c-common.c revision 259405
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. 920 Invoke this function on every expression that 921 (1) appears in the source code, and 922 (2) might be a constant expression that overflowed, and 923 (3) is not already checked by convert_and_check; 924 however, do not invoke this function on operands of explicit casts. */ 925 926void 927overflow_warning (tree value) 928{ 929 if ((TREE_CODE (value) == INTEGER_CST 930 || (TREE_CODE (value) == COMPLEX_CST 931 && TREE_CODE (TREE_REALPART (value)) == INTEGER_CST)) 932 && TREE_OVERFLOW (value)) 933 { 934 TREE_OVERFLOW (value) = 0; 935 if (skip_evaluation == 0) 936 warning (OPT_Woverflow, "integer overflow in expression"); 937 } 938 else if ((TREE_CODE (value) == REAL_CST 939 || (TREE_CODE (value) == COMPLEX_CST 940 && TREE_CODE (TREE_REALPART (value)) == REAL_CST)) 941 && TREE_OVERFLOW (value)) 942 { 943 TREE_OVERFLOW (value) = 0; 944 if (skip_evaluation == 0) 945 warning (OPT_Woverflow, "floating point overflow in expression"); 946 } 947 else if (TREE_CODE (value) == VECTOR_CST && TREE_OVERFLOW (value)) 948 { 949 TREE_OVERFLOW (value) = 0; 950 if (skip_evaluation == 0) 951 warning (OPT_Woverflow, "vector overflow in expression"); 952 } 953} 954 955/* Print a warning if a large constant is truncated to unsigned, 956 or if -Wconversion is used and a constant < 0 is converted to unsigned. 957 Invoke this function on every expression that might be implicitly 958 converted to an unsigned type. */ 959 960static void 961unsigned_conversion_warning (tree result, tree operand) 962{ 963 tree type = TREE_TYPE (result); 964 965 if (TREE_CODE (operand) == INTEGER_CST 966 && TREE_CODE (type) == INTEGER_TYPE 967 && TYPE_UNSIGNED (type) 968 && skip_evaluation == 0 969 && !int_fits_type_p (operand, type)) 970 { 971 if (!int_fits_type_p (operand, c_common_signed_type (type))) 972 /* This detects cases like converting -129 or 256 to unsigned char. */ 973 warning (OPT_Woverflow, 974 "large integer implicitly truncated to unsigned type"); 975 else 976 warning (OPT_Wconversion, 977 "negative integer implicitly converted to unsigned type"); 978 } 979} 980 981/* Print a warning about casts that might indicate violation 982 of strict aliasing rules if -Wstrict-aliasing is used and 983 strict aliasing mode is in effect. OTYPE is the original 984 TREE_TYPE of EXPR, and TYPE the type we're casting to. */ 985 986bool 987strict_aliasing_warning (tree otype, tree type, tree expr) 988{ 989 if (!(flag_strict_aliasing && POINTER_TYPE_P (type) 990 && POINTER_TYPE_P (otype) && !VOID_TYPE_P (TREE_TYPE (type)))) 991 return false; 992 993 if ((warn_strict_aliasing > 1) && TREE_CODE (expr) == ADDR_EXPR 994 && (DECL_P (TREE_OPERAND (expr, 0)) 995 || handled_component_p (TREE_OPERAND (expr, 0)))) 996 { 997 /* Casting the address of an object to non void pointer. Warn 998 if the cast breaks type based aliasing. */ 999 if (!COMPLETE_TYPE_P (TREE_TYPE (type)) && warn_strict_aliasing == 2) 1000 { 1001 warning (OPT_Wstrict_aliasing, "type-punning to incomplete type " 1002 "might break strict-aliasing rules"); 1003 return true; 1004 } 1005 else 1006 { 1007 /* warn_strict_aliasing >= 3. This includes the default (3). 1008 Only warn if the cast is dereferenced immediately. */ 1009 HOST_WIDE_INT set1 = 1010 get_alias_set (TREE_TYPE (TREE_OPERAND (expr, 0))); 1011 HOST_WIDE_INT set2 = get_alias_set (TREE_TYPE (type)); 1012 1013 if (!alias_sets_conflict_p (set1, set2)) 1014 { 1015 warning (OPT_Wstrict_aliasing, "dereferencing type-punned " 1016 "pointer will break strict-aliasing rules"); 1017 return true; 1018 } 1019 else if (warn_strict_aliasing == 2 1020 && !alias_sets_might_conflict_p (set1, set2)) 1021 { 1022 warning (OPT_Wstrict_aliasing, "dereferencing type-punned " 1023 "pointer might break strict-aliasing rules"); 1024 return true; 1025 } 1026 } 1027 } 1028 else 1029 if ((warn_strict_aliasing == 1) && !VOID_TYPE_P (TREE_TYPE (otype))) 1030 { 1031 /* At this level, warn for any conversions, even if an address is 1032 not taken in the same statement. This will likely produce many 1033 false positives, but could be useful to pinpoint problems that 1034 are not revealed at higher levels. */ 1035 HOST_WIDE_INT set1 = get_alias_set (TREE_TYPE (otype)); 1036 HOST_WIDE_INT set2 = get_alias_set (TREE_TYPE (type)); 1037 if (!COMPLETE_TYPE_P(type) 1038 || !alias_sets_might_conflict_p (set1, set2)) 1039 { 1040 warning (OPT_Wstrict_aliasing, "dereferencing type-punned " 1041 "pointer might break strict-aliasing rules"); 1042 return true; 1043 } 1044 } 1045 1046 return false; 1047} 1048 1049 1050/* Print a warning about if (); or if () .. else; constructs 1051 via the special empty statement node that we create. INNER_THEN 1052 and INNER_ELSE are the statement lists of the if and the else 1053 block. */ 1054 1055void 1056empty_body_warning (tree inner_then, tree inner_else) 1057{ 1058 if (extra_warnings) 1059 { 1060 if (TREE_CODE (inner_then) == STATEMENT_LIST 1061 && STATEMENT_LIST_TAIL (inner_then)) 1062 inner_then = STATEMENT_LIST_TAIL (inner_then)->stmt; 1063 1064 if (inner_else && TREE_CODE (inner_else) == STATEMENT_LIST 1065 && STATEMENT_LIST_TAIL (inner_else)) 1066 inner_else = STATEMENT_LIST_TAIL (inner_else)->stmt; 1067 1068 if (IS_EMPTY_STMT (inner_then) && !inner_else) 1069 warning (OPT_Wextra, "%Hempty body in an if-statement", 1070 EXPR_LOCUS (inner_then)); 1071 1072 if (inner_else && IS_EMPTY_STMT (inner_else)) 1073 warning (OPT_Wextra, "%Hempty body in an else-statement", 1074 EXPR_LOCUS (inner_else)); 1075 } 1076} 1077 1078 1079/* Nonzero if constant C has a value that is permissible 1080 for type TYPE (an INTEGER_TYPE). */ 1081 1082static int 1083constant_fits_type_p (tree c, tree type) 1084{ 1085 if (TREE_CODE (c) == INTEGER_CST) 1086 return int_fits_type_p (c, type); 1087 1088 c = convert (type, c); 1089 return !TREE_OVERFLOW (c); 1090} 1091 1092/* Nonzero if vector types T1 and T2 can be converted to each other 1093 without an explicit cast. */ 1094int 1095vector_types_convertible_p (tree t1, tree t2) 1096{ 1097 return targetm.vector_opaque_p (t1) 1098 || targetm.vector_opaque_p (t2) 1099 || (tree_int_cst_equal (TYPE_SIZE (t1), TYPE_SIZE (t2)) 1100 && (TREE_CODE (TREE_TYPE (t1)) != REAL_TYPE || 1101 TYPE_PRECISION (t1) == TYPE_PRECISION (t2)) 1102 && INTEGRAL_TYPE_P (TREE_TYPE (t1)) 1103 == INTEGRAL_TYPE_P (TREE_TYPE (t2))); 1104} 1105 1106/* Convert EXPR to TYPE, warning about conversion problems with constants. 1107 Invoke this function on every expression that is converted implicitly, 1108 i.e. because of language rules and not because of an explicit cast. */ 1109 1110tree 1111convert_and_check (tree type, tree expr) 1112{ 1113 tree t = convert (type, expr); 1114 if (TREE_CODE (t) == INTEGER_CST) 1115 { 1116 if (TREE_OVERFLOW (t)) 1117 { 1118 TREE_OVERFLOW (t) = 0; 1119 1120 /* Do not diagnose overflow in a constant expression merely 1121 because a conversion overflowed. */ 1122 TREE_CONSTANT_OVERFLOW (t) = CONSTANT_CLASS_P (expr) 1123 && TREE_CONSTANT_OVERFLOW (expr); 1124 1125 /* No warning for converting 0x80000000 to int. */ 1126 if (!(TYPE_UNSIGNED (type) < TYPE_UNSIGNED (TREE_TYPE (expr)) 1127 && TREE_CODE (TREE_TYPE (expr)) == INTEGER_TYPE 1128 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (expr)))) 1129 /* If EXPR fits in the unsigned version of TYPE, 1130 don't warn unless pedantic. */ 1131 if ((pedantic 1132 || TYPE_UNSIGNED (type) 1133 || !constant_fits_type_p (expr, 1134 c_common_unsigned_type (type))) 1135 && skip_evaluation == 0) 1136 warning (OPT_Woverflow, 1137 "overflow in implicit constant conversion"); 1138 } 1139 else 1140 unsigned_conversion_warning (t, expr); 1141 } 1142 return t; 1143} 1144 1145/* A node in a list that describes references to variables (EXPR), which are 1146 either read accesses if WRITER is zero, or write accesses, in which case 1147 WRITER is the parent of EXPR. */ 1148struct tlist 1149{ 1150 struct tlist *next; 1151 tree expr, writer; 1152}; 1153 1154/* Used to implement a cache the results of a call to verify_tree. We only 1155 use this for SAVE_EXPRs. */ 1156struct tlist_cache 1157{ 1158 struct tlist_cache *next; 1159 struct tlist *cache_before_sp; 1160 struct tlist *cache_after_sp; 1161 tree expr; 1162}; 1163 1164/* Obstack to use when allocating tlist structures, and corresponding 1165 firstobj. */ 1166static struct obstack tlist_obstack; 1167static char *tlist_firstobj = 0; 1168 1169/* Keep track of the identifiers we've warned about, so we can avoid duplicate 1170 warnings. */ 1171static struct tlist *warned_ids; 1172/* SAVE_EXPRs need special treatment. We process them only once and then 1173 cache the results. */ 1174static struct tlist_cache *save_expr_cache; 1175 1176static void add_tlist (struct tlist **, struct tlist *, tree, int); 1177static void merge_tlist (struct tlist **, struct tlist *, int); 1178static void verify_tree (tree, struct tlist **, struct tlist **, tree); 1179static int warning_candidate_p (tree); 1180static void warn_for_collisions (struct tlist *); 1181static void warn_for_collisions_1 (tree, tree, struct tlist *, int); 1182static struct tlist *new_tlist (struct tlist *, tree, tree); 1183 1184/* Create a new struct tlist and fill in its fields. */ 1185static struct tlist * 1186new_tlist (struct tlist *next, tree t, tree writer) 1187{ 1188 struct tlist *l; 1189 l = XOBNEW (&tlist_obstack, struct tlist); 1190 l->next = next; 1191 l->expr = t; 1192 l->writer = writer; 1193 return l; 1194} 1195 1196/* Add duplicates of the nodes found in ADD to the list *TO. If EXCLUDE_WRITER 1197 is nonnull, we ignore any node we find which has a writer equal to it. */ 1198 1199static void 1200add_tlist (struct tlist **to, struct tlist *add, tree exclude_writer, int copy) 1201{ 1202 while (add) 1203 { 1204 struct tlist *next = add->next; 1205 if (!copy) 1206 add->next = *to; 1207 if (!exclude_writer || add->writer != exclude_writer) 1208 *to = copy ? new_tlist (*to, add->expr, add->writer) : add; 1209 add = next; 1210 } 1211} 1212 1213/* Merge the nodes of ADD into TO. This merging process is done so that for 1214 each variable that already exists in TO, no new node is added; however if 1215 there is a write access recorded in ADD, and an occurrence on TO is only 1216 a read access, then the occurrence in TO will be modified to record the 1217 write. */ 1218 1219static void 1220merge_tlist (struct tlist **to, struct tlist *add, int copy) 1221{ 1222 struct tlist **end = to; 1223 1224 while (*end) 1225 end = &(*end)->next; 1226 1227 while (add) 1228 { 1229 int found = 0; 1230 struct tlist *tmp2; 1231 struct tlist *next = add->next; 1232 1233 for (tmp2 = *to; tmp2; tmp2 = tmp2->next) 1234 if (tmp2->expr == add->expr) 1235 { 1236 found = 1; 1237 if (!tmp2->writer) 1238 tmp2->writer = add->writer; 1239 } 1240 if (!found) 1241 { 1242 *end = copy ? add : new_tlist (NULL, add->expr, add->writer); 1243 end = &(*end)->next; 1244 *end = 0; 1245 } 1246 add = next; 1247 } 1248} 1249 1250/* WRITTEN is a variable, WRITER is its parent. Warn if any of the variable 1251 references in list LIST conflict with it, excluding reads if ONLY writers 1252 is nonzero. */ 1253 1254static void 1255warn_for_collisions_1 (tree written, tree writer, struct tlist *list, 1256 int only_writes) 1257{ 1258 struct tlist *tmp; 1259 1260 /* Avoid duplicate warnings. */ 1261 for (tmp = warned_ids; tmp; tmp = tmp->next) 1262 if (tmp->expr == written) 1263 return; 1264 1265 while (list) 1266 { 1267 if (list->expr == written 1268 && list->writer != writer 1269 && (!only_writes || list->writer) 1270 && DECL_NAME (list->expr)) 1271 { 1272 warned_ids = new_tlist (warned_ids, written, NULL_TREE); 1273 warning (0, "operation on %qE may be undefined", list->expr); 1274 } 1275 list = list->next; 1276 } 1277} 1278 1279/* Given a list LIST of references to variables, find whether any of these 1280 can cause conflicts due to missing sequence points. */ 1281 1282static void 1283warn_for_collisions (struct tlist *list) 1284{ 1285 struct tlist *tmp; 1286 1287 for (tmp = list; tmp; tmp = tmp->next) 1288 { 1289 if (tmp->writer) 1290 warn_for_collisions_1 (tmp->expr, tmp->writer, list, 0); 1291 } 1292} 1293 1294/* Return nonzero if X is a tree that can be verified by the sequence point 1295 warnings. */ 1296static int 1297warning_candidate_p (tree x) 1298{ 1299 return TREE_CODE (x) == VAR_DECL || TREE_CODE (x) == PARM_DECL; 1300} 1301 1302/* Walk the tree X, and record accesses to variables. If X is written by the 1303 parent tree, WRITER is the parent. 1304 We store accesses in one of the two lists: PBEFORE_SP, and PNO_SP. If this 1305 expression or its only operand forces a sequence point, then everything up 1306 to the sequence point is stored in PBEFORE_SP. Everything else gets stored 1307 in PNO_SP. 1308 Once we return, we will have emitted warnings if any subexpression before 1309 such a sequence point could be undefined. On a higher level, however, the 1310 sequence point may not be relevant, and we'll merge the two lists. 1311 1312 Example: (b++, a) + b; 1313 The call that processes the COMPOUND_EXPR will store the increment of B 1314 in PBEFORE_SP, and the use of A in PNO_SP. The higher-level call that 1315 processes the PLUS_EXPR will need to merge the two lists so that 1316 eventually, all accesses end up on the same list (and we'll warn about the 1317 unordered subexpressions b++ and b. 1318 1319 A note on merging. If we modify the former example so that our expression 1320 becomes 1321 (b++, b) + a 1322 care must be taken not simply to add all three expressions into the final 1323 PNO_SP list. The function merge_tlist takes care of that by merging the 1324 before-SP list of the COMPOUND_EXPR into its after-SP list in a special 1325 way, so that no more than one access to B is recorded. */ 1326 1327static void 1328verify_tree (tree x, struct tlist **pbefore_sp, struct tlist **pno_sp, 1329 tree writer) 1330{ 1331 struct tlist *tmp_before, *tmp_nosp, *tmp_list2, *tmp_list3; 1332 enum tree_code code; 1333 enum tree_code_class cl; 1334 1335 /* X may be NULL if it is the operand of an empty statement expression 1336 ({ }). */ 1337 if (x == NULL) 1338 return; 1339 1340 restart: 1341 code = TREE_CODE (x); 1342 cl = TREE_CODE_CLASS (code); 1343 1344 if (warning_candidate_p (x)) 1345 { 1346 *pno_sp = new_tlist (*pno_sp, x, writer); 1347 return; 1348 } 1349 1350 switch (code) 1351 { 1352 case CONSTRUCTOR: 1353 return; 1354 1355 case COMPOUND_EXPR: 1356 case TRUTH_ANDIF_EXPR: 1357 case TRUTH_ORIF_EXPR: 1358 tmp_before = tmp_nosp = tmp_list3 = 0; 1359 verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE); 1360 warn_for_collisions (tmp_nosp); 1361 merge_tlist (pbefore_sp, tmp_before, 0); 1362 merge_tlist (pbefore_sp, tmp_nosp, 0); 1363 verify_tree (TREE_OPERAND (x, 1), &tmp_list3, pno_sp, NULL_TREE); 1364 merge_tlist (pbefore_sp, tmp_list3, 0); 1365 return; 1366 1367 case COND_EXPR: 1368 tmp_before = tmp_list2 = 0; 1369 verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_list2, NULL_TREE); 1370 warn_for_collisions (tmp_list2); 1371 merge_tlist (pbefore_sp, tmp_before, 0); 1372 merge_tlist (pbefore_sp, tmp_list2, 1); 1373 1374 tmp_list3 = tmp_nosp = 0; 1375 verify_tree (TREE_OPERAND (x, 1), &tmp_list3, &tmp_nosp, NULL_TREE); 1376 warn_for_collisions (tmp_nosp); 1377 merge_tlist (pbefore_sp, tmp_list3, 0); 1378 1379 tmp_list3 = tmp_list2 = 0; 1380 verify_tree (TREE_OPERAND (x, 2), &tmp_list3, &tmp_list2, NULL_TREE); 1381 warn_for_collisions (tmp_list2); 1382 merge_tlist (pbefore_sp, tmp_list3, 0); 1383 /* Rather than add both tmp_nosp and tmp_list2, we have to merge the 1384 two first, to avoid warning for (a ? b++ : b++). */ 1385 merge_tlist (&tmp_nosp, tmp_list2, 0); 1386 add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0); 1387 return; 1388 1389 case PREDECREMENT_EXPR: 1390 case PREINCREMENT_EXPR: 1391 case POSTDECREMENT_EXPR: 1392 case POSTINCREMENT_EXPR: 1393 verify_tree (TREE_OPERAND (x, 0), pno_sp, pno_sp, x); 1394 return; 1395 1396 case MODIFY_EXPR: 1397 tmp_before = tmp_nosp = tmp_list3 = 0; 1398 verify_tree (TREE_OPERAND (x, 1), &tmp_before, &tmp_nosp, NULL_TREE); 1399 verify_tree (TREE_OPERAND (x, 0), &tmp_list3, &tmp_list3, x); 1400 /* Expressions inside the LHS are not ordered wrt. the sequence points 1401 in the RHS. Example: 1402 *a = (a++, 2) 1403 Despite the fact that the modification of "a" is in the before_sp 1404 list (tmp_before), it conflicts with the use of "a" in the LHS. 1405 We can handle this by adding the contents of tmp_list3 1406 to those of tmp_before, and redoing the collision warnings for that 1407 list. */ 1408 add_tlist (&tmp_before, tmp_list3, x, 1); 1409 warn_for_collisions (tmp_before); 1410 /* Exclude the LHS itself here; we first have to merge it into the 1411 tmp_nosp list. This is done to avoid warning for "a = a"; if we 1412 didn't exclude the LHS, we'd get it twice, once as a read and once 1413 as a write. */ 1414 add_tlist (pno_sp, tmp_list3, x, 0); 1415 warn_for_collisions_1 (TREE_OPERAND (x, 0), x, tmp_nosp, 1); 1416 1417 merge_tlist (pbefore_sp, tmp_before, 0); 1418 if (warning_candidate_p (TREE_OPERAND (x, 0))) 1419 merge_tlist (&tmp_nosp, new_tlist (NULL, TREE_OPERAND (x, 0), x), 0); 1420 add_tlist (pno_sp, tmp_nosp, NULL_TREE, 1); 1421 return; 1422 1423 case CALL_EXPR: 1424 /* We need to warn about conflicts among arguments and conflicts between 1425 args and the function address. Side effects of the function address, 1426 however, are not ordered by the sequence point of the call. */ 1427 tmp_before = tmp_nosp = tmp_list2 = tmp_list3 = 0; 1428 verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE); 1429 if (TREE_OPERAND (x, 1)) 1430 verify_tree (TREE_OPERAND (x, 1), &tmp_list2, &tmp_list3, NULL_TREE); 1431 merge_tlist (&tmp_list3, tmp_list2, 0); 1432 add_tlist (&tmp_before, tmp_list3, NULL_TREE, 0); 1433 add_tlist (&tmp_before, tmp_nosp, NULL_TREE, 0); 1434 warn_for_collisions (tmp_before); 1435 add_tlist (pbefore_sp, tmp_before, NULL_TREE, 0); 1436 return; 1437 1438 case TREE_LIST: 1439 /* Scan all the list, e.g. indices of multi dimensional array. */ 1440 while (x) 1441 { 1442 tmp_before = tmp_nosp = 0; 1443 verify_tree (TREE_VALUE (x), &tmp_before, &tmp_nosp, NULL_TREE); 1444 merge_tlist (&tmp_nosp, tmp_before, 0); 1445 add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0); 1446 x = TREE_CHAIN (x); 1447 } 1448 return; 1449 1450 case SAVE_EXPR: 1451 { 1452 struct tlist_cache *t; 1453 for (t = save_expr_cache; t; t = t->next) 1454 if (t->expr == x) 1455 break; 1456 1457 if (!t) 1458 { 1459 t = XOBNEW (&tlist_obstack, struct tlist_cache); 1460 t->next = save_expr_cache; 1461 t->expr = x; 1462 save_expr_cache = t; 1463 1464 tmp_before = tmp_nosp = 0; 1465 verify_tree (TREE_OPERAND (x, 0), &tmp_before, &tmp_nosp, NULL_TREE); 1466 warn_for_collisions (tmp_nosp); 1467 1468 tmp_list3 = 0; 1469 while (tmp_nosp) 1470 { 1471 struct tlist *t = tmp_nosp; 1472 tmp_nosp = t->next; 1473 merge_tlist (&tmp_list3, t, 0); 1474 } 1475 t->cache_before_sp = tmp_before; 1476 t->cache_after_sp = tmp_list3; 1477 } 1478 merge_tlist (pbefore_sp, t->cache_before_sp, 1); 1479 add_tlist (pno_sp, t->cache_after_sp, NULL_TREE, 1); 1480 return; 1481 } 1482 1483 default: 1484 /* For other expressions, simply recurse on their operands. 1485 Manual tail recursion for unary expressions. 1486 Other non-expressions need not be processed. */ 1487 if (cl == tcc_unary) 1488 { 1489 x = TREE_OPERAND (x, 0); 1490 writer = 0; 1491 goto restart; 1492 } 1493 else if (IS_EXPR_CODE_CLASS (cl)) 1494 { 1495 int lp; 1496 int max = TREE_CODE_LENGTH (TREE_CODE (x)); 1497 for (lp = 0; lp < max; lp++) 1498 { 1499 tmp_before = tmp_nosp = 0; 1500 verify_tree (TREE_OPERAND (x, lp), &tmp_before, &tmp_nosp, 0); 1501 merge_tlist (&tmp_nosp, tmp_before, 0); 1502 add_tlist (pno_sp, tmp_nosp, NULL_TREE, 0); 1503 } 1504 } 1505 return; 1506 } 1507} 1508 1509/* Try to warn for undefined behavior in EXPR due to missing sequence 1510 points. */ 1511 1512void 1513verify_sequence_points (tree expr) 1514{ 1515 struct tlist *before_sp = 0, *after_sp = 0; 1516 1517 warned_ids = 0; 1518 save_expr_cache = 0; 1519 if (tlist_firstobj == 0) 1520 { 1521 gcc_obstack_init (&tlist_obstack); 1522 tlist_firstobj = (char *) obstack_alloc (&tlist_obstack, 0); 1523 } 1524 1525 verify_tree (expr, &before_sp, &after_sp, 0); 1526 warn_for_collisions (after_sp); 1527 obstack_free (&tlist_obstack, tlist_firstobj); 1528} 1529 1530/* Validate the expression after `case' and apply default promotions. */ 1531 1532static tree 1533check_case_value (tree value) 1534{ 1535 if (value == NULL_TREE) 1536 return value; 1537 1538 /* ??? Can we ever get nops here for a valid case value? We 1539 shouldn't for C. */ 1540 STRIP_TYPE_NOPS (value); 1541 /* In C++, the following is allowed: 1542 1543 const int i = 3; 1544 switch (...) { case i: ... } 1545 1546 So, we try to reduce the VALUE to a constant that way. */ 1547 if (c_dialect_cxx ()) 1548 { 1549 value = decl_constant_value (value); 1550 STRIP_TYPE_NOPS (value); 1551 value = fold (value); 1552 } 1553 1554 if (TREE_CODE (value) == INTEGER_CST) 1555 /* Promote char or short to int. */ 1556 value = perform_integral_promotions (value); 1557 else if (value != error_mark_node) 1558 { 1559 error ("case label does not reduce to an integer constant"); 1560 value = error_mark_node; 1561 } 1562 1563 constant_expression_warning (value); 1564 1565 return value; 1566} 1567 1568/* See if the case values LOW and HIGH are in the range of the original 1569 type (i.e. before the default conversion to int) of the switch testing 1570 expression. 1571 TYPE is the promoted type of the testing expression, and ORIG_TYPE is 1572 the type before promoting it. CASE_LOW_P is a pointer to the lower 1573 bound of the case label, and CASE_HIGH_P is the upper bound or NULL 1574 if the case is not a case range. 1575 The caller has to make sure that we are not called with NULL for 1576 CASE_LOW_P (i.e. the default case). 1577 Returns true if the case label is in range of ORIG_TYPE (saturated or 1578 untouched) or false if the label is out of range. */ 1579 1580static bool 1581check_case_bounds (tree type, tree orig_type, 1582 tree *case_low_p, tree *case_high_p) 1583{ 1584 tree min_value, max_value; 1585 tree case_low = *case_low_p; 1586 tree case_high = case_high_p ? *case_high_p : case_low; 1587 1588 /* If there was a problem with the original type, do nothing. */ 1589 if (orig_type == error_mark_node) 1590 return true; 1591 1592 min_value = TYPE_MIN_VALUE (orig_type); 1593 max_value = TYPE_MAX_VALUE (orig_type); 1594 1595 /* Case label is less than minimum for type. */ 1596 if (tree_int_cst_compare (case_low, min_value) < 0 1597 && tree_int_cst_compare (case_high, min_value) < 0) 1598 { 1599 warning (0, "case label value is less than minimum value for type"); 1600 return false; 1601 } 1602 1603 /* Case value is greater than maximum for type. */ 1604 if (tree_int_cst_compare (case_low, max_value) > 0 1605 && tree_int_cst_compare (case_high, max_value) > 0) 1606 { 1607 warning (0, "case label value exceeds maximum value for type"); 1608 return false; 1609 } 1610 1611 /* Saturate lower case label value to minimum. */ 1612 if (tree_int_cst_compare (case_high, min_value) >= 0 1613 && tree_int_cst_compare (case_low, min_value) < 0) 1614 { 1615 warning (0, "lower value in case label range" 1616 " less than minimum value for type"); 1617 case_low = min_value; 1618 } 1619 1620 /* Saturate upper case label value to maximum. */ 1621 if (tree_int_cst_compare (case_low, max_value) <= 0 1622 && tree_int_cst_compare (case_high, max_value) > 0) 1623 { 1624 warning (0, "upper value in case label range" 1625 " exceeds maximum value for type"); 1626 case_high = max_value; 1627 } 1628 1629 if (*case_low_p != case_low) 1630 *case_low_p = convert (type, case_low); 1631 if (case_high_p && *case_high_p != case_high) 1632 *case_high_p = convert (type, case_high); 1633 1634 return true; 1635} 1636 1637/* Return an integer type with BITS bits of precision, 1638 that is unsigned if UNSIGNEDP is nonzero, otherwise signed. */ 1639 1640tree 1641c_common_type_for_size (unsigned int bits, int unsignedp) 1642{ 1643 if (bits == TYPE_PRECISION (integer_type_node)) 1644 return unsignedp ? unsigned_type_node : integer_type_node; 1645 1646 if (bits == TYPE_PRECISION (signed_char_type_node)) 1647 return unsignedp ? unsigned_char_type_node : signed_char_type_node; 1648 1649 if (bits == TYPE_PRECISION (short_integer_type_node)) 1650 return unsignedp ? short_unsigned_type_node : short_integer_type_node; 1651 1652 if (bits == TYPE_PRECISION (long_integer_type_node)) 1653 return unsignedp ? long_unsigned_type_node : long_integer_type_node; 1654 1655 if (bits == TYPE_PRECISION (long_long_integer_type_node)) 1656 return (unsignedp ? long_long_unsigned_type_node 1657 : long_long_integer_type_node); 1658 1659 if (bits == TYPE_PRECISION (widest_integer_literal_type_node)) 1660 return (unsignedp ? widest_unsigned_literal_type_node 1661 : widest_integer_literal_type_node); 1662 1663 if (bits <= TYPE_PRECISION (intQI_type_node)) 1664 return unsignedp ? unsigned_intQI_type_node : intQI_type_node; 1665 1666 if (bits <= TYPE_PRECISION (intHI_type_node)) 1667 return unsignedp ? unsigned_intHI_type_node : intHI_type_node; 1668 1669 if (bits <= TYPE_PRECISION (intSI_type_node)) 1670 return unsignedp ? unsigned_intSI_type_node : intSI_type_node; 1671 1672 if (bits <= TYPE_PRECISION (intDI_type_node)) 1673 return unsignedp ? unsigned_intDI_type_node : intDI_type_node; 1674 1675 return 0; 1676} 1677 1678/* Used for communication between c_common_type_for_mode and 1679 c_register_builtin_type. */ 1680static GTY(()) tree registered_builtin_types; 1681 1682/* Return a data type that has machine mode MODE. 1683 If the mode is an integer, 1684 then UNSIGNEDP selects between signed and unsigned types. */ 1685 1686tree 1687c_common_type_for_mode (enum machine_mode mode, int unsignedp) 1688{ 1689 tree t; 1690 1691 if (mode == TYPE_MODE (integer_type_node)) 1692 return unsignedp ? unsigned_type_node : integer_type_node; 1693 1694 if (mode == TYPE_MODE (signed_char_type_node)) 1695 return unsignedp ? unsigned_char_type_node : signed_char_type_node; 1696 1697 if (mode == TYPE_MODE (short_integer_type_node)) 1698 return unsignedp ? short_unsigned_type_node : short_integer_type_node; 1699 1700 if (mode == TYPE_MODE (long_integer_type_node)) 1701 return unsignedp ? long_unsigned_type_node : long_integer_type_node; 1702 1703 if (mode == TYPE_MODE (long_long_integer_type_node)) 1704 return unsignedp ? long_long_unsigned_type_node : long_long_integer_type_node; 1705 1706 if (mode == TYPE_MODE (widest_integer_literal_type_node)) 1707 return unsignedp ? widest_unsigned_literal_type_node 1708 : widest_integer_literal_type_node; 1709 1710 if (mode == QImode) 1711 return unsignedp ? unsigned_intQI_type_node : intQI_type_node; 1712 1713 if (mode == HImode) 1714 return unsignedp ? unsigned_intHI_type_node : intHI_type_node; 1715 1716 if (mode == SImode) 1717 return unsignedp ? unsigned_intSI_type_node : intSI_type_node; 1718 1719 if (mode == DImode) 1720 return unsignedp ? unsigned_intDI_type_node : intDI_type_node; 1721 1722#if HOST_BITS_PER_WIDE_INT >= 64 1723 if (mode == TYPE_MODE (intTI_type_node)) 1724 return unsignedp ? unsigned_intTI_type_node : intTI_type_node; 1725#endif 1726 1727 if (mode == TYPE_MODE (float_type_node)) 1728 return float_type_node; 1729 1730 if (mode == TYPE_MODE (double_type_node)) 1731 return double_type_node; 1732 1733 if (mode == TYPE_MODE (long_double_type_node)) 1734 return long_double_type_node; 1735 1736 if (mode == TYPE_MODE (void_type_node)) 1737 return void_type_node; 1738 1739 if (mode == TYPE_MODE (build_pointer_type (char_type_node))) 1740 return (unsignedp 1741 ? make_unsigned_type (GET_MODE_PRECISION (mode)) 1742 : make_signed_type (GET_MODE_PRECISION (mode))); 1743 1744 if (mode == TYPE_MODE (build_pointer_type (integer_type_node))) 1745 return (unsignedp 1746 ? make_unsigned_type (GET_MODE_PRECISION (mode)) 1747 : make_signed_type (GET_MODE_PRECISION (mode))); 1748 1749 if (COMPLEX_MODE_P (mode)) 1750 { 1751 enum machine_mode inner_mode; 1752 tree inner_type; 1753 1754 if (mode == TYPE_MODE (complex_float_type_node)) 1755 return complex_float_type_node; 1756 if (mode == TYPE_MODE (complex_double_type_node)) 1757 return complex_double_type_node; 1758 if (mode == TYPE_MODE (complex_long_double_type_node)) 1759 return complex_long_double_type_node; 1760 1761 if (mode == TYPE_MODE (complex_integer_type_node) && !unsignedp) 1762 return complex_integer_type_node; 1763 1764 inner_mode = GET_MODE_INNER (mode); 1765 inner_type = c_common_type_for_mode (inner_mode, unsignedp); 1766 if (inner_type != NULL_TREE) 1767 return build_complex_type (inner_type); 1768 } 1769 else if (VECTOR_MODE_P (mode)) 1770 { 1771 enum machine_mode inner_mode = GET_MODE_INNER (mode); 1772 tree inner_type = c_common_type_for_mode (inner_mode, unsignedp); 1773 if (inner_type != NULL_TREE) 1774 return build_vector_type_for_mode (inner_type, mode); 1775 } 1776 1777 if (mode == TYPE_MODE (dfloat32_type_node)) 1778 return dfloat32_type_node; 1779 if (mode == TYPE_MODE (dfloat64_type_node)) 1780 return dfloat64_type_node; 1781 if (mode == TYPE_MODE (dfloat128_type_node)) 1782 return dfloat128_type_node; 1783 1784 for (t = registered_builtin_types; t; t = TREE_CHAIN (t)) 1785 if (TYPE_MODE (TREE_VALUE (t)) == mode) 1786 return TREE_VALUE (t); 1787 1788 return 0; 1789} 1790 1791/* Return an unsigned type the same as TYPE in other respects. */ 1792tree 1793c_common_unsigned_type (tree type) 1794{ 1795 tree type1 = TYPE_MAIN_VARIANT (type); 1796 if (type1 == signed_char_type_node || type1 == char_type_node) 1797 return unsigned_char_type_node; 1798 if (type1 == integer_type_node) 1799 return unsigned_type_node; 1800 if (type1 == short_integer_type_node) 1801 return short_unsigned_type_node; 1802 if (type1 == long_integer_type_node) 1803 return long_unsigned_type_node; 1804 if (type1 == long_long_integer_type_node) 1805 return long_long_unsigned_type_node; 1806 if (type1 == widest_integer_literal_type_node) 1807 return widest_unsigned_literal_type_node; 1808#if HOST_BITS_PER_WIDE_INT >= 64 1809 if (type1 == intTI_type_node) 1810 return unsigned_intTI_type_node; 1811#endif 1812 if (type1 == intDI_type_node) 1813 return unsigned_intDI_type_node; 1814 if (type1 == intSI_type_node) 1815 return unsigned_intSI_type_node; 1816 if (type1 == intHI_type_node) 1817 return unsigned_intHI_type_node; 1818 if (type1 == intQI_type_node) 1819 return unsigned_intQI_type_node; 1820 1821 return c_common_signed_or_unsigned_type (1, type); 1822} 1823 1824/* Return a signed type the same as TYPE in other respects. */ 1825 1826tree 1827c_common_signed_type (tree type) 1828{ 1829 tree type1 = TYPE_MAIN_VARIANT (type); 1830 if (type1 == unsigned_char_type_node || type1 == char_type_node) 1831 return signed_char_type_node; 1832 if (type1 == unsigned_type_node) 1833 return integer_type_node; 1834 if (type1 == short_unsigned_type_node) 1835 return short_integer_type_node; 1836 if (type1 == long_unsigned_type_node) 1837 return long_integer_type_node; 1838 if (type1 == long_long_unsigned_type_node) 1839 return long_long_integer_type_node; 1840 if (type1 == widest_unsigned_literal_type_node) 1841 return widest_integer_literal_type_node; 1842#if HOST_BITS_PER_WIDE_INT >= 64 1843 if (type1 == unsigned_intTI_type_node) 1844 return intTI_type_node; 1845#endif 1846 if (type1 == unsigned_intDI_type_node) 1847 return intDI_type_node; 1848 if (type1 == unsigned_intSI_type_node) 1849 return intSI_type_node; 1850 if (type1 == unsigned_intHI_type_node) 1851 return intHI_type_node; 1852 if (type1 == unsigned_intQI_type_node) 1853 return intQI_type_node; 1854 1855 return c_common_signed_or_unsigned_type (0, type); 1856} 1857 1858/* Return a type the same as TYPE except unsigned or 1859 signed according to UNSIGNEDP. */ 1860 1861tree 1862c_common_signed_or_unsigned_type (int unsignedp, tree type) 1863{ 1864 if (!INTEGRAL_TYPE_P (type) 1865 || TYPE_UNSIGNED (type) == unsignedp) 1866 return type; 1867 1868 /* For ENUMERAL_TYPEs in C++, must check the mode of the types, not 1869 the precision; they have precision set to match their range, but 1870 may use a wider mode to match an ABI. If we change modes, we may 1871 wind up with bad conversions. For INTEGER_TYPEs in C, must check 1872 the precision as well, so as to yield correct results for 1873 bit-field types. C++ does not have these separate bit-field 1874 types, and producing a signed or unsigned variant of an 1875 ENUMERAL_TYPE may cause other problems as well. */ 1876 1877#define TYPE_OK(node) \ 1878 (TYPE_MODE (type) == TYPE_MODE (node) \ 1879 && (c_dialect_cxx () || TYPE_PRECISION (type) == TYPE_PRECISION (node))) 1880 if (TYPE_OK (signed_char_type_node)) 1881 return unsignedp ? unsigned_char_type_node : signed_char_type_node; 1882 if (TYPE_OK (integer_type_node)) 1883 return unsignedp ? unsigned_type_node : integer_type_node; 1884 if (TYPE_OK (short_integer_type_node)) 1885 return unsignedp ? short_unsigned_type_node : short_integer_type_node; 1886 if (TYPE_OK (long_integer_type_node)) 1887 return unsignedp ? long_unsigned_type_node : long_integer_type_node; 1888 if (TYPE_OK (long_long_integer_type_node)) 1889 return (unsignedp ? long_long_unsigned_type_node 1890 : long_long_integer_type_node); 1891 if (TYPE_OK (widest_integer_literal_type_node)) 1892 return (unsignedp ? widest_unsigned_literal_type_node 1893 : widest_integer_literal_type_node); 1894 1895#if HOST_BITS_PER_WIDE_INT >= 64 1896 if (TYPE_OK (intTI_type_node)) 1897 return unsignedp ? unsigned_intTI_type_node : intTI_type_node; 1898#endif 1899 if (TYPE_OK (intDI_type_node)) 1900 return unsignedp ? unsigned_intDI_type_node : intDI_type_node; 1901 if (TYPE_OK (intSI_type_node)) 1902 return unsignedp ? unsigned_intSI_type_node : intSI_type_node; 1903 if (TYPE_OK (intHI_type_node)) 1904 return unsignedp ? unsigned_intHI_type_node : intHI_type_node; 1905 if (TYPE_OK (intQI_type_node)) 1906 return unsignedp ? unsigned_intQI_type_node : intQI_type_node; 1907#undef TYPE_OK 1908 1909 if (c_dialect_cxx ()) 1910 return type; 1911 else 1912 return build_nonstandard_integer_type (TYPE_PRECISION (type), unsignedp); 1913} 1914 1915/* Build a bit-field integer type for the given WIDTH and UNSIGNEDP. */ 1916 1917tree 1918c_build_bitfield_integer_type (unsigned HOST_WIDE_INT width, int unsignedp) 1919{ 1920 /* Extended integer types of the same width as a standard type have 1921 lesser rank, so those of the same width as int promote to int or 1922 unsigned int and are valid for printf formats expecting int or 1923 unsigned int. To avoid such special cases, avoid creating 1924 extended integer types for bit-fields if a standard integer type 1925 is available. */ 1926 if (width == TYPE_PRECISION (integer_type_node)) 1927 return unsignedp ? unsigned_type_node : integer_type_node; 1928 if (width == TYPE_PRECISION (signed_char_type_node)) 1929 return unsignedp ? unsigned_char_type_node : signed_char_type_node; 1930 if (width == TYPE_PRECISION (short_integer_type_node)) 1931 return unsignedp ? short_unsigned_type_node : short_integer_type_node; 1932 if (width == TYPE_PRECISION (long_integer_type_node)) 1933 return unsignedp ? long_unsigned_type_node : long_integer_type_node; 1934 if (width == TYPE_PRECISION (long_long_integer_type_node)) 1935 return (unsignedp ? long_long_unsigned_type_node 1936 : long_long_integer_type_node); 1937 return build_nonstandard_integer_type (width, unsignedp); 1938} 1939 1940/* The C version of the register_builtin_type langhook. */ 1941 1942void 1943c_register_builtin_type (tree type, const char* name) 1944{ 1945 tree decl; 1946 1947 decl = build_decl (TYPE_DECL, get_identifier (name), type); 1948 DECL_ARTIFICIAL (decl) = 1; 1949 if (!TYPE_NAME (type)) 1950 TYPE_NAME (type) = decl; 1951 pushdecl (decl); 1952 1953 registered_builtin_types = tree_cons (0, type, registered_builtin_types); 1954} 1955 1956 1957/* Return the minimum number of bits needed to represent VALUE in a 1958 signed or unsigned type, UNSIGNEDP says which. */ 1959 1960unsigned int 1961min_precision (tree value, int unsignedp) 1962{ 1963 int log; 1964 1965 /* If the value is negative, compute its negative minus 1. The latter 1966 adjustment is because the absolute value of the largest negative value 1967 is one larger than the largest positive value. This is equivalent to 1968 a bit-wise negation, so use that operation instead. */ 1969 1970 if (tree_int_cst_sgn (value) < 0) 1971 value = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (value), value); 1972 1973 /* Return the number of bits needed, taking into account the fact 1974 that we need one more bit for a signed than unsigned type. */ 1975 1976 if (integer_zerop (value)) 1977 log = 0; 1978 else 1979 log = tree_floor_log2 (value); 1980 1981 return log + 1 + !unsignedp; 1982} 1983 1984/* Print an error message for invalid operands to arith operation 1985 CODE. */ 1986 1987void 1988binary_op_error (enum tree_code code) 1989{ 1990 const char *opname; 1991 1992 switch (code) 1993 { 1994 case PLUS_EXPR: 1995 opname = "+"; break; 1996 case MINUS_EXPR: 1997 opname = "-"; break; 1998 case MULT_EXPR: 1999 opname = "*"; break; 2000 case MAX_EXPR: 2001 opname = "max"; break; 2002 case MIN_EXPR: 2003 opname = "min"; break; 2004 case EQ_EXPR: 2005 opname = "=="; break; 2006 case NE_EXPR: 2007 opname = "!="; break; 2008 case LE_EXPR: 2009 opname = "<="; break; 2010 case GE_EXPR: 2011 opname = ">="; break; 2012 case LT_EXPR: 2013 opname = "<"; break; 2014 case GT_EXPR: 2015 opname = ">"; break; 2016 case LSHIFT_EXPR: 2017 opname = "<<"; break; 2018 case RSHIFT_EXPR: 2019 opname = ">>"; break; 2020 case TRUNC_MOD_EXPR: 2021 case FLOOR_MOD_EXPR: 2022 opname = "%"; break; 2023 case TRUNC_DIV_EXPR: 2024 case FLOOR_DIV_EXPR: 2025 opname = "/"; break; 2026 case BIT_AND_EXPR: 2027 opname = "&"; break; 2028 case BIT_IOR_EXPR: 2029 opname = "|"; break; 2030 case TRUTH_ANDIF_EXPR: 2031 opname = "&&"; break; 2032 case TRUTH_ORIF_EXPR: 2033 opname = "||"; break; 2034 case BIT_XOR_EXPR: 2035 opname = "^"; break; 2036 default: 2037 gcc_unreachable (); 2038 } 2039 error ("invalid operands to binary %s", opname); 2040} 2041 2042/* Subroutine of build_binary_op, used for comparison operations. 2043 See if the operands have both been converted from subword integer types 2044 and, if so, perhaps change them both back to their original type. 2045 This function is also responsible for converting the two operands 2046 to the proper common type for comparison. 2047 2048 The arguments of this function are all pointers to local variables 2049 of build_binary_op: OP0_PTR is &OP0, OP1_PTR is &OP1, 2050 RESTYPE_PTR is &RESULT_TYPE and RESCODE_PTR is &RESULTCODE. 2051 2052 If this function returns nonzero, it means that the comparison has 2053 a constant value. What this function returns is an expression for 2054 that value. */ 2055 2056tree 2057shorten_compare (tree *op0_ptr, tree *op1_ptr, tree *restype_ptr, 2058 enum tree_code *rescode_ptr) 2059{ 2060 tree type; 2061 tree op0 = *op0_ptr; 2062 tree op1 = *op1_ptr; 2063 int unsignedp0, unsignedp1; 2064 int real1, real2; 2065 tree primop0, primop1; 2066 enum tree_code code = *rescode_ptr; 2067 2068 /* Throw away any conversions to wider types 2069 already present in the operands. */ 2070 2071 primop0 = get_narrower (op0, &unsignedp0); 2072 primop1 = get_narrower (op1, &unsignedp1); 2073 2074 /* Handle the case that OP0 does not *contain* a conversion 2075 but it *requires* conversion to FINAL_TYPE. */ 2076 2077 if (op0 == primop0 && TREE_TYPE (op0) != *restype_ptr) 2078 unsignedp0 = TYPE_UNSIGNED (TREE_TYPE (op0)); 2079 if (op1 == primop1 && TREE_TYPE (op1) != *restype_ptr) 2080 unsignedp1 = TYPE_UNSIGNED (TREE_TYPE (op1)); 2081 2082 /* If one of the operands must be floated, we cannot optimize. */ 2083 real1 = TREE_CODE (TREE_TYPE (primop0)) == REAL_TYPE; 2084 real2 = TREE_CODE (TREE_TYPE (primop1)) == REAL_TYPE; 2085 2086 /* If first arg is constant, swap the args (changing operation 2087 so value is preserved), for canonicalization. Don't do this if 2088 the second arg is 0. */ 2089 2090 if (TREE_CONSTANT (primop0) 2091 && !integer_zerop (primop1) && !real_zerop (primop1)) 2092 { 2093 tree tem = primop0; 2094 int temi = unsignedp0; 2095 primop0 = primop1; 2096 primop1 = tem; 2097 tem = op0; 2098 op0 = op1; 2099 op1 = tem; 2100 *op0_ptr = op0; 2101 *op1_ptr = op1; 2102 unsignedp0 = unsignedp1; 2103 unsignedp1 = temi; 2104 temi = real1; 2105 real1 = real2; 2106 real2 = temi; 2107 2108 switch (code) 2109 { 2110 case LT_EXPR: 2111 code = GT_EXPR; 2112 break; 2113 case GT_EXPR: 2114 code = LT_EXPR; 2115 break; 2116 case LE_EXPR: 2117 code = GE_EXPR; 2118 break; 2119 case GE_EXPR: 2120 code = LE_EXPR; 2121 break; 2122 default: 2123 break; 2124 } 2125 *rescode_ptr = code; 2126 } 2127 2128 /* If comparing an integer against a constant more bits wide, 2129 maybe we can deduce a value of 1 or 0 independent of the data. 2130 Or else truncate the constant now 2131 rather than extend the variable at run time. 2132 2133 This is only interesting if the constant is the wider arg. 2134 Also, it is not safe if the constant is unsigned and the 2135 variable arg is signed, since in this case the variable 2136 would be sign-extended and then regarded as unsigned. 2137 Our technique fails in this case because the lowest/highest 2138 possible unsigned results don't follow naturally from the 2139 lowest/highest possible values of the variable operand. 2140 For just EQ_EXPR and NE_EXPR there is another technique that 2141 could be used: see if the constant can be faithfully represented 2142 in the other operand's type, by truncating it and reextending it 2143 and see if that preserves the constant's value. */ 2144 2145 if (!real1 && !real2 2146 && TREE_CODE (primop1) == INTEGER_CST 2147 && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr)) 2148 { 2149 int min_gt, max_gt, min_lt, max_lt; 2150 tree maxval, minval; 2151 /* 1 if comparison is nominally unsigned. */ 2152 int unsignedp = TYPE_UNSIGNED (*restype_ptr); 2153 tree val; 2154 2155 type = c_common_signed_or_unsigned_type (unsignedp0, 2156 TREE_TYPE (primop0)); 2157 2158 maxval = TYPE_MAX_VALUE (type); 2159 minval = TYPE_MIN_VALUE (type); 2160 2161 if (unsignedp && !unsignedp0) 2162 *restype_ptr = c_common_signed_type (*restype_ptr); 2163 2164 if (TREE_TYPE (primop1) != *restype_ptr) 2165 { 2166 /* Convert primop1 to target type, but do not introduce 2167 additional overflow. We know primop1 is an int_cst. */ 2168 tree tmp = build_int_cst_wide (*restype_ptr, 2169 TREE_INT_CST_LOW (primop1), 2170 TREE_INT_CST_HIGH (primop1)); 2171 2172 primop1 = force_fit_type (tmp, 0, TREE_OVERFLOW (primop1), 2173 TREE_CONSTANT_OVERFLOW (primop1)); 2174 } 2175 if (type != *restype_ptr) 2176 { 2177 minval = convert (*restype_ptr, minval); 2178 maxval = convert (*restype_ptr, maxval); 2179 } 2180 2181 if (unsignedp && unsignedp0) 2182 { 2183 min_gt = INT_CST_LT_UNSIGNED (primop1, minval); 2184 max_gt = INT_CST_LT_UNSIGNED (primop1, maxval); 2185 min_lt = INT_CST_LT_UNSIGNED (minval, primop1); 2186 max_lt = INT_CST_LT_UNSIGNED (maxval, primop1); 2187 } 2188 else 2189 { 2190 min_gt = INT_CST_LT (primop1, minval); 2191 max_gt = INT_CST_LT (primop1, maxval); 2192 min_lt = INT_CST_LT (minval, primop1); 2193 max_lt = INT_CST_LT (maxval, primop1); 2194 } 2195 2196 val = 0; 2197 /* This used to be a switch, but Genix compiler can't handle that. */ 2198 if (code == NE_EXPR) 2199 { 2200 if (max_lt || min_gt) 2201 val = truthvalue_true_node; 2202 } 2203 else if (code == EQ_EXPR) 2204 { 2205 if (max_lt || min_gt) 2206 val = truthvalue_false_node; 2207 } 2208 else if (code == LT_EXPR) 2209 { 2210 if (max_lt) 2211 val = truthvalue_true_node; 2212 if (!min_lt) 2213 val = truthvalue_false_node; 2214 } 2215 else if (code == GT_EXPR) 2216 { 2217 if (min_gt) 2218 val = truthvalue_true_node; 2219 if (!max_gt) 2220 val = truthvalue_false_node; 2221 } 2222 else if (code == LE_EXPR) 2223 { 2224 if (!max_gt) 2225 val = truthvalue_true_node; 2226 if (min_gt) 2227 val = truthvalue_false_node; 2228 } 2229 else if (code == GE_EXPR) 2230 { 2231 if (!min_lt) 2232 val = truthvalue_true_node; 2233 if (max_lt) 2234 val = truthvalue_false_node; 2235 } 2236 2237 /* If primop0 was sign-extended and unsigned comparison specd, 2238 we did a signed comparison above using the signed type bounds. 2239 But the comparison we output must be unsigned. 2240 2241 Also, for inequalities, VAL is no good; but if the signed 2242 comparison had *any* fixed result, it follows that the 2243 unsigned comparison just tests the sign in reverse 2244 (positive values are LE, negative ones GE). 2245 So we can generate an unsigned comparison 2246 against an extreme value of the signed type. */ 2247 2248 if (unsignedp && !unsignedp0) 2249 { 2250 if (val != 0) 2251 switch (code) 2252 { 2253 case LT_EXPR: 2254 case GE_EXPR: 2255 primop1 = TYPE_MIN_VALUE (type); 2256 val = 0; 2257 break; 2258 2259 case LE_EXPR: 2260 case GT_EXPR: 2261 primop1 = TYPE_MAX_VALUE (type); 2262 val = 0; 2263 break; 2264 2265 default: 2266 break; 2267 } 2268 type = c_common_unsigned_type (type); 2269 } 2270 2271 if (TREE_CODE (primop0) != INTEGER_CST) 2272 { 2273 if (val == truthvalue_false_node) 2274 warning (0, "comparison is always false due to limited range of data type"); 2275 if (val == truthvalue_true_node) 2276 warning (0, "comparison is always true due to limited range of data type"); 2277 } 2278 2279 if (val != 0) 2280 { 2281 /* Don't forget to evaluate PRIMOP0 if it has side effects. */ 2282 if (TREE_SIDE_EFFECTS (primop0)) 2283 return build2 (COMPOUND_EXPR, TREE_TYPE (val), primop0, val); 2284 return val; 2285 } 2286 2287 /* Value is not predetermined, but do the comparison 2288 in the type of the operand that is not constant. 2289 TYPE is already properly set. */ 2290 } 2291 2292 /* If either arg is decimal float and the other is float, find the 2293 proper common type to use for comparison. */ 2294 else if (real1 && real2 2295 && (DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (primop0))) 2296 || DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (primop1))))) 2297 type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1)); 2298 2299 else if (real1 && real2 2300 && (TYPE_PRECISION (TREE_TYPE (primop0)) 2301 == TYPE_PRECISION (TREE_TYPE (primop1)))) 2302 type = TREE_TYPE (primop0); 2303 2304 /* If args' natural types are both narrower than nominal type 2305 and both extend in the same manner, compare them 2306 in the type of the wider arg. 2307 Otherwise must actually extend both to the nominal 2308 common type lest different ways of extending 2309 alter the result. 2310 (eg, (short)-1 == (unsigned short)-1 should be 0.) */ 2311 2312 else if (unsignedp0 == unsignedp1 && real1 == real2 2313 && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr) 2314 && TYPE_PRECISION (TREE_TYPE (primop1)) < TYPE_PRECISION (*restype_ptr)) 2315 { 2316 type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1)); 2317 type = c_common_signed_or_unsigned_type (unsignedp0 2318 || TYPE_UNSIGNED (*restype_ptr), 2319 type); 2320 /* Make sure shorter operand is extended the right way 2321 to match the longer operand. */ 2322 primop0 2323 = convert (c_common_signed_or_unsigned_type (unsignedp0, 2324 TREE_TYPE (primop0)), 2325 primop0); 2326 primop1 2327 = convert (c_common_signed_or_unsigned_type (unsignedp1, 2328 TREE_TYPE (primop1)), 2329 primop1); 2330 } 2331 else 2332 { 2333 /* Here we must do the comparison on the nominal type 2334 using the args exactly as we received them. */ 2335 type = *restype_ptr; 2336 primop0 = op0; 2337 primop1 = op1; 2338 2339 if (!real1 && !real2 && integer_zerop (primop1) 2340 && TYPE_UNSIGNED (*restype_ptr)) 2341 { 2342 tree value = 0; 2343 switch (code) 2344 { 2345 case GE_EXPR: 2346 /* All unsigned values are >= 0, so we warn if extra warnings 2347 are requested. However, if OP0 is a constant that is 2348 >= 0, the signedness of the comparison isn't an issue, 2349 so suppress the warning. */ 2350 if (extra_warnings && !in_system_header 2351 && !(TREE_CODE (primop0) == INTEGER_CST 2352 && !TREE_OVERFLOW (convert (c_common_signed_type (type), 2353 primop0)))) 2354 warning (0, "comparison of unsigned expression >= 0 is always true"); 2355 value = truthvalue_true_node; 2356 break; 2357 2358 case LT_EXPR: 2359 if (extra_warnings && !in_system_header 2360 && !(TREE_CODE (primop0) == INTEGER_CST 2361 && !TREE_OVERFLOW (convert (c_common_signed_type (type), 2362 primop0)))) 2363 warning (0, "comparison of unsigned expression < 0 is always false"); 2364 value = truthvalue_false_node; 2365 break; 2366 2367 default: 2368 break; 2369 } 2370 2371 if (value != 0) 2372 { 2373 /* Don't forget to evaluate PRIMOP0 if it has side effects. */ 2374 if (TREE_SIDE_EFFECTS (primop0)) 2375 return build2 (COMPOUND_EXPR, TREE_TYPE (value), 2376 primop0, value); 2377 return value; 2378 } 2379 } 2380 } 2381 2382 *op0_ptr = convert (type, primop0); 2383 *op1_ptr = convert (type, primop1); 2384 2385 *restype_ptr = truthvalue_type_node; 2386 2387 return 0; 2388} 2389 2390/* Return a tree for the sum or difference (RESULTCODE says which) 2391 of pointer PTROP and integer INTOP. */ 2392 2393tree 2394pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop) 2395{ 2396 tree size_exp, ret; 2397 2398 /* The result is a pointer of the same type that is being added. */ 2399 2400 tree result_type = TREE_TYPE (ptrop); 2401 2402 if (TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE) 2403 { 2404 if (pedantic || warn_pointer_arith) 2405 pedwarn ("pointer of type %<void *%> used in arithmetic"); 2406 size_exp = integer_one_node; 2407 } 2408 else if (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE) 2409 { 2410 if (pedantic || warn_pointer_arith) 2411 pedwarn ("pointer to a function used in arithmetic"); 2412 size_exp = integer_one_node; 2413 } 2414 else if (TREE_CODE (TREE_TYPE (result_type)) == METHOD_TYPE) 2415 { 2416 if (pedantic || warn_pointer_arith) 2417 pedwarn ("pointer to member function used in arithmetic"); 2418 size_exp = integer_one_node; 2419 } 2420 else 2421 size_exp = size_in_bytes (TREE_TYPE (result_type)); 2422 2423 /* We are manipulating pointer values, so we don't need to warn 2424 about relying on undefined signed overflow. We disable the 2425 warning here because we use integer types so fold won't know that 2426 they are really pointers. */ 2427 fold_defer_overflow_warnings (); 2428 2429 /* If what we are about to multiply by the size of the elements 2430 contains a constant term, apply distributive law 2431 and multiply that constant term separately. 2432 This helps produce common subexpressions. */ 2433 2434 if ((TREE_CODE (intop) == PLUS_EXPR || TREE_CODE (intop) == MINUS_EXPR) 2435 && !TREE_CONSTANT (intop) 2436 && TREE_CONSTANT (TREE_OPERAND (intop, 1)) 2437 && TREE_CONSTANT (size_exp) 2438 /* If the constant comes from pointer subtraction, 2439 skip this optimization--it would cause an error. */ 2440 && TREE_CODE (TREE_TYPE (TREE_OPERAND (intop, 0))) == INTEGER_TYPE 2441 /* If the constant is unsigned, and smaller than the pointer size, 2442 then we must skip this optimization. This is because it could cause 2443 an overflow error if the constant is negative but INTOP is not. */ 2444 && (!TYPE_UNSIGNED (TREE_TYPE (intop)) 2445 || (TYPE_PRECISION (TREE_TYPE (intop)) 2446 == TYPE_PRECISION (TREE_TYPE (ptrop))))) 2447 { 2448 enum tree_code subcode = resultcode; 2449 tree int_type = TREE_TYPE (intop); 2450 if (TREE_CODE (intop) == MINUS_EXPR) 2451 subcode = (subcode == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR); 2452 /* Convert both subexpression types to the type of intop, 2453 because weird cases involving pointer arithmetic 2454 can result in a sum or difference with different type args. */ 2455 ptrop = build_binary_op (subcode, ptrop, 2456 convert (int_type, TREE_OPERAND (intop, 1)), 1); 2457 intop = convert (int_type, TREE_OPERAND (intop, 0)); 2458 } 2459 2460 /* Convert the integer argument to a type the same size as sizetype 2461 so the multiply won't overflow spuriously. */ 2462 2463 if (TYPE_PRECISION (TREE_TYPE (intop)) != TYPE_PRECISION (sizetype) 2464 || TYPE_UNSIGNED (TREE_TYPE (intop)) != TYPE_UNSIGNED (sizetype)) 2465 intop = convert (c_common_type_for_size (TYPE_PRECISION (sizetype), 2466 TYPE_UNSIGNED (sizetype)), intop); 2467 2468 /* Replace the integer argument with a suitable product by the object size. 2469 Do this multiplication as signed, then convert to the appropriate 2470 pointer type (actually unsigned integral). */ 2471 2472 intop = convert (result_type, 2473 build_binary_op (MULT_EXPR, intop, 2474 convert (TREE_TYPE (intop), size_exp), 1)); 2475 2476 /* Create the sum or difference. */ 2477 ret = fold_build2 (resultcode, result_type, ptrop, intop); 2478 2479 fold_undefer_and_ignore_overflow_warnings (); 2480 2481 return ret; 2482} 2483 2484/* Prepare expr to be an argument of a TRUTH_NOT_EXPR, 2485 or for an `if' or `while' statement or ?..: exp. It should already 2486 have been validated to be of suitable type; otherwise, a bad 2487 diagnostic may result. 2488 2489 This preparation consists of taking the ordinary 2490 representation of an expression expr and producing a valid tree 2491 boolean expression describing whether expr is nonzero. We could 2492 simply always do build_binary_op (NE_EXPR, expr, truthvalue_false_node, 1), 2493 but we optimize comparisons, &&, ||, and !. 2494 2495 The resulting type should always be `truthvalue_type_node'. */ 2496 2497tree 2498c_common_truthvalue_conversion (tree expr) 2499{ 2500 switch (TREE_CODE (expr)) 2501 { 2502 case EQ_EXPR: case NE_EXPR: case UNEQ_EXPR: case LTGT_EXPR: 2503 case LE_EXPR: case GE_EXPR: case LT_EXPR: case GT_EXPR: 2504 case UNLE_EXPR: case UNGE_EXPR: case UNLT_EXPR: case UNGT_EXPR: 2505 case ORDERED_EXPR: case UNORDERED_EXPR: 2506 if (TREE_TYPE (expr) == truthvalue_type_node) 2507 return expr; 2508 return build2 (TREE_CODE (expr), truthvalue_type_node, 2509 TREE_OPERAND (expr, 0), TREE_OPERAND (expr, 1)); 2510 2511 case TRUTH_ANDIF_EXPR: 2512 case TRUTH_ORIF_EXPR: 2513 case TRUTH_AND_EXPR: 2514 case TRUTH_OR_EXPR: 2515 case TRUTH_XOR_EXPR: 2516 if (TREE_TYPE (expr) == truthvalue_type_node) 2517 return expr; 2518 return build2 (TREE_CODE (expr), truthvalue_type_node, 2519 c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)), 2520 c_common_truthvalue_conversion (TREE_OPERAND (expr, 1))); 2521 2522 case TRUTH_NOT_EXPR: 2523 if (TREE_TYPE (expr) == truthvalue_type_node) 2524 return expr; 2525 return build1 (TREE_CODE (expr), truthvalue_type_node, 2526 c_common_truthvalue_conversion (TREE_OPERAND (expr, 0))); 2527 2528 case ERROR_MARK: 2529 return expr; 2530 2531 case INTEGER_CST: 2532 /* Avoid integer_zerop to ignore TREE_CONSTANT_OVERFLOW. */ 2533 return (TREE_INT_CST_LOW (expr) != 0 || TREE_INT_CST_HIGH (expr) != 0) 2534 ? truthvalue_true_node 2535 : truthvalue_false_node; 2536 2537 case REAL_CST: 2538 return real_compare (NE_EXPR, &TREE_REAL_CST (expr), &dconst0) 2539 ? truthvalue_true_node 2540 : truthvalue_false_node; 2541 2542 case FUNCTION_DECL: 2543 expr = build_unary_op (ADDR_EXPR, expr, 0); 2544 /* Fall through. */ 2545 2546 case ADDR_EXPR: 2547 { 2548 tree inner = TREE_OPERAND (expr, 0); 2549 if (DECL_P (inner) 2550 && (TREE_CODE (inner) == PARM_DECL 2551 || TREE_CODE (inner) == LABEL_DECL 2552 || !DECL_WEAK (inner))) 2553 { 2554 /* Common Ada/Pascal programmer's mistake. We always warn 2555 about this since it is so bad. */ 2556 warning (OPT_Waddress, 2557 "the address of %qD will always evaluate as %<true%>", 2558 inner); 2559 return truthvalue_true_node; 2560 } 2561 2562 /* If we are taking the address of an external decl, it might be 2563 zero if it is weak, so we cannot optimize. */ 2564 if (DECL_P (inner) 2565 && DECL_EXTERNAL (inner)) 2566 break; 2567 2568 if (TREE_SIDE_EFFECTS (inner)) 2569 return build2 (COMPOUND_EXPR, truthvalue_type_node, 2570 inner, truthvalue_true_node); 2571 else 2572 return truthvalue_true_node; 2573 } 2574 2575 case COMPLEX_EXPR: 2576 return build_binary_op ((TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)) 2577 ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR), 2578 c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)), 2579 c_common_truthvalue_conversion (TREE_OPERAND (expr, 1)), 2580 0); 2581 2582 case NEGATE_EXPR: 2583 case ABS_EXPR: 2584 case FLOAT_EXPR: 2585 /* These don't change whether an object is nonzero or zero. */ 2586 return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)); 2587 2588 case LROTATE_EXPR: 2589 case RROTATE_EXPR: 2590 /* These don't change whether an object is zero or nonzero, but 2591 we can't ignore them if their second arg has side-effects. */ 2592 if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1))) 2593 return build2 (COMPOUND_EXPR, truthvalue_type_node, 2594 TREE_OPERAND (expr, 1), 2595 c_common_truthvalue_conversion (TREE_OPERAND (expr, 0))); 2596 else 2597 return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)); 2598 2599 case COND_EXPR: 2600 /* Distribute the conversion into the arms of a COND_EXPR. */ 2601 return fold_build3 (COND_EXPR, truthvalue_type_node, 2602 TREE_OPERAND (expr, 0), 2603 c_common_truthvalue_conversion (TREE_OPERAND (expr, 1)), 2604 c_common_truthvalue_conversion (TREE_OPERAND (expr, 2))); 2605 2606 case CONVERT_EXPR: 2607 case NOP_EXPR: 2608 /* Don't cancel the effect of a CONVERT_EXPR from a REFERENCE_TYPE, 2609 since that affects how `default_conversion' will behave. */ 2610 if (TREE_CODE (TREE_TYPE (expr)) == REFERENCE_TYPE 2611 || TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == REFERENCE_TYPE) 2612 break; 2613 /* If this is widening the argument, we can ignore it. */ 2614 if (TYPE_PRECISION (TREE_TYPE (expr)) 2615 >= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (expr, 0)))) 2616 return c_common_truthvalue_conversion (TREE_OPERAND (expr, 0)); 2617 break; 2618 2619 case MODIFY_EXPR: 2620 if (!TREE_NO_WARNING (expr) 2621 && warn_parentheses) 2622 { 2623 warning (OPT_Wparentheses, 2624 "suggest parentheses around assignment used as truth value"); 2625 TREE_NO_WARNING (expr) = 1; 2626 } 2627 break; 2628 2629 default: 2630 break; 2631 } 2632 2633 if (TREE_CODE (TREE_TYPE (expr)) == COMPLEX_TYPE) 2634 { 2635 tree t = save_expr (expr); 2636 return (build_binary_op 2637 ((TREE_SIDE_EFFECTS (expr) 2638 ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR), 2639 c_common_truthvalue_conversion (build_unary_op (REALPART_EXPR, t, 0)), 2640 c_common_truthvalue_conversion (build_unary_op (IMAGPART_EXPR, t, 0)), 2641 0)); 2642 } 2643 2644 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1); 2645} 2646 2647static void def_builtin_1 (enum built_in_function fncode, 2648 const char *name, 2649 enum built_in_class fnclass, 2650 tree fntype, tree libtype, 2651 bool both_p, bool fallback_p, bool nonansi_p, 2652 tree fnattrs, bool implicit_p); 2653 2654/* Make a variant type in the proper way for C/C++, propagating qualifiers 2655 down to the element type of an array. */ 2656 2657tree 2658c_build_qualified_type (tree type, int type_quals) 2659{ 2660 if (type == error_mark_node) 2661 return type; 2662 2663 if (TREE_CODE (type) == ARRAY_TYPE) 2664 { 2665 tree t; 2666 tree element_type = c_build_qualified_type (TREE_TYPE (type), 2667 type_quals); 2668 2669 /* See if we already have an identically qualified type. */ 2670 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t)) 2671 { 2672 if (TYPE_QUALS (strip_array_types (t)) == type_quals 2673 && TYPE_NAME (t) == TYPE_NAME (type) 2674 && TYPE_CONTEXT (t) == TYPE_CONTEXT (type) 2675 && attribute_list_equal (TYPE_ATTRIBUTES (t), 2676 TYPE_ATTRIBUTES (type))) 2677 break; 2678 } 2679 if (!t) 2680 { 2681 t = build_variant_type_copy (type); 2682 TREE_TYPE (t) = element_type; 2683 } 2684 return t; 2685 } 2686 2687 /* A restrict-qualified pointer type must be a pointer to object or 2688 incomplete type. Note that the use of POINTER_TYPE_P also allows 2689 REFERENCE_TYPEs, which is appropriate for C++. */ 2690 if ((type_quals & TYPE_QUAL_RESTRICT) 2691 && (!POINTER_TYPE_P (type) 2692 || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (type)))) 2693 { 2694 error ("invalid use of %<restrict%>"); 2695 type_quals &= ~TYPE_QUAL_RESTRICT; 2696 } 2697 2698 return build_qualified_type (type, type_quals); 2699} 2700 2701/* Apply the TYPE_QUALS to the new DECL. */ 2702 2703void 2704c_apply_type_quals_to_decl (int type_quals, tree decl) 2705{ 2706 tree type = TREE_TYPE (decl); 2707 2708 if (type == error_mark_node) 2709 return; 2710 2711 if (((type_quals & TYPE_QUAL_CONST) 2712 || (type && TREE_CODE (type) == REFERENCE_TYPE)) 2713 /* An object declared 'const' is only readonly after it is 2714 initialized. We don't have any way of expressing this currently, 2715 so we need to be conservative and unset TREE_READONLY for types 2716 with constructors. Otherwise aliasing code will ignore stores in 2717 an inline constructor. */ 2718 && !(type && TYPE_NEEDS_CONSTRUCTING (type))) 2719 TREE_READONLY (decl) = 1; 2720 if (type_quals & TYPE_QUAL_VOLATILE) 2721 { 2722 TREE_SIDE_EFFECTS (decl) = 1; 2723 TREE_THIS_VOLATILE (decl) = 1; 2724 } 2725 if (type_quals & TYPE_QUAL_RESTRICT) 2726 { 2727 while (type && TREE_CODE (type) == ARRAY_TYPE) 2728 /* Allow 'restrict' on arrays of pointers. 2729 FIXME currently we just ignore it. */ 2730 type = TREE_TYPE (type); 2731 if (!type 2732 || !POINTER_TYPE_P (type) 2733 || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (type))) 2734 error ("invalid use of %<restrict%>"); 2735 else if (flag_strict_aliasing && type == TREE_TYPE (decl)) 2736 /* Indicate we need to make a unique alias set for this pointer. 2737 We can't do it here because it might be pointing to an 2738 incomplete type. */ 2739 DECL_POINTER_ALIAS_SET (decl) = -2; 2740 } 2741} 2742 2743/* Hash function for the problem of multiple type definitions in 2744 different files. This must hash all types that will compare 2745 equal via comptypes to the same value. In practice it hashes 2746 on some of the simple stuff and leaves the details to comptypes. */ 2747 2748static hashval_t 2749c_type_hash (const void *p) 2750{ 2751 int i = 0; 2752 int shift, size; 2753 tree t = (tree) p; 2754 tree t2; 2755 switch (TREE_CODE (t)) 2756 { 2757 /* For pointers, hash on pointee type plus some swizzling. */ 2758 case POINTER_TYPE: 2759 return c_type_hash (TREE_TYPE (t)) ^ 0x3003003; 2760 /* Hash on number of elements and total size. */ 2761 case ENUMERAL_TYPE: 2762 shift = 3; 2763 t2 = TYPE_VALUES (t); 2764 break; 2765 case RECORD_TYPE: 2766 shift = 0; 2767 t2 = TYPE_FIELDS (t); 2768 break; 2769 case QUAL_UNION_TYPE: 2770 shift = 1; 2771 t2 = TYPE_FIELDS (t); 2772 break; 2773 case UNION_TYPE: 2774 shift = 2; 2775 t2 = TYPE_FIELDS (t); 2776 break; 2777 default: 2778 gcc_unreachable (); 2779 } 2780 for (; t2; t2 = TREE_CHAIN (t2)) 2781 i++; 2782 size = TREE_INT_CST_LOW (TYPE_SIZE (t)); 2783 return ((size << 24) | (i << shift)); 2784} 2785 2786static GTY((param_is (union tree_node))) htab_t type_hash_table; 2787 2788/* Return the typed-based alias set for T, which may be an expression 2789 or a type. Return -1 if we don't do anything special. */ 2790 2791HOST_WIDE_INT 2792c_common_get_alias_set (tree t) 2793{ 2794 tree u; 2795 PTR *slot; 2796 2797 /* Permit type-punning when accessing a union, provided the access 2798 is directly through the union. For example, this code does not 2799 permit taking the address of a union member and then storing 2800 through it. Even the type-punning allowed here is a GCC 2801 extension, albeit a common and useful one; the C standard says 2802 that such accesses have implementation-defined behavior. */ 2803 for (u = t; 2804 TREE_CODE (u) == COMPONENT_REF || TREE_CODE (u) == ARRAY_REF; 2805 u = TREE_OPERAND (u, 0)) 2806 if (TREE_CODE (u) == COMPONENT_REF 2807 && TREE_CODE (TREE_TYPE (TREE_OPERAND (u, 0))) == UNION_TYPE) 2808 return 0; 2809 2810 /* That's all the expressions we handle specially. */ 2811 if (!TYPE_P (t)) 2812 return -1; 2813 2814 /* The C standard guarantees that any object may be accessed via an 2815 lvalue that has character type. */ 2816 if (t == char_type_node 2817 || t == signed_char_type_node 2818 || t == unsigned_char_type_node) 2819 return 0; 2820 2821 /* If it has the may_alias attribute, it can alias anything. */ 2822 if (lookup_attribute ("may_alias", TYPE_ATTRIBUTES (t))) 2823 return 0; 2824 2825 /* The C standard specifically allows aliasing between signed and 2826 unsigned variants of the same type. We treat the signed 2827 variant as canonical. */ 2828 if (TREE_CODE (t) == INTEGER_TYPE && TYPE_UNSIGNED (t)) 2829 { 2830 tree t1 = c_common_signed_type (t); 2831 2832 /* t1 == t can happen for boolean nodes which are always unsigned. */ 2833 if (t1 != t) 2834 return get_alias_set (t1); 2835 } 2836 else if (POINTER_TYPE_P (t)) 2837 { 2838 tree t1; 2839 2840 /* Unfortunately, there is no canonical form of a pointer type. 2841 In particular, if we have `typedef int I', then `int *', and 2842 `I *' are different types. So, we have to pick a canonical 2843 representative. We do this below. 2844 2845 Technically, this approach is actually more conservative that 2846 it needs to be. In particular, `const int *' and `int *' 2847 should be in different alias sets, according to the C and C++ 2848 standard, since their types are not the same, and so, 2849 technically, an `int **' and `const int **' cannot point at 2850 the same thing. 2851 2852 But, the standard is wrong. In particular, this code is 2853 legal C++: 2854 2855 int *ip; 2856 int **ipp = &ip; 2857 const int* const* cipp = ipp; 2858 2859 And, it doesn't make sense for that to be legal unless you 2860 can dereference IPP and CIPP. So, we ignore cv-qualifiers on 2861 the pointed-to types. This issue has been reported to the 2862 C++ committee. */ 2863 t1 = build_type_no_quals (t); 2864 if (t1 != t) 2865 return get_alias_set (t1); 2866 } 2867 2868 /* Handle the case of multiple type nodes referring to "the same" type, 2869 which occurs with IMA. These share an alias set. FIXME: Currently only 2870 C90 is handled. (In C99 type compatibility is not transitive, which 2871 complicates things mightily. The alias set splay trees can theoretically 2872 represent this, but insertion is tricky when you consider all the 2873 different orders things might arrive in.) */ 2874 2875 if (c_language != clk_c || flag_isoc99) 2876 return -1; 2877 2878 /* Save time if there's only one input file. */ 2879 if (num_in_fnames == 1) 2880 return -1; 2881 2882 /* Pointers need special handling if they point to any type that 2883 needs special handling (below). */ 2884 if (TREE_CODE (t) == POINTER_TYPE) 2885 { 2886 tree t2; 2887 /* Find bottom type under any nested POINTERs. */ 2888 for (t2 = TREE_TYPE (t); 2889 TREE_CODE (t2) == POINTER_TYPE; 2890 t2 = TREE_TYPE (t2)) 2891 ; 2892 if (TREE_CODE (t2) != RECORD_TYPE 2893 && TREE_CODE (t2) != ENUMERAL_TYPE 2894 && TREE_CODE (t2) != QUAL_UNION_TYPE 2895 && TREE_CODE (t2) != UNION_TYPE) 2896 return -1; 2897 if (TYPE_SIZE (t2) == 0) 2898 return -1; 2899 } 2900 /* These are the only cases that need special handling. */ 2901 if (TREE_CODE (t) != RECORD_TYPE 2902 && TREE_CODE (t) != ENUMERAL_TYPE 2903 && TREE_CODE (t) != QUAL_UNION_TYPE 2904 && TREE_CODE (t) != UNION_TYPE 2905 && TREE_CODE (t) != POINTER_TYPE) 2906 return -1; 2907 /* Undefined? */ 2908 if (TYPE_SIZE (t) == 0) 2909 return -1; 2910 2911 /* Look up t in hash table. Only one of the compatible types within each 2912 alias set is recorded in the table. */ 2913 if (!type_hash_table) 2914 type_hash_table = htab_create_ggc (1021, c_type_hash, 2915 (htab_eq) lang_hooks.types_compatible_p, 2916 NULL); 2917 slot = htab_find_slot (type_hash_table, t, INSERT); 2918 if (*slot != NULL) 2919 { 2920 TYPE_ALIAS_SET (t) = TYPE_ALIAS_SET ((tree)*slot); 2921 return TYPE_ALIAS_SET ((tree)*slot); 2922 } 2923 else 2924 /* Our caller will assign and record (in t) a new alias set; all we need 2925 to do is remember t in the hash table. */ 2926 *slot = t; 2927 2928 return -1; 2929} 2930 2931/* Compute the value of 'sizeof (TYPE)' or '__alignof__ (TYPE)', where the 2932 second parameter indicates which OPERATOR is being applied. The COMPLAIN 2933 flag controls whether we should diagnose possibly ill-formed 2934 constructs or not. */ 2935 2936tree 2937c_sizeof_or_alignof_type (tree type, bool is_sizeof, int complain) 2938{ 2939 const char *op_name; 2940 tree value = NULL; 2941 enum tree_code type_code = TREE_CODE (type); 2942 2943 op_name = is_sizeof ? "sizeof" : "__alignof__"; 2944 2945 if (type_code == FUNCTION_TYPE) 2946 { 2947 if (is_sizeof) 2948 { 2949 if (complain && (pedantic || warn_pointer_arith)) 2950 pedwarn ("invalid application of %<sizeof%> to a function type"); 2951 value = size_one_node; 2952 } 2953 else 2954 value = size_int (FUNCTION_BOUNDARY / BITS_PER_UNIT); 2955 } 2956 else if (type_code == VOID_TYPE || type_code == ERROR_MARK) 2957 { 2958 if (type_code == VOID_TYPE 2959 && complain && (pedantic || warn_pointer_arith)) 2960 pedwarn ("invalid application of %qs to a void type", op_name); 2961 value = size_one_node; 2962 } 2963 else if (!COMPLETE_TYPE_P (type)) 2964 { 2965 if (complain) 2966 error ("invalid application of %qs to incomplete type %qT ", 2967 op_name, type); 2968 value = size_zero_node; 2969 } 2970 else 2971 { 2972 if (is_sizeof) 2973 /* Convert in case a char is more than one unit. */ 2974 value = size_binop (CEIL_DIV_EXPR, TYPE_SIZE_UNIT (type), 2975 size_int (TYPE_PRECISION (char_type_node) 2976 / BITS_PER_UNIT)); 2977 else 2978 value = size_int (TYPE_ALIGN_UNIT (type)); 2979 } 2980 2981 /* VALUE will have an integer type with TYPE_IS_SIZETYPE set. 2982 TYPE_IS_SIZETYPE means that certain things (like overflow) will 2983 never happen. However, this node should really have type 2984 `size_t', which is just a typedef for an ordinary integer type. */ 2985 value = fold_convert (size_type_node, value); 2986 gcc_assert (!TYPE_IS_SIZETYPE (TREE_TYPE (value))); 2987 2988 return value; 2989} 2990 2991/* Implement the __alignof keyword: Return the minimum required 2992 alignment of EXPR, measured in bytes. For VAR_DECL's and 2993 FIELD_DECL's return DECL_ALIGN (which can be set from an 2994 "aligned" __attribute__ specification). */ 2995 2996tree 2997c_alignof_expr (tree expr) 2998{ 2999 tree t; 3000 3001 if (TREE_CODE (expr) == VAR_DECL) 3002 t = size_int (DECL_ALIGN_UNIT (expr)); 3003 3004 else if (TREE_CODE (expr) == COMPONENT_REF 3005 && DECL_C_BIT_FIELD (TREE_OPERAND (expr, 1))) 3006 { 3007 error ("%<__alignof%> applied to a bit-field"); 3008 t = size_one_node; 3009 } 3010 else if (TREE_CODE (expr) == COMPONENT_REF 3011 && TREE_CODE (TREE_OPERAND (expr, 1)) == FIELD_DECL) 3012 t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (expr, 1))); 3013 3014 else if (TREE_CODE (expr) == INDIRECT_REF) 3015 { 3016 tree t = TREE_OPERAND (expr, 0); 3017 tree best = t; 3018 int bestalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t))); 3019 3020 while ((TREE_CODE (t) == NOP_EXPR || TREE_CODE (t) == CONVERT_EXPR) 3021 && TREE_CODE (TREE_TYPE (TREE_OPERAND (t, 0))) == POINTER_TYPE) 3022 { 3023 int thisalign; 3024 3025 t = TREE_OPERAND (t, 0); 3026 thisalign = TYPE_ALIGN (TREE_TYPE (TREE_TYPE (t))); 3027 if (thisalign > bestalign) 3028 best = t, bestalign = thisalign; 3029 } 3030 return c_alignof (TREE_TYPE (TREE_TYPE (best))); 3031 } 3032 else 3033 return c_alignof (TREE_TYPE (expr)); 3034 3035 return fold_convert (size_type_node, t); 3036} 3037 3038/* Handle C and C++ default attributes. */ 3039 3040enum built_in_attribute 3041{ 3042#define DEF_ATTR_NULL_TREE(ENUM) ENUM, 3043#define DEF_ATTR_INT(ENUM, VALUE) ENUM, 3044#define DEF_ATTR_IDENT(ENUM, STRING) ENUM, 3045#define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) ENUM, 3046#include "builtin-attrs.def" 3047#undef DEF_ATTR_NULL_TREE 3048#undef DEF_ATTR_INT 3049#undef DEF_ATTR_IDENT 3050#undef DEF_ATTR_TREE_LIST 3051 ATTR_LAST 3052}; 3053 3054static GTY(()) tree built_in_attributes[(int) ATTR_LAST]; 3055 3056static void c_init_attributes (void); 3057 3058enum c_builtin_type 3059{ 3060#define DEF_PRIMITIVE_TYPE(NAME, VALUE) NAME, 3061#define DEF_FUNCTION_TYPE_0(NAME, RETURN) NAME, 3062#define DEF_FUNCTION_TYPE_1(NAME, RETURN, ARG1) NAME, 3063#define DEF_FUNCTION_TYPE_2(NAME, RETURN, ARG1, ARG2) NAME, 3064#define DEF_FUNCTION_TYPE_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME, 3065#define DEF_FUNCTION_TYPE_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME, 3066#define DEF_FUNCTION_TYPE_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) NAME, 3067#define DEF_FUNCTION_TYPE_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6) NAME, 3068#define DEF_FUNCTION_TYPE_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7) NAME, 3069#define DEF_FUNCTION_TYPE_VAR_0(NAME, RETURN) NAME, 3070#define DEF_FUNCTION_TYPE_VAR_1(NAME, RETURN, ARG1) NAME, 3071#define DEF_FUNCTION_TYPE_VAR_2(NAME, RETURN, ARG1, ARG2) NAME, 3072#define DEF_FUNCTION_TYPE_VAR_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME, 3073#define DEF_FUNCTION_TYPE_VAR_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME, 3074#define DEF_FUNCTION_TYPE_VAR_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG6) \ 3075 NAME, 3076#define DEF_POINTER_TYPE(NAME, TYPE) NAME, 3077#include "builtin-types.def" 3078#undef DEF_PRIMITIVE_TYPE 3079#undef DEF_FUNCTION_TYPE_0 3080#undef DEF_FUNCTION_TYPE_1 3081#undef DEF_FUNCTION_TYPE_2 3082#undef DEF_FUNCTION_TYPE_3 3083#undef DEF_FUNCTION_TYPE_4 3084#undef DEF_FUNCTION_TYPE_5 3085#undef DEF_FUNCTION_TYPE_6 3086#undef DEF_FUNCTION_TYPE_7 3087#undef DEF_FUNCTION_TYPE_VAR_0 3088#undef DEF_FUNCTION_TYPE_VAR_1 3089#undef DEF_FUNCTION_TYPE_VAR_2 3090#undef DEF_FUNCTION_TYPE_VAR_3 3091#undef DEF_FUNCTION_TYPE_VAR_4 3092#undef DEF_FUNCTION_TYPE_VAR_5 3093#undef DEF_POINTER_TYPE 3094 BT_LAST 3095}; 3096 3097typedef enum c_builtin_type builtin_type; 3098 3099/* A temporary array for c_common_nodes_and_builtins. Used in 3100 communication with def_fn_type. */ 3101static tree builtin_types[(int) BT_LAST + 1]; 3102 3103/* A helper function for c_common_nodes_and_builtins. Build function type 3104 for DEF with return type RET and N arguments. If VAR is true, then the 3105 function should be variadic after those N arguments. 3106 3107 Takes special care not to ICE if any of the types involved are 3108 error_mark_node, which indicates that said type is not in fact available 3109 (see builtin_type_for_size). In which case the function type as a whole 3110 should be error_mark_node. */ 3111 3112static void 3113def_fn_type (builtin_type def, builtin_type ret, bool var, int n, ...) 3114{ 3115 tree args = NULL, t; 3116 va_list list; 3117 int i; 3118 3119 va_start (list, n); 3120 for (i = 0; i < n; ++i) 3121 { 3122 builtin_type a = va_arg (list, builtin_type); 3123 t = builtin_types[a]; 3124 if (t == error_mark_node) 3125 goto egress; 3126 args = tree_cons (NULL_TREE, t, args); 3127 } 3128 va_end (list); 3129 3130 args = nreverse (args); 3131 if (!var) 3132 args = chainon (args, void_list_node); 3133 3134 t = builtin_types[ret]; 3135 if (t == error_mark_node) 3136 goto egress; 3137 t = build_function_type (t, args); 3138 3139 egress: 3140 builtin_types[def] = t; 3141} 3142 3143/* Build builtin functions common to both C and C++ language 3144 frontends. */ 3145 3146static void 3147c_define_builtins (tree va_list_ref_type_node, tree va_list_arg_type_node) 3148{ 3149#define DEF_PRIMITIVE_TYPE(ENUM, VALUE) \ 3150 builtin_types[ENUM] = VALUE; 3151#define DEF_FUNCTION_TYPE_0(ENUM, RETURN) \ 3152 def_fn_type (ENUM, RETURN, 0, 0); 3153#define DEF_FUNCTION_TYPE_1(ENUM, RETURN, ARG1) \ 3154 def_fn_type (ENUM, RETURN, 0, 1, ARG1); 3155#define DEF_FUNCTION_TYPE_2(ENUM, RETURN, ARG1, ARG2) \ 3156 def_fn_type (ENUM, RETURN, 0, 2, ARG1, ARG2); 3157#define DEF_FUNCTION_TYPE_3(ENUM, RETURN, ARG1, ARG2, ARG3) \ 3158 def_fn_type (ENUM, RETURN, 0, 3, ARG1, ARG2, ARG3); 3159#define DEF_FUNCTION_TYPE_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \ 3160 def_fn_type (ENUM, RETURN, 0, 4, ARG1, ARG2, ARG3, ARG4); 3161#define DEF_FUNCTION_TYPE_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \ 3162 def_fn_type (ENUM, RETURN, 0, 5, ARG1, ARG2, ARG3, ARG4, ARG5); 3163#define DEF_FUNCTION_TYPE_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \ 3164 ARG6) \ 3165 def_fn_type (ENUM, RETURN, 0, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6); 3166#define DEF_FUNCTION_TYPE_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \ 3167 ARG6, ARG7) \ 3168 def_fn_type (ENUM, RETURN, 0, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7); 3169#define DEF_FUNCTION_TYPE_VAR_0(ENUM, RETURN) \ 3170 def_fn_type (ENUM, RETURN, 1, 0); 3171#define DEF_FUNCTION_TYPE_VAR_1(ENUM, RETURN, ARG1) \ 3172 def_fn_type (ENUM, RETURN, 1, 1, ARG1); 3173#define DEF_FUNCTION_TYPE_VAR_2(ENUM, RETURN, ARG1, ARG2) \ 3174 def_fn_type (ENUM, RETURN, 1, 2, ARG1, ARG2); 3175#define DEF_FUNCTION_TYPE_VAR_3(ENUM, RETURN, ARG1, ARG2, ARG3) \ 3176 def_fn_type (ENUM, RETURN, 1, 3, ARG1, ARG2, ARG3); 3177#define DEF_FUNCTION_TYPE_VAR_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \ 3178 def_fn_type (ENUM, RETURN, 1, 4, ARG1, ARG2, ARG3, ARG4); 3179#define DEF_FUNCTION_TYPE_VAR_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \ 3180 def_fn_type (ENUM, RETURN, 1, 5, ARG1, ARG2, ARG3, ARG4, ARG5); 3181#define DEF_POINTER_TYPE(ENUM, TYPE) \ 3182 builtin_types[(int) ENUM] = build_pointer_type (builtin_types[(int) TYPE]); 3183 3184#include "builtin-types.def" 3185 3186#undef DEF_PRIMITIVE_TYPE 3187#undef DEF_FUNCTION_TYPE_1 3188#undef DEF_FUNCTION_TYPE_2 3189#undef DEF_FUNCTION_TYPE_3 3190#undef DEF_FUNCTION_TYPE_4 3191#undef DEF_FUNCTION_TYPE_5 3192#undef DEF_FUNCTION_TYPE_6 3193#undef DEF_FUNCTION_TYPE_VAR_0 3194#undef DEF_FUNCTION_TYPE_VAR_1 3195#undef DEF_FUNCTION_TYPE_VAR_2 3196#undef DEF_FUNCTION_TYPE_VAR_3 3197#undef DEF_FUNCTION_TYPE_VAR_4 3198#undef DEF_FUNCTION_TYPE_VAR_5 3199#undef DEF_POINTER_TYPE 3200 builtin_types[(int) BT_LAST] = NULL_TREE; 3201 3202 c_init_attributes (); 3203 3204#define DEF_BUILTIN(ENUM, NAME, CLASS, TYPE, LIBTYPE, BOTH_P, FALLBACK_P, \ 3205 NONANSI_P, ATTRS, IMPLICIT, COND) \ 3206 if (NAME && COND) \ 3207 def_builtin_1 (ENUM, NAME, CLASS, \ 3208 builtin_types[(int) TYPE], \ 3209 builtin_types[(int) LIBTYPE], \ 3210 BOTH_P, FALLBACK_P, NONANSI_P, \ 3211 built_in_attributes[(int) ATTRS], IMPLICIT); 3212#include "builtins.def" 3213#undef DEF_BUILTIN 3214 3215 build_common_builtin_nodes (); 3216 3217 targetm.init_builtins (); 3218 if (flag_mudflap) 3219 mudflap_init (); 3220} 3221 3222/* Build tree nodes and builtin functions common to both C and C++ language 3223 frontends. */ 3224 3225void 3226c_common_nodes_and_builtins (void) 3227{ 3228 int wchar_type_size; 3229 tree array_domain_type; 3230 tree va_list_ref_type_node; 3231 tree va_list_arg_type_node; 3232 3233 /* Define `int' and `char' first so that dbx will output them first. */ 3234 record_builtin_type (RID_INT, NULL, integer_type_node); 3235 record_builtin_type (RID_CHAR, "char", char_type_node); 3236 3237 /* `signed' is the same as `int'. FIXME: the declarations of "signed", 3238 "unsigned long", "long long unsigned" and "unsigned short" were in C++ 3239 but not C. Are the conditionals here needed? */ 3240 if (c_dialect_cxx ()) 3241 record_builtin_type (RID_SIGNED, NULL, integer_type_node); 3242 record_builtin_type (RID_LONG, "long int", long_integer_type_node); 3243 record_builtin_type (RID_UNSIGNED, "unsigned int", unsigned_type_node); 3244 record_builtin_type (RID_MAX, "long unsigned int", 3245 long_unsigned_type_node); 3246 if (c_dialect_cxx ()) 3247 record_builtin_type (RID_MAX, "unsigned long", long_unsigned_type_node); 3248 record_builtin_type (RID_MAX, "long long int", 3249 long_long_integer_type_node); 3250 record_builtin_type (RID_MAX, "long long unsigned int", 3251 long_long_unsigned_type_node); 3252 if (c_dialect_cxx ()) 3253 record_builtin_type (RID_MAX, "long long unsigned", 3254 long_long_unsigned_type_node); 3255 record_builtin_type (RID_SHORT, "short int", short_integer_type_node); 3256 record_builtin_type (RID_MAX, "short unsigned int", 3257 short_unsigned_type_node); 3258 if (c_dialect_cxx ()) 3259 record_builtin_type (RID_MAX, "unsigned short", 3260 short_unsigned_type_node); 3261 3262 /* Define both `signed char' and `unsigned char'. */ 3263 record_builtin_type (RID_MAX, "signed char", signed_char_type_node); 3264 record_builtin_type (RID_MAX, "unsigned char", unsigned_char_type_node); 3265 3266 /* These are types that c_common_type_for_size and 3267 c_common_type_for_mode use. */ 3268 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE, 3269 intQI_type_node)); 3270 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE, 3271 intHI_type_node)); 3272 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE, 3273 intSI_type_node)); 3274 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE, 3275 intDI_type_node)); 3276#if HOST_BITS_PER_WIDE_INT >= 64 3277 if (targetm.scalar_mode_supported_p (TImode)) 3278 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, 3279 get_identifier ("__int128_t"), 3280 intTI_type_node)); 3281#endif 3282 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE, 3283 unsigned_intQI_type_node)); 3284 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE, 3285 unsigned_intHI_type_node)); 3286 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE, 3287 unsigned_intSI_type_node)); 3288 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE, 3289 unsigned_intDI_type_node)); 3290#if HOST_BITS_PER_WIDE_INT >= 64 3291 if (targetm.scalar_mode_supported_p (TImode)) 3292 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, 3293 get_identifier ("__uint128_t"), 3294 unsigned_intTI_type_node)); 3295#endif 3296 3297 /* Create the widest literal types. */ 3298 widest_integer_literal_type_node 3299 = make_signed_type (HOST_BITS_PER_WIDE_INT * 2); 3300 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE, 3301 widest_integer_literal_type_node)); 3302 3303 widest_unsigned_literal_type_node 3304 = make_unsigned_type (HOST_BITS_PER_WIDE_INT * 2); 3305 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, NULL_TREE, 3306 widest_unsigned_literal_type_node)); 3307 3308 /* `unsigned long' is the standard type for sizeof. 3309 Note that stddef.h uses `unsigned long', 3310 and this must agree, even if long and int are the same size. */ 3311 size_type_node = 3312 TREE_TYPE (identifier_global_value (get_identifier (SIZE_TYPE))); 3313 signed_size_type_node = c_common_signed_type (size_type_node); 3314 set_sizetype (size_type_node); 3315 3316 pid_type_node = 3317 TREE_TYPE (identifier_global_value (get_identifier (PID_TYPE))); 3318 3319 build_common_tree_nodes_2 (flag_short_double); 3320 3321 record_builtin_type (RID_FLOAT, NULL, float_type_node); 3322 record_builtin_type (RID_DOUBLE, NULL, double_type_node); 3323 record_builtin_type (RID_MAX, "long double", long_double_type_node); 3324 3325 /* Only supported decimal floating point extension if the target 3326 actually supports underlying modes. */ 3327 if (targetm.scalar_mode_supported_p (SDmode) 3328 && targetm.scalar_mode_supported_p (DDmode) 3329 && targetm.scalar_mode_supported_p (TDmode)) 3330 { 3331 record_builtin_type (RID_DFLOAT32, NULL, dfloat32_type_node); 3332 record_builtin_type (RID_DFLOAT64, NULL, dfloat64_type_node); 3333 record_builtin_type (RID_DFLOAT128, NULL, dfloat128_type_node); 3334 } 3335 3336 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, 3337 get_identifier ("complex int"), 3338 complex_integer_type_node)); 3339 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, 3340 get_identifier ("complex float"), 3341 complex_float_type_node)); 3342 lang_hooks.decls.pushdecl (build_decl (TYPE_DECL, 3343 get_identifier ("complex double"), 3344 complex_double_type_node)); 3345 lang_hooks.decls.pushdecl 3346 (build_decl (TYPE_DECL, get_identifier ("complex long double"), 3347 complex_long_double_type_node)); 3348 3349 if (c_dialect_cxx ()) 3350 /* For C++, make fileptr_type_node a distinct void * type until 3351 FILE type is defined. */ 3352 fileptr_type_node = build_variant_type_copy (ptr_type_node); 3353 3354 record_builtin_type (RID_VOID, NULL, void_type_node); 3355 3356 /* This node must not be shared. */ 3357 void_zero_node = make_node (INTEGER_CST); 3358 TREE_TYPE (void_zero_node) = void_type_node; 3359 3360 void_list_node = build_void_list_node (); 3361 3362 /* Make a type to be the domain of a few array types 3363 whose domains don't really matter. 3364 200 is small enough that it always fits in size_t 3365 and large enough that it can hold most function names for the 3366 initializations of __FUNCTION__ and __PRETTY_FUNCTION__. */ 3367 array_domain_type = build_index_type (size_int (200)); 3368 3369 /* Make a type for arrays of characters. 3370 With luck nothing will ever really depend on the length of this 3371 array type. */ 3372 char_array_type_node 3373 = build_array_type (char_type_node, array_domain_type); 3374 3375 /* Likewise for arrays of ints. */ 3376 int_array_type_node 3377 = build_array_type (integer_type_node, array_domain_type); 3378 3379 string_type_node = build_pointer_type (char_type_node); 3380 const_string_type_node 3381 = build_pointer_type (build_qualified_type 3382 (char_type_node, TYPE_QUAL_CONST)); 3383 3384 /* This is special for C++ so functions can be overloaded. */ 3385 wchar_type_node = get_identifier (MODIFIED_WCHAR_TYPE); 3386 wchar_type_node = TREE_TYPE (identifier_global_value (wchar_type_node)); 3387 wchar_type_size = TYPE_PRECISION (wchar_type_node); 3388 if (c_dialect_cxx ()) 3389 { 3390 if (TYPE_UNSIGNED (wchar_type_node)) 3391 wchar_type_node = make_unsigned_type (wchar_type_size); 3392 else 3393 wchar_type_node = make_signed_type (wchar_type_size); 3394 record_builtin_type (RID_WCHAR, "wchar_t", wchar_type_node); 3395 } 3396 else 3397 { 3398 signed_wchar_type_node = c_common_signed_type (wchar_type_node); 3399 unsigned_wchar_type_node = c_common_unsigned_type (wchar_type_node); 3400 } 3401 3402 /* This is for wide string constants. */ 3403 wchar_array_type_node 3404 = build_array_type (wchar_type_node, array_domain_type); 3405 3406 wint_type_node = 3407 TREE_TYPE (identifier_global_value (get_identifier (WINT_TYPE))); 3408 3409 intmax_type_node = 3410 TREE_TYPE (identifier_global_value (get_identifier (INTMAX_TYPE))); 3411 uintmax_type_node = 3412 TREE_TYPE (identifier_global_value (get_identifier (UINTMAX_TYPE))); 3413 3414 default_function_type = build_function_type (integer_type_node, NULL_TREE); 3415 ptrdiff_type_node 3416 = TREE_TYPE (identifier_global_value (get_identifier (PTRDIFF_TYPE))); 3417 unsigned_ptrdiff_type_node = c_common_unsigned_type (ptrdiff_type_node); 3418 3419 lang_hooks.decls.pushdecl 3420 (build_decl (TYPE_DECL, get_identifier ("__builtin_va_list"), 3421 va_list_type_node)); 3422 3423 if (TREE_CODE (va_list_type_node) == ARRAY_TYPE) 3424 { 3425 va_list_arg_type_node = va_list_ref_type_node = 3426 build_pointer_type (TREE_TYPE (va_list_type_node)); 3427 } 3428 else 3429 { 3430 va_list_arg_type_node = va_list_type_node; 3431 va_list_ref_type_node = build_reference_type (va_list_type_node); 3432 } 3433 3434 if (!flag_preprocess_only) 3435 c_define_builtins (va_list_ref_type_node, va_list_arg_type_node); 3436 3437 main_identifier_node = get_identifier ("main"); 3438 3439 /* Create the built-in __null node. It is important that this is 3440 not shared. */ 3441 null_node = make_node (INTEGER_CST); 3442 TREE_TYPE (null_node) = c_common_type_for_size (POINTER_SIZE, 0); 3443 3444 /* Since builtin_types isn't gc'ed, don't export these nodes. */ 3445 memset (builtin_types, 0, sizeof (builtin_types)); 3446} 3447 3448/* Look up the function in built_in_decls that corresponds to DECL 3449 and set ASMSPEC as its user assembler name. DECL must be a 3450 function decl that declares a builtin. */ 3451 3452void 3453set_builtin_user_assembler_name (tree decl, const char *asmspec) 3454{ 3455 tree builtin; 3456 gcc_assert (TREE_CODE (decl) == FUNCTION_DECL 3457 && DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL 3458 && asmspec != 0); 3459 3460 builtin = built_in_decls [DECL_FUNCTION_CODE (decl)]; 3461 set_user_assembler_name (builtin, asmspec); 3462 if (DECL_FUNCTION_CODE (decl) == BUILT_IN_MEMCPY) 3463 init_block_move_fn (asmspec); 3464 else if (DECL_FUNCTION_CODE (decl) == BUILT_IN_MEMSET) 3465 init_block_clear_fn (asmspec); 3466} 3467 3468/* The number of named compound-literals generated thus far. */ 3469static GTY(()) int compound_literal_number; 3470 3471/* Set DECL_NAME for DECL, a VAR_DECL for a compound-literal. */ 3472 3473void 3474set_compound_literal_name (tree decl) 3475{ 3476 char *name; 3477 ASM_FORMAT_PRIVATE_NAME (name, "__compound_literal", 3478 compound_literal_number); 3479 compound_literal_number++; 3480 DECL_NAME (decl) = get_identifier (name); 3481} 3482 3483tree 3484build_va_arg (tree expr, tree type) 3485{ 3486 return build1 (VA_ARG_EXPR, type, expr); 3487} 3488 3489 3490/* Linked list of disabled built-in functions. */ 3491 3492typedef struct disabled_builtin 3493{ 3494 const char *name; 3495 struct disabled_builtin *next; 3496} disabled_builtin; 3497static disabled_builtin *disabled_builtins = NULL; 3498 3499static bool builtin_function_disabled_p (const char *); 3500 3501/* Disable a built-in function specified by -fno-builtin-NAME. If NAME 3502 begins with "__builtin_", give an error. */ 3503 3504void 3505disable_builtin_function (const char *name) 3506{ 3507 if (strncmp (name, "__builtin_", strlen ("__builtin_")) == 0) 3508 error ("cannot disable built-in function %qs", name); 3509 else 3510 { 3511 disabled_builtin *new_disabled_builtin = XNEW (disabled_builtin); 3512 new_disabled_builtin->name = name; 3513 new_disabled_builtin->next = disabled_builtins; 3514 disabled_builtins = new_disabled_builtin; 3515 } 3516} 3517 3518 3519/* Return true if the built-in function NAME has been disabled, false 3520 otherwise. */ 3521 3522static bool 3523builtin_function_disabled_p (const char *name) 3524{ 3525 disabled_builtin *p; 3526 for (p = disabled_builtins; p != NULL; p = p->next) 3527 { 3528 if (strcmp (name, p->name) == 0) 3529 return true; 3530 } 3531 return false; 3532} 3533 3534 3535/* Worker for DEF_BUILTIN. 3536 Possibly define a builtin function with one or two names. 3537 Does not declare a non-__builtin_ function if flag_no_builtin, or if 3538 nonansi_p and flag_no_nonansi_builtin. */ 3539 3540static void 3541def_builtin_1 (enum built_in_function fncode, 3542 const char *name, 3543 enum built_in_class fnclass, 3544 tree fntype, tree libtype, 3545 bool both_p, bool fallback_p, bool nonansi_p, 3546 tree fnattrs, bool implicit_p) 3547{ 3548 tree decl; 3549 const char *libname; 3550 3551 if (fntype == error_mark_node) 3552 return; 3553 3554 gcc_assert ((!both_p && !fallback_p) 3555 || !strncmp (name, "__builtin_", 3556 strlen ("__builtin_"))); 3557 3558 libname = name + strlen ("__builtin_"); 3559 decl = lang_hooks.builtin_function (name, fntype, fncode, fnclass, 3560 (fallback_p ? libname : NULL), 3561 fnattrs); 3562 if (both_p 3563 && !flag_no_builtin && !builtin_function_disabled_p (libname) 3564 && !(nonansi_p && flag_no_nonansi_builtin)) 3565 lang_hooks.builtin_function (libname, libtype, fncode, fnclass, 3566 NULL, fnattrs); 3567 3568 built_in_decls[(int) fncode] = decl; 3569 if (implicit_p) 3570 implicit_built_in_decls[(int) fncode] = decl; 3571} 3572 3573/* Nonzero if the type T promotes to int. This is (nearly) the 3574 integral promotions defined in ISO C99 6.3.1.1/2. */ 3575 3576bool 3577c_promoting_integer_type_p (tree t) 3578{ 3579 switch (TREE_CODE (t)) 3580 { 3581 case INTEGER_TYPE: 3582 return (TYPE_MAIN_VARIANT (t) == char_type_node 3583 || TYPE_MAIN_VARIANT (t) == signed_char_type_node 3584 || TYPE_MAIN_VARIANT (t) == unsigned_char_type_node 3585 || TYPE_MAIN_VARIANT (t) == short_integer_type_node 3586 || TYPE_MAIN_VARIANT (t) == short_unsigned_type_node 3587 || TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node)); 3588 3589 case ENUMERAL_TYPE: 3590 /* ??? Technically all enumerations not larger than an int 3591 promote to an int. But this is used along code paths 3592 that only want to notice a size change. */ 3593 return TYPE_PRECISION (t) < TYPE_PRECISION (integer_type_node); 3594 3595 case BOOLEAN_TYPE: 3596 return 1; 3597 3598 default: 3599 return 0; 3600 } 3601} 3602 3603/* Return 1 if PARMS specifies a fixed number of parameters 3604 and none of their types is affected by default promotions. */ 3605 3606int 3607self_promoting_args_p (tree parms) 3608{ 3609 tree t; 3610 for (t = parms; t; t = TREE_CHAIN (t)) 3611 { 3612 tree type = TREE_VALUE (t); 3613 3614 if (type == error_mark_node) 3615 continue; 3616 3617 if (TREE_CHAIN (t) == 0 && type != void_type_node) 3618 return 0; 3619 3620 if (type == 0) 3621 return 0; 3622 3623 if (TYPE_MAIN_VARIANT (type) == float_type_node) 3624 return 0; 3625 3626 if (c_promoting_integer_type_p (type)) 3627 return 0; 3628 } 3629 return 1; 3630} 3631 3632/* Recursively examines the array elements of TYPE, until a non-array 3633 element type is found. */ 3634 3635tree 3636strip_array_types (tree type) 3637{ 3638 while (TREE_CODE (type) == ARRAY_TYPE) 3639 type = TREE_TYPE (type); 3640 3641 return type; 3642} 3643 3644/* Recursively remove any '*' or '&' operator from TYPE. */ 3645tree 3646strip_pointer_operator (tree t) 3647{ 3648 while (POINTER_TYPE_P (t)) 3649 t = TREE_TYPE (t); 3650 return t; 3651} 3652 3653/* Used to compare case labels. K1 and K2 are actually tree nodes 3654 representing case labels, or NULL_TREE for a `default' label. 3655 Returns -1 if K1 is ordered before K2, -1 if K1 is ordered after 3656 K2, and 0 if K1 and K2 are equal. */ 3657 3658int 3659case_compare (splay_tree_key k1, splay_tree_key k2) 3660{ 3661 /* Consider a NULL key (such as arises with a `default' label) to be 3662 smaller than anything else. */ 3663 if (!k1) 3664 return k2 ? -1 : 0; 3665 else if (!k2) 3666 return k1 ? 1 : 0; 3667 3668 return tree_int_cst_compare ((tree) k1, (tree) k2); 3669} 3670 3671/* Process a case label for the range LOW_VALUE ... HIGH_VALUE. If 3672 LOW_VALUE and HIGH_VALUE are both NULL_TREE then this case label is 3673 actually a `default' label. If only HIGH_VALUE is NULL_TREE, then 3674 case label was declared using the usual C/C++ syntax, rather than 3675 the GNU case range extension. CASES is a tree containing all the 3676 case ranges processed so far; COND is the condition for the 3677 switch-statement itself. Returns the CASE_LABEL_EXPR created, or 3678 ERROR_MARK_NODE if no CASE_LABEL_EXPR is created. */ 3679 3680tree 3681c_add_case_label (splay_tree cases, tree cond, tree orig_type, 3682 tree low_value, tree high_value) 3683{ 3684 tree type; 3685 tree label; 3686 tree case_label; 3687 splay_tree_node node; 3688 3689 /* Create the LABEL_DECL itself. */ 3690 label = create_artificial_label (); 3691 3692 /* If there was an error processing the switch condition, bail now 3693 before we get more confused. */ 3694 if (!cond || cond == error_mark_node) 3695 goto error_out; 3696 3697 if ((low_value && TREE_TYPE (low_value) 3698 && POINTER_TYPE_P (TREE_TYPE (low_value))) 3699 || (high_value && TREE_TYPE (high_value) 3700 && POINTER_TYPE_P (TREE_TYPE (high_value)))) 3701 { 3702 error ("pointers are not permitted as case values"); 3703 goto error_out; 3704 } 3705 3706 /* Case ranges are a GNU extension. */ 3707 if (high_value && pedantic) 3708 pedwarn ("range expressions in switch statements are non-standard"); 3709 3710 type = TREE_TYPE (cond); 3711 if (low_value) 3712 { 3713 low_value = check_case_value (low_value); 3714 low_value = convert_and_check (type, low_value); 3715 if (low_value == error_mark_node) 3716 goto error_out; 3717 } 3718 if (high_value) 3719 { 3720 high_value = check_case_value (high_value); 3721 high_value = convert_and_check (type, high_value); 3722 if (high_value == error_mark_node) 3723 goto error_out; 3724 } 3725 3726 if (low_value && high_value) 3727 { 3728 /* If the LOW_VALUE and HIGH_VALUE are the same, then this isn't 3729 really a case range, even though it was written that way. 3730 Remove the HIGH_VALUE to simplify later processing. */ 3731 if (tree_int_cst_equal (low_value, high_value)) 3732 high_value = NULL_TREE; 3733 else if (!tree_int_cst_lt (low_value, high_value)) 3734 warning (0, "empty range specified"); 3735 } 3736 3737 /* See if the case is in range of the type of the original testing 3738 expression. If both low_value and high_value are out of range, 3739 don't insert the case label and return NULL_TREE. */ 3740 if (low_value 3741 && !check_case_bounds (type, orig_type, 3742 &low_value, high_value ? &high_value : NULL)) 3743 return NULL_TREE; 3744 3745 /* Look up the LOW_VALUE in the table of case labels we already 3746 have. */ 3747 node = splay_tree_lookup (cases, (splay_tree_key) low_value); 3748 /* If there was not an exact match, check for overlapping ranges. 3749 There's no need to do this if there's no LOW_VALUE or HIGH_VALUE; 3750 that's a `default' label and the only overlap is an exact match. */ 3751 if (!node && (low_value || high_value)) 3752 { 3753 splay_tree_node low_bound; 3754 splay_tree_node high_bound; 3755 3756 /* Even though there wasn't an exact match, there might be an 3757 overlap between this case range and another case range. 3758 Since we've (inductively) not allowed any overlapping case 3759 ranges, we simply need to find the greatest low case label 3760 that is smaller that LOW_VALUE, and the smallest low case 3761 label that is greater than LOW_VALUE. If there is an overlap 3762 it will occur in one of these two ranges. */ 3763 low_bound = splay_tree_predecessor (cases, 3764 (splay_tree_key) low_value); 3765 high_bound = splay_tree_successor (cases, 3766 (splay_tree_key) low_value); 3767 3768 /* Check to see if the LOW_BOUND overlaps. It is smaller than 3769 the LOW_VALUE, so there is no need to check unless the 3770 LOW_BOUND is in fact itself a case range. */ 3771 if (low_bound 3772 && CASE_HIGH ((tree) low_bound->value) 3773 && tree_int_cst_compare (CASE_HIGH ((tree) low_bound->value), 3774 low_value) >= 0) 3775 node = low_bound; 3776 /* Check to see if the HIGH_BOUND overlaps. The low end of that 3777 range is bigger than the low end of the current range, so we 3778 are only interested if the current range is a real range, and 3779 not an ordinary case label. */ 3780 else if (high_bound 3781 && high_value 3782 && (tree_int_cst_compare ((tree) high_bound->key, 3783 high_value) 3784 <= 0)) 3785 node = high_bound; 3786 } 3787 /* If there was an overlap, issue an error. */ 3788 if (node) 3789 { 3790 tree duplicate = CASE_LABEL ((tree) node->value); 3791 3792 if (high_value) 3793 { 3794 error ("duplicate (or overlapping) case value"); 3795 error ("%Jthis is the first entry overlapping that value", duplicate); 3796 } 3797 else if (low_value) 3798 { 3799 error ("duplicate case value") ; 3800 error ("%Jpreviously used here", duplicate); 3801 } 3802 else 3803 { 3804 error ("multiple default labels in one switch"); 3805 error ("%Jthis is the first default label", duplicate); 3806 } 3807 goto error_out; 3808 } 3809 3810 /* Add a CASE_LABEL to the statement-tree. */ 3811 case_label = add_stmt (build_case_label (low_value, high_value, label)); 3812 /* Register this case label in the splay tree. */ 3813 splay_tree_insert (cases, 3814 (splay_tree_key) low_value, 3815 (splay_tree_value) case_label); 3816 3817 return case_label; 3818 3819 error_out: 3820 /* Add a label so that the back-end doesn't think that the beginning of 3821 the switch is unreachable. Note that we do not add a case label, as 3822 that just leads to duplicates and thence to failure later on. */ 3823 if (!cases->root) 3824 { 3825 tree t = create_artificial_label (); 3826 add_stmt (build_stmt (LABEL_EXPR, t)); 3827 } 3828 return error_mark_node; 3829} 3830 3831/* Subroutines of c_do_switch_warnings, called via splay_tree_foreach. 3832 Used to verify that case values match up with enumerator values. */ 3833 3834static void 3835match_case_to_enum_1 (tree key, tree type, tree label) 3836{ 3837 char buf[2 + 2*HOST_BITS_PER_WIDE_INT/4 + 1]; 3838 3839 /* ??? Not working too hard to print the double-word value. 3840 Should perhaps be done with %lwd in the diagnostic routines? */ 3841 if (TREE_INT_CST_HIGH (key) == 0) 3842 snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_UNSIGNED, 3843 TREE_INT_CST_LOW (key)); 3844 else if (!TYPE_UNSIGNED (type) 3845 && TREE_INT_CST_HIGH (key) == -1 3846 && TREE_INT_CST_LOW (key) != 0) 3847 snprintf (buf, sizeof (buf), "-" HOST_WIDE_INT_PRINT_UNSIGNED, 3848 -TREE_INT_CST_LOW (key)); 3849 else 3850 snprintf (buf, sizeof (buf), HOST_WIDE_INT_PRINT_DOUBLE_HEX, 3851 TREE_INT_CST_HIGH (key), TREE_INT_CST_LOW (key)); 3852 3853 if (TYPE_NAME (type) == 0) 3854 warning (0, "%Jcase value %qs not in enumerated type", 3855 CASE_LABEL (label), buf); 3856 else 3857 warning (0, "%Jcase value %qs not in enumerated type %qT", 3858 CASE_LABEL (label), buf, type); 3859} 3860 3861/* Subroutine of c_do_switch_warnings, called via splay_tree_foreach. 3862 Used to verify that case values match up with enumerator values. */ 3863 3864static int 3865match_case_to_enum (splay_tree_node node, void *data) 3866{ 3867 tree label = (tree) node->value; 3868 tree type = (tree) data; 3869 3870 /* Skip default case. */ 3871 if (!CASE_LOW (label)) 3872 return 0; 3873 3874 /* If CASE_LOW_SEEN is not set, that means CASE_LOW did not appear 3875 when we did our enum->case scan. Reset our scratch bit after. */ 3876 if (!CASE_LOW_SEEN (label)) 3877 match_case_to_enum_1 (CASE_LOW (label), type, label); 3878 else 3879 CASE_LOW_SEEN (label) = 0; 3880 3881 /* If CASE_HIGH is non-null, we have a range. If CASE_HIGH_SEEN is 3882 not set, that means that CASE_HIGH did not appear when we did our 3883 enum->case scan. Reset our scratch bit after. */ 3884 if (CASE_HIGH (label)) 3885 { 3886 if (!CASE_HIGH_SEEN (label)) 3887 match_case_to_enum_1 (CASE_HIGH (label), type, label); 3888 else 3889 CASE_HIGH_SEEN (label) = 0; 3890 } 3891 3892 return 0; 3893} 3894 3895/* Handle -Wswitch*. Called from the front end after parsing the 3896 switch construct. */ 3897/* ??? Should probably be somewhere generic, since other languages 3898 besides C and C++ would want this. At the moment, however, C/C++ 3899 are the only tree-ssa languages that support enumerations at all, 3900 so the point is moot. */ 3901 3902void 3903c_do_switch_warnings (splay_tree cases, location_t switch_location, 3904 tree type, tree cond) 3905{ 3906 splay_tree_node default_node; 3907 splay_tree_node node; 3908 tree chain; 3909 3910 if (!warn_switch && !warn_switch_enum && !warn_switch_default) 3911 return; 3912 3913 default_node = splay_tree_lookup (cases, (splay_tree_key) NULL); 3914 if (!default_node) 3915 warning (OPT_Wswitch_default, "%Hswitch missing default case", 3916 &switch_location); 3917 3918 /* From here on, we only care about about enumerated types. */ 3919 if (!type || TREE_CODE (type) != ENUMERAL_TYPE) 3920 return; 3921 3922 /* If the switch expression was an enumerated type, check that 3923 exactly all enumeration literals are covered by the cases. 3924 The check is made when -Wswitch was specified and there is no 3925 default case, or when -Wswitch-enum was specified. */ 3926 3927 if (!warn_switch_enum 3928 && !(warn_switch && !default_node)) 3929 return; 3930 3931 /* Clearing COND if it is not an integer constant simplifies 3932 the tests inside the loop below. */ 3933 if (TREE_CODE (cond) != INTEGER_CST) 3934 cond = NULL_TREE; 3935 3936 /* The time complexity here is O(N*lg(N)) worst case, but for the 3937 common case of monotonically increasing enumerators, it is 3938 O(N), since the nature of the splay tree will keep the next 3939 element adjacent to the root at all times. */ 3940 3941 for (chain = TYPE_VALUES (type); chain; chain = TREE_CHAIN (chain)) 3942 { 3943 tree value = TREE_VALUE (chain); 3944 node = splay_tree_lookup (cases, (splay_tree_key) value); 3945 if (node) 3946 { 3947 /* Mark the CASE_LOW part of the case entry as seen. */ 3948 tree label = (tree) node->value; 3949 CASE_LOW_SEEN (label) = 1; 3950 continue; 3951 } 3952 3953 /* Even though there wasn't an exact match, there might be a 3954 case range which includes the enumator's value. */ 3955 node = splay_tree_predecessor (cases, (splay_tree_key) value); 3956 if (node && CASE_HIGH ((tree) node->value)) 3957 { 3958 tree label = (tree) node->value; 3959 int cmp = tree_int_cst_compare (CASE_HIGH (label), value); 3960 if (cmp >= 0) 3961 { 3962 /* If we match the upper bound exactly, mark the CASE_HIGH 3963 part of the case entry as seen. */ 3964 if (cmp == 0) 3965 CASE_HIGH_SEEN (label) = 1; 3966 continue; 3967 } 3968 } 3969 3970 /* We've now determined that this enumerated literal isn't 3971 handled by the case labels of the switch statement. */ 3972 3973 /* If the switch expression is a constant, we only really care 3974 about whether that constant is handled by the switch. */ 3975 if (cond && tree_int_cst_compare (cond, value)) 3976 continue; 3977 3978 warning (0, "%Henumeration value %qE not handled in switch", 3979 &switch_location, TREE_PURPOSE (chain)); 3980 } 3981 3982 /* Warn if there are case expressions that don't correspond to 3983 enumerators. This can occur since C and C++ don't enforce 3984 type-checking of assignments to enumeration variables. 3985 3986 The time complexity here is now always O(N) worst case, since 3987 we should have marked both the lower bound and upper bound of 3988 every disjoint case label, with CASE_LOW_SEEN and CASE_HIGH_SEEN 3989 above. This scan also resets those fields. */ 3990 splay_tree_foreach (cases, match_case_to_enum, type); 3991} 3992 3993/* Finish an expression taking the address of LABEL (an 3994 IDENTIFIER_NODE). Returns an expression for the address. */ 3995 3996tree 3997finish_label_address_expr (tree label) 3998{ 3999 tree result; 4000 4001 if (pedantic) 4002 pedwarn ("taking the address of a label is non-standard"); 4003 4004 if (label == error_mark_node) 4005 return error_mark_node; 4006 4007 label = lookup_label (label); 4008 if (label == NULL_TREE) 4009 result = null_pointer_node; 4010 else 4011 { 4012 TREE_USED (label) = 1; 4013 result = build1 (ADDR_EXPR, ptr_type_node, label); 4014 /* The current function in not necessarily uninlinable. 4015 Computed gotos are incompatible with inlining, but the value 4016 here could be used only in a diagnostic, for example. */ 4017 } 4018 4019 return result; 4020} 4021 4022/* Hook used by expand_expr to expand language-specific tree codes. */ 4023/* The only things that should go here are bits needed to expand 4024 constant initializers. Everything else should be handled by the 4025 gimplification routines. */ 4026 4027rtx 4028c_expand_expr (tree exp, rtx target, enum machine_mode tmode, 4029 int modifier /* Actually enum_modifier. */, 4030 rtx *alt_rtl) 4031{ 4032 switch (TREE_CODE (exp)) 4033 { 4034 case COMPOUND_LITERAL_EXPR: 4035 { 4036 /* Initialize the anonymous variable declared in the compound 4037 literal, then return the variable. */ 4038 tree decl = COMPOUND_LITERAL_EXPR_DECL (exp); 4039 emit_local_var (decl); 4040 return expand_expr_real (decl, target, tmode, modifier, alt_rtl); 4041 } 4042 4043 default: 4044 gcc_unreachable (); 4045 } 4046} 4047 4048/* Hook used by staticp to handle language-specific tree codes. */ 4049 4050tree 4051c_staticp (tree exp) 4052{ 4053 return (TREE_CODE (exp) == COMPOUND_LITERAL_EXPR 4054 && TREE_STATIC (COMPOUND_LITERAL_EXPR_DECL (exp)) 4055 ? exp : NULL); 4056} 4057 4058 4059/* Given a boolean expression ARG, return a tree representing an increment 4060 or decrement (as indicated by CODE) of ARG. The front end must check for 4061 invalid cases (e.g., decrement in C++). */ 4062tree 4063boolean_increment (enum tree_code code, tree arg) 4064{ 4065 tree val; 4066 tree true_res = boolean_true_node; 4067 4068 arg = stabilize_reference (arg); 4069 switch (code) 4070 { 4071 case PREINCREMENT_EXPR: 4072 val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res); 4073 break; 4074 case POSTINCREMENT_EXPR: 4075 val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, true_res); 4076 arg = save_expr (arg); 4077 val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg); 4078 val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val); 4079 break; 4080 case PREDECREMENT_EXPR: 4081 val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, 4082 invert_truthvalue (arg)); 4083 break; 4084 case POSTDECREMENT_EXPR: 4085 val = build2 (MODIFY_EXPR, TREE_TYPE (arg), arg, 4086 invert_truthvalue (arg)); 4087 arg = save_expr (arg); 4088 val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), val, arg); 4089 val = build2 (COMPOUND_EXPR, TREE_TYPE (arg), arg, val); 4090 break; 4091 default: 4092 gcc_unreachable (); 4093 } 4094 TREE_SIDE_EFFECTS (val) = 1; 4095 return val; 4096} 4097 4098/* Built-in macros for stddef.h, that require macros defined in this 4099 file. */ 4100void 4101c_stddef_cpp_builtins(void) 4102{ 4103 builtin_define_with_value ("__SIZE_TYPE__", SIZE_TYPE, 0); 4104 builtin_define_with_value ("__PTRDIFF_TYPE__", PTRDIFF_TYPE, 0); 4105 builtin_define_with_value ("__WCHAR_TYPE__", MODIFIED_WCHAR_TYPE, 0); 4106 builtin_define_with_value ("__WINT_TYPE__", WINT_TYPE, 0); 4107 builtin_define_with_value ("__INTMAX_TYPE__", INTMAX_TYPE, 0); 4108 builtin_define_with_value ("__UINTMAX_TYPE__", UINTMAX_TYPE, 0); 4109} 4110 4111static void 4112c_init_attributes (void) 4113{ 4114 /* Fill in the built_in_attributes array. */ 4115#define DEF_ATTR_NULL_TREE(ENUM) \ 4116 built_in_attributes[(int) ENUM] = NULL_TREE; 4117#define DEF_ATTR_INT(ENUM, VALUE) \ 4118 built_in_attributes[(int) ENUM] = build_int_cst (NULL_TREE, VALUE); 4119#define DEF_ATTR_IDENT(ENUM, STRING) \ 4120 built_in_attributes[(int) ENUM] = get_identifier (STRING); 4121#define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) \ 4122 built_in_attributes[(int) ENUM] \ 4123 = tree_cons (built_in_attributes[(int) PURPOSE], \ 4124 built_in_attributes[(int) VALUE], \ 4125 built_in_attributes[(int) CHAIN]); 4126#include "builtin-attrs.def" 4127#undef DEF_ATTR_NULL_TREE 4128#undef DEF_ATTR_INT 4129#undef DEF_ATTR_IDENT 4130#undef DEF_ATTR_TREE_LIST 4131} 4132 4133/* Attribute handlers common to C front ends. */ 4134 4135/* Handle a "packed" attribute; arguments as in 4136 struct attribute_spec.handler. */ 4137 4138static tree 4139handle_packed_attribute (tree *node, tree name, tree ARG_UNUSED (args), 4140 int flags, bool *no_add_attrs) 4141{ 4142 if (TYPE_P (*node)) 4143 { 4144 if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE)) 4145 *node = build_variant_type_copy (*node); 4146 TYPE_PACKED (*node) = 1; 4147 } 4148 else if (TREE_CODE (*node) == FIELD_DECL) 4149 { 4150 if (TYPE_ALIGN (TREE_TYPE (*node)) <= BITS_PER_UNIT) 4151 warning (OPT_Wattributes, 4152 "%qE attribute ignored for field of type %qT", 4153 name, TREE_TYPE (*node)); 4154 else 4155 DECL_PACKED (*node) = 1; 4156 } 4157 /* We can't set DECL_PACKED for a VAR_DECL, because the bit is 4158 used for DECL_REGISTER. It wouldn't mean anything anyway. 4159 We can't set DECL_PACKED on the type of a TYPE_DECL, because 4160 that changes what the typedef is typing. */ 4161 else 4162 { 4163 warning (OPT_Wattributes, "%qE attribute ignored", name); 4164 *no_add_attrs = true; 4165 } 4166 4167 return NULL_TREE; 4168} 4169 4170/* Handle a "nocommon" attribute; arguments as in 4171 struct attribute_spec.handler. */ 4172 4173static tree 4174handle_nocommon_attribute (tree *node, tree name, 4175 tree ARG_UNUSED (args), 4176 int ARG_UNUSED (flags), bool *no_add_attrs) 4177{ 4178 if (TREE_CODE (*node) == VAR_DECL) 4179 DECL_COMMON (*node) = 0; 4180 else 4181 { 4182 warning (OPT_Wattributes, "%qE attribute ignored", name); 4183 *no_add_attrs = true; 4184 } 4185 4186 return NULL_TREE; 4187} 4188 4189/* Handle a "common" attribute; arguments as in 4190 struct attribute_spec.handler. */ 4191 4192static tree 4193handle_common_attribute (tree *node, tree name, tree ARG_UNUSED (args), 4194 int ARG_UNUSED (flags), bool *no_add_attrs) 4195{ 4196 if (TREE_CODE (*node) == VAR_DECL) 4197 DECL_COMMON (*node) = 1; 4198 else 4199 { 4200 warning (OPT_Wattributes, "%qE attribute ignored", name); 4201 *no_add_attrs = true; 4202 } 4203 4204 return NULL_TREE; 4205} 4206 4207/* Handle a "noreturn" attribute; arguments as in 4208 struct attribute_spec.handler. */ 4209 4210static tree 4211handle_noreturn_attribute (tree *node, tree name, tree ARG_UNUSED (args), 4212 int ARG_UNUSED (flags), bool *no_add_attrs) 4213{ 4214 tree type = TREE_TYPE (*node); 4215 4216 /* See FIXME comment in c_common_attribute_table. */ 4217 if (TREE_CODE (*node) == FUNCTION_DECL) 4218 TREE_THIS_VOLATILE (*node) = 1; 4219 else if (TREE_CODE (type) == POINTER_TYPE 4220 && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE) 4221 TREE_TYPE (*node) 4222 = build_pointer_type 4223 (build_type_variant (TREE_TYPE (type), 4224 TYPE_READONLY (TREE_TYPE (type)), 1)); 4225 else 4226 { 4227 warning (OPT_Wattributes, "%qE attribute ignored", name); 4228 *no_add_attrs = true; 4229 } 4230 4231 return NULL_TREE; 4232} 4233 4234/* Handle a "noinline" attribute; arguments as in 4235 struct attribute_spec.handler. */ 4236 4237static tree 4238handle_noinline_attribute (tree *node, tree name, 4239 tree ARG_UNUSED (args), 4240 int ARG_UNUSED (flags), bool *no_add_attrs) 4241{ 4242 if (TREE_CODE (*node) == FUNCTION_DECL) 4243 DECL_UNINLINABLE (*node) = 1; 4244 else 4245 { 4246 warning (OPT_Wattributes, "%qE attribute ignored", name); 4247 *no_add_attrs = true; 4248 } 4249 4250 return NULL_TREE; 4251} 4252 4253/* Handle a "always_inline" attribute; arguments as in 4254 struct attribute_spec.handler. */ 4255 4256static tree 4257handle_always_inline_attribute (tree *node, tree name, 4258 tree ARG_UNUSED (args), 4259 int ARG_UNUSED (flags), 4260 bool *no_add_attrs) 4261{ 4262 if (TREE_CODE (*node) == FUNCTION_DECL) 4263 { 4264 /* Do nothing else, just set the attribute. We'll get at 4265 it later with lookup_attribute. */ 4266 } 4267 else 4268 { 4269 warning (OPT_Wattributes, "%qE attribute ignored", name); 4270 *no_add_attrs = true; 4271 } 4272 4273 return NULL_TREE; 4274} 4275 4276/* Handle a "gnu_inline" attribute; arguments as in 4277 struct attribute_spec.handler. */ 4278 4279static tree 4280handle_gnu_inline_attribute (tree *node, tree name, 4281 tree ARG_UNUSED (args), 4282 int ARG_UNUSED (flags), 4283 bool *no_add_attrs) 4284{ 4285 if (TREE_CODE (*node) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (*node)) 4286 { 4287 /* Do nothing else, just set the attribute. We'll get at 4288 it later with lookup_attribute. */ 4289 } 4290 else 4291 { 4292 warning (OPT_Wattributes, "%qE attribute ignored", name); 4293 *no_add_attrs = true; 4294 } 4295 4296 return NULL_TREE; 4297} 4298 4299/* Handle a "flatten" attribute; arguments as in 4300 struct attribute_spec.handler. */ 4301 4302static tree 4303handle_flatten_attribute (tree *node, tree name, 4304 tree args ATTRIBUTE_UNUSED, 4305 int flags ATTRIBUTE_UNUSED, bool *no_add_attrs) 4306{ 4307 if (TREE_CODE (*node) == FUNCTION_DECL) 4308 /* Do nothing else, just set the attribute. We'll get at 4309 it later with lookup_attribute. */ 4310 ; 4311 else 4312 { 4313 warning (OPT_Wattributes, "%qE attribute ignored", name); 4314 *no_add_attrs = true; 4315 } 4316 4317 return NULL_TREE; 4318} 4319 4320 4321/* Handle a "used" attribute; arguments as in 4322 struct attribute_spec.handler. */ 4323 4324static tree 4325handle_used_attribute (tree *pnode, tree name, tree ARG_UNUSED (args), 4326 int ARG_UNUSED (flags), bool *no_add_attrs) 4327{ 4328 tree node = *pnode; 4329 4330 if (TREE_CODE (node) == FUNCTION_DECL 4331 || (TREE_CODE (node) == VAR_DECL && TREE_STATIC (node))) 4332 { 4333 TREE_USED (node) = 1; 4334 DECL_PRESERVE_P (node) = 1; 4335 } 4336 else 4337 { 4338 warning (OPT_Wattributes, "%qE attribute ignored", name); 4339 *no_add_attrs = true; 4340 } 4341 4342 return NULL_TREE; 4343} 4344 4345/* Handle a "unused" attribute; arguments as in 4346 struct attribute_spec.handler. */ 4347 4348static tree 4349handle_unused_attribute (tree *node, tree name, tree ARG_UNUSED (args), 4350 int flags, bool *no_add_attrs) 4351{ 4352 if (DECL_P (*node)) 4353 { 4354 tree decl = *node; 4355 4356 if (TREE_CODE (decl) == PARM_DECL 4357 || TREE_CODE (decl) == VAR_DECL 4358 || TREE_CODE (decl) == FUNCTION_DECL 4359 || TREE_CODE (decl) == LABEL_DECL 4360 || TREE_CODE (decl) == TYPE_DECL) 4361 TREE_USED (decl) = 1; 4362 else 4363 { 4364 warning (OPT_Wattributes, "%qE attribute ignored", name); 4365 *no_add_attrs = true; 4366 } 4367 } 4368 else 4369 { 4370 if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE)) 4371 *node = build_variant_type_copy (*node); 4372 TREE_USED (*node) = 1; 4373 } 4374 4375 return NULL_TREE; 4376} 4377 4378/* Handle a "externally_visible" attribute; arguments as in 4379 struct attribute_spec.handler. */ 4380 4381static tree 4382handle_externally_visible_attribute (tree *pnode, tree name, 4383 tree ARG_UNUSED (args), 4384 int ARG_UNUSED (flags), 4385 bool *no_add_attrs) 4386{ 4387 tree node = *pnode; 4388 4389 if (TREE_CODE (node) == FUNCTION_DECL || TREE_CODE (node) == VAR_DECL) 4390 { 4391 if ((!TREE_STATIC (node) && TREE_CODE (node) != FUNCTION_DECL 4392 && !DECL_EXTERNAL (node)) || !TREE_PUBLIC (node)) 4393 { 4394 warning (OPT_Wattributes, 4395 "%qE attribute have effect only on public objects", name); 4396 *no_add_attrs = true; 4397 } 4398 } 4399 else 4400 { 4401 warning (OPT_Wattributes, "%qE attribute ignored", name); 4402 *no_add_attrs = true; 4403 } 4404 4405 return NULL_TREE; 4406} 4407 4408/* Handle a "const" attribute; arguments as in 4409 struct attribute_spec.handler. */ 4410 4411static tree 4412handle_const_attribute (tree *node, tree name, tree ARG_UNUSED (args), 4413 int ARG_UNUSED (flags), bool *no_add_attrs) 4414{ 4415 tree type = TREE_TYPE (*node); 4416 4417 /* See FIXME comment on noreturn in c_common_attribute_table. */ 4418 if (TREE_CODE (*node) == FUNCTION_DECL) 4419 TREE_READONLY (*node) = 1; 4420 else if (TREE_CODE (type) == POINTER_TYPE 4421 && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE) 4422 TREE_TYPE (*node) 4423 = build_pointer_type 4424 (build_type_variant (TREE_TYPE (type), 1, 4425 TREE_THIS_VOLATILE (TREE_TYPE (type)))); 4426 else 4427 { 4428 warning (OPT_Wattributes, "%qE attribute ignored", name); 4429 *no_add_attrs = true; 4430 } 4431 4432 return NULL_TREE; 4433} 4434 4435/* Handle a "transparent_union" attribute; arguments as in 4436 struct attribute_spec.handler. */ 4437 4438static tree 4439handle_transparent_union_attribute (tree *node, tree name, 4440 tree ARG_UNUSED (args), int flags, 4441 bool *no_add_attrs) 4442{ 4443 tree type = NULL; 4444 4445 *no_add_attrs = true; 4446 4447 if (DECL_P (*node)) 4448 { 4449 if (TREE_CODE (*node) != TYPE_DECL) 4450 goto ignored; 4451 node = &TREE_TYPE (*node); 4452 type = *node; 4453 } 4454 else if (TYPE_P (*node)) 4455 type = *node; 4456 else 4457 goto ignored; 4458 4459 if (TREE_CODE (type) == UNION_TYPE) 4460 { 4461 /* When IN_PLACE is set, leave the check for FIELDS and MODE to 4462 the code in finish_struct. */ 4463 if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE)) 4464 { 4465 if (TYPE_FIELDS (type) == NULL_TREE 4466 || TYPE_MODE (type) != DECL_MODE (TYPE_FIELDS (type))) 4467 goto ignored; 4468 4469 /* A type variant isn't good enough, since we don't a cast 4470 to such a type removed as a no-op. */ 4471 *node = type = build_duplicate_type (type); 4472 } 4473 4474 TYPE_TRANSPARENT_UNION (type) = 1; 4475 return NULL_TREE; 4476 } 4477 4478 ignored: 4479 warning (OPT_Wattributes, "%qE attribute ignored", name); 4480 return NULL_TREE; 4481} 4482 4483/* Handle a "constructor" attribute; arguments as in 4484 struct attribute_spec.handler. */ 4485 4486static tree 4487handle_constructor_attribute (tree *node, tree name, 4488 tree ARG_UNUSED (args), 4489 int ARG_UNUSED (flags), 4490 bool *no_add_attrs) 4491{ 4492 tree decl = *node; 4493 tree type = TREE_TYPE (decl); 4494 4495 if (TREE_CODE (decl) == FUNCTION_DECL 4496 && TREE_CODE (type) == FUNCTION_TYPE 4497 && decl_function_context (decl) == 0) 4498 { 4499 DECL_STATIC_CONSTRUCTOR (decl) = 1; 4500 TREE_USED (decl) = 1; 4501 } 4502 else 4503 { 4504 warning (OPT_Wattributes, "%qE attribute ignored", name); 4505 *no_add_attrs = true; 4506 } 4507 4508 return NULL_TREE; 4509} 4510 4511/* Handle a "destructor" attribute; arguments as in 4512 struct attribute_spec.handler. */ 4513 4514static tree 4515handle_destructor_attribute (tree *node, tree name, 4516 tree ARG_UNUSED (args), 4517 int ARG_UNUSED (flags), 4518 bool *no_add_attrs) 4519{ 4520 tree decl = *node; 4521 tree type = TREE_TYPE (decl); 4522 4523 if (TREE_CODE (decl) == FUNCTION_DECL 4524 && TREE_CODE (type) == FUNCTION_TYPE 4525 && decl_function_context (decl) == 0) 4526 { 4527 DECL_STATIC_DESTRUCTOR (decl) = 1; 4528 TREE_USED (decl) = 1; 4529 } 4530 else 4531 { 4532 warning (OPT_Wattributes, "%qE attribute ignored", name); 4533 *no_add_attrs = true; 4534 } 4535 4536 return NULL_TREE; 4537} 4538 4539/* Handle a "mode" attribute; arguments as in 4540 struct attribute_spec.handler. */ 4541 4542static tree 4543handle_mode_attribute (tree *node, tree name, tree args, 4544 int ARG_UNUSED (flags), bool *no_add_attrs) 4545{ 4546 tree type = *node; 4547 4548 *no_add_attrs = true; 4549 4550 if (TREE_CODE (TREE_VALUE (args)) != IDENTIFIER_NODE) 4551 warning (OPT_Wattributes, "%qE attribute ignored", name); 4552 else 4553 { 4554 int j; 4555 const char *p = IDENTIFIER_POINTER (TREE_VALUE (args)); 4556 int len = strlen (p); 4557 enum machine_mode mode = VOIDmode; 4558 tree typefm; 4559 bool valid_mode; 4560 4561 if (len > 4 && p[0] == '_' && p[1] == '_' 4562 && p[len - 1] == '_' && p[len - 2] == '_') 4563 { 4564 char *newp = (char *) alloca (len - 1); 4565 4566 strcpy (newp, &p[2]); 4567 newp[len - 4] = '\0'; 4568 p = newp; 4569 } 4570 4571 /* Change this type to have a type with the specified mode. 4572 First check for the special modes. */ 4573 if (!strcmp (p, "byte")) 4574 mode = byte_mode; 4575 else if (!strcmp (p, "word")) 4576 mode = word_mode; 4577 else if (!strcmp (p, "pointer")) 4578 mode = ptr_mode; 4579 else 4580 for (j = 0; j < NUM_MACHINE_MODES; j++) 4581 if (!strcmp (p, GET_MODE_NAME (j))) 4582 { 4583 mode = (enum machine_mode) j; 4584 break; 4585 } 4586 4587 if (mode == VOIDmode) 4588 { 4589 error ("unknown machine mode %qs", p); 4590 return NULL_TREE; 4591 } 4592 4593 valid_mode = false; 4594 switch (GET_MODE_CLASS (mode)) 4595 { 4596 case MODE_INT: 4597 case MODE_PARTIAL_INT: 4598 case MODE_FLOAT: 4599 case MODE_DECIMAL_FLOAT: 4600 valid_mode = targetm.scalar_mode_supported_p (mode); 4601 break; 4602 4603 case MODE_COMPLEX_INT: 4604 case MODE_COMPLEX_FLOAT: 4605 valid_mode = targetm.scalar_mode_supported_p (GET_MODE_INNER (mode)); 4606 break; 4607 4608 case MODE_VECTOR_INT: 4609 case MODE_VECTOR_FLOAT: 4610 warning (OPT_Wattributes, "specifying vector types with " 4611 "__attribute__ ((mode)) is deprecated"); 4612 warning (OPT_Wattributes, 4613 "use __attribute__ ((vector_size)) instead"); 4614 valid_mode = vector_mode_valid_p (mode); 4615 break; 4616 4617 default: 4618 break; 4619 } 4620 if (!valid_mode) 4621 { 4622 error ("unable to emulate %qs", p); 4623 return NULL_TREE; 4624 } 4625 4626 if (POINTER_TYPE_P (type)) 4627 { 4628 tree (*fn)(tree, enum machine_mode, bool); 4629 4630 if (!targetm.valid_pointer_mode (mode)) 4631 { 4632 error ("invalid pointer mode %qs", p); 4633 return NULL_TREE; 4634 } 4635 4636 if (TREE_CODE (type) == POINTER_TYPE) 4637 fn = build_pointer_type_for_mode; 4638 else 4639 fn = build_reference_type_for_mode; 4640 typefm = fn (TREE_TYPE (type), mode, false); 4641 } 4642 else 4643 typefm = lang_hooks.types.type_for_mode (mode, TYPE_UNSIGNED (type)); 4644 4645 if (typefm == NULL_TREE) 4646 { 4647 error ("no data type for mode %qs", p); 4648 return NULL_TREE; 4649 } 4650 else if (TREE_CODE (type) == ENUMERAL_TYPE) 4651 { 4652 /* For enumeral types, copy the precision from the integer 4653 type returned above. If not an INTEGER_TYPE, we can't use 4654 this mode for this type. */ 4655 if (TREE_CODE (typefm) != INTEGER_TYPE) 4656 { 4657 error ("cannot use mode %qs for enumeral types", p); 4658 return NULL_TREE; 4659 } 4660 4661 if (flags & ATTR_FLAG_TYPE_IN_PLACE) 4662 { 4663 TYPE_PRECISION (type) = TYPE_PRECISION (typefm); 4664 typefm = type; 4665 } 4666 else 4667 { 4668 /* We cannot build a type variant, as there's code that assumes 4669 that TYPE_MAIN_VARIANT has the same mode. This includes the 4670 debug generators. Instead, create a subrange type. This 4671 results in all of the enumeral values being emitted only once 4672 in the original, and the subtype gets them by reference. */ 4673 if (TYPE_UNSIGNED (type)) 4674 typefm = make_unsigned_type (TYPE_PRECISION (typefm)); 4675 else 4676 typefm = make_signed_type (TYPE_PRECISION (typefm)); 4677 TREE_TYPE (typefm) = type; 4678 } 4679 } 4680 else if (VECTOR_MODE_P (mode) 4681 ? TREE_CODE (type) != TREE_CODE (TREE_TYPE (typefm)) 4682 : TREE_CODE (type) != TREE_CODE (typefm)) 4683 { 4684 error ("mode %qs applied to inappropriate type", p); 4685 return NULL_TREE; 4686 } 4687 4688 *node = typefm; 4689 } 4690 4691 return NULL_TREE; 4692} 4693 4694/* Handle a "section" attribute; arguments as in 4695 struct attribute_spec.handler. */ 4696 4697static tree 4698handle_section_attribute (tree *node, tree ARG_UNUSED (name), tree args, 4699 int ARG_UNUSED (flags), bool *no_add_attrs) 4700{ 4701 tree decl = *node; 4702 4703 if (targetm.have_named_sections) 4704 { 4705 user_defined_section_attribute = true; 4706 4707 if ((TREE_CODE (decl) == FUNCTION_DECL 4708 || TREE_CODE (decl) == VAR_DECL) 4709 && TREE_CODE (TREE_VALUE (args)) == STRING_CST) 4710 { 4711 if (TREE_CODE (decl) == VAR_DECL 4712 && current_function_decl != NULL_TREE 4713 && !TREE_STATIC (decl)) 4714 { 4715 error ("%Jsection attribute cannot be specified for " 4716 "local variables", decl); 4717 *no_add_attrs = true; 4718 } 4719 4720 /* The decl may have already been given a section attribute 4721 from a previous declaration. Ensure they match. */ 4722 else if (DECL_SECTION_NAME (decl) != NULL_TREE 4723 && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)), 4724 TREE_STRING_POINTER (TREE_VALUE (args))) != 0) 4725 { 4726 error ("section of %q+D conflicts with previous declaration", 4727 *node); 4728 *no_add_attrs = true; 4729 } 4730 else 4731 DECL_SECTION_NAME (decl) = TREE_VALUE (args); 4732 } 4733 else 4734 { 4735 error ("section attribute not allowed for %q+D", *node); 4736 *no_add_attrs = true; 4737 } 4738 } 4739 else 4740 { 4741 error ("%Jsection attributes are not supported for this target", *node); 4742 *no_add_attrs = true; 4743 } 4744 4745 return NULL_TREE; 4746} 4747 4748/* Handle a "aligned" attribute; arguments as in 4749 struct attribute_spec.handler. */ 4750 4751static tree 4752handle_aligned_attribute (tree *node, tree ARG_UNUSED (name), tree args, 4753 int flags, bool *no_add_attrs) 4754{ 4755 tree decl = NULL_TREE; 4756 tree *type = NULL; 4757 int is_type = 0; 4758 tree align_expr = (args ? TREE_VALUE (args) 4759 : size_int (BIGGEST_ALIGNMENT / BITS_PER_UNIT)); 4760 int i; 4761 4762 if (DECL_P (*node)) 4763 { 4764 decl = *node; 4765 type = &TREE_TYPE (decl); 4766 is_type = TREE_CODE (*node) == TYPE_DECL; 4767 } 4768 else if (TYPE_P (*node)) 4769 type = node, is_type = 1; 4770 4771 if (TREE_CODE (align_expr) != INTEGER_CST) 4772 { 4773 error ("requested alignment is not a constant"); 4774 *no_add_attrs = true; 4775 } 4776 else if ((i = tree_log2 (align_expr)) == -1) 4777 { 4778 error ("requested alignment is not a power of 2"); 4779 *no_add_attrs = true; 4780 } 4781 else if (i > HOST_BITS_PER_INT - 2) 4782 { 4783 error ("requested alignment is too large"); 4784 *no_add_attrs = true; 4785 } 4786 else if (is_type) 4787 { 4788 /* If we have a TYPE_DECL, then copy the type, so that we 4789 don't accidentally modify a builtin type. See pushdecl. */ 4790 if (decl && TREE_TYPE (decl) != error_mark_node 4791 && DECL_ORIGINAL_TYPE (decl) == NULL_TREE) 4792 { 4793 tree tt = TREE_TYPE (decl); 4794 *type = build_variant_type_copy (*type); 4795 DECL_ORIGINAL_TYPE (decl) = tt; 4796 TYPE_NAME (*type) = decl; 4797 TREE_USED (*type) = TREE_USED (decl); 4798 TREE_TYPE (decl) = *type; 4799 } 4800 else if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE)) 4801 *type = build_variant_type_copy (*type); 4802 4803 TYPE_ALIGN (*type) = (1 << i) * BITS_PER_UNIT; 4804 TYPE_USER_ALIGN (*type) = 1; 4805 } 4806 else if (TREE_CODE (decl) != VAR_DECL 4807 && TREE_CODE (decl) != FIELD_DECL) 4808 { 4809 error ("alignment may not be specified for %q+D", decl); 4810 *no_add_attrs = true; 4811 } 4812 else 4813 { 4814 DECL_ALIGN (decl) = (1 << i) * BITS_PER_UNIT; 4815 DECL_USER_ALIGN (decl) = 1; 4816 } 4817 4818 return NULL_TREE; 4819} 4820 4821/* Handle a "weak" attribute; arguments as in 4822 struct attribute_spec.handler. */ 4823 4824static tree 4825handle_weak_attribute (tree *node, tree name, 4826 tree ARG_UNUSED (args), 4827 int ARG_UNUSED (flags), 4828 bool * ARG_UNUSED (no_add_attrs)) 4829{ 4830 if (TREE_CODE (*node) == FUNCTION_DECL 4831 || TREE_CODE (*node) == VAR_DECL) 4832 declare_weak (*node); 4833 else 4834 warning (OPT_Wattributes, "%qE attribute ignored", name); 4835 4836 4837 return NULL_TREE; 4838} 4839 4840/* Handle an "alias" attribute; arguments as in 4841 struct attribute_spec.handler. */ 4842 4843static tree 4844handle_alias_attribute (tree *node, tree name, tree args, 4845 int ARG_UNUSED (flags), bool *no_add_attrs) 4846{ 4847 tree decl = *node; 4848 4849 if ((TREE_CODE (decl) == FUNCTION_DECL && DECL_INITIAL (decl)) 4850 || (TREE_CODE (decl) != FUNCTION_DECL 4851 && TREE_PUBLIC (decl) && !DECL_EXTERNAL (decl)) 4852 /* A static variable declaration is always a tentative definition, 4853 but the alias is a non-tentative definition which overrides. */ 4854 || (TREE_CODE (decl) != FUNCTION_DECL 4855 && ! TREE_PUBLIC (decl) && DECL_INITIAL (decl))) 4856 { 4857 error ("%q+D defined both normally and as an alias", decl); 4858 *no_add_attrs = true; 4859 } 4860 4861 /* Note that the very first time we process a nested declaration, 4862 decl_function_context will not be set. Indeed, *would* never 4863 be set except for the DECL_INITIAL/DECL_EXTERNAL frobbery that 4864 we do below. After such frobbery, pushdecl would set the context. 4865 In any case, this is never what we want. */ 4866 else if (decl_function_context (decl) == 0 && current_function_decl == NULL) 4867 { 4868 tree id; 4869 4870 id = TREE_VALUE (args); 4871 if (TREE_CODE (id) != STRING_CST) 4872 { 4873 error ("alias argument not a string"); 4874 *no_add_attrs = true; 4875 return NULL_TREE; 4876 } 4877 id = get_identifier (TREE_STRING_POINTER (id)); 4878 /* This counts as a use of the object pointed to. */ 4879 TREE_USED (id) = 1; 4880 4881 if (TREE_CODE (decl) == FUNCTION_DECL) 4882 DECL_INITIAL (decl) = error_mark_node; 4883 else 4884 { 4885 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl))) 4886 DECL_EXTERNAL (decl) = 1; 4887 else 4888 DECL_EXTERNAL (decl) = 0; 4889 TREE_STATIC (decl) = 1; 4890 } 4891 } 4892 else 4893 { 4894 warning (OPT_Wattributes, "%qE attribute ignored", name); 4895 *no_add_attrs = true; 4896 } 4897 4898 return NULL_TREE; 4899} 4900 4901/* Handle a "weakref" attribute; arguments as in struct 4902 attribute_spec.handler. */ 4903 4904static tree 4905handle_weakref_attribute (tree *node, tree ARG_UNUSED (name), tree args, 4906 int flags, bool *no_add_attrs) 4907{ 4908 tree attr = NULL_TREE; 4909 4910 /* We must ignore the attribute when it is associated with 4911 local-scoped decls, since attribute alias is ignored and many 4912 such symbols do not even have a DECL_WEAK field. */ 4913 if (decl_function_context (*node) || current_function_decl) 4914 { 4915 warning (OPT_Wattributes, "%qE attribute ignored", name); 4916 *no_add_attrs = true; 4917 return NULL_TREE; 4918 } 4919 4920 /* The idea here is that `weakref("name")' mutates into `weakref, 4921 alias("name")', and weakref without arguments, in turn, 4922 implicitly adds weak. */ 4923 4924 if (args) 4925 { 4926 attr = tree_cons (get_identifier ("alias"), args, attr); 4927 attr = tree_cons (get_identifier ("weakref"), NULL_TREE, attr); 4928 4929 *no_add_attrs = true; 4930 4931 decl_attributes (node, attr, flags); 4932 } 4933 else 4934 { 4935 if (lookup_attribute ("alias", DECL_ATTRIBUTES (*node))) 4936 error ("%Jweakref attribute must appear before alias attribute", 4937 *node); 4938 4939 /* Can't call declare_weak because it wants this to be TREE_PUBLIC, 4940 and that isn't supported; and because it wants to add it to 4941 the list of weak decls, which isn't helpful. */ 4942 DECL_WEAK (*node) = 1; 4943 } 4944 4945 return NULL_TREE; 4946} 4947 4948/* Handle an "visibility" attribute; arguments as in 4949 struct attribute_spec.handler. */ 4950 4951static tree 4952handle_visibility_attribute (tree *node, tree name, tree args, 4953 int ARG_UNUSED (flags), 4954 bool *ARG_UNUSED (no_add_attrs)) 4955{ 4956 tree decl = *node; 4957 tree id = TREE_VALUE (args); 4958 enum symbol_visibility vis; 4959 4960 if (TYPE_P (*node)) 4961 { 4962 if (TREE_CODE (*node) == ENUMERAL_TYPE) 4963 /* OK */; 4964 else if (TREE_CODE (*node) != RECORD_TYPE && TREE_CODE (*node) != UNION_TYPE) 4965 { 4966 warning (OPT_Wattributes, "%qE attribute ignored on non-class types", 4967 name); 4968 return NULL_TREE; 4969 } 4970 else if (TYPE_FIELDS (*node)) 4971 { 4972 error ("%qE attribute ignored because %qT is already defined", 4973 name, *node); 4974 return NULL_TREE; 4975 } 4976 } 4977 else if (decl_function_context (decl) != 0 || !TREE_PUBLIC (decl)) 4978 { 4979 warning (OPT_Wattributes, "%qE attribute ignored", name); 4980 return NULL_TREE; 4981 } 4982 4983 if (TREE_CODE (id) != STRING_CST) 4984 { 4985 error ("visibility argument not a string"); 4986 return NULL_TREE; 4987 } 4988 4989 /* If this is a type, set the visibility on the type decl. */ 4990 if (TYPE_P (decl)) 4991 { 4992 decl = TYPE_NAME (decl); 4993 if (!decl) 4994 return NULL_TREE; 4995 if (TREE_CODE (decl) == IDENTIFIER_NODE) 4996 { 4997 warning (OPT_Wattributes, "%qE attribute ignored on types", 4998 name); 4999 return NULL_TREE; 5000 } 5001 } 5002 5003 if (strcmp (TREE_STRING_POINTER (id), "default") == 0) 5004 vis = VISIBILITY_DEFAULT; 5005 else if (strcmp (TREE_STRING_POINTER (id), "internal") == 0) 5006 vis = VISIBILITY_INTERNAL; 5007 else if (strcmp (TREE_STRING_POINTER (id), "hidden") == 0) 5008 vis = VISIBILITY_HIDDEN; 5009 else if (strcmp (TREE_STRING_POINTER (id), "protected") == 0) 5010 vis = VISIBILITY_PROTECTED; 5011 else 5012 { 5013 error ("visibility argument must be one of \"default\", \"hidden\", \"protected\" or \"internal\""); 5014 vis = VISIBILITY_DEFAULT; 5015 } 5016 5017 if (DECL_VISIBILITY_SPECIFIED (decl) 5018 && vis != DECL_VISIBILITY (decl) 5019 && lookup_attribute ("visibility", (TYPE_P (*node) 5020 ? TYPE_ATTRIBUTES (*node) 5021 : DECL_ATTRIBUTES (decl)))) 5022 error ("%qD redeclared with different visibility", decl); 5023 5024 DECL_VISIBILITY (decl) = vis; 5025 DECL_VISIBILITY_SPECIFIED (decl) = 1; 5026 5027 /* Go ahead and attach the attribute to the node as well. This is needed 5028 so we can determine whether we have VISIBILITY_DEFAULT because the 5029 visibility was not specified, or because it was explicitly overridden 5030 from the containing scope. */ 5031 5032 return NULL_TREE; 5033} 5034 5035/* Determine the ELF symbol visibility for DECL, which is either a 5036 variable or a function. It is an error to use this function if a 5037 definition of DECL is not available in this translation unit. 5038 Returns true if the final visibility has been determined by this 5039 function; false if the caller is free to make additional 5040 modifications. */ 5041 5042bool 5043c_determine_visibility (tree decl) 5044{ 5045 gcc_assert (TREE_CODE (decl) == VAR_DECL 5046 || TREE_CODE (decl) == FUNCTION_DECL); 5047 5048 /* If the user explicitly specified the visibility with an 5049 attribute, honor that. DECL_VISIBILITY will have been set during 5050 the processing of the attribute. We check for an explicit 5051 attribute, rather than just checking DECL_VISIBILITY_SPECIFIED, 5052 to distinguish the use of an attribute from the use of a "#pragma 5053 GCC visibility push(...)"; in the latter case we still want other 5054 considerations to be able to overrule the #pragma. */ 5055 if (lookup_attribute ("visibility", DECL_ATTRIBUTES (decl))) 5056 return true; 5057 5058 /* Anything that is exported must have default visibility. */ 5059 if (TARGET_DLLIMPORT_DECL_ATTRIBUTES 5060 && lookup_attribute ("dllexport", DECL_ATTRIBUTES (decl))) 5061 { 5062 DECL_VISIBILITY (decl) = VISIBILITY_DEFAULT; 5063 DECL_VISIBILITY_SPECIFIED (decl) = 1; 5064 return true; 5065 } 5066 5067 /* Set default visibility to whatever the user supplied with 5068 visibility_specified depending on #pragma GCC visibility. */ 5069 if (!DECL_VISIBILITY_SPECIFIED (decl)) 5070 { 5071 DECL_VISIBILITY (decl) = default_visibility; 5072 DECL_VISIBILITY_SPECIFIED (decl) = visibility_options.inpragma; 5073 } 5074 return false; 5075} 5076 5077/* Handle an "tls_model" attribute; arguments as in 5078 struct attribute_spec.handler. */ 5079 5080static tree 5081handle_tls_model_attribute (tree *node, tree name, tree args, 5082 int ARG_UNUSED (flags), bool *no_add_attrs) 5083{ 5084 tree id; 5085 tree decl = *node; 5086 enum tls_model kind; 5087 5088 *no_add_attrs = true; 5089 5090 if (!DECL_THREAD_LOCAL_P (decl)) 5091 { 5092 warning (OPT_Wattributes, "%qE attribute ignored", name); 5093 return NULL_TREE; 5094 } 5095 5096 kind = DECL_TLS_MODEL (decl); 5097 id = TREE_VALUE (args); 5098 if (TREE_CODE (id) != STRING_CST) 5099 { 5100 error ("tls_model argument not a string"); 5101 return NULL_TREE; 5102 } 5103 5104 if (!strcmp (TREE_STRING_POINTER (id), "local-exec")) 5105 kind = TLS_MODEL_LOCAL_EXEC; 5106 else if (!strcmp (TREE_STRING_POINTER (id), "initial-exec")) 5107 kind = TLS_MODEL_INITIAL_EXEC; 5108 else if (!strcmp (TREE_STRING_POINTER (id), "local-dynamic")) 5109 kind = optimize ? TLS_MODEL_LOCAL_DYNAMIC : TLS_MODEL_GLOBAL_DYNAMIC; 5110 else if (!strcmp (TREE_STRING_POINTER (id), "global-dynamic")) 5111 kind = TLS_MODEL_GLOBAL_DYNAMIC; 5112 else 5113 error ("tls_model argument must be one of \"local-exec\", \"initial-exec\", \"local-dynamic\" or \"global-dynamic\""); 5114 5115 DECL_TLS_MODEL (decl) = kind; 5116 return NULL_TREE; 5117} 5118 5119/* Handle a "no_instrument_function" attribute; arguments as in 5120 struct attribute_spec.handler. */ 5121 5122static tree 5123handle_no_instrument_function_attribute (tree *node, tree name, 5124 tree ARG_UNUSED (args), 5125 int ARG_UNUSED (flags), 5126 bool *no_add_attrs) 5127{ 5128 tree decl = *node; 5129 5130 if (TREE_CODE (decl) != FUNCTION_DECL) 5131 { 5132 error ("%J%qE attribute applies only to functions", decl, name); 5133 *no_add_attrs = true; 5134 } 5135 else if (DECL_INITIAL (decl)) 5136 { 5137 error ("%Jcan%'t set %qE attribute after definition", decl, name); 5138 *no_add_attrs = true; 5139 } 5140 else 5141 DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (decl) = 1; 5142 5143 return NULL_TREE; 5144} 5145 5146/* Handle a "malloc" attribute; arguments as in 5147 struct attribute_spec.handler. */ 5148 5149static tree 5150handle_malloc_attribute (tree *node, tree name, tree ARG_UNUSED (args), 5151 int ARG_UNUSED (flags), bool *no_add_attrs) 5152{ 5153 if (TREE_CODE (*node) == FUNCTION_DECL 5154 && POINTER_TYPE_P (TREE_TYPE (TREE_TYPE (*node)))) 5155 DECL_IS_MALLOC (*node) = 1; 5156 else 5157 { 5158 warning (OPT_Wattributes, "%qE attribute ignored", name); 5159 *no_add_attrs = true; 5160 } 5161 5162 return NULL_TREE; 5163} 5164 5165/* Handle a "returns_twice" attribute; arguments as in 5166 struct attribute_spec.handler. */ 5167 5168static tree 5169handle_returns_twice_attribute (tree *node, tree name, tree ARG_UNUSED (args), 5170 int ARG_UNUSED (flags), bool *no_add_attrs) 5171{ 5172 if (TREE_CODE (*node) == FUNCTION_DECL) 5173 DECL_IS_RETURNS_TWICE (*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 "no_limit_stack" attribute; arguments as in 5184 struct attribute_spec.handler. */ 5185 5186static tree 5187handle_no_limit_stack_attribute (tree *node, tree name, 5188 tree ARG_UNUSED (args), 5189 int ARG_UNUSED (flags), 5190 bool *no_add_attrs) 5191{ 5192 tree decl = *node; 5193 5194 if (TREE_CODE (decl) != FUNCTION_DECL) 5195 { 5196 error ("%J%qE attribute applies only to functions", decl, name); 5197 *no_add_attrs = true; 5198 } 5199 else if (DECL_INITIAL (decl)) 5200 { 5201 error ("%Jcan%'t set %qE attribute after definition", decl, name); 5202 *no_add_attrs = true; 5203 } 5204 else 5205 DECL_NO_LIMIT_STACK (decl) = 1; 5206 5207 return NULL_TREE; 5208} 5209 5210/* Handle a "pure" attribute; arguments as in 5211 struct attribute_spec.handler. */ 5212 5213static tree 5214handle_pure_attribute (tree *node, tree name, tree ARG_UNUSED (args), 5215 int ARG_UNUSED (flags), bool *no_add_attrs) 5216{ 5217 if (TREE_CODE (*node) == FUNCTION_DECL) 5218 DECL_IS_PURE (*node) = 1; 5219 /* ??? TODO: Support types. */ 5220 else 5221 { 5222 warning (OPT_Wattributes, "%qE attribute ignored", name); 5223 *no_add_attrs = true; 5224 } 5225 5226 return NULL_TREE; 5227} 5228 5229/* Handle a "no vops" attribute; arguments as in 5230 struct attribute_spec.handler. */ 5231 5232static tree 5233handle_novops_attribute (tree *node, tree ARG_UNUSED (name), 5234 tree ARG_UNUSED (args), int ARG_UNUSED (flags), 5235 bool *ARG_UNUSED (no_add_attrs)) 5236{ 5237 gcc_assert (TREE_CODE (*node) == FUNCTION_DECL); 5238 DECL_IS_NOVOPS (*node) = 1; 5239 return NULL_TREE; 5240} 5241 5242/* Handle a "deprecated" attribute; arguments as in 5243 struct attribute_spec.handler. */ 5244 5245static tree 5246handle_deprecated_attribute (tree *node, tree name, 5247 tree ARG_UNUSED (args), int flags, 5248 bool *no_add_attrs) 5249{ 5250 tree type = NULL_TREE; 5251 int warn = 0; 5252 tree what = NULL_TREE; 5253 5254 if (DECL_P (*node)) 5255 { 5256 tree decl = *node; 5257 type = TREE_TYPE (decl); 5258 5259 if (TREE_CODE (decl) == TYPE_DECL 5260 || TREE_CODE (decl) == PARM_DECL 5261 || TREE_CODE (decl) == VAR_DECL 5262 || TREE_CODE (decl) == FUNCTION_DECL 5263 || TREE_CODE (decl) == FIELD_DECL) 5264 TREE_DEPRECATED (decl) = 1; 5265 else 5266 warn = 1; 5267 } 5268 else if (TYPE_P (*node)) 5269 { 5270 if (!(flags & (int) ATTR_FLAG_TYPE_IN_PLACE)) 5271 *node = build_variant_type_copy (*node); 5272 TREE_DEPRECATED (*node) = 1; 5273 type = *node; 5274 } 5275 else 5276 warn = 1; 5277 5278 if (warn) 5279 { 5280 *no_add_attrs = true; 5281 if (type && TYPE_NAME (type)) 5282 { 5283 if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE) 5284 what = TYPE_NAME (*node); 5285 else if (TREE_CODE (TYPE_NAME (type)) == TYPE_DECL 5286 && DECL_NAME (TYPE_NAME (type))) 5287 what = DECL_NAME (TYPE_NAME (type)); 5288 } 5289 if (what) 5290 warning (OPT_Wattributes, "%qE attribute ignored for %qE", name, what); 5291 else 5292 warning (OPT_Wattributes, "%qE attribute ignored", name); 5293 } 5294 5295 return NULL_TREE; 5296} 5297 5298/* Handle a "vector_size" attribute; arguments as in 5299 struct attribute_spec.handler. */ 5300 5301static tree 5302handle_vector_size_attribute (tree *node, tree name, tree args, 5303 int ARG_UNUSED (flags), 5304 bool *no_add_attrs) 5305{ 5306 unsigned HOST_WIDE_INT vecsize, nunits; 5307 enum machine_mode orig_mode; 5308 tree type = *node, new_type, size; 5309 5310 *no_add_attrs = true; 5311 5312 size = TREE_VALUE (args); 5313 5314 if (!host_integerp (size, 1)) 5315 { 5316 warning (OPT_Wattributes, "%qE attribute ignored", name); 5317 return NULL_TREE; 5318 } 5319 5320 /* Get the vector size (in bytes). */ 5321 vecsize = tree_low_cst (size, 1); 5322 5323 /* We need to provide for vector pointers, vector arrays, and 5324 functions returning vectors. For example: 5325 5326 __attribute__((vector_size(16))) short *foo; 5327 5328 In this case, the mode is SI, but the type being modified is 5329 HI, so we need to look further. */ 5330 5331 while (POINTER_TYPE_P (type) 5332 || TREE_CODE (type) == FUNCTION_TYPE 5333 || TREE_CODE (type) == METHOD_TYPE 5334 || TREE_CODE (type) == ARRAY_TYPE) 5335 type = TREE_TYPE (type); 5336 5337 /* Get the mode of the type being modified. */ 5338 orig_mode = TYPE_MODE (type); 5339 5340 if (TREE_CODE (type) == RECORD_TYPE 5341 || TREE_CODE (type) == UNION_TYPE 5342 || TREE_CODE (type) == VECTOR_TYPE 5343 || (!SCALAR_FLOAT_MODE_P (orig_mode) 5344 && GET_MODE_CLASS (orig_mode) != MODE_INT) 5345 || !host_integerp (TYPE_SIZE_UNIT (type), 1)) 5346 { 5347 error ("invalid vector type for attribute %qE", name); 5348 return NULL_TREE; 5349 } 5350 5351 if (vecsize % tree_low_cst (TYPE_SIZE_UNIT (type), 1)) 5352 { 5353 error ("vector size not an integral multiple of component size"); 5354 return NULL; 5355 } 5356 5357 if (vecsize == 0) 5358 { 5359 error ("zero vector size"); 5360 return NULL; 5361 } 5362 5363 /* Calculate how many units fit in the vector. */ 5364 nunits = vecsize / tree_low_cst (TYPE_SIZE_UNIT (type), 1); 5365 if (nunits & (nunits - 1)) 5366 { 5367 error ("number of components of the vector not a power of two"); 5368 return NULL_TREE; 5369 } 5370 5371 new_type = build_vector_type (type, nunits); 5372 5373 /* Build back pointers if needed. */ 5374 *node = reconstruct_complex_type (*node, new_type); 5375 5376 return NULL_TREE; 5377} 5378 5379/* Handle the "nonnull" attribute. */ 5380static tree 5381handle_nonnull_attribute (tree *node, tree ARG_UNUSED (name), 5382 tree args, int ARG_UNUSED (flags), 5383 bool *no_add_attrs) 5384{ 5385 tree type = *node; 5386 unsigned HOST_WIDE_INT attr_arg_num; 5387 5388 /* If no arguments are specified, all pointer arguments should be 5389 non-null. Verify a full prototype is given so that the arguments 5390 will have the correct types when we actually check them later. */ 5391 if (!args) 5392 { 5393 if (!TYPE_ARG_TYPES (type)) 5394 { 5395 error ("nonnull attribute without arguments on a non-prototype"); 5396 *no_add_attrs = true; 5397 } 5398 return NULL_TREE; 5399 } 5400 5401 /* Argument list specified. Verify that each argument number references 5402 a pointer argument. */ 5403 for (attr_arg_num = 1; args; args = TREE_CHAIN (args)) 5404 { 5405 tree argument; 5406 unsigned HOST_WIDE_INT arg_num = 0, ck_num; 5407 5408 if (!get_nonnull_operand (TREE_VALUE (args), &arg_num)) 5409 { 5410 error ("nonnull argument has invalid operand number (argument %lu)", 5411 (unsigned long) attr_arg_num); 5412 *no_add_attrs = true; 5413 return NULL_TREE; 5414 } 5415 5416 argument = TYPE_ARG_TYPES (type); 5417 if (argument) 5418 { 5419 for (ck_num = 1; ; ck_num++) 5420 { 5421 if (!argument || ck_num == arg_num) 5422 break; 5423 argument = TREE_CHAIN (argument); 5424 } 5425 5426 if (!argument 5427 || TREE_CODE (TREE_VALUE (argument)) == VOID_TYPE) 5428 { 5429 error ("nonnull argument with out-of-range operand number (argument %lu, operand %lu)", 5430 (unsigned long) attr_arg_num, (unsigned long) arg_num); 5431 *no_add_attrs = true; 5432 return NULL_TREE; 5433 } 5434 5435 if (TREE_CODE (TREE_VALUE (argument)) != POINTER_TYPE) 5436 { 5437 error ("nonnull argument references non-pointer operand (argument %lu, operand %lu)", 5438 (unsigned long) attr_arg_num, (unsigned long) arg_num); 5439 *no_add_attrs = true; 5440 return NULL_TREE; 5441 } 5442 } 5443 } 5444 5445 return NULL_TREE; 5446} 5447 5448/* Check the argument list of a function call for null in argument slots 5449 that are marked as requiring a non-null pointer argument. */ 5450 5451static void 5452check_function_nonnull (tree attrs, tree params) 5453{ 5454 tree a, args, param; 5455 int param_num; 5456 5457 for (a = attrs; a; a = TREE_CHAIN (a)) 5458 { 5459 if (is_attribute_p ("nonnull", TREE_PURPOSE (a))) 5460 { 5461 args = TREE_VALUE (a); 5462 5463 /* Walk the argument list. If we encounter an argument number we 5464 should check for non-null, do it. If the attribute has no args, 5465 then every pointer argument is checked (in which case the check 5466 for pointer type is done in check_nonnull_arg). */ 5467 for (param = params, param_num = 1; ; 5468 param_num++, param = TREE_CHAIN (param)) 5469 { 5470 if (!param) 5471 break; 5472 if (!args || nonnull_check_p (args, param_num)) 5473 check_function_arguments_recurse (check_nonnull_arg, NULL, 5474 TREE_VALUE (param), 5475 param_num); 5476 } 5477 } 5478 } 5479} 5480 5481/* Check that the Nth argument of a function call (counting backwards 5482 from the end) is a (pointer)0. */ 5483 5484static void 5485check_function_sentinel (tree attrs, tree params, tree typelist) 5486{ 5487 tree attr = lookup_attribute ("sentinel", attrs); 5488 5489 if (attr) 5490 { 5491 /* Skip over the named arguments. */ 5492 while (typelist && params) 5493 { 5494 typelist = TREE_CHAIN (typelist); 5495 params = TREE_CHAIN (params); 5496 } 5497 5498 if (typelist || !params) 5499 warning (OPT_Wformat, 5500 "not enough variable arguments to fit a sentinel"); 5501 else 5502 { 5503 tree sentinel, end; 5504 unsigned pos = 0; 5505 5506 if (TREE_VALUE (attr)) 5507 { 5508 tree p = TREE_VALUE (TREE_VALUE (attr)); 5509 pos = TREE_INT_CST_LOW (p); 5510 } 5511 5512 sentinel = end = params; 5513 5514 /* Advance `end' ahead of `sentinel' by `pos' positions. */ 5515 while (pos > 0 && TREE_CHAIN (end)) 5516 { 5517 pos--; 5518 end = TREE_CHAIN (end); 5519 } 5520 if (pos > 0) 5521 { 5522 warning (OPT_Wformat, 5523 "not enough variable arguments to fit a sentinel"); 5524 return; 5525 } 5526 5527 /* Now advance both until we find the last parameter. */ 5528 while (TREE_CHAIN (end)) 5529 { 5530 end = TREE_CHAIN (end); 5531 sentinel = TREE_CHAIN (sentinel); 5532 } 5533 5534 /* Validate the sentinel. */ 5535 if ((!POINTER_TYPE_P (TREE_TYPE (TREE_VALUE (sentinel))) 5536 || !integer_zerop (TREE_VALUE (sentinel))) 5537 /* Although __null (in C++) is only an integer we allow it 5538 nevertheless, as we are guaranteed that it's exactly 5539 as wide as a pointer, and we don't want to force 5540 users to cast the NULL they have written there. 5541 We warn with -Wstrict-null-sentinel, though. */ 5542 && (warn_strict_null_sentinel 5543 || null_node != TREE_VALUE (sentinel))) 5544 warning (OPT_Wformat, "missing sentinel in function call"); 5545 } 5546 } 5547} 5548 5549/* Helper for check_function_nonnull; given a list of operands which 5550 must be non-null in ARGS, determine if operand PARAM_NUM should be 5551 checked. */ 5552 5553static bool 5554nonnull_check_p (tree args, unsigned HOST_WIDE_INT param_num) 5555{ 5556 unsigned HOST_WIDE_INT arg_num = 0; 5557 5558 for (; args; args = TREE_CHAIN (args)) 5559 { 5560 bool found = get_nonnull_operand (TREE_VALUE (args), &arg_num); 5561 5562 gcc_assert (found); 5563 5564 if (arg_num == param_num) 5565 return true; 5566 } 5567 return false; 5568} 5569 5570/* Check that the function argument PARAM (which is operand number 5571 PARAM_NUM) is non-null. This is called by check_function_nonnull 5572 via check_function_arguments_recurse. */ 5573 5574static void 5575check_nonnull_arg (void * ARG_UNUSED (ctx), tree param, 5576 unsigned HOST_WIDE_INT param_num) 5577{ 5578 /* Just skip checking the argument if it's not a pointer. This can 5579 happen if the "nonnull" attribute was given without an operand 5580 list (which means to check every pointer argument). */ 5581 5582 if (TREE_CODE (TREE_TYPE (param)) != POINTER_TYPE) 5583 return; 5584 5585 if (integer_zerop (param)) 5586 warning (OPT_Wnonnull, "null argument where non-null required " 5587 "(argument %lu)", (unsigned long) param_num); 5588} 5589 5590/* Helper for nonnull attribute handling; fetch the operand number 5591 from the attribute argument list. */ 5592 5593static bool 5594get_nonnull_operand (tree arg_num_expr, unsigned HOST_WIDE_INT *valp) 5595{ 5596 /* Verify the arg number is a constant. */ 5597 if (TREE_CODE (arg_num_expr) != INTEGER_CST 5598 || TREE_INT_CST_HIGH (arg_num_expr) != 0) 5599 return false; 5600 5601 *valp = TREE_INT_CST_LOW (arg_num_expr); 5602 return true; 5603} 5604 5605/* Handle a "nothrow" attribute; arguments as in 5606 struct attribute_spec.handler. */ 5607 5608static tree 5609handle_nothrow_attribute (tree *node, tree name, tree ARG_UNUSED (args), 5610 int ARG_UNUSED (flags), bool *no_add_attrs) 5611{ 5612 if (TREE_CODE (*node) == FUNCTION_DECL) 5613 TREE_NOTHROW (*node) = 1; 5614 /* ??? TODO: Support types. */ 5615 else 5616 { 5617 warning (OPT_Wattributes, "%qE attribute ignored", name); 5618 *no_add_attrs = true; 5619 } 5620 5621 return NULL_TREE; 5622} 5623 5624/* Handle a "cleanup" attribute; arguments as in 5625 struct attribute_spec.handler. */ 5626 5627static tree 5628handle_cleanup_attribute (tree *node, tree name, tree args, 5629 int ARG_UNUSED (flags), bool *no_add_attrs) 5630{ 5631 tree decl = *node; 5632 tree cleanup_id, cleanup_decl; 5633 5634 /* ??? Could perhaps support cleanups on TREE_STATIC, much like we do 5635 for global destructors in C++. This requires infrastructure that 5636 we don't have generically at the moment. It's also not a feature 5637 we'd be missing too much, since we do have attribute constructor. */ 5638 if (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl)) 5639 { 5640 warning (OPT_Wattributes, "%qE attribute ignored", name); 5641 *no_add_attrs = true; 5642 return NULL_TREE; 5643 } 5644 5645 /* Verify that the argument is a function in scope. */ 5646 /* ??? We could support pointers to functions here as well, if 5647 that was considered desirable. */ 5648 cleanup_id = TREE_VALUE (args); 5649 if (TREE_CODE (cleanup_id) != IDENTIFIER_NODE) 5650 { 5651 error ("cleanup argument not an identifier"); 5652 *no_add_attrs = true; 5653 return NULL_TREE; 5654 } 5655 cleanup_decl = lookup_name (cleanup_id); 5656 if (!cleanup_decl || TREE_CODE (cleanup_decl) != FUNCTION_DECL) 5657 { 5658 error ("cleanup argument not a function"); 5659 *no_add_attrs = true; 5660 return NULL_TREE; 5661 } 5662 5663 /* That the function has proper type is checked with the 5664 eventual call to build_function_call. */ 5665 5666 return NULL_TREE; 5667} 5668 5669/* Handle a "warn_unused_result" attribute. No special handling. */ 5670 5671static tree 5672handle_warn_unused_result_attribute (tree *node, tree name, 5673 tree ARG_UNUSED (args), 5674 int ARG_UNUSED (flags), bool *no_add_attrs) 5675{ 5676 /* Ignore the attribute for functions not returning any value. */ 5677 if (VOID_TYPE_P (TREE_TYPE (*node))) 5678 { 5679 warning (OPT_Wattributes, "%qE attribute ignored", name); 5680 *no_add_attrs = true; 5681 } 5682 5683 return NULL_TREE; 5684} 5685 5686/* Handle a "sentinel" attribute. */ 5687 5688static tree 5689handle_sentinel_attribute (tree *node, tree name, tree args, 5690 int ARG_UNUSED (flags), bool *no_add_attrs) 5691{ 5692 tree params = TYPE_ARG_TYPES (*node); 5693 5694 if (!params) 5695 { 5696 warning (OPT_Wattributes, 5697 "%qE attribute requires prototypes with named arguments", name); 5698 *no_add_attrs = true; 5699 } 5700 else 5701 { 5702 while (TREE_CHAIN (params)) 5703 params = TREE_CHAIN (params); 5704 5705 if (VOID_TYPE_P (TREE_VALUE (params))) 5706 { 5707 warning (OPT_Wattributes, 5708 "%qE attribute only applies to variadic functions", name); 5709 *no_add_attrs = true; 5710 } 5711 } 5712 5713 if (args) 5714 { 5715 tree position = TREE_VALUE (args); 5716 5717 if (TREE_CODE (position) != INTEGER_CST) 5718 { 5719 warning (0, "requested position is not an integer constant"); 5720 *no_add_attrs = true; 5721 } 5722 else 5723 { 5724 if (tree_int_cst_lt (position, integer_zero_node)) 5725 { 5726 warning (0, "requested position is less than zero"); 5727 *no_add_attrs = true; 5728 } 5729 } 5730 } 5731 5732 return NULL_TREE; 5733} 5734 5735/* Check for valid arguments being passed to a function. */ 5736void 5737check_function_arguments (tree attrs, tree params, tree typelist) 5738{ 5739 /* Check for null being passed in a pointer argument that must be 5740 non-null. We also need to do this if format checking is enabled. */ 5741 5742 if (warn_nonnull) 5743 check_function_nonnull (attrs, params); 5744 5745 /* Check for errors in format strings. */ 5746 5747 if (warn_format || warn_missing_format_attribute) 5748 check_function_format (attrs, params); 5749 5750 if (warn_format) 5751 check_function_sentinel (attrs, params, typelist); 5752} 5753 5754/* Generic argument checking recursion routine. PARAM is the argument to 5755 be checked. PARAM_NUM is the number of the argument. CALLBACK is invoked 5756 once the argument is resolved. CTX is context for the callback. */ 5757void 5758check_function_arguments_recurse (void (*callback) 5759 (void *, tree, unsigned HOST_WIDE_INT), 5760 void *ctx, tree param, 5761 unsigned HOST_WIDE_INT param_num) 5762{ 5763 if ((TREE_CODE (param) == NOP_EXPR || TREE_CODE (param) == CONVERT_EXPR) 5764 && (TYPE_PRECISION (TREE_TYPE (param)) 5765 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (param, 0))))) 5766 { 5767 /* Strip coercion. */ 5768 check_function_arguments_recurse (callback, ctx, 5769 TREE_OPERAND (param, 0), param_num); 5770 return; 5771 } 5772 5773 if (TREE_CODE (param) == CALL_EXPR) 5774 { 5775 tree type = TREE_TYPE (TREE_TYPE (TREE_OPERAND (param, 0))); 5776 tree attrs; 5777 bool found_format_arg = false; 5778 5779 /* See if this is a call to a known internationalization function 5780 that modifies a format arg. Such a function may have multiple 5781 format_arg attributes (for example, ngettext). */ 5782 5783 for (attrs = TYPE_ATTRIBUTES (type); 5784 attrs; 5785 attrs = TREE_CHAIN (attrs)) 5786 if (is_attribute_p ("format_arg", TREE_PURPOSE (attrs))) 5787 { 5788 tree inner_args; 5789 tree format_num_expr; 5790 int format_num; 5791 int i; 5792 5793 /* Extract the argument number, which was previously checked 5794 to be valid. */ 5795 format_num_expr = TREE_VALUE (TREE_VALUE (attrs)); 5796 5797 gcc_assert (TREE_CODE (format_num_expr) == INTEGER_CST 5798 && !TREE_INT_CST_HIGH (format_num_expr)); 5799 5800 format_num = TREE_INT_CST_LOW (format_num_expr); 5801 5802 for (inner_args = TREE_OPERAND (param, 1), i = 1; 5803 inner_args != 0; 5804 inner_args = TREE_CHAIN (inner_args), i++) 5805 if (i == format_num) 5806 { 5807 check_function_arguments_recurse (callback, ctx, 5808 TREE_VALUE (inner_args), 5809 param_num); 5810 found_format_arg = true; 5811 break; 5812 } 5813 } 5814 5815 /* If we found a format_arg attribute and did a recursive check, 5816 we are done with checking this argument. Otherwise, we continue 5817 and this will be considered a non-literal. */ 5818 if (found_format_arg) 5819 return; 5820 } 5821 5822 if (TREE_CODE (param) == COND_EXPR) 5823 { 5824 /* Check both halves of the conditional expression. */ 5825 check_function_arguments_recurse (callback, ctx, 5826 TREE_OPERAND (param, 1), param_num); 5827 check_function_arguments_recurse (callback, ctx, 5828 TREE_OPERAND (param, 2), param_num); 5829 return; 5830 } 5831 5832 (*callback) (ctx, param, param_num); 5833} 5834 5835/* Function to help qsort sort FIELD_DECLs by name order. */ 5836 5837int 5838field_decl_cmp (const void *x_p, const void *y_p) 5839{ 5840 const tree *const x = (const tree *const) x_p; 5841 const tree *const y = (const tree *const) y_p; 5842 5843 if (DECL_NAME (*x) == DECL_NAME (*y)) 5844 /* A nontype is "greater" than a type. */ 5845 return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL); 5846 if (DECL_NAME (*x) == NULL_TREE) 5847 return -1; 5848 if (DECL_NAME (*y) == NULL_TREE) 5849 return 1; 5850 if (DECL_NAME (*x) < DECL_NAME (*y)) 5851 return -1; 5852 return 1; 5853} 5854 5855static struct { 5856 gt_pointer_operator new_value; 5857 void *cookie; 5858} resort_data; 5859 5860/* This routine compares two fields like field_decl_cmp but using the 5861pointer operator in resort_data. */ 5862 5863static int 5864resort_field_decl_cmp (const void *x_p, const void *y_p) 5865{ 5866 const tree *const x = (const tree *const) x_p; 5867 const tree *const y = (const tree *const) y_p; 5868 5869 if (DECL_NAME (*x) == DECL_NAME (*y)) 5870 /* A nontype is "greater" than a type. */ 5871 return (TREE_CODE (*y) == TYPE_DECL) - (TREE_CODE (*x) == TYPE_DECL); 5872 if (DECL_NAME (*x) == NULL_TREE) 5873 return -1; 5874 if (DECL_NAME (*y) == NULL_TREE) 5875 return 1; 5876 { 5877 tree d1 = DECL_NAME (*x); 5878 tree d2 = DECL_NAME (*y); 5879 resort_data.new_value (&d1, resort_data.cookie); 5880 resort_data.new_value (&d2, resort_data.cookie); 5881 if (d1 < d2) 5882 return -1; 5883 } 5884 return 1; 5885} 5886 5887/* Resort DECL_SORTED_FIELDS because pointers have been reordered. */ 5888 5889void 5890resort_sorted_fields (void *obj, 5891 void * ARG_UNUSED (orig_obj), 5892 gt_pointer_operator new_value, 5893 void *cookie) 5894{ 5895 struct sorted_fields_type *sf = (struct sorted_fields_type *) obj; 5896 resort_data.new_value = new_value; 5897 resort_data.cookie = cookie; 5898 qsort (&sf->elts[0], sf->len, sizeof (tree), 5899 resort_field_decl_cmp); 5900} 5901 5902/* Subroutine of c_parse_error. 5903 Return the result of concatenating LHS and RHS. RHS is really 5904 a string literal, its first character is indicated by RHS_START and 5905 RHS_SIZE is its length (including the terminating NUL character). 5906 5907 The caller is responsible for deleting the returned pointer. */ 5908 5909static char * 5910catenate_strings (const char *lhs, const char *rhs_start, int rhs_size) 5911{ 5912 const int lhs_size = strlen (lhs); 5913 char *result = XNEWVEC (char, lhs_size + rhs_size); 5914 strncpy (result, lhs, lhs_size); 5915 strncpy (result + lhs_size, rhs_start, rhs_size); 5916 return result; 5917} 5918 5919/* Issue the error given by GMSGID, indicating that it occurred before 5920 TOKEN, which had the associated VALUE. */ 5921 5922void 5923c_parse_error (const char *gmsgid, enum cpp_ttype token, tree value) 5924{ 5925#define catenate_messages(M1, M2) catenate_strings ((M1), (M2), sizeof (M2)) 5926 5927 char *message = NULL; 5928 5929 if (token == CPP_EOF) 5930 message = catenate_messages (gmsgid, " at end of input"); 5931 else if (token == CPP_CHAR || token == CPP_WCHAR) 5932 { 5933 unsigned int val = TREE_INT_CST_LOW (value); 5934 const char *const ell = (token == CPP_CHAR) ? "" : "L"; 5935 if (val <= UCHAR_MAX && ISGRAPH (val)) 5936 message = catenate_messages (gmsgid, " before %s'%c'"); 5937 else 5938 message = catenate_messages (gmsgid, " before %s'\\x%x'"); 5939 5940 error (message, ell, val); 5941 free (message); 5942 message = NULL; 5943 } 5944 else if (token == CPP_STRING || token == CPP_WSTRING) 5945 message = catenate_messages (gmsgid, " before string constant"); 5946 else if (token == CPP_NUMBER) 5947 message = catenate_messages (gmsgid, " before numeric constant"); 5948 else if (token == CPP_NAME) 5949 { 5950 message = catenate_messages (gmsgid, " before %qE"); 5951 error (message, value); 5952 free (message); 5953 message = NULL; 5954 } 5955 else if (token == CPP_PRAGMA) 5956 message = catenate_messages (gmsgid, " before %<#pragma%>"); 5957 else if (token == CPP_PRAGMA_EOL) 5958 message = catenate_messages (gmsgid, " before end of line"); 5959 else if (token < N_TTYPES) 5960 { 5961 message = catenate_messages (gmsgid, " before %qs token"); 5962 error (message, cpp_type2name (token)); 5963 free (message); 5964 message = NULL; 5965 } 5966 else 5967 error (gmsgid); 5968 5969 if (message) 5970 { 5971 error (message); 5972 free (message); 5973 } 5974#undef catenate_messages 5975} 5976 5977/* Walk a gimplified function and warn for functions whose return value is 5978 ignored and attribute((warn_unused_result)) is set. This is done before 5979 inlining, so we don't have to worry about that. */ 5980 5981void 5982c_warn_unused_result (tree *top_p) 5983{ 5984 tree t = *top_p; 5985 tree_stmt_iterator i; 5986 tree fdecl, ftype; 5987 5988 switch (TREE_CODE (t)) 5989 { 5990 case STATEMENT_LIST: 5991 for (i = tsi_start (*top_p); !tsi_end_p (i); tsi_next (&i)) 5992 c_warn_unused_result (tsi_stmt_ptr (i)); 5993 break; 5994 5995 case COND_EXPR: 5996 c_warn_unused_result (&COND_EXPR_THEN (t)); 5997 c_warn_unused_result (&COND_EXPR_ELSE (t)); 5998 break; 5999 case BIND_EXPR: 6000 c_warn_unused_result (&BIND_EXPR_BODY (t)); 6001 break; 6002 case TRY_FINALLY_EXPR: 6003 case TRY_CATCH_EXPR: 6004 c_warn_unused_result (&TREE_OPERAND (t, 0)); 6005 c_warn_unused_result (&TREE_OPERAND (t, 1)); 6006 break; 6007 case CATCH_EXPR: 6008 c_warn_unused_result (&CATCH_BODY (t)); 6009 break; 6010 case EH_FILTER_EXPR: 6011 c_warn_unused_result (&EH_FILTER_FAILURE (t)); 6012 break; 6013 6014 case CALL_EXPR: 6015 if (TREE_USED (t)) 6016 break; 6017 6018 /* This is a naked call, as opposed to a CALL_EXPR nested inside 6019 a MODIFY_EXPR. All calls whose value is ignored should be 6020 represented like this. Look for the attribute. */ 6021 fdecl = get_callee_fndecl (t); 6022 if (fdecl) 6023 ftype = TREE_TYPE (fdecl); 6024 else 6025 { 6026 ftype = TREE_TYPE (TREE_OPERAND (t, 0)); 6027 /* Look past pointer-to-function to the function type itself. */ 6028 ftype = TREE_TYPE (ftype); 6029 } 6030 6031 if (lookup_attribute ("warn_unused_result", TYPE_ATTRIBUTES (ftype))) 6032 { 6033 if (fdecl) 6034 warning (0, "%Hignoring return value of %qD, " 6035 "declared with attribute warn_unused_result", 6036 EXPR_LOCUS (t), fdecl); 6037 else 6038 warning (0, "%Hignoring return value of function " 6039 "declared with attribute warn_unused_result", 6040 EXPR_LOCUS (t)); 6041 } 6042 break; 6043 6044 default: 6045 /* Not a container, not a call, or a call whose value is used. */ 6046 break; 6047 } 6048} 6049 6050/* Convert a character from the host to the target execution character 6051 set. cpplib handles this, mostly. */ 6052 6053HOST_WIDE_INT 6054c_common_to_target_charset (HOST_WIDE_INT c) 6055{ 6056 /* Character constants in GCC proper are sign-extended under -fsigned-char, 6057 zero-extended under -fno-signed-char. cpplib insists that characters 6058 and character constants are always unsigned. Hence we must convert 6059 back and forth. */ 6060 cppchar_t uc = ((cppchar_t)c) & ((((cppchar_t)1) << CHAR_BIT)-1); 6061 6062 uc = cpp_host_to_exec_charset (parse_in, uc); 6063 6064 if (flag_signed_char) 6065 return ((HOST_WIDE_INT)uc) << (HOST_BITS_PER_WIDE_INT - CHAR_TYPE_SIZE) 6066 >> (HOST_BITS_PER_WIDE_INT - CHAR_TYPE_SIZE); 6067 else 6068 return uc; 6069} 6070 6071/* Build the result of __builtin_offsetof. EXPR is a nested sequence of 6072 component references, with STOP_REF, or alternatively an INDIRECT_REF of 6073 NULL, at the bottom; much like the traditional rendering of offsetof as a 6074 macro. Returns the folded and properly cast result. */ 6075 6076static tree 6077fold_offsetof_1 (tree expr, tree stop_ref) 6078{ 6079 enum tree_code code = PLUS_EXPR; 6080 tree base, off, t; 6081 6082 if (expr == stop_ref && TREE_CODE (expr) != ERROR_MARK) 6083 return size_zero_node; 6084 6085 switch (TREE_CODE (expr)) 6086 { 6087 case ERROR_MARK: 6088 return expr; 6089 6090 case VAR_DECL: 6091 error ("cannot apply %<offsetof%> to static data member %qD", expr); 6092 return error_mark_node; 6093 6094 case CALL_EXPR: 6095 error ("cannot apply %<offsetof%> when %<operator[]%> is overloaded"); 6096 return error_mark_node; 6097 6098 case INTEGER_CST: 6099 gcc_assert (integer_zerop (expr)); 6100 return size_zero_node; 6101 6102 case NOP_EXPR: 6103 case INDIRECT_REF: 6104 base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref); 6105 gcc_assert (base == error_mark_node || base == size_zero_node); 6106 return base; 6107 6108 case COMPONENT_REF: 6109 base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref); 6110 if (base == error_mark_node) 6111 return base; 6112 6113 t = TREE_OPERAND (expr, 1); 6114 if (DECL_C_BIT_FIELD (t)) 6115 { 6116 error ("attempt to take address of bit-field structure " 6117 "member %qD", t); 6118 return error_mark_node; 6119 } 6120 off = size_binop (PLUS_EXPR, DECL_FIELD_OFFSET (t), 6121 size_int (tree_low_cst (DECL_FIELD_BIT_OFFSET (t), 1) 6122 / BITS_PER_UNIT)); 6123 break; 6124 6125 case ARRAY_REF: 6126 base = fold_offsetof_1 (TREE_OPERAND (expr, 0), stop_ref); 6127 if (base == error_mark_node) 6128 return base; 6129 6130 t = TREE_OPERAND (expr, 1); 6131 if (TREE_CODE (t) == INTEGER_CST && tree_int_cst_sgn (t) < 0) 6132 { 6133 code = MINUS_EXPR; 6134 t = fold_build1 (NEGATE_EXPR, TREE_TYPE (t), t); 6135 } 6136 t = convert (sizetype, t); 6137 off = size_binop (MULT_EXPR, TYPE_SIZE_UNIT (TREE_TYPE (expr)), t); 6138 break; 6139 6140 case COMPOUND_EXPR: 6141 /* Handle static members of volatile structs. */ 6142 t = TREE_OPERAND (expr, 1); 6143 gcc_assert (TREE_CODE (t) == VAR_DECL); 6144 return fold_offsetof_1 (t, stop_ref); 6145 6146 default: 6147 gcc_unreachable (); 6148 } 6149 6150 return size_binop (code, base, off); 6151} 6152 6153tree 6154fold_offsetof (tree expr, tree stop_ref) 6155{ 6156 /* Convert back from the internal sizetype to size_t. */ 6157 return convert (size_type_node, fold_offsetof_1 (expr, stop_ref)); 6158} 6159 6160/* Print an error message for an invalid lvalue. USE says 6161 how the lvalue is being used and so selects the error message. */ 6162 6163void 6164lvalue_error (enum lvalue_use use) 6165{ 6166 switch (use) 6167 { 6168 case lv_assign: 6169 error ("lvalue required as left operand of assignment"); 6170 break; 6171 case lv_increment: 6172 error ("lvalue required as increment operand"); 6173 break; 6174 case lv_decrement: 6175 error ("lvalue required as decrement operand"); 6176 break; 6177 case lv_addressof: 6178 error ("lvalue required as unary %<&%> operand"); 6179 break; 6180 case lv_asm: 6181 error ("lvalue required in asm statement"); 6182 break; 6183 default: 6184 gcc_unreachable (); 6185 } 6186} 6187 6188/* *PTYPE is an incomplete array. Complete it with a domain based on 6189 INITIAL_VALUE. If INITIAL_VALUE is not present, use 1 if DO_DEFAULT 6190 is true. Return 0 if successful, 1 if INITIAL_VALUE can't be deciphered, 6191 2 if INITIAL_VALUE was NULL, and 3 if INITIAL_VALUE was empty. */ 6192 6193int 6194complete_array_type (tree *ptype, tree initial_value, bool do_default) 6195{ 6196 tree maxindex, type, main_type, elt, unqual_elt; 6197 int failure = 0, quals; 6198 6199 maxindex = size_zero_node; 6200 if (initial_value) 6201 { 6202 if (TREE_CODE (initial_value) == STRING_CST) 6203 { 6204 int eltsize 6205 = int_size_in_bytes (TREE_TYPE (TREE_TYPE (initial_value))); 6206 maxindex = size_int (TREE_STRING_LENGTH (initial_value)/eltsize - 1); 6207 } 6208 else if (TREE_CODE (initial_value) == CONSTRUCTOR) 6209 { 6210 VEC(constructor_elt,gc) *v = CONSTRUCTOR_ELTS (initial_value); 6211 6212 if (VEC_empty (constructor_elt, v)) 6213 { 6214 if (pedantic) 6215 failure = 3; 6216 maxindex = integer_minus_one_node; 6217 } 6218 else 6219 { 6220 tree curindex; 6221 unsigned HOST_WIDE_INT cnt; 6222 constructor_elt *ce; 6223 6224 if (VEC_index (constructor_elt, v, 0)->index) 6225 maxindex = fold_convert (sizetype, 6226 VEC_index (constructor_elt, 6227 v, 0)->index); 6228 curindex = maxindex; 6229 6230 for (cnt = 1; 6231 VEC_iterate (constructor_elt, v, cnt, ce); 6232 cnt++) 6233 { 6234 if (ce->index) 6235 curindex = fold_convert (sizetype, ce->index); 6236 else 6237 curindex = size_binop (PLUS_EXPR, curindex, size_one_node); 6238 6239 if (tree_int_cst_lt (maxindex, curindex)) 6240 maxindex = curindex; 6241 } 6242 } 6243 } 6244 else 6245 { 6246 /* Make an error message unless that happened already. */ 6247 if (initial_value != error_mark_node) 6248 failure = 1; 6249 } 6250 } 6251 else 6252 { 6253 failure = 2; 6254 if (!do_default) 6255 return failure; 6256 } 6257 6258 type = *ptype; 6259 elt = TREE_TYPE (type); 6260 quals = TYPE_QUALS (strip_array_types (elt)); 6261 if (quals == 0) 6262 unqual_elt = elt; 6263 else 6264 unqual_elt = c_build_qualified_type (elt, TYPE_UNQUALIFIED); 6265 6266 /* Using build_distinct_type_copy and modifying things afterward instead 6267 of using build_array_type to create a new type preserves all of the 6268 TYPE_LANG_FLAG_? bits that the front end may have set. */ 6269 main_type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type)); 6270 TREE_TYPE (main_type) = unqual_elt; 6271 TYPE_DOMAIN (main_type) = build_index_type (maxindex); 6272 layout_type (main_type); 6273 6274 if (quals == 0) 6275 type = main_type; 6276 else 6277 type = c_build_qualified_type (main_type, quals); 6278 6279 *ptype = type; 6280 return failure; 6281} 6282 6283 6284/* Used to help initialize the builtin-types.def table. When a type of 6285 the correct size doesn't exist, use error_mark_node instead of NULL. 6286 The later results in segfaults even when a decl using the type doesn't 6287 get invoked. */ 6288 6289tree 6290builtin_type_for_size (int size, bool unsignedp) 6291{ 6292 tree type = lang_hooks.types.type_for_size (size, unsignedp); 6293 return type ? type : error_mark_node; 6294} 6295 6296/* A helper function for resolve_overloaded_builtin in resolving the 6297 overloaded __sync_ builtins. Returns a positive power of 2 if the 6298 first operand of PARAMS is a pointer to a supported data type. 6299 Returns 0 if an error is encountered. */ 6300 6301static int 6302sync_resolve_size (tree function, tree params) 6303{ 6304 tree type; 6305 int size; 6306 6307 if (params == NULL) 6308 { 6309 error ("too few arguments to function %qE", function); 6310 return 0; 6311 } 6312 6313 type = TREE_TYPE (TREE_VALUE (params)); 6314 if (TREE_CODE (type) != POINTER_TYPE) 6315 goto incompatible; 6316 6317 type = TREE_TYPE (type); 6318 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type)) 6319 goto incompatible; 6320 6321 size = tree_low_cst (TYPE_SIZE_UNIT (type), 1); 6322 if (size == 1 || size == 2 || size == 4 || size == 8 || size == 16) 6323 return size; 6324 6325 incompatible: 6326 error ("incompatible type for argument %d of %qE", 1, function); 6327 return 0; 6328} 6329 6330/* A helper function for resolve_overloaded_builtin. Adds casts to 6331 PARAMS to make arguments match up with those of FUNCTION. Drops 6332 the variadic arguments at the end. Returns false if some error 6333 was encountered; true on success. */ 6334 6335static bool 6336sync_resolve_params (tree orig_function, tree function, tree params) 6337{ 6338 tree arg_types = TYPE_ARG_TYPES (TREE_TYPE (function)); 6339 tree ptype; 6340 int number; 6341 6342 /* We've declared the implementation functions to use "volatile void *" 6343 as the pointer parameter, so we shouldn't get any complaints from the 6344 call to check_function_arguments what ever type the user used. */ 6345 arg_types = TREE_CHAIN (arg_types); 6346 ptype = TREE_TYPE (TREE_TYPE (TREE_VALUE (params))); 6347 number = 2; 6348 6349 /* For the rest of the values, we need to cast these to FTYPE, so that we 6350 don't get warnings for passing pointer types, etc. */ 6351 while (arg_types != void_list_node) 6352 { 6353 tree val; 6354 6355 params = TREE_CHAIN (params); 6356 if (params == NULL) 6357 { 6358 error ("too few arguments to function %qE", orig_function); 6359 return false; 6360 } 6361 6362 /* ??? Ideally for the first conversion we'd use convert_for_assignment 6363 so that we get warnings for anything that doesn't match the pointer 6364 type. This isn't portable across the C and C++ front ends atm. */ 6365 val = TREE_VALUE (params); 6366 val = convert (ptype, val); 6367 val = convert (TREE_VALUE (arg_types), val); 6368 TREE_VALUE (params) = val; 6369 6370 arg_types = TREE_CHAIN (arg_types); 6371 number++; 6372 } 6373 6374 /* The definition of these primitives is variadic, with the remaining 6375 being "an optional list of variables protected by the memory barrier". 6376 No clue what that's supposed to mean, precisely, but we consider all 6377 call-clobbered variables to be protected so we're safe. */ 6378 TREE_CHAIN (params) = NULL; 6379 6380 return true; 6381} 6382 6383/* A helper function for resolve_overloaded_builtin. Adds a cast to 6384 RESULT to make it match the type of the first pointer argument in 6385 PARAMS. */ 6386 6387static tree 6388sync_resolve_return (tree params, tree result) 6389{ 6390 tree ptype = TREE_TYPE (TREE_TYPE (TREE_VALUE (params))); 6391 ptype = TYPE_MAIN_VARIANT (ptype); 6392 return convert (ptype, result); 6393} 6394 6395/* Some builtin functions are placeholders for other expressions. This 6396 function should be called immediately after parsing the call expression 6397 before surrounding code has committed to the type of the expression. 6398 6399 FUNCTION is the DECL that has been invoked; it is known to be a builtin. 6400 PARAMS is the argument list for the call. The return value is non-null 6401 when expansion is complete, and null if normal processing should 6402 continue. */ 6403 6404tree 6405resolve_overloaded_builtin (tree function, tree params) 6406{ 6407 enum built_in_function orig_code = DECL_FUNCTION_CODE (function); 6408 switch (DECL_BUILT_IN_CLASS (function)) 6409 { 6410 case BUILT_IN_NORMAL: 6411 break; 6412 case BUILT_IN_MD: 6413 if (targetm.resolve_overloaded_builtin) 6414 return targetm.resolve_overloaded_builtin (function, params); 6415 else 6416 return NULL_TREE; 6417 default: 6418 return NULL_TREE; 6419 } 6420 6421 /* Handle BUILT_IN_NORMAL here. */ 6422 switch (orig_code) 6423 { 6424 case BUILT_IN_FETCH_AND_ADD_N: 6425 case BUILT_IN_FETCH_AND_SUB_N: 6426 case BUILT_IN_FETCH_AND_OR_N: 6427 case BUILT_IN_FETCH_AND_AND_N: 6428 case BUILT_IN_FETCH_AND_XOR_N: 6429 case BUILT_IN_FETCH_AND_NAND_N: 6430 case BUILT_IN_ADD_AND_FETCH_N: 6431 case BUILT_IN_SUB_AND_FETCH_N: 6432 case BUILT_IN_OR_AND_FETCH_N: 6433 case BUILT_IN_AND_AND_FETCH_N: 6434 case BUILT_IN_XOR_AND_FETCH_N: 6435 case BUILT_IN_NAND_AND_FETCH_N: 6436 case BUILT_IN_BOOL_COMPARE_AND_SWAP_N: 6437 case BUILT_IN_VAL_COMPARE_AND_SWAP_N: 6438 case BUILT_IN_LOCK_TEST_AND_SET_N: 6439 case BUILT_IN_LOCK_RELEASE_N: 6440 { 6441 int n = sync_resolve_size (function, params); 6442 tree new_function, result; 6443 6444 if (n == 0) 6445 return error_mark_node; 6446 6447 new_function = built_in_decls[orig_code + exact_log2 (n) + 1]; 6448 if (!sync_resolve_params (function, new_function, params)) 6449 return error_mark_node; 6450 6451 result = build_function_call (new_function, params); 6452 if (orig_code != BUILT_IN_BOOL_COMPARE_AND_SWAP_N 6453 && orig_code != BUILT_IN_LOCK_RELEASE_N) 6454 result = sync_resolve_return (params, result); 6455 6456 return result; 6457 } 6458 6459 default: 6460 return NULL_TREE; 6461 } 6462} 6463 6464/* Ignoring their sign, return true if two scalar types are the same. */ 6465bool 6466same_scalar_type_ignoring_signedness (tree t1, tree t2) 6467{ 6468 enum tree_code c1 = TREE_CODE (t1), c2 = TREE_CODE (t2); 6469 6470 gcc_assert ((c1 == INTEGER_TYPE || c1 == REAL_TYPE) 6471 && (c2 == INTEGER_TYPE || c2 == REAL_TYPE)); 6472 6473 /* Equality works here because c_common_signed_type uses 6474 TYPE_MAIN_VARIANT. */ 6475 return lang_hooks.types.signed_type (t1) 6476 == lang_hooks.types.signed_type (t2); 6477} 6478 6479/* Check for missing format attributes on function pointers. LTYPE is 6480 the new type or left-hand side type. RTYPE is the old type or 6481 right-hand side type. Returns TRUE if LTYPE is missing the desired 6482 attribute. */ 6483 6484bool 6485check_missing_format_attribute (tree ltype, tree rtype) 6486{ 6487 tree const ttr = TREE_TYPE (rtype), ttl = TREE_TYPE (ltype); 6488 tree ra; 6489 6490 for (ra = TYPE_ATTRIBUTES (ttr); ra; ra = TREE_CHAIN (ra)) 6491 if (is_attribute_p ("format", TREE_PURPOSE (ra))) 6492 break; 6493 if (ra) 6494 { 6495 tree la; 6496 for (la = TYPE_ATTRIBUTES (ttl); la; la = TREE_CHAIN (la)) 6497 if (is_attribute_p ("format", TREE_PURPOSE (la))) 6498 break; 6499 return !la; 6500 } 6501 else 6502 return false; 6503} 6504 6505/* Subscripting with type char is likely to lose on a machine where 6506 chars are signed. So warn on any machine, but optionally. Don't 6507 warn for unsigned char since that type is safe. Don't warn for 6508 signed char because anyone who uses that must have done so 6509 deliberately. Furthermore, we reduce the false positive load by 6510 warning only for non-constant value of type char. */ 6511 6512void 6513warn_array_subscript_with_type_char (tree index) 6514{ 6515 if (TYPE_MAIN_VARIANT (TREE_TYPE (index)) == char_type_node 6516 && TREE_CODE (index) != INTEGER_CST) 6517 warning (OPT_Wchar_subscripts, "array subscript has type %<char%>"); 6518} 6519 6520/* Implement -Wparentheses for the unexpected C precedence rules, to 6521 cover cases like x + y << z which readers are likely to 6522 misinterpret. We have seen an expression in which CODE is a binary 6523 operator used to combine expressions headed by CODE_LEFT and 6524 CODE_RIGHT. CODE_LEFT and CODE_RIGHT may be ERROR_MARK, which 6525 means that that side of the expression was not formed using a 6526 binary operator, or it was enclosed in parentheses. */ 6527 6528void 6529warn_about_parentheses (enum tree_code code, enum tree_code code_left, 6530 enum tree_code code_right) 6531{ 6532 if (!warn_parentheses) 6533 return; 6534 6535 if (code == LSHIFT_EXPR || code == RSHIFT_EXPR) 6536 { 6537 if (code_left == PLUS_EXPR || code_left == MINUS_EXPR 6538 || code_right == PLUS_EXPR || code_right == MINUS_EXPR) 6539 warning (OPT_Wparentheses, 6540 "suggest parentheses around + or - inside shift"); 6541 } 6542 6543 if (code == TRUTH_ORIF_EXPR) 6544 { 6545 if (code_left == TRUTH_ANDIF_EXPR 6546 || code_right == TRUTH_ANDIF_EXPR) 6547 warning (OPT_Wparentheses, 6548 "suggest parentheses around && within ||"); 6549 } 6550 6551 if (code == BIT_IOR_EXPR) 6552 { 6553 if (code_left == BIT_AND_EXPR || code_left == BIT_XOR_EXPR 6554 || code_left == PLUS_EXPR || code_left == MINUS_EXPR 6555 || code_right == BIT_AND_EXPR || code_right == BIT_XOR_EXPR 6556 || code_right == PLUS_EXPR || code_right == MINUS_EXPR) 6557 warning (OPT_Wparentheses, 6558 "suggest parentheses around arithmetic in operand of |"); 6559 /* Check cases like x|y==z */ 6560 if (TREE_CODE_CLASS (code_left) == tcc_comparison 6561 || TREE_CODE_CLASS (code_right) == tcc_comparison) 6562 warning (OPT_Wparentheses, 6563 "suggest parentheses around comparison in operand of |"); 6564 } 6565 6566 if (code == BIT_XOR_EXPR) 6567 { 6568 if (code_left == BIT_AND_EXPR 6569 || code_left == PLUS_EXPR || code_left == MINUS_EXPR 6570 || code_right == BIT_AND_EXPR 6571 || code_right == PLUS_EXPR || code_right == MINUS_EXPR) 6572 warning (OPT_Wparentheses, 6573 "suggest parentheses around arithmetic in operand of ^"); 6574 /* Check cases like x^y==z */ 6575 if (TREE_CODE_CLASS (code_left) == tcc_comparison 6576 || TREE_CODE_CLASS (code_right) == tcc_comparison) 6577 warning (OPT_Wparentheses, 6578 "suggest parentheses around comparison in operand of ^"); 6579 } 6580 6581 if (code == BIT_AND_EXPR) 6582 { 6583 if (code_left == PLUS_EXPR || code_left == MINUS_EXPR 6584 || code_right == PLUS_EXPR || code_right == MINUS_EXPR) 6585 warning (OPT_Wparentheses, 6586 "suggest parentheses around + or - in operand of &"); 6587 /* Check cases like x&y==z */ 6588 if (TREE_CODE_CLASS (code_left) == tcc_comparison 6589 || TREE_CODE_CLASS (code_right) == tcc_comparison) 6590 warning (OPT_Wparentheses, 6591 "suggest parentheses around comparison in operand of &"); 6592 } 6593 6594 /* Similarly, check for cases like 1<=i<=10 that are probably errors. */ 6595 if (TREE_CODE_CLASS (code) == tcc_comparison 6596 && (TREE_CODE_CLASS (code_left) == tcc_comparison 6597 || TREE_CODE_CLASS (code_right) == tcc_comparison)) 6598 warning (OPT_Wparentheses, "comparisons like X<=Y<=Z do not " 6599 "have their mathematical meaning"); 6600} 6601 6602 6603#include "gt-c-common.h" 6604