gcc/c-tree.h

   1 /* Definitions for C parsing and type checking.
   2    Copyright (C) 1987, 1993, 1994, 1995, 1997, 1998,
   3    1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 2, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING.  If not, write to the Free
  19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  20 02111-1307, USA.  */
  21
  22 #ifndef GCC_C_TREE_H
  23 #define GCC_C_TREE_H
  24
  25 #include "c-common.h"
  26 #include "diagnostic.h"
  27
  28 /* struct lang_identifier is private to c-decl.c, but langhooks.c needs to
  29    know how big it is.  This is sanity-checked in c-decl.c.  */
  30 #define C_SIZEOF_STRUCT_LANG_IDENTIFIER \
  31   (sizeof (struct c_common_identifier) + 3 * sizeof (void *))
  32
  33 /* For gc purposes, return the most likely link for the longest chain.  */
  34 #define C_LANG_TREE_NODE_CHAIN_NEXT(T)                          \
  35   ((union lang_tree_node *)                                     \
  36    (TREE_CODE (T) == INTEGER_TYPE ? TYPE_NEXT_VARIANT (T)       \
  37     : TREE_CODE (T) == COMPOUND_EXPR ? TREE_OPERAND (T, 1)      \
  38     : TREE_CHAIN (T)))
  39
  40 /* Language-specific declaration information.  */
  41
  42 struct lang_decl GTY(())
  43 {
  44   /* The return types and parameter types may have variable size.
  45      This is a list of any SAVE_EXPRs that need to be evaluated to
  46      compute those sizes.  */
  47   tree pending_sizes;
  48 };
  49
  50 /* In a RECORD_TYPE or UNION_TYPE, nonzero if any component is read-only.  */
  51 #define C_TYPE_FIELDS_READONLY(TYPE) TREE_LANG_FLAG_1 (TYPE)
  52
  53 /* In a RECORD_TYPE or UNION_TYPE, nonzero if any component is volatile.  */
  54 #define C_TYPE_FIELDS_VOLATILE(TYPE) TREE_LANG_FLAG_2 (TYPE)
  55
  56 /* In a RECORD_TYPE or UNION_TYPE or ENUMERAL_TYPE
  57    nonzero if the definition of the type has already started.  */
  58 #define C_TYPE_BEING_DEFINED(TYPE) TYPE_LANG_FLAG_0 (TYPE)
  59
  60 /* In an incomplete RECORD_TYPE or UNION_TYPE, a list of variable
  61    declarations whose type would be completed by completing that type.  */
  62 #define C_TYPE_INCOMPLETE_VARS(TYPE) TYPE_VFIELD (TYPE)
  63
  64 /* In an IDENTIFIER_NODE, nonzero if this identifier is actually a
  65    keyword.  C_RID_CODE (node) is then the RID_* value of the keyword,
  66    and C_RID_YYCODE is the token number wanted by Yacc.  */
  67 #define C_IS_RESERVED_WORD(ID) TREE_LANG_FLAG_0 (ID)
  68
  69 struct lang_type GTY(())
  70 {
  71   /* In a RECORD_TYPE, a sorted array of the fields of the type.  */
  72   struct sorted_fields_type * GTY ((reorder ("resort_sorted_fields"))) s;
  73   /* In an ENUMERAL_TYPE, the min and max values.  */
  74   tree enum_min;
  75   tree enum_max;
  76 };
  77
  78 /* Record whether a type or decl was written with nonconstant size.
  79    Note that TYPE_SIZE may have simplified to a constant.  */
  80 #define C_TYPE_VARIABLE_SIZE(TYPE) TYPE_LANG_FLAG_1 (TYPE)
  81 #define C_DECL_VARIABLE_SIZE(TYPE) DECL_LANG_FLAG_0 (TYPE)
  82
  83 /* Record whether a typedef for type `int' was actually `signed int'.  */
  84 #define C_TYPEDEF_EXPLICITLY_SIGNED(EXP) DECL_LANG_FLAG_1 (EXP)
  85
  86 /* For a FUNCTION_DECL, nonzero if it was defined without an explicit
  87    return type.  */
  88 #define C_FUNCTION_IMPLICIT_INT(EXP) DECL_LANG_FLAG_1 (EXP)
  89
  90 /* For a FUNCTION_DECL, nonzero if it was an implicit declaration.  */
  91 #define C_DECL_IMPLICIT(EXP) DECL_LANG_FLAG_2 (EXP)
  92
  93 /* For FUNCTION_DECLs, evaluates true if the decl is built-in but has
  94    been declared.  */
  95 #define C_DECL_DECLARED_BUILTIN(EXP) DECL_LANG_FLAG_3 (EXP)
  96
  97 /* Record whether a decl was declared register.  This is strictly a
  98    front-end flag, whereas DECL_REGISTER is used for code generation;
  99    they may differ for structures with volatile fields.  */
 100 #define C_DECL_REGISTER(EXP) DECL_LANG_FLAG_4 (EXP)
 101
 102 /* Record whether a decl was used in an expression anywhere except an
 103    unevaluated operand of sizeof / typeof / alignof.  This is only
 104    used for functions declared static but not defined, though outside
 105    sizeof and typeof it is set for other function decls as well.  */
 106 #define C_DECL_USED(EXP) DECL_LANG_FLAG_5 (EXP)
 107
 108 /* Nonzero for a decl which either doesn't exist or isn't a prototype.
 109    N.B. Could be simplified if all built-in decls had complete prototypes
 110    (but this is presently difficult because some of them need FILE*).  */
 111 #define C_DECL_ISNT_PROTOTYPE(EXP)                      \
 112        (EXP == 0                                        \
 113         || (TYPE_ARG_TYPES (TREE_TYPE (EXP)) == 0       \
 114             && !DECL_BUILT_IN (EXP)))
 115
 116 /* For FUNCTION_TYPE, a hidden list of types of arguments.  The same as
 117    TYPE_ARG_TYPES for functions with prototypes, but created for functions
 118    without prototypes.  */
 119 #define TYPE_ACTUAL_ARG_TYPES(NODE) TYPE_LANG_SLOT_1 (NODE)
 120
 121 /* Record parser information about an expression that is irrelevant
 122    for code generation alongside a tree representing its value.  */
 123 struct c_expr
 124 {
 125   /* The value of the expression.  */
 126   tree value;
 127   /* Record the original binary operator of an expression, which may
 128      have been changed by fold, STRING_CST for unparenthesised string
 129      constants, or ERROR_MARK for other expressions (including
 130      parenthesized expressions).  */
 131   enum tree_code original_code;
 132 };
 133
 134 /* A storage class specifier.  */
 135 enum c_storage_class {
 136   csc_none,
 137   csc_auto,
 138   csc_extern,
 139   csc_register,
 140   csc_static,
 141   csc_typedef
 142 };
 143
 144 /* A type specifier keyword "void", "_Bool", "char", "int", "float",
 145    "double", or none of these.  */
 146 enum c_typespec_keyword {
 147   cts_none,
 148   cts_void,
 149   cts_bool,
 150   cts_char,
 151   cts_int,
 152   cts_float,
 153   cts_double
 154 };
 155
 156 /* A sequence of declaration specifiers in C.  */
 157 struct c_declspecs {
 158   /* The type specified, if a single type specifier such as a struct,
 159      union or enum specifier, typedef name or typeof specifies the
 160      whole type, or NULL_TREE if none or a keyword such as "void" or
 161      "char" is used.  Does not include qualifiers.  */
 162   tree type;
 163   /* The attributes from a typedef decl.  */
 164   tree decl_attr;
 165   /* When parsing, the attributes.  Outside the parser, this will be
 166      NULL; attributes (possibly from multiple lists) will be passed
 167      separately.  */
 168   tree attrs;
 169   /* Any type specifier keyword used such as "int", not reflecting
 170      modifiers such as "short", or cts_none if none.  */
 171   enum c_typespec_keyword typespec_word;
 172   /* The storage class specifier, or csc_none if none.  */
 173   enum c_storage_class storage_class;
 174   /* Whether something other than a storage class specifier or
 175      attribute has been seen.  This is used to warn for the
 176      obsolescent usage of storage class specifiers other than at the
 177      start of the list.  (Doing this properly would require function
 178      specifiers to be handled separately from storage class
 179      specifiers.)  */
 180   BOOL_BITFIELD non_sc_seen_p : 1;
 181   /* Whether the type is specified by a typedef.  */
 182   BOOL_BITFIELD typedef_p : 1;
 183   /* Whether the type is explicitly "signed" or specified by a typedef
 184      whose type is explicitly "signed".  */
 185   BOOL_BITFIELD explicit_signed_p : 1;
 186   /* Whether the specifiers include a deprecated typedef.  */
 187   BOOL_BITFIELD deprecated_p : 1;
 188   /* Whether the type defaulted to "int" because there were no type
 189      specifiers.  */
 190   BOOL_BITFIELD default_int_p;
 191   /* Whether "long" was specified.  */
 192   BOOL_BITFIELD long_p : 1;
 193   /* Whether "long" was specified more than once.  */
 194   BOOL_BITFIELD long_long_p : 1;
 195   /* Whether "short" was specified.  */
 196   BOOL_BITFIELD short_p : 1;
 197   /* Whether "signed" was specified.  */
 198   BOOL_BITFIELD signed_p : 1;
 199   /* Whether "unsigned" was specified.  */
 200   BOOL_BITFIELD unsigned_p : 1;
 201   /* Whether "complex" was specified.  */
 202   BOOL_BITFIELD complex_p : 1;
 203   /* Whether "inline" was specified.  */
 204   BOOL_BITFIELD inline_p : 1;
 205   /* Whether "__thread" was specified.  */
 206   BOOL_BITFIELD thread_p : 1;
 207   /* Whether "const" was specified.  */
 208   BOOL_BITFIELD const_p : 1;
 209   /* Whether "volatile" was specified.  */
 210   BOOL_BITFIELD volatile_p : 1;
 211   /* Whether "restrict" was specified.  */
 212   BOOL_BITFIELD restrict_p : 1;
 213 };
 214
 215 /* The various kinds of declarators in C.  */
 216 enum c_declarator_kind {
 217   /* An identifier.  */
 218   cdk_id,
 219   /* A function.  */
 220   cdk_function,
 221   /* An array.  */
 222   cdk_array,
 223   /* A pointer.  */
 224   cdk_pointer,
 225   /* Parenthesized declarator with nested attributes.  */
 226   cdk_attrs
 227 };
 228
 229 /* Information about the parameters in a function declarator.  */
 230 struct c_arg_info {
 231   /* A list of parameter decls.  */
 232   tree parms;
 233   /* A list of structure, union and enum tags defined.  */
 234   tree tags;
 235   /* A list of argument types to go in the FUNCTION_TYPE.  */
 236   tree types;
 237   /* A list of non-parameter decls (notably enumeration constants)
 238      defined with the parameters.  */
 239   tree others;
 240 };
 241
 242 /* A declarator.  */
 243 struct c_declarator {
 244   /* The kind of declarator.  */
 245   enum c_declarator_kind kind;
 246   /* Except for cdk_id, the contained declarator.  For cdk_id, NULL.  */
 247   struct c_declarator *declarator;
 248   union {
 249     /* For identifiers, an IDENTIFIER_NODE or NULL_TREE if an abstract
 250        declarator.  */
 251     tree id;
 252     /* For functions.  */
 253     struct c_arg_info *arg_info;
 254     /* For arrays.  */
 255     struct {
 256       /* The array dimension, or NULL for [] and [*].  */
 257       tree dimen;
 258       /* The qualifiers inside [].  */
 259       int quals;
 260       /* The attributes (currently ignored) inside [].  */
 261       tree attrs;
 262       /* Whether [static] was used.  */
 263       BOOL_BITFIELD static_p : 1;
 264       /* Whether [*] was used.  */
 265       BOOL_BITFIELD vla_unspec_p : 1;
 266     } array;
 267     /* For pointers, the qualifiers on the pointer type.  */
 268     int pointer_quals;
 269     /* For attributes.  */
 270     tree attrs;
 271   } u;
 272 };
 273
 274 /* A type name.  */
 275 struct c_type_name {
 276   /* The declaration specifiers.  */
 277   struct c_declspecs *specs;
 278   /* The declarator.  */
 279   struct c_declarator *declarator;
 280 };
 281
 282 /* A parameter.  */
 283 struct c_parm {
 284   /* The declaration specifiers, minus any prefix attributes.  */
 285   struct c_declspecs *specs;
 286   /* The attributes.  */
 287   tree attrs;
 288   /* The declarator.  */
 289   struct c_declarator *declarator;
 290 };
 291
 292 /* Save and restore the variables in this file and elsewhere
 293    that keep track of the progress of compilation of the current function.
 294    Used for nested functions.  */
 295
 296 struct language_function GTY(())
 297 {
 298   struct c_language_function base;
 299   tree x_break_label;
 300   tree x_cont_label;
 301   struct c_switch * GTY((skip)) x_switch_stack;
 302   struct c_arg_info * GTY((skip)) arg_info;
 303   int returns_value;
 304   int returns_null;
 305   int returns_abnormally;
 306   int warn_about_return_type;
 307   int extern_inline;
 308 };
 309
 310 \f
 311 /* in c-parse.in */
 312 extern void c_parse_init (void);
 313
 314 /* in c-aux-info.c */
 315 extern void gen_aux_info_record (tree, int, int, int);
 316
 317 /* in c-decl.c */
 318 extern struct obstack parser_obstack;
 319 extern tree c_break_label;
 320 extern tree c_cont_label;
 321
 322 extern int global_bindings_p (void);
 323 extern void push_scope (void);
 324 extern tree pop_scope (void);
 325 extern void insert_block (tree);
 326 extern tree pushdecl (tree);
 327 extern void c_expand_body (tree);
 328
 329 extern void c_init_decl_processing (void);
 330 extern void c_dup_lang_specific_decl (tree);
 331 extern void c_print_identifier (FILE *, tree, int);
 332 extern int quals_from_declspecs (const struct c_declspecs *);
 333 extern struct c_declarator *build_array_declarator (tree, struct c_declspecs *,
 334                                                     bool, bool);
 335 extern tree build_enumerator (tree, tree);
 336 extern void check_for_loop_decls (void);
 337 extern void mark_forward_parm_decls (void);
 338 extern int  complete_array_type (tree, tree, int);
 339 extern void declare_parm_level (void);
 340 extern void undeclared_variable (tree);
 341 extern tree declare_label (tree);
 342 extern tree define_label (location_t, tree);
 343 extern void finish_decl (tree, tree, tree);
 344 extern tree finish_enum (tree, tree, tree);
 345 extern void finish_function (void);
 346 extern tree finish_struct (tree, tree, tree);
 347 extern struct c_arg_info *get_parm_info (bool);
 348 extern tree grokfield (struct c_declarator *, struct c_declspecs *, tree);
 349 extern tree groktypename (struct c_type_name *);
 350 extern tree grokparm (const struct c_parm *);
 351 extern tree implicitly_declare (tree);
 352 extern void keep_next_level (void);
 353 extern tree lookup_name (tree);
 354 extern void pending_xref_error (void);
 355 extern void c_push_function_context (struct function *);
 356 extern void c_pop_function_context (struct function *);
 357 extern void push_parm_decl (const struct c_parm *);
 358 extern tree pushdecl_top_level (tree);
 359 extern struct c_declarator *set_array_declarator_inner (struct c_declarator *,
 360                                                         struct c_declarator *,
 361                                                         bool);
 362 extern tree builtin_function (const char *, tree, int, enum built_in_class,
 363                               const char *, tree);
 364 extern void shadow_tag (const struct c_declspecs *);
 365 extern void shadow_tag_warned (const struct c_declspecs *, int);
 366 extern tree start_enum (tree);
 367 extern int  start_function (struct c_declspecs *, struct c_declarator *, tree);
 368 extern tree start_decl (struct c_declarator *, struct c_declspecs *, bool,
 369                         tree);
 370 extern tree start_struct (enum tree_code, tree);
 371 extern void store_parm_decls (void);
 372 extern void store_parm_decls_from (struct c_arg_info *);
 373 extern tree xref_tag (enum tree_code, tree);
 374 extern int c_expand_decl (tree);
 375 extern struct c_parm *build_c_parm (struct c_declspecs *, tree,
 376                                     struct c_declarator *);
 377 extern struct c_declarator *build_attrs_declarator (tree,
 378                                                     struct c_declarator *);
 379 extern struct c_declarator *build_function_declarator (struct c_arg_info *,
 380                                                        struct c_declarator *);
 381 extern struct c_declarator *build_id_declarator (tree);
 382 extern struct c_declarator *make_pointer_declarator (struct c_declspecs *,
 383                                                      struct c_declarator *);
 384 extern struct c_declspecs *build_null_declspecs (void);
 385 extern struct c_declspecs *declspecs_add_qual (struct c_declspecs *, tree);
 386 extern struct c_declspecs *declspecs_add_type (struct c_declspecs *, tree);
 387 extern struct c_declspecs *declspecs_add_scspec (struct c_declspecs *, tree);
 388 extern struct c_declspecs *declspecs_add_attrs (struct c_declspecs *, tree);
 389 extern struct c_declspecs *finish_declspecs (struct c_declspecs *);
 390
 391 /* in c-objc-common.c */
 392 extern int c_disregard_inline_limits (tree);
 393 extern int c_cannot_inline_tree_fn (tree *);
 394 extern bool c_objc_common_init (void);
 395 extern bool c_missing_noreturn_ok_p (tree);
 396 extern tree c_objc_common_truthvalue_conversion (tree expr);
 397 extern int defer_fn (tree);
 398 extern bool c_warn_unused_global_decl (tree);
 399 extern void c_initialize_diagnostics (diagnostic_context *);
 400
 401 #define c_build_type_variant(TYPE, CONST_P, VOLATILE_P)           \
 402   c_build_qualified_type ((TYPE),                                 \
 403                           ((CONST_P) ? TYPE_QUAL_CONST : 0) |     \
 404                           ((VOLATILE_P) ? TYPE_QUAL_VOLATILE : 0))
 405
 406 /* in c-typeck.c */
 407 extern int in_alignof;
 408 extern int in_sizeof;
 409 extern int in_typeof;
 410
 411 extern struct c_switch *c_switch_stack;
 412
 413 extern tree require_complete_type (tree);
 414 extern int same_translation_unit_p (tree, tree);
 415 extern int comptypes (tree, tree);
 416 extern tree c_size_in_bytes (tree);
 417 extern bool c_mark_addressable (tree);
 418 extern void c_incomplete_type_error (tree, tree);
 419 extern tree c_type_promotes_to (tree);
 420 extern tree composite_type (tree, tree);
 421 extern tree build_component_ref (tree, tree);
 422 extern tree build_indirect_ref (tree, const char *);
 423 extern tree build_array_ref (tree, tree);
 424 extern tree build_external_ref (tree, int);
 425 extern void record_maybe_used_decl (tree);
 426 extern void pop_maybe_used (bool);
 427 extern struct c_expr c_expr_sizeof_expr (struct c_expr);
 428 extern struct c_expr c_expr_sizeof_type (struct c_type_name *);
 429 extern struct c_expr parser_build_binary_op (enum tree_code, struct c_expr,
 430                                              struct c_expr);
 431 extern void readonly_error (tree, const char *);
 432 extern tree build_conditional_expr (tree, tree, tree);
 433 extern tree build_compound_expr (tree, tree);
 434 extern tree c_cast_expr (struct c_type_name *, tree);
 435 extern tree build_c_cast (tree, tree);
 436 extern tree build_modify_expr (tree, enum tree_code, tree);
 437 extern void store_init_value (tree, tree);
 438 extern void error_init (const char *);
 439 extern void pedwarn_init (const char *);
 440 extern void maybe_warn_string_init (tree, struct c_expr);
 441 extern void start_init (tree, tree, int);
 442 extern void finish_init (void);
 443 extern void really_start_incremental_init (tree);
 444 extern void push_init_level (int);
 445 extern struct c_expr pop_init_level (int);
 446 extern void set_init_index (tree, tree);
 447 extern void set_init_label (tree);
 448 extern void process_init_element (struct c_expr);
 449 extern tree build_compound_literal (tree, tree);
 450 extern tree c_start_case (tree);
 451 extern void c_finish_case (tree);
 452 extern tree build_asm_expr (tree, tree, tree, tree, bool);
 453 extern tree build_asm_stmt (tree, tree);
 454 extern tree c_convert_parm_for_inlining (tree, tree, tree, int);
 455 extern int c_types_compatible_p (tree, tree);
 456 extern tree c_begin_compound_stmt (bool);
 457 extern tree c_end_compound_stmt (tree, bool);
 458 extern void c_finish_if_stmt (location_t, tree, tree, tree, bool);
 459 extern void c_finish_loop (location_t, tree, tree, tree, tree, tree, bool);
 460 extern tree c_begin_stmt_expr (void);
 461 extern tree c_finish_stmt_expr (tree);
 462 extern tree c_process_expr_stmt (tree);
 463 extern tree c_finish_expr_stmt (tree);
 464 extern tree c_finish_return (tree);
 465 extern tree c_finish_bc_stmt (tree *, bool);
 466 extern tree c_finish_goto_label (tree);
 467 extern tree c_finish_goto_ptr (tree);
 468
 469 /* Set to 0 at beginning of a function definition, set to 1 if
 470    a return statement that specifies a return value is seen.  */
 471
 472 extern int current_function_returns_value;
 473
 474 /* Set to 0 at beginning of a function definition, set to 1 if
 475    a return statement with no argument is seen.  */
 476
 477 extern int current_function_returns_null;
 478
 479 /* Set to 0 at beginning of a function definition, set to 1 if
 480    a call to a noreturn function is seen.  */
 481
 482 extern int current_function_returns_abnormally;
 483
 484 /* Nonzero means we are reading code that came from a system header file.  */
 485
 486 extern int system_header_p;
 487
 488 /* True means global_bindings_p should return false even if the scope stack
 489    says we are in file scope.  */
 490
 491 extern bool c_override_global_bindings_to_false;
 492
 493 /* True means we've initialized exception handling.  */
 494 extern bool c_eh_initialized_p;
 495
 496 /* In c-decl.c */
 497 extern void c_finish_incomplete_decl (tree);
 498 extern void c_write_global_declarations (void);
 499
 500 /* In order for the format checking to accept the C frontend
 501    diagnostic framework extensions, you must include this file before
 502    toplev.h, not after.  */
 503 #define GCC_DIAG_STYLE __gcc_cdiag__
 504 #if GCC_VERSION >= 3005
 505 #define ATTRIBUTE_GCC_CDIAG(m, n) __attribute__ ((__format__ (GCC_DIAG_STYLE, m ,n))) ATTRIBUTE_NONNULL(m)
 506 #else
 507 #define ATTRIBUTE_GCC_CDIAG(m, n) ATTRIBUTE_NONNULL(m)
 508 #endif
 509
 510 extern void pedwarn_c90 (const char *, ...) ATTRIBUTE_GCC_CDIAG(1,2);
 511 extern void pedwarn_c99 (const char *, ...) ATTRIBUTE_GCC_CDIAG(1,2);
 512
 513 #endif /* ! GCC_C_TREE_H */