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 sequence of declaration specifiers in C.  */
 145 struct c_declspecs {
 146   /* The type specified, not reflecting modifiers such as "short" and
 147      "unsigned", or NULL_TREE if none.  */
 148   tree type;
 149   /* The attributes from a typedef decl.  */
 150   tree decl_attr;
 151   /* When parsing, the attributes.  Outside the parser, this will be
 152      NULL; attributes (possibly from multiple lists) will be passed
 153      separately.  */
 154   tree attrs;
 155   /* The modifier bits present.  */
 156   int specbits;
 157   /* The storage class specifier, or csc_none if none.  */
 158   enum c_storage_class storage_class;
 159   /* Whether something other than a storage class specifier or
 160      attribute has been seen.  This is used to warn for the
 161      obsolescent usage of storage class specifiers other than at the
 162      start of the list.  (Doing this properly would require function
 163      specifiers to be handled separately from storage class
 164      specifiers.)  */
 165   BOOL_BITFIELD non_sc_seen_p : 1;
 166   /* Whether the type is specified by a typedef.  */
 167   BOOL_BITFIELD typedef_p : 1;
 168   /* Whether the type is specified by a typedef whose type is
 169      explicitly "signed".  */
 170   BOOL_BITFIELD typedef_signed_p : 1;
 171   /* Whether the specifiers include a deprecated typedef.  */
 172   BOOL_BITFIELD deprecated_p : 1;
 173   /* Whether "int" was explicitly specified.  */
 174   BOOL_BITFIELD explicit_int_p : 1;
 175   /* Whether "char" was explicitly specified.  */
 176   BOOL_BITFIELD explicit_char_p : 1;
 177   /* Whether "long" was specified more than once.  */
 178   BOOL_BITFIELD long_long_p : 1;
 179   /* Whether "inline" was specified.  */
 180   BOOL_BITFIELD inline_p : 1;
 181   /* Whether "__thread" was specified.  */
 182   BOOL_BITFIELD thread_p : 1;
 183 };
 184
 185 /* The various kinds of declarators in C.  */
 186 enum c_declarator_kind {
 187   /* An identifier.  */
 188   cdk_id,
 189   /* A function.  */
 190   cdk_function,
 191   /* An array.  */
 192   cdk_array,
 193   /* A pointer.  */
 194   cdk_pointer,
 195   /* Parenthesized declarator with nested attributes.  */
 196   cdk_attrs
 197 };
 198
 199 /* Information about the parameters in a function declarator.  */
 200 struct c_arg_info {
 201   /* A list of parameter decls.  */
 202   tree parms;
 203   /* A list of structure, union and enum tags defined.  */
 204   tree tags;
 205   /* A list of argument types to go in the FUNCTION_TYPE.  */
 206   tree types;
 207   /* A list of non-parameter decls (notably enumeration constants)
 208      defined with the parameters.  */
 209   tree others;
 210 };
 211
 212 /* A declarator.  */
 213 struct c_declarator {
 214   /* The kind of declarator.  */
 215   enum c_declarator_kind kind;
 216   /* Except for cdk_id, the contained declarator.  For cdk_id, NULL.  */
 217   struct c_declarator *declarator;
 218   union {
 219     /* For identifiers, an IDENTIFIER_NODE or NULL_TREE if an abstract
 220        declarator.  */
 221     tree id;
 222     /* For functions.  */
 223     struct c_arg_info *arg_info;
 224     /* For arrays.  */
 225     struct {
 226       /* The array dimension, or NULL for [] and [*].  */
 227       tree dimen;
 228       /* The qualifiers (and attributes, currently ignored) inside [].  */
 229       struct c_declspecs *quals;
 230       /* Whether [static] was used.  */
 231       BOOL_BITFIELD static_p : 1;
 232       /* Whether [*] was used.  */
 233       BOOL_BITFIELD vla_unspec_p : 1;
 234     } array;
 235     /* For pointers, the qualifiers on the pointer type.  */
 236     struct c_declspecs *pointer_quals;
 237     /* For attributes.  */
 238     tree attrs;
 239   } u;
 240 };
 241
 242 /* A type name.  */
 243 struct c_type_name {
 244   /* The declaration specifiers.  */
 245   struct c_declspecs *specs;
 246   /* The declarator.  */
 247   struct c_declarator *declarator;
 248 };
 249
 250 /* A parameter.  */
 251 struct c_parm {
 252   /* The declaration specifiers, minus any prefix attributes.  */
 253   struct c_declspecs *specs;
 254   /* The attributes.  */
 255   tree attrs;
 256   /* The declarator.  */
 257   struct c_declarator *declarator;
 258 };
 259
 260 /* Save and restore the variables in this file and elsewhere
 261    that keep track of the progress of compilation of the current function.
 262    Used for nested functions.  */
 263
 264 struct language_function GTY(())
 265 {
 266   struct c_language_function base;
 267   tree x_break_label;
 268   tree x_cont_label;
 269   struct c_switch * GTY((skip)) x_switch_stack;
 270   struct c_arg_info * GTY((skip)) arg_info;
 271   int returns_value;
 272   int returns_null;
 273   int returns_abnormally;
 274   int warn_about_return_type;
 275   int extern_inline;
 276 };
 277
 278 \f
 279 /* in c-parse.in */
 280 extern void c_parse_init (void);
 281
 282 /* in c-aux-info.c */
 283 extern void gen_aux_info_record (tree, int, int, int);
 284
 285 /* in c-decl.c */
 286 extern struct obstack parser_obstack;
 287 extern tree c_break_label;
 288 extern tree c_cont_label;
 289
 290 extern int global_bindings_p (void);
 291 extern void push_scope (void);
 292 extern tree pop_scope (void);
 293 extern void insert_block (tree);
 294 extern tree pushdecl (tree);
 295 extern void c_expand_body (tree);
 296
 297 extern void c_init_decl_processing (void);
 298 extern void c_dup_lang_specific_decl (tree);
 299 extern void c_print_identifier (FILE *, tree, int);
 300 extern struct c_declarator *build_array_declarator (tree, struct c_declspecs *,
 301                                                     bool, bool);
 302 extern tree build_enumerator (tree, tree);
 303 extern void check_for_loop_decls (void);
 304 extern void mark_forward_parm_decls (void);
 305 extern int  complete_array_type (tree, tree, int);
 306 extern void declare_parm_level (void);
 307 extern void undeclared_variable (tree);
 308 extern tree declare_label (tree);
 309 extern tree define_label (location_t, tree);
 310 extern void finish_decl (tree, tree, tree);
 311 extern tree finish_enum (tree, tree, tree);
 312 extern void finish_function (void);
 313 extern tree finish_struct (tree, tree, tree);
 314 extern struct c_arg_info *get_parm_info (bool);
 315 extern tree grokfield (struct c_declarator *, struct c_declspecs *, tree);
 316 extern tree groktypename (struct c_type_name *);
 317 extern tree grokparm (const struct c_parm *);
 318 extern tree implicitly_declare (tree);
 319 extern void keep_next_level (void);
 320 extern tree lookup_name (tree);
 321 extern void pending_xref_error (void);
 322 extern void c_push_function_context (struct function *);
 323 extern void c_pop_function_context (struct function *);
 324 extern void push_parm_decl (const struct c_parm *);
 325 extern tree pushdecl_top_level (tree);
 326 extern struct c_declarator *set_array_declarator_inner (struct c_declarator *,
 327                                                         struct c_declarator *,
 328                                                         bool);
 329 extern tree builtin_function (const char *, tree, int, enum built_in_class,
 330                               const char *, tree);
 331 extern void shadow_tag (const struct c_declspecs *);
 332 extern void shadow_tag_warned (const struct c_declspecs *, int);
 333 extern tree start_enum (tree);
 334 extern int  start_function (struct c_declspecs *, struct c_declarator *, tree);
 335 extern tree start_decl (struct c_declarator *, struct c_declspecs *, bool,
 336                         tree);
 337 extern tree start_struct (enum tree_code, tree);
 338 extern void store_parm_decls (void);
 339 extern void store_parm_decls_from (struct c_arg_info *);
 340 extern tree xref_tag (enum tree_code, tree);
 341 extern int c_expand_decl (tree);
 342 extern struct c_parm *build_c_parm (struct c_declspecs *, tree,
 343                                     struct c_declarator *);
 344 extern struct c_declarator *build_attrs_declarator (tree,
 345                                                     struct c_declarator *);
 346 extern struct c_declarator *build_function_declarator (struct c_arg_info *,
 347                                                        struct c_declarator *);
 348 extern struct c_declarator *build_id_declarator (tree);
 349 extern struct c_declarator *make_pointer_declarator (struct c_declspecs *,
 350                                                      struct c_declarator *);
 351 extern struct c_declspecs *build_null_declspecs (void);
 352 extern struct c_declspecs *declspecs_add_qual (struct c_declspecs *, tree);
 353 extern struct c_declspecs *declspecs_add_type (struct c_declspecs *, tree);
 354 extern struct c_declspecs *declspecs_add_scspec (struct c_declspecs *, tree);
 355 extern struct c_declspecs *declspecs_add_attrs (struct c_declspecs *, tree);
 356
 357 /* in c-objc-common.c */
 358 extern int c_disregard_inline_limits (tree);
 359 extern int c_cannot_inline_tree_fn (tree *);
 360 extern bool c_objc_common_init (void);
 361 extern bool c_missing_noreturn_ok_p (tree);
 362 extern tree c_objc_common_truthvalue_conversion (tree expr);
 363 extern int defer_fn (tree);
 364 extern bool c_warn_unused_global_decl (tree);
 365 extern void c_initialize_diagnostics (diagnostic_context *);
 366
 367 #define c_build_type_variant(TYPE, CONST_P, VOLATILE_P)           \
 368   c_build_qualified_type ((TYPE),                                 \
 369                           ((CONST_P) ? TYPE_QUAL_CONST : 0) |     \
 370                           ((VOLATILE_P) ? TYPE_QUAL_VOLATILE : 0))
 371
 372 /* in c-typeck.c */
 373 extern int in_alignof;
 374 extern int in_sizeof;
 375 extern int in_typeof;
 376
 377 extern struct c_switch *c_switch_stack;
 378
 379 extern tree require_complete_type (tree);
 380 extern int same_translation_unit_p (tree, tree);
 381 extern int comptypes (tree, tree);
 382 extern tree c_size_in_bytes (tree);
 383 extern bool c_mark_addressable (tree);
 384 extern void c_incomplete_type_error (tree, tree);
 385 extern tree c_type_promotes_to (tree);
 386 extern tree composite_type (tree, tree);
 387 extern tree build_component_ref (tree, tree);
 388 extern tree build_indirect_ref (tree, const char *);
 389 extern tree build_array_ref (tree, tree);
 390 extern tree build_external_ref (tree, int);
 391 extern void record_maybe_used_decl (tree);
 392 extern void pop_maybe_used (bool);
 393 extern struct c_expr c_expr_sizeof_expr (struct c_expr);
 394 extern struct c_expr c_expr_sizeof_type (struct c_type_name *);
 395 extern struct c_expr parser_build_binary_op (enum tree_code, struct c_expr,
 396                                              struct c_expr);
 397 extern void readonly_error (tree, const char *);
 398 extern tree build_conditional_expr (tree, tree, tree);
 399 extern tree build_compound_expr (tree, tree);
 400 extern tree c_cast_expr (struct c_type_name *, tree);
 401 extern tree build_c_cast (tree, tree);
 402 extern tree build_modify_expr (tree, enum tree_code, tree);
 403 extern void store_init_value (tree, tree);
 404 extern void error_init (const char *);
 405 extern void pedwarn_init (const char *);
 406 extern void maybe_warn_string_init (tree, struct c_expr);
 407 extern void start_init (tree, tree, int);
 408 extern void finish_init (void);
 409 extern void really_start_incremental_init (tree);
 410 extern void push_init_level (int);
 411 extern struct c_expr pop_init_level (int);
 412 extern void set_init_index (tree, tree);
 413 extern void set_init_label (tree);
 414 extern void process_init_element (struct c_expr);
 415 extern tree build_compound_literal (tree, tree);
 416 extern tree c_start_case (tree);
 417 extern void c_finish_case (tree);
 418 extern tree build_asm_expr (tree, tree, tree, tree, bool);
 419 extern tree build_asm_stmt (tree, tree);
 420 extern tree c_convert_parm_for_inlining (tree, tree, tree, int);
 421 extern int c_types_compatible_p (tree, tree);
 422 extern tree c_begin_compound_stmt (bool);
 423 extern tree c_end_compound_stmt (tree, bool);
 424 extern void c_finish_if_stmt (location_t, tree, tree, tree, bool);
 425 extern void c_finish_loop (location_t, tree, tree, tree, tree, tree, bool);
 426 extern tree c_begin_stmt_expr (void);
 427 extern tree c_finish_stmt_expr (tree);
 428 extern tree c_process_expr_stmt (tree);
 429 extern tree c_finish_expr_stmt (tree);
 430 extern tree c_finish_return (tree);
 431 extern tree c_finish_bc_stmt (tree *, bool);
 432 extern tree c_finish_goto_label (tree);
 433 extern tree c_finish_goto_ptr (tree);
 434
 435 /* Set to 0 at beginning of a function definition, set to 1 if
 436    a return statement that specifies a return value is seen.  */
 437
 438 extern int current_function_returns_value;
 439
 440 /* Set to 0 at beginning of a function definition, set to 1 if
 441    a return statement with no argument is seen.  */
 442
 443 extern int current_function_returns_null;
 444
 445 /* Set to 0 at beginning of a function definition, set to 1 if
 446    a call to a noreturn function is seen.  */
 447
 448 extern int current_function_returns_abnormally;
 449
 450 /* Nonzero means we are reading code that came from a system header file.  */
 451
 452 extern int system_header_p;
 453
 454 /* True means global_bindings_p should return false even if the scope stack
 455    says we are in file scope.  */
 456
 457 extern bool c_override_global_bindings_to_false;
 458
 459 /* True means we've initialized exception handling.  */
 460 extern bool c_eh_initialized_p;
 461
 462 /* In c-decl.c */
 463 extern void c_finish_incomplete_decl (tree);
 464 extern void c_write_global_declarations (void);
 465
 466 /* In order for the format checking to accept the C frontend
 467    diagnostic framework extensions, you must include this file before
 468    toplev.h, not after.  */
 469 #define GCC_DIAG_STYLE __gcc_cdiag__
 470 #if GCC_VERSION >= 3005
 471 #define ATTRIBUTE_GCC_CDIAG(m, n) __attribute__ ((__format__ (GCC_DIAG_STYLE, m ,n))) ATTRIBUTE_NONNULL(m)
 472 #else
 473 #define ATTRIBUTE_GCC_CDIAG(m, n) ATTRIBUTE_NONNULL(m)
 474 #endif
 475
 476 extern void pedwarn_c90 (const char *, ...) ATTRIBUTE_GCC_CDIAG(1,2);
 477 extern void pedwarn_c99 (const char *, ...) ATTRIBUTE_GCC_CDIAG(1,2);
 478
 479 #endif /* ! GCC_C_TREE_H */