gcc/c/c-tree.h

   1 /* Definitions for C parsing and type checking.
   2    Copyright (C) 1987-2024 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef GCC_C_TREE_H
  21 #define GCC_C_TREE_H
  22
  23 #include "c-family/c-common.h"
  24 #include "diagnostic.h"
  25
  26 /* struct lang_identifier is private to c-decl.cc, but langhooks.cc needs to
  27    know how big it is.  This is sanity-checked in c-decl.cc.  */
  28 #define C_SIZEOF_STRUCT_LANG_IDENTIFIER \
  29   (sizeof (struct c_common_identifier) + 3 * sizeof (void *))
  30
  31 /* In a RECORD_TYPE or UNION_TYPE, nonzero if any component is read-only.  */
  32 #define C_TYPE_FIELDS_READONLY(TYPE) TREE_LANG_FLAG_1 (TYPE)
  33
  34 /* In a RECORD_TYPE or UNION_TYPE, nonzero if any component is volatile.  */
  35 #define C_TYPE_FIELDS_VOLATILE(TYPE) TREE_LANG_FLAG_2 (TYPE)
  36
  37 /* In a RECORD_TYPE or UNION_TYPE, nonzero if any component is
  38    volatile, restrict-qualified or atomic; that is, has a type not
  39    permitted for a constexpr object.  */
  40 #define C_TYPE_FIELDS_NON_CONSTEXPR(TYPE) TREE_LANG_FLAG_4 (TYPE)
  41
  42 /* In a RECORD_TYPE or UNION_TYPE or ENUMERAL_TYPE
  43    nonzero if the definition of the type has already started.  */
  44 #define C_TYPE_BEING_DEFINED(TYPE) TYPE_LANG_FLAG_0 (TYPE)
  45
  46 /* In an incomplete RECORD_TYPE, UNION_TYPE or ENUMERAL_TYPE, a list of
  47    variable declarations whose type would be completed by completing
  48    that type.  */
  49 #define C_TYPE_INCOMPLETE_VARS(TYPE) \
  50   TYPE_LANG_SLOT_1 (TREE_CHECK4 (TYPE, RECORD_TYPE, UNION_TYPE, \
  51                                  QUAL_UNION_TYPE, ENUMERAL_TYPE))
  52
  53 /* In an IDENTIFIER_NODE, nonzero if this identifier is actually a
  54    keyword.  C_RID_CODE (node) is then the RID_* value of the keyword.  */
  55 #define C_IS_RESERVED_WORD(ID) TREE_LANG_FLAG_0 (ID)
  56
  57 /* Record whether a type or decl was written with nonconstant size.
  58    Note that TYPE_SIZE may have simplified to a constant.  */
  59 #define C_TYPE_VARIABLE_SIZE(TYPE) TYPE_LANG_FLAG_1 (TYPE)
  60 #define C_DECL_VARIABLE_SIZE(TYPE) DECL_LANG_FLAG_0 (TYPE)
  61
  62 /* Record whether a type is variably modified. */
  63 #define C_TYPE_VARIABLY_MODIFIED(TYPE) TYPE_LANG_FLAG_6 (TYPE)
  64
  65
  66 /* Record whether a type is defined inside a struct or union type.
  67    This is used for -Wc++-compat. */
  68 #define C_TYPE_DEFINED_IN_STRUCT(TYPE) TYPE_LANG_FLAG_2 (TYPE)
  69
  70 /* Record whether a typedef for type `int' was actually `signed int'.  */
  71 #define C_TYPEDEF_EXPLICITLY_SIGNED(EXP) DECL_LANG_FLAG_1 (EXP)
  72
  73 /* For a FUNCTION_DECL, nonzero if it was defined without an explicit
  74    return type.  */
  75 #define C_FUNCTION_IMPLICIT_INT(EXP) DECL_LANG_FLAG_1 (EXP)
  76
  77 /* For a FUNCTION_DECL, nonzero if it was an implicit declaration.  */
  78 #define C_DECL_IMPLICIT(EXP) DECL_LANG_FLAG_2 (EXP)
  79
  80 /* For a PARM_DECL, nonzero if it was declared as an array.  */
  81 #define C_ARRAY_PARAMETER(NODE) DECL_LANG_FLAG_0 (NODE)
  82
  83 /* For FUNCTION_DECLs, evaluates true if the decl is built-in but has
  84    been declared.  */
  85 #define C_DECL_DECLARED_BUILTIN(EXP)            \
  86   DECL_LANG_FLAG_3 (FUNCTION_DECL_CHECK (EXP))
  87
  88 /* For FUNCTION_DECLs, evaluates true if the decl is built-in, has a
  89    built-in prototype and does not have a non-built-in prototype.  */
  90 #define C_DECL_BUILTIN_PROTOTYPE(EXP)           \
  91   DECL_LANG_FLAG_6 (FUNCTION_DECL_CHECK (EXP))
  92
  93 /* Record whether a decl was declared register.  This is strictly a
  94    front-end flag, whereas DECL_REGISTER is used for code generation;
  95    they may differ for structures with volatile fields.  */
  96 #define C_DECL_REGISTER(EXP) DECL_LANG_FLAG_4 (EXP)
  97
  98 /* Record whether a decl was used in an expression anywhere except an
  99    unevaluated operand of sizeof / typeof / alignof.  This is only
 100    used for functions declared static but not defined, though outside
 101    sizeof and typeof it is set for other function decls as well.  */
 102 #define C_DECL_USED(EXP) DECL_LANG_FLAG_5 (FUNCTION_DECL_CHECK (EXP))
 103
 104 /* Record whether a variable has been declared threadprivate by
 105    #pragma omp threadprivate.  */
 106 #define C_DECL_THREADPRIVATE_P(DECL) DECL_LANG_FLAG_3 (VAR_DECL_CHECK (DECL))
 107
 108 /* Set on VAR_DECLs for compound literals.  */
 109 #define C_DECL_COMPOUND_LITERAL_P(DECL) \
 110   DECL_LANG_FLAG_5 (VAR_DECL_CHECK (DECL))
 111
 112 /* Set on decls used as placeholders for a C23 underspecified object
 113    definition.  */
 114 #define C_DECL_UNDERSPECIFIED(DECL) DECL_LANG_FLAG_7 (DECL)
 115
 116 /* Set on VAR_DECLs declared as 'constexpr'.  */
 117 #define C_DECL_DECLARED_CONSTEXPR(DECL) \
 118   DECL_LANG_FLAG_8 (VAR_DECL_CHECK (DECL))
 119
 120 /* Nonzero for a decl which either doesn't exist or isn't a prototype.
 121    N.B. Could be simplified if all built-in decls had complete prototypes
 122    (but this is presently difficult because some of them need FILE*).  */
 123 #define C_DECL_ISNT_PROTOTYPE(EXP)                      \
 124        (EXP == 0                                        \
 125         || (!prototype_p (TREE_TYPE (EXP))      \
 126             && !fndecl_built_in_p (EXP)))
 127
 128 /* For FUNCTION_TYPE, a hidden list of types of arguments.  The same as
 129    TYPE_ARG_TYPES for functions with prototypes, but created for functions
 130    without prototypes.  */
 131 #define TYPE_ACTUAL_ARG_TYPES(NODE) \
 132   TYPE_LANG_SLOT_1 (FUNCTION_TYPE_CHECK (NODE))
 133
 134 /* For a CONSTRUCTOR, whether some initializer contains a
 135    subexpression meaning it is not a constant expression.  */
 136 #define CONSTRUCTOR_NON_CONST(EXPR) TREE_LANG_FLAG_1 (CONSTRUCTOR_CHECK (EXPR))
 137
 138 /* For a SAVE_EXPR, nonzero if the operand of the SAVE_EXPR has already
 139    been folded.  */
 140 #define SAVE_EXPR_FOLDED_P(EXP) TREE_LANG_FLAG_1 (SAVE_EXPR_CHECK (EXP))
 141
 142 /* Whether a type has boolean semantics: either a boolean type or an
 143    enumeration type with a boolean type as its underlying type.  */
 144 #define C_BOOLEAN_TYPE_P(TYPE)                                          \
 145   (TREE_CODE (TYPE) == BOOLEAN_TYPE                                     \
 146    || (TREE_CODE (TYPE) == ENUMERAL_TYPE                                \
 147        && ENUM_UNDERLYING_TYPE (TYPE) != NULL_TREE                      \
 148        && TREE_CODE (ENUM_UNDERLYING_TYPE (TYPE)) == BOOLEAN_TYPE))
 149
 150 /* Record parser information about an expression that is irrelevant
 151    for code generation alongside a tree representing its value.  */
 152 struct c_expr
 153 {
 154   /* The value of the expression.  */
 155   tree value;
 156   /* Record the original unary/binary operator of an expression, which may
 157      have been changed by fold, STRING_CST for unparenthesized string
 158      constants, C_MAYBE_CONST_EXPR for __builtin_constant_p calls
 159      (even if parenthesized), for subexpressions, and for non-constant
 160      initializers, or ERROR_MARK for other expressions (including
 161      parenthesized expressions).  */
 162   enum tree_code original_code;
 163   /* If not NULL, the original type of an expression.  This will
 164      differ from the type of the value field for an enum constant.
 165      The type of an enum constant is a plain integer type, but this
 166      field will be the enum type.  */
 167   tree original_type;
 168
 169   /* The source range of this expression.  This is redundant
 170      for node values that have locations, but not all node kinds
 171      have locations (e.g. constants, and references to params, locals,
 172      etc), so we stash a copy here.  */
 173   source_range src_range;
 174
 175   /* True if this was directly from a decimal constant token.  */
 176   bool m_decimal : 1;
 177
 178   /* Access to the first and last locations within the source spelling
 179      of this expression.  */
 180   location_t get_start () const { return src_range.m_start; }
 181   location_t get_finish () const { return src_range.m_finish; }
 182
 183   location_t get_location () const
 184   {
 185     if (EXPR_HAS_LOCATION (value))
 186       return EXPR_LOCATION (value);
 187     else
 188       return make_location (get_start (), get_start (), get_finish ());
 189   }
 190
 191   /* Set the value to error_mark_node whilst ensuring that src_range
 192      and m_decimal are initialized.  */
 193   void set_error ()
 194   {
 195     value = error_mark_node;
 196     src_range.m_start = UNKNOWN_LOCATION;
 197     src_range.m_finish = UNKNOWN_LOCATION;
 198     m_decimal = 0;
 199   }
 200 };
 201
 202 /* Type alias for struct c_expr. This allows to use the structure
 203    inside the VEC types.  */
 204 typedef struct c_expr c_expr_t;
 205
 206 /* A kind of type specifier.  Note that this information is currently
 207    only used to distinguish tag definitions, tag references and typeof
 208    uses.  */
 209 enum c_typespec_kind {
 210   /* No typespec.  This appears only in struct c_declspec.  */
 211   ctsk_none,
 212   /* A reserved keyword type specifier.  */
 213   ctsk_resword,
 214   /* A reference to a tag, previously declared, such as "struct foo".
 215      This includes where the previous declaration was as a different
 216      kind of tag, in which case this is only valid if shadowing that
 217      tag in an inner scope.  */
 218   ctsk_tagref,
 219   /* Likewise, with standard attributes present in the reference.  */
 220   ctsk_tagref_attrs,
 221   /* A reference to a tag, not previously declared in a visible
 222      scope.  */
 223   ctsk_tagfirstref,
 224   /* Likewise, with standard attributes present in the reference.  */
 225   ctsk_tagfirstref_attrs,
 226   /* A definition of a tag such as "struct foo { int a; }".  */
 227   ctsk_tagdef,
 228   /* A typedef name.  */
 229   ctsk_typedef,
 230   /* An ObjC-specific kind of type specifier.  */
 231   ctsk_objc,
 232   /* A typeof specifier, or _Atomic ( type-name ).  */
 233   ctsk_typeof
 234 };
 235
 236 /* A type specifier: this structure is created in the parser and
 237    passed to declspecs_add_type only.  */
 238 struct c_typespec {
 239   /* What kind of type specifier this is.  */
 240   enum c_typespec_kind kind;
 241   /* Whether the expression has operands suitable for use in constant
 242      expressions.  */
 243   bool expr_const_operands;
 244   /* Whether the type specifier includes an enum type specifier (that
 245      is, ": specifier-qualifier-list" in a declaration using
 246      "enum").  */
 247   bool has_enum_type_specifier;
 248   /* The specifier itself.  */
 249   tree spec;
 250   /* An expression to be evaluated before the type specifier, in the
 251      case of typeof specifiers, or NULL otherwise or if no such
 252      expression is required for a particular typeof specifier.  In
 253      particular, when typeof is applied to an expression of variably
 254      modified type, that expression must be evaluated in order to
 255      determine array sizes that form part of the type, but the
 256      expression itself (as opposed to the array sizes) forms no part
 257      of the type and so needs to be recorded separately.  */
 258   tree expr;
 259 };
 260
 261 /* A storage class specifier.  */
 262 enum c_storage_class {
 263   csc_none,
 264   csc_auto,
 265   csc_extern,
 266   csc_register,
 267   csc_static,
 268   csc_typedef
 269 };
 270
 271 /* A type specifier keyword "void", "_Bool", "char", "int", "float",
 272    "double", "_Decimal32", "_Decimal64", "_Decimal128", "_Fract", "_Accum",
 273    "_BitInt", or none of these.  */
 274 enum c_typespec_keyword {
 275   cts_none,
 276   cts_void,
 277   cts_bool,
 278   cts_char,
 279   cts_int,
 280   cts_float,
 281   cts_int_n,
 282   cts_double,
 283   cts_dfloat32,
 284   cts_dfloat64,
 285   cts_dfloat128,
 286   cts_floatn_nx,
 287   cts_fract,
 288   cts_accum,
 289   cts_bitint,
 290   cts_auto_type
 291 };
 292
 293 /* This enum lists all the possible declarator specifiers, storage
 294    class or attribute that a user can write.  There is at least one
 295    enumerator per possible declarator specifier in the struct
 296    c_declspecs below.
 297
 298    It is used to index the array of declspec locations in struct
 299    c_declspecs.  */
 300 enum c_declspec_word {
 301   cdw_typespec /* A catch-all for a typespec.  */,
 302   cdw_storage_class  /* A catch-all for a storage class */,
 303   cdw_attributes,
 304   cdw_typedef,
 305   cdw_explicit_signed,
 306   cdw_deprecated,
 307   cdw_default_int,
 308   cdw_long,
 309   cdw_long_long,
 310   cdw_short,
 311   cdw_signed,
 312   cdw_unsigned,
 313   cdw_complex,
 314   cdw_inline,
 315   cdw_noreturn,
 316   cdw_thread,
 317   cdw_const,
 318   cdw_volatile,
 319   cdw_restrict,
 320   cdw_atomic,
 321   cdw_saturating,
 322   cdw_alignas,
 323   cdw_address_space,
 324   cdw_gimple,
 325   cdw_rtl,
 326   cdw_number_of_elements /* This one must always be the last
 327                             enumerator.  */
 328 };
 329
 330 enum c_declspec_il {
 331   cdil_none,
 332   cdil_gimple,          /* __GIMPLE  */
 333   cdil_gimple_cfg,      /* __GIMPLE(cfg)  */
 334   cdil_gimple_ssa,      /* __GIMPLE(ssa)  */
 335   cdil_rtl              /* __RTL  */
 336 };
 337
 338 /* A sequence of declaration specifiers in C.  When a new declaration
 339    specifier is added, please update the enum c_declspec_word above
 340    accordingly.  */
 341 struct c_declspecs {
 342   location_t locations[cdw_number_of_elements];
 343   /* The type specified, if a single type specifier such as a struct,
 344      union or enum specifier, typedef name or typeof specifies the
 345      whole type, or NULL_TREE if none or a keyword such as "void" or
 346      "char" is used.  Does not include qualifiers.  */
 347   tree type;
 348   /* Any expression to be evaluated before the type, from a typeof
 349      specifier.  */
 350   tree expr;
 351   /* The attributes from a typedef decl.  */
 352   tree decl_attr;
 353   /* When parsing, the GNU attributes and prefix standard attributes.
 354      Outside the parser, this will be NULL; attributes (possibly from
 355      multiple lists) will be passed separately.  */
 356   tree attrs;
 357   /* When parsing, postfix standard attributes (which appertain to the
 358      type specified by the preceding declaration specifiers, unlike
 359      prefix standard attributes which appertain to the declaration or
 360      declarations as a whole).  */
 361   tree postfix_attrs;
 362   /* The pass to start compiling a __GIMPLE or __RTL function with.  */
 363   char *gimple_or_rtl_pass;
 364   /* ENTRY BB count.  */
 365   profile_count entry_bb_count;
 366   /* The base-2 log of the greatest alignment required by an _Alignas
 367      specifier, in bytes, or -1 if no such specifiers with nonzero
 368      alignment.  */
 369   int align_log;
 370   union {
 371     /* For the __intN declspec, this stores the index into the int_n_*
 372        arrays.  */
 373     int int_n_idx;
 374     /* For the _FloatN and _FloatNx declspec, this stores the index into
 375        the floatn_nx_types array.  */
 376     int floatn_nx_idx;
 377     /* For _BitInt(N) this stores the N.  */
 378     int bitint_prec;
 379   } u;
 380   /* The storage class specifier, or csc_none if none.  */
 381   enum c_storage_class storage_class;
 382   /* Any type specifier keyword used such as "int", not reflecting
 383      modifiers such as "short", or cts_none if none.  */
 384   ENUM_BITFIELD (c_typespec_keyword) typespec_word : 8;
 385   /* The kind of type specifier if one has been seen, ctsk_none
 386      otherwise.  */
 387   ENUM_BITFIELD (c_typespec_kind) typespec_kind : 4;
 388   ENUM_BITFIELD (c_declspec_il) declspec_il : 3;
 389   /* Whether any expressions in typeof specifiers may appear in
 390      constant expressions.  */
 391   BOOL_BITFIELD expr_const_operands : 1;
 392   /* Whether any declaration specifiers have been seen at all.  */
 393   BOOL_BITFIELD declspecs_seen_p : 1;
 394   /* Whether any declaration specifiers other than standard attributes
 395      have been seen at all.  If only standard attributes have been
 396      seen, this is an attribute-declaration.  */
 397   BOOL_BITFIELD non_std_attrs_seen_p : 1;
 398   /* Whether something other than a storage class specifier or
 399      attribute has been seen.  This is used to warn for the
 400      obsolescent usage of storage class specifiers other than at the
 401      start of the list.  (Doing this properly would require function
 402      specifiers to be handled separately from storage class
 403      specifiers.)  */
 404   BOOL_BITFIELD non_sc_seen_p : 1;
 405   /* Whether the type is specified by a typedef or typeof name.  */
 406   BOOL_BITFIELD typedef_p : 1;
 407   /* Whether the type is explicitly "signed" or specified by a typedef
 408      whose type is explicitly "signed".  */
 409   BOOL_BITFIELD explicit_signed_p : 1;
 410   /* Whether the specifiers include a deprecated typedef.  */
 411   BOOL_BITFIELD deprecated_p : 1;
 412   /* Whether the specifiers include an unavailable typedef.  */
 413   BOOL_BITFIELD unavailable_p : 1;
 414   /* Whether the type defaulted to "int" because there were no type
 415      specifiers.  */
 416   BOOL_BITFIELD default_int_p : 1;
 417   /* Whether "long" was specified.  */
 418   BOOL_BITFIELD long_p : 1;
 419   /* Whether "long" was specified more than once.  */
 420   BOOL_BITFIELD long_long_p : 1;
 421   /* Whether "short" was specified.  */
 422   BOOL_BITFIELD short_p : 1;
 423   /* Whether "signed" was specified.  */
 424   BOOL_BITFIELD signed_p : 1;
 425   /* Whether "unsigned" was specified.  */
 426   BOOL_BITFIELD unsigned_p : 1;
 427   /* Whether "complex" was specified.  */
 428   BOOL_BITFIELD complex_p : 1;
 429   /* Whether "inline" was specified.  */
 430   BOOL_BITFIELD inline_p : 1;
 431   /* Whether "_Noreturn" was speciied.  */
 432   BOOL_BITFIELD noreturn_p : 1;
 433   /* Whether "__thread" or "_Thread_local" was specified.  */
 434   BOOL_BITFIELD thread_p : 1;
 435   /* Whether "__thread" rather than "_Thread_local" was specified.  */
 436   BOOL_BITFIELD thread_gnu_p : 1;
 437   /* Whether "const" was specified.  */
 438   BOOL_BITFIELD const_p : 1;
 439   /* Whether "volatile" was specified.  */
 440   BOOL_BITFIELD volatile_p : 1;
 441   /* Whether "restrict" was specified.  */
 442   BOOL_BITFIELD restrict_p : 1;
 443   /* Whether "_Atomic" was specified.  */
 444   BOOL_BITFIELD atomic_p : 1;
 445   /* Whether "_Sat" was specified.  */
 446   BOOL_BITFIELD saturating_p : 1;
 447   /* Whether any alignment specifier (even with zero alignment) was
 448      specified.  */
 449   BOOL_BITFIELD alignas_p : 1;
 450   /* Whether an enum type specifier (": specifier-qualifier-list") was
 451      specified other than in a definition of that enum (if so, this is
 452      invalid unless it is an empty declaration "enum identifier
 453      enum-type-specifier;", but such an empty declaration is valid in
 454      C23 when "enum identifier;" would not be).  */
 455   BOOL_BITFIELD enum_type_specifier_ref_p : 1;
 456   /* Whether "auto" was specified in C23 (or later) mode and means the
 457      type is to be deduced from an initializer, or would mean that if
 458      no type specifier appears later in these declaration
 459      specifiers.  */
 460   BOOL_BITFIELD c23_auto_p : 1;
 461   /* Whether "constexpr" was specified.  */
 462   BOOL_BITFIELD constexpr_p : 1;
 463   /* The address space that the declaration belongs to.  */
 464   addr_space_t address_space;
 465 };
 466
 467 /* The various kinds of declarators in C.  */
 468 enum c_declarator_kind {
 469   /* An identifier.  */
 470   cdk_id,
 471   /* A function.  */
 472   cdk_function,
 473   /* An array.  */
 474   cdk_array,
 475   /* A pointer.  */
 476   cdk_pointer,
 477   /* Parenthesized declarator with nested attributes.  */
 478   cdk_attrs
 479 };
 480
 481 struct c_arg_tag {
 482   /* The argument name.  */
 483   tree id;
 484   /* The type of the argument.  */
 485   tree type;
 486 };
 487
 488
 489 /* Information about the parameters in a function declarator.  */
 490 struct c_arg_info {
 491   /* A list of parameter decls.  */
 492   tree parms;
 493   /* A list of structure, union and enum tags defined.  */
 494   vec<c_arg_tag, va_gc> *tags;
 495   /* A list of argument types to go in the FUNCTION_TYPE.  */
 496   tree types;
 497   /* A list of non-parameter decls (notably enumeration constants)
 498      defined with the parameters.  */
 499   tree others;
 500   /* A compound expression of VLA sizes from the parameters, or NULL.
 501      In a function definition, these are used to ensure that
 502      side-effects in sizes of arrays converted to pointers (such as a
 503      parameter int i[n++]) take place; otherwise, they are
 504      ignored.  */
 505   tree pending_sizes;
 506   /* True when these arguments had [*].  */
 507   BOOL_BITFIELD had_vla_unspec : 1;
 508   /* True when the arguments are a (...) prototype.  */
 509   BOOL_BITFIELD no_named_args_stdarg_p : 1;
 510 };
 511
 512 /* A declarator.  */
 513 struct c_declarator {
 514   /* The kind of declarator.  */
 515   enum c_declarator_kind kind;
 516   location_t id_loc; /* Currently only set for cdk_id, cdk_array. */
 517   /* Except for cdk_id, the contained declarator.  For cdk_id, NULL.  */
 518   struct c_declarator *declarator;
 519   union {
 520     /* For identifiers.  */
 521     struct {
 522       /* An IDENTIFIER_NODE, or NULL_TREE if an abstract
 523          declarator.  */
 524       tree id;
 525       /* Any attributes (which apply to the declaration rather than to
 526          the type described by the outer declarators).  */
 527       tree attrs;
 528     } id;
 529     /* For functions.  */
 530     struct c_arg_info *arg_info;
 531     /* For arrays.  */
 532     struct {
 533       /* The array dimension, or NULL for [] and [*].  */
 534       tree dimen;
 535       /* The qualifiers inside [].  */
 536       int quals;
 537       /* The attributes (currently ignored) inside [].  */
 538       tree attrs;
 539       /* Whether [static] was used.  */
 540       BOOL_BITFIELD static_p : 1;
 541       /* Whether [*] was used.  */
 542       BOOL_BITFIELD vla_unspec_p : 1;
 543     } array;
 544     /* For pointers, the qualifiers on the pointer type.  */
 545     int pointer_quals;
 546     /* For attributes.  */
 547     tree attrs;
 548   } u;
 549 };
 550
 551 /* A type name.  */
 552 struct c_type_name {
 553   /* The declaration specifiers.  */
 554   struct c_declspecs *specs;
 555   /* The declarator.  */
 556   struct c_declarator *declarator;
 557 };
 558
 559 /* A parameter.  */
 560 struct c_parm {
 561   /* The declaration specifiers, minus any prefix attributes.  */
 562   struct c_declspecs *specs;
 563   /* The attributes.  */
 564   tree attrs;
 565   /* The declarator.  */
 566   struct c_declarator *declarator;
 567   /* The location of the parameter.  */
 568   location_t loc;
 569 };
 570
 571 /* Used when parsing an enum.  Initialized by start_enum.  */
 572 struct c_enum_contents
 573 {
 574   /* While defining an enum type, this is 1 plus the last enumerator
 575      constant value.  */
 576   tree enum_next_value;
 577
 578   /* The enumeration type itself.  */
 579   tree enum_type;
 580
 581   /* Nonzero means that there was overflow computing enum_next_value.  */
 582   int enum_overflow;
 583 };
 584
 585 /* A type of reference to a static identifier in an inline
 586    function.  */
 587 enum c_inline_static_type {
 588   /* Identifier with internal linkage used in function that may be an
 589      inline definition (i.e., file-scope static).  */
 590   csi_internal,
 591   /* Modifiable object with static storage duration defined in
 592      function that may be an inline definition (i.e., local
 593      static).  */
 594   csi_modifiable
 595 };
 596
 597 \f
 598 /* in c-parser.cc */
 599 struct c_tree_token_vec;
 600 extern void c_parse_init (void);
 601 extern bool c_keyword_starts_typename (enum rid keyword);
 602
 603 /* in c-aux-info.cc */
 604 extern void gen_aux_info_record (tree, int, int, int);
 605
 606 /* in c-decl.cc */
 607 struct c_spot_bindings;
 608 class c_struct_parse_info;
 609 extern struct obstack parser_obstack;
 610 /* Set to IN_ITERATION_STMT if parsing an iteration-statement,
 611    to IN_OMP_BLOCK if parsing OpenMP structured block and
 612    IN_OMP_FOR if parsing OpenMP loop.  If parsing a switch statement,
 613    this is bitwise ORed with IN_SWITCH_STMT, unless parsing an
 614    iteration-statement, OpenMP block or loop within that switch.  */
 615 #define IN_SWITCH_STMT          1
 616 #define IN_ITERATION_STMT       2
 617 #define IN_OMP_BLOCK            4
 618 #define IN_OMP_FOR              8
 619 #define IN_OBJC_FOREACH         16
 620 extern unsigned char in_statement;
 621
 622 extern bool switch_statement_break_seen_p;
 623
 624 extern bool global_bindings_p (void);
 625 extern tree pushdecl (tree);
 626 extern unsigned int start_underspecified_init (location_t, tree);
 627 extern void finish_underspecified_init (tree, unsigned int);
 628 extern void push_scope (void);
 629 extern tree pop_scope (void);
 630 extern void c_mark_decl_jump_unsafe_in_current_scope ();
 631 extern void c_bindings_start_stmt_expr (struct c_spot_bindings *);
 632 extern void c_bindings_end_stmt_expr (struct c_spot_bindings *);
 633
 634 extern void record_inline_static (location_t, tree, tree,
 635                                   enum c_inline_static_type);
 636 extern void c_init_decl_processing (void);
 637 extern void c_print_identifier (FILE *, tree, int);
 638 extern int quals_from_declspecs (const struct c_declspecs *);
 639 extern struct c_declarator *build_array_declarator (location_t, tree,
 640                                                     struct c_declspecs *,
 641                                                     bool, bool);
 642 extern tree build_enumerator (location_t, location_t, struct c_enum_contents *,
 643                               tree, tree);
 644 extern tree check_for_loop_decls (location_t, bool);
 645 extern void mark_forward_parm_decls (void);
 646 extern void declare_parm_level (void);
 647 extern void undeclared_variable (location_t, tree);
 648 extern tree lookup_label_for_goto (location_t, tree);
 649 extern tree declare_label (tree);
 650 extern tree define_label (location_t, tree);
 651 extern struct c_spot_bindings *c_get_switch_bindings (void);
 652 extern void c_release_switch_bindings (struct c_spot_bindings *);
 653 extern bool c_check_switch_jump_warnings (struct c_spot_bindings *,
 654                                           location_t, location_t);
 655 extern void finish_decl (tree, location_t, tree, tree, tree);
 656 extern tree finish_enum (tree, tree, tree);
 657 extern void finish_function (location_t = input_location);
 658 extern tree finish_struct (location_t, tree, tree, tree,
 659                            class c_struct_parse_info *,
 660                            tree *expr = NULL);
 661 extern tree c_simulate_enum_decl (location_t, const char *,
 662                                   vec<string_int_pair> *);
 663 extern tree c_simulate_record_decl (location_t, const char *,
 664                                     array_slice<const tree>);
 665 extern struct c_arg_info *build_arg_info (void);
 666 extern struct c_arg_info *get_parm_info (bool, tree);
 667 extern tree grokfield (location_t, struct c_declarator *,
 668                        struct c_declspecs *, tree, tree *, tree *);
 669 extern tree groktypename (struct c_type_name *, tree *, bool *);
 670 extern tree grokparm (const struct c_parm *, tree *);
 671 extern tree implicitly_declare (location_t, tree);
 672 extern void keep_next_level (void);
 673 extern void pending_xref_error (void);
 674 extern void c_push_function_context (void);
 675 extern void c_pop_function_context (void);
 676 extern void push_parm_decl (const struct c_parm *, tree *);
 677 extern struct c_declarator *set_array_declarator_inner (struct c_declarator *,
 678                                                         struct c_declarator *);
 679 extern tree c_builtin_function (tree);
 680 extern tree c_builtin_function_ext_scope (tree);
 681 extern tree c_simulate_builtin_function_decl (tree);
 682 extern void c_warn_unused_attributes (tree);
 683 extern tree c_warn_type_attributes (tree);
 684 extern void shadow_tag (const struct c_declspecs *);
 685 extern void shadow_tag_warned (const struct c_declspecs *, int);
 686 extern tree start_enum (location_t, struct c_enum_contents *, tree, tree,
 687                         bool potential_nesting_p);
 688 extern bool start_function (struct c_declspecs *, struct c_declarator *, tree);
 689 extern tree start_decl (struct c_declarator *, struct c_declspecs *, bool,
 690                         tree, bool = true, location_t * = NULL);
 691 extern tree start_struct (location_t, enum tree_code, tree,
 692                           class c_struct_parse_info **);
 693 extern void store_parm_decls (void);
 694 extern void store_parm_decls_from (struct c_arg_info *);
 695 extern void temp_store_parm_decls (tree, tree);
 696 extern void temp_pop_parm_decls (void);
 697 extern tree xref_tag (enum tree_code, tree);
 698 extern struct c_typespec parser_xref_tag (location_t, enum tree_code, tree,
 699                                           bool, tree, bool);
 700 extern struct c_parm *build_c_parm (struct c_declspecs *, tree,
 701                                     struct c_declarator *, location_t);
 702 extern struct c_declarator *build_attrs_declarator (tree,
 703                                                     struct c_declarator *);
 704 extern struct c_declarator *build_function_declarator (struct c_arg_info *,
 705                                                        struct c_declarator *);
 706 extern struct c_declarator *build_id_declarator (tree);
 707 extern struct c_declarator *make_pointer_declarator (struct c_declspecs *,
 708                                                      struct c_declarator *);
 709 extern struct c_declspecs *build_null_declspecs (void);
 710 extern struct c_declspecs *declspecs_add_qual (location_t,
 711                                                struct c_declspecs *, tree);
 712 extern struct c_declspecs *declspecs_add_type (location_t,
 713                                                struct c_declspecs *,
 714                                                struct c_typespec);
 715 extern struct c_declspecs *declspecs_add_scspec (location_t,
 716                                                  struct c_declspecs *, tree);
 717 extern struct c_declspecs *declspecs_add_attrs (location_t,
 718                                                 struct c_declspecs *, tree);
 719 extern struct c_declspecs *declspecs_add_addrspace (location_t,
 720                                                     struct c_declspecs *,
 721                                                     addr_space_t);
 722 extern struct c_declspecs *declspecs_add_alignas (location_t,
 723                                                   struct c_declspecs *, tree);
 724 extern struct c_declspecs *finish_declspecs (struct c_declspecs *);
 725 extern size_t c_tree_size (enum tree_code);
 726
 727 /* in c-objc-common.cc */
 728 extern bool c_objc_common_init (void);
 729 extern bool c_missing_noreturn_ok_p (tree);
 730 extern bool c_warn_unused_global_decl (const_tree);
 731 extern void c_initialize_diagnostics (diagnostic_context *);
 732 extern bool c_var_mod_p (tree x, tree fn);
 733 extern alias_set_type c_get_alias_set (tree);
 734 extern int c_type_dwarf_attribute (const_tree, int);
 735
 736 /* in c-typeck.cc */
 737 extern int in_alignof;
 738 extern int in_sizeof;
 739 extern int in_typeof;
 740 extern bool c_in_omp_for;
 741 extern bool c_omp_array_section_p;
 742
 743 extern tree c_last_sizeof_arg;
 744 extern location_t c_last_sizeof_loc;
 745
 746 extern struct c_switch *c_switch_stack;
 747
 748 extern bool null_pointer_constant_p (const_tree);
 749
 750
 751 inline
 752 bool c_type_variably_modified_p (tree t)
 753 {
 754   return error_mark_node != t && C_TYPE_VARIABLY_MODIFIED (t);
 755 }
 756
 757
 758 extern bool char_type_p (tree);
 759 extern tree c_objc_common_truthvalue_conversion (location_t, tree,
 760                                                  tree = integer_type_node);
 761 extern tree require_complete_type (location_t, tree);
 762 extern bool same_translation_unit_p (const_tree, const_tree);
 763 extern int comptypes (tree, tree);
 764 extern bool comptypes_same_p (tree, tree);
 765 extern bool comptypes_equiv_p (tree, tree);
 766 extern int comptypes_check_different_types (tree, tree, bool *);
 767 extern int comptypes_check_enum_int (tree, tree, bool *);
 768 extern bool c_mark_addressable (tree, bool = false);
 769 extern void c_incomplete_type_error (location_t, const_tree, const_tree);
 770 extern tree c_type_promotes_to (tree);
 771 extern struct c_expr default_function_array_conversion (location_t,
 772                                                         struct c_expr);
 773 extern struct c_expr default_function_array_read_conversion (location_t,
 774                                                              struct c_expr);
 775 extern struct c_expr convert_lvalue_to_rvalue (location_t, struct c_expr,
 776                                                bool, bool, bool = false);
 777 extern tree decl_constant_value_1 (tree, bool);
 778 extern void mark_exp_read (tree);
 779 extern tree composite_type (tree, tree);
 780 extern tree lookup_field (const_tree, tree);
 781 extern tree build_component_ref (location_t, tree, tree, location_t,
 782                                  location_t, bool = true);
 783 extern tree build_array_ref (location_t, tree, tree);
 784 extern tree build_omp_array_section (location_t, tree, tree, tree);
 785 extern tree build_external_ref (location_t, tree, bool, tree *);
 786 extern void pop_maybe_used (bool);
 787 extern struct c_expr c_expr_sizeof_expr (location_t, struct c_expr);
 788 extern struct c_expr c_expr_sizeof_type (location_t, struct c_type_name *);
 789 extern struct c_expr parser_build_unary_op (location_t, enum tree_code,
 790                                             struct c_expr);
 791 extern struct c_expr parser_build_binary_op (location_t,
 792                                              enum tree_code, struct c_expr,
 793                                              struct c_expr);
 794 extern tree build_conditional_expr (location_t, tree, bool, tree, tree,
 795                                     location_t, tree, tree, location_t);
 796 extern tree build_compound_expr (location_t, tree, tree);
 797 extern tree c_cast_expr (location_t, struct c_type_name *, tree);
 798 extern tree build_c_cast (location_t, tree, tree);
 799 extern void store_init_value (location_t, tree, tree, tree);
 800 extern void maybe_warn_string_init (location_t, tree, struct c_expr);
 801 extern void start_init (tree, tree, bool, bool, rich_location *);
 802 extern void finish_init (void);
 803 extern void really_start_incremental_init (tree);
 804 extern void finish_implicit_inits (location_t, struct obstack *);
 805 extern void push_init_level (location_t, int, struct obstack *);
 806 extern struct c_expr pop_init_level (location_t, int, struct obstack *,
 807                                      location_t);
 808 extern void set_init_index (location_t, tree, tree, struct obstack *);
 809 extern void set_init_label (location_t, tree, location_t, struct obstack *);
 810 extern void process_init_element (location_t, struct c_expr, bool,
 811                                   struct obstack *);
 812 extern tree build_compound_literal (location_t, tree, tree, bool,
 813                                     unsigned int, struct c_declspecs *);
 814 extern void check_compound_literal_type (location_t, struct c_type_name *);
 815 extern tree c_start_switch (location_t, location_t, tree, bool);
 816 extern void c_finish_switch (tree, tree);
 817 extern tree build_asm_expr (location_t, tree, tree, tree, tree, tree, bool,
 818                             bool);
 819 extern tree build_asm_stmt (bool, tree);
 820 extern int c_types_compatible_p (tree, tree);
 821 extern tree c_begin_compound_stmt (bool);
 822 extern tree c_end_compound_stmt (location_t, tree, bool);
 823 extern void c_finish_if_stmt (location_t, tree, tree, tree);
 824 extern void c_finish_loop (location_t, location_t, tree, location_t, tree,
 825                            tree, tree, tree, bool);
 826 extern tree c_begin_stmt_expr (void);
 827 extern tree c_finish_stmt_expr (location_t, tree);
 828 extern tree c_process_expr_stmt (location_t, tree);
 829 extern tree c_finish_expr_stmt (location_t, tree);
 830 extern tree c_finish_return (location_t, tree, tree, bool = false);
 831 extern tree c_finish_bc_stmt (location_t, tree, bool);
 832 extern tree c_finish_goto_label (location_t, tree);
 833 extern tree c_finish_goto_ptr (location_t, c_expr val);
 834 extern tree c_expr_to_decl (tree, bool *, bool *);
 835 extern tree c_finish_omp_construct (location_t, enum tree_code, tree, tree);
 836 extern tree c_finish_oacc_data (location_t, tree, tree);
 837 extern tree c_finish_oacc_host_data (location_t, tree, tree);
 838 extern tree c_begin_omp_parallel (void);
 839 extern tree c_finish_omp_parallel (location_t, tree, tree);
 840 extern tree c_begin_omp_task (void);
 841 extern tree c_finish_omp_task (location_t, tree, tree);
 842 extern void c_finish_omp_cancel (location_t, tree);
 843 extern void c_finish_omp_cancellation_point (location_t, tree);
 844 extern tree c_finish_omp_clauses (tree, enum c_omp_region_type);
 845 extern tree c_build_va_arg (location_t, tree, location_t, tree);
 846 extern tree c_finish_transaction (location_t, tree, int);
 847 extern bool c_tree_equal (tree, tree);
 848 extern tree c_build_function_call_vec (location_t, const vec<location_t>&,
 849                                        tree, vec<tree, va_gc> *,
 850                                        vec<tree, va_gc> *);
 851 extern tree c_omp_clause_copy_ctor (tree, tree, tree);
 852
 853 /* Set to 0 at beginning of a function definition, set to 1 if
 854    a return statement that specifies a return value is seen.  */
 855
 856 extern int current_function_returns_value;
 857
 858 /* Set to 0 at beginning of a function definition, set to 1 if
 859    a return statement with no argument is seen.  */
 860
 861 extern int current_function_returns_null;
 862
 863 /* Set to 0 at beginning of a function definition, set to 1 if
 864    a call to a noreturn function is seen.  */
 865
 866 extern int current_function_returns_abnormally;
 867
 868 /* In c-decl.cc */
 869
 870 /* Tell the binding oracle what kind of binding we are looking for.  */
 871
 872 enum c_oracle_request
 873 {
 874   C_ORACLE_SYMBOL,
 875   C_ORACLE_TAG,
 876   C_ORACLE_LABEL
 877 };
 878
 879 /* If this is non-NULL, then it is a "binding oracle" which can lazily
 880    create bindings when needed by the C compiler.  The oracle is told
 881    the name and type of the binding to create.  It can call pushdecl
 882    or the like to ensure the binding is visible; or do nothing,
 883    leaving the binding untouched.  c-decl.cc takes note of when the
 884    oracle has been called and will not call it again if it fails to
 885    create a given binding.  */
 886
 887 typedef void c_binding_oracle_function (enum c_oracle_request, tree identifier);
 888
 889 extern c_binding_oracle_function *c_binding_oracle;
 890
 891 extern void c_finish_incomplete_decl (tree);
 892 extern tree c_omp_reduction_id (enum tree_code, tree);
 893 extern tree c_omp_reduction_decl (tree);
 894 extern tree c_omp_reduction_lookup (tree, tree);
 895 extern tree c_check_omp_declare_reduction_r (tree *, int *, void *);
 896 extern bool c_check_in_current_scope (tree);
 897 extern void c_pushtag (location_t, tree, tree);
 898 extern void c_bind (location_t, tree, bool);
 899 extern bool tag_exists_p (enum tree_code, tree);
 900
 901 /* In c-errors.cc */
 902 extern bool pedwarn_c90 (location_t, int opt, const char *, ...)
 903     ATTRIBUTE_GCC_DIAG(3,4);
 904 extern bool pedwarn_c99 (location_t, int opt, const char *, ...)
 905     ATTRIBUTE_GCC_DIAG(3,4);
 906 extern bool pedwarn_c11 (location_t, int opt, const char *, ...)
 907     ATTRIBUTE_GCC_DIAG(3,4);
 908 extern bool pedwarn_c23 (location_t, int opt, const char *, ...)
 909     ATTRIBUTE_GCC_DIAG(3,4);
 910
 911 extern void
 912 set_c_expr_source_range (c_expr *expr,
 913                          location_t start, location_t finish);
 914
 915 extern void
 916 set_c_expr_source_range (c_expr *expr,
 917                          source_range src_range);
 918
 919 /* In c-fold.cc */
 920 extern vec<tree> incomplete_record_decls;
 921
 922 extern const char *c_get_sarif_source_language (const char *filename);
 923
 924 extern const struct scoped_attribute_specs std_attribute_table;
 925
 926 #if CHECKING_P
 927 namespace selftest {
 928   extern void run_c_tests (void);
 929 } // namespace selftest
 930 #endif /* #if CHECKING_P */
 931
 932
 933 #endif /* ! GCC_C_TREE_H */