c-common.c revision 259694
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. */ 1992 1993void 1994binary_op_error (enum tree_code code) 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", opname); 2046} 2047 2048/* Subroutine of build_binary_op, used for comparison operations. 2049 See if the operands have both been converted from subword integer types 2050 and, if so, perhaps change them both back to their original type. 2051 This function is also responsible for converting the two operands 2052 to the proper common type for comparison. 2053 2054 The arguments of this function are all pointers to local variables 2055 of build_binary_op: OP0_PTR is &OP0, OP1_PTR is &OP1, 2056 RESTYPE_PTR is &RESULT_TYPE and RESCODE_PTR is &RESULTCODE. 2057 2058 If this function returns nonzero, it means that the comparison has 2059 a constant value. What this function returns is an expression for 2060 that value. */ 2061 2062tree 2063shorten_compare (tree *op0_ptr, tree *op1_ptr, tree *restype_ptr, 2064 enum tree_code *rescode_ptr) 2065{ 2066 tree type; 2067 tree op0 = *op0_ptr; 2068 tree op1 = *op1_ptr; 2069 int unsignedp0, unsignedp1; 2070 int real1, real2; 2071 tree primop0, primop1; 2072 enum tree_code code = *rescode_ptr; 2073 2074 /* Throw away any conversions to wider types 2075 already present in the operands. */ 2076 2077 primop0 = get_narrower (op0, &unsignedp0); 2078 primop1 = get_narrower (op1, &unsignedp1); 2079 2080 /* Handle the case that OP0 does not *contain* a conversion 2081 but it *requires* conversion to FINAL_TYPE. */ 2082 2083 if (op0 == primop0 && TREE_TYPE (op0) != *restype_ptr) 2084 unsignedp0 = TYPE_UNSIGNED (TREE_TYPE (op0)); 2085 if (op1 == primop1 && TREE_TYPE (op1) != *restype_ptr) 2086 unsignedp1 = TYPE_UNSIGNED (TREE_TYPE (op1)); 2087 2088 /* If one of the operands must be floated, we cannot optimize. */ 2089 real1 = TREE_CODE (TREE_TYPE (primop0)) == REAL_TYPE; 2090 real2 = TREE_CODE (TREE_TYPE (primop1)) == REAL_TYPE; 2091 2092 /* If first arg is constant, swap the args (changing operation 2093 so value is preserved), for canonicalization. Don't do this if 2094 the second arg is 0. */ 2095 2096 if (TREE_CONSTANT (primop0) 2097 && !integer_zerop (primop1) && !real_zerop (primop1)) 2098 { 2099 tree tem = primop0; 2100 int temi = unsignedp0; 2101 primop0 = primop1; 2102 primop1 = tem; 2103 tem = op0; 2104 op0 = op1; 2105 op1 = tem; 2106 *op0_ptr = op0; 2107 *op1_ptr = op1; 2108 unsignedp0 = unsignedp1; 2109 unsignedp1 = temi; 2110 temi = real1; 2111 real1 = real2; 2112 real2 = temi; 2113 2114 switch (code) 2115 { 2116 case LT_EXPR: 2117 code = GT_EXPR; 2118 break; 2119 case GT_EXPR: 2120 code = LT_EXPR; 2121 break; 2122 case LE_EXPR: 2123 code = GE_EXPR; 2124 break; 2125 case GE_EXPR: 2126 code = LE_EXPR; 2127 break; 2128 default: 2129 break; 2130 } 2131 *rescode_ptr = code; 2132 } 2133 2134 /* If comparing an integer against a constant more bits wide, 2135 maybe we can deduce a value of 1 or 0 independent of the data. 2136 Or else truncate the constant now 2137 rather than extend the variable at run time. 2138 2139 This is only interesting if the constant is the wider arg. 2140 Also, it is not safe if the constant is unsigned and the 2141 variable arg is signed, since in this case the variable 2142 would be sign-extended and then regarded as unsigned. 2143 Our technique fails in this case because the lowest/highest 2144 possible unsigned results don't follow naturally from the 2145 lowest/highest possible values of the variable operand. 2146 For just EQ_EXPR and NE_EXPR there is another technique that 2147 could be used: see if the constant can be faithfully represented 2148 in the other operand's type, by truncating it and reextending it 2149 and see if that preserves the constant's value. */ 2150 2151 if (!real1 && !real2 2152 && TREE_CODE (primop1) == INTEGER_CST 2153 && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr)) 2154 { 2155 int min_gt, max_gt, min_lt, max_lt; 2156 tree maxval, minval; 2157 /* 1 if comparison is nominally unsigned. */ 2158 int unsignedp = TYPE_UNSIGNED (*restype_ptr); 2159 tree val; 2160 2161 type = c_common_signed_or_unsigned_type (unsignedp0, 2162 TREE_TYPE (primop0)); 2163 2164 maxval = TYPE_MAX_VALUE (type); 2165 minval = TYPE_MIN_VALUE (type); 2166 2167 if (unsignedp && !unsignedp0) 2168 *restype_ptr = c_common_signed_type (*restype_ptr); 2169 2170 if (TREE_TYPE (primop1) != *restype_ptr) 2171 { 2172 /* Convert primop1 to target type, but do not introduce 2173 additional overflow. We know primop1 is an int_cst. */ 2174 tree tmp = build_int_cst_wide (*restype_ptr, 2175 TREE_INT_CST_LOW (primop1), 2176 TREE_INT_CST_HIGH (primop1)); 2177 2178 primop1 = force_fit_type (tmp, 0, TREE_OVERFLOW (primop1), 2179 TREE_CONSTANT_OVERFLOW (primop1)); 2180 } 2181 if (type != *restype_ptr) 2182 { 2183 minval = convert (*restype_ptr, minval); 2184 maxval = convert (*restype_ptr, maxval); 2185 } 2186 2187 if (unsignedp && unsignedp0) 2188 { 2189 min_gt = INT_CST_LT_UNSIGNED (primop1, minval); 2190 max_gt = INT_CST_LT_UNSIGNED (primop1, maxval); 2191 min_lt = INT_CST_LT_UNSIGNED (minval, primop1); 2192 max_lt = INT_CST_LT_UNSIGNED (maxval, primop1); 2193 } 2194 else 2195 { 2196 min_gt = INT_CST_LT (primop1, minval); 2197 max_gt = INT_CST_LT (primop1, maxval); 2198 min_lt = INT_CST_LT (minval, primop1); 2199 max_lt = INT_CST_LT (maxval, primop1); 2200 } 2201 2202 val = 0; 2203 /* This used to be a switch, but Genix compiler can't handle that. */ 2204 if (code == NE_EXPR) 2205 { 2206 if (max_lt || min_gt) 2207 val = truthvalue_true_node; 2208 } 2209 else if (code == EQ_EXPR) 2210 { 2211 if (max_lt || min_gt) 2212 val = truthvalue_false_node; 2213 } 2214 else if (code == LT_EXPR) 2215 { 2216 if (max_lt) 2217 val = truthvalue_true_node; 2218 if (!min_lt) 2219 val = truthvalue_false_node; 2220 } 2221 else if (code == GT_EXPR) 2222 { 2223 if (min_gt) 2224 val = truthvalue_true_node; 2225 if (!max_gt) 2226 val = truthvalue_false_node; 2227 } 2228 else if (code == LE_EXPR) 2229 { 2230 if (!max_gt) 2231 val = truthvalue_true_node; 2232 if (min_gt) 2233 val = truthvalue_false_node; 2234 } 2235 else if (code == GE_EXPR) 2236 { 2237 if (!min_lt) 2238 val = truthvalue_true_node; 2239 if (max_lt) 2240 val = truthvalue_false_node; 2241 } 2242 2243 /* If primop0 was sign-extended and unsigned comparison specd, 2244 we did a signed comparison above using the signed type bounds. 2245 But the comparison we output must be unsigned. 2246 2247 Also, for inequalities, VAL is no good; but if the signed 2248 comparison had *any* fixed result, it follows that the 2249 unsigned comparison just tests the sign in reverse 2250 (positive values are LE, negative ones GE). 2251 So we can generate an unsigned comparison 2252 against an extreme value of the signed type. */ 2253 2254 if (unsignedp && !unsignedp0) 2255 { 2256 if (val != 0) 2257 switch (code) 2258 { 2259 case LT_EXPR: 2260 case GE_EXPR: 2261 primop1 = TYPE_MIN_VALUE (type); 2262 val = 0; 2263 break; 2264 2265 case LE_EXPR: 2266 case GT_EXPR: 2267 primop1 = TYPE_MAX_VALUE (type); 2268 val = 0; 2269 break; 2270 2271 default: 2272 break; 2273 } 2274 type = c_common_unsigned_type (type); 2275 } 2276 2277 if (TREE_CODE (primop0) != INTEGER_CST) 2278 { 2279 if (val == truthvalue_false_node) 2280 warning (0, "comparison is always false due to limited range of data type"); 2281 if (val == truthvalue_true_node) 2282 warning (0, "comparison is always true due to limited range of data type"); 2283 } 2284 2285 if (val != 0) 2286 { 2287 /* Don't forget to evaluate PRIMOP0 if it has side effects. */ 2288 if (TREE_SIDE_EFFECTS (primop0)) 2289 return build2 (COMPOUND_EXPR, TREE_TYPE (val), primop0, val); 2290 return val; 2291 } 2292 2293 /* Value is not predetermined, but do the comparison 2294 in the type of the operand that is not constant. 2295 TYPE is already properly set. */ 2296 } 2297 2298 /* If either arg is decimal float and the other is float, find the 2299 proper common type to use for comparison. */ 2300 else if (real1 && real2 2301 && (DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (primop0))) 2302 || DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (primop1))))) 2303 type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1)); 2304 2305 else if (real1 && real2 2306 && (TYPE_PRECISION (TREE_TYPE (primop0)) 2307 == TYPE_PRECISION (TREE_TYPE (primop1)))) 2308 type = TREE_TYPE (primop0); 2309 2310 /* If args' natural types are both narrower than nominal type 2311 and both extend in the same manner, compare them 2312 in the type of the wider arg. 2313 Otherwise must actually extend both to the nominal 2314 common type lest different ways of extending 2315 alter the result. 2316 (eg, (short)-1 == (unsigned short)-1 should be 0.) */ 2317 2318 else if (unsignedp0 == unsignedp1 && real1 == real2 2319 && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr) 2320 && TYPE_PRECISION (TREE_TYPE (primop1)) < TYPE_PRECISION (*restype_ptr)) 2321 { 2322 type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1)); 2323 type = c_common_signed_or_unsigned_type (unsignedp0 2324 || TYPE_UNSIGNED (*restype_ptr), 2325 type); 2326 /* Make sure shorter operand is extended the right way 2327 to match the longer operand. */ 2328 primop0 2329 = convert (c_common_signed_or_unsigned_type (unsignedp0, 2330 TREE_TYPE (primop0)), 2331 primop0); 2332 primop1 2333 = convert (c_common_signed_or_unsigned_type (unsignedp1, 2334 TREE_TYPE (primop1)), 2335 primop1); 2336 } 2337 else 2338 { 2339 /* Here we must do the comparison on the nominal type 2340 using the args exactly as we received them. */ 2341 type = *restype_ptr; 2342 primop0 = op0; 2343 primop1 = op1; 2344 2345 if (!real1 && !real2 && integer_zerop (primop1) 2346 && TYPE_UNSIGNED (*restype_ptr)) 2347 { 2348 tree value = 0; 2349 switch (code) 2350 { 2351 case GE_EXPR: 2352 /* All unsigned values are >= 0, so we warn if extra warnings 2353 are requested. However, if OP0 is a constant that is 2354 >= 0, the signedness of the comparison isn't an issue, 2355 so suppress the warning. */ 2356 if (extra_warnings && !in_system_header 2357 && !(TREE_CODE (primop0) == INTEGER_CST 2358 && !TREE_OVERFLOW (convert (c_common_signed_type (type), 2359 primop0)))) 2360 warning (0, "comparison of unsigned expression >= 0 is always true"); 2361 value = truthvalue_true_node; 2362 break; 2363 2364 case LT_EXPR: 2365 if (extra_warnings && !in_system_header 2366 && !(TREE_CODE (primop0) == INTEGER_CST 2367 && !TREE_OVERFLOW (convert (c_common_signed_type (type), 2368 primop0)))) 2369 warning (0, "comparison of unsigned expression < 0 is always false"); 2370 value = truthvalue_false_node; 2371 break; 2372 2373 default: 2374 break; 2375 } 2376 2377 if (value != 0) 2378 { 2379 /* Don't forget to evaluate PRIMOP0 if it has side effects. */ 2380 if (TREE_SIDE_EFFECTS (primop0)) 2381 return build2 (COMPOUND_EXPR, TREE_TYPE (value), 2382 primop0, value); 2383 return value; 2384 } 2385 } 2386 } 2387 2388 *op0_ptr = convert (type, primop0); 2389 *op1_ptr = convert (type, primop1); 2390 2391 *restype_ptr = truthvalue_type_node; 2392 2393 return 0; 2394} 2395 2396/* Return a tree for the sum or difference (RESULTCODE says which) 2397 of pointer PTROP and integer INTOP. */ 2398 2399tree 2400pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop) 2401{ 2402 tree size_exp, ret; 2403 2404 /* The result is a pointer of the same type that is being added. */ 2405 2406 tree result_type = TREE_TYPE (ptrop); 2407 2408 if (TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE) 2409 { 2410 if (pedantic || warn_pointer_arith) 2411 pedwarn ("pointer of type %<void *%> used in arithmetic"); 2412 size_exp = integer_one_node; 2413 } 2414 else if (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE) 2415 { 2416 if (pedantic || warn_pointer_arith) 2417 pedwarn ("pointer to a function used in arithmetic"); 2418 size_exp = integer_one_node; 2419 } 2420 else if (TREE_CODE (TREE_TYPE (result_type)) == METHOD_TYPE) 2421 { 2422 if (pedantic || warn_pointer_arith) 2423 pedwarn ("pointer to member function used in arithmetic"); 2424 size_exp = integer_one_node; 2425 } 2426 else 2427 size_exp = size_in_bytes (TREE_TYPE (result_type)); 2428 2429 /* We are manipulating pointer values, so we don't need to warn 2430 about relying on undefined signed overflow. We disable the 2431 warning here because we use integer types so fold won't know that 2432 they are really pointers. */ 2433 fold_defer_overflow_warnings (); 2434 2435 /* If what we are about to multiply by the size of the elements 2436 contains a constant term, apply distributive law 2437 and multiply that constant term separately. 2438 This helps produce common subexpressions. */ 2439 2440 if ((TREE_CODE (intop) == PLUS_EXPR || TREE_CODE (intop) == MINUS_EXPR) 2441 && !TREE_CONSTANT (intop) 2442 && TREE_CONSTANT (TREE_OPERAND (intop, 1)) 2443 && TREE_CONSTANT (size_exp) 2444 /* If the constant comes from pointer subtraction, 2445 skip this optimization--it would cause an error. */ 2446 && TREE_CODE (TREE_TYPE (TREE_OPERAND (intop, 0))) == INTEGER_TYPE 2447 /* If the constant is unsigned, and smaller than the pointer size, 2448 then we must skip this optimization. This is because it could cause 2449 an overflow error if the constant is negative but INTOP is not. */ 2450 && (!TYPE_UNSIGNED (TREE_TYPE (intop)) 2451 || (TYPE_PRECISION (TREE_TYPE (intop)) 2452 == TYPE_PRECISION (TREE_TYPE (ptrop))))) 2453 { 2454 enum tree_code subcode = resultcode; 2455 tree int_type = TREE_TYPE (intop); 2456 if (TREE_CODE (intop) == MINUS_EXPR) 2457 subcode = (subcode == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR); 2458 /* Convert both subexpression types to the type of intop, 2459 because weird cases involving pointer arithmetic 2460 can result in a sum or difference with different type args. */ 2461 ptrop = build_binary_op (subcode, ptrop, 2462 convert (int_type, TREE_OPERAND (intop, 1)), 1); 2463 intop = convert (int_type, TREE_OPERAND (intop, 0)); 2464 } 2465 2466 /* Convert the integer argument to a type the same size as sizetype 2467 so the multiply won't overflow spuriously. */ 2468 2469 if (TYPE_PRECISION (TREE_TYPE (intop)) != TYPE_PRECISION (sizetype) 2470 || TYPE_UNSIGNED (TREE_TYPE (intop)) != TYPE_UNSIGNED (sizetype)) 2471 intop = convert (c_common_type_for_size (TYPE_PRECISION (sizetype), 2472 TYPE_UNSIGNED (sizetype)), intop); 2473 2474 /* Replace the integer argument with a suitable product by the object size. 2475 Do this multiplication as signed, then convert to the appropriate 2476 pointer type (actually unsigned integral). */ 2477 2478 intop = convert (result_type, 2479 build_binary_op (MULT_EXPR, intop, 2480 convert (TREE_TYPE (intop), size_exp), 1)); 2481 2482 /* Create the sum or difference. */ 2483 ret = fold_build2 (resultcode, result_type, ptrop, intop); 2484 2485 fold_undefer_and_ignore_overflow_warnings (); 2486 2487 return ret; 2488} 2489 2490/* Prepare expr to be an argument of a TRUTH_NOT_EXPR, 2491 or for an `if' or `while' statement or ?..: exp. It should already 2492 have been validated to be of suitable type; otherwise, a bad 2493 diagnostic may result. 2494 2495 This preparation consists of taking the ordinary 2496 representation of an expression expr and producing a valid tree 2497 boolean expression describing whether expr is nonzero. We could 2498 simply always do build_binary_op (NE_EXPR, expr, truthvalue_false_node, 1), 2499 but we optimize comparisons, &&, ||, and !. 2500 2501 The resulting type should always be `truthvalue_type_node'. */ 2502 2503tree 2504c_common_truthvalue_conversion (tree expr) 2505{ 2506 switch (TREE_CODE (expr)) 2507 { 2508 case EQ_EXPR: case NE_EXPR: case UNEQ_EXPR: case LTGT_EXPR: 2509 case LE_EXPR: case GE_EXPR: case LT_EXPR: case GT_EXPR: 2510 case UNLE_EXPR: case UNGE_EXPR: case UNLT_EXPR: case UNGT_EXPR: 2511 case ORDERED_EXPR: case UNORDERED_EXPR: 2512 if (TREE_TYPE (expr) == truthvalue_type_node) 2513 return expr; 2514 return build2 (TREE_CODE (expr), truthvalue_type_node, 2515 TREE_OPERAND (expr, 0), TREE_OPERAND (expr, 1)); 2516 2517 case TRUTH_ANDIF_EXPR: 2518 case TRUTH_ORIF_EXPR: 2519 case TRUTH_AND_EXPR: 2520 case TRUTH_OR_EXPR: 2521 case TRUTH_XOR_EXPR: 2522 if (TREE_TYPE (expr) == truthvalue_type_node) 2523 return expr; 2524 return build2 (TREE_CODE (expr), truthvalue_type_node, 2525 c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)), 2526 c_common_truthvalue_conversion (TREE_OPERAND (expr, 1))); 2527 2528 case TRUTH_NOT_EXPR: 2529 if (TREE_TYPE (expr) == truthvalue_type_node) 2530 return expr; 2531 return build1 (TREE_CODE (expr), truthvalue_type_node, 2532 c_common_truthvalue_conversion (TREE_OPERAND (expr, 0))); 2533 2534 case ERROR_MARK: 2535 return expr; 2536 2537 case INTEGER_CST: 2538 /* Avoid integer_zerop to ignore TREE_CONSTANT_OVERFLOW. */ 2539 return (TREE_INT_CST_LOW (expr) != 0 || TREE_INT_CST_HIGH (expr) != 0) 2540 ? truthvalue_true_node 2541 : truthvalue_false_node; 2542 2543 case REAL_CST: 2544 return real_compare (NE_EXPR, &TREE_REAL_CST (expr), &dconst0) 2545 ? truthvalue_true_node 2546 : truthvalue_false_node; 2547 2548 case FUNCTION_DECL: 2549 expr = build_unary_op (ADDR_EXPR, expr, 0); 2550 /* Fall through. */ 2551 2552 case ADDR_EXPR: 2553 { 2554 tree inner = TREE_OPERAND (expr, 0); 2555 if (DECL_P (inner) 2556 && (TREE_CODE (inner) == PARM_DECL 2557 || TREE_CODE (inner) == LABEL_DECL 2558 || !DECL_WEAK (inner))) 2559 { 2560 /* Common Ada/Pascal programmer's mistake. We always warn 2561 about this since it is so bad. */ 2562 warning (OPT_Waddress, 2563 "the address of %qD will always evaluate as %<true%>", 2564 inner); 2565 return truthvalue_true_node; 2566 } 2567 2568 /* If we are taking the address of an external decl, it might be 2569 zero if it is weak, so we cannot optimize. */ 2570 if (DECL_P (inner) 2571 && DECL_EXTERNAL (inner)) 2572 break; 2573 2574 if (TREE_SIDE_EFFECTS (inner)) 2575 return build2 (COMPOUND_EXPR, truthvalue_type_node, 2576 inner, truthvalue_true_node); 2577 else 2578 return truthvalue_true_node; 2579 } 2580 2581 case COMPLEX_EXPR: 2582 return build_binary_op ((TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)) 2583 ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR), 2584 c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)), 2585 c_common_truthvalue_conversion (TREE_OPERAND (expr, 1)), 2586 0); 2587 2588 case NEGATE_EXPR: 2589 case ABS_EXPR: 2590 case FLOAT_EXPR: 2591 /* These don't change whether an object is nonzero or zero. */ 2592 return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)); 2593 2594 case LROTATE_EXPR: 2595 case RROTATE_EXPR: 2596 /* These don't change whether an object is zero or nonzero, but 2597 we can't ignore them if their second arg has side-effects. */ 2598 if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1))) 2599 return build2 (COMPOUND_EXPR, truthvalue_type_node, 2600 TREE_OPERAND (expr, 1), 2601 c_common_truthvalue_conversion (TREE_OPERAND (expr, 0))); 2602 else 2603 return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)); 2604 2605 case COND_EXPR: 2606 /* Distribute the conversion into the arms of a COND_EXPR. */ 2607 return fold_build3 (COND_EXPR, truthvalue_type_node, 2608 TREE_OPERAND (expr, 0), 2609 c_common_truthvalue_conversion (TREE_OPERAND (expr, 1)), 2610 c_common_truthvalue_conversion (TREE_OPERAND (expr, 2))); 2611 2612 case CONVERT_EXPR: 2613 case NOP_EXPR: 2614 /* Don't cancel the effect of a CONVERT_EXPR from a REFERENCE_TYPE, 2615 since that affects how `default_conversion' will behave. */ 2616 if (TREE_CODE (TREE_TYPE (expr)) == REFERENCE_TYPE 2617 || TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == REFERENCE_TYPE) 2618 break; 2619 /* If this is widening the argument, we can ignore it. */ 2620 if (TYPE_PRECISION (TREE_TYPE (expr)) 2621 >= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (expr, 0)))) 2622 return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)); 2623 break; 2624 2625 case MODIFY_EXPR: 2626 if (!TREE_NO_WARNING (expr) 2627 && warn_parentheses) 2628 { 2629 warning (OPT_Wparentheses, 2630 "suggest parentheses around assignment used as truth value"); 2631 TREE_NO_WARNING (expr) = 1; 2632 } 2633 break; 2634 2635 default: 2636 break; 2637 } 2638 2639 if (TREE_CODE (TREE_TYPE (expr)) == COMPLEX_TYPE) 2640 { 2641 tree t = save_expr (expr); 2642 return (build_binary_op 2643 ((TREE_SIDE_EFFECTS (expr) 2644 ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR), 2645 c_common_truthvalue_conversion (build_unary_op (REALPART_EXPR, t, 0)), 2646 c_common_truthvalue_conversion (build_unary_op (IMAGPART_EXPR, t, 0)), 2647 0)); 2648 } 2649 2650 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1); 2651} 2652 2653static void def_builtin_1 (enum built_in_function fncode, 2654 const char *name, 2655 enum built_in_class fnclass, 2656 tree fntype, tree libtype, 2657 bool both_p, bool fallback_p, bool nonansi_p, 2658 tree fnattrs, bool implicit_p); 2659 2660/* Make a variant type in the proper way for C/C++, propagating qualifiers 2661 down to the element type of an array. */ 2662 2663tree 2664c_build_qualified_type (tree type, int type_quals) 2665{ 2666 if (type == error_mark_node) 2667 return type; 2668 2669 if (TREE_CODE (type) == ARRAY_TYPE) 2670 { 2671 tree t; 2672 tree element_type = c_build_qualified_type (TREE_TYPE (type), 2673 type_quals); 2674 2675 /* See if we already have an identically qualified type. */ 2676 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t)) 2677 { 2678 if (TYPE_QUALS (strip_array_types (t)) == type_quals 2679 && TYPE_NAME (t) == TYPE_NAME (type) 2680 && TYPE_CONTEXT (t) == TYPE_CONTEXT (type) 2681 && attribute_list_equal (TYPE_ATTRIBUTES (t), 2682 TYPE_ATTRIBUTES (type))) 2683 break; 2684 } 2685 if (!t) 2686 { 2687 t = build_variant_type_copy (type); 2688 TREE_TYPE (t) = element_type; 2689 } 2690 return t; 2691 } 2692 2693 /* A restrict-qualified pointer type must be a pointer to object or 2694 incomplete type. Note that the use of POINTER_TYPE_P also allows 2695 REFERENCE_TYPEs, which is appropriate for C++. */ 2696 if ((type_quals & TYPE_QUAL_RESTRICT) 2697 && (!POINTER_TYPE_P (type) 2698 || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (type)))) 2699 { 2700 error ("invalid use of %<restrict%>"); 2701 type_quals &= ~TYPE_QUAL_RESTRICT; 2702 } 2703 2704 return build_qualified_type (type, type_quals); 2705} 2706 2707/* Apply the TYPE_QUALS to the new DECL. */ 2708 2709void 2710c_apply_type_quals_to_decl (int type_quals, tree decl) 2711{ 2712 tree type = TREE_TYPE (decl); 2713 2714 if (type == error_mark_node) 2715 return; 2716 2717 if (((type_quals & TYPE_QUAL_CONST) 2718 || (type && TREE_CODE (type) == REFERENCE_TYPE)) 2719 /* An object declared 'const' is only readonly after it is 2720 initialized. We don't have any way of expressing this currently, 2721 so we need to be conservative and unset TREE_READONLY for types 2722 with constructors. Otherwise aliasing code will ignore stores in 2723 an inline constructor. */ 2724 && !(type && TYPE_NEEDS_CONSTRUCTING (type))) 2725 TREE_READONLY (decl) = 1; 2726 if (type_quals & TYPE_QUAL_VOLATILE) 2727 { 2728 TREE_SIDE_EFFECTS (decl) = 1; 2729 TREE_THIS_VOLATILE (decl) = 1; 2730 } 2731 if (type_quals & TYPE_QUAL_RESTRICT) 2732 { 2733 while (type && TREE_CODE (type) == ARRAY_TYPE) 2734 /* Allow 'restrict' on arrays of pointers. 2735 FIXME currently we just ignore it. */ 2736 type = TREE_TYPE (type); 2737 if (!type 2738 || !POINTER_TYPE_P (type) 2739 || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (type))) 2740 error ("invalid use of %<restrict%>"); 2741 else if (flag_strict_aliasing && type == TREE_TYPE (decl)) 2742 /* Indicate we need to make a unique alias set for this pointer. 2743 We can't do it here because it might be pointing to an 2744 incomplete type. */ 2745 DECL_POINTER_ALIAS_SET (decl) = -2; 2746 } 2747} 2748 2749/* Hash function for the problem of multiple type definitions in 2750 different files. This must hash all types that will compare 2751 equal via comptypes to the same value. In practice it hashes 2752 on some of the simple stuff and leaves the details to comptypes. */ 2753 2754static hashval_t 2755c_type_hash (const void *p) 2756{ 2757 int i = 0; 2758 int shift, size; 2759 tree t = (tree) p; 2760 tree t2; 2761 switch (TREE_CODE (t)) 2762 { 2763 /* For pointers, hash on pointee type plus some swizzling. */ 2764 case POINTER_TYPE: 2765 return c_type_hash (TREE_TYPE (t)) ^ 0x3003003; 2766 /* Hash on number of elements and total size. */ 2767 case ENUMERAL_TYPE: 2768 shift = 3; 2769 t2 = TYPE_VALUES (t); 2770 break; 2771 case RECORD_TYPE: 2772 shift = 0; 2773 t2 = TYPE_FIELDS (t); 2774 break; 2775 case QUAL_UNION_TYPE: 2776 shift = 1; 2777 t2 = TYPE_FIELDS (t); 2778 break; 2779 case UNION_TYPE: 2780 shift = 2; 2781 t2 = TYPE_FIELDS (t); 2782 break; 2783 default: 2784 gcc_unreachable (); 2785 } 2786 for (; t2; t2 = TREE_CHAIN (t2)) 2787 i++; 2788 size = TREE_INT_CST_LOW (TYPE_SIZE (t)); 2789 return ((size << 24) | (i << shift)); 2790} 2791 2792static GTY((param_is (union tree_node))) htab_t type_hash_table; 2793 2794/* Return the typed-based alias set for T, which may be an expression 2795 or a type. Return -1 if we don't do anything special. */ 2796 2797HOST_WIDE_INT 2798c_common_get_alias_set (tree t) 2799{ 2800 tree u; 2801 PTR *slot; 2802 2803 /* Permit type-punning when accessing a union, provided the access 2804 is directly through the union. For example, this code does not 2805 permit taking the address of a union member and then storing 2806 through it. Even the type-punning allowed here is a GCC 2807 extension, albeit a common and useful one; the C standard says 2808 that such accesses have implementation-defined behavior. */ 2809 for (u = t; 2810 TREE_CODE (u) == COMPONENT_REF || TREE_CODE (u) == ARRAY_REF; 2811 u = TREE_OPERAND (u, 0)) 2812 if (TREE_CODE (u) == COMPONENT_REF 2813 && TREE_CODE (TREE_TYPE (TREE_OPERAND (u, 0))) == UNION_TYPE) 2814 return 0; 2815 2816 /* That's all the expressions we handle specially. */ 2817 if (!TYPE_P (t)) 2818 return -1; 2819 2820 /* The C standard guarantees that any object may be accessed via an 2821 lvalue that has character type. */ 2822 if (t == char_type_node 2823 || t == signed_char_type_node 2824 || t == unsigned_char_type_node) 2825 return 0; 2826 2827 /* If it has the may_alias attribute, it can alias anything. */ 2828 if (lookup_attribute ("may_alias", TYPE_ATTRIBUTES (t))) 2829 return 0; 2830 2831 /* The C standard specifically allows aliasing between signed and 2832 unsigned variants of the same type. We treat the signed 2833 variant as canonical. */ 2834 if (TREE_CODE (t) == INTEGER_TYPE && TYPE_UNSIGNED (t)) 2835 { 2836 tree t1 = c_common_signed_type (t); 2837 2838 /* t1 == t can happen for boolean nodes which are always unsigned. */ 2839 if (t1 != t) 2840 return get_alias_set (t1); 2841 } 2842 else if (POINTER_TYPE_P (t)) 2843 { 2844 tree t1; 2845 2846 /* Unfortunately, there is no canonical form of a pointer type. 2847 In particular, if we have `typedef int I', then `int *', and 2848 `I *' are different types. So, we have to pick a canonical 2849 representative. We do this below. 2850 2851 Technically, this approach is actually more conservative that 2852 it needs to be. In particular, `const int *' and `int *' 2853 should be in different alias sets, according to the C and C++ 2854 standard, since their types are not the same, and so, 2855 technically, an `int **' and `const int **' cannot point at 2856 the same thing. 2857 2858 But, the standard is wrong. In particular, this code is 2859 legal C++: 2860 2861 int *ip; 2862 int **ipp = &ip; 2863 const int* const* cipp = ipp; 2864 2865 And, it doesn't make sense for that to be legal unless you 2866 can dereference IPP and CIPP. So, we ignore cv-qualifiers on 2867 the pointed-to types. This issue has been reported to the 2868 C++ committee. */ 2869 t1 = build_type_no_quals (t); 2870 if (t1 != t) 2871 return get_alias_set (t1); 2872 } 2873 2874 /* Handle the case of multiple type nodes referring to "the same" type, 2875 which occurs with IMA. These share an alias set. FIXME: Currently only 2876 C90 is handled. (In C99 type compatibility is not transitive, which 2877 complicates things mightily. The alias set splay trees can theoretically 2878 represent this, but insertion is tricky when you consider all the 2879 different orders things might arrive in.) */ 2880 2881 if (c_language != clk_c || flag_isoc99) 2882 return -1; 2883 2884 /* Save time if there's only one input file. */ 2885 if (num_in_fnames == 1) 2886 return -1; 2887 2888 /* Pointers need special handling if they point to any type that 2889 needs special handling (below). */ 2890 if (TREE_CODE (t) == POINTER_TYPE) 2891 { 2892 tree t2; 2893 /* Find bottom type under any nested POINTERs. */ 2894 for (t2 = TREE_TYPE (t); 2895 TREE_CODE (t2) == POINTER_TYPE; 2896 t2 = TREE_TYPE (t2)) 2897 ; 2898 if (TREE_CODE (t2) != RECORD_TYPE 2899 && TREE_CODE (t2) != ENUMERAL_TYPE 2900 && TREE_CODE (t2) != QUAL_UNION_TYPE 2901 && TREE_CODE (t2) != UNION_TYPE) 2902 return -1; 2903 if (TYPE_SIZE (t2) == 0) 2904 return -1; 2905 } 2906 /* These are the only cases that need special handling. */ 2907 if (TREE_CODE (t) != RECORD_TYPE 2908 && TREE_CODE (t) != ENUMERAL_TYPE 2909 && TREE_CODE (t) != QUAL_UNION_TYPE 2910 && TREE_CODE (t) != UNION_TYPE 2911 && TREE_CODE (t) != POINTER_TYPE) 2912 return -1; 2913 /* Undefined? */ 2914 if (TYPE_SIZE (t) == 0) 2915 return -1; 2916 2917 /* Look up t in hash table. Only one of the compatible types within each 2918 alias set is recorded in the table. */ 2919 if (!type_hash_table) 2920 type_hash_table = htab_create_ggc (1021, c_type_hash, 2921 (htab_eq) lang_hooks.types_compatible_p, 2922 NULL); 2923 slot = htab_find_slot (type_hash_table, t, INSERT); 2924 if (*slot != NULL) 2925 { 2926 TYPE_ALIAS_SET (t) = TYPE_ALIAS_SET ((tree)*slot); 2927 return TYPE_ALIAS_SET ((tree)*slot); 2928 } 2929 else 2930 /* Our caller will assign and record (in t) a new alias set; all we need 2931 to do is remember t in the hash table. */ 2932 *slot = t; 2933 2934 return -1; 2935} 2936 2937/* Compute the value of 'sizeof (TYPE)' or '__alignof__ (TYPE)', where the 2938 second parameter indicates which OPERATOR is being applied. The COMPLAIN 2939 flag controls whether we should diagnose possibly ill-formed 2940 constructs or not. */ 2941 2942tree 2943c_sizeof_or_alignof_type (tree type, bool is_sizeof, int complain) 2944{ 2945 const char *op_name; 2946 tree value = NULL; 2947 enum tree_code type_code = TREE_CODE (type); 2948 2949 op_name = is_sizeof ? "sizeof" : "__alignof__"; 2950 2951 if (type_code == FUNCTION_TYPE) 2952 { 2953 if (is_sizeof) 2954 { 2955 if (complain && (pedantic || warn_pointer_arith)) 2956 pedwarn ("invalid application of %<sizeof%> to a function type"); 2957 value = size_one_node; 2958 } 2959 else 2960 value = size_int (FUNCTION_BOUNDARY / BITS_PER_UNIT); 2961 } 2962 else if (type_code == VOID_TYPE || type_code == ERROR_MARK) 2963 { 2964 if (type_code == VOID_TYPE 2965 && complain && (pedantic || warn_pointer_arith)) 2966 pedwarn ("invalid application of %qs to a void type", op_name); 2967 value = size_one_node; 2968 } 2969 else if (!COMPLETE_TYPE_P (type)) 2970 { 2971 if (complain) 2972 error ("invalid application of %qs to incomplete type %qT ", 2973 op_name, type); 2974 value = size_zero_node; 2975 } 2976 else 2977 { 2978 if (is_sizeof) 2979 /* Convert in case a char is more than one unit. */ 2980 value = size_binop (CEIL_DIV_EXPR, TYPE_SIZE_UNIT (type), 2981 size_int (TYPE_PRECISION (char_type_node) 2982 / BITS_PER_UNIT)); 2983 else 2984 value = size_int (TYPE_ALIGN_UNIT (type)); 2985 } 2986 2987 /* VALUE will have an integer type with TYPE_IS_SIZETYPE set. 2988 TYPE_IS_SIZETYPE means that certain things (like overflow) will 2989 never happen. However, this node should really have type 2990 `size_t', which is just a typedef for an ordinary integer type. */ 2991 value = fold_convert (size_type_node, value); 2992 gcc_assert (!TYPE_IS_SIZETYPE (TREE_TYPE (value))); 2993 2994 return value; 2995} 2996 2997/* Implement the __alignof keyword: Return the minimum required 2998 alignment of EXPR, measured in bytes. For VAR_DECLs, 2999 FUNCTION_DECLs and FIELD_DECLs return DECL_ALIGN (which can be set 3000 from an "aligned" __attribute__ specification). */ 3001 3002tree 3003c_alignof_expr (tree expr) 3004{ 3005 tree t; 3006 3007 if (VAR_OR_FUNCTION_DECL_P (expr)) 3008 t = size_int (DECL_ALIGN_UNIT (expr)); 3009 3010 else if (TREE_CODE (expr) == COMPONENT_REF 3011 && DECL_C_BIT_FIELD (TREE_OPERAND (expr, 1))) 3012 { 3013 error ("%<__alignof%> applied to a bit-field"); 3014 t = size_one_node; 3015 } 3016 else if (TREE_CODE (expr) == COMPONENT_REF 3017 && TREE_CODE (TREE_OPERAND (expr, 1)) == FIELD_DECL) 3018 t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (expr, 1))); 3019 3020 else if (TREE_CODE (expr) == INDIRECT_REF) 3021 { 3022 tree t = TREE_OPERAND (expr, 0); 3023 tree best = t; 3024 int bestalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t))); 3025 3026 while ((TREE_CODE (t) == NOP_EXPR || TREE_CODE (t) == CONVERT_EXPR) 3027 && TREE_CODE (TREE_TYPE (TREE_OPERAND (t, 0))) == POINTER_TYPE) 3028 { 3029 int thisalign; 3030 3031 t = TREE_OPERAND (t, 0); 3032 thisalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t))); 3033 if (thisalign > bestalign) 3034 best = t, bestalign = thisalign; 3035 } 3036 return c_alignof (TREE_TYPE (TREE_TYPE (best))); 3037 } 3038 else 3039 return c_alignof (TREE_TYPE (expr)); 3040 3041 return fold_convert (size_type_node, t); 3042} 3043 3044/* Handle C and C++ default attributes. */ 3045 3046enum built_in_attribute 3047{ 3048#define DEF_ATTR_NULL_TREE(ENUM) ENUM, 3049#define DEF_ATTR_INT(ENUM, VALUE) ENUM, 3050#define DEF_ATTR_IDENT(ENUM, STRING) ENUM, 3051#define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) ENUM, 3052#include "builtin-attrs.def" 3053#undef DEF_ATTR_NULL_TREE 3054#undef DEF_ATTR_INT 3055#undef DEF_ATTR_IDENT 3056#undef DEF_ATTR_TREE_LIST 3057 ATTR_LAST 3058}; 3059 3060static GTY(()) tree built_in_attributes[(int) ATTR_LAST]; 3061 3062static void c_init_attributes (void); 3063 3064enum c_builtin_type 3065{ 3066#define DEF_PRIMITIVE_TYPE(NAME, VALUE) NAME, 3067#define DEF_FUNCTION_TYPE_0(NAME, RETURN) NAME, 3068#define DEF_FUNCTION_TYPE_1(NAME, RETURN, ARG1) NAME, 3069#define DEF_FUNCTION_TYPE_2(NAME, RETURN, ARG1, ARG2) NAME, 3070#define DEF_FUNCTION_TYPE_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME, 3071#define DEF_FUNCTION_TYPE_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME, 3072#define DEF_FUNCTION_TYPE_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) NAME, 3073#define DEF_FUNCTION_TYPE_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6) NAME, 3074#define DEF_FUNCTION_TYPE_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7) NAME, 3075#define DEF_FUNCTION_TYPE_VAR_0(NAME, RETURN) NAME, 3076#define DEF_FUNCTION_TYPE_VAR_1(NAME, RETURN, ARG1) NAME, 3077#define DEF_FUNCTION_TYPE_VAR_2(NAME, RETURN, ARG1, ARG2) NAME, 3078#define DEF_FUNCTION_TYPE_VAR_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME, 3079#define DEF_FUNCTION_TYPE_VAR_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME, 3080#define DEF_FUNCTION_TYPE_VAR_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG6) \ 3081 NAME, 3082#define DEF_POINTER_TYPE(NAME, TYPE) NAME, 3083#include "builtin-types.def" 3084#undef DEF_PRIMITIVE_TYPE 3085#undef DEF_FUNCTION_TYPE_0 3086#undef DEF_FUNCTION_TYPE_1 3087#undef DEF_FUNCTION_TYPE_2 3088#undef DEF_FUNCTION_TYPE_3 3089#undef DEF_FUNCTION_TYPE_4 3090#undef DEF_FUNCTION_TYPE_5 3091#undef DEF_FUNCTION_TYPE_6 3092#undef DEF_FUNCTION_TYPE_7 3093#undef DEF_FUNCTION_TYPE_VAR_0 3094#undef DEF_FUNCTION_TYPE_VAR_1 3095#undef DEF_FUNCTION_TYPE_VAR_2 3096#undef DEF_FUNCTION_TYPE_VAR_3 3097#undef DEF_FUNCTION_TYPE_VAR_4 3098#undef DEF_FUNCTION_TYPE_VAR_5 3099#undef DEF_POINTER_TYPE 3100 BT_LAST 3101}; 3102 3103typedef enum c_builtin_type builtin_type; 3104 3105/* A temporary array for c_common_nodes_and_builtins. Used in 3106 communication with def_fn_type. */ 3107static tree builtin_types[(int) BT_LAST + 1]; 3108 3109/* A helper function for c_common_nodes_and_builtins. Build function type 3110 for DEF with return type RET and N arguments. If VAR is true, then the 3111 function should be variadic after those N arguments. 3112 3113 Takes special care not to ICE if any of the types involved are 3114 error_mark_node, which indicates that said type is not in fact available 3115 (see builtin_type_for_size). In which case the function type as a whole 3116 should be error_mark_node. */ 3117 3118static void 3119def_fn_type (builtin_type def, builtin_type ret, bool var, int n, ...) 3120{ 3121 tree args = NULL, t; 3122 va_list list; 3123 int i; 3124 3125 va_start (list, n); 3126 for (i = 0; i < n; ++i) 3127 { 3128 builtin_type a = va_arg (list, builtin_type); 3129 t = builtin_types[a]; 3130 if (t == error_mark_node) 3131 goto egress; 3132 args = tree_cons (NULL_TREE, t, args); 3133 } 3134 va_end (list); 3135 3136 args = nreverse (args); 3137 if (!var) 3138 args = chainon (args, void_list_node); 3139 3140 t = builtin_types[ret]; 3141 if (t == error_mark_node) 3142 goto egress; 3143 t = build_function_type (t, args); 3144 3145 egress: 3146 builtin_types[def] = t; 3147} 3148 3149/* Build builtin functions common to both C and C++ language 3150 frontends. */ 3151 3152static void 3153c_define_builtins (tree va_list_ref_type_node, tree va_list_arg_type_node) 3154{ 3155#define DEF_PRIMITIVE_TYPE(ENUM, VALUE) \ 3156 builtin_types[ENUM] = VALUE; 3157#define DEF_FUNCTION_TYPE_0(ENUM, RETURN) \ 3158 def_fn_type (ENUM, RETURN, 0, 0); 3159#define DEF_FUNCTION_TYPE_1(ENUM, RETURN, ARG1) \ 3160 def_fn_type (ENUM, RETURN, 0, 1, ARG1); 3161#define DEF_FUNCTION_TYPE_2(ENUM, RETURN, ARG1, ARG2) \ 3162 def_fn_type (ENUM, RETURN, 0, 2, ARG1, ARG2); 3163#define DEF_FUNCTION_TYPE_3(ENUM, RETURN, ARG1, ARG2, ARG3) \ 3164 def_fn_type (ENUM, RETURN, 0, 3, ARG1, ARG2, ARG3); 3165#define DEF_FUNCTION_TYPE_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \ 3166 def_fn_type (ENUM, RETURN, 0, 4, ARG1, ARG2, ARG3, ARG4); 3167#define DEF_FUNCTION_TYPE_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \ 3168 def_fn_type (ENUM, RETURN, 0, 5, ARG1, ARG2, ARG3, ARG4, ARG5); 3169#define DEF_FUNCTION_TYPE_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \ 3170 ARG6) \ 3171 def_fn_type (ENUM, RETURN, 0, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6); 3172#define DEF_FUNCTION_TYPE_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \ 3173 ARG6, ARG7) \ 3174 def_fn_type (ENUM, RETURN, 0, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7); 3175#define DEF_FUNCTION_TYPE_VAR_0(ENUM, RETURN) \ 3176 def_fn_type (ENUM, RETURN, 1, 0); 3177#define DEF_FUNCTION_TYPE_VAR_1(ENUM, RETURN, ARG1) \ 3178 def_fn_type (ENUM, RETURN, 1, 1, ARG1); 3179#define DEF_FUNCTION_TYPE_VAR_2(ENUM, RETURN, ARG1, ARG2) \ 3180 def_fn_type (ENUM, RETURN, 1, 2, ARG1, ARG2); 3181#define DEF_FUNCTION_TYPE_VAR_3(ENUM, RETURN, ARG1, ARG2, ARG3) \ 3182 def_fn_type (ENUM, RETURN, 1, 3, ARG1, ARG2, ARG3); 3183#define DEF_FUNCTION_TYPE_VAR_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \ 3184 def_fn_type (ENUM, RETURN, 1, 4, ARG1, ARG2, ARG3, ARG4); 3185#define DEF_FUNCTION_TYPE_VAR_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \ 3186 def_fn_type (ENUM, RETURN, 1, 5, ARG1, ARG2, ARG3, ARG4, ARG5); 3187#define DEF_POINTER_TYPE(ENUM, TYPE) \ 3188 builtin_types[(int) ENUM] = build_pointer_type (builtin_types[(int) TYPE]); 3189 3190#include "builtin-types.def" 3191 3192#undef DEF_PRIMITIVE_TYPE 3193#undef DEF_FUNCTION_TYPE_1 3194#undef DEF_FUNCTION_TYPE_2 3195#undef DEF_FUNCTION_TYPE_3 3196#undef DEF_FUNCTION_TYPE_4 3197#undef DEF_FUNCTION_TYPE_5 3198#undef DEF_FUNCTION_TYPE_6 3199#undef DEF_FUNCTION_TYPE_VAR_0 3200#undef DEF_FUNCTION_TYPE_VAR_1 3201#undef DEF_FUNCTION_TYPE_VAR_2 3202#undef DEF_FUNCTION_TYPE_VAR_3 3203#undef DEF_FUNCTION_TYPE_VAR_4 3204#undef DEF_FUNCTION_TYPE_VAR_5 3205#undef DEF_POINTER_TYPE 3206 builtin_types[(int) BT_LAST] = NULL_TREE; 3207 3208 c_init_attributes (); 3209 3210#define DEF_BUILTIN(ENUM, NAME, CLASS, TYPE, LIBTYPE, BOTH_P, FALLBACK_P, \ 3211 NONANSI_P, ATTRS, IMPLICIT, COND) \ 3212 if (NAME && COND) \ 3213 def_builtin_1 (ENUM, NAME, CLASS, \ 3214 builtin_types[(int) TYPE], \ 3215 builtin_types[(int) LIBTYPE], \ 3216 BOTH_P, FALLBACK_P, NONANSI_P, \ 3217 built_in_attributes[(int) ATTRS], IMPLICIT); 3218#include "builtins.def" 3219#undef DEF_BUILTIN 3220 3221 build_common_builtin_nodes (); 3222 3223 targetm.init_builtins (); 3224 if (flag_mudflap) 3225 mudflap_init (); 3226} 3227 3228/* Build tree nodes and builtin functions common to both C and C++ language 3229 frontends. */ 3230 3231void 3232c_common_nodes_and_builtins (void) 3233{ 3234 int wchar_type_size; 3235 tree array_domain_type; 3236 tree va_list_ref_type_node; 3237 tree va_list_arg_type_node; 3238 3239 /* Define `int' and `char' first so that dbx will output them first. */ 3240 record_builtin_type (RID_INT, NULL, integer_type_node); 3241 record_builtin_type (RID_CHAR, "char", char_type_node); 3242 3243 /* `signed' is the same as `int'. FIXME: the declarations of "signed", 3244 "unsigned long", "long long unsigned" and "unsigned short" were in C++ 3245 but not C. Are the conditionals here needed? */ 3246 if (c_dialect_cxx ()) 3247 record_builtin_type (RID_SIGNED, NULL, integer_type_node); 3248 record_builtin_type (RID_LONG, "long int", long_integer_type_node); 3249 record_builtin_type (RID_UNSIGNED, "unsigned int", unsigned_type_node); 3250 record_builtin_type (RID_MAX, "long unsigned int", 3251 long_unsigned_type_node); 3252 if (c_dialect_cxx ()) 3253 record_builtin_type (RID_MAX, "unsigned long", long_unsigned_type_node); 3254 record_builtin_type (RID_MAX, "long long int", 3255 long_long_integer_type_node); 3256 record_builtin_type (RID_MAX, "long long unsigned int", 3257 long_long_unsigned_type_node); 3258 if (c_dialect_cxx ()) 3259 record_builtin_type (RID_MAX, "long long unsigned", 3260 long_long_unsigned_type_node); 3261 record_builtin_type (RID_SHORT, "short int", short_integer_type_node); 3262 record_builtin_type (RID_MAX, "short unsigned int", 3263 short_unsigned_type_node); 3264 if (c_dialect_cxx ()) 3265 record_builtin_type (RID_MAX, "unsigned short", 3266 short_unsigned_type_node); 3267 3268 /* Define both `signed char' and `unsigned char'. */ 3269 record_builtin_type (RID_MAX, "signed char", signed_char_type_node); 3270 record_builtin_type (RID_MAX, "unsigned char", unsigned_char_type_node); 3271 3272 /* These are types that c_common_type_for_size and 3273 c_common_type_for_mode use. */ 3274 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE, 3275 intQI_type_node)); 3276 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE, 3277 intHI_type_node)); 3278 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE, 3279 intSI_type_node)); 3280 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE, 3281 intDI_type_node)); 3282#if HOST_BITS_PER_WIDE_INT >= 64 3283 if (targetm.scalar_mode_supported_p (TImode)) 3284 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, 3285 get_identifier ("__int128_t"), 3286 intTI_type_node)); 3287#endif 3288 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE, 3289 unsigned_intQI_type_node)); 3290 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE, 3291 unsigned_intHI_type_node)); 3292 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE, 3293 unsigned_intSI_type_node)); 3294 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE, 3295 unsigned_intDI_type_node)); 3296#if HOST_BITS_PER_WIDE_INT >= 64 3297 if (targetm.scalar_mode_supported_p (TImode)) 3298 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, 3299 get_identifier ("__uint128_t"), 3300 unsigned_intTI_type_node)); 3301#endif 3302 3303 /* Create the widest literal types. */ 3304 widest_integer_literal_type_node 3305 = make_signed_type (HOST_BITS_PER_WIDE_INT * 2); 3306 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE, 3307 widest_integer_literal_type_node)); 3308 3309 widest_unsigned_literal_type_node 3310 = make_unsigned_type (HOST_BITS_PER_WIDE_INT * 2); 3311 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE, 3312 widest_unsigned_literal_type_node)); 3313 3314 /* `unsigned long' is the standard type for sizeof. 3315 Note that stddef.h uses `unsigned long', 3316 and this must agree, even if long and int are the same size. */ 3317 size_type_node = 3318 TREE_TYPE (identifier_global_value (get_identifier (SIZE_TYPE))); 3319 signed_size_type_node = c_common_signed_type (size_type_node); 3320 set_sizetype (size_type_node); 3321 3322 pid_type_node = 3323 TREE_TYPE (identifier_global_value (get_identifier (PID_TYPE))); 3324 3325 build_common_tree_nodes_2 (flag_short_double); 3326 3327 record_builtin_type (RID_FLOAT, NULL, float_type_node); 3328 record_builtin_type (RID_DOUBLE, NULL, double_type_node); 3329 record_builtin_type (RID_MAX, "long double", long_double_type_node); 3330 3331 /* Only supported decimal floating point extension if the target 3332 actually supports underlying modes. */ 3333 if (targetm.scalar_mode_supported_p (SDmode) 3334 && targetm.scalar_mode_supported_p (DDmode) 3335 && targetm.scalar_mode_supported_p (TDmode)) 3336 { 3337 record_builtin_type (RID_DFLOAT32, NULL, dfloat32_type_node); 3338 record_builtin_type (RID_DFLOAT64, NULL, dfloat64_type_node); 3339 record_builtin_type (RID_DFLOAT128, NULL, dfloat128_type_node); 3340 } 3341 3342 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, 3343 get_identifier ("complex int"), 3344 complex_integer_type_node)); 3345 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, 3346 get_identifier ("complex float"), 3347 complex_float_type_node)); 3348 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, 3349 get_identifier ("complex double"), 3350 complex_double_type_node)); 3351 lang_hooks.decls.pushdecl 3352 (build_decl (TYPE_DECL, get_identifier ("complex long double"), 3353 complex_long_double_type_node)); 3354 3355 if (c_dialect_cxx ()) 3356 /* For C++, make fileptr_type_node a distinct void * type until 3357 FILE type is defined. */ 3358 fileptr_type_node = build_variant_type_copy (ptr_type_node); 3359 3360 record_builtin_type (RID_VOID, NULL, void_type_node); 3361 3362 /* This node must not be shared. */ 3363 void_zero_node = make_node (INTEGER_CST); 3364 TREE_TYPE (void_zero_node) = void_type_node; 3365 3366 void_list_node = build_void_list_node (); 3367 3368 /* Make a type to be the domain of a few array types 3369 whose domains don't really matter. 3370 200 is small enough that it always fits in size_t 3371 and large enough that it can hold most function names for the 3372 initializations of __FUNCTION__ and __PRETTY_FUNCTION__. */ 3373 array_domain_type = build_index_type (size_int (200)); 3374 3375 /* Make a type for arrays of characters. 3376 With luck nothing will ever really depend on the length of this 3377 array type. */ 3378 char_array_type_node 3379 = build_array_type (char_type_node, array_domain_type); 3380 3381 /* Likewise for arrays of ints. */ 3382 int_array_type_node 3383 = build_array_type (integer_type_node, array_domain_type); 3384 3385 string_type_node = build_pointer_type (char_type_node); 3386 const_string_type_node 3387 = build_pointer_type (build_qualified_type 3388 (char_type_node, TYPE_QUAL_CONST)); 3389 3390 /* This is special for C++ so functions can be overloaded. */ 3391 wchar_type_node = get_identifier (MODIFIED_WCHAR_TYPE); 3392 wchar_type_node = TREE_TYPE (identifier_global_value (wchar_type_node)); 3393 wchar_type_size = TYPE_PRECISION (wchar_type_node); 3394 if (c_dialect_cxx ()) 3395 { 3396 if (TYPE_UNSIGNED (wchar_type_node)) 3397 wchar_type_node = make_unsigned_type (wchar_type_size); 3398 else 3399 wchar_type_node = make_signed_type (wchar_type_size); 3400 record_builtin_type (RID_WCHAR, "wchar_t", wchar_type_node); 3401 } 3402 else 3403 { 3404 signed_wchar_type_node = c_common_signed_type (wchar_type_node); 3405 unsigned_wchar_type_node = c_common_unsigned_type (wchar_type_node); 3406 } 3407 3408 /* This is for wide string constants. */ 3409 wchar_array_type_node 3410 = build_array_type (wchar_type_node, array_domain_type); 3411 3412 wint_type_node = 3413 TREE_TYPE (identifier_global_value (get_identifier (WINT_TYPE))); 3414 3415 intmax_type_node = 3416 TREE_TYPE (identifier_global_value (get_identifier (INTMAX_TYPE))); 3417 uintmax_type_node = 3418 TREE_TYPE (identifier_global_value (get_identifier (UINTMAX_TYPE))); 3419 3420 default_function_type = build_function_type (integer_type_node, NULL_TREE); 3421 ptrdiff_type_node 3422 = TREE_TYPE (identifier_global_value (get_identifier (PTRDIFF_TYPE))); 3423 unsigned_ptrdiff_type_node = c_common_unsigned_type (ptrdiff_type_node); 3424 3425 lang_hooks.decls.pushdecl 3426 (build_decl (TYPE_DECL, get_identifier ("__builtin_va_list"), 3427 va_list_type_node)); 3428 3429 if (TREE_CODE (va_list_type_node) == ARRAY_TYPE) 3430 { 3431 va_list_arg_type_node = va_list_ref_type_node = 3432 build_pointer_type (TREE_TYPE (va_list_type_node)); 3433 } 3434 else 3435 { 3436 va_list_arg_type_node = va_list_type_node; 3437 va_list_ref_type_node = build_reference_type (va_list_type_node); 3438 } 3439 3440 if (!flag_preprocess_only) 3441 c_define_builtins (va_list_ref_type_node, va_list_arg_type_node); 3442 3443 main_identifier_node = get_identifier ("main"); 3444 3445 /* Create the built-in __null node. It is important that this is 3446 not shared. */ 3447 null_node = make_node (INTEGER_CST); 3448 TREE_TYPE (null_node) = c_common_type_for_size (POINTER_SIZE, 0); 3449 3450 /* Since builtin_types isn't gc'ed, don't export these nodes. */ 3451 memset (builtin_types, 0, sizeof (builtin_types)); 3452} 3453 3454/* Look up the function in built_in_decls that corresponds to DECL 3455 and set ASMSPEC as its user assembler name. DECL must be a 3456 function decl that declares a builtin. */ 3457 3458void 3459set_builtin_user_assembler_name (tree decl, const char *asmspec) 3460{ 3461 tree builtin; 3462 gcc_assert (TREE_CODE (decl) == FUNCTION_DECL 3463 && DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL 3464 && asmspec != 0); 3465 3466 builtin = built_in_decls [DECL_FUNCTION_CODE (decl)]; 3467 set_user_assembler_name (builtin, asmspec); 3468 if (DECL_FUNCTION_CODE (decl) == BUILT_IN_MEMCPY) 3469 init_block_move_fn (asmspec); 3470 else if (DECL_FUNCTION_CODE (decl) == BUILT_IN_MEMSET) 3471 init_block_clear_fn (asmspec); 3472} 3473 3474/* The number of named compound-literals generated thus far. */ 3475static GTY(()) int compound_literal_number; 3476 3477/* Set DECL_NAME for DECL, a VAR_DECL for a compound-literal. */ 3478 3479void 3480set_compound_literal_name (tree decl) 3481{ 3482 char *name; 3483 ASM_FORMAT_PRIVATE_NAME (name, "__compound_literal", 3484 compound_literal_number); 3485 compound_literal_number++; 3486 DECL_NAME (decl) = get_identifier (name); 3487} 3488 3489tree 3490build_va_arg (tree expr, tree type) 3491{ 3492 return build1 (VA_ARG_EXPR, type, expr); 3493} 3494 3495 3496/* Linked list of disabled built-in functions. */ 3497 3498typedef struct disabled_builtin 3499{ 3500 const char *name; 3501 struct disabled_builtin *next; 3502} disabled_builtin; 3503static disabled_builtin *disabled_builtins = NULL; 3504 3505static bool builtin_function_disabled_p (const char *); 3506 3507/* Disable a built-in function specified by -fno-builtin-NAME. If NAME 3508 begins with "__builtin_", give an error. */ 3509 3510void 3511disable_builtin_function (const char *name) 3512{ 3513 if (strncmp (name, "__builtin_", strlen ("__builtin_")) == 0) 3514 error ("cannot disable built-in function %qs", name); 3515 else 3516 { 3517 disabled_builtin *new_disabled_builtin = XNEW (disabled_builtin); 3518 new_disabled_builtin->name = name; 3519 new_disabled_builtin->next = disabled_builtins; 3520 disabled_builtins = new_disabled_builtin; 3521 } 3522} 3523 3524 3525/* Return true if the built-in function NAME has been disabled, false 3526 otherwise. */ 3527 3528static bool 3529builtin_function_disabled_p (const char *name) 3530{ 3531 disabled_builtin *p; 3532 for (p = disabled_builtins; p != NULL; p = p->next) 3533 { 3534 if (strcmp (name, p->name) == 0) 3535 return true; 3536 } 3537 return false; 3538} 3539 3540 3541/* Worker for DEF_BUILTIN. 3542 Possibly define a builtin function with one or two names. 3543 Does not declare a non-__builtin_ function if flag_no_builtin, or if 3544 nonansi_p and flag_no_nonansi_builtin. */ 3545 3546static void 3547def_builtin_1 (enum built_in_function fncode, 3548 const char *name, 3549 enum built_in_class fnclass, 3550 tree fntype, tree libtype, 3551 bool both_p, bool fallback_p, bool nonansi_p, 3552 tree fnattrs, bool implicit_p) 3553{ 3554 tree decl; 3555 const char *libname; 3556 3557 if (fntype == error_mark_node) 3558 return; 3559 3560 gcc_assert ((!both_p && !fallback_p) 3561 || !strncmp (name, "__builtin_", 3562 strlen ("__builtin_"))); 3563 3564 libname = name + strlen ("__builtin_"); 3565 decl = lang_hooks.builtin_function (name, fntype, fncode, fnclass, 3566 (fallback_p ? libname : NULL), 3567 fnattrs); 3568 if (both_p 3569 && !flag_no_builtin && !builtin_function_disabled_p (libname) 3570 && !(nonansi_p && flag_no_nonansi_builtin)) 3571 lang_hooks.builtin_function (libname, libtype, fncode, fnclass, 3572 NULL, fnattrs); 3573 3574 built_in_decls[(int) fncode] = decl; 3575 if (implicit_p) 3576 implicit_built_in_decls[(int) fncode] = decl; 3577} 3578 3579/* Nonzero if the type T promotes to int. This is (nearly) the 3580 integral promotions defined in ISO C99 6.3.1.1/2. */ 3581 3582bool 3583c_promoting_integer_type_p (tree t) 3584{ 3585 switch (TREE_CODE (t)) 3586 { 3587 case INTEGER_TYPE: 3588 return (TYPE_MAIN_VARIANT (t) == char_type_node 3589 || TYPE_MAIN_VARIANT (t) == signed_char_type_node 3590 || TYPE_MAIN_VARIANT (t) == unsigned_char_type_node 3591 || TYPE_MAIN_VARIANT (t) == short_integer_type_node 3592 || TYPE_MAIN_VARIANT (t) == short_unsigned_type_node 3593 || TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node)); 3594 3595 case ENUMERAL_TYPE: 3596 /* ??? Technically all enumerations not larger than an int 3597 promote to an int. But this is used along code paths 3598 that only want to notice a size change. */ 3599 return TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node); 3600 3601 case BOOLEAN_TYPE: 3602 return 1; 3603 3604 default: 3605 return 0; 3606 } 3607} 3608 3609/* Return 1 if PARMS specifies a fixed number of parameters 3610 and none of their types is affected by default promotions. */ 3611 3612int 3613self_promoting_args_p (tree parms) 3614{ 3615 tree t; 3616 for (t = parms; t; t = TREE_CHAIN (t)) 3617 { 3618 tree type = TREE_VALUE (t); 3619 3620 if (type == error_mark_node) 3621 continue; 3622 3623 if (TREE_CHAIN (t) == 0 && type != void_type_node) 3624 return 0; 3625 3626 if (type == 0) 3627 return 0; 3628 3629 if (TYPE_MAIN_VARIANT (type) == float_type_node) 3630 return 0; 3631 3632 if (c_promoting_integer_type_p (type)) 3633 return 0; 3634 } 3635 return 1; 3636} 3637 3638/* Recursively examines the array elements of TYPE, until a non-array 3639 element type is found. */ 3640 3641tree 3642strip_array_types (tree type) 3643{ 3644 while (TREE_CODE (type) == ARRAY_TYPE) 3645 type = TREE_TYPE (type); 3646 3647 return type; 3648} 3649 3650/* Recursively remove any '*' or '&' operator from TYPE. */ 3651tree 3652strip_pointer_operator (tree t) 3653{ 3654 while (POINTER_TYPE_P (t)) 3655 t = TREE_TYPE (t); 3656 return t; 3657} 3658 3659/* Used to compare case labels. K1 and K2 are actually tree nodes 3660 representing case labels, or NULL_TREE for a `default' label. 3661 Returns -1 if K1 is ordered before K2, -1 if K1 is ordered after 3662 K2, and 0 if K1 and K2 are equal. */ 3663 3664int 3665case_compare (splay_tree_key k1, splay_tree_key k2) 3666{ 3667 /* Consider a NULL key (such as arises with a `default' label) to be 3668 smaller than anything else. */ 3669 if (!k1) 3670 return k2 ? -1 : 0; 3671 else if (!k2) 3672 return k1 ? 1 : 0; 3673 3674 return tree_int_cst_compare ((tree) k1, (tree) k2); 3675} 3676 3677/* Process a case label for the range LOW_VALUE ... HIGH_VALUE. If 3678 LOW_VALUE and HIGH_VALUE are both NULL_TREE then this case label is 3679 actually a `default' label. If only HIGH_VALUE is NULL_TREE, then 3680 case label was declared using the usual C/C++ syntax, rather than 3681 the GNU case range extension. CASES is a tree containing all the 3682 case ranges processed so far; COND is the condition for the 3683 switch-statement itself. Returns the CASE_LABEL_EXPR created, or 3684 ERROR_MARK_NODE if no CASE_LABEL_EXPR is created. */ 3685 3686tree 3687c_add_case_label (splay_tree cases, tree cond, tree orig_type, 3688 tree low_value, tree high_value) 3689{ 3690 tree type; 3691 tree label; 3692 tree case_label; 3693 splay_tree_node node; 3694 3695 /* Create the LABEL_DECL itself. */ 3696 label = create_artificial_label (); 3697 3698 /* If there was an error processing the switch condition, bail now 3699 before we get more confused. */ 3700 if (!cond || cond == error_mark_node) 3701 goto error_out; 3702 3703 if ((low_value && TREE_TYPE (low_value) 3704 && POINTER_TYPE_P (TREE_TYPE (low_value))) 3705 || (high_value && TREE_TYPE (high_value) 3706 && POINTER_TYPE_P (TREE_TYPE (high_value)))) 3707 { 3708 error ("pointers are not permitted as case values"); 3709 goto error_out; 3710 } 3711 3712 /* Case ranges are a GNU extension. */ 3713 if (high_value && pedantic) 3714 pedwarn ("range expressions in switch statements are non-standard"); 3715 3716 type = TREE_TYPE (cond); 3717 if (low_value) 3718 { 3719 low_value = check_case_value (low_value); 3720 low_value = convert_and_check (type, low_value); 3721 if (low_value == error_mark_node) 3722 goto error_out; 3723 } 3724 if (high_value) 3725 { 3726 high_value = check_case_value (high_value); 3727 high_value = convert_and_check (type, high_value); 3728 if (high_value == error_mark_node) 3729 goto error_out; 3730 } 3731 3732 if (low_value && high_value) 3733 { 3734 /* If the LOW_VALUE and HIGH_VALUE are the same, then this isn't 3735 really a case range, even though it was written that way. 3736 Remove the HIGH_VALUE to simplify later processing. */ 3737 if (tree_int_cst_equal (low_value, high_value)) 3738 high_value = NULL_TREE; 3739 else if (!tree_int_cst_lt (low_value, high_value)) 3740 warning (0, "empty range specified"); 3741 } 3742 3743 /* See if the case is in range of the type of the original testing 3744 expression. If both low_value and high_value are out of range, 3745 don't insert the case label and return NULL_TREE. */ 3746 if (low_value 3747 && !check_case_bounds (type, orig_type, 3748 &low_value, high_value ? &high_value : NULL)) 3749 return NULL_TREE; 3750 3751 /* Look up the LOW_VALUE in the table of case labels we already 3752 have. */ 3753 node = splay_tree_lookup (cases, (splay_tree_key) low_value); 3754 /* If there was not an exact match, check for overlapping ranges. 3755 There's no need to do this if there's no LOW_VALUE or HIGH_VALUE; 3756 that's a `default' label and the only overlap is an exact match. */ 3757 if (!node && (low_value || high_value)) 3758 { 3759 splay_tree_node low_bound; 3760 splay_tree_node high_bound; 3761 3762 /* Even though there wasn't an exact match, there might be an 3763 overlap between this case range and another case range. 3764 Since we've (inductively) not allowed any overlapping case 3765 ranges, we simply need to find the greatest low case label 3766 that is smaller that LOW_VALUE, and the smallest low case 3767 label that is greater than LOW_VALUE. If there is an overlap 3768 it will occur in one of these two ranges. */ 3769 low_bound = splay_tree_predecessor (cases, 3770 (splay_tree_key) low_value); 3771 high_bound = splay_tree_successor (cases, 3772 (splay_tree_key) low_value); 3773 3774 /* Check to see if the LOW_BOUND overlaps. It is smaller than 3775 the LOW_VALUE, so there is no need to check unless the 3776 LOW_BOUND is in fact itself a case range. */ 3777 if (low_bound 3778 && CASE_HIGH ((tree) low_bound->value) 3779 && tree_int_cst_compare (CASE_HIGH ((tree) low_bound->value), 3780 low_value) >= 0) 3781 node = low_bound; 3782 /* Check to see if the HIGH_BOUND overlaps. The low end of that 3783 range is bigger than the low end of the current range, so we 3784 are only interested if the current range is a real range, and 3785 not an ordinary case label. */ 3786 else if (high_bound 3787 && high_value 3788 && (tree_int_cst_compare ((tree) high_bound->key, 3789 high_value) 3790 <= 0)) 3791 node = high_bound; 3792 } 3793 /* If there was an overlap, issue an error. */ 3794 if (node) 3795 { 3796 tree duplicate = CASE_LABEL ((tree) node->value); 3797 3798 if (high_value) 3799 { 3800 error ("duplicate (or overlapping) case value"); 3801 error ("%Jthis is the first entry overlapping that value", duplicate); 3802 } 3803 else if (low_value) 3804 { 3805 error ("duplicate case value") ; 3806 error ("%Jpreviously used here", duplicate); 3807 } 3808 else 3809 { 3810 error ("multiple default labels in one switch"); 3811 error ("%Jthis is the first default label", duplicate); 3812 } 3813 goto error_out; 3814 } 3815 3816 /* Add a CASE_LABEL to the statement-tree. */ 3817 case_label = add_stmt (build_case_label (low_value, high_value, label)); 3818 /* Register this case label in the splay tree. */ 3819 splay_tree_insert (cases, 3820 (splay_tree_key) low_value, 3821 (splay_tree_value) case_label); 3822 3823 return case_label; 3824 3825 error_out: 3826 /* Add a label so that the back-end doesn't think that the beginning of 3827 the switch is unreachable. Note that we do not add a case label, as 3828 that just leads to duplicates and thence to failure later on. */ 3829 if (!cases->root) 3830 { 3831 tree t = create_artificial_label (); 3832 add_stmt (build_stmt (LABEL_EXPR, t)); 3833 } 3834 return error_mark_node; 3835} 3836 3837/* Subroutines of c_do_switch_warnings, called via splay_tree_foreach. 3838 Used to verify that case values match up with enumerator values. */ 3839 3840static void 3841match_case_to_enum_1 (tree key, tree type, tree label) 3842{ 3843 char buf[2 + 2*HOST_BITS_PER_WIDE_INT/4 + 1]; 3844 3845 /* ??? Not working too hard to print the double-word value. 3846 Should perhaps be done with %lwd in the diagnostic routines? */ 3847 if (TREE_INT_CST_HIGH (key) == 0) 3848 snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_UNSIGNED, 3849 TREE_INT_CST_LOW (key)); 3850 else if (!TYPE_UNSIGNED (type) 3851 && TREE_INT_CST_HIGH (key) == -1 3852 && TREE_INT_CST_LOW (key) != 0) 3853 snprintf (buf, sizeof (buf), "-" HOST_WIDE_INT_PRINT_UNSIGNED, 3854 -TREE_INT_CST_LOW (key)); 3855 else 3856 snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_DOUBLE_HEX, 3857 TREE_INT_CST_HIGH (key), TREE_INT_CST_LOW (key)); 3858 3859 if (TYPE_NAME (type) == 0) 3860 warning (0, "%Jcase value %qs not in enumerated type", 3861 CASE_LABEL (label), buf); 3862 else 3863 warning (0, "%Jcase value %qs not in enumerated type %qT", 3864 CASE_LABEL (label), buf, type); 3865} 3866 3867/* Subroutine of c_do_switch_warnings, called via splay_tree_foreach. 3868 Used to verify that case values match up with enumerator values. */ 3869 3870static int 3871match_case_to_enum (splay_tree_node node, void *data) 3872{ 3873 tree label = (tree) node->value; 3874 tree type = (tree) data; 3875 3876 /* Skip default case. */ 3877 if (!CASE_LOW (label)) 3878 return 0; 3879 3880 /* If CASE_LOW_SEEN is not set, that means CASE_LOW did not appear 3881 when we did our enum->case scan. Reset our scratch bit after. */ 3882 if (!CASE_LOW_SEEN (label)) 3883 match_case_to_enum_1 (CASE_LOW (label), type, label); 3884 else 3885 CASE_LOW_SEEN (label) = 0; 3886 3887 /* If CASE_HIGH is non-null, we have a range. If CASE_HIGH_SEEN is 3888 not set, that means that CASE_HIGH did not appear when we did our 3889 enum->case scan. Reset our scratch bit after. */ 3890 if (CASE_HIGH (label)) 3891 { 3892 if (!CASE_HIGH_SEEN (label)) 3893 match_case_to_enum_1 (CASE_HIGH (label), type, label); 3894 else 3895 CASE_HIGH_SEEN (label) = 0; 3896 } 3897 3898 return 0; 3899} 3900 3901/* Handle -Wswitch*. Called from the front end after parsing the 3902 switch construct. */ 3903/* ??? Should probably be somewhere generic, since other languages 3904 besides C and C++ would want this. At the moment, however, C/C++ 3905 are the only tree-ssa languages that support enumerations at all, 3906 so the point is moot. */ 3907 3908void 3909c_do_switch_warnings (splay_tree cases, location_t switch_location, 3910 tree type, tree cond) 3911{ 3912 splay_tree_node default_node; 3913 splay_tree_node node; 3914 tree chain; 3915 3916 if (!warn_switch && !warn_switch_enum && !warn_switch_default) 3917 return; 3918 3919 default_node = splay_tree_lookup (cases, (splay_tree_key) NULL); 3920 if (!default_node) 3921 warning (OPT_Wswitch_default, "%Hswitch missing default case", 3922 &switch_location); 3923 3924 /* From here on, we only care about about enumerated types. */ 3925 if (!type || TREE_CODE (type) != ENUMERAL_TYPE) 3926 return; 3927 3928 /* If the switch expression was an enumerated type, check that 3929 exactly all enumeration literals are covered by the cases. 3930 The check is made when -Wswitch was specified and there is no 3931 default case, or when -Wswitch-enum was specified. */ 3932 3933 if (!warn_switch_enum 3934 && !(warn_switch && !default_node)) 3935 return; 3936 3937 /* Clearing COND if it is not an integer constant simplifies 3938 the tests inside the loop below. */ 3939 if (TREE_CODE (cond) != INTEGER_CST) 3940 cond = NULL_TREE; 3941 3942 /* The time complexity here is O(N*lg(N)) worst case, but for the 3943 common case of monotonically increasing enumerators, it is 3944 O(N), since the nature of the splay tree will keep the next 3945 element adjacent to the root at all times. */ 3946 3947 for (chain = TYPE_VALUES (type); chain; chain = TREE_CHAIN (chain)) 3948 { 3949 tree value = TREE_VALUE (chain); 3950 node = splay_tree_lookup (cases, (splay_tree_key) value); 3951 if (node) 3952 { 3953 /* Mark the CASE_LOW part of the case entry as seen. */ 3954 tree label = (tree) node->value; 3955 CASE_LOW_SEEN (label) = 1; 3956 continue; 3957 } 3958 3959 /* Even though there wasn't an exact match, there might be a 3960 case range which includes the enumator's value. */ 3961 node = splay_tree_predecessor (cases, (splay_tree_key) value); 3962 if (node && CASE_HIGH ((tree) node->value)) 3963 { 3964 tree label = (tree) node->value; 3965 int cmp = tree_int_cst_compare (CASE_HIGH (label), value); 3966 if (cmp >= 0) 3967 { 3968 /* If we match the upper bound exactly, mark the CASE_HIGH 3969 part of the case entry as seen. */ 3970 if (cmp == 0) 3971 CASE_HIGH_SEEN (label) = 1; 3972 continue; 3973 } 3974 } 3975 3976 /* We've now determined that this enumerated literal isn't 3977 handled by the case labels of the switch statement. */ 3978 3979 /* If the switch expression is a constant, we only really care 3980 about whether that constant is handled by the switch. */ 3981 if (cond && tree_int_cst_compare (cond, value)) 3982 continue; 3983 3984 warning (0, "%Henumeration value %qE not handled in switch", 3985 &switch_location, TREE_PURPOSE (chain)); 3986 } 3987 3988 /* Warn if there are case expressions that don't correspond to 3989 enumerators. This can occur since C and C++ don't enforce 3990 type-checking of assignments to enumeration variables. 3991 3992 The time complexity here is now always O(N) worst case, since 3993 we should have marked both the lower bound and upper bound of 3994 every disjoint case label, with CASE_LOW_SEEN and CASE_HIGH_SEEN 3995 above. This scan also resets those fields. */ 3996 splay_tree_foreach (cases, match_case_to_enum, type); 3997} 3998 3999/* Finish an expression taking the address of LABEL (an 4000 IDENTIFIER_NODE). Returns an expression for the address. */ 4001 4002tree 4003finish_label_address_expr (tree label) 4004{ 4005 tree result; 4006 4007 if (pedantic) 4008 pedwarn ("taking the address of a label is non-standard"); 4009 4010 if (label == error_mark_node) 4011 return error_mark_node; 4012 4013 label = lookup_label (label); 4014 if (label == NULL_TREE) 4015 result = null_pointer_node; 4016 else 4017 { 4018 TREE_USED (label) = 1; 4019 result = build1 (ADDR_EXPR, ptr_type_node, label); 4020 /* The current function in not necessarily uninlinable. 4021 Computed gotos are incompatible with inlining, but the value 4022 here could be used only in a diagnostic, for example. */ 4023 } 4024 4025 return result; 4026} 4027 4028/* Hook used by expand_expr to expand language-specific tree codes. */ 4029/* The only things that should go here are bits needed to expand 4030 constant initializers. Everything else should be handled by the 4031 gimplification routines. */ 4032 4033rtx 4034c_expand_expr (tree exp, rtx target, enum machine_mode tmode, 4035 int modifier /* Actually enum_modifier. */, 4036 rtx *alt_rtl) 4037{ 4038 switch (TREE_CODE (exp)) 4039 { 4040 case COMPOUND_LITERAL_EXPR: 4041 { 4042 /* Initialize the anonymous variable declared in the compound 4043 literal, then return the variable. */ 4044 tree decl = COMPOUND_LITERAL_EXPR_DECL (exp); 4045 emit_local_var (decl); 4046 return expand_expr_real (decl, target, tmode, modifier, alt_rtl); 4047 } 4048 4049 default: 4050 gcc_unreachable (); 4051 } 4052} 4053 4054/* Hook used by staticp to handle language-specific tree codes. */ 4055 4056tree 4057c_staticp (tree exp) 4058{ 4059 return (TREE_CODE (exp) == COMPOUND_LITERAL_EXPR 4060 && TREE_STATIC (COMPOUND_LITERAL_EXPR_DECL (exp)) 4061 ? exp : NULL); 4062} 4063 4064 4065/* Given a boolean expression ARG, return a tree representing an increment 4066 or decrement (as indicated by CODE) of ARG. The front end must check for 4067 invalid cases (e.g., decrement in C++). */ 4068tree 4069boolean_increment (enum tree_code code, tree arg) 4070{ 4071 tree val; 4072 tree true_res = boolean_true_node; 4073 4074 arg = stabilize_reference (arg); 4075 switch (code) 4076 { 4077 case PREINCREMENT_EXPR: 4078 val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res); 4079 break; 4080 case POSTINCREMENT_EXPR: 4081 val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res); 4082 arg = save_expr (arg); 4083 val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg); 4084 val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val); 4085 break; 4086 case PREDECREMENT_EXPR: 4087 val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, 4088 invert_truthvalue (arg)); 4089 break; 4090 case POSTDECREMENT_EXPR: 4091 val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, 4092 invert_truthvalue (arg)); 4093 arg = save_expr (arg); 4094 val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg); 4095 val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val); 4096 break; 4097 default: 4098 gcc_unreachable (); 4099 } 4100 TREE_SIDE_EFFECTS (val) = 1; 4101 return val; 4102} 4103 4104/* Built-in macros for stddef.h, that require macros defined in this 4105 file. */ 4106void 4107c_stddef_cpp_builtins(void) 4108{ 4109 builtin_define_with_value ("__SIZE_TYPE__", SIZE_TYPE, 0); 4110 builtin_define_with_value ("__PTRDIFF_TYPE__", PTRDIFF_TYPE, 0); 4111 builtin_define_with_value ("__WCHAR_TYPE__", MODIFIED_WCHAR_TYPE, 0); 4112 builtin_define_with_value ("__WINT_TYPE__", WINT_TYPE, 0); 4113 builtin_define_with_value ("__INTMAX_TYPE__", INTMAX_TYPE, 0); 4114 builtin_define_with_value ("__UINTMAX_TYPE__", UINTMAX_TYPE, 0); 4115} 4116 4117static void 4118c_init_attributes (void) 4119{ 4120 /* Fill in the built_in_attributes array. */ 4121#define DEF_ATTR_NULL_TREE(ENUM) \ 4122 built_in_attributes[(int) ENUM] = NULL_TREE; 4123#define DEF_ATTR_INT(ENUM, VALUE) \ 4124 built_in_attributes[(int) ENUM] = build_int_cst (NULL_TREE, VALUE); 4125#define DEF_ATTR_IDENT(ENUM, STRING) \ 4126 built_in_attributes[(int) ENUM] = get_identifier (STRING); 4127#define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) \ 4128 built_in_attributes[(int) ENUM] \ 4129 = tree_cons (built_in_attributes[(int) PURPOSE], \ 4130 built_in_attributes[(int) VALUE], \ 4131 built_in_attributes[(int) CHAIN]); 4132#include "builtin-attrs.def" 4133#undef DEF_ATTR_NULL_TREE 4134#undef DEF_ATTR_INT 4135#undef DEF_ATTR_IDENT 4136#undef DEF_ATTR_TREE_LIST 4137} 4138 4139/* Attribute handlers common to C front ends. */ 4140 4141/* Handle a "packed" attribute; arguments as in 4142 struct attribute_spec.handler. */ 4143 4144static tree 4145handle_packed_attribute (tree *node, tree name, tree ARG_UNUSED (args), 4146 int flags, bool *no_add_attrs) 4147{ 4148 if (TYPE_P (*node)) 4149 { 4150 if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE)) 4151 *node = build_variant_type_copy (*node); 4152 TYPE_PACKED (*node) = 1; 4153 } 4154 else if (TREE_CODE (*node) == FIELD_DECL) 4155 { 4156 if (TYPE_ALIGN (TREE_TYPE (*node)) <= BITS_PER_UNIT) 4157 warning (OPT_Wattributes, 4158 "%qE attribute ignored for field of type %qT", 4159 name, TREE_TYPE (*node)); 4160 else 4161 DECL_PACKED (*node) = 1; 4162 } 4163 /* We can't set DECL_PACKED for a VAR_DECL, because the bit is 4164 used for DECL_REGISTER. It wouldn't mean anything anyway. 4165 We can't set DECL_PACKED on the type of a TYPE_DECL, because 4166 that changes what the typedef is typing. */ 4167 else 4168 { 4169 warning (OPT_Wattributes, "%qE attribute ignored", name); 4170 *no_add_attrs = true; 4171 } 4172 4173 return NULL_TREE; 4174} 4175 4176/* Handle a "nocommon" attribute; arguments as in 4177 struct attribute_spec.handler. */ 4178 4179static tree 4180handle_nocommon_attribute (tree *node, tree name, 4181 tree ARG_UNUSED (args), 4182 int ARG_UNUSED (flags), bool *no_add_attrs) 4183{ 4184 if (TREE_CODE (*node) == VAR_DECL) 4185 DECL_COMMON (*node) = 0; 4186 else 4187 { 4188 warning (OPT_Wattributes, "%qE attribute ignored", name); 4189 *no_add_attrs = true; 4190 } 4191 4192 return NULL_TREE; 4193} 4194 4195/* Handle a "common" attribute; arguments as in 4196 struct attribute_spec.handler. */ 4197 4198static tree 4199handle_common_attribute (tree *node, tree name, tree ARG_UNUSED (args), 4200 int ARG_UNUSED (flags), bool *no_add_attrs) 4201{ 4202 if (TREE_CODE (*node) == VAR_DECL) 4203 DECL_COMMON (*node) = 1; 4204 else 4205 { 4206 warning (OPT_Wattributes, "%qE attribute ignored", name); 4207 *no_add_attrs = true; 4208 } 4209 4210 return NULL_TREE; 4211} 4212 4213/* Handle a "noreturn" attribute; arguments as in 4214 struct attribute_spec.handler. */ 4215 4216static tree 4217handle_noreturn_attribute (tree *node, tree name, tree ARG_UNUSED (args), 4218 int ARG_UNUSED (flags), bool *no_add_attrs) 4219{ 4220 tree type = TREE_TYPE (*node); 4221 4222 /* See FIXME comment in c_common_attribute_table. */ 4223 if (TREE_CODE (*node) == FUNCTION_DECL) 4224 TREE_THIS_VOLATILE (*node) = 1; 4225 else if (TREE_CODE (type) == POINTER_TYPE 4226 && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE) 4227 TREE_TYPE (*node) 4228 = build_pointer_type 4229 (build_type_variant (TREE_TYPE (type), 4230 TYPE_READONLY (TREE_TYPE (type)), 1)); 4231 else 4232 { 4233 warning (OPT_Wattributes, "%qE attribute ignored", name); 4234 *no_add_attrs = true; 4235 } 4236 4237 return NULL_TREE; 4238} 4239 4240/* Handle a "noinline" attribute; arguments as in 4241 struct attribute_spec.handler. */ 4242 4243static tree 4244handle_noinline_attribute (tree *node, tree name, 4245 tree ARG_UNUSED (args), 4246 int ARG_UNUSED (flags), bool *no_add_attrs) 4247{ 4248 if (TREE_CODE (*node) == FUNCTION_DECL) 4249 DECL_UNINLINABLE (*node) = 1; 4250 else 4251 { 4252 warning (OPT_Wattributes, "%qE attribute ignored", name); 4253 *no_add_attrs = true; 4254 } 4255 4256 return NULL_TREE; 4257} 4258 4259/* Handle a "always_inline" attribute; arguments as in 4260 struct attribute_spec.handler. */ 4261 4262static tree 4263handle_always_inline_attribute (tree *node, tree name, 4264 tree ARG_UNUSED (args), 4265 int ARG_UNUSED (flags), 4266 bool *no_add_attrs) 4267{ 4268 if (TREE_CODE (*node) == FUNCTION_DECL) 4269 { 4270 /* Do nothing else, just set the attribute. We'll get at 4271 it later with lookup_attribute. */ 4272 } 4273 else 4274 { 4275 warning (OPT_Wattributes, "%qE attribute ignored", name); 4276 *no_add_attrs = true; 4277 } 4278 4279 return NULL_TREE; 4280} 4281 4282/* Handle a "gnu_inline" attribute; arguments as in 4283 struct attribute_spec.handler. */ 4284 4285static tree 4286handle_gnu_inline_attribute (tree *node, tree name, 4287 tree ARG_UNUSED (args), 4288 int ARG_UNUSED (flags), 4289 bool *no_add_attrs) 4290{ 4291 if (TREE_CODE (*node) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (*node)) 4292 { 4293 /* Do nothing else, just set the attribute. We'll get at 4294 it later with lookup_attribute. */ 4295 } 4296 else 4297 { 4298 warning (OPT_Wattributes, "%qE attribute ignored", name); 4299 *no_add_attrs = true; 4300 } 4301 4302 return NULL_TREE; 4303} 4304 4305/* Handle a "flatten" attribute; arguments as in 4306 struct attribute_spec.handler. */ 4307 4308static tree 4309handle_flatten_attribute (tree *node, tree name, 4310 tree args ATTRIBUTE_UNUSED, 4311 int flags ATTRIBUTE_UNUSED, bool *no_add_attrs) 4312{ 4313 if (TREE_CODE (*node) == FUNCTION_DECL) 4314 /* Do nothing else, just set the attribute. We'll get at 4315 it later with lookup_attribute. */ 4316 ; 4317 else 4318 { 4319 warning (OPT_Wattributes, "%qE attribute ignored", name); 4320 *no_add_attrs = true; 4321 } 4322 4323 return NULL_TREE; 4324} 4325 4326 4327/* Handle a "used" attribute; arguments as in 4328 struct attribute_spec.handler. */ 4329 4330static tree 4331handle_used_attribute (tree *pnode, tree name, tree ARG_UNUSED (args), 4332 int ARG_UNUSED (flags), bool *no_add_attrs) 4333{ 4334 tree node = *pnode; 4335 4336 if (TREE_CODE (node) == FUNCTION_DECL 4337 || (TREE_CODE (node) == VAR_DECL && TREE_STATIC (node))) 4338 { 4339 TREE_USED (node) = 1; 4340 DECL_PRESERVE_P (node) = 1; 4341 } 4342 else 4343 { 4344 warning (OPT_Wattributes, "%qE attribute ignored", name); 4345 *no_add_attrs = true; 4346 } 4347 4348 return NULL_TREE; 4349} 4350 4351/* Handle a "unused" attribute; arguments as in 4352 struct attribute_spec.handler. */ 4353 4354static tree 4355handle_unused_attribute (tree *node, tree name, tree ARG_UNUSED (args), 4356 int flags, bool *no_add_attrs) 4357{ 4358 if (DECL_P (*node)) 4359 { 4360 tree decl = *node; 4361 4362 if (TREE_CODE (decl) == PARM_DECL 4363 || TREE_CODE (decl) == VAR_DECL 4364 || TREE_CODE (decl) == FUNCTION_DECL 4365 || TREE_CODE (decl) == LABEL_DECL 4366 || TREE_CODE (decl) == TYPE_DECL) 4367 TREE_USED (decl) = 1; 4368 else 4369 { 4370 warning (OPT_Wattributes, "%qE attribute ignored", name); 4371 *no_add_attrs = true; 4372 } 4373 } 4374 else 4375 { 4376 if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE)) 4377 *node = build_variant_type_copy (*node); 4378 TREE_USED (*node) = 1; 4379 } 4380 4381 return NULL_TREE; 4382} 4383 4384/* Handle a "externally_visible" attribute; arguments as in 4385 struct attribute_spec.handler. */ 4386 4387static tree 4388handle_externally_visible_attribute (tree *pnode, tree name, 4389 tree ARG_UNUSED (args), 4390 int ARG_UNUSED (flags), 4391 bool *no_add_attrs) 4392{ 4393 tree node = *pnode; 4394 4395 if (TREE_CODE (node) == FUNCTION_DECL || TREE_CODE (node) == VAR_DECL) 4396 { 4397 if ((!TREE_STATIC (node) && TREE_CODE (node) != FUNCTION_DECL 4398 && !DECL_EXTERNAL (node)) || !TREE_PUBLIC (node)) 4399 { 4400 warning (OPT_Wattributes, 4401 "%qE attribute have effect only on public objects", name); 4402 *no_add_attrs = true; 4403 } 4404 } 4405 else 4406 { 4407 warning (OPT_Wattributes, "%qE attribute ignored", name); 4408 *no_add_attrs = true; 4409 } 4410 4411 return NULL_TREE; 4412} 4413 4414/* Handle a "const" attribute; arguments as in 4415 struct attribute_spec.handler. */ 4416 4417static tree 4418handle_const_attribute (tree *node, tree name, tree ARG_UNUSED (args), 4419 int ARG_UNUSED (flags), bool *no_add_attrs) 4420{ 4421 tree type = TREE_TYPE (*node); 4422 4423 /* See FIXME comment on noreturn in c_common_attribute_table. */ 4424 if (TREE_CODE (*node) == FUNCTION_DECL) 4425 TREE_READONLY (*node) = 1; 4426 else if (TREE_CODE (type) == POINTER_TYPE 4427 && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE) 4428 TREE_TYPE (*node) 4429 = build_pointer_type 4430 (build_type_variant (TREE_TYPE (type), 1, 4431 TREE_THIS_VOLATILE (TREE_TYPE (type)))); 4432 else 4433 { 4434 warning (OPT_Wattributes, "%qE attribute ignored", name); 4435 *no_add_attrs = true; 4436 } 4437 4438 return NULL_TREE; 4439} 4440 4441/* Handle a "transparent_union" attribute; arguments as in 4442 struct attribute_spec.handler. */ 4443 4444static tree 4445handle_transparent_union_attribute (tree *node, tree name, 4446 tree ARG_UNUSED (args), int flags, 4447 bool *no_add_attrs) 4448{ 4449 tree type = NULL; 4450 4451 *no_add_attrs = true; 4452 4453 if (DECL_P (*node)) 4454 { 4455 if (TREE_CODE (*node) != TYPE_DECL) 4456 goto ignored; 4457 node = &TREE_TYPE (*node); 4458 type = *node; 4459 } 4460 else if (TYPE_P (*node)) 4461 type = *node; 4462 else 4463 goto ignored; 4464 4465 if (TREE_CODE (type) == UNION_TYPE) 4466 { 4467 /* When IN_PLACE is set, leave the check for FIELDS and MODE to 4468 the code in finish_struct. */ 4469 if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE)) 4470 { 4471 if (TYPE_FIELDS (type) == NULL_TREE 4472 || TYPE_MODE (type) != DECL_MODE (TYPE_FIELDS (type))) 4473 goto ignored; 4474 4475 /* A type variant isn't good enough, since we don't a cast 4476 to such a type removed as a no-op. */ 4477 *node = type = build_duplicate_type (type); 4478 } 4479 4480 TYPE_TRANSPARENT_UNION (type) = 1; 4481 return NULL_TREE; 4482 } 4483 4484 ignored: 4485 warning (OPT_Wattributes, "%qE attribute ignored", name); 4486 return NULL_TREE; 4487} 4488 4489/* Handle a "constructor" attribute; arguments as in 4490 struct attribute_spec.handler. */ 4491 4492static tree 4493handle_constructor_attribute (tree *node, tree name, 4494 tree ARG_UNUSED (args), 4495 int ARG_UNUSED (flags), 4496 bool *no_add_attrs) 4497{ 4498 tree decl = *node; 4499 tree type = TREE_TYPE (decl); 4500 4501 if (TREE_CODE (decl) == FUNCTION_DECL 4502 && TREE_CODE (type) == FUNCTION_TYPE 4503 && decl_function_context (decl) == 0) 4504 { 4505 DECL_STATIC_CONSTRUCTOR (decl) = 1; 4506 TREE_USED (decl) = 1; 4507 } 4508 else 4509 { 4510 warning (OPT_Wattributes, "%qE attribute ignored", name); 4511 *no_add_attrs = true; 4512 } 4513 4514 return NULL_TREE; 4515} 4516 4517/* Handle a "destructor" attribute; arguments as in 4518 struct attribute_spec.handler. */ 4519 4520static tree 4521handle_destructor_attribute (tree *node, tree name, 4522 tree ARG_UNUSED (args), 4523 int ARG_UNUSED (flags), 4524 bool *no_add_attrs) 4525{ 4526 tree decl = *node; 4527 tree type = TREE_TYPE (decl); 4528 4529 if (TREE_CODE (decl) == FUNCTION_DECL 4530 && TREE_CODE (type) == FUNCTION_TYPE 4531 && decl_function_context (decl) == 0) 4532 { 4533 DECL_STATIC_DESTRUCTOR (decl) = 1; 4534 TREE_USED (decl) = 1; 4535 } 4536 else 4537 { 4538 warning (OPT_Wattributes, "%qE attribute ignored", name); 4539 *no_add_attrs = true; 4540 } 4541 4542 return NULL_TREE; 4543} 4544 4545/* Handle a "mode" attribute; arguments as in 4546 struct attribute_spec.handler. */ 4547 4548static tree 4549handle_mode_attribute (tree *node, tree name, tree args, 4550 int ARG_UNUSED (flags), bool *no_add_attrs) 4551{ 4552 tree type = *node; 4553 4554 *no_add_attrs = true; 4555 4556 if (TREE_CODE (TREE_VALUE (args)) != IDENTIFIER_NODE) 4557 warning (OPT_Wattributes, "%qE attribute ignored", name); 4558 else 4559 { 4560 int j; 4561 const char *p = IDENTIFIER_POINTER (TREE_VALUE (args)); 4562 int len = strlen (p); 4563 enum machine_mode mode = VOIDmode; 4564 tree typefm; 4565 bool valid_mode; 4566 4567 if (len > 4 && p[0] == '_' && p[1] == '_' 4568 && p[len - 1] == '_' && p[len - 2] == '_') 4569 { 4570 char *newp = (char *) alloca (len - 1); 4571 4572 strcpy (newp, &p[2]); 4573 newp[len - 4] = '\0'; 4574 p = newp; 4575 } 4576 4577 /* Change this type to have a type with the specified mode. 4578 First check for the special modes. */ 4579 if (!strcmp (p, "byte")) 4580 mode = byte_mode; 4581 else if (!strcmp (p, "word")) 4582 mode = word_mode; 4583 else if (!strcmp (p, "pointer")) 4584 mode = ptr_mode; 4585 else 4586 for (j = 0; j < NUM_MACHINE_MODES; j++) 4587 if (!strcmp (p, GET_MODE_NAME (j))) 4588 { 4589 mode = (enum machine_mode) j; 4590 break; 4591 } 4592 4593 if (mode == VOIDmode) 4594 { 4595 error ("unknown machine mode %qs", p); 4596 return NULL_TREE; 4597 } 4598 4599 valid_mode = false; 4600 switch (GET_MODE_CLASS (mode)) 4601 { 4602 case MODE_INT: 4603 case MODE_PARTIAL_INT: 4604 case MODE_FLOAT: 4605 case MODE_DECIMAL_FLOAT: 4606 valid_mode = targetm.scalar_mode_supported_p (mode); 4607 break; 4608 4609 case MODE_COMPLEX_INT: 4610 case MODE_COMPLEX_FLOAT: 4611 valid_mode = targetm.scalar_mode_supported_p (GET_MODE_INNER (mode)); 4612 break; 4613 4614 case MODE_VECTOR_INT: 4615 case MODE_VECTOR_FLOAT: 4616 warning (OPT_Wattributes, "specifying vector types with " 4617 "__attribute__ ((mode)) is deprecated"); 4618 warning (OPT_Wattributes, 4619 "use __attribute__ ((vector_size)) instead"); 4620 valid_mode = vector_mode_valid_p (mode); 4621 break; 4622 4623 default: 4624 break; 4625 } 4626 if (!valid_mode) 4627 { 4628 error ("unable to emulate %qs", p); 4629 return NULL_TREE; 4630 } 4631 4632 if (POINTER_TYPE_P (type)) 4633 { 4634 tree (*fn)(tree, enum machine_mode, bool); 4635 4636 if (!targetm.valid_pointer_mode (mode)) 4637 { 4638 error ("invalid pointer mode %qs", p); 4639 return NULL_TREE; 4640 } 4641 4642 if (TREE_CODE (type) == POINTER_TYPE) 4643 fn = build_pointer_type_for_mode; 4644 else 4645 fn = build_reference_type_for_mode; 4646 typefm = fn (TREE_TYPE (type), mode, false); 4647 } 4648 else 4649 typefm = lang_hooks.types.type_for_mode (mode, TYPE_UNSIGNED (type)); 4650 4651 if (typefm == NULL_TREE) 4652 { 4653 error ("no data type for mode %qs", p); 4654 return NULL_TREE; 4655 } 4656 else if (TREE_CODE (type) == ENUMERAL_TYPE) 4657 { 4658 /* For enumeral types, copy the precision from the integer 4659 type returned above. If not an INTEGER_TYPE, we can't use 4660 this mode for this type. */ 4661 if (TREE_CODE (typefm) != INTEGER_TYPE) 4662 { 4663 error ("cannot use mode %qs for enumeral types", p); 4664 return NULL_TREE; 4665 } 4666 4667 if (flags & ATTR_FLAG_TYPE_IN_PLACE) 4668 { 4669 TYPE_PRECISION (type) = TYPE_PRECISION (typefm); 4670 typefm = type; 4671 } 4672 else 4673 { 4674 /* We cannot build a type variant, as there's code that assumes 4675 that TYPE_MAIN_VARIANT has the same mode. This includes the 4676 debug generators. Instead, create a subrange type. This 4677 results in all of the enumeral values being emitted only once 4678 in the original, and the subtype gets them by reference. */ 4679 if (TYPE_UNSIGNED (type)) 4680 typefm = make_unsigned_type (TYPE_PRECISION (typefm)); 4681 else 4682 typefm = make_signed_type (TYPE_PRECISION (typefm)); 4683 TREE_TYPE (typefm) = type; 4684 } 4685 } 4686 else if (VECTOR_MODE_P (mode) 4687 ? TREE_CODE (type) != TREE_CODE (TREE_TYPE (typefm)) 4688 : TREE_CODE (type) != TREE_CODE (typefm)) 4689 { 4690 error ("mode %qs applied to inappropriate type", p); 4691 return NULL_TREE; 4692 } 4693 4694 *node = typefm; 4695 } 4696 4697 return NULL_TREE; 4698} 4699 4700/* Handle a "section" attribute; arguments as in 4701 struct attribute_spec.handler. */ 4702 4703static tree 4704handle_section_attribute (tree *node, tree ARG_UNUSED (name), tree args, 4705 int ARG_UNUSED (flags), bool *no_add_attrs) 4706{ 4707 tree decl = *node; 4708 4709 if (targetm.have_named_sections) 4710 { 4711 user_defined_section_attribute = true; 4712 4713 if ((TREE_CODE (decl) == FUNCTION_DECL 4714 || TREE_CODE (decl) == VAR_DECL) 4715 && TREE_CODE (TREE_VALUE (args)) == STRING_CST) 4716 { 4717 if (TREE_CODE (decl) == VAR_DECL 4718 && current_function_decl != NULL_TREE 4719 && !TREE_STATIC (decl)) 4720 { 4721 error ("%Jsection attribute cannot be specified for " 4722 "local variables", decl); 4723 *no_add_attrs = true; 4724 } 4725 4726 /* The decl may have already been given a section attribute 4727 from a previous declaration. Ensure they match. */ 4728 else if (DECL_SECTION_NAME (decl) != NULL_TREE 4729 && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)), 4730 TREE_STRING_POINTER (TREE_VALUE (args))) != 0) 4731 { 4732 error ("section of %q+D conflicts with previous declaration", 4733 *node); 4734 *no_add_attrs = true; 4735 } 4736 else 4737 DECL_SECTION_NAME (decl) = TREE_VALUE (args); 4738 } 4739 else 4740 { 4741 error ("section attribute not allowed for %q+D", *node); 4742 *no_add_attrs = true; 4743 } 4744 } 4745 else 4746 { 4747 error ("%Jsection attributes are not supported for this target", *node); 4748 *no_add_attrs = true; 4749 } 4750 4751 return NULL_TREE; 4752} 4753 4754/* Handle a "aligned" attribute; arguments as in 4755 struct attribute_spec.handler. */ 4756 4757static tree 4758handle_aligned_attribute (tree *node, tree ARG_UNUSED (name), tree args, 4759 int flags, bool *no_add_attrs) 4760{ 4761 tree decl = NULL_TREE; 4762 tree *type = NULL; 4763 int is_type = 0; 4764 tree align_expr = (args ? TREE_VALUE (args) 4765 : size_int (BIGGEST_ALIGNMENT / BITS_PER_UNIT)); 4766 int i; 4767 4768 if (DECL_P (*node)) 4769 { 4770 decl = *node; 4771 type = &TREE_TYPE (decl); 4772 is_type = TREE_CODE (*node) == TYPE_DECL; 4773 } 4774 else if (TYPE_P (*node)) 4775 type = node, is_type = 1; 4776 4777 if (TREE_CODE (align_expr) != INTEGER_CST) 4778 { 4779 error ("requested alignment is not a constant"); 4780 *no_add_attrs = true; 4781 } 4782 else if ((i = tree_log2 (align_expr)) == -1) 4783 { 4784 error ("requested alignment is not a power of 2"); 4785 *no_add_attrs = true; 4786 } 4787 else if (i > HOST_BITS_PER_INT - 2) 4788 { 4789 error ("requested alignment is too large"); 4790 *no_add_attrs = true; 4791 } 4792 else if (is_type) 4793 { 4794 /* If we have a TYPE_DECL, then copy the type, so that we 4795 don't accidentally modify a builtin type. See pushdecl. */ 4796 if (decl && TREE_TYPE (decl) != error_mark_node 4797 && DECL_ORIGINAL_TYPE (decl) == NULL_TREE) 4798 { 4799 tree tt = TREE_TYPE (decl); 4800 *type = build_variant_type_copy (*type); 4801 DECL_ORIGINAL_TYPE (decl) = tt; 4802 TYPE_NAME (*type) = decl; 4803 TREE_USED (*type) = TREE_USED (decl); 4804 TREE_TYPE (decl) = *type; 4805 } 4806 else if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE)) 4807 *type = build_variant_type_copy (*type); 4808 4809 TYPE_ALIGN (*type) = (1 << i) * BITS_PER_UNIT; 4810 TYPE_USER_ALIGN (*type) = 1; 4811 } 4812 else if (! VAR_OR_FUNCTION_DECL_P (decl) 4813 && TREE_CODE (decl) != FIELD_DECL) 4814 { 4815 error ("alignment may not be specified for %q+D", decl); 4816 *no_add_attrs = true; 4817 } 4818 else if (TREE_CODE (decl) == FUNCTION_DECL 4819 && DECL_ALIGN (decl) > (1 << i) * BITS_PER_UNIT) 4820 { 4821 if (DECL_USER_ALIGN (decl)) 4822 error ("alignment for %q+D was previously specified as %d " 4823 "and may not be decreased", decl, 4824 DECL_ALIGN (decl) / BITS_PER_UNIT); 4825 else 4826 error ("alignment for %q+D must be at least %d", decl, 4827 DECL_ALIGN (decl) / BITS_PER_UNIT); 4828 *no_add_attrs = true; 4829 } 4830 else 4831 { 4832 DECL_ALIGN (decl) = (1 << i) * BITS_PER_UNIT; 4833 DECL_USER_ALIGN (decl) = 1; 4834 } 4835 4836 return NULL_TREE; 4837} 4838 4839/* Handle a "weak" attribute; arguments as in 4840 struct attribute_spec.handler. */ 4841 4842static tree 4843handle_weak_attribute (tree *node, tree name, 4844 tree ARG_UNUSED (args), 4845 int ARG_UNUSED (flags), 4846 bool * ARG_UNUSED (no_add_attrs)) 4847{ 4848 if (TREE_CODE (*node) == FUNCTION_DECL 4849 || TREE_CODE (*node) == VAR_DECL) 4850 declare_weak (*node); 4851 else 4852 warning (OPT_Wattributes, "%qE attribute ignored", name); 4853 4854 4855 return NULL_TREE; 4856} 4857 4858/* Handle an "alias" attribute; arguments as in 4859 struct attribute_spec.handler. */ 4860 4861static tree 4862handle_alias_attribute (tree *node, tree name, tree args, 4863 int ARG_UNUSED (flags), bool *no_add_attrs) 4864{ 4865 tree decl = *node; 4866 4867 if ((TREE_CODE (decl) == FUNCTION_DECL && DECL_INITIAL (decl)) 4868 || (TREE_CODE (decl) != FUNCTION_DECL 4869 && TREE_PUBLIC (decl) && !DECL_EXTERNAL (decl)) 4870 /* A static variable declaration is always a tentative definition, 4871 but the alias is a non-tentative definition which overrides. */ 4872 || (TREE_CODE (decl) != FUNCTION_DECL 4873 && ! TREE_PUBLIC (decl) && DECL_INITIAL (decl))) 4874 { 4875 error ("%q+D defined both normally and as an alias", decl); 4876 *no_add_attrs = true; 4877 } 4878 4879 /* Note that the very first time we process a nested declaration, 4880 decl_function_context will not be set. Indeed, *would* never 4881 be set except for the DECL_INITIAL/DECL_EXTERNAL frobbery that 4882 we do below. After such frobbery, pushdecl would set the context. 4883 In any case, this is never what we want. */ 4884 else if (decl_function_context (decl) == 0 && current_function_decl == NULL) 4885 { 4886 tree id; 4887 4888 id = TREE_VALUE (args); 4889 if (TREE_CODE (id) != STRING_CST) 4890 { 4891 error ("alias argument not a string"); 4892 *no_add_attrs = true; 4893 return NULL_TREE; 4894 } 4895 id = get_identifier (TREE_STRING_POINTER (id)); 4896 /* This counts as a use of the object pointed to. */ 4897 TREE_USED (id) = 1; 4898 4899 if (TREE_CODE (decl) == FUNCTION_DECL) 4900 DECL_INITIAL (decl) = error_mark_node; 4901 else 4902 { 4903 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl))) 4904 DECL_EXTERNAL (decl) = 1; 4905 else 4906 DECL_EXTERNAL (decl) = 0; 4907 TREE_STATIC (decl) = 1; 4908 } 4909 } 4910 else 4911 { 4912 warning (OPT_Wattributes, "%qE attribute ignored", name); 4913 *no_add_attrs = true; 4914 } 4915 4916 return NULL_TREE; 4917} 4918 4919/* Handle a "weakref" attribute; arguments as in struct 4920 attribute_spec.handler. */ 4921 4922static tree 4923handle_weakref_attribute (tree *node, tree ARG_UNUSED (name), tree args, 4924 int flags, bool *no_add_attrs) 4925{ 4926 tree attr = NULL_TREE; 4927 4928 /* We must ignore the attribute when it is associated with 4929 local-scoped decls, since attribute alias is ignored and many 4930 such symbols do not even have a DECL_WEAK field. */ 4931 if (decl_function_context (*node) || current_function_decl) 4932 { 4933 warning (OPT_Wattributes, "%qE attribute ignored", name); 4934 *no_add_attrs = true; 4935 return NULL_TREE; 4936 } 4937 4938 /* The idea here is that `weakref("name")' mutates into `weakref, 4939 alias("name")', and weakref without arguments, in turn, 4940 implicitly adds weak. */ 4941 4942 if (args) 4943 { 4944 attr = tree_cons (get_identifier ("alias"), args, attr); 4945 attr = tree_cons (get_identifier ("weakref"), NULL_TREE, attr); 4946 4947 *no_add_attrs = true; 4948 4949 decl_attributes (node, attr, flags); 4950 } 4951 else 4952 { 4953 if (lookup_attribute ("alias", DECL_ATTRIBUTES (*node))) 4954 error ("%Jweakref attribute must appear before alias attribute", 4955 *node); 4956 4957 /* Can't call declare_weak because it wants this to be TREE_PUBLIC, 4958 and that isn't supported; and because it wants to add it to 4959 the list of weak decls, which isn't helpful. */ 4960 DECL_WEAK (*node) = 1; 4961 } 4962 4963 return NULL_TREE; 4964} 4965 4966/* Handle an "visibility" attribute; arguments as in 4967 struct attribute_spec.handler. */ 4968 4969static tree 4970handle_visibility_attribute (tree *node, tree name, tree args, 4971 int ARG_UNUSED (flags), 4972 bool *ARG_UNUSED (no_add_attrs)) 4973{ 4974 tree decl = *node; 4975 tree id = TREE_VALUE (args); 4976 enum symbol_visibility vis; 4977 4978 if (TYPE_P (*node)) 4979 { 4980 if (TREE_CODE (*node) == ENUMERAL_TYPE) 4981 /* OK */; 4982 else if (TREE_CODE (*node) != RECORD_TYPE && TREE_CODE (*node) != UNION_TYPE) 4983 { 4984 warning (OPT_Wattributes, "%qE attribute ignored on non-class types", 4985 name); 4986 return NULL_TREE; 4987 } 4988 else if (TYPE_FIELDS (*node)) 4989 { 4990 error ("%qE attribute ignored because %qT is already defined", 4991 name, *node); 4992 return NULL_TREE; 4993 } 4994 } 4995 else if (decl_function_context (decl) != 0 || !TREE_PUBLIC (decl)) 4996 { 4997 warning (OPT_Wattributes, "%qE attribute ignored", name); 4998 return NULL_TREE; 4999 } 5000 5001 if (TREE_CODE (id) != STRING_CST) 5002 { 5003 error ("visibility argument not a string"); 5004 return NULL_TREE; 5005 } 5006 5007 /* If this is a type, set the visibility on the type decl. */ 5008 if (TYPE_P (decl)) 5009 { 5010 decl = TYPE_NAME (decl); 5011 if (!decl) 5012 return NULL_TREE; 5013 if (TREE_CODE (decl) == IDENTIFIER_NODE) 5014 { 5015 warning (OPT_Wattributes, "%qE attribute ignored on types", 5016 name); 5017 return NULL_TREE; 5018 } 5019 } 5020 5021 if (strcmp (TREE_STRING_POINTER (id), "default") == 0) 5022 vis = VISIBILITY_DEFAULT; 5023 else if (strcmp (TREE_STRING_POINTER (id), "internal") == 0) 5024 vis = VISIBILITY_INTERNAL; 5025 else if (strcmp (TREE_STRING_POINTER (id), "hidden") == 0) 5026 vis = VISIBILITY_HIDDEN; 5027 else if (strcmp (TREE_STRING_POINTER (id), "protected") == 0) 5028 vis = VISIBILITY_PROTECTED; 5029 else 5030 { 5031 error ("visibility argument must be one of \"default\", \"hidden\", \"protected\" or \"internal\""); 5032 vis = VISIBILITY_DEFAULT; 5033 } 5034 5035 if (DECL_VISIBILITY_SPECIFIED (decl) 5036 && vis != DECL_VISIBILITY (decl) 5037 && lookup_attribute ("visibility", (TYPE_P (*node) 5038 ? TYPE_ATTRIBUTES (*node) 5039 : DECL_ATTRIBUTES (decl)))) 5040 error ("%qD redeclared with different visibility", decl); 5041 5042 DECL_VISIBILITY (decl) = vis; 5043 DECL_VISIBILITY_SPECIFIED (decl) = 1; 5044 5045 /* Go ahead and attach the attribute to the node as well. This is needed 5046 so we can determine whether we have VISIBILITY_DEFAULT because the 5047 visibility was not specified, or because it was explicitly overridden 5048 from the containing scope. */ 5049 5050 return NULL_TREE; 5051} 5052 5053/* Determine the ELF symbol visibility for DECL, which is either a 5054 variable or a function. It is an error to use this function if a 5055 definition of DECL is not available in this translation unit. 5056 Returns true if the final visibility has been determined by this 5057 function; false if the caller is free to make additional 5058 modifications. */ 5059 5060bool 5061c_determine_visibility (tree decl) 5062{ 5063 gcc_assert (TREE_CODE (decl) == VAR_DECL 5064 || TREE_CODE (decl) == FUNCTION_DECL); 5065 5066 /* If the user explicitly specified the visibility with an 5067 attribute, honor that. DECL_VISIBILITY will have been set during 5068 the processing of the attribute. We check for an explicit 5069 attribute, rather than just checking DECL_VISIBILITY_SPECIFIED, 5070 to distinguish the use of an attribute from the use of a "#pragma 5071 GCC visibility push(...)"; in the latter case we still want other 5072 considerations to be able to overrule the #pragma. */ 5073 if (lookup_attribute ("visibility", DECL_ATTRIBUTES (decl))) 5074 return true; 5075 5076 /* Anything that is exported must have default visibility. */ 5077 if (TARGET_DLLIMPORT_DECL_ATTRIBUTES 5078 && lookup_attribute ("dllexport", DECL_ATTRIBUTES (decl))) 5079 { 5080 DECL_VISIBILITY (decl) = VISIBILITY_DEFAULT; 5081 DECL_VISIBILITY_SPECIFIED (decl) = 1; 5082 return true; 5083 } 5084 5085 /* Set default visibility to whatever the user supplied with 5086 visibility_specified depending on #pragma GCC visibility. */ 5087 if (!DECL_VISIBILITY_SPECIFIED (decl)) 5088 { 5089 DECL_VISIBILITY (decl) = default_visibility; 5090 DECL_VISIBILITY_SPECIFIED (decl) = visibility_options.inpragma; 5091 } 5092 return false; 5093} 5094 5095/* Handle an "tls_model" attribute; arguments as in 5096 struct attribute_spec.handler. */ 5097 5098static tree 5099handle_tls_model_attribute (tree *node, tree name, tree args, 5100 int ARG_UNUSED (flags), bool *no_add_attrs) 5101{ 5102 tree id; 5103 tree decl = *node; 5104 enum tls_model kind; 5105 5106 *no_add_attrs = true; 5107 5108 if (!DECL_THREAD_LOCAL_P (decl)) 5109 { 5110 warning (OPT_Wattributes, "%qE attribute ignored", name); 5111 return NULL_TREE; 5112 } 5113 5114 kind = DECL_TLS_MODEL (decl); 5115 id = TREE_VALUE (args); 5116 if (TREE_CODE (id) != STRING_CST) 5117 { 5118 error ("tls_model argument not a string"); 5119 return NULL_TREE; 5120 } 5121 5122 if (!strcmp (TREE_STRING_POINTER (id), "local-exec")) 5123 kind = TLS_MODEL_LOCAL_EXEC; 5124 else if (!strcmp (TREE_STRING_POINTER (id), "initial-exec")) 5125 kind = TLS_MODEL_INITIAL_EXEC; 5126 else if (!strcmp (TREE_STRING_POINTER (id), "local-dynamic")) 5127 kind = optimize ? TLS_MODEL_LOCAL_DYNAMIC : TLS_MODEL_GLOBAL_DYNAMIC; 5128 else if (!strcmp (TREE_STRING_POINTER (id), "global-dynamic")) 5129 kind = TLS_MODEL_GLOBAL_DYNAMIC; 5130 else 5131 error ("tls_model argument must be one of \"local-exec\", \"initial-exec\", \"local-dynamic\" or \"global-dynamic\""); 5132 5133 DECL_TLS_MODEL (decl) = kind; 5134 return NULL_TREE; 5135} 5136 5137/* Handle a "no_instrument_function" attribute; arguments as in 5138 struct attribute_spec.handler. */ 5139 5140static tree 5141handle_no_instrument_function_attribute (tree *node, tree name, 5142 tree ARG_UNUSED (args), 5143 int ARG_UNUSED (flags), 5144 bool *no_add_attrs) 5145{ 5146 tree decl = *node; 5147 5148 if (TREE_CODE (decl) != FUNCTION_DECL) 5149 { 5150 error ("%J%qE attribute applies only to functions", decl, name); 5151 *no_add_attrs = true; 5152 } 5153 else if (DECL_INITIAL (decl)) 5154 { 5155 error ("%Jcan%'t set %qE attribute after definition", decl, name); 5156 *no_add_attrs = true; 5157 } 5158 else 5159 DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (decl) = 1; 5160 5161 return NULL_TREE; 5162} 5163 5164/* Handle a "malloc" attribute; arguments as in 5165 struct attribute_spec.handler. */ 5166 5167static tree 5168handle_malloc_attribute (tree *node, tree name, tree ARG_UNUSED (args), 5169 int ARG_UNUSED (flags), bool *no_add_attrs) 5170{ 5171 if (TREE_CODE (*node) == FUNCTION_DECL 5172 && POINTER_TYPE_P (TREE_TYPE (TREE_TYPE (*node)))) 5173 DECL_IS_MALLOC (*node) = 1; 5174 else 5175 { 5176 warning (OPT_Wattributes, "%qE attribute ignored", name); 5177 *no_add_attrs = true; 5178 } 5179 5180 return NULL_TREE; 5181} 5182 5183/* Handle a "returns_twice" attribute; arguments as in 5184 struct attribute_spec.handler. */ 5185 5186static tree 5187handle_returns_twice_attribute (tree *node, tree name, tree ARG_UNUSED (args), 5188 int ARG_UNUSED (flags), bool *no_add_attrs) 5189{ 5190 if (TREE_CODE (*node) == FUNCTION_DECL) 5191 DECL_IS_RETURNS_TWICE (*node) = 1; 5192 else 5193 { 5194 warning (OPT_Wattributes, "%qE attribute ignored", name); 5195 *no_add_attrs = true; 5196 } 5197 5198 return NULL_TREE; 5199} 5200 5201/* Handle a "no_limit_stack" attribute; arguments as in 5202 struct attribute_spec.handler. */ 5203 5204static tree 5205handle_no_limit_stack_attribute (tree *node, tree name, 5206 tree ARG_UNUSED (args), 5207 int ARG_UNUSED (flags), 5208 bool *no_add_attrs) 5209{ 5210 tree decl = *node; 5211 5212 if (TREE_CODE (decl) != FUNCTION_DECL) 5213 { 5214 error ("%J%qE attribute applies only to functions", decl, name); 5215 *no_add_attrs = true; 5216 } 5217 else if (DECL_INITIAL (decl)) 5218 { 5219 error ("%Jcan%'t set %qE attribute after definition", decl, name); 5220 *no_add_attrs = true; 5221 } 5222 else 5223 DECL_NO_LIMIT_STACK (decl) = 1; 5224 5225 return NULL_TREE; 5226} 5227 5228/* Handle a "pure" attribute; arguments as in 5229 struct attribute_spec.handler. */ 5230 5231static tree 5232handle_pure_attribute (tree *node, tree name, tree ARG_UNUSED (args), 5233 int ARG_UNUSED (flags), bool *no_add_attrs) 5234{ 5235 if (TREE_CODE (*node) == FUNCTION_DECL) 5236 DECL_IS_PURE (*node) = 1; 5237 /* ??? TODO: Support types. */ 5238 else 5239 { 5240 warning (OPT_Wattributes, "%qE attribute ignored", name); 5241 *no_add_attrs = true; 5242 } 5243 5244 return NULL_TREE; 5245} 5246 5247/* Handle a "no vops" attribute; arguments as in 5248 struct attribute_spec.handler. */ 5249 5250static tree 5251handle_novops_attribute (tree *node, tree ARG_UNUSED (name), 5252 tree ARG_UNUSED (args), int ARG_UNUSED (flags), 5253 bool *ARG_UNUSED (no_add_attrs)) 5254{ 5255 gcc_assert (TREE_CODE (*node) == FUNCTION_DECL); 5256 DECL_IS_NOVOPS (*node) = 1; 5257 return NULL_TREE; 5258} 5259 5260/* Handle a "deprecated" attribute; arguments as in 5261 struct attribute_spec.handler. */ 5262 5263static tree 5264handle_deprecated_attribute (tree *node, tree name, 5265 tree ARG_UNUSED (args), int flags, 5266 bool *no_add_attrs) 5267{ 5268 tree type = NULL_TREE; 5269 int warn = 0; 5270 tree what = NULL_TREE; 5271 5272 if (DECL_P (*node)) 5273 { 5274 tree decl = *node; 5275 type = TREE_TYPE (decl); 5276 5277 if (TREE_CODE (decl) == TYPE_DECL 5278 || TREE_CODE (decl) == PARM_DECL 5279 || TREE_CODE (decl) == VAR_DECL 5280 || TREE_CODE (decl) == FUNCTION_DECL 5281 || TREE_CODE (decl) == FIELD_DECL) 5282 TREE_DEPRECATED (decl) = 1; 5283 else 5284 warn = 1; 5285 } 5286 else if (TYPE_P (*node)) 5287 { 5288 if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE)) 5289 *node = build_variant_type_copy (*node); 5290 TREE_DEPRECATED (*node) = 1; 5291 type = *node; 5292 } 5293 else 5294 warn = 1; 5295 5296 if (warn) 5297 { 5298 *no_add_attrs = true; 5299 if (type && TYPE_NAME (type)) 5300 { 5301 if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE) 5302 what = TYPE_NAME (*node); 5303 else if (TREE_CODE (TYPE_NAME (type)) == TYPE_DECL 5304 && DECL_NAME (TYPE_NAME (type))) 5305 what = DECL_NAME (TYPE_NAME (type)); 5306 } 5307 if (what) 5308 warning (OPT_Wattributes, "%qE attribute ignored for %qE", name, what); 5309 else 5310 warning (OPT_Wattributes, "%qE attribute ignored", name); 5311 } 5312 5313 return NULL_TREE; 5314} 5315 5316/* Handle a "vector_size" attribute; arguments as in 5317 struct attribute_spec.handler. */ 5318 5319static tree 5320handle_vector_size_attribute (tree *node, tree name, tree args, 5321 int ARG_UNUSED (flags), 5322 bool *no_add_attrs) 5323{ 5324 unsigned HOST_WIDE_INT vecsize, nunits; 5325 enum machine_mode orig_mode; 5326 tree type = *node, new_type, size; 5327 5328 *no_add_attrs = true; 5329 5330 size = TREE_VALUE (args); 5331 5332 if (!host_integerp (size, 1)) 5333 { 5334 warning (OPT_Wattributes, "%qE attribute ignored", name); 5335 return NULL_TREE; 5336 } 5337 5338 /* Get the vector size (in bytes). */ 5339 vecsize = tree_low_cst (size, 1); 5340 5341 /* We need to provide for vector pointers, vector arrays, and 5342 functions returning vectors. For example: 5343 5344 __attribute__((vector_size(16))) short *foo; 5345 5346 In this case, the mode is SI, but the type being modified is 5347 HI, so we need to look further. */ 5348 5349 while (POINTER_TYPE_P (type) 5350 || TREE_CODE (type) == FUNCTION_TYPE 5351 || TREE_CODE (type) == METHOD_TYPE 5352 || TREE_CODE (type) == ARRAY_TYPE) 5353 type = TREE_TYPE (type); 5354 5355 /* Get the mode of the type being modified. */ 5356 orig_mode = TYPE_MODE (type); 5357 5358 if (TREE_CODE (type) == RECORD_TYPE 5359 || TREE_CODE (type) == UNION_TYPE 5360 || TREE_CODE (type) == VECTOR_TYPE 5361 || (!SCALAR_FLOAT_MODE_P (orig_mode) 5362 && GET_MODE_CLASS (orig_mode) != MODE_INT) 5363 || !host_integerp (TYPE_SIZE_UNIT (type), 1)) 5364 { 5365 error ("invalid vector type for attribute %qE", name); 5366 return NULL_TREE; 5367 } 5368 5369 if (vecsize % tree_low_cst (TYPE_SIZE_UNIT (type), 1)) 5370 { 5371 error ("vector size not an integral multiple of component size"); 5372 return NULL; 5373 } 5374 5375 if (vecsize == 0) 5376 { 5377 error ("zero vector size"); 5378 return NULL; 5379 } 5380 5381 /* Calculate how many units fit in the vector. */ 5382 nunits = vecsize / tree_low_cst (TYPE_SIZE_UNIT (type), 1); 5383 if (nunits & (nunits - 1)) 5384 { 5385 error ("number of components of the vector not a power of two"); 5386 return NULL_TREE; 5387 } 5388 5389 new_type = build_vector_type (type, nunits); 5390 5391 /* Build back pointers if needed. */ 5392 *node = reconstruct_complex_type (*node, new_type); 5393 5394 return NULL_TREE; 5395} 5396 5397/* Handle the "nonnull" attribute. */ 5398static tree 5399handle_nonnull_attribute (tree *node, tree ARG_UNUSED (name), 5400 tree args, int ARG_UNUSED (flags), 5401 bool *no_add_attrs) 5402{ 5403 tree type = *node; 5404 unsigned HOST_WIDE_INT attr_arg_num; 5405 5406 /* If no arguments are specified, all pointer arguments should be 5407 non-null. Verify a full prototype is given so that the arguments 5408 will have the correct types when we actually check them later. */ 5409 if (!args) 5410 { 5411 if (!TYPE_ARG_TYPES (type)) 5412 { 5413 error ("nonnull attribute without arguments on a non-prototype"); 5414 *no_add_attrs = true; 5415 } 5416 return NULL_TREE; 5417 } 5418 5419 /* Argument list specified. Verify that each argument number references 5420 a pointer argument. */ 5421 for (attr_arg_num = 1; args; args = TREE_CHAIN (args)) 5422 { 5423 tree argument; 5424 unsigned HOST_WIDE_INT arg_num = 0, ck_num; 5425 5426 if (!get_nonnull_operand (TREE_VALUE (args), &arg_num)) 5427 { 5428 error ("nonnull argument has invalid operand number (argument %lu)", 5429 (unsigned long) attr_arg_num); 5430 *no_add_attrs = true; 5431 return NULL_TREE; 5432 } 5433 5434 argument = TYPE_ARG_TYPES (type); 5435 if (argument) 5436 { 5437 for (ck_num = 1; ; ck_num++) 5438 { 5439 if (!argument || ck_num == arg_num) 5440 break; 5441 argument = TREE_CHAIN (argument); 5442 } 5443 5444 if (!argument 5445 || TREE_CODE (TREE_VALUE (argument)) == VOID_TYPE) 5446 { 5447 error ("nonnull argument with out-of-range operand number (argument %lu, operand %lu)", 5448 (unsigned long) attr_arg_num, (unsigned long) arg_num); 5449 *no_add_attrs = true; 5450 return NULL_TREE; 5451 } 5452 5453 if (TREE_CODE (TREE_VALUE (argument)) != POINTER_TYPE) 5454 { 5455 error ("nonnull argument references non-pointer operand (argument %lu, operand %lu)", 5456 (unsigned long) attr_arg_num, (unsigned long) arg_num); 5457 *no_add_attrs = true; 5458 return NULL_TREE; 5459 } 5460 } 5461 } 5462 5463 return NULL_TREE; 5464} 5465 5466/* Check the argument list of a function call for null in argument slots 5467 that are marked as requiring a non-null pointer argument. */ 5468 5469static void 5470check_function_nonnull (tree attrs, tree params) 5471{ 5472 tree a, args, param; 5473 int param_num; 5474 5475 for (a = attrs; a; a = TREE_CHAIN (a)) 5476 { 5477 if (is_attribute_p ("nonnull", TREE_PURPOSE (a))) 5478 { 5479 args = TREE_VALUE (a); 5480 5481 /* Walk the argument list. If we encounter an argument number we 5482 should check for non-null, do it. If the attribute has no args, 5483 then every pointer argument is checked (in which case the check 5484 for pointer type is done in check_nonnull_arg). */ 5485 for (param = params, param_num = 1; ; 5486 param_num++, param = TREE_CHAIN (param)) 5487 { 5488 if (!param) 5489 break; 5490 if (!args || nonnull_check_p (args, param_num)) 5491 check_function_arguments_recurse (check_nonnull_arg, NULL, 5492 TREE_VALUE (param), 5493 param_num); 5494 } 5495 } 5496 } 5497} 5498 5499/* Check that the Nth argument of a function call (counting backwards 5500 from the end) is a (pointer)0. */ 5501 5502static void 5503check_function_sentinel (tree attrs, tree params, tree typelist) 5504{ 5505 tree attr = lookup_attribute ("sentinel", attrs); 5506 5507 if (attr) 5508 { 5509 /* Skip over the named arguments. */ 5510 while (typelist && params) 5511 { 5512 typelist = TREE_CHAIN (typelist); 5513 params = TREE_CHAIN (params); 5514 } 5515 5516 if (typelist || !params) 5517 warning (OPT_Wformat, 5518 "not enough variable arguments to fit a sentinel"); 5519 else 5520 { 5521 tree sentinel, end; 5522 unsigned pos = 0; 5523 5524 if (TREE_VALUE (attr)) 5525 { 5526 tree p = TREE_VALUE (TREE_VALUE (attr)); 5527 pos = TREE_INT_CST_LOW (p); 5528 } 5529 5530 sentinel = end = params; 5531 5532 /* Advance `end' ahead of `sentinel' by `pos' positions. */ 5533 while (pos > 0 && TREE_CHAIN (end)) 5534 { 5535 pos--; 5536 end = TREE_CHAIN (end); 5537 } 5538 if (pos > 0) 5539 { 5540 warning (OPT_Wformat, 5541 "not enough variable arguments to fit a sentinel"); 5542 return; 5543 } 5544 5545 /* Now advance both until we find the last parameter. */ 5546 while (TREE_CHAIN (end)) 5547 { 5548 end = TREE_CHAIN (end); 5549 sentinel = TREE_CHAIN (sentinel); 5550 } 5551 5552 /* Validate the sentinel. */ 5553 if ((!POINTER_TYPE_P (TREE_TYPE (TREE_VALUE (sentinel))) 5554 || !integer_zerop (TREE_VALUE (sentinel))) 5555 /* Although __null (in C++) is only an integer we allow it 5556 nevertheless, as we are guaranteed that it's exactly 5557 as wide as a pointer, and we don't want to force 5558 users to cast the NULL they have written there. 5559 We warn with -Wstrict-null-sentinel, though. */ 5560 && (warn_strict_null_sentinel 5561 || null_node != TREE_VALUE (sentinel))) 5562 warning (OPT_Wformat, "missing sentinel in function call"); 5563 } 5564 } 5565} 5566 5567/* Helper for check_function_nonnull; given a list of operands which 5568 must be non-null in ARGS, determine if operand PARAM_NUM should be 5569 checked. */ 5570 5571static bool 5572nonnull_check_p (tree args, unsigned HOST_WIDE_INT param_num) 5573{ 5574 unsigned HOST_WIDE_INT arg_num = 0; 5575 5576 for (; args; args = TREE_CHAIN (args)) 5577 { 5578 bool found = get_nonnull_operand (TREE_VALUE (args), &arg_num); 5579 5580 gcc_assert (found); 5581 5582 if (arg_num == param_num) 5583 return true; 5584 } 5585 return false; 5586} 5587 5588/* Check that the function argument PARAM (which is operand number 5589 PARAM_NUM) is non-null. This is called by check_function_nonnull 5590 via check_function_arguments_recurse. */ 5591 5592static void 5593check_nonnull_arg (void * ARG_UNUSED (ctx), tree param, 5594 unsigned HOST_WIDE_INT param_num) 5595{ 5596 /* Just skip checking the argument if it's not a pointer. This can 5597 happen if the "nonnull" attribute was given without an operand 5598 list (which means to check every pointer argument). */ 5599 5600 if (TREE_CODE (TREE_TYPE (param)) != POINTER_TYPE) 5601 return; 5602 5603 if (integer_zerop (param)) 5604 warning (OPT_Wnonnull, "null argument where non-null required " 5605 "(argument %lu)", (unsigned long) param_num); 5606} 5607 5608/* Helper for nonnull attribute handling; fetch the operand number 5609 from the attribute argument list. */ 5610 5611static bool 5612get_nonnull_operand (tree arg_num_expr, unsigned HOST_WIDE_INT *valp) 5613{ 5614 /* Verify the arg number is a constant. */ 5615 if (TREE_CODE (arg_num_expr) != INTEGER_CST 5616 || TREE_INT_CST_HIGH (arg_num_expr) != 0) 5617 return false; 5618 5619 *valp = TREE_INT_CST_LOW (arg_num_expr); 5620 return true; 5621} 5622 5623/* Handle a "nothrow" attribute; arguments as in 5624 struct attribute_spec.handler. */ 5625 5626static tree 5627handle_nothrow_attribute (tree *node, tree name, tree ARG_UNUSED (args), 5628 int ARG_UNUSED (flags), bool *no_add_attrs) 5629{ 5630 if (TREE_CODE (*node) == FUNCTION_DECL) 5631 TREE_NOTHROW (*node) = 1; 5632 /* ??? TODO: Support types. */ 5633 else 5634 { 5635 warning (OPT_Wattributes, "%qE attribute ignored", name); 5636 *no_add_attrs = true; 5637 } 5638 5639 return NULL_TREE; 5640} 5641 5642/* Handle a "cleanup" attribute; arguments as in 5643 struct attribute_spec.handler. */ 5644 5645static tree 5646handle_cleanup_attribute (tree *node, tree name, tree args, 5647 int ARG_UNUSED (flags), bool *no_add_attrs) 5648{ 5649 tree decl = *node; 5650 tree cleanup_id, cleanup_decl; 5651 5652 /* ??? Could perhaps support cleanups on TREE_STATIC, much like we do 5653 for global destructors in C++. This requires infrastructure that 5654 we don't have generically at the moment. It's also not a feature 5655 we'd be missing too much, since we do have attribute constructor. */ 5656 if (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl)) 5657 { 5658 warning (OPT_Wattributes, "%qE attribute ignored", name); 5659 *no_add_attrs = true; 5660 return NULL_TREE; 5661 } 5662 5663 /* Verify that the argument is a function in scope. */ 5664 /* ??? We could support pointers to functions here as well, if 5665 that was considered desirable. */ 5666 cleanup_id = TREE_VALUE (args); 5667 if (TREE_CODE (cleanup_id) != IDENTIFIER_NODE) 5668 { 5669 error ("cleanup argument not an identifier"); 5670 *no_add_attrs = true; 5671 return NULL_TREE; 5672 } 5673 cleanup_decl = lookup_name (cleanup_id); 5674 if (!cleanup_decl || TREE_CODE (cleanup_decl) != FUNCTION_DECL) 5675 { 5676 error ("cleanup argument not a function"); 5677 *no_add_attrs = true; 5678 return NULL_TREE; 5679 } 5680 5681 /* That the function has proper type is checked with the 5682 eventual call to build_function_call. */ 5683 5684 return NULL_TREE; 5685} 5686 5687/* Handle a "warn_unused_result" attribute. No special handling. */ 5688 5689static tree 5690handle_warn_unused_result_attribute (tree *node, tree name, 5691 tree ARG_UNUSED (args), 5692 int ARG_UNUSED (flags), bool *no_add_attrs) 5693{ 5694 /* Ignore the attribute for functions not returning any value. */ 5695 if (VOID_TYPE_P (TREE_TYPE (*node))) 5696 { 5697 warning (OPT_Wattributes, "%qE attribute ignored", name); 5698 *no_add_attrs = true; 5699 } 5700 5701 return NULL_TREE; 5702} 5703 5704/* Handle a "sentinel" attribute. */ 5705 5706static tree 5707handle_sentinel_attribute (tree *node, tree name, tree args, 5708 int ARG_UNUSED (flags), bool *no_add_attrs) 5709{ 5710 tree params = TYPE_ARG_TYPES (*node); 5711 5712 if (!params) 5713 { 5714 warning (OPT_Wattributes, 5715 "%qE attribute requires prototypes with named arguments", name); 5716 *no_add_attrs = true; 5717 } 5718 else 5719 { 5720 while (TREE_CHAIN (params)) 5721 params = TREE_CHAIN (params); 5722 5723 if (VOID_TYPE_P (TREE_VALUE (params))) 5724 { 5725 warning (OPT_Wattributes, 5726 "%qE attribute only applies to variadic functions", name); 5727 *no_add_attrs = true; 5728 } 5729 } 5730 5731 if (args) 5732 { 5733 tree position = TREE_VALUE (args); 5734 5735 if (TREE_CODE (position) != INTEGER_CST) 5736 { 5737 warning (0, "requested position is not an integer constant"); 5738 *no_add_attrs = true; 5739 } 5740 else 5741 { 5742 if (tree_int_cst_lt (position, integer_zero_node)) 5743 { 5744 warning (0, "requested position is less than zero"); 5745 *no_add_attrs = true; 5746 } 5747 } 5748 } 5749 5750 return NULL_TREE; 5751} 5752 5753/* Check for valid arguments being passed to a function. */ 5754void 5755check_function_arguments (tree attrs, tree params, tree typelist) 5756{ 5757 /* Check for null being passed in a pointer argument that must be 5758 non-null. We also need to do this if format checking is enabled. */ 5759 5760 if (warn_nonnull) 5761 check_function_nonnull (attrs, params); 5762 5763 /* Check for errors in format strings. */ 5764 5765 if (warn_format || warn_missing_format_attribute) 5766 check_function_format (attrs, params); 5767 5768 if (warn_format) 5769 check_function_sentinel (attrs, params, typelist); 5770} 5771 5772/* Generic argument checking recursion routine. PARAM is the argument to 5773 be checked. PARAM_NUM is the number of the argument. CALLBACK is invoked 5774 once the argument is resolved. CTX is context for the callback. */ 5775void 5776check_function_arguments_recurse (void (*callback) 5777 (void *, tree, unsigned HOST_WIDE_INT), 5778 void *ctx, tree param, 5779 unsigned HOST_WIDE_INT param_num) 5780{ 5781 if ((TREE_CODE (param) == NOP_EXPR || TREE_CODE (param) == CONVERT_EXPR) 5782 && (TYPE_PRECISION (TREE_TYPE (param)) 5783 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (param, 0))))) 5784 { 5785 /* Strip coercion. */ 5786 check_function_arguments_recurse (callback, ctx, 5787 TREE_OPERAND (param, 0), param_num); 5788 return; 5789 } 5790 5791 if (TREE_CODE (param) == CALL_EXPR) 5792 { 5793 tree type = TREE_TYPE (TREE_TYPE (TREE_OPERAND (param, 0))); 5794 tree attrs; 5795 bool found_format_arg = false; 5796 5797 /* See if this is a call to a known internationalization function 5798 that modifies a format arg. Such a function may have multiple 5799 format_arg attributes (for example, ngettext). */ 5800 5801 for (attrs = TYPE_ATTRIBUTES (type); 5802 attrs; 5803 attrs = TREE_CHAIN (attrs)) 5804 if (is_attribute_p ("format_arg", TREE_PURPOSE (attrs))) 5805 { 5806 tree inner_args; 5807 tree format_num_expr; 5808 int format_num; 5809 int i; 5810 5811 /* Extract the argument number, which was previously checked 5812 to be valid. */ 5813 format_num_expr = TREE_VALUE (TREE_VALUE (attrs)); 5814 5815 gcc_assert (TREE_CODE (format_num_expr) == INTEGER_CST 5816 && !TREE_INT_CST_HIGH (format_num_expr)); 5817 5818 format_num = TREE_INT_CST_LOW (format_num_expr); 5819 5820 for (inner_args = TREE_OPERAND (param, 1), i = 1; 5821 inner_args != 0; 5822 inner_args = TREE_CHAIN (inner_args), i++) 5823 if (i == format_num) 5824 { 5825 check_function_arguments_recurse (callback, ctx, 5826 TREE_VALUE (inner_args), 5827 param_num); 5828 found_format_arg = true; 5829 break; 5830 } 5831 } 5832 5833 /* If we found a format_arg attribute and did a recursive check, 5834 we are done with checking this argument. Otherwise, we continue 5835 and this will be considered a non-literal. */ 5836 if (found_format_arg) 5837 return; 5838 } 5839 5840 if (TREE_CODE (param) == COND_EXPR) 5841 { 5842 /* Check both halves of the conditional expression. */ 5843 check_function_arguments_recurse (callback, ctx, 5844 TREE_OPERAND (param, 1), param_num); 5845 check_function_arguments_recurse (callback, ctx, 5846 TREE_OPERAND (param, 2), param_num); 5847 return; 5848 } 5849 5850 (*callback) (ctx, param, param_num); 5851} 5852 5853/* Function to help qsort sort FIELD_DECLs by name order. */ 5854 5855int 5856field_decl_cmp (const void *x_p, const void *y_p) 5857{ 5858 const tree *const x = (const tree *const) x_p; 5859 const tree *const y = (const tree *const) y_p; 5860 5861 if (DECL_NAME (*x) == DECL_NAME (*y)) 5862 /* A nontype is "greater" than a type. */ 5863 return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL); 5864 if (DECL_NAME (*x) == NULL_TREE) 5865 return -1; 5866 if (DECL_NAME (*y) == NULL_TREE) 5867 return 1; 5868 if (DECL_NAME (*x) < DECL_NAME (*y)) 5869 return -1; 5870 return 1; 5871} 5872 5873static struct { 5874 gt_pointer_operator new_value; 5875 void *cookie; 5876} resort_data; 5877 5878/* This routine compares two fields like field_decl_cmp but using the 5879pointer operator in resort_data. */ 5880 5881static int 5882resort_field_decl_cmp (const void *x_p, const void *y_p) 5883{ 5884 const tree *const x = (const tree *const) x_p; 5885 const tree *const y = (const tree *const) y_p; 5886 5887 if (DECL_NAME (*x) == DECL_NAME (*y)) 5888 /* A nontype is "greater" than a type. */ 5889 return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL); 5890 if (DECL_NAME (*x) == NULL_TREE) 5891 return -1; 5892 if (DECL_NAME (*y) == NULL_TREE) 5893 return 1; 5894 { 5895 tree d1 = DECL_NAME (*x); 5896 tree d2 = DECL_NAME (*y); 5897 resort_data.new_value (&d1, resort_data.cookie); 5898 resort_data.new_value (&d2, resort_data.cookie); 5899 if (d1 < d2) 5900 return -1; 5901 } 5902 return 1; 5903} 5904 5905/* Resort DECL_SORTED_FIELDS because pointers have been reordered. */ 5906 5907void 5908resort_sorted_fields (void *obj, 5909 void * ARG_UNUSED (orig_obj), 5910 gt_pointer_operator new_value, 5911 void *cookie) 5912{ 5913 struct sorted_fields_type *sf = (struct sorted_fields_type *) obj; 5914 resort_data.new_value = new_value; 5915 resort_data.cookie = cookie; 5916 qsort (&sf->elts[0], sf->len, sizeof (tree), 5917 resort_field_decl_cmp); 5918} 5919 5920/* Subroutine of c_parse_error. 5921 Return the result of concatenating LHS and RHS. RHS is really 5922 a string literal, its first character is indicated by RHS_START and 5923 RHS_SIZE is its length (including the terminating NUL character). 5924 5925 The caller is responsible for deleting the returned pointer. */ 5926 5927static char * 5928catenate_strings (const char *lhs, const char *rhs_start, int rhs_size) 5929{ 5930 const int lhs_size = strlen (lhs); 5931 char *result = XNEWVEC (char, lhs_size + rhs_size); 5932 strncpy (result, lhs, lhs_size); 5933 strncpy (result + lhs_size, rhs_start, rhs_size); 5934 return result; 5935} 5936 5937/* Issue the error given by GMSGID, indicating that it occurred before 5938 TOKEN, which had the associated VALUE. */ 5939 5940void 5941c_parse_error (const char *gmsgid, enum cpp_ttype token, tree value) 5942{ 5943#define catenate_messages(M1, M2) catenate_strings ((M1), (M2), sizeof (M2)) 5944 5945 char *message = NULL; 5946 5947 if (token == CPP_EOF) 5948 message = catenate_messages (gmsgid, " at end of input"); 5949 else if (token == CPP_CHAR || token == CPP_WCHAR) 5950 { 5951 unsigned int val = TREE_INT_CST_LOW (value); 5952 const char *const ell = (token == CPP_CHAR) ? "" : "L"; 5953 if (val <= UCHAR_MAX && ISGRAPH (val)) 5954 message = catenate_messages (gmsgid, " before %s'%c'"); 5955 else 5956 message = catenate_messages (gmsgid, " before %s'\\x%x'"); 5957 5958 error (message, ell, val); 5959 free (message); 5960 message = NULL; 5961 } 5962 else if (token == CPP_STRING || token == CPP_WSTRING) 5963 message = catenate_messages (gmsgid, " before string constant"); 5964 else if (token == CPP_NUMBER) 5965 message = catenate_messages (gmsgid, " before numeric constant"); 5966 else if (token == CPP_NAME) 5967 { 5968 message = catenate_messages (gmsgid, " before %qE"); 5969 error (message, value); 5970 free (message); 5971 message = NULL; 5972 } 5973 else if (token == CPP_PRAGMA) 5974 message = catenate_messages (gmsgid, " before %<#pragma%>"); 5975 else if (token == CPP_PRAGMA_EOL) 5976 message = catenate_messages (gmsgid, " before end of line"); 5977 else if (token < N_TTYPES) 5978 { 5979 message = catenate_messages (gmsgid, " before %qs token"); 5980 error (message, cpp_type2name (token)); 5981 free (message); 5982 message = NULL; 5983 } 5984 else 5985 error (gmsgid); 5986 5987 if (message) 5988 { 5989 error (message); 5990 free (message); 5991 } 5992#undef catenate_messages 5993} 5994 5995/* Walk a gimplified function and warn for functions whose return value is 5996 ignored and attribute((warn_unused_result)) is set. This is done before 5997 inlining, so we don't have to worry about that. */ 5998 5999void 6000c_warn_unused_result (tree *top_p) 6001{ 6002 tree t = *top_p; 6003 tree_stmt_iterator i; 6004 tree fdecl, ftype; 6005 6006 switch (TREE_CODE (t)) 6007 { 6008 case STATEMENT_LIST: 6009 for (i = tsi_start (*top_p); !tsi_end_p (i); tsi_next (&i)) 6010 c_warn_unused_result (tsi_stmt_ptr (i)); 6011 break; 6012 6013 case COND_EXPR: 6014 c_warn_unused_result (&COND_EXPR_THEN (t)); 6015 c_warn_unused_result (&COND_EXPR_ELSE (t)); 6016 break; 6017 case BIND_EXPR: 6018 c_warn_unused_result (&BIND_EXPR_BODY (t)); 6019 break; 6020 case TRY_FINALLY_EXPR: 6021 case TRY_CATCH_EXPR: 6022 c_warn_unused_result (&TREE_OPERAND (t, 0)); 6023 c_warn_unused_result (&TREE_OPERAND (t, 1)); 6024 break; 6025 case CATCH_EXPR: 6026 c_warn_unused_result (&CATCH_BODY (t)); 6027 break; 6028 case EH_FILTER_EXPR: 6029 c_warn_unused_result (&EH_FILTER_FAILURE (t)); 6030 break; 6031 6032 case CALL_EXPR: 6033 if (TREE_USED (t)) 6034 break; 6035 6036 /* This is a naked call, as opposed to a CALL_EXPR nested inside 6037 a MODIFY_EXPR. All calls whose value is ignored should be 6038 represented like this. Look for the attribute. */ 6039 fdecl = get_callee_fndecl (t); 6040 if (fdecl) 6041 ftype = TREE_TYPE (fdecl); 6042 else 6043 { 6044 ftype = TREE_TYPE (TREE_OPERAND (t, 0)); 6045 /* Look past pointer-to-function to the function type itself. */ 6046 ftype = TREE_TYPE (ftype); 6047 } 6048 6049 if (lookup_attribute ("warn_unused_result", TYPE_ATTRIBUTES (ftype))) 6050 { 6051 if (fdecl) 6052 warning (0, "%Hignoring return value of %qD, " 6053 "declared with attribute warn_unused_result", 6054 EXPR_LOCUS (t), fdecl); 6055 else 6056 warning (0, "%Hignoring return value of function " 6057 "declared with attribute warn_unused_result", 6058 EXPR_LOCUS (t)); 6059 } 6060 break; 6061 6062 default: 6063 /* Not a container, not a call, or a call whose value is used. */ 6064 break; 6065 } 6066} 6067 6068/* Convert a character from the host to the target execution character 6069 set. cpplib handles this, mostly. */ 6070 6071HOST_WIDE_INT 6072c_common_to_target_charset (HOST_WIDE_INT c) 6073{ 6074 /* Character constants in GCC proper are sign-extended under -fsigned-char, 6075 zero-extended under -fno-signed-char. cpplib insists that characters 6076 and character constants are always unsigned. Hence we must convert 6077 back and forth. */ 6078 cppchar_t uc = ((cppchar_t)c) & ((((cppchar_t)1) << CHAR_BIT)-1); 6079 6080 uc = cpp_host_to_exec_charset (parse_in, uc); 6081 6082 if (flag_signed_char) 6083 return ((HOST_WIDE_INT)uc) << (HOST_BITS_PER_WIDE_INT - CHAR_TYPE_SIZE) 6084 >> (HOST_BITS_PER_WIDE_INT - CHAR_TYPE_SIZE); 6085 else 6086 return uc; 6087} 6088 6089/* Build the result of __builtin_offsetof. EXPR is a nested sequence of 6090 component references, with STOP_REF, or alternatively an INDIRECT_REF of 6091 NULL, at the bottom; much like the traditional rendering of offsetof as a 6092 macro. Returns the folded and properly cast result. */ 6093 6094static tree 6095fold_offsetof_1 (tree expr, tree stop_ref) 6096{ 6097 enum tree_code code = PLUS_EXPR; 6098 tree base, off, t; 6099 6100 if (expr == stop_ref && TREE_CODE (expr) != ERROR_MARK) 6101 return size_zero_node; 6102 6103 switch (TREE_CODE (expr)) 6104 { 6105 case ERROR_MARK: 6106 return expr; 6107 6108 case VAR_DECL: 6109 error ("cannot apply %<offsetof%> to static data member %qD", expr); 6110 return error_mark_node; 6111 6112 case CALL_EXPR: 6113 error ("cannot apply %<offsetof%> when %<operator[]%> is overloaded"); 6114 return error_mark_node; 6115 6116 case INTEGER_CST: 6117 gcc_assert (integer_zerop (expr)); 6118 return size_zero_node; 6119 6120 case NOP_EXPR: 6121 case INDIRECT_REF: 6122 base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref); 6123 gcc_assert (base == error_mark_node || base == size_zero_node); 6124 return base; 6125 6126 case COMPONENT_REF: 6127 base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref); 6128 if (base == error_mark_node) 6129 return base; 6130 6131 t = TREE_OPERAND (expr, 1); 6132 if (DECL_C_BIT_FIELD (t)) 6133 { 6134 error ("attempt to take address of bit-field structure " 6135 "member %qD", t); 6136 return error_mark_node; 6137 } 6138 off = size_binop (PLUS_EXPR, DECL_FIELD_OFFSET (t), 6139 size_int (tree_low_cst (DECL_FIELD_BIT_OFFSET (t), 1) 6140 / BITS_PER_UNIT)); 6141 break; 6142 6143 case ARRAY_REF: 6144 base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref); 6145 if (base == error_mark_node) 6146 return base; 6147 6148 t = TREE_OPERAND (expr, 1); 6149 if (TREE_CODE (t) == INTEGER_CST && tree_int_cst_sgn (t) < 0) 6150 { 6151 code = MINUS_EXPR; 6152 t = fold_build1 (NEGATE_EXPR, TREE_TYPE (t), t); 6153 } 6154 t = convert (sizetype, t); 6155 off = size_binop (MULT_EXPR, TYPE_SIZE_UNIT (TREE_TYPE (expr)), t); 6156 break; 6157 6158 case COMPOUND_EXPR: 6159 /* Handle static members of volatile structs. */ 6160 t = TREE_OPERAND (expr, 1); 6161 gcc_assert (TREE_CODE (t) == VAR_DECL); 6162 return fold_offsetof_1 (t, stop_ref); 6163 6164 default: 6165 gcc_unreachable (); 6166 } 6167 6168 return size_binop (code, base, off); 6169} 6170 6171tree 6172fold_offsetof (tree expr, tree stop_ref) 6173{ 6174 /* Convert back from the internal sizetype to size_t. */ 6175 return convert (size_type_node, fold_offsetof_1 (expr, stop_ref)); 6176} 6177 6178/* Print an error message for an invalid lvalue. USE says 6179 how the lvalue is being used and so selects the error message. */ 6180 6181void 6182lvalue_error (enum lvalue_use use) 6183{ 6184 switch (use) 6185 { 6186 case lv_assign: 6187 error ("lvalue required as left operand of assignment"); 6188 break; 6189 case lv_increment: 6190 error ("lvalue required as increment operand"); 6191 break; 6192 case lv_decrement: 6193 error ("lvalue required as decrement operand"); 6194 break; 6195 case lv_addressof: 6196 error ("lvalue required as unary %<&%> operand"); 6197 break; 6198 case lv_asm: 6199 error ("lvalue required in asm statement"); 6200 break; 6201 default: 6202 gcc_unreachable (); 6203 } 6204} 6205 6206/* *PTYPE is an incomplete array. Complete it with a domain based on 6207 INITIAL_VALUE. If INITIAL_VALUE is not present, use 1 if DO_DEFAULT 6208 is true. Return 0 if successful, 1 if INITIAL_VALUE can't be deciphered, 6209 2 if INITIAL_VALUE was NULL, and 3 if INITIAL_VALUE was empty. */ 6210 6211int 6212complete_array_type (tree *ptype, tree initial_value, bool do_default) 6213{ 6214 tree maxindex, type, main_type, elt, unqual_elt; 6215 int failure = 0, quals; 6216 6217 maxindex = size_zero_node; 6218 if (initial_value) 6219 { 6220 if (TREE_CODE (initial_value) == STRING_CST) 6221 { 6222 int eltsize 6223 = int_size_in_bytes (TREE_TYPE (TREE_TYPE (initial_value))); 6224 maxindex = size_int (TREE_STRING_LENGTH (initial_value)/eltsize - 1); 6225 } 6226 else if (TREE_CODE (initial_value) == CONSTRUCTOR) 6227 { 6228 VEC(constructor_elt,gc) *v = CONSTRUCTOR_ELTS (initial_value); 6229 6230 if (VEC_empty (constructor_elt, v)) 6231 { 6232 if (pedantic) 6233 failure = 3; 6234 maxindex = integer_minus_one_node; 6235 } 6236 else 6237 { 6238 tree curindex; 6239 unsigned HOST_WIDE_INT cnt; 6240 constructor_elt *ce; 6241 6242 if (VEC_index (constructor_elt, v, 0)->index) 6243 maxindex = fold_convert (sizetype, 6244 VEC_index (constructor_elt, 6245 v, 0)->index); 6246 curindex = maxindex; 6247 6248 for (cnt = 1; 6249 VEC_iterate (constructor_elt, v, cnt, ce); 6250 cnt++) 6251 { 6252 if (ce->index) 6253 curindex = fold_convert (sizetype, ce->index); 6254 else 6255 curindex = size_binop (PLUS_EXPR, curindex, size_one_node); 6256 6257 if (tree_int_cst_lt (maxindex, curindex)) 6258 maxindex = curindex; 6259 } 6260 } 6261 } 6262 else 6263 { 6264 /* Make an error message unless that happened already. */ 6265 if (initial_value != error_mark_node) 6266 failure = 1; 6267 } 6268 } 6269 else 6270 { 6271 failure = 2; 6272 if (!do_default) 6273 return failure; 6274 } 6275 6276 type = *ptype; 6277 elt = TREE_TYPE (type); 6278 quals = TYPE_QUALS (strip_array_types (elt)); 6279 if (quals == 0) 6280 unqual_elt = elt; 6281 else 6282 unqual_elt = c_build_qualified_type (elt, TYPE_UNQUALIFIED); 6283 6284 /* Using build_distinct_type_copy and modifying things afterward instead 6285 of using build_array_type to create a new type preserves all of the 6286 TYPE_LANG_FLAG_? bits that the front end may have set. */ 6287 main_type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type)); 6288 TREE_TYPE (main_type) = unqual_elt; 6289 TYPE_DOMAIN (main_type) = build_index_type (maxindex); 6290 layout_type (main_type); 6291 6292 if (quals == 0) 6293 type = main_type; 6294 else 6295 type = c_build_qualified_type (main_type, quals); 6296 6297 *ptype = type; 6298 return failure; 6299} 6300 6301 6302/* Used to help initialize the builtin-types.def table. When a type of 6303 the correct size doesn't exist, use error_mark_node instead of NULL. 6304 The later results in segfaults even when a decl using the type doesn't 6305 get invoked. */ 6306 6307tree 6308builtin_type_for_size (int size, bool unsignedp) 6309{ 6310 tree type = lang_hooks.types.type_for_size (size, unsignedp); 6311 return type ? type : error_mark_node; 6312} 6313 6314/* A helper function for resolve_overloaded_builtin in resolving the 6315 overloaded __sync_ builtins. Returns a positive power of 2 if the 6316 first operand of PARAMS is a pointer to a supported data type. 6317 Returns 0 if an error is encountered. */ 6318 6319static int 6320sync_resolve_size (tree function, tree params) 6321{ 6322 tree type; 6323 int size; 6324 6325 if (params == NULL) 6326 { 6327 error ("too few arguments to function %qE", function); 6328 return 0; 6329 } 6330 6331 type = TREE_TYPE (TREE_VALUE (params)); 6332 if (TREE_CODE (type) != POINTER_TYPE) 6333 goto incompatible; 6334 6335 type = TREE_TYPE (type); 6336 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type)) 6337 goto incompatible; 6338 6339 size = tree_low_cst (TYPE_SIZE_UNIT (type), 1); 6340 if (size == 1 || size == 2 || size == 4 || size == 8 || size == 16) 6341 return size; 6342 6343 incompatible: 6344 error ("incompatible type for argument %d of %qE", 1, function); 6345 return 0; 6346} 6347 6348/* A helper function for resolve_overloaded_builtin. Adds casts to 6349 PARAMS to make arguments match up with those of FUNCTION. Drops 6350 the variadic arguments at the end. Returns false if some error 6351 was encountered; true on success. */ 6352 6353static bool 6354sync_resolve_params (tree orig_function, tree function, tree params) 6355{ 6356 tree arg_types = TYPE_ARG_TYPES (TREE_TYPE (function)); 6357 tree ptype; 6358 int number; 6359 6360 /* We've declared the implementation functions to use "volatile void *" 6361 as the pointer parameter, so we shouldn't get any complaints from the 6362 call to check_function_arguments what ever type the user used. */ 6363 arg_types = TREE_CHAIN (arg_types); 6364 ptype = TREE_TYPE (TREE_TYPE (TREE_VALUE (params))); 6365 number = 2; 6366 6367 /* For the rest of the values, we need to cast these to FTYPE, so that we 6368 don't get warnings for passing pointer types, etc. */ 6369 while (arg_types != void_list_node) 6370 { 6371 tree val; 6372 6373 params = TREE_CHAIN (params); 6374 if (params == NULL) 6375 { 6376 error ("too few arguments to function %qE", orig_function); 6377 return false; 6378 } 6379 6380 /* ??? Ideally for the first conversion we'd use convert_for_assignment 6381 so that we get warnings for anything that doesn't match the pointer 6382 type. This isn't portable across the C and C++ front ends atm. */ 6383 val = TREE_VALUE (params); 6384 val = convert (ptype, val); 6385 val = convert (TREE_VALUE (arg_types), val); 6386 TREE_VALUE (params) = val; 6387 6388 arg_types = TREE_CHAIN (arg_types); 6389 number++; 6390 } 6391 6392 /* The definition of these primitives is variadic, with the remaining 6393 being "an optional list of variables protected by the memory barrier". 6394 No clue what that's supposed to mean, precisely, but we consider all 6395 call-clobbered variables to be protected so we're safe. */ 6396 TREE_CHAIN (params) = NULL; 6397 6398 return true; 6399} 6400 6401/* A helper function for resolve_overloaded_builtin. Adds a cast to 6402 RESULT to make it match the type of the first pointer argument in 6403 PARAMS. */ 6404 6405static tree 6406sync_resolve_return (tree params, tree result) 6407{ 6408 tree ptype = TREE_TYPE (TREE_TYPE (TREE_VALUE (params))); 6409 ptype = TYPE_MAIN_VARIANT (ptype); 6410 return convert (ptype, result); 6411} 6412 6413/* Some builtin functions are placeholders for other expressions. This 6414 function should be called immediately after parsing the call expression 6415 before surrounding code has committed to the type of the expression. 6416 6417 FUNCTION is the DECL that has been invoked; it is known to be a builtin. 6418 PARAMS is the argument list for the call. The return value is non-null 6419 when expansion is complete, and null if normal processing should 6420 continue. */ 6421 6422tree 6423resolve_overloaded_builtin (tree function, tree params) 6424{ 6425 enum built_in_function orig_code = DECL_FUNCTION_CODE (function); 6426 switch (DECL_BUILT_IN_CLASS (function)) 6427 { 6428 case BUILT_IN_NORMAL: 6429 break; 6430 case BUILT_IN_MD: 6431 if (targetm.resolve_overloaded_builtin) 6432 return targetm.resolve_overloaded_builtin (function, params); 6433 else 6434 return NULL_TREE; 6435 default: 6436 return NULL_TREE; 6437 } 6438 6439 /* Handle BUILT_IN_NORMAL here. */ 6440 switch (orig_code) 6441 { 6442 case BUILT_IN_FETCH_AND_ADD_N: 6443 case BUILT_IN_FETCH_AND_SUB_N: 6444 case BUILT_IN_FETCH_AND_OR_N: 6445 case BUILT_IN_FETCH_AND_AND_N: 6446 case BUILT_IN_FETCH_AND_XOR_N: 6447 case BUILT_IN_FETCH_AND_NAND_N: 6448 case BUILT_IN_ADD_AND_FETCH_N: 6449 case BUILT_IN_SUB_AND_FETCH_N: 6450 case BUILT_IN_OR_AND_FETCH_N: 6451 case BUILT_IN_AND_AND_FETCH_N: 6452 case BUILT_IN_XOR_AND_FETCH_N: 6453 case BUILT_IN_NAND_AND_FETCH_N: 6454 case BUILT_IN_BOOL_COMPARE_AND_SWAP_N: 6455 case BUILT_IN_VAL_COMPARE_AND_SWAP_N: 6456 case BUILT_IN_LOCK_TEST_AND_SET_N: 6457 case BUILT_IN_LOCK_RELEASE_N: 6458 { 6459 int n = sync_resolve_size (function, params); 6460 tree new_function, result; 6461 6462 if (n == 0) 6463 return error_mark_node; 6464 6465 new_function = built_in_decls[orig_code + exact_log2 (n) + 1]; 6466 if (!sync_resolve_params (function, new_function, params)) 6467 return error_mark_node; 6468 6469 result = build_function_call (new_function, params); 6470 if (orig_code != BUILT_IN_BOOL_COMPARE_AND_SWAP_N 6471 && orig_code != BUILT_IN_LOCK_RELEASE_N) 6472 result = sync_resolve_return (params, result); 6473 6474 return result; 6475 } 6476 6477 default: 6478 return NULL_TREE; 6479 } 6480} 6481 6482/* Ignoring their sign, return true if two scalar types are the same. */ 6483bool 6484same_scalar_type_ignoring_signedness (tree t1, tree t2) 6485{ 6486 enum tree_code c1 = TREE_CODE (t1), c2 = TREE_CODE (t2); 6487 6488 gcc_assert ((c1 == INTEGER_TYPE || c1 == REAL_TYPE) 6489 && (c2 == INTEGER_TYPE || c2 == REAL_TYPE)); 6490 6491 /* Equality works here because c_common_signed_type uses 6492 TYPE_MAIN_VARIANT. */ 6493 return lang_hooks.types.signed_type (t1) 6494 == lang_hooks.types.signed_type (t2); 6495} 6496 6497/* Check for missing format attributes on function pointers. LTYPE is 6498 the new type or left-hand side type. RTYPE is the old type or 6499 right-hand side type. Returns TRUE if LTYPE is missing the desired 6500 attribute. */ 6501 6502bool 6503check_missing_format_attribute (tree ltype, tree rtype) 6504{ 6505 tree const ttr = TREE_TYPE (rtype), ttl = TREE_TYPE (ltype); 6506 tree ra; 6507 6508 for (ra = TYPE_ATTRIBUTES (ttr); ra; ra = TREE_CHAIN (ra)) 6509 if (is_attribute_p ("format", TREE_PURPOSE (ra))) 6510 break; 6511 if (ra) 6512 { 6513 tree la; 6514 for (la = TYPE_ATTRIBUTES (ttl); la; la = TREE_CHAIN (la)) 6515 if (is_attribute_p ("format", TREE_PURPOSE (la))) 6516 break; 6517 return !la; 6518 } 6519 else 6520 return false; 6521} 6522 6523/* Subscripting with type char is likely to lose on a machine where 6524 chars are signed. So warn on any machine, but optionally. Don't 6525 warn for unsigned char since that type is safe. Don't warn for 6526 signed char because anyone who uses that must have done so 6527 deliberately. Furthermore, we reduce the false positive load by 6528 warning only for non-constant value of type char. */ 6529 6530void 6531warn_array_subscript_with_type_char (tree index) 6532{ 6533 if (TYPE_MAIN_VARIANT (TREE_TYPE (index)) == char_type_node 6534 && TREE_CODE (index) != INTEGER_CST) 6535 warning (OPT_Wchar_subscripts, "array subscript has type %<char%>"); 6536} 6537 6538/* Implement -Wparentheses for the unexpected C precedence rules, to 6539 cover cases like x + y << z which readers are likely to 6540 misinterpret. We have seen an expression in which CODE is a binary 6541 operator used to combine expressions headed by CODE_LEFT and 6542 CODE_RIGHT. CODE_LEFT and CODE_RIGHT may be ERROR_MARK, which 6543 means that that side of the expression was not formed using a 6544 binary operator, or it was enclosed in parentheses. */ 6545 6546void 6547warn_about_parentheses (enum tree_code code, enum tree_code code_left, 6548 enum tree_code code_right) 6549{ 6550 if (!warn_parentheses) 6551 return; 6552 6553 if (code == LSHIFT_EXPR || code == RSHIFT_EXPR) 6554 { 6555 if (code_left == PLUS_EXPR || code_left == MINUS_EXPR 6556 || code_right == PLUS_EXPR || code_right == MINUS_EXPR) 6557 warning (OPT_Wparentheses, 6558 "suggest parentheses around + or - inside shift"); 6559 } 6560 6561 if (code == TRUTH_ORIF_EXPR) 6562 { 6563 if (code_left == TRUTH_ANDIF_EXPR 6564 || code_right == TRUTH_ANDIF_EXPR) 6565 warning (OPT_Wparentheses, 6566 "suggest parentheses around && within ||"); 6567 } 6568 6569 if (code == BIT_IOR_EXPR) 6570 { 6571 if (code_left == BIT_AND_EXPR || code_left == BIT_XOR_EXPR 6572 || code_left == PLUS_EXPR || code_left == MINUS_EXPR 6573 || code_right == BIT_AND_EXPR || code_right == BIT_XOR_EXPR 6574 || code_right == PLUS_EXPR || code_right == MINUS_EXPR) 6575 warning (OPT_Wparentheses, 6576 "suggest parentheses around arithmetic in operand of |"); 6577 /* Check cases like x|y==z */ 6578 if (TREE_CODE_CLASS (code_left) == tcc_comparison 6579 || TREE_CODE_CLASS (code_right) == tcc_comparison) 6580 warning (OPT_Wparentheses, 6581 "suggest parentheses around comparison in operand of |"); 6582 } 6583 6584 if (code == BIT_XOR_EXPR) 6585 { 6586 if (code_left == BIT_AND_EXPR 6587 || code_left == PLUS_EXPR || code_left == MINUS_EXPR 6588 || code_right == BIT_AND_EXPR 6589 || code_right == PLUS_EXPR || code_right == MINUS_EXPR) 6590 warning (OPT_Wparentheses, 6591 "suggest parentheses around arithmetic in operand of ^"); 6592 /* Check cases like x^y==z */ 6593 if (TREE_CODE_CLASS (code_left) == tcc_comparison 6594 || TREE_CODE_CLASS (code_right) == tcc_comparison) 6595 warning (OPT_Wparentheses, 6596 "suggest parentheses around comparison in operand of ^"); 6597 } 6598 6599 if (code == BIT_AND_EXPR) 6600 { 6601 if (code_left == PLUS_EXPR || code_left == MINUS_EXPR 6602 || code_right == PLUS_EXPR || code_right == MINUS_EXPR) 6603 warning (OPT_Wparentheses, 6604 "suggest parentheses around + or - in operand of &"); 6605 /* Check cases like x&y==z */ 6606 if (TREE_CODE_CLASS (code_left) == tcc_comparison 6607 || TREE_CODE_CLASS (code_right) == tcc_comparison) 6608 warning (OPT_Wparentheses, 6609 "suggest parentheses around comparison in operand of &"); 6610 } 6611 6612 /* Similarly, check for cases like 1<=i<=10 that are probably errors. */ 6613 if (TREE_CODE_CLASS (code) == tcc_comparison 6614 && (TREE_CODE_CLASS (code_left) == tcc_comparison 6615 || TREE_CODE_CLASS (code_right) == tcc_comparison)) 6616 warning (OPT_Wparentheses, "comparisons like X<=Y<=Z do not " 6617 "have their mathematical meaning"); 6618} 6619 6620 6621#include "gt-c-common.h" 6622