INT_CST_HIGH (expr) != 0) 2541 ? truthvalue_true_node 2542 : truthvalue_false_node; 2543 2544 case REAL_CST: 2545 return real_compare (NE_EXPR, &TREE_REAL_CST (expr), &dconst0) 2546 ? truthvalue_true_node 2547 : truthvalue_false_node; 2548 2549 case FUNCTION_DECL: 2550 expr = build_unary_op (ADDR_EXPR, expr, 0); 2551 /* Fall through. */ 2552 2553 case ADDR_EXPR: 2554 { 2555 tree inner = TREE_OPERAND (expr, 0); 2556 if (DECL_P (inner) 2557 && (TREE_CODE (inner) == PARM_DECL 2558 || TREE_CODE (inner) == LABEL_DECL 2559 || !DECL_WEAK (inner))) 2560 { 2561 /* Common Ada/Pascal programmer's mistake. We always warn 2562 about this since it is so bad. */ 2563 warning (OPT_Waddress, 2564 "the address of %qD will always evaluate as %<true%>", 2565 inner); 2566 return truthvalue_true_node; 2567 } 2568 2569 /* If we are taking the address of an external decl, it might be 2570 zero if it is weak, so we cannot optimize. */ 2571 if (DECL_P (inner) 2572 && DECL_EXTERNAL (inner)) 2573 break; 2574 2575 if (TREE_SIDE_EFFECTS (inner)) 2576 return build2 (COMPOUND_EXPR, truthvalue_type_node, 2577 inner, truthvalue_true_node); 2578 else 2579 return truthvalue_true_node; 2580 } 2581 2582 case COMPLEX_EXPR: 2583 return build_binary_op ((TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)) 2584 ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR), 2585 c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)), 2586 c_common_truthvalue_conversion (TREE_OPERAND (expr, 1)), 2587 0); 2588 2589 case NEGATE_EXPR: 2590 case ABS_EXPR: 2591 case FLOAT_EXPR: 2592 /* These don't change whether an object is nonzero or zero. */ 2593 return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)); 2594 2595 case LROTATE_EXPR: 2596 case RROTATE_EXPR: 2597 /* These don't change whether an object is zero or nonzero, but 2598 we can't ignore them if their second arg has side-effects. */ 2599 if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1))) 2600 return build2 (COMPOUND_EXPR, truthvalue_type_node, 2601 TREE_OPERAND (expr, 1), 2602 c_common_truthvalue_conversion (TREE_OPERAND (expr, 0))); 2603 else 2604 return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)); 2605 2606 case COND_EXPR: 2607 /* Distribute the conversion into the arms of a COND_EXPR. */ 2608 return fold_build3 (COND_EXPR, truthvalue_type_node, 2609 TREE_OPERAND (expr, 0), 2610 c_common_truthvalue_conversion (TREE_OPERAND (expr, 1)), 2611 c_common_truthvalue_conversion (TREE_OPERAND (expr, 2))); 2612 2613 case CONVERT_EXPR: 2614 case NOP_EXPR: 2615 /* Don't cancel the effect of a CONVERT_EXPR from a REFERENCE_TYPE, 2616 since that affects how `default_conversion' will behave. */ 2617 if (TREE_CODE (TREE_TYPE (expr)) == REFERENCE_TYPE 2618 || TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == REFERENCE_TYPE) 2619 break; 2620 /* If this is widening the argument, we can ignore it. */ 2621 if (TYPE_PRECISION (TREE_TYPE (expr)) 2622 >= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (expr, 0)))) 2623 return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)); 2624 break; 2625 2626 case MODIFY_EXPR: 2627 if (!TREE_NO_WARNING (expr) 2628 && warn_parentheses) 2629 { 2630 warning (OPT_Wparentheses, 2631 "suggest parentheses around assignment used as truth value"); 2632 TREE_NO_WARNING (expr) = 1; 2633 } 2634 break; 2635 2636 default: 2637 break; 2638 } 2639 2640 if (TREE_CODE (TREE_TYPE (expr)) == COMPLEX_TYPE) 2641 { 2642 tree t = save_expr (expr); 2643 return (build_binary_op 2644 ((TREE_SIDE_EFFECTS (expr) 2645 ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR), 2646 c_common_truthvalue_conversion (build_unary_op (REALPART_EXPR, t, 0)), 2647 c_common_truthvalue_conversion (build_unary_op (IMAGPART_EXPR, t, 0)), 2648 0)); 2649 } 2650 2651 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1); 2652} 2653 2654static void def_builtin_1 (enum built_in_function fncode, 2655 const char *name, 2656 enum built_in_class fnclass, 2657 tree fntype, tree libtype, 2658 bool both_p, bool fallback_p, bool nonansi_p, 2659 tree fnattrs, bool implicit_p); 2660 2661/* Make a variant type in the proper way for C/C++, propagating qualifiers 2662 down to the element type of an array. */ 2663 2664tree 2665c_build_qualified_type (tree type, int type_quals) 2666{ 2667 if (type == error_mark_node) 2668 return type; 2669 2670 if (TREE_CODE (type) == ARRAY_TYPE) 2671 { 2672 tree t; 2673 tree element_type = c_build_qualified_type (TREE_TYPE (type), 2674 type_quals); 2675 2676 /* See if we already have an identically qualified type. */ 2677 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t)) 2678 { 2679 if (TYPE_QUALS (strip_array_types (t)) == type_quals 2680 && TYPE_NAME (t) == TYPE_NAME (type) 2681 && TYPE_CONTEXT (t) == TYPE_CONTEXT (type) 2682 && attribute_list_equal (TYPE_ATTRIBUTES (t), 2683 TYPE_ATTRIBUTES (type))) 2684 break; 2685 } 2686 if (!t) 2687 { 2688 t = build_variant_type_copy (type); 2689 TREE_TYPE (t) = element_type; 2690 } 2691 return t; 2692 } 2693 2694 /* A restrict-qualified pointer type must be a pointer to object or 2695 incomplete type. Note that the use of POINTER_TYPE_P also allows 2696 REFERENCE_TYPEs, which is appropriate for C++. */ 2697 if ((type_quals & TYPE_QUAL_RESTRICT) 2698 && (!POINTER_TYPE_P (type) 2699 || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (type)))) 2700 { 2701 error ("invalid use of %<restrict%>"); 2702 type_quals &= ~TYPE_QUAL_RESTRICT; 2703 } 2704 2705 return build_qualified_type (type, type_quals); 2706} 2707 2708/* Apply the TYPE_QUALS to the new DECL. */ 2709 2710void 2711c_apply_type_quals_to_decl (int type_quals, tree decl) 2712{ 2713 tree type = TREE_TYPE (decl); 2714 2715 if (type == error_mark_node) 2716 return; 2717 2718 if (((type_quals & TYPE_QUAL_CONST) 2719 || (type && TREE_CODE (type) == REFERENCE_TYPE)) 2720 /* An object declared 'const' is only readonly after it is 2721 initialized. We don't have any way of expressing this currently, 2722 so we need to be conservative and unset TREE_READONLY for types 2723 with constructors. Otherwise aliasing code will ignore stores in 2724 an inline constructor. */ 2725 && !(type && TYPE_NEEDS_CONSTRUCTING (type))) 2726 TREE_READONLY (decl) = 1; 2727 if (type_quals & TYPE_QUAL_VOLATILE) 2728 { 2729 TREE_SIDE_EFFECTS (decl) = 1; 2730 TREE_THIS_VOLATILE (decl) = 1; 2731 } 2732 if (type_quals & TYPE_QUAL_RESTRICT) 2733 { 2734 while (type && TREE_CODE (type) == ARRAY_TYPE) 2735 /* Allow 'restrict' on arrays of pointers. 2736 FIXME currently we just ignore it. */ 2737 type = TREE_TYPE (type); 2738 if (!type 2739 || !POINTER_TYPE_P (type) 2740 || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (type))) 2741 error ("invalid use of %<restrict%>"); 2742 else if (flag_strict_aliasing && type == TREE_TYPE (decl)) 2743 /* Indicate we need to make a unique alias set for this pointer. 2744 We can't do it here because it might be pointing to an 2745 incomplete type. */ 2746 DECL_POINTER_ALIAS_SET (decl) = -2; 2747 } 2748} 2749 2750/* Hash function for the problem of multiple type definitions in 2751 different files. This must hash all types that will compare 2752 equal via comptypes to the same value. In practice it hashes 2753 on some of the simple stuff and leaves the details to comptypes. */ 2754 2755static hashval_t 2756c_type_hash (const void *p) 2757{ 2758 int i = 0; 2759 int shift, size; 2760 tree t = (tree) p; 2761 tree t2; 2762 switch (TREE_CODE (t)) 2763 { 2764 /* For pointers, hash on pointee type plus some swizzling. */ 2765 case POINTER_TYPE: 2766 return c_type_hash (TREE_TYPE (t)) ^ 0x3003003; 2767 /* Hash on number of elements and total size. */ 2768 case ENUMERAL_TYPE: 2769 shift = 3; 2770 t2 = TYPE_VALUES (t); 2771 break; 2772 case RECORD_TYPE: 2773 shift = 0; 2774 t2 = TYPE_FIELDS (t); 2775 break; 2776 case QUAL_UNION_TYPE: 2777 shift = 1; 2778 t2 = TYPE_FIELDS (t); 2779 break; 2780 case UNION_TYPE: 2781 shift = 2; 2782 t2 = TYPE_FIELDS (t); 2783 break; 2784 default: 2785 gcc_unreachable (); 2786 } 2787 for (; t2; t2 = TREE_CHAIN (t2)) 2788 i++; 2789 size = TREE_INT_CST_LOW (TYPE_SIZE (t)); 2790 return ((size << 24) | (i << shift)); 2791} 2792 2793static GTY((param_is (union tree_node))) htab_t type_hash_table; 2794 2795/* Return the typed-based alias set for T, which may be an expression 2796 or a type. Return -1 if we don't do anything special. */ 2797 2798HOST_WIDE_INT 2799c_common_get_alias_set (tree t) 2800{ 2801 tree u; 2802 PTR *slot; 2803 2804 /* Permit type-punning when accessing a union, provided the access 2805 is directly through the union. For example, this code does not 2806 permit taking the address of a union member and then storing 2807 through it. Even the type-punning allowed here is a GCC 2808 extension, albeit a common and useful one; the C standard says 2809 that such accesses have implementation-defined behavior. */ 2810 for (u = t; 2811 TREE_CODE (u) == COMPONENT_REF || TREE_CODE (u) == ARRAY_REF; 2812 u = TREE_OPERAND (u, 0)) 2813 if (TREE_CODE (u) == COMPONENT_REF 2814 && TREE_CODE (TREE_TYPE (TREE_OPERAND (u, 0))) == UNION_TYPE) 2815 return 0; 2816 2817 /* That's all the expressions we handle specially. */ 2818 if (!TYPE_P (t)) 2819 return -1; 2820 2821 /* The C standard guarantees that any object may be accessed via an 2822 lvalue that has character type. */ 2823 if (t == char_type_node 2824 || t == signed_char_type_node 2825 || t == unsigned_char_type_node) 2826 return 0; 2827 2828 /* If it has the may_alias attribute, it can alias anything. */ 2829 if (lookup_attribute ("may_alias", TYPE_ATTRIBUTES (t))) 2830 return 0; 2831 2832 /* The C standard specifically allows aliasing between signed and 2833 unsigned variants of the same type. We treat the signed 2834 variant as canonical. */ 2835 if (TREE_CODE (t) == INTEGER_TYPE && TYPE_UNSIGNED (t)) 2836 { 2837 tree t1 = c_common_signed_type (t); 2838 2839 /* t1 == t can happen for boolean nodes which are always unsigned. */ 2840 if (t1 != t) 2841 return get_alias_set (t1); 2842 } 2843 else if (POINTER_TYPE_P (t)) 2844 { 2845 tree t1; 2846 2847 /* Unfortunately, there is no canonical form of a pointer type. 2848 In particular, if we have `typedef int I', then `int *', and 2849 `I *' are different types. So, we have to pick a canonical 2850 representative. We do this below. 2851 2852 Technically, this approach is actually more conservative that 2853 it needs to be. In particular, `const int *' and `int *' 2854 should be in different alias sets, according to the C and C++ 2855 standard, since their types are not the same, and so, 2856 technically, an `int **' and `const int **' cannot point at 2857 the same thing. 2858 2859 But, the standard is wrong. In particular, this code is 2860 legal C++: 2861 2862 int *ip; 2863 int **ipp = &ip; 2864 const int* const* cipp = ipp; 2865 2866 And, it doesn't make sense for that to be legal unless you 2867 can dereference IPP and CIPP. So, we ignore cv-qualifiers on 2868 the pointed-to types. This issue has been reported to the 2869 C++ committee. */ 2870 t1 = build_type_no_quals (t); 2871 if (t1 != t) 2872 return get_alias_set (t1); 2873 } 2874 2875 /* Handle the case of multiple type nodes referring to "the same" type, 2876 which occurs with IMA. These share an alias set. FIXME: Currently only 2877 C90 is handled. (In C99 type compatibility is not transitive, which 2878 complicates things mightily. The alias set splay trees can theoretically 2879 represent this, but insertion is tricky when you consider all the 2880 different orders things might arrive in.) */ 2881 2882 if (c_language != clk_c || flag_isoc99) 2883 return -1; 2884 2885 /* Save time if there's only one input file. */ 2886 if (num_in_fnames == 1) 2887 return -1; 2888 2889 /* Pointers need special handling if they point to any type that 2890 needs special handling (below). */ 2891 if (TREE_CODE (t) == POINTER_TYPE) 2892 { 2893 tree t2; 2894 /* Find bottom type under any nested POINTERs. */ 2895 for (t2 = TREE_TYPE (t); 2896 TREE_CODE (t2) == POINTER_TYPE; 2897 t2 = TREE_TYPE (t2)) 2898 ; 2899 if (TREE_CODE (t2) != RECORD_TYPE 2900 && TREE_CODE (t2) != ENUMERAL_TYPE 2901 && TREE_CODE (t2) != QUAL_UNION_TYPE 2902 && TREE_CODE (t2) != UNION_TYPE) 2903 return -1; 2904 if (TYPE_SIZE (t2) == 0) 2905 return -1; 2906 } 2907 /* These are the only cases that need special handling. */ 2908 if (TREE_CODE (t) != RECORD_TYPE 2909 && TREE_CODE (t) != ENUMERAL_TYPE 2910 && TREE_CODE (t) != QUAL_UNION_TYPE 2911 && TREE_CODE (t) != UNION_TYPE 2912 && TREE_CODE (t) != POINTER_TYPE) 2913 return -1; 2914 /* Undefined? */ 2915 if (TYPE_SIZE (t) == 0) 2916 return -1; 2917 2918 /* Look up t in hash table. Only one of the compatible types within each 2919 alias set is recorded in the table. */ 2920 if (!type_hash_table) 2921 type_hash_table = htab_create_ggc (1021, c_type_hash, 2922 (htab_eq) lang_hooks.types_compatible_p, 2923 NULL); 2924 slot = htab_find_slot (type_hash_table, t, INSERT); 2925 if (*slot != NULL) 2926 { 2927 TYPE_ALIAS_SET (t) = TYPE_ALIAS_SET ((tree)*slot); 2928 return TYPE_ALIAS_SET ((tree)*slot); 2929 } 2930 else 2931 /* Our caller will assign and record (in t) a new alias set; all we need 2932 to do is remember t in the hash table. */ 2933 *slot = t; 2934 2935 return -1; 2936} 2937 2938/* Compute the value of 'sizeof (TYPE)' or '__alignof__ (TYPE)', where the 2939 second parameter indicates which OPERATOR is being applied. The COMPLAIN 2940 flag controls whether we should diagnose possibly ill-formed 2941 constructs or not. */ 2942 2943tree 2944c_sizeof_or_alignof_type (tree type, bool is_sizeof, int complain) 2945{ 2946 const char *op_name; 2947 tree value = NULL; 2948 enum tree_code type_code = TREE_CODE (type); 2949 2950 op_name = is_sizeof ? "sizeof" : "__alignof__"; 2951 2952 if (type_code == FUNCTION_TYPE) 2953 { 2954 if (is_sizeof) 2955 { 2956 if (complain && (pedantic || warn_pointer_arith)) 2957 pedwarn ("invalid application of %<sizeof%> to a function type"); 2958 value = size_one_node; 2959 } 2960 else 2961 value = size_int (FUNCTION_BOUNDARY / BITS_PER_UNIT); 2962 } 2963 else if (type_code == VOID_TYPE || type_code == ERROR_MARK) 2964 { 2965 if (type_code == VOID_TYPE 2966 && complain && (pedantic || warn_pointer_arith)) 2967 pedwarn ("invalid application of %qs to a void type", op_name); 2968 value = size_one_node; 2969 } 2970 else if (!COMPLETE_TYPE_P (type)) 2971 { 2972 if (complain) 2973 error ("invalid application of %qs to incomplete type %qT ", 2974 op_name, type); 2975 value = size_zero_node; 2976 } 2977 else 2978 { 2979 if (is_sizeof) 2980 /* Convert in case a char is more than one unit. */ 2981 value = size_binop (CEIL_DIV_EXPR, TYPE_SIZE_UNIT (type), 2982 size_int (TYPE_PRECISION (char_type_node) 2983 / BITS_PER_UNIT)); 2984 else 2985 value = size_int (TYPE_ALIGN_UNIT (type)); 2986 } 2987 2988 /* VALUE will have an integer type with TYPE_IS_SIZETYPE set. 2989 TYPE_IS_SIZETYPE means that certain things (like overflow) will 2990 never happen. However, this node should really have type 2991 `size_t', which is just a typedef for an ordinary integer type. */ 2992 value = fold_convert (size_type_node, value); 2993 gcc_assert (!TYPE_IS_SIZETYPE (TREE_TYPE (value))); 2994 2995 return value; 2996} 2997 2998/* Implement the __alignof keyword: Return the minimum required 2999 alignment of EXPR, measured in bytes. For VAR_DECLs, 3000 FUNCTION_DECLs and FIELD_DECLs return DECL_ALIGN (which can be set 3001 from an "aligned" __attribute__ specification). */ 3002 3003tree 3004c_alignof_expr (tree expr) 3005{ 3006 tree t; 3007 3008 if (VAR_OR_FUNCTION_DECL_P (expr)) 3009 t = size_int (DECL_ALIGN_UNIT (expr)); 3010 3011 else if (TREE_CODE (expr) == COMPONENT_REF 3012 && DECL_C_BIT_FIELD (TREE_OPERAND (expr, 1))) 3013 { 3014 error ("%<__alignof%> applied to a bit-field"); 3015 t = size_one_node; 3016 } 3017 else if (TREE_CODE (expr) == COMPONENT_REF 3018 && TREE_CODE (TREE_OPERAND (expr, 1)) == FIELD_DECL) 3019 t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (expr, 1))); 3020 3021 else if (TREE_CODE (expr) == INDIRECT_REF) 3022 { 3023 tree t = TREE_OPERAND (expr, 0); 3024 tree best = t; 3025 int bestalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t))); 3026 3027 while ((TREE_CODE (t) == NOP_EXPR || TREE_CODE (t) == CONVERT_EXPR) 3028 && TREE_CODE (TREE_TYPE (TREE_OPERAND (t, 0))) == POINTER_TYPE) 3029 { 3030 int thisalign; 3031 3032 t = TREE_OPERAND (t, 0); 3033 thisalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t))); 3034 if (thisalign > bestalign) 3035 best = t, bestalign = thisalign; 3036 } 3037 return c_alignof (TREE_TYPE (TREE_TYPE (best))); 3038 } 3039 else 3040 return c_alignof (TREE_TYPE (expr)); 3041 3042 return fold_convert (size_type_node, t); 3043} 3044 3045/* Handle C and C++ default attributes. */ 3046 3047enum built_in_attribute 3048{ 3049#define DEF_ATTR_NULL_TREE(ENUM) ENUM, 3050#define DEF_ATTR_INT(ENUM, VALUE) ENUM, 3051#define DEF_ATTR_IDENT(ENUM, STRING) ENUM, 3052#define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) ENUM, 3053#include "builtin-attrs.def" 3054#undef DEF_ATTR_NULL_TREE 3055#undef DEF_ATTR_INT 3056#undef DEF_ATTR_IDENT 3057#undef DEF_ATTR_TREE_LIST 3058 ATTR_LAST 3059}; 3060 3061static GTY(()) tree built_in_attributes[(int) ATTR_LAST]; 3062 3063static void c_init_attributes (void); 3064 3065enum c_builtin_type 3066{ 3067#define DEF_PRIMITIVE_TYPE(NAME, VALUE) NAME, 3068#define DEF_FUNCTION_TYPE_0(NAME, RETURN) NAME, 3069#define DEF_FUNCTION_TYPE_1(NAME, RETURN, ARG1) NAME, 3070#define DEF_FUNCTION_TYPE_2(NAME, RETURN, ARG1, ARG2) NAME, 3071#define DEF_FUNCTION_TYPE_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME, 3072#define DEF_FUNCTION_TYPE_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME, 3073#define DEF_FUNCTION_TYPE_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) NAME, 3074#define DEF_FUNCTION_TYPE_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6) NAME, 3075#define DEF_FUNCTION_TYPE_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7) NAME, 3076#define DEF_FUNCTION_TYPE_VAR_0(NAME, RETURN) NAME, 3077#define DEF_FUNCTION_TYPE_VAR_1(NAME, RETURN, ARG1) NAME, 3078#define DEF_FUNCTION_TYPE_VAR_2(NAME, RETURN, ARG1, ARG2) NAME, 3079#define DEF_FUNCTION_TYPE_VAR_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME, 3080#define DEF_FUNCTION_TYPE_VAR_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME, 3081#define DEF_FUNCTION_TYPE_VAR_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG6) \ 3082 NAME, 3083#define DEF_POINTER_TYPE(NAME, TYPE) NAME, 3084#include "builtin-types.def" 3085#undef DEF_PRIMITIVE_TYPE 3086#undef DEF_FUNCTION_TYPE_0 3087#undef DEF_FUNCTION_TYPE_1 3088#undef DEF_FUNCTION_TYPE_2 3089#undef DEF_FUNCTION_TYPE_3 3090#undef DEF_FUNCTION_TYPE_4 3091#undef DEF_FUNCTION_TYPE_5 3092#undef DEF_FUNCTION_TYPE_6 3093#undef DEF_FUNCTION_TYPE_7 3094#undef DEF_FUNCTION_TYPE_VAR_0 3095#undef DEF_FUNCTION_TYPE_VAR_1 3096#undef DEF_FUNCTION_TYPE_VAR_2 3097#undef DEF_FUNCTION_TYPE_VAR_3 3098#undef DEF_FUNCTION_TYPE_VAR_4 3099#undef DEF_FUNCTION_TYPE_VAR_5 3100#undef DEF_POINTER_TYPE 3101 BT_LAST 3102}; 3103 3104typedef enum c_builtin_type builtin_type; 3105 3106/* A temporary array for c_common_nodes_and_builtins. Used in 3107 communication with def_fn_type. */ 3108static tree builtin_types[(int) BT_LAST + 1]; 3109 3110/* A helper function for c_common_nodes_and_builtins. Build function type 3111 for DEF with return type RET and N arguments. If VAR is true, then the 3112 function should be variadic after those N arguments. 3113 3114 Takes special care not to ICE if any of the types involved are 3115 error_mark_node, which indicates that said type is not in fact available 3116 (see builtin_type_for_size). In which case the function type as a whole 3117 should be error_mark_node. */ 3118 3119static void 3120def_fn_type (builtin_type def, builtin_type ret, bool var, int n, ...) 3121{ 3122 tree args = NULL, t; 3123 va_list list; 3124 int i; 3125 3126 va_start (list, n); 3127 for (i = 0; i < n; ++i) 3128 { 3129 builtin_type a = va_arg (list, builtin_type); 3130 t = builtin_types[a]; 3131 if (t == error_mark_node) 3132 goto egress; 3133 args = tree_cons (NULL_TREE, t, args); 3134 } 3135 va_end (list); 3136 3137 args = nreverse (args); 3138 if (!var) 3139 args = chainon (args, void_list_node); 3140 3141 t = builtin_types[ret]; 3142 if (t == error_mark_node) 3143 goto egress; 3144 t = build_function_type (t, args); 3145 3146 egress: 3147 builtin_types[def] = t; 3148} 3149 3150/* Build builtin functions common to both C and C++ language 3151 frontends. */ 3152 3153static void 3154c_define_builtins (tree va_list_ref_type_node, tree va_list_arg_type_node) 3155{ 3156#define DEF_PRIMITIVE_TYPE(ENUM, VALUE) \ 3157 builtin_types[ENUM] = VALUE; 3158#define DEF_FUNCTION_TYPE_0(ENUM, RETURN) \ 3159 def_fn_type (ENUM, RETURN, 0, 0); 3160#define DEF_FUNCTION_TYPE_1(ENUM, RETURN, ARG1) \ 3161 def_fn_type (ENUM, RETURN, 0, 1, ARG1); 3162#define DEF_FUNCTION_TYPE_2(ENUM, RETURN, ARG1, ARG2) \ 3163 def_fn_type (ENUM, RETURN, 0, 2, ARG1, ARG2); 3164#define DEF_FUNCTION_TYPE_3(ENUM, RETURN, ARG1, ARG2, ARG3) \ 3165 def_fn_type (ENUM, RETURN, 0, 3, ARG1, ARG2, ARG3); 3166#define DEF_FUNCTION_TYPE_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \ 3167 def_fn_type (ENUM, RETURN, 0, 4, ARG1, ARG2, ARG3, ARG4); 3168#define DEF_FUNCTION_TYPE_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \ 3169 def_fn_type (ENUM, RETURN, 0, 5, ARG1, ARG2, ARG3, ARG4, ARG5); 3170#define DEF_FUNCTION_TYPE_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \ 3171 ARG6) \ 3172 def_fn_type (ENUM, RETURN, 0, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6); 3173#define DEF_FUNCTION_TYPE_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \ 3174 ARG6, ARG7) \ 3175 def_fn_type (ENUM, RETURN, 0, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7); 3176#define DEF_FUNCTION_TYPE_VAR_0(ENUM, RETURN) \ 3177 def_fn_type (ENUM, RETURN, 1, 0); 3178#define DEF_FUNCTION_TYPE_VAR_1(ENUM, RETURN, ARG1) \ 3179 def_fn_type (ENUM, RETURN, 1, 1, ARG1); 3180#define DEF_FUNCTION_TYPE_VAR_2(ENUM, RETURN, ARG1, ARG2) \ 3181 def_fn_type (ENUM, RETURN, 1, 2, ARG1, ARG2); 3182#define DEF_FUNCTION_TYPE_VAR_3(ENUM, RETURN, ARG1, ARG2, ARG3) \ 3183 def_fn_type (ENUM, RETURN, 1, 3, ARG1, ARG2, ARG3); 3184#define DEF_FUNCTION_TYPE_VAR_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \ 3185 def_fn_type (ENUM, RETURN, 1, 4, ARG1, ARG2, ARG3, ARG4); 3186#define DEF_FUNCTION_TYPE_VAR_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \ 3187 def_fn_type (ENUM, RETURN, 1, 5, ARG1, ARG2, ARG3, ARG4, ARG5); 3188#define DEF_POINTER_TYPE(ENUM, TYPE) \ 3189 builtin_types[(int) ENUM] = build_pointer_type (builtin_types[(int) TYPE]); 3190 3191#include "builtin-types.def" 3192 3193#undef DEF_PRIMITIVE_TYPE 3194#undef DEF_FUNCTION_TYPE_1 3195#undef DEF_FUNCTION_TYPE_2 3196#undef DEF_FUNCTION_TYPE_3 3197#undef DEF_FUNCTION_TYPE_4 3198#undef DEF_FUNCTION_TYPE_5 3199#undef DEF_FUNCTION_TYPE_6 3200#undef DEF_FUNCTION_TYPE_VAR_0 3201#undef DEF_FUNCTION_TYPE_VAR_1 3202#undef DEF_FUNCTION_TYPE_VAR_2 3203#undef DEF_FUNCTION_TYPE_VAR_3 3204#undef DEF_FUNCTION_TYPE_VAR_4 3205#undef DEF_FUNCTION_TYPE_VAR_5 3206#undef DEF_POINTER_TYPE 3207 builtin_types[(int) BT_LAST] = NULL_TREE; 3208 3209 c_init_attributes (); 3210 3211#define DEF_BUILTIN(ENUM, NAME, CLASS, TYPE, LIBTYPE, BOTH_P, FALLBACK_P, \ 3212 NONANSI_P, ATTRS, IMPLICIT, COND) \ 3213 if (NAME && COND) \ 3214 def_builtin_1 (ENUM, NAME, CLASS, \ 3215 builtin_types[(int) TYPE], \ 3216 builtin_types[(int) LIBTYPE], \ 3217 BOTH_P, FALLBACK_P, NONANSI_P, \ 3218 built_in_attributes[(int) ATTRS], IMPLICIT); 3219#include "builtins.def" 3220#undef DEF_BUILTIN 3221 3222 build_common_builtin_nodes (); 3223 3224 targetm.init_builtins (); 3225 if (flag_mudflap) 3226 mudflap_init (); 3227} 3228 3229/* Build tree nodes and builtin functions common to both C and C++ language 3230 frontends. */ 3231 3232void 3233c_common_nodes_and_builtins (void) 3234{ 3235 int wchar_type_size; 3236 tree array_domain_type; 3237 tree va_list_ref_type_node; 3238 tree va_list_arg_type_node; 3239 3240 /* Define `int' and `char' first so that dbx will output them first. */ 3241 record_builtin_type (RID_INT, NULL, integer_type_node); 3242 record_builtin_type (RID_CHAR, "char", char_type_node); 3243 3244 /* `signed' is the same as `int'. FIXME: the declarations of "signed", 3245 "unsigned long", "long long unsigned" and "unsigned short" were in C++ 3246 but not C. Are the conditionals here needed? */ 3247 if (c_dialect_cxx ()) 3248 record_builtin_type (RID_SIGNED, NULL, integer_type_node); 3249 record_builtin_type (RID_LONG, "long int", long_integer_type_node); 3250 record_builtin_type (RID_UNSIGNED, "unsigned int", unsigned_type_node); 3251 record_builtin_type (RID_MAX, "long unsigned int", 3252 long_unsigned_type_node); 3253 if (c_dialect_cxx ()) 3254 record_builtin_type (RID_MAX, "unsigned long", long_unsigned_type_node); 3255 record_builtin_type (RID_MAX, "long long int", 3256 long_long_integer_type_node); 3257 record_builtin_type (RID_MAX, "long long unsigned int", 3258 long_long_unsigned_type_node); 3259 if (c_dialect_cxx ()) 3260 record_builtin_type (RID_MAX, "long long unsigned", 3261 long_long_unsigned_type_node); 3262 record_builtin_type (RID_SHORT, "short int", short_integer_type_node); 3263 record_builtin_type (RID_MAX, "short unsigned int", 3264 short_unsigned_type_node); 3265 if (c_dialect_cxx ()) 3266 record_builtin_type (RID_MAX, "unsigned short", 3267 short_unsigned_type_node); 3268 3269 /* Define both `signed char' and `unsigned char'. */ 3270 record_builtin_type (RID_MAX, "signed char", signed_char_type_node); 3271 record_builtin_type (RID_MAX, "unsigned char", unsigned_char_type_node); 3272 3273 /* These are types that c_common_type_for_size and 3274 c_common_type_for_mode use. */ 3275 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE, 3276 intQI_type_node)); 3277 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE, 3278 intHI_type_node)); 3279 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE, 3280 intSI_type_node)); 3281 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE, 3282 intDI_type_node)); 3283#if HOST_BITS_PER_WIDE_INT >= 64 3284 if (targetm.scalar_mode_supported_p (TImode)) 3285 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, 3286 get_identifier ("__int128_t"), 3287 intTI_type_node)); 3288#endif 3289 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE, 3290 unsigned_intQI_type_node)); 3291 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE, 3292 unsigned_intHI_type_node)); 3293 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE, 3294 unsigned_intSI_type_node)); 3295 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE, 3296 unsigned_intDI_type_node)); 3297#if HOST_BITS_PER_WIDE_INT >= 64 3298 if (targetm.scalar_mode_supported_p (TImode)) 3299 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, 3300 get_identifier ("__uint128_t"), 3301 unsigned_intTI_type_node)); 3302#endif 3303 3304 /* Create the widest literal types. */ 3305 widest_integer_literal_type_node 3306 = make_signed_type (HOST_BITS_PER_WIDE_INT * 2); 3307 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE, 3308 widest_integer_literal_type_node)); 3309 3310 widest_unsigned_literal_type_node 3311 = make_unsigned_type (HOST_BITS_PER_WIDE_INT * 2); 3312 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE, 3313 widest_unsigned_literal_type_node)); 3314 3315 /* `unsigned long' is the standard type for sizeof. 3316 Note that stddef.h uses `unsigned long', 3317 and this must agree, even if long and int are the same size. */ 3318 size_type_node = 3319 TREE_TYPE (identifier_global_value (get_identifier (SIZE_TYPE))); 3320 signed_size_type_node = c_common_signed_type (size_type_node); 3321 set_sizetype (size_type_node); 3322 3323 pid_type_node = 3324 TREE_TYPE (identifier_global_value (get_identifier (PID_TYPE))); 3325 3326 build_common_tree_nodes_2 (flag_short_double); 3327 3328 record_builtin_type (RID_FLOAT, NULL, float_type_node); 3329 record_builtin_type (RID_DOUBLE, NULL, double_type_node); 3330 record_builtin_type (RID_MAX, "long double", long_double_type_node); 3331 3332 /* Only supported decimal floating point extension if the target 3333 actually supports underlying modes. */ 3334 if (targetm.scalar_mode_supported_p (SDmode) 3335 && targetm.scalar_mode_supported_p (DDmode) 3336 && targetm.scalar_mode_supported_p (TDmode)) 3337 { 3338 record_builtin_type (RID_DFLOAT32, NULL, dfloat32_type_node); 3339 record_builtin_type (RID_DFLOAT64, NULL, dfloat64_type_node); 3340 record_builtin_type (RID_DFLOAT128, NULL, dfloat128_type_node); 3341 } 3342 3343 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, 3344 get_identifier ("complex int"), 3345 complex_integer_type_node)); 3346 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, 3347 get_identifier ("complex float"), 3348 complex_float_type_node)); 3349 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, 3350 get_identifier ("complex double"), 3351 complex_double_type_node)); 3352 lang_hooks.decls.pushdecl 3353 (build_decl (TYPE_DECL, get_identifier ("complex long double"), 3354 complex_long_double_type_node)); 3355 3356 if (c_dialect_cxx ()) 3357 /* For C++, make fileptr_type_node a distinct void * type until 3358 FILE type is defined. */ 3359 fileptr_type_node = build_variant_type_copy (ptr_type_node); 3360 3361 record_builtin_type (RID_VOID, NULL, void_type_node); 3362 3363 /* This node must not be shared. */ 3364 void_zero_node = make_node (INTEGER_CST); 3365 TREE_TYPE (void_zero_node) = void_type_node; 3366 3367 void_list_node = build_void_list_node (); 3368 3369 /* Make a type to be the domain of a few array types 3370 whose domains don't really matter. 3371 200 is small enough that it always fits in size_t 3372 and large enough that it can hold most function names for the 3373 initializations of __FUNCTION__ and __PRETTY_FUNCTION__. */ 3374 array_domain_type = build_index_type (size_int (200)); 3375 3376 /* Make a type for arrays of characters. 3377 With luck nothing will ever really depend on the length of this 3378 array type. */ 3379 char_array_type_node 3380 = build_array_type (char_type_node, array_domain_type); 3381 3382 /* Likewise for arrays of ints. */ 3383 int_array_type_node 3384 = build_array_type (integer_type_node, array_domain_type); 3385 3386 string_type_node = build_pointer_type (char_type_node); 3387 const_string_type_node 3388 = build_pointer_type (build_qualified_type 3389 (char_type_node, TYPE_QUAL_CONST)); 3390 3391 /* This is special for C++ so functions can be overloaded. */ 3392 wchar_type_node = get_identifier (MODIFIED_WCHAR_TYPE); 3393 wchar_type_node = TREE_TYPE (identifier_global_value (wchar_type_node)); 3394 wchar_type_size = TYPE_PRECISION (wchar_type_node); 3395 if (c_dialect_cxx ()) 3396 { 3397 if (TYPE_UNSIGNED (wchar_type_node)) 3398 wchar_type_node = make_unsigned_type (wchar_type_size); 3399 else 3400 wchar_type_node = make_signed_type (wchar_type_size); 3401 record_builtin_type (RID_WCHAR, "wchar_t", wchar_type_node); 3402 } 3403 else 3404 { 3405 signed_wchar_type_node = c_common_signed_type (wchar_type_node); 3406 unsigned_wchar_type_node = c_common_unsigned_type (wchar_type_node); 3407 } 3408 3409 /* This is for wide string constants. */ 3410 wchar_array_type_node 3411 = build_array_type (wchar_type_node, array_domain_type); 3412 3413 wint_type_node = 3414 TREE_TYPE (identifier_global_value (get_identifier (WINT_TYPE))); 3415 3416 intmax_type_node = 3417 TREE_TYPE (identifier_global_value (get_identifier (INTMAX_TYPE))); 3418 uintmax_type_node = 3419 TREE_TYPE (identifier_global_value (get_identifier (UINTMAX_TYPE))); 3420 3421 default_function_type = build_function_type (integer_type_node, NULL_TREE); 3422 ptrdiff_type_node 3423 = TREE_TYPE (identifier_global_value (get_identifier (PTRDIFF_TYPE))); 3424 unsigned_ptrdiff_type_node = c_common_unsigned_type (ptrdiff_type_node); 3425 3426 lang_hooks.decls.pushdecl 3427 (build_decl (TYPE_DECL, get_identifier ("__builtin_va_list"), 3428 va_list_type_node)); 3429 3430 if (TREE_CODE (va_list_type_node) == ARRAY_TYPE) 3431 { 3432 va_list_arg_type_node = va_list_ref_type_node = 3433 build_pointer_type (TREE_TYPE (va_list_type_node)); 3434 } 3435 else 3436 { 3437 va_list_arg_type_node = va_list_type_node; 3438 va_list_ref_type_node = build_reference_type (va_list_type_node); 3439 } 3440 3441 if (!flag_preprocess_only) 3442 c_define_builtins (va_list_ref_type_node, va_list_arg_type_node); 3443 3444 main_identifier_node = get_identifier ("main"); 3445 3446 /* Create the built-in __null node. It is important that this is 3447 not shared. */ 3448 null_node = make_node (INTEGER_CST); 3449 TREE_TYPE (null_node) = c_common_type_for_size (POINTER_SIZE, 0); 3450 3451 /* Since builtin_types isn't gc'ed, don't export these nodes. */ 3452 memset (builtin_types, 0, sizeof (builtin_types)); 3453} 3454 3455/* Look up the function in built_in_decls that corresponds to DECL 3456 and set ASMSPEC as its user assembler name. DECL must be a 3457 function decl that declares a builtin. */ 3458 3459void 3460set_builtin_user_assembler_name (tree decl, const char *asmspec) 3461{ 3462 tree builtin; 3463 gcc_assert (TREE_CODE (decl) == FUNCTION_DECL 3464 && DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL 3465 && asmspec != 0); 3466 3467 builtin = built_in_decls [DECL_FUNCTION_CODE (decl)]; 3468 set_user_assembler_name (builtin, asmspec); 3469 if (DECL_FUNCTION_CODE (decl) == BUILT_IN_MEMCPY) 3470 init_block_move_fn (asmspec); 3471 else if (DECL_FUNCTION_CODE (decl) == BUILT_IN_MEMSET) 3472 init_block_clear_fn (asmspec); 3473} 3474 3475/* The number of named compound-literals generated thus far. */ 3476static GTY(()) int compound_literal_number; 3477 3478/* Set DECL_NAME for DECL, a VAR_DECL for a compound-literal. */ 3479 3480void 3481set_compound_literal_name (tree decl) 3482{ 3483 char *name; 3484 ASM_FORMAT_PRIVATE_NAME (name, "__compound_literal", 3485 compound_literal_number); 3486 compound_literal_number++; 3487 DECL_NAME (decl) = get_identifier (name); 3488} 3489 3490tree 3491build_va_arg (tree expr, tree type) 3492{ 3493 return build1 (VA_ARG_EXPR, type, expr); 3494} 3495 3496 3497/* Linked list of disabled built-in functions. */ 3498 3499typedef struct disabled_builtin 3500{ 3501 const char *name; 3502 struct disabled_builtin *next; 3503} disabled_builtin; 3504static disabled_builtin *disabled_builtins = NULL; 3505 3506static bool builtin_function_disabled_p (const char *); 3507 3508/* Disable a built-in function specified by -fno-builtin-NAME. If NAME 3509 begins with "__builtin_", give an error. */ 3510 3511void 3512disable_builtin_function (const char *name) 3513{ 3514 if (strncmp (name, "__builtin_", strlen ("__builtin_")) == 0) 3515 error ("cannot disable built-in function %qs", name); 3516 else 3517 { 3518 disabled_builtin *new_disabled_builtin = XNEW (disabled_builtin); 3519 new_disabled_builtin->name = name; 3520 new_disabled_builtin->next = disabled_builtins; 3521 disabled_builtins = new_disabled_builtin; 3522 } 3523} 3524 3525 3526/* Return true if the built-in function NAME has been disabled, false 3527 otherwise. */ 3528 3529static bool 3530builtin_function_disabled_p (const char *name) 3531{ 3532 disabled_builtin *p; 3533 for (p = disabled_builtins; p != NULL; p = p->next) 3534 { 3535 if (strcmp (name, p->name) == 0) 3536 return true; 3537 } 3538 return false; 3539} 3540 3541 3542/* Worker for DEF_BUILTIN. 3543 Possibly define a builtin function with one or two names. 3544 Does not declare a non-__builtin_ function if flag_no_builtin, or if 3545 nonansi_p and flag_no_nonansi_builtin. */ 3546 3547static void 3548def_builtin_1 (enum built_in_function fncode, 3549 const char *name, 3550 enum built_in_class fnclass, 3551 tree fntype, tree libtype, 3552 bool both_p, bool fallback_p, bool nonansi_p, 3553 tree fnattrs, bool implicit_p) 3554{ 3555 tree decl; 3556 const char *libname; 3557 3558 if (fntype == error_mark_node) 3559 return; 3560 3561 gcc_assert ((!both_p && !fallback_p) 3562 || !strncmp (name, "__builtin_", 3563 strlen ("__builtin_"))); 3564 3565 libname = name + strlen ("__builtin_"); 3566 decl = lang_hooks.builtin_function (name, fntype, fncode, fnclass, 3567 (fallback_p ? libname : NULL), 3568 fnattrs); 3569 if (both_p 3570 && !flag_no_builtin && !builtin_function_disabled_p (libname) 3571 && !(nonansi_p && flag_no_nonansi_builtin)) 3572 lang_hooks.builtin_function (libname, libtype, fncode, fnclass, 3573 NULL, fnattrs); 3574 3575 built_in_decls[(int) fncode] = decl; 3576 if (implicit_p) 3577 implicit_built_in_decls[(int) fncode] = decl; 3578} 3579 3580/* Nonzero if the type T promotes to int. This is (nearly) the 3581 integral promotions defined in ISO C99 6.3.1.1/2. */ 3582 3583bool 3584c_promoting_integer_type_p (tree t) 3585{ 3586 switch (TREE_CODE (t)) 3587 { 3588 case INTEGER_TYPE: 3589 return (TYPE_MAIN_VARIANT (t) == char_type_node 3590 || TYPE_MAIN_VARIANT (t) == signed_char_type_node 3591 || TYPE_MAIN_VARIANT (t) == unsigned_char_type_node 3592 || TYPE_MAIN_VARIANT (t) == short_integer_type_node 3593 || TYPE_MAIN_VARIANT (t) == short_unsigned_type_node 3594 || TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node)); 3595 3596 case ENUMERAL_TYPE: 3597 /* ??? Technically all enumerations not larger than an int 3598 promote to an int. But this is used along code paths 3599 that only want to notice a size change. */ 3600 return TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node); 3601 3602 case BOOLEAN_TYPE: 3603 return 1; 3604 3605 default: 3606 return 0; 3607 } 3608} 3609 3610/* Return 1 if PARMS specifies a fixed number of parameters 3611 and none of their types is affected by default promotions. */ 3612 3613int 3614self_promoting_args_p (tree parms) 3615{ 3616 tree t; 3617 for (t = parms; t; t = TREE_CHAIN (t)) 3618 { 3619 tree type = TREE_VALUE (t); 3620 3621 if (type == error_mark_node) 3622 continue; 3623 3624 if (TREE_CHAIN (t) == 0 && type != void_type_node) 3625 return 0; 3626 3627 if (type == 0) 3628 return 0; 3629 3630 if (TYPE_MAIN_VARIANT (type) == float_type_node) 3631 return 0; 3632 3633 if (c_promoting_integer_type_p (type)) 3634 return 0; 3635 } 3636 return 1; 3637} 3638 3639/* Recursively examines the array elements of TYPE, until a non-array 3640 element type is found. */ 3641 3642tree 3643strip_array_types (tree type) 3644{ 3645 while (TREE_CODE (type) == ARRAY_TYPE) 3646 type = TREE_TYPE (type); 3647 3648 return type; 3649} 3650 3651/* Recursively remove any '*' or '&' operator from TYPE. */ 3652tree 3653strip_pointer_operator (tree t) 3654{ 3655 while (POINTER_TYPE_P (t)) 3656 t = TREE_TYPE (t); 3657 return t; 3658} 3659 3660/* Used to compare case labels. K1 and K2 are actually tree nodes 3661 representing case labels, or NULL_TREE for a `default' label. 3662 Returns -1 if K1 is ordered before K2, -1 if K1 is ordered after 3663 K2, and 0 if K1 and K2 are equal. */ 3664 3665int 3666case_compare (splay_tree_key k1, splay_tree_key k2) 3667{ 3668 /* Consider a NULL key (such as arises with a `default' label) to be 3669 smaller than anything else. */ 3670 if (!k1) 3671 return k2 ? -1 : 0; 3672 else if (!k2) 3673 return k1 ? 1 : 0; 3674 3675 return tree_int_cst_compare ((tree) k1, (tree) k2); 3676} 3677 3678/* Process a case label for the range LOW_VALUE ... HIGH_VALUE. If 3679 LOW_VALUE and HIGH_VALUE are both NULL_TREE then this case label is 3680 actually a `default' label. If only HIGH_VALUE is NULL_TREE, then 3681 case label was declared using the usual C/C++ syntax, rather than 3682 the GNU case range extension. CASES is a tree containing all the 3683 case ranges processed so far; COND is the condition for the 3684 switch-statement itself. Returns the CASE_LABEL_EXPR created, or 3685 ERROR_MARK_NODE if no CASE_LABEL_EXPR is created. */ 3686 3687tree 3688c_add_case_label (splay_tree cases, tree cond, tree orig_type, 3689 tree low_value, tree high_value) 3690{ 3691 tree type; 3692 tree label; 3693 tree case_label; 3694 splay_tree_node node; 3695 3696 /* Create the LABEL_DECL itself. */ 3697 label = create_artificial_label (); 3698 3699 /* If there was an error processing the switch condition, bail now 3700 before we get more confused. */ 3701 if (!cond || cond == error_mark_node) 3702 goto error_out; 3703 3704 if ((low_value && TREE_TYPE (low_value) 3705 && POINTER_TYPE_P (TREE_TYPE (low_value))) 3706 || (high_value && TREE_TYPE (high_value) 3707 && POINTER_TYPE_P (TREE_TYPE (high_value)))) 3708 { 3709 error ("pointers are not permitted as case values"); 3710 goto error_out; 3711 } 3712 3713 /* Case ranges are a GNU extension. */ 3714 if (high_value && pedantic) 3715 pedwarn ("range expressions in switch statements are non-standard"); 3716 3717 type = TREE_TYPE (cond); 3718 if (low_value) 3719 { 3720 low_value = check_case_value (low_value); 3721 low_value = convert_and_check (type, low_value); 3722 if (low_value == error_mark_node) 3723 goto error_out; 3724 } 3725 if (high_value) 3726 { 3727 high_value = check_case_value (high_value); 3728 high_value = convert_and_check (type, high_value); 3729 if (high_value == error_mark_node) 3730 goto error_out; 3731 } 3732 3733 if (low_value && high_value) 3734 { 3735 /* If the LOW_VALUE and HIGH_VALUE are the same, then this isn't 3736 really a case range, even though it was written that way. 3737 Remove the HIGH_VALUE to simplify later processing. */ 3738 if (tree_int_cst_equal (low_value, high_value)) 3739 high_value = NULL_TREE; 3740 else if (!tree_int_cst_lt (low_value, high_value)) 3741 warning (0, "empty range specified"); 3742 } 3743 3744 /* See if the case is in range of the type of the original testing 3745 expression. If both low_value and high_value are out of range, 3746 don't insert the case label and return NULL_TREE. */ 3747 if (low_value 3748 && !check_case_bounds (type, orig_type, 3749 &low_value, high_value ? &high_value : NULL)) 3750 return NULL_TREE; 3751 3752 /* Look up the LOW_VALUE in the table of case labels we already 3753 have. */ 3754 node = splay_tree_lookup (cases, (splay_tree_key) low_value); 3755 /* If there was not an exact match, check for overlapping ranges. 3756 There's no need to do this if there's no LOW_VALUE or HIGH_VALUE; 3757 that's a `default' label and the only overlap is an exact match. */ 3758 if (!node && (low_value || high_value)) 3759 { 3760 splay_tree_node low_bound; 3761 splay_tree_node high_bound; 3762 3763 /* Even though there wasn't an exact match, there might be an 3764 overlap between this case range and another case range. 3765 Since we've (inductively) not allowed any overlapping case 3766 ranges, we simply need to find the greatest low case label 3767 that is smaller that LOW_VALUE, and the smallest low case 3768 label that is greater than LOW_VALUE. If there is an overlap 3769 it will occur in one of these two ranges. */ 3770 low_bound = splay_tree_predecessor (cases, 3771 (splay_tree_key) low_value); 3772 high_bound = splay_tree_successor (cases, 3773 (splay_tree_key) low_value); 3774 3775 /* Check to see if the LOW_BOUND overlaps. It is smaller than 3776 the LOW_VALUE, so there is no need to check unless the 3777 LOW_BOUND is in fact itself a case range. */ 3778 if (low_bound 3779 && CASE_HIGH ((tree) low_bound->value) 3780 && tree_int_cst_compare (CASE_HIGH ((tree) low_bound->value), 3781 low_value) >= 0) 3782 node = low_bound; 3783 /* Check to see if the HIGH_BOUND overlaps. The low end of that 3784 range is bigger than the low end of the current range, so we 3785 are only interested if the current range is a real range, and 3786 not an ordinary case label. */ 3787 else if (high_bound 3788 && high_value 3789 && (tree_int_cst_compare ((tree) high_bound->key, 3790 high_value) 3791 <= 0)) 3792 node = high_bound; 3793 } 3794 /* If there was an overlap, issue an error. */ 3795 if (node) 3796 { 3797 tree duplicate = CASE_LABEL ((tree) node->value); 3798 3799 if (high_value) 3800 { 3801 error ("duplicate (or overlapping) case value"); 3802 error ("%Jthis is the first entry overlapping that value", duplicate); 3803 } 3804 else if (low_value) 3805 { 3806 error ("duplicate case value") ; 3807 error ("%Jpreviously used here", duplicate); 3808 } 3809 else 3810 { 3811 error ("multiple default labels in one switch"); 3812 error ("%Jthis is the first default label", duplicate); 3813 } 3814 goto error_out; 3815 } 3816 3817 /* Add a CASE_LABEL to the statement-tree. */ 3818 case_label = add_stmt (build_case_label (low_value, high_value, label)); 3819 /* Register this case label in the splay tree. */ 3820 splay_tree_insert (cases, 3821 (splay_tree_key) low_value, 3822 (splay_tree_value) case_label); 3823 3824 return case_label; 3825 3826 error_out: 3827 /* Add a label so that the back-end doesn't think that the beginning of 3828 the switch is unreachable. Note that we do not add a case label, as 3829 that just leads to duplicates and thence to failure later on. */ 3830 if (!cases->root) 3831 { 3832 tree t = create_artificial_label (); 3833 add_stmt (build_stmt (LABEL_EXPR, t)); 3834 } 3835 return error_mark_node; 3836} 3837 3838/* Subroutines of c_do_switch_warnings, called via splay_tree_foreach. 3839 Used to verify that case values match up with enumerator values. */ 3840 3841static void 3842match_case_to_enum_1 (tree key, tree type, tree label) 3843{ 3844 char buf[2 + 2*HOST_BITS_PER_WIDE_INT/4 + 1]; 3845 3846 /* ??? Not working too hard to print the double-word value. 3847 Should perhaps be done with %lwd in the diagnostic routines? */ 3848 if (TREE_INT_CST_HIGH (key) == 0) 3849 snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_UNSIGNED, 3850 TREE_INT_CST_LOW (key)); 3851 else if (!TYPE_UNSIGNED (type) 3852 && TREE_INT_CST_HIGH (key) == -1 3853 && TREE_INT_CST_LOW (key) != 0) 3854 snprintf (buf, sizeof (buf), "-" HOST_WIDE_INT_PRINT_UNSIGNED, 3855 -TREE_INT_CST_LOW (key)); 3856 else 3857 snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_DOUBLE_HEX, 3858 TREE_INT_CST_HIGH (key), TREE_INT_CST_LOW (key)); 3859 3860 if (TYPE_NAME (type) == 0) 3861 warning (0, "%Jcase value %qs not in enumerated type", 3862 CASE_LABEL (label), buf); 3863 else 3864 warning (0, "%Jcase value %qs not in enumerated type %qT", 3865 CASE_LABEL (label), buf, type); 3866} 3867 3868/* Subroutine of c_do_switch_warnings, called via splay_tree_foreach. 3869 Used to verify that case values match up with enumerator values. */ 3870 3871static int 3872match_case_to_enum (splay_tree_node node, void *data) 3873{ 3874 tree label = (tree) node->value; 3875 tree type = (tree) data; 3876 3877 /* Skip default case. */ 3878 if (!CASE_LOW (label)) 3879 return 0; 3880 3881 /* If CASE_LOW_SEEN is not set, that means CASE_LOW did not appear 3882 when we did our enum->case scan. Reset our scratch bit after. */ 3883 if (!CASE_LOW_SEEN (label)) 3884 match_case_to_enum_1 (CASE_LOW (label), type, label); 3885 else 3886 CASE_LOW_SEEN (label) = 0; 3887 3888 /* If CASE_HIGH is non-null, we have a range. If CASE_HIGH_SEEN is 3889 not set, that means that CASE_HIGH did not appear when we did our 3890 enum->case scan. Reset our scratch bit after. */ 3891 if (CASE_HIGH (label)) 3892 { 3893 if (!CASE_HIGH_SEEN (label)) 3894 match_case_to_enum_1 (CASE_HIGH (label), type, label); 3895 else 3896 CASE_HIGH_SEEN (label) = 0; 3897 } 3898 3899 return 0; 3900} 3901 3902/* Handle -Wswitch*. Called from the front end after parsing the 3903 switch construct. */ 3904/* ??? Should probably be somewhere generic, since other languages 3905 besides C and C++ would want this. At the moment, however, C/C++ 3906 are the only tree-ssa languages that support enumerations at all, 3907 so the point is moot. */ 3908 3909void 3910c_do_switch_warnings (splay_tree cases, location_t switch_location, 3911 tree type, tree cond) 3912{ 3913 splay_tree_node default_node; 3914 splay_tree_node node; 3915 tree chain; 3916 3917 if (!warn_switch && !warn_switch_enum && !warn_switch_default) 3918 return; 3919 3920 default_node = splay_tree_lookup (cases, (splay_tree_key) NULL); 3921 if (!default_node) 3922 warning (OPT_Wswitch_default, "%Hswitch missing default case", 3923 &switch_location); 3924 3925 /* From here on, we only care about about enumerated types. */ 3926 if (!type || TREE_CODE (type) != ENUMERAL_TYPE) 3927 return; 3928 3929 /* If the switch expression was an enumerated type, check that 3930 exactly all enumeration literals are covered by the cases. 3931 The check is made when -Wswitch was specified and there is no 3932 default case, or when -Wswitch-enum was specified. */ 3933 3934 if (!warn_switch_enum 3935 && !(warn_switch && !default_node)) 3936 return; 3937 3938 /* Clearing COND if it is not an integer constant simplifies 3939 the tests inside the loop below. */ 3940 if (TREE_CODE (cond) != INTEGER_CST) 3941 cond = NULL_TREE; 3942 3943 /* The time complexity here is O(N*lg(N)) worst case, but for the 3944 common case of monotonically increasing enumerators, it is 3945 O(N), since the nature of the splay tree will keep the next 3946 element adjacent to the root at all times. */ 3947 3948 for (chain = TYPE_VALUES (type); chain; chain = TREE_CHAIN (chain)) 3949 { 3950 tree value = TREE_VALUE (chain); 3951 node = splay_tree_lookup (cases, (splay_tree_key) value); 3952 if (node) 3953 { 3954 /* Mark the CASE_LOW part of the case entry as seen. */ 3955 tree label = (tree) node->value; 3956 CASE_LOW_SEEN (label) = 1; 3957 continue; 3958 } 3959 3960 /* Even though there wasn't an exact match, there might be a 3961 case range which includes the enumator's value. */ 3962 node = splay_tree_predecessor (cases, (splay_tree_key) value); 3963 if (node && CASE_HIGH ((tree) node->value)) 3964 { 3965 tree label = (tree) node->value; 3966 int cmp = tree_int_cst_compare (CASE_HIGH (label), value); 3967 if (cmp >= 0) 3968 { 3969 /* If we match the upper bound exactly, mark the CASE_HIGH 3970 part of the case entry as seen. */ 3971 if (cmp == 0) 3972 CASE_HIGH_SEEN (label) = 1; 3973 continue; 3974 } 3975 } 3976 3977 /* We've now determined that this enumerated literal isn't 3978 handled by the case labels of the switch statement. */ 3979 3980 /* If the switch expression is a constant, we only really care 3981 about whether that constant is handled by the switch. */ 3982 if (cond && tree_int_cst_compare (cond, value)) 3983 continue; 3984 3985 warning (0, "%Henumeration value %qE not handled in switch", 3986 &switch_location, TREE_PURPOSE (chain)); 3987 } 3988 3989 /* Warn if there are case expressions that don't correspond to 3990 enumerators. This can occur since C and C++ don't enforce 3991 type-checking of assignments to enumeration variables. 3992 3993 The time complexity here is now always O(N) worst case, since 3994 we should have marked both the lower bound and upper bound of 3995 every disjoint case label, with CASE_LOW_SEEN and CASE_HIGH_SEEN 3996 above. This scan also resets those fields. */ 3997 splay_tree_foreach (cases, match_case_to_enum, type); 3998} 3999 4000/* Finish an expression taking the address of LABEL (an 4001 IDENTIFIER_NODE). Returns an expression for the address. */ 4002 4003tree 4004finish_label_address_expr (tree label) 4005{ 4006 tree result; 4007 4008 if (pedantic) 4009 pedwarn ("taking the address of a label is non-standard"); 4010 4011 if (label == error_mark_node) 4012 return error_mark_node; 4013 4014 label = lookup_label (label); 4015 if (label == NULL_TREE) 4016 result = null_pointer_node; 4017 else 4018 { 4019 TREE_USED (label) = 1; 4020 result = build1 (ADDR_EXPR, ptr_type_node, label); 4021 /* The current function in not necessarily uninlinable. 4022 Computed gotos are incompatible with inlining, but the value 4023 here could be used only in a diagnostic, for example. */ 4024 } 4025 4026 return result; 4027} 4028 4029/* Hook used by expand_expr to expand language-specific tree codes. */ 4030/* The only things that should go here are bits needed to expand 4031 constant initializers. Everything else should be handled by the 4032 gimplification routines. */ 4033 4034rtx 4035c_expand_expr (tree exp, rtx target, enum machine_mode tmode, 4036 int modifier /* Actually enum_modifier. */, 4037 rtx *alt_rtl) 4038{ 4039 switch (TREE_CODE (exp)) 4040 { 4041 case COMPOUND_LITERAL_EXPR: 4042 { 4043 /* Initialize the anonymous variable declared in the compound 4044 literal, then return the variable. */ 4045 tree decl = COMPOUND_LITERAL_EXPR_DECL (exp); 4046 emit_local_var (decl); 4047 return expand_expr_real (decl, target, tmode, modifier, alt_rtl); 4048 } 4049 4050 default: 4051 gcc_unreachable (); 4052 } 4053} 4054 4055/* Hook used by staticp to handle language-specific tree codes. */ 4056 4057tree 4058c_staticp (tree exp) 4059{ 4060 return (TREE_CODE (exp) == COMPOUND_LITERAL_EXPR 4061 && TREE_STATIC (COMPOUND_LITERAL_EXPR_DECL (exp)) 4062 ? exp : NULL); 4063} 4064 4065 4066/* Given a boolean expression ARG, return a tree representing an increment 4067 or decrement (as indicated by CODE) of ARG. The front end must check for 4068 invalid cases (e.g., decrement in C++). */ 4069tree 4070boolean_increment (enum tree_code code, tree arg) 4071{ 4072 tree val; 4073 tree true_res = boolean_true_node; 4074 4075 arg = stabilize_reference (arg); 4076 switch (code) 4077 { 4078 case PREINCREMENT_EXPR: 4079 val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res); 4080 break; 4081 case POSTINCREMENT_EXPR: 4082 val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res); 4083 arg = save_expr (arg); 4084 val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg); 4085 val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val); 4086 break; 4087 case PREDECREMENT_EXPR: 4088 val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, 4089 invert_truthvalue (arg)); 4090 break; 4091 case POSTDECREMENT_EXPR: 4092 val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, 4093 invert_truthvalue (arg)); 4094 arg = save_expr (arg); 4095 val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg); 4096 val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val); 4097 break; 4098 default: 4099 gcc_unreachable (); 4100 } 4101 TREE_SIDE_EFFECTS (val) = 1; 4102 return val; 4103} 4104 4105/* Built-in macros for stddef.h, that require macros defined in this 4106 file. */ 4107void 4108c_stddef_cpp_builtins(void) 4109{ 4110 builtin_define_with_value ("__SIZE_TYPE__", SIZE_TYPE, 0); 4111 builtin_define_with_value ("__PTRDIFF_TYPE__", PTRDIFF_TYPE, 0); 4112 builtin_define_with_value ("__WCHAR_TYPE__", MODIFIED_WCHAR_TYPE, 0); 4113 builtin_define_with_value ("__WINT_TYPE__", WINT_TYPE, 0); 4114 builtin_define_with_value ("__INTMAX_TYPE__", INTMAX_TYPE, 0); 4115 builtin_define_with_value ("__UINTMAX_TYPE__", UINTMAX_TYPE, 0); 4116} 4117 4118static void 4119c_init_attributes (void) 4120{ 4121 /* Fill in the built_in_attributes array. */ 4122#define DEF_ATTR_NULL_TREE(ENUM) \ 4123 built_in_attributes[(int) ENUM] = NULL_TREE; 4124#define DEF_ATTR_INT(ENUM, VALUE) \ 4125 built_in_attributes[(int) ENUM] = build_int_cst (NULL_TREE, VALUE); 4126#define DEF_ATTR_IDENT(ENUM, STRING) \ 4127 built_in_attributes[(int) ENUM] = get_identifier (STRING); 4128#define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) \ 4129 built_in_attributes[(int) ENUM] \ 4130 = tree_cons (built_in_attributes[(int) PURPOSE], \ 4131 built_in_attributes[(int) VALUE], \ 4132 built_in_attributes[(int) CHAIN]); 4133#include "builtin-attrs.def" 4134#undef DEF_ATTR_NULL_TREE 4135#undef DEF_ATTR_INT 4136#undef DEF_ATTR_IDENT 4137#undef DEF_ATTR_TREE_LIST 4138} 4139 4140/* Attribute handlers common to C front ends. */ 4141 4142/* Handle a "packed" attribute; arguments as in 4143 struct attribute_spec.handler. */ 4144 4145static tree 4146handle_packed_attribute (tree *node, tree name, tree ARG_UNUSED (args), 4147 int flags, bool *no_add_attrs) 4148{ 4149 if (TYPE_P (*node)) 4150 { 4151 if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE)) 4152 *node = build_variant_type_copy (*node); 4153 TYPE_PACKED (*node) = 1; 4154 } 4155 else if (TREE_CODE (*node) == FIELD_DECL) 4156 { 4157 if (TYPE_ALIGN (TREE_TYPE (*node)) <= BITS_PER_UNIT) 4158 warning (OPT_Wattributes, 4159 "%qE attribute ignored for field of type %qT", 4160 name, TREE_TYPE (*node)); 4161 else 4162 DECL_PACKED (*node) = 1; 4163 } 4164 /* We can't set DECL_PACKED for a VAR_DECL, because the bit is 4165 used for DECL_REGISTER. It wouldn't mean anything anyway. 4166 We can't set DECL_PACKED on the type of a TYPE_DECL, because 4167 that changes what the typedef is typing. */ 4168 else 4169 { 4170 warning (OPT_Wattributes, "%qE attribute ignored", name); 4171 *no_add_attrs = true; 4172 } 4173 4174 return NULL_TREE; 4175} 4176 4177/* Handle a "nocommon" attribute; arguments as in 4178 struct attribute_spec.handler. */ 4179 4180static tree 4181handle_nocommon_attribute (tree *node, tree name, 4182 tree ARG_UNUSED (args), 4183 int ARG_UNUSED (flags), bool *no_add_attrs) 4184{ 4185 if (TREE_CODE (*node) == VAR_DECL) 4186 DECL_COMMON (*node) = 0; 4187 else 4188 { 4189 warning (OPT_Wattributes, "%qE attribute ignored", name); 4190 *no_add_attrs = true; 4191 } 4192 4193 return NULL_TREE; 4194} 4195 4196/* Handle a "common" attribute; arguments as in 4197 struct attribute_spec.handler. */ 4198 4199static tree 4200handle_common_attribute (tree *node, tree name, tree ARG_UNUSED (args), 4201 int ARG_UNUSED (flags), bool *no_add_attrs) 4202{ 4203 if (TREE_CODE (*node) == VAR_DECL) 4204 DECL_COMMON (*node) = 1; 4205 else 4206 { 4207 warning (OPT_Wattributes, "%qE attribute ignored", name); 4208 *no_add_attrs = true; 4209 } 4210 4211 return NULL_TREE; 4212} 4213 4214/* Handle a "noreturn" attribute; arguments as in 4215 struct attribute_spec.handler. */ 4216 4217static tree 4218handle_noreturn_attribute (tree *node, tree name, tree ARG_UNUSED (args), 4219 int ARG_UNUSED (flags), bool *no_add_attrs) 4220{ 4221 tree type = TREE_TYPE (*node); 4222 4223 /* See FIXME comment in c_common_attribute_table. */ 4224 if (TREE_CODE (*node) == FUNCTION_DECL) 4225 TREE_THIS_VOLATILE (*node) = 1; 4226 else if (TREE_CODE (type) == POINTER_TYPE 4227 && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE) 4228 TREE_TYPE (*node) 4229 = build_pointer_type 4230 (build_type_variant (TREE_TYPE (type), 4231 TYPE_READONLY (TREE_TYPE (type)), 1)); 4232 else 4233 { 4234 warning (OPT_Wattributes, "%qE attribute ignored", name); 4235 *no_add_attrs = true; 4236 } 4237 4238 return NULL_TREE; 4239} 4240 4241/* Handle a "noinline" attribute; arguments as in 4242 struct attribute_spec.handler. */ 4243 4244static tree 4245handle_noinline_attribute (tree *node, tree name, 4246 tree ARG_UNUSED (args), 4247 int ARG_UNUSED (flags), bool *no_add_attrs) 4248{ 4249 if (TREE_CODE (*node) == FUNCTION_DECL) 4250 DECL_UNINLINABLE (*node) = 1; 4251 else 4252 { 4253 warning (OPT_Wattributes, "%qE attribute ignored", name); 4254 *no_add_attrs = true; 4255 } 4256 4257 return NULL_TREE; 4258} 4259 4260/* Handle a "always_inline" attribute; arguments as in 4261 struct attribute_spec.handler. */ 4262 4263static tree 4264handle_always_inline_attribute (tree *node, tree name, 4265 tree ARG_UNUSED (args), 4266 int ARG_UNUSED (flags), 4267 bool *no_add_attrs) 4268{ 4269 if (TREE_CODE (*node) == FUNCTION_DECL) 4270 { 4271 /* Do nothing else, just set the attribute. We'll get at 4272 it later with lookup_attribute. */ 4273 } 4274 else 4275 { 4276 warning (OPT_Wattributes, "%qE attribute ignored", name); 4277 *no_add_attrs = true; 4278 } 4279 4280 return NULL_TREE; 4281} 4282 4283/* Handle a "gnu_inline" attribute; arguments as in 4284 struct attribute_spec.handler. */ 4285 4286static tree 4287handle_gnu_inline_attribute (tree *node, tree name, 4288 tree ARG_UNUSED (args), 4289 int ARG_UNUSED (flags), 4290 bool *no_add_attrs) 4291{ 4292 if (TREE_CODE (*node) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (*node)) 4293 { 4294 /* Do nothing else, just set the attribute. We'll get at 4295 it later with lookup_attribute. */ 4296 } 4297 else 4298 { 4299 warning (OPT_Wattributes, "%qE attribute ignored", name); 4300 *no_add_attrs = true; 4301 } 4302 4303 return NULL_TREE; 4304} 4305 4306/* Handle a "flatten" attribute; arguments as in 4307 struct attribute_spec.handler. */ 4308 4309static tree 4310handle_flatten_attribute (tree *node, tree name, 4311 tree args ATTRIBUTE_UNUSED, 4312 int flags ATTRIBUTE_UNUSED, bool *no_add_attrs) 4313{ 4314 if (TREE_CODE (*node) == FUNCTION_DECL) 4315 /* Do nothing else, just set the attribute. We'll get at 4316 it later with lookup_attribute. */ 4317 ; 4318 else 4319 { 4320 warning (OPT_Wattributes, "%qE attribute ignored", name); 4321 *no_add_attrs = true; 4322 } 4323 4324 return NULL_TREE; 4325} 4326 4327 4328/* Handle a "used" attribute; arguments as in 4329 struct attribute_spec.handler. */ 4330 4331static tree 4332handle_used_attribute (tree *pnode, tree name, tree ARG_UNUSED (args), 4333 int ARG_UNUSED (flags), bool *no_add_attrs) 4334{ 4335 tree node = *pnode; 4336 4337 if (TREE_CODE (node) == FUNCTION_DECL 4338 || (TREE_CODE (node) == VAR_DECL && TREE_STATIC (node))) 4339 { 4340 TREE_USED (node) = 1; 4341 DECL_PRESERVE_P (node) = 1; 4342 } 4343 else 4344 { 4345 warning (OPT_Wattributes, "%qE attribute ignored", name); 4346 *no_add_attrs = true; 4347 } 4348 4349 return NULL_TREE; 4350} 4351 4352/* Handle a "unused" attribute; arguments as in 4353 struct attribute_spec.handler. */ 4354 4355static tree 4356handle_unused_attribute (tree *node, tree name, tree ARG_UNUSED (args), 4357 int flags, bool *no_add_attrs) 4358{ 4359 if (DECL_P (*node)) 4360 { 4361 tree decl = *node; 4362 4363 if (TREE_CODE (decl) == PARM_DECL 4364 || TREE_CODE (decl) == VAR_DECL 4365 || TREE_CODE (decl) == FUNCTION_DECL 4366 || TREE_CODE (decl) == LABEL_DECL 4367 || TREE_CODE (decl) == TYPE_DECL) 4368 TREE_USED (decl) = 1; 4369 else 4370 { 4371 warning (OPT_Wattributes, "%qE attribute ignored", name); 4372 *no_add_attrs = true; 4373 } 4374 } 4375 else 4376 { 4377 if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE)) 4378 *node = build_variant_type_copy (*node); 4379 TREE_USED (*node) = 1; 4380 } 4381 4382 return NULL_TREE; 4383} 4384 4385/* Handle a "externally_visible" attribute; arguments as in 4386 struct attribute_spec.handler. */ 4387 4388static tree 4389handle_externally_visible_attribute (tree *pnode, tree name, 4390 tree ARG_UNUSED (args), 4391 int ARG_UNUSED (flags), 4392 bool *no_add_attrs) 4393{ 4394 tree node = *pnode; 4395 4396 if (TREE_CODE (node) == FUNCTION_DECL || TREE_CODE (node) == VAR_DECL) 4397 { 4398 if ((!TREE_STATIC (node) && TREE_CODE (node) != FUNCTION_DECL 4399 && !DECL_EXTERNAL (node)) || !TREE_PUBLIC (node)) 4400 { 4401 warning (OPT_Wattributes, 4402 "%qE attribute have effect only on public objects", name); 4403 *no_add_attrs = true; 4404 } 4405 } 4406 else 4407 { 4408 warning (OPT_Wattributes, "%qE attribute ignored", name); 4409 *no_add_attrs = true; 4410 } 4411 4412 return NULL_TREE; 4413} 4414 4415/* Handle a "const" attribute; arguments as in 4416 struct attribute_spec.handler. */ 4417 4418static tree 4419handle_const_attribute (tree *node, tree name, tree ARG_UNUSED (args), 4420 int ARG_UNUSED (flags), bool *no_add_attrs) 4421{ 4422 tree type = TREE_TYPE (*node); 4423 4424 /* See FIXME comment on noreturn in c_common_attribute_table. */ 4425 if (TREE_CODE (*node) == FUNCTION_DECL) 4426 TREE_READONLY (*node) = 1; 4427 else if (TREE_CODE (type) == POINTER_TYPE 4428 && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE) 4429 TREE_TYPE (*node) 4430 = build_pointer_type 4431 (build_type_variant (TREE_TYPE (type), 1, 4432 TREE_THIS_VOLATILE (TREE_TYPE (type)))); 4433 else 4434 { 4435 warning (OPT_Wattributes, "%qE attribute ignored", name); 4436 *no_add_attrs = true; 4437 } 4438 4439 return NULL_TREE; 4440} 4441 4442/* Handle a "transparent_union" attribute; arguments as in 4443 struct attribute_spec.handler. */ 4444 4445static tree 4446handle_transparent_union_attribute (tree *node, tree name, 4447 tree ARG_UNUSED (args), int flags, 4448 bool *no_add_attrs) 4449{ 4450 tree type = NULL; 4451 4452 *no_add_attrs = true; 4453 4454 if (DECL_P (*node)) 4455 { 4456 if (TREE_CODE (*node) != TYPE_DECL) 4457 goto ignored; 4458 node = &TREE_TYPE (*node); 4459 type = *node; 4460 } 4461 else if (TYPE_P (*node)) 4462 type = *node; 4463 else 4464 goto ignored; 4465 4466 if (TREE_CODE (type) == UNION_TYPE) 4467 { 4468 /* When IN_PLACE is set, leave the check for FIELDS and MODE to 4469 the code in finish_struct. */ 4470 if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE)) 4471 { 4472 if (TYPE_FIELDS (type) == NULL_TREE 4473 || TYPE_MODE (type) != DECL_MODE (TYPE_FIELDS (type))) 4474 goto ignored; 4475 4476 /* A type variant isn't good enough, since we don't a cast 4477 to such a type removed as a no-op. */ 4478 *node = type = build_duplicate_type (type); 4479 } 4480 4481 TYPE_TRANSPARENT_UNION (type) = 1; 4482 return NULL_TREE; 4483 } 4484 4485 ignored: 4486 warning (OPT_Wattributes, "%qE attribute ignored", name); 4487 return NULL_TREE; 4488} 4489 4490/* Handle a "constructor" attribute; arguments as in 4491 struct attribute_spec.handler. */ 4492 4493static tree 4494handle_constructor_attribute (tree *node, tree name, 4495 tree ARG_UNUSED (args), 4496 int ARG_UNUSED (flags), 4497 bool *no_add_attrs) 4498{ 4499 tree decl = *node; 4500 tree type = TREE_TYPE (decl); 4501 4502 if (TREE_CODE (decl) == FUNCTION_DECL 4503 && TREE_CODE (type) == FUNCTION_TYPE 4504 && decl_function_context (decl) == 0) 4505 { 4506 DECL_STATIC_CONSTRUCTOR (decl) = 1; 4507 TREE_USED (decl) = 1; 4508 } 4509 else 4510 { 4511 warning (OPT_Wattributes, "%qE attribute ignored", name); 4512 *no_add_attrs = true; 4513 } 4514 4515 return NULL_TREE; 4516} 4517 4518/* Handle a "destructor" attribute; arguments as in 4519 struct attribute_spec.handler. */ 4520 4521static tree 4522handle_destructor_attribute (tree *node, tree name, 4523 tree ARG_UNUSED (args), 4524 int ARG_UNUSED (flags), 4525 bool *no_add_attrs) 4526{ 4527 tree decl = *node; 4528 tree type = TREE_TYPE (decl); 4529 4530 if (TREE_CODE (decl) == FUNCTION_DECL 4531 && TREE_CODE (type) == FUNCTION_TYPE 4532 && decl_function_context (decl) == 0) 4533 { 4534 DECL_STATIC_DESTRUCTOR (decl) = 1; 4535 TREE_USED (decl) = 1; 4536 } 4537 else 4538 { 4539 warning (OPT_Wattributes, "%qE attribute ignored", name); 4540 *no_add_attrs = true; 4541 } 4542 4543 return NULL_TREE; 4544} 4545 4546/* Handle a "mode" attribute; arguments as in 4547 struct attribute_spec.handler. */ 4548 4549static tree 4550handle_mode_attribute (tree *node, tree name, tree args, 4551 int ARG_UNUSED (flags), bool *no_add_attrs) 4552{ 4553 tree type = *node; 4554 4555 *no_add_attrs = true; 4556 4557 if (TREE_CODE (TREE_VALUE (args)) != IDENTIFIER_NODE) 4558 warning (OPT_Wattributes, "%qE attribute ignored", name); 4559 else 4560 { 4561 int j; 4562 const char *p = IDENTIFIER_POINTER (TREE_VALUE (args)); 4563 int len = strlen (p); 4564 enum machine_mode mode = VOIDmode; 4565 tree typefm; 4566 bool valid_mode; 4567 4568 if (len > 4 && p[0] == '_' && p[1] == '_' 4569 && p[len - 1] == '_' && p[len - 2] == '_') 4570 { 4571 char *newp = (char *) alloca (len - 1); 4572 4573 strcpy (newp, &p[2]); 4574 newp[len - 4] = '\0'; 4575 p = newp; 4576 } 4577 4578 /* Change this type to have a type with the specified mode. 4579 First check for the special modes. */ 4580 if (!strcmp (p, "byte")) 4581 mode = byte_mode; 4582 else if (!strcmp (p, "word")) 4583 mode = word_mode; 4584 else if (!strcmp (p, "pointer")) 4585 mode = ptr_mode; 4586 else 4587 for (j = 0; j < NUM_MACHINE_MODES; j++) 4588 if (!strcmp (p, GET_MODE_NAME (j))) 4589 { 4590 mode = (enum machine_mode) j; 4591 break; 4592 } 4593 4594 if (mode == VOIDmode) 4595 { 4596 error ("unknown machine mode %qs", p); 4597 return NULL_TREE; 4598 } 4599 4600 valid_mode = false; 4601 switch (GET_MODE_CLASS (mode)) 4602 { 4603 case MODE_INT: 4604 case MODE_PARTIAL_INT: 4605 case MODE_FLOAT: 4606 case MODE_DECIMAL_FLOAT: 4607 valid_mode = targetm.scalar_mode_supported_p (mode); 4608 break; 4609 4610 case MODE_COMPLEX_INT: 4611 case MODE_COMPLEX_FLOAT: 4612 valid_mode = targetm.scalar_mode_supported_p (GET_MODE_INNER (mode)); 4613 break; 4614 4615 case MODE_VECTOR_INT: 4616 case MODE_VECTOR_FLOAT: 4617 warning (OPT_Wattributes, "specifying vector types with " 4618 "__attribute__ ((mode)) is deprecated"); 4619 warning (OPT_Wattributes, 4620 "use __attribute__ ((vector_size)) instead"); 4621 valid_mode = vector_mode_valid_p (mode); 4622 break; 4623 4624 default: 4625 break; 4626 } 4627 if (!valid_mode) 4628 { 4629 error ("unable to emulate %qs", p); 4630 return NULL_TREE; 4631 } 4632 4633 if (POINTER_TYPE_P (type)) 4634 { 4635 tree (*fn)(tree, enum machine_mode, bool); 4636 4637 if (!targetm.valid_pointer_mode (mode)) 4638 { 4639 error ("invalid pointer mode %qs", p); 4640 return NULL_TREE; 4641 } 4642 4643 if (TREE_CODE (type) == POINTER_TYPE) 4644 fn = build_pointer_type_for_mode; 4645 else 4646 fn = build_reference_type_for_mode; 4647 typefm = fn (TREE_TYPE (type), mode, false); 4648 } 4649 else 4650 typefm = lang_hooks.types.type_for_mode (mode, TYPE_UNSIGNED (type)); 4651 4652 if (typefm == NULL_TREE) 4653 { 4654 error ("no data type for mode %qs", p); 4655 return NULL_TREE; 4656 } 4657 else if (TREE_CODE (type) == ENUMERAL_TYPE) 4658 { 4659 /* For enumeral types, copy the precision from the integer 4660 type returned above. If not an INTEGER_TYPE, we can't use 4661 this mode for this type. */ 4662 if (TREE_CODE (typefm) != INTEGER_TYPE) 4663 { 4664 error ("cannot use mode %qs for enumeral types", p); 4665 return NULL_TREE; 4666 } 4667 4668 if (flags & ATTR_FLAG_TYPE_IN_PLACE) 4669 { 4670 TYPE_PRECISION (type) = TYPE_PRECISION (typefm); 4671 typefm = type; 4672 } 4673 else 4674 { 4675 /* We cannot build a type variant, as there's code that assumes 4676 that TYPE_MAIN_VARIANT has the same mode. This includes the 4677 debug generators. Instead, create a subrange type. This 4678 results in all of the enumeral values being emitted only once 4679 in the original, and the subtype gets them by reference. */ 4680 if (TYPE_UNSIGNED (type)) 4681 typefm = make_unsigned_type (TYPE_PRECISION (typefm)); 4682 else 4683 typefm = make_signed_type (TYPE_PRECISION (typefm)); 4684 TREE_TYPE (typefm) = type; 4685 } 4686 } 4687 else if (VECTOR_MODE_P (mode) 4688 ? TREE_CODE (type) != TREE_CODE (TREE_TYPE (typefm)) 4689 : TREE_CODE (type) != TREE_CODE (typefm)) 4690 { 4691 error ("mode %qs applied to inappropriate type", p); 4692 return NULL_TREE; 4693 } 4694 4695 *node = typefm; 4696 } 4697 4698 return NULL_TREE; 4699} 4700 4701/* Handle a "section" attribute; arguments as in 4702 struct attribute_spec.handler. */ 4703 4704static tree 4705handle_section_attribute (tree *node, tree ARG_UNUSED (name), tree args, 4706 int ARG_UNUSED (flags), bool *no_add_attrs) 4707{ 4708 tree decl = *node; 4709 4710 if (targetm.have_named_sections) 4711 { 4712 user_defined_section_attribute = true; 4713 4714 if ((TREE_CODE (decl) == FUNCTION_DECL 4715 || TREE_CODE (decl) == VAR_DECL) 4716 && TREE_CODE (TREE_VALUE (args)) == STRING_CST) 4717 { 4718 if (TREE_CODE (decl) == VAR_DECL 4719 && current_function_decl != NULL_TREE 4720 && !TREE_STATIC (decl)) 4721 { 4722 error ("%Jsection attribute cannot be specified for " 4723 "local variables", decl); 4724 *no_add_attrs = true; 4725 } 4726 4727 /* The decl may have already been given a section attribute 4728 from a previous declaration. Ensure they match. */ 4729 else if (DECL_SECTION_NAME (decl) != NULL_TREE 4730 && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)), 4731 TREE_STRING_POINTER (TREE_VALUE (args))) != 0) 4732 { 4733 error ("section of %q+D conflicts with previous declaration", 4734 *node); 4735 *no_add_attrs = true; 4736 } 4737 else 4738 DECL_SECTION_NAME (decl) = TREE_VALUE (args); 4739 } 4740 else 4741 { 4742 error ("section attribute not allowed for %q+D", *node); 4743 *no_add_attrs = true; 4744 } 4745 } 4746 else 4747 { 4748 error ("%Jsection attributes are not supported for this target", *node); 4749 *no_add_attrs = true; 4750 } 4751 4752 return NULL_TREE; 4753} 4754 4755/* Handle a "aligned" attribute; arguments as in 4756 struct attribute_spec.handler. */ 4757 4758static tree 4759handle_aligned_attribute (tree *node, tree ARG_UNUSED (name), tree args, 4760 int flags, bool *no_add_attrs) 4761{ 4762 tree decl = NULL_TREE; 4763 tree *type = NULL; 4764 int is_type = 0; 4765 tree align_expr = (args ? TREE_VALUE (args) 4766 : size_int (BIGGEST_ALIGNMENT / BITS_PER_UNIT)); 4767 int i; 4768 4769 if (DECL_P (*node)) 4770 { 4771 decl = *node; 4772 type = &TREE_TYPE (decl); 4773 is_type = TREE_CODE (*node) == TYPE_DECL; 4774 } 4775 else if (TYPE_P (*node)) 4776 type = node, is_type = 1; 4777 4778 if (TREE_CODE (align_expr) != INTEGER_CST) 4779 { 4780 error ("requested alignment is not a constant"); 4781 *no_add_attrs = true; 4782 } 4783 else if ((i = tree_log2 (align_expr)) == -1) 4784 { 4785 error ("requested alignment is not a power of 2"); 4786 *no_add_attrs = true; 4787 } 4788 else if (i > HOST_BITS_PER_INT - 2) 4789 { 4790 error ("requested alignment is too large"); 4791 *no_add_attrs = true; 4792 } 4793 else if (is_type) 4794 { 4795 /* If we have a TYPE_DECL, then copy the type, so that we 4796 don't accidentally modify a builtin type. See pushdecl. */ 4797 if (decl && TREE_TYPE (decl) != error_mark_node 4798 && DECL_ORIGINAL_TYPE (decl) == NULL_TREE) 4799 { 4800 tree tt = TREE_TYPE (decl); 4801 *type = build_variant_type_copy (*type); 4802 DECL_ORIGINAL_TYPE (decl) = tt; 4803 TYPE_NAME (*type) = decl; 4804 TREE_USED (*type) = TREE_USED (decl); 4805 TREE_TYPE (decl) = *type; 4806 } 4807 else if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE)) 4808 *type = build_variant_type_copy (*type); 4809 4810 TYPE_ALIGN (*type) = (1 << i) * BITS_PER_UNIT; 4811 TYPE_USER_ALIGN (*type) = 1; 4812 } 4813 else if (! VAR_OR_FUNCTION_DECL_P (decl) 4814 && TREE_CODE (decl) != FIELD_DECL) 4815 { 4816 error ("alignment may not be specified for %q+D", decl); 4817 *no_add_attrs = true; 4818 } 4819 else if (TREE_CODE (decl) == FUNCTION_DECL 4820 && DECL_ALIGN (decl) > (1 << i) * BITS_PER_UNIT) 4821 { 4822 if (DECL_USER_ALIGN (decl)) 4823 error ("alignment for %q+D was previously specified as %d " 4824 "and may not be decreased", decl, 4825 DECL_ALIGN (decl) / BITS_PER_UNIT); 4826 else 4827 error ("alignment for %q+D must be at least %d", decl, 4828 DECL_ALIGN (decl) / BITS_PER_UNIT); 4829 *no_add_attrs = true; 4830 } 4831 else 4832 { 4833 DECL_ALIGN (decl) = (1 << i) * BITS_PER_UNIT; 4834 DECL_USER_ALIGN (decl) = 1; 4835 } 4836 4837 return NULL_TREE; 4838} 4839 4840/* Handle a "weak" attribute; arguments as in 4841 struct attribute_spec.handler. */ 4842 4843static tree 4844handle_weak_attribute (tree *node, tree name, 4845 tree ARG_UNUSED (args), 4846 int ARG_UNUSED (flags), 4847 bool * ARG_UNUSED (no_add_attrs)) 4848{ 4849 if (TREE_CODE (*node) == FUNCTION_DECL 4850 || TREE_CODE (*node) == VAR_DECL) 4851 declare_weak (*node); 4852 else 4853 warning (OPT_Wattributes, "%qE attribute ignored", name); 4854 4855 4856 return NULL_TREE; 4857} 4858 4859/* Handle an "alias" attribute; arguments as in 4860 struct attribute_spec.handler. */ 4861 4862static tree 4863handle_alias_attribute (tree *node, tree name, tree args, 4864 int ARG_UNUSED (flags), bool *no_add_attrs) 4865{ 4866 tree decl = *node; 4867 4868 if ((TREE_CODE (decl) == FUNCTION_DECL && DECL_INITIAL (decl)) 4869 || (TREE_CODE (decl) != FUNCTION_DECL 4870 && TREE_PUBLIC (decl) && !DECL_EXTERNAL (decl)) 4871 /* A static variable declaration is always a tentative definition, 4872 but the alias is a non-tentative definition which overrides. */ 4873 || (TREE_CODE (decl) != FUNCTION_DECL 4874 && ! TREE_PUBLIC (decl) && DECL_INITIAL (decl))) 4875 { 4876 error ("%q+D defined both normally and as an alias", decl); 4877 *no_add_attrs = true; 4878 } 4879 4880 /* Note that the very first time we process a nested declaration, 4881 decl_function_context will not be set. Indeed, *would* never 4882 be set except for the DECL_INITIAL/DECL_EXTERNAL frobbery that 4883 we do below. After such frobbery, pushdecl would set the context. 4884 In any case, this is never what we want. */ 4885 else if (decl_function_context (decl) == 0 && current_function_decl == NULL) 4886 { 4887 tree id; 4888 4889 id = TREE_VALUE (args); 4890 if (TREE_CODE (id) != STRING_CST) 4891 { 4892 error ("alias argument not a string"); 4893 *no_add_attrs = true; 4894 return NULL_TREE; 4895 } 4896 id = get_identifier (TREE_STRING_POINTER (id)); 4897 /* This counts as a use of the object pointed to. */ 4898 TREE_USED (id) = 1; 4899 4900 if (TREE_CODE (decl) == FUNCTION_DECL) 4901 DECL_INITIAL (decl) = error_mark_node; 4902 else 4903 { 4904 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl))) 4905 DECL_EXTERNAL (decl) = 1; 4906 else 4907 DECL_EXTERNAL (decl) = 0; 4908 TREE_STATIC (decl) = 1; 4909 } 4910 } 4911 else 4912 { 4913 warning (OPT_Wattributes, "%qE attribute ignored", name); 4914 *no_add_attrs = true; 4915 } 4916 4917 return NULL_TREE; 4918} 4919 4920/* Handle a "weakref" attribute; arguments as in struct 4921 attribute_spec.handler. */ 4922 4923static tree 4924handle_weakref_attribute (tree *node, tree ARG_UNUSED (name), tree args, 4925 int flags, bool *no_add_attrs) 4926{ 4927 tree attr = NULL_TREE; 4928 4929 /* We must ignore the attribute when it is associated with 4930 local-scoped decls, since attribute alias is ignored and many 4931 such symbols do not even have a DECL_WEAK field. */ 4932 if (decl_function_context (*node) || current_function_decl) 4933 { 4934 warning (OPT_Wattributes, "%qE attribute ignored", name); 4935 *no_add_attrs = true; 4936 return NULL_TREE; 4937 } 4938 4939 /* The idea here is that `weakref("name")' mutates into `weakref, 4940 alias("name")', and weakref without arguments, in turn, 4941 implicitly adds weak. */ 4942 4943 if (args) 4944 { 4945 attr = tree_cons (get_identifier ("alias"), args, attr); 4946 attr = tree_cons (get_identifier ("weakref"), NULL_TREE, attr); 4947 4948 *no_add_attrs = true; 4949 4950 decl_attributes (node, attr, flags); 4951 } 4952 else 4953 { 4954 if (lookup_attribute ("alias", DECL_ATTRIBUTES (*node))) 4955 error ("%Jweakref attribute must appear before alias attribute", 4956 *node); 4957 4958 /* Can't call declare_weak because it wants this to be TREE_PUBLIC, 4959 and that isn't supported; and because it wants to add it to 4960 the list of weak decls, which isn't helpful. */ 4961 DECL_WEAK (*node) = 1; 4962 } 4963 4964 return NULL_TREE; 4965} 4966 4967/* Handle an "visibility" attribute; arguments as in 4968 struct attribute_spec.handler. */ 4969 4970static tree 4971handle_visibility_attribute (tree *node, tree name, tree args, 4972 int ARG_UNUSED (flags), 4973 bool *ARG_UNUSED (no_add_attrs)) 4974{ 4975 tree decl = *node; 4976 tree id = TREE_VALUE (args); 4977 enum symbol_visibility vis; 4978 4979 if (TYPE_P (*node)) 4980 { 4981 if (TREE_CODE (*node) == ENUMERAL_TYPE) 4982 /* OK */; 4983 else if (TREE_CODE (*node) != RECORD_TYPE && TREE_CODE (*node) != UNION_TYPE) 4984 { 4985 warning (OPT_Wattributes, "%qE attribute ignored on non-class types", 4986 name); 4987 return NULL_TREE; 4988 } 4989 else if (TYPE_FIELDS (*node)) 4990 { 4991 error ("%qE attribute ignored because %qT is already defined", 4992 name, *node); 4993 return NULL_TREE; 4994 } 4995 } 4996 else if (decl_function_context (decl) != 0 || !TREE_PUBLIC (decl)) 4997 { 4998 warning (OPT_Wattributes, "%qE attribute ignored", name); 4999 return NULL_TREE; 5000 } 5001 5002 if (TREE_CODE (id) != STRING_CST) 5003 { 5004 error ("visibility argument not a string"); 5005 return NULL_TREE; 5006 } 5007 5008 /* If this is a type, set the visibility on the type decl. */ 5009 if (TYPE_P (decl)) 5010 { 5011 decl = TYPE_NAME (decl); 5012 if (!decl) 5013 return NULL_TREE; 5014 if (TREE_CODE (decl) == IDENTIFIER_NODE) 5015 { 5016 warning (OPT_Wattributes, "%qE attribute ignored on types", 5017 name); 5018 return NULL_TREE; 5019 } 5020 } 5021 5022 if (strcmp (TREE_STRING_POINTER (id), "default") == 0) 5023 vis = VISIBILITY_DEFAULT; 5024 else if (strcmp (TREE_STRING_POINTER (id), "internal") == 0) 5025 vis = VISIBILITY_INTERNAL; 5026 else if (strcmp (TREE_STRING_POINTER (id), "hidden") == 0) 5027 vis = VISIBILITY_HIDDEN; 5028 else if (strcmp (TREE_STRING_POINTER (id), "protected") == 0) 5029 vis = VISIBILITY_PROTECTED; 5030 else 5031 { 5032 error ("visibility argument must be one of \"default\", \"hidden\", \"protected\" or \"internal\""); 5033 vis = VISIBILITY_DEFAULT; 5034 } 5035 5036 if (DECL_VISIBILITY_SPECIFIED (decl) 5037 && vis != DECL_VISIBILITY (decl) 5038 && lookup_attribute ("visibility", (TYPE_P (*node) 5039 ? TYPE_ATTRIBUTES (*node) 5040 : DECL_ATTRIBUTES (decl)))) 5041 error ("%qD redeclared with different visibility", decl); 5042 5043 DECL_VISIBILITY (decl) = vis; 5044 DECL_VISIBILITY_SPECIFIED (decl) = 1; 5045 5046 /* Go ahead and attach the attribute to the node as well. This is needed 5047 so we can determine whether we have VISIBILITY_DEFAULT because the 5048 visibility was not specified, or because it was explicitly overridden 5049 from the containing scope. */ 5050 5051 return NULL_TREE; 5052} 5053 5054/* Determine the ELF symbol visibility for DECL, which is either a 5055 variable or a function. It is an error to use this function if a 5056 definition of DECL is not available in this translation unit. 5057 Returns true if the final visibility has been determined by this 5058 function; false if the caller is free to make additional 5059 modifications. */ 5060 5061bool 5062c_determine_visibility (tree decl) 5063{ 5064 gcc_assert (TREE_CODE (decl) == VAR_DECL 5065 || TREE_CODE (decl) == FUNCTION_DECL); 5066 5067 /* If the user explicitly specified the visibility with an 5068 attribute, honor that. DECL_VISIBILITY will have been set during 5069 the processing of the attribute. We check for an explicit 5070 attribute, rather than just checking DECL_VISIBILITY_SPECIFIED, 5071 to distinguish the use of an attribute from the use of a "#pragma 5072 GCC visibility push(...)"; in the latter case we still want other 5073 considerations to be able to overrule the #pragma. */ 5074 if (lookup_attribute ("visibility", DECL_ATTRIBUTES (decl))) 5075 return true; 5076 5077 /* Anything that is exported must have default visibility. */ 5078 if (TARGET_DLLIMPORT_DECL_ATTRIBUTES 5079 && lookup_attribute ("dllexport", DECL_ATTRIBUTES (decl))) 5080 { 5081 DECL_VISIBILITY (decl) = VISIBILITY_DEFAULT; 5082 DECL_VISIBILITY_SPECIFIED (decl) = 1; 5083 return true; 5084 } 5085 5086 /* Set default visibility to whatever the user supplied with 5087 visibility_specified depending on #pragma GCC visibility. */ 5088 if (!DECL_VISIBILITY_SPECIFIED (decl)) 5089 { 5090 DECL_VISIBILITY (decl) = default_visibility; 5091 DECL_VISIBILITY_SPECIFIED (decl) = visibility_options.inpragma; 5092 } 5093 return false; 5094} 5095 5096/* Handle an "tls_model" attribute; arguments as in 5097 struct attribute_spec.handler. */ 5098 5099static tree 5100handle_tls_model_attribute (tree *node, tree name, tree args, 5101 int ARG_UNUSED (flags), bool *no_add_attrs) 5102{ 5103 tree id; 5104 tree decl = *node; 5105 enum tls_model kind; 5106 5107 *no_add_attrs = true; 5108 5109 if (!DECL_THREAD_LOCAL_P (decl)) 5110 { 5111 warning (OPT_Wattributes, "%qE attribute ignored", name); 5112 return NULL_TREE; 5113 } 5114 5115 kind = DECL_TLS_MODEL (decl); 5116 id = TREE_VALUE (args); 5117 if (TREE_CODE (id) != STRING_CST) 5118 { 5119 error ("tls_model argument not a string"); 5120 return NULL_TREE; 5121 } 5122 5123 if (!strcmp (TREE_STRING_POINTER (id), "local-exec")) 5124 kind = TLS_MODEL_LOCAL_EXEC; 5125 else if (!strcmp (TREE_STRING_POINTER (id), "initial-exec")) 5126 kind = TLS_MODEL_INITIAL_EXEC; 5127 else if (!strcmp (TREE_STRING_POINTER (id), "local-dynamic")) 5128 kind = optimize ? TLS_MODEL_LOCAL_DYNAMIC : TLS_MODEL_GLOBAL_DYNAMIC; 5129 else if (!strcmp (TREE_STRING_POINTER (id), "global-dynamic")) 5130 kind = TLS_MODEL_GLOBAL_DYNAMIC; 5131 else 5132 error ("tls_model argument must be one of \"local-exec\", \"initial-exec\", \"local-dynamic\" or \"global-dynamic\""); 5133 5134 DECL_TLS_MODEL (decl) = kind; 5135 return NULL_TREE; 5136} 5137 5138/* Handle a "no_instrument_function" attribute; arguments as in 5139 struct attribute_spec.handler. */ 5140 5141static tree 5142handle_no_instrument_function_attribute (tree *node, tree name, 5143 tree ARG_UNUSED (args), 5144 int ARG_UNUSED (flags), 5145 bool *no_add_attrs) 5146{ 5147 tree decl = *node; 5148 5149 if (TREE_CODE (decl) != FUNCTION_DECL) 5150 { 5151 error ("%J%qE attribute applies only to functions", decl, name); 5152 *no_add_attrs = true; 5153 } 5154 else if (DECL_INITIAL (decl)) 5155 { 5156 error ("%Jcan%'t set %qE attribute after definition", decl, name); 5157 *no_add_attrs = true; 5158 } 5159 else 5160 DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (decl) = 1; 5161 5162 return NULL_TREE; 5163} 5164 5165/* Handle a "malloc" attribute; arguments as in 5166 struct attribute_spec.handler. */ 5167 5168static tree 5169handle_malloc_attribute (tree *node, tree name, tree ARG_UNUSED (args), 5170 int ARG_UNUSED (flags), bool *no_add_attrs) 5171{ 5172 if (TREE_CODE (*node) == FUNCTION_DECL 5173 && POINTER_TYPE_P (TREE_TYPE (TREE_TYPE (*node)))) 5174 DECL_IS_MALLOC (*node) = 1; 5175 else 5176 { 5177 warning (OPT_Wattributes, "%qE attribute ignored", name); 5178 *no_add_attrs = true; 5179 } 5180 5181 return NULL_TREE; 5182} 5183 5184/* Handle a "returns_twice" attribute; arguments as in 5185 struct attribute_spec.handler. */ 5186 5187static tree 5188handle_returns_twice_attribute (tree *node, tree name, tree ARG_UNUSED (args), 5189 int ARG_UNUSED (flags), bool *no_add_attrs) 5190{ 5191 if (TREE_CODE (*node) == FUNCTION_DECL) 5192 DECL_IS_RETURNS_TWICE (*node) = 1; 5193 else 5194 { 5195 warning (OPT_Wattributes, "%qE attribute ignored", name); 5196 *no_add_attrs = true; 5197 } 5198 5199 return NULL_TREE; 5200} 5201 5202/* Handle a "no_limit_stack" attribute; arguments as in 5203 struct attribute_spec.handler. */ 5204 5205static tree 5206handle_no_limit_stack_attribute (tree *node, tree name, 5207 tree ARG_UNUSED (args), 5208 int ARG_UNUSED (flags), 5209 bool *no_add_attrs) 5210{ 5211 tree decl = *node; 5212 5213 if (TREE_CODE (decl) != FUNCTION_DECL) 5214 { 5215 error ("%J%qE attribute applies only to functions", decl, name); 5216 *no_add_attrs = true; 5217 } 5218 else if (DECL_INITIAL (decl)) 5219 { 5220 error ("%Jcan%'t set %qE attribute after definition", decl, name); 5221 *no_add_attrs = true; 5222 } 5223 else 5224 DECL_NO_LIMIT_STACK (decl) = 1; 5225 5226 return NULL_TREE; 5227} 5228 5229/* Handle a "pure" attribute; arguments as in 5230 struct attribute_spec.handler. */ 5231 5232static tree 5233handle_pure_attribute (tree *node, tree name, tree ARG_UNUSED (args), 5234 int ARG_UNUSED (flags), bool *no_add_attrs) 5235{ 5236 if (TREE_CODE (*node) == FUNCTION_DECL) 5237 DECL_IS_PURE (*node) = 1; 5238 /* ??? TODO: Support types. */ 5239 else 5240 { 5241 warning (OPT_Wattributes, "%qE attribute ignored", name); 5242 *no_add_attrs = true; 5243 } 5244 5245 return NULL_TREE; 5246} 5247 5248/* Handle a "no vops" attribute; arguments as in 5249 struct attribute_spec.handler. */ 5250 5251static tree 5252handle_novops_attribute (tree *node, tree ARG_UNUSED (name), 5253 tree ARG_UNUSED (args), int ARG_UNUSED (flags), 5254 bool *ARG_UNUSED (no_add_attrs)) 5255{ 5256 gcc_assert (TREE_CODE (*node) == FUNCTION_DECL); 5257 DECL_IS_NOVOPS (*node) = 1; 5258 return NULL_TREE; 5259} 5260 5261/* Handle a "deprecated" attribute; arguments as in 5262 struct attribute_spec.handler. */ 5263 5264static tree 5265handle_deprecated_attribute (tree *node, tree name, 5266 tree ARG_UNUSED (args), int flags, 5267 bool *no_add_attrs) 5268{ 5269 tree type = NULL_TREE; 5270 int warn = 0; 5271 tree what = NULL_TREE; 5272 5273 if (DECL_P (*node)) 5274 { 5275 tree decl = *node; 5276 type = TREE_TYPE (decl); 5277 5278 if (TREE_CODE (decl) == TYPE_DECL 5279 || TREE_CODE (decl) == PARM_DECL 5280 || TREE_CODE (decl) == VAR_DECL 5281 || TREE_CODE (decl) == FUNCTION_DECL 5282 || TREE_CODE (decl) == FIELD_DECL) 5283 TREE_DEPRECATED (decl) = 1; 5284 else 5285 warn = 1; 5286 } 5287 else if (TYPE_P (*node)) 5288 { 5289 if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE)) 5290 *node = build_variant_type_copy (*node); 5291 TREE_DEPRECATED (*node) = 1; 5292 type = *node; 5293 } 5294 else 5295 warn = 1; 5296 5297 if (warn) 5298 { 5299 *no_add_attrs = true; 5300 if (type && TYPE_NAME (type)) 5301 { 5302 if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE) 5303 what = TYPE_NAME (*node); 5304 else if (TREE_CODE (TYPE_NAME (type)) == TYPE_DECL 5305 && DECL_NAME (TYPE_NAME (type))) 5306 what = DECL_NAME (TYPE_NAME (type)); 5307 } 5308 if (what) 5309 warning (OPT_Wattributes, "%qE attribute ignored for %qE", name, what); 5310 else 5311 warning (OPT_Wattributes, "%qE attribute ignored", name); 5312 } 5313 5314 return NULL_TREE; 5315} 5316 5317/* Handle a "vector_size" attribute; arguments as in 5318 struct attribute_spec.handler. */ 5319 5320static tree 5321handle_vector_size_attribute (tree *node, tree name, tree args, 5322 int ARG_UNUSED (flags), 5323 bool *no_add_attrs) 5324{ 5325 unsigned HOST_WIDE_INT vecsize, nunits; 5326 enum machine_mode orig_mode; 5327 tree type = *node, new_type, size; 5328 5329 *no_add_attrs = true; 5330 5331 size = TREE_VALUE (args); 5332 5333 if (!host_integerp (size, 1)) 5334 { 5335 warning (OPT_Wattributes, "%qE attribute ignored", name); 5336 return NULL_TREE; 5337 } 5338 5339 /* Get the vector size (in bytes). */ 5340 vecsize = tree_low_cst (size, 1); 5341 5342 /* We need to provide for vector pointers, vector arrays, and 5343 functions returning vectors. For example: 5344 5345 __attribute__((vector_size(16))) short *foo; 5346 5347 In this case, the mode is SI, but the type being modified is 5348 HI, so we need to look further. */ 5349 5350 while (POINTER_TYPE_P (type) 5351 || TREE_CODE (type) == FUNCTION_TYPE 5352 || TREE_CODE (type) == METHOD_TYPE 5353 || TREE_CODE (type) == ARRAY_TYPE) 5354 type = TREE_TYPE (type); 5355 5356 /* Get the mode of the type being modified. */ 5357 orig_mode = TYPE_MODE (type); 5358 5359 if (TREE_CODE (type) == RECORD_TYPE 5360 || TREE_CODE (type) == UNION_TYPE 5361 || TREE_CODE (type) == VECTOR_TYPE 5362 || (!SCALAR_FLOAT_MODE_P (orig_mode) 5363 && GET_MODE_CLASS (orig_mode) != MODE_INT) 5364 || !host_integerp (TYPE_SIZE_UNIT (type), 1)) 5365 { 5366 error ("invalid vector type for attribute %qE", name); 5367 return NULL_TREE; 5368 } 5369 5370 if (vecsize % tree_low_cst (TYPE_SIZE_UNIT (type), 1)) 5371 { 5372 error ("vector size not an integral multiple of component size"); 5373 return NULL; 5374 } 5375 5376 if (vecsize == 0) 5377 { 5378 error ("zero vector size"); 5379 return NULL; 5380 } 5381 5382 /* Calculate how many units fit in the vector. */ 5383 nunits = vecsize / tree_low_cst (TYPE_SIZE_UNIT (type), 1); 5384 if (nunits & (nunits - 1)) 5385 { 5386 error ("number of components of the vector not a power of two"); 5387 return NULL_TREE; 5388 } 5389 5390 new_type = build_vector_type (type, nunits); 5391 5392 /* Build back pointers if needed. */ 5393 *node = reconstruct_complex_type (*node, new_type); 5394 5395 return NULL_TREE; 5396} 5397 5398/* Handle the "nonnull" attribute. */ 5399static tree 5400handle_nonnull_attribute (tree *node, tree ARG_UNUSED (name), 5401 tree args, int ARG_UNUSED (flags), 5402 bool *no_add_attrs) 5403{ 5404 tree type = *node; 5405 unsigned HOST_WIDE_INT attr_arg_num; 5406 5407 /* If no arguments are specified, all pointer arguments should be 5408 non-null. Verify a full prototype is given so that the arguments 5409 will have the correct types when we actually check them later. */ 5410 if (!args) 5411 { 5412 if (!TYPE_ARG_TYPES (type)) 5413 { 5414 error ("nonnull attribute without arguments on a non-prototype"); 5415 *no_add_attrs = true; 5416 } 5417 return NULL_TREE; 5418 } 5419 5420 /* Argument list specified. Verify that each argument number references 5421 a pointer argument. */ 5422 for (attr_arg_num = 1; args; args = TREE_CHAIN (args)) 5423 { 5424 tree argument; 5425 unsigned HOST_WIDE_INT arg_num = 0, ck_num; 5426 5427 if (!get_nonnull_operand (TREE_VALUE (args), &arg_num)) 5428 { 5429 error ("nonnull argument has invalid operand number (argument %lu)", 5430 (unsigned long) attr_arg_num); 5431 *no_add_attrs = true; 5432 return NULL_TREE; 5433 } 5434 5435 argument = TYPE_ARG_TYPES (type); 5436 if (argument) 5437 { 5438 for (ck_num = 1; ; ck_num++) 5439 { 5440 if (!argument || ck_num == arg_num) 5441 break; 5442 argument = TREE_CHAIN (argument); 5443 } 5444 5445 if (!argument 5446 || TREE_CODE (TREE_VALUE (argument)) == VOID_TYPE) 5447 { 5448 error ("nonnull argument with out-of-range operand number (argument %lu, operand %lu)", 5449 (unsigned long) attr_arg_num, (unsigned long) arg_num); 5450 *no_add_attrs = true; 5451 return NULL_TREE; 5452 } 5453 5454 if (TREE_CODE (TREE_VALUE (argument)) != POINTER_TYPE) 5455 { 5456 error ("nonnull argument references non-pointer operand (argument %lu, operand %lu)", 5457 (unsigned long) attr_arg_num, (unsigned long) arg_num); 5458 *no_add_attrs = true; 5459 return NULL_TREE; 5460 } 5461 } 5462 } 5463 5464 return NULL_TREE; 5465} 5466 5467/* Check the argument list of a function call for null in argument slots 5468 that are marked as requiring a non-null pointer argument. */ 5469 5470static void 5471check_function_nonnull (tree attrs, tree params) 5472{ 5473 tree a, args, param; 5474 int param_num; 5475 5476 for (a = attrs; a; a = TREE_CHAIN (a)) 5477 { 5478 if (is_attribute_p ("nonnull", TREE_PURPOSE (a))) 5479 { 5480 args = TREE_VALUE (a); 5481 5482 /* Walk the argument list. If we encounter an argument number we 5483 should check for non-null, do it. If the attribute has no args, 5484 then every pointer argument is checked (in which case the check 5485 for pointer type is done in check_nonnull_arg). */ 5486 for (param = params, param_num = 1; ; 5487 param_num++, param = TREE_CHAIN (param)) 5488 { 5489 if (!param) 5490 break; 5491 if (!args || nonnull_check_p (args, param_num)) 5492 check_function_arguments_recurse (check_nonnull_arg, NULL, 5493 TREE_VALUE (param), 5494 param_num); 5495 } 5496 } 5497 } 5498} 5499 5500/* Check that the Nth argument of a function call (counting backwards 5501 from the end) is a (pointer)0. */ 5502 5503static void 5504check_function_sentinel (tree attrs, tree params, tree typelist) 5505{ 5506 tree attr = lookup_attribute ("sentinel", attrs); 5507 5508 if (attr) 5509 { 5510 /* Skip over the named arguments. */ 5511 while (typelist && params) 5512 { 5513 typelist = TREE_CHAIN (typelist); 5514 params = TREE_CHAIN (params); 5515 } 5516 5517 if (typelist || !params) 5518 warning (OPT_Wformat, 5519 "not enough variable arguments to fit a sentinel"); 5520 else 5521 { 5522 tree sentinel, end; 5523 unsigned pos = 0; 5524 5525 if (TREE_VALUE (attr)) 5526 { 5527 tree p = TREE_VALUE (TREE_VALUE (attr)); 5528 pos = TREE_INT_CST_LOW (p); 5529 } 5530 5531 sentinel = end = params; 5532 5533 /* Advance `end' ahead of `sentinel' by `pos' positions. */ 5534 while (pos > 0 && TREE_CHAIN (end)) 5535 { 5536 pos--; 5537 end = TREE_CHAIN (end); 5538 } 5539 if (pos > 0) 5540 { 5541 warning (OPT_Wformat, 5542 "not enough variable arguments to fit a sentinel"); 5543 return; 5544 } 5545 5546 /* Now advance both until we find the last parameter. */ 5547 while (TREE_CHAIN (end)) 5548 { 5549 end = TREE_CHAIN (end); 5550 sentinel = TREE_CHAIN (sentinel); 5551 } 5552 5553 /* Validate the sentinel. */ 5554 if ((!POINTER_TYPE_P (TREE_TYPE (TREE_VALUE (sentinel))) 5555 || !integer_zerop (TREE_VALUE (sentinel))) 5556 /* Although __null (in C++) is only an integer we allow it 5557 nevertheless, as we are guaranteed that it's exactly 5558 as wide as a pointer, and we don't want to force 5559 users to cast the NULL they have written there. 5560 We warn with -Wstrict-null-sentinel, though. */ 5561 && (warn_strict_null_sentinel 5562 || null_node != TREE_VALUE (sentinel))) 5563 warning (OPT_Wformat, "missing sentinel in function call"); 5564 } 5565 } 5566} 5567 5568/* Helper for check_function_nonnull; given a list of operands which 5569 must be non-null in ARGS, determine if operand PARAM_NUM should be 5570 checked. */ 5571 5572static bool 5573nonnull_check_p (tree args, unsigned HOST_WIDE_INT param_num) 5574{ 5575 unsigned HOST_WIDE_INT arg_num = 0; 5576 5577 for (; args; args = TREE_CHAIN (args)) 5578 { 5579 bool found = get_nonnull_operand (TREE_VALUE (args), &arg_num); 5580 5581 gcc_assert (found); 5582 5583 if (arg_num == param_num) 5584 return true; 5585 } 5586 return false; 5587} 5588 5589/* Check that the function argument PARAM (which is operand number 5590 PARAM_NUM) is non-null. This is called by check_function_nonnull 5591 via check_function_arguments_recurse. */ 5592 5593static void 5594check_nonnull_arg (void * ARG_UNUSED (ctx), tree param, 5595 unsigned HOST_WIDE_INT param_num) 5596{ 5597 /* Just skip checking the argument if it's not a pointer. This can 5598 happen if the "nonnull" attribute was given without an operand 5599 list (which means to check every pointer argument). */ 5600 5601 if (TREE_CODE (TREE_TYPE (param)) != POINTER_TYPE) 5602 return; 5603 5604 if (integer_zerop (param)) 5605 warning (OPT_Wnonnull, "null argument where non-null required " 5606 "(argument %lu)", (unsigned long) param_num); 5607} 5608 5609/* Helper for nonnull attribute handling; fetch the operand number 5610 from the attribute argument list. */ 5611 5612static bool 5613get_nonnull_operand (tree arg_num_expr, unsigned HOST_WIDE_INT *valp) 5614{ 5615 /* Verify the arg number is a constant. */ 5616 if (TREE_CODE (arg_num_expr) != INTEGER_CST 5617 || TREE_INT_CST_HIGH (arg_num_expr) != 0) 5618 return false; 5619 5620 *valp = TREE_INT_CST_LOW (arg_num_expr); 5621 return true; 5622} 5623 5624/* Handle a "nothrow" attribute; arguments as in 5625 struct attribute_spec.handler. */ 5626 5627static tree 5628handle_nothrow_attribute (tree *node, tree name, tree ARG_UNUSED (args), 5629 int ARG_UNUSED (flags), bool *no_add_attrs) 5630{ 5631 if (TREE_CODE (*node) == FUNCTION_DECL) 5632 TREE_NOTHROW (*node) = 1; 5633 /* ??? TODO: Support types. */ 5634 else 5635 { 5636 warning (OPT_Wattributes, "%qE attribute ignored", name); 5637 *no_add_attrs = true; 5638 } 5639 5640 return NULL_TREE; 5641} 5642 5643/* Handle a "cleanup" attribute; arguments as in 5644 struct attribute_spec.handler. */ 5645 5646static tree 5647handle_cleanup_attribute (tree *node, tree name, tree args, 5648 int ARG_UNUSED (flags), bool *no_add_attrs) 5649{ 5650 tree decl = *node; 5651 tree cleanup_id, cleanup_decl; 5652 5653 /* ??? Could perhaps support cleanups on TREE_STATIC, much like we do 5654 for global destructors in C++. This requires infrastructure that 5655 we don't have generically at the moment. It's also not a feature 5656 we'd be missing too much, since we do have attribute constructor. */ 5657 if (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl)) 5658 { 5659 warning (OPT_Wattributes, "%qE attribute ignored", name); 5660 *no_add_attrs = true; 5661 return NULL_TREE; 5662 } 5663 5664 /* Verify that the argument is a function in scope. */ 5665 /* ??? We could support pointers to functions here as well, if 5666 that was considered desirable. */ 5667 cleanup_id = TREE_VALUE (args); 5668 if (TREE_CODE (cleanup_id) != IDENTIFIER_NODE) 5669 { 5670 error ("cleanup argument not an identifier"); 5671 *no_add_attrs = true; 5672 return NULL_TREE; 5673 } 5674 cleanup_decl = lookup_name (cleanup_id); 5675 if (!cleanup_decl || TREE_CODE (cleanup_decl) != FUNCTION_DECL) 5676 { 5677 error ("cleanup argument not a function"); 5678 *no_add_attrs = true; 5679 return NULL_TREE; 5680 } 5681 5682 /* That the function has proper type is checked with the 5683 eventual call to build_function_call. */ 5684 5685 return NULL_TREE; 5686} 5687 5688/* Handle a "warn_unused_result" attribute. No special handling. */ 5689 5690static tree 5691handle_warn_unused_result_attribute (tree *node, tree name, 5692 tree ARG_UNUSED (args), 5693 int ARG_UNUSED (flags), bool *no_add_attrs) 5694{ 5695 /* Ignore the attribute for functions not returning any value. */ 5696 if (VOID_TYPE_P (TREE_TYPE (*node))) 5697 { 5698 warning (OPT_Wattributes, "%qE attribute ignored", name); 5699 *no_add_attrs = true; 5700 } 5701 5702 return NULL_TREE; 5703} 5704 5705/* Handle a "sentinel" attribute. */ 5706 5707static tree 5708handle_sentinel_attribute (tree *node, tree name, tree args, 5709 int ARG_UNUSED (flags), bool *no_add_attrs) 5710{ 5711 tree params = TYPE_ARG_TYPES (*node); 5712 5713 if (!params) 5714 { 5715 warning (OPT_Wattributes, 5716 "%qE attribute requires prototypes with named arguments", name); 5717 *no_add_attrs = true; 5718 } 5719 else 5720 { 5721 while (TREE_CHAIN (params)) 5722 params = TREE_CHAIN (params); 5723 5724 if (VOID_TYPE_P (TREE_VALUE (params))) 5725 { 5726 warning (OPT_Wattributes, 5727 "%qE attribute only applies to variadic functions", name); 5728 *no_add_attrs = true; 5729 } 5730 } 5731 5732 if (args) 5733 { 5734 tree position = TREE_VALUE (args); 5735 5736 if (TREE_CODE (position) != INTEGER_CST) 5737 { 5738 warning (0, "requested position is not an integer constant"); 5739 *no_add_attrs = true; 5740 } 5741 else 5742 { 5743 if (tree_int_cst_lt (position, integer_zero_node)) 5744 { 5745 warning (0, "requested position is less than zero"); 5746 *no_add_attrs = true; 5747 } 5748 } 5749 } 5750 5751 return NULL_TREE; 5752} 5753 5754/* Check for valid arguments being passed to a function. */ 5755void 5756check_function_arguments (tree attrs, tree params, tree typelist) 5757{ 5758 /* Check for null being passed in a pointer argument that must be 5759 non-null. We also need to do this if format checking is enabled. */ 5760 5761 if (warn_nonnull) 5762 check_function_nonnull (attrs, params); 5763 5764 /* Check for errors in format strings. */ 5765 5766 if (warn_format || warn_missing_format_attribute) 5767 check_function_format (attrs, params); 5768 5769 if (warn_format) 5770 check_function_sentinel (attrs, params, typelist); 5771} 5772 5773/* Generic argument checking recursion routine. PARAM is the argument to 5774 be checked. PARAM_NUM is the number of the argument. CALLBACK is invoked 5775 once the argument is resolved. CTX is context for the callback. */ 5776void 5777check_function_arguments_recurse (void (*callback) 5778 (void *, tree, unsigned HOST_WIDE_INT), 5779 void *ctx, tree param, 5780 unsigned HOST_WIDE_INT param_num) 5781{ 5782 if ((TREE_CODE (param) == NOP_EXPR || TREE_CODE (param) == CONVERT_EXPR) 5783 && (TYPE_PRECISION (TREE_TYPE (param)) 5784 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (param, 0))))) 5785 { 5786 /* Strip coercion. */ 5787 check_function_arguments_recurse (callback, ctx, 5788 TREE_OPERAND (param, 0), param_num); 5789 return; 5790 } 5791 5792 if (TREE_CODE (param) == CALL_EXPR) 5793 { 5794 tree type = TREE_TYPE (TREE_TYPE (TREE_OPERAND (param, 0))); 5795 tree attrs; 5796 bool found_format_arg = false; 5797 5798 /* See if this is a call to a known internationalization function 5799 that modifies a format arg. Such a function may have multiple 5800 format_arg attributes (for example, ngettext). */ 5801 5802 for (attrs = TYPE_ATTRIBUTES (type); 5803 attrs; 5804 attrs = TREE_CHAIN (attrs)) 5805 if (is_attribute_p ("format_arg", TREE_PURPOSE (attrs))) 5806 { 5807 tree inner_args; 5808 tree format_num_expr; 5809 int format_num; 5810 int i; 5811 5812 /* Extract the argument number, which was previously checked 5813 to be valid. */ 5814 format_num_expr = TREE_VALUE (TREE_VALUE (attrs)); 5815 5816 gcc_assert (TREE_CODE (format_num_expr) == INTEGER_CST 5817 && !TREE_INT_CST_HIGH (format_num_expr)); 5818 5819 format_num = TREE_INT_CST_LOW (format_num_expr); 5820 5821 for (inner_args = TREE_OPERAND (param, 1), i = 1; 5822 inner_args != 0; 5823 inner_args = TREE_CHAIN (inner_args), i++) 5824 if (i == format_num) 5825 { 5826 check_function_arguments_recurse (callback, ctx, 5827 TREE_VALUE (inner_args), 5828 param_num); 5829 found_format_arg = true; 5830 break; 5831 } 5832 } 5833 5834 /* If we found a format_arg attribute and did a recursive check, 5835 we are done with checking this argument. Otherwise, we continue 5836 and this will be considered a non-literal. */ 5837 if (found_format_arg) 5838 return; 5839 } 5840 5841 if (TREE_CODE (param) == COND_EXPR) 5842 { 5843 /* Check both halves of the conditional expression. */ 5844 check_function_arguments_recurse (callback, ctx, 5845 TREE_OPERAND (param, 1), param_num); 5846 check_function_arguments_recurse (callback, ctx, 5847 TREE_OPERAND (param, 2), param_num); 5848 return; 5849 } 5850 5851 (*callback) (ctx, param, param_num); 5852} 5853 5854/* Function to help qsort sort FIELD_DECLs by name order. */ 5855 5856int 5857field_decl_cmp (const void *x_p, const void *y_p) 5858{ 5859 const tree *const x = (const tree *const) x_p; 5860 const tree *const y = (const tree *const) y_p; 5861 5862 if (DECL_NAME (*x) == DECL_NAME (*y)) 5863 /* A nontype is "greater" than a type. */ 5864 return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL); 5865 if (DECL_NAME (*x) == NULL_TREE) 5866 return -1; 5867 if (DECL_NAME (*y) == NULL_TREE) 5868 return 1; 5869 if (DECL_NAME (*x) < DECL_NAME (*y)) 5870 return -1; 5871 return 1; 5872} 5873 5874static struct { 5875 gt_pointer_operator new_value; 5876 void *cookie; 5877} resort_data; 5878 5879/* This routine compares two fields like field_decl_cmp but using the 5880pointer operator in resort_data. */ 5881 5882static int 5883resort_field_decl_cmp (const void *x_p, const void *y_p) 5884{ 5885 const tree *const x = (const tree *const) x_p; 5886 const tree *const y = (const tree *const) y_p; 5887 5888 if (DECL_NAME (*x) == DECL_NAME (*y)) 5889 /* A nontype is "greater" than a type. */ 5890 return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL); 5891 if (DECL_NAME (*x) == NULL_TREE) 5892 return -1; 5893 if (DECL_NAME (*y) == NULL_TREE) 5894 return 1; 5895 { 5896 tree d1 = DECL_NAME (*x); 5897 tree d2 = DECL_NAME (*y); 5898 resort_data.new_value (&d1, resort_data.cookie); 5899 resort_data.new_value (&d2, resort_data.cookie); 5900 if (d1 < d2) 5901 return -1; 5902 } 5903 return 1; 5904} 5905 5906/* Resort DECL_SORTED_FIELDS because pointers have been reordered. */ 5907 5908void 5909resort_sorted_fields (void *obj, 5910 void * ARG_UNUSED (orig_obj), 5911 gt_pointer_operator new_value, 5912 void *cookie) 5913{ 5914 struct sorted_fields_type *sf = (struct sorted_fields_type *) obj; 5915 resort_data.new_value = new_value; 5916 resort_data.cookie = cookie; 5917 qsort (&sf->elts[0], sf->len, sizeof (tree), 5918 resort_field_decl_cmp); 5919} 5920 5921/* Subroutine of c_parse_error. 5922 Return the result of concatenating LHS and RHS. RHS is really 5923 a string literal, its first character is indicated by RHS_START and 5924 RHS_SIZE is its length (including the terminating NUL character). 5925 5926 The caller is responsible for deleting the returned pointer. */ 5927 5928static char * 5929catenate_strings (const char *lhs, const char *rhs_start, int rhs_size) 5930{ 5931 const int lhs_size = strlen (lhs); 5932 char *result = XNEWVEC (char, lhs_size + rhs_size); 5933 strncpy (result, lhs, lhs_size); 5934 strncpy (result + lhs_size, rhs_start, rhs_size); 5935 return result; 5936} 5937 5938/* Issue the error given by GMSGID, indicating that it occurred before 5939 TOKEN, which had the associated VALUE. */ 5940 5941void 5942c_parse_error (const char *gmsgid, enum cpp_ttype token, tree value) 5943{ 5944#define catenate_messages(M1, M2) catenate_strings ((M1), (M2), sizeof (M2)) 5945 5946 char *message = NULL; 5947 5948 if (token == CPP_EOF) 5949 message = catenate_messages (gmsgid, " at end of input"); 5950 else if (token == CPP_CHAR || token == CPP_WCHAR) 5951 { 5952 unsigned int val = TREE_INT_CST_LOW (value); 5953 const char *const ell = (token == CPP_CHAR) ? "" : "L"; 5954 if (val <= UCHAR_MAX && ISGRAPH (val)) 5955 message = catenate_messages (gmsgid, " before %s'%c'"); 5956 else 5957 message = catenate_messages (gmsgid, " before %s'\\x%x'"); 5958 5959 error (message, ell, val); 5960 free (message); 5961 message = NULL; 5962 } 5963 else if (token == CPP_STRING || token == CPP_WSTRING) 5964 message = catenate_messages (gmsgid, " before string constant"); 5965 else if (token == CPP_NUMBER) 5966 message = catenate_messages (gmsgid, " before numeric constant"); 5967 else if (token == CPP_NAME) 5968 { 5969 message = catenate_messages (gmsgid, " before %qE"); 5970 error (message, value); 5971 free (message); 5972 message = NULL; 5973 } 5974 else if (token == CPP_PRAGMA) 5975 message = catenate_messages (gmsgid, " before %<#pragma%>"); 5976 else if (token == CPP_PRAGMA_EOL) 5977 message = catenate_messages (gmsgid, " before end of line"); 5978 else if (token < N_TTYPES) 5979 { 5980 message = catenate_messages (gmsgid, " before %qs token"); 5981 error (message, cpp_type2name (token)); 5982 free (message); 5983 message = NULL; 5984 } 5985 else 5986 error (gmsgid, ""); 5987 5988 if (message) 5989 { 5990 error (message, ""); 5991 free (message); 5992 } 5993#undef catenate_messages 5994} 5995 5996/* Walk a gimplified function and warn for functions whose return value is 5997 ignored and attribute((warn_unused_result)) is set. This is done before 5998 inlining, so we don't have to worry about that. */ 5999 6000void 6001c_warn_unused_result (tree *top_p) 6002{ 6003 tree t = *top_p; 6004 tree_stmt_iterator i; 6005 tree fdecl, ftype; 6006 6007 switch (TREE_CODE (t)) 6008 { 6009 case STATEMENT_LIST: 6010 for (i = tsi_start (*top_p); !tsi_end_p (i); tsi_next (&i)) 6011 c_warn_unused_result (tsi_stmt_ptr (i)); 6012 break; 6013 6014 case COND_EXPR: 6015 c_warn_unused_result (&COND_EXPR_THEN (t)); 6016 c_warn_unused_result (&COND_EXPR_ELSE (t)); 6017 break; 6018 case BIND_EXPR: 6019 c_warn_unused_result (&BIND_EXPR_BODY (t)); 6020 break; 6021 case TRY_FINALLY_EXPR: 6022 case TRY_CATCH_EXPR: 6023 c_warn_unused_result (&TREE_OPERAND (t, 0)); 6024 c_warn_unused_result (&TREE_OPERAND (t, 1)); 6025 break; 6026 case CATCH_EXPR: 6027 c_warn_unused_result (&CATCH_BODY (t)); 6028 break; 6029 case EH_FILTER_EXPR: 6030 c_warn_unused_result (&EH_FILTER_FAILURE (t)); 6031 break; 6032 6033 case CALL_EXPR: 6034 if (TREE_USED (t)) 6035 break; 6036 6037 /* This is a naked call, as opposed to a CALL_EXPR nested inside 6038 a MODIFY_EXPR. All calls whose value is ignored should be 6039 represented like this. Look for the attribute. */ 6040 fdecl = get_callee_fndecl (t); 6041 if (fdecl) 6042 ftype = TREE_TYPE (fdecl); 6043 else 6044 { 6045 ftype = TREE_TYPE (TREE_OPERAND (t, 0)); 6046 /* Look past pointer-to-function to the function type itself. */ 6047 ftype = TREE_TYPE (ftype); 6048 } 6049 6050 if (lookup_attribute ("warn_unused_result", TYPE_ATTRIBUTES (ftype))) 6051 { 6052 if (fdecl) 6053 warning (0, "%Hignoring return value of %qD, " 6054 "declared with attribute warn_unused_result", 6055 EXPR_LOCUS (t), fdecl); 6056 else 6057 warning (0, "%Hignoring return value of function " 6058 "declared with attribute warn_unused_result", 6059 EXPR_LOCUS (t)); 6060 } 6061 break; 6062 6063 default: 6064 /* Not a container, not a call, or a call whose value is used. */ 6065 break; 6066 } 6067} 6068 6069/* Convert a character from the host to the target execution character 6070 set. cpplib handles this, mostly. */ 6071 6072HOST_WIDE_INT 6073c_common_to_target_charset (HOST_WIDE_INT c) 6074{ 6075 /* Character constants in GCC proper are sign-extended under -fsigned-char, 6076 zero-extended under -fno-signed-char. cpplib insists that characters 6077 and character constants are always unsigned. Hence we must convert 6078 back and forth. */ 6079 cppchar_t uc = ((cppchar_t)c) & ((((cppchar_t)1) << CHAR_BIT)-1); 6080 6081 uc = cpp_host_to_exec_charset (parse_in, uc); 6082 6083 if (flag_signed_char) 6084 return ((HOST_WIDE_INT)uc) << (HOST_BITS_PER_WIDE_INT - CHAR_TYPE_SIZE) 6085 >> (HOST_BITS_PER_WIDE_INT - CHAR_TYPE_SIZE); 6086 else 6087 return uc; 6088} 6089 6090/* Build the result of __builtin_offsetof. EXPR is a nested sequence of 6091 component references, with STOP_REF, or alternatively an INDIRECT_REF of 6092 NULL, at the bottom; much like the traditional rendering of offsetof as a 6093 macro. Returns the folded and properly cast result. */ 6094 6095static tree 6096fold_offsetof_1 (tree expr, tree stop_ref) 6097{ 6098 enum tree_code code = PLUS_EXPR; 6099 tree base, off, t; 6100 6101 if (expr == stop_ref && TREE_CODE (expr) != ERROR_MARK) 6102 return size_zero_node; 6103 6104 switch (TREE_CODE (expr)) 6105 { 6106 case ERROR_MARK: 6107 return expr; 6108 6109 case VAR_DECL: 6110 error ("cannot apply %<offsetof%> to static data member %qD", expr); 6111 return error_mark_node; 6112 6113 case CALL_EXPR: 6114 error ("cannot apply %<offsetof%> when %<operator[]%> is overloaded"); 6115 return error_mark_node; 6116 6117 case INTEGER_CST: 6118 gcc_assert (integer_zerop (expr)); 6119 return size_zero_node; 6120 6121 case NOP_EXPR: 6122 case INDIRECT_REF: 6123 base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref); 6124 gcc_assert (base == error_mark_node || base == size_zero_node); 6125 return base; 6126 6127 case COMPONENT_REF: 6128 base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref); 6129 if (base == error_mark_node) 6130 return base; 6131 6132 t = TREE_OPERAND (expr, 1); 6133 if (DECL_C_BIT_FIELD (t)) 6134 { 6135 error ("attempt to take address of bit-field structure " 6136 "member %qD", t); 6137 return error_mark_node; 6138 } 6139 off = size_binop (PLUS_EXPR, DECL_FIELD_OFFSET (t), 6140 size_int (tree_low_cst (DECL_FIELD_BIT_OFFSET (t), 1) 6141 / BITS_PER_UNIT)); 6142 break; 6143 6144 case ARRAY_REF: 6145 base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref); 6146 if (base == error_mark_node) 6147 return base; 6148 6149 t = TREE_OPERAND (expr, 1); 6150 if (TREE_CODE (t) == INTEGER_CST && tree_int_cst_sgn (t) < 0) 6151 { 6152 code = MINUS_EXPR; 6153 t = fold_build1 (NEGATE_EXPR, TREE_TYPE (t), t); 6154 } 6155 t = convert (sizetype, t); 6156 off = size_binop (MULT_EXPR, TYPE_SIZE_UNIT (TREE_TYPE (expr)), t); 6157 break; 6158 6159 case COMPOUND_EXPR: 6160 /* Handle static members of volatile structs. */ 6161 t = TREE_OPERAND (expr, 1); 6162 gcc_assert (TREE_CODE (t) == VAR_DECL); 6163 return fold_offsetof_1 (t, stop_ref); 6164 6165 default: 6166 gcc_unreachable (); 6167 } 6168 6169 return size_binop (code, base, off); 6170} 6171 6172tree 6173fold_offsetof (tree expr, tree stop_ref) 6174{ 6175 /* Convert back from the internal sizetype to size_t. */ 6176 return convert (size_type_node, fold_offsetof_1 (expr, stop_ref)); 6177} 6178 6179/* Print an error message for an invalid lvalue. USE says 6180 how the lvalue is being used and so selects the error message. */ 6181 6182void 6183lvalue_error (enum lvalue_use use) 6184{ 6185 switch (use) 6186 { 6187 case lv_assign: 6188 error ("lvalue required as left operand of assignment"); 6189 break; 6190 case lv_increment: 6191 error ("lvalue required as increment operand"); 6192 break; 6193 case lv_decrement: 6194 error ("lvalue required as decrement operand"); 6195 break; 6196 case lv_addressof: 6197 error ("lvalue required as unary %<&%> operand"); 6198 break; 6199 case lv_asm: 6200 error ("lvalue required in asm statement"); 6201 break; 6202 default: 6203 gcc_unreachable (); 6204 } 6205} 6206 6207/* *PTYPE is an incomplete array. Complete it with a domain based on 6208 INITIAL_VALUE. If INITIAL_VALUE is not present, use 1 if DO_DEFAULT 6209 is true. Return 0 if successful, 1 if INITIAL_VALUE can't be deciphered, 6210 2 if INITIAL_VALUE was NULL, and 3 if INITIAL_VALUE was empty. */ 6211 6212int 6213complete_array_type (tree *ptype, tree initial_value, bool do_default) 6214{ 6215 tree maxindex, type, main_type, elt, unqual_elt; 6216 int failure = 0, quals; 6217 6218 maxindex = size_zero_node; 6219 if (initial_value) 6220 { 6221 if (TREE_CODE (initial_value) == STRING_CST) 6222 { 6223 int eltsize 6224 = int_size_in_bytes (TREE_TYPE (TREE_TYPE (initial_value))); 6225 maxindex = size_int (TREE_STRING_LENGTH (initial_value)/eltsize - 1); 6226 } 6227 else if (TREE_CODE (initial_value) == CONSTRUCTOR) 6228 { 6229 VEC(constructor_elt,gc) *v = CONSTRUCTOR_ELTS (initial_value); 6230 6231 if (VEC_empty (constructor_elt, v)) 6232 { 6233 if (pedantic) 6234 failure = 3; 6235 maxindex = integer_minus_one_node; 6236 } 6237 else 6238 { 6239 tree curindex; 6240 unsigned HOST_WIDE_INT cnt; 6241 constructor_elt *ce; 6242 6243 if (VEC_index (constructor_elt, v, 0)->index) 6244 maxindex = fold_convert (sizetype, 6245 VEC_index (constructor_elt, 6246 v, 0)->index); 6247 curindex = maxindex; 6248 6249 for (cnt = 1; 6250 VEC_iterate (constructor_elt, v, cnt, ce); 6251 cnt++) 6252 { 6253 if (ce->index) 6254 curindex = fold_convert (sizetype, ce->index); 6255 else 6256 curindex = size_binop (PLUS_EXPR, curindex, size_one_node); 6257 6258 if (tree_int_cst_lt (maxindex, curindex)) 6259 maxindex = curindex; 6260 } 6261 } 6262 } 6263 else 6264 { 6265 /* Make an error message unless that happened already. */ 6266 if (initial_value != error_mark_node) 6267 failure = 1; 6268 } 6269 } 6270 else 6271 { 6272 failure = 2; 6273 if (!do_default) 6274 return failure; 6275 } 6276 6277 type = *ptype; 6278 elt = TREE_TYPE (type); 6279 quals = TYPE_QUALS (strip_array_types (elt)); 6280 if (quals == 0) 6281 unqual_elt = elt; 6282 else 6283 unqual_elt = c_build_qualified_type (elt, TYPE_UNQUALIFIED); 6284 6285 /* Using build_distinct_type_copy and modifying things afterward instead 6286 of using build_array_type to create a new type preserves all of the 6287 TYPE_LANG_FLAG_? bits that the front end may have set. */ 6288 main_type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type)); 6289 TREE_TYPE (main_type) = unqual_elt; 6290 TYPE_DOMAIN (main_type) = build_index_type (maxindex); 6291 layout_type (main_type); 6292 6293 if (quals == 0) 6294 type = main_type; 6295 else 6296 type = c_build_qualified_type (main_type, quals); 6297 6298 *ptype = type; 6299 return failure; 6300} 6301 6302 6303/* Used to help initialize the builtin-types.def table. When a type of 6304 the correct size doesn't exist, use error_mark_node instead of NULL. 6305 The later results in segfaults even when a decl using the type doesn't 6306 get invoked. */ 6307 6308tree 6309builtin_type_for_size (int size, bool unsignedp) 6310{ 6311 tree type = lang_hooks.types.type_for_size (size, unsignedp); 6312 return type ? type : error_mark_node; 6313} 6314 6315/* A helper function for resolve_overloaded_builtin in resolving the 6316 overloaded __sync_ builtins. Returns a positive power of 2 if the 6317 first operand of PARAMS is a pointer to a supported data type. 6318 Returns 0 if an error is encountered. */ 6319 6320static int 6321sync_resolve_size (tree function, tree params) 6322{ 6323 tree type; 6324 int size; 6325 6326 if (params == NULL) 6327 { 6328 error ("too few arguments to function %qE", function); 6329 return 0; 6330 } 6331 6332 type = TREE_TYPE (TREE_VALUE (params)); 6333 if (TREE_CODE (type) != POINTER_TYPE) 6334 goto incompatible; 6335 6336 type = TREE_TYPE (type); 6337 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type)) 6338 goto incompatible; 6339 6340 size = tree_low_cst (TYPE_SIZE_UNIT (type), 1); 6341 if (size == 1 || size == 2 || size == 4 || size == 8 || size == 16) 6342 return size; 6343 6344 incompatible: 6345 error ("incompatible type for argument %d of %qE", 1, function); 6346 return 0; 6347} 6348 6349/* A helper function for resolve_overloaded_builtin. Adds casts to 6350 PARAMS to make arguments match up with those of FUNCTION. Drops 6351 the variadic arguments at the end. Returns false if some error 6352 was encountered; true on success. */ 6353 6354static bool 6355sync_resolve_params (tree orig_function, tree function, tree params) 6356{ 6357 tree arg_types = TYPE_ARG_TYPES (TREE_TYPE (function)); 6358 tree ptype; 6359 int number; 6360 6361 /* We've declared the implementation functions to use "volatile void *" 6362 as the pointer parameter, so we shouldn't get any complaints from the 6363 call to check_function_arguments what ever type the user used. */ 6364 arg_types = TREE_CHAIN (arg_types); 6365 ptype = TREE_TYPE (TREE_TYPE (TREE_VALUE (params))); 6366 number = 2; 6367 6368 /* For the rest of the values, we need to cast these to FTYPE, so that we 6369 don't get warnings for passing pointer types, etc. */ 6370 while (arg_types != void_list_node) 6371 { 6372 tree val; 6373 6374 params = TREE_CHAIN (params); 6375 if (params == NULL) 6376 { 6377 error ("too few arguments to function %qE", orig_function); 6378 return false; 6379 } 6380 6381 /* ??? Ideally for the first conversion we'd use convert_for_assignment 6382 so that we get warnings for anything that doesn't match the pointer 6383 type. This isn't portable across the C and C++ front ends atm. */ 6384 val = TREE_VALUE (params); 6385 val = convert (ptype, val); 6386 val = convert (TREE_VALUE (arg_types), val); 6387 TREE_VALUE (params) = val; 6388 6389 arg_types = TREE_CHAIN (arg_types); 6390 number++; 6391 } 6392 6393 /* The definition of these primitives is variadic, with the remaining 6394 being "an optional list of variables protected by the memory barrier". 6395 No clue what that's supposed to mean, precisely, but we consider all 6396 call-clobbered variables to be protected so we're safe. */ 6397 TREE_CHAIN (params) = NULL; 6398 6399 return true; 6400} 6401 6402/* A helper function for resolve_overloaded_builtin. Adds a cast to 6403 RESULT to make it match the type of the first pointer argument in 6404 PARAMS. */ 6405 6406static tree 6407sync_resolve_return (tree params, tree result) 6408{ 6409 tree ptype = TREE_TYPE (TREE_TYPE (TREE_VALUE (params))); 6410 ptype = TYPE_MAIN_VARIANT (ptype); 6411 return convert (ptype, result); 6412} 6413 6414/* Some builtin functions are placeholders for other expressions. This 6415 function should be called immediately after parsing the call expression 6416 before surrounding code has committed to the type of the expression. 6417 6418 FUNCTION is the DECL that has been invoked; it is known to be a builtin. 6419 PARAMS is the argument list for the call. The return value is non-null 6420 when expansion is complete, and null if normal processing should 6421 continue. */ 6422 6423tree 6424resolve_overloaded_builtin (tree function, tree params) 6425{ 6426 enum built_in_function orig_code = DECL_FUNCTION_CODE (function); 6427 switch (DECL_BUILT_IN_CLASS (function)) 6428 { 6429 case BUILT_IN_NORMAL: 6430 break; 6431 case BUILT_IN_MD: 6432 if (targetm.resolve_overloaded_builtin) 6433 return targetm.resolve_overloaded_builtin (function, params); 6434 else 6435 return NULL_TREE; 6436 default: 6437 return NULL_TREE; 6438 } 6439 6440 /* Handle BUILT_IN_NORMAL here. */ 6441 switch (orig_code) 6442 { 6443 case BUILT_IN_FETCH_AND_ADD_N: 6444 case BUILT_IN_FETCH_AND_SUB_N: 6445 case BUILT_IN_FETCH_AND_OR_N: 6446 case BUILT_IN_FETCH_AND_AND_N: 6447 case BUILT_IN_FETCH_AND_XOR_N: 6448 case BUILT_IN_FETCH_AND_NAND_N: 6449 case BUILT_IN_ADD_AND_FETCH_N: 6450 case BUILT_IN_SUB_AND_FETCH_N: 6451 case BUILT_IN_OR_AND_FETCH_N: 6452 case BUILT_IN_AND_AND_FETCH_N: 6453 case BUILT_IN_XOR_AND_FETCH_N: 6454 case BUILT_IN_NAND_AND_FETCH_N: 6455 case BUILT_IN_BOOL_COMPARE_AND_SWAP_N: 6456 case BUILT_IN_VAL_COMPARE_AND_SWAP_N: 6457 case BUILT_IN_LOCK_TEST_AND_SET_N: 6458 case BUILT_IN_LOCK_RELEASE_N: 6459 { 6460 int n = sync_resolve_size (function, params); 6461 tree new_function, result; 6462 6463 if (n == 0) 6464 return error_mark_node; 6465 6466 new_function = built_in_decls[orig_code + exact_log2 (n) + 1]; 6467 if (!sync_resolve_params (function, new_function, params)) 6468 return error_mark_node; 6469 6470 result = build_function_call (new_function, params); 6471 if (orig_code != BUILT_IN_BOOL_COMPARE_AND_SWAP_N 6472 && orig_code != BUILT_IN_LOCK_RELEASE_N) 6473 result = sync_resolve_return (params, result); 6474 6475 return result; 6476 } 6477 6478 default: 6479 return NULL_TREE; 6480 } 6481} 6482 6483/* Ignoring their sign, return true if two scalar types are the same. */ 6484bool 6485same_scalar_type_ignoring_signedness (tree t1, tree t2) 6486{ 6487 enum tree_code c1 = TREE_CODE (t1), c2 = TREE_CODE (t2); 6488 6489 gcc_assert ((c1 == INTEGER_TYPE || c1 == REAL_TYPE) 6490 && (c2 == INTEGER_TYPE || c2 == REAL_TYPE)); 6491 6492 /* Equality works here because c_common_signed_type uses 6493 TYPE_MAIN_VARIANT. */ 6494 return lang_hooks.types.signed_type (t1) 6495 == lang_hooks.types.signed_type (t2); 6496} 6497 6498/* Check for missing format attributes on function pointers. LTYPE is 6499 the new type or left-hand side type. RTYPE is the old type or 6500 right-hand side type. Returns TRUE if LTYPE is missing the desired 6501 attribute. */ 6502 6503bool 6504check_missing_format_attribute (tree ltype, tree rtype) 6505{ 6506 tree const ttr = TREE_TYPE (rtype), ttl = TREE_TYPE (ltype); 6507 tree ra; 6508 6509 for (ra = TYPE_ATTRIBUTES (ttr); ra; ra = TREE_CHAIN (ra)) 6510 if (is_attribute_p ("format", TREE_PURPOSE (ra))) 6511 break; 6512 if (ra) 6513 { 6514 tree la; 6515 for (la = TYPE_ATTRIBUTES (ttl); la; la = TREE_CHAIN (la)) 6516 if (is_attribute_p ("format", TREE_PURPOSE (la))) 6517 break; 6518 return !la; 6519 } 6520 else 6521 return false; 6522} 6523 6524/* Subscripting with type char is likely to lose on a machine where 6525 chars are signed. So warn on any machine, but optionally. Don't 6526 warn for unsigned char since that type is safe. Don't warn for 6527 signed char because anyone who uses that must have done so 6528 deliberately. Furthermore, we reduce the false positive load by 6529 warning only for non-constant value of type char. */ 6530 6531void 6532warn_array_subscript_with_type_char (tree index) 6533{ 6534 if (TYPE_MAIN_VARIANT (TREE_TYPE (index)) == char_type_node 6535 && TREE_CODE (index) != INTEGER_CST) 6536 warning (OPT_Wchar_subscripts, "array subscript has type %<char%>"); 6537} 6538 6539/* Implement -Wparentheses for the unexpected C precedence rules, to 6540 cover cases like x + y << z which readers are likely to 6541 misinterpret. We have seen an expression in which CODE is a binary 6542 operator used to combine expressions headed by CODE_LEFT and 6543 CODE_RIGHT. CODE_LEFT and CODE_RIGHT may be ERROR_MARK, which 6544 means that that side of the expression was not formed using a 6545 binary operator, or it was enclosed in parentheses. */ 6546 6547void 6548warn_about_parentheses (enum tree_code code, enum tree_code code_left, 6549 enum tree_code code_right) 6550{ 6551 if (!warn_parentheses) 6552 return; 6553 6554 if (code == LSHIFT_EXPR || code == RSHIFT_EXPR) 6555 { 6556 if (code_left == PLUS_EXPR || code_left == MINUS_EXPR 6557 || code_right == PLUS_EXPR || code_right == MINUS_EXPR) 6558 warning (OPT_Wparentheses, 6559 "suggest parentheses around + or - inside shift"); 6560 } 6561 6562 if (code == TRUTH_ORIF_EXPR) 6563 { 6564 if (code_left == TRUTH_ANDIF_EXPR 6565 || code_right == TRUTH_ANDIF_EXPR) 6566 warning (OPT_Wparentheses, 6567 "suggest parentheses around && within ||"); 6568 } 6569 6570 if (code == BIT_IOR_EXPR) 6571 { 6572 if (code_left == BIT_AND_EXPR || code_left == BIT_XOR_EXPR 6573 || code_left == PLUS_EXPR || code_left == MINUS_EXPR 6574 || code_right == BIT_AND_EXPR || code_right == BIT_XOR_EXPR 6575 || code_right == PLUS_EXPR || code_right == MINUS_EXPR) 6576 warning (OPT_Wparentheses, 6577 "suggest parentheses around arithmetic in operand of |"); 6578 /* Check cases like x|y==z */ 6579 if (TREE_CODE_CLASS (code_left) == tcc_comparison 6580 || TREE_CODE_CLASS (code_right) == tcc_comparison) 6581 warning (OPT_Wparentheses, 6582 "suggest parentheses around comparison in operand of |"); 6583 } 6584 6585 if (code == BIT_XOR_EXPR) 6586 { 6587 if (code_left == BIT_AND_EXPR 6588 || code_left == PLUS_EXPR || code_left == MINUS_EXPR 6589 || code_right == BIT_AND_EXPR 6590 || code_right == PLUS_EXPR || code_right == MINUS_EXPR) 6591 warning (OPT_Wparentheses, 6592 "suggest parentheses around arithmetic in operand of ^"); 6593 /* Check cases like x^y==z */ 6594 if (TREE_CODE_CLASS (code_left) == tcc_comparison 6595 || TREE_CODE_CLASS (code_right) == tcc_comparison) 6596 warning (OPT_Wparentheses, 6597 "suggest parentheses around comparison in operand of ^"); 6598 } 6599 6600 if (code == BIT_AND_EXPR) 6601 { 6602 if (code_left == PLUS_EXPR || code_left == MINUS_EXPR 6603 || code_right == PLUS_EXPR || code_right == MINUS_EXPR) 6604 warning (OPT_Wparentheses, 6605 "suggest parentheses around + or - in operand of &"); 6606 /* Check cases like x&y==z */ 6607 if (TREE_CODE_CLASS (code_left) == tcc_comparison 6608 || TREE_CODE_CLASS (code_right) == tcc_comparison) 6609 warning (OPT_Wparentheses, 6610 "suggest parentheses around comparison in operand of &"); 6611 } 6612 6613 /* Similarly, check for cases like 1<=i<=10 that are probably errors. */ 6614 if (TREE_CODE_CLASS (code) == tcc_comparison 6615 && (TREE_CODE_CLASS (code_left) == tcc_comparison 6616 || TREE_CODE_CLASS (code_right) == tcc_comparison)) 6617 warning (OPT_Wparentheses, "comparisons like X<=Y<=Z do not " 6618 "have their mathematical meaning"); 6619} 6620 6621 6622#include "gt-c-common.h" 6623