gcc/cp/cp-tree.def

   1 /* This file contains the definitions and documentation for the
   2    additional tree codes used in the GNU C++ compiler (see tree.def
   3    for the standard codes).
   4    Copyright (C) 1987-2016 Free Software Foundation, Inc.
   5    Hacked by Michael Tiemann (tiemann@cygnus.com)
   6
   7 This file is part of GCC.
   8
   9 GCC is free software; you can redistribute it and/or modify
  10 it under the terms of the GNU General Public License as published by
  11 the Free Software Foundation; either version 3, or (at your option)
  12 any later version.
  13
  14 GCC is distributed in the hope that it will be useful,
  15 but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 GNU General Public License for more details.
  18
  19 You should have received a copy of the GNU General Public License
  20 along with GCC; see the file COPYING3.  If not see
  21 <http://www.gnu.org/licenses/>.  */
  22
  23
  24 /* An OFFSET_REF is used in two situations:
  25
  26    1. An expression of the form `A::m' where `A' is a class and `m' is
  27       a non-static member.  In this case, operand 0 will be a TYPE
  28       (corresponding to `A') and operand 1 will be a FIELD_DECL,
  29       BASELINK, or TEMPLATE_ID_EXPR (corresponding to `m').
  30
  31       The expression is a pointer-to-member if its address is taken,
  32       but simply denotes a member of the object if its address is not
  33       taken.
  34
  35       This form is only used during the parsing phase; once semantic
  36       analysis has taken place they are eliminated.
  37
  38    2. An expression of the form `x.*p'.  In this case, operand 0 will
  39       be an expression corresponding to `x' and operand 1 will be an
  40       expression with pointer-to-member type.  */
  41 DEFTREECODE (OFFSET_REF, "offset_ref", tcc_reference, 2)
  42
  43 /* A pointer-to-member constant.  For a pointer-to-member constant
  44    `X::Y' The PTRMEM_CST_CLASS is the RECORD_TYPE for `X' and the
  45    PTRMEM_CST_MEMBER is the _DECL for `Y'.  */
  46 DEFTREECODE (PTRMEM_CST, "ptrmem_cst", tcc_constant, 0)
  47
  48 /* For NEW_EXPR, operand 0 is the placement list.
  49    Operand 1 is the new-declarator.
  50    Operand 2 is the number of elements in the array.
  51    Operand 3 is the initializer.  */
  52 DEFTREECODE (NEW_EXPR, "nw_expr", tcc_expression, 4)
  53 DEFTREECODE (VEC_NEW_EXPR, "vec_nw_expr", tcc_expression, 3)
  54
  55 /* For DELETE_EXPR, operand 0 is the store to be destroyed.
  56    Operand 1 is the value to pass to the destroying function
  57    saying whether the store should be deallocated as well.  */
  58 DEFTREECODE (DELETE_EXPR, "dl_expr", tcc_expression, 2)
  59 DEFTREECODE (VEC_DELETE_EXPR, "vec_dl_expr", tcc_expression, 2)
  60
  61 /* Value is reference to particular overloaded class method.
  62    Operand 0 is the class, operand 1 is the field
  63    The COMPLEXITY field holds the class level (usually 0).  */
  64 DEFTREECODE (SCOPE_REF, "scope_ref", tcc_reference, 2)
  65
  66 /* When composing an object with a member, this is the result.
  67    Operand 0 is the object.  Operand 1 is the member (usually
  68    a dereferenced pointer to member).  */
  69 DEFTREECODE (MEMBER_REF, "member_ref", tcc_reference, 2)
  70
  71 /* Type conversion operator in C++.  TREE_TYPE is type that this
  72    operator converts to.  Operand is expression to be converted.  */
  73 DEFTREECODE (TYPE_EXPR, "type_expr", tcc_expression, 1)
  74
  75 /* AGGR_INIT_EXPRs have a variably-sized representation similar to
  76    that of CALL_EXPRs.  Operand 0 is an INTEGER_CST node containing the
  77    operand count, operand 1 is the function which performs initialization,
  78    operand 2 is the slot which was allocated for this expression, and
  79    the remaining operands are the arguments to the initialization function.  */
  80 DEFTREECODE (AGGR_INIT_EXPR, "aggr_init_expr", tcc_vl_exp, 3)
  81
  82 /* Initialization of an array from another array, expressed at a high level
  83    so that it works with TARGET_EXPR.  Operand 0 is the target, operand 1
  84    is the initializer.  */
  85 DEFTREECODE (VEC_INIT_EXPR, "vec_init_expr", tcc_expression, 2)
  86
  87 /* A throw expression.  operand 0 is the expression, if there was one,
  88    else it is NULL_TREE.  */
  89 DEFTREECODE (THROW_EXPR, "throw_expr", tcc_expression, 1)
  90
  91 /* An empty class object.  The TREE_TYPE gives the class type.  We use
  92    these to avoid actually creating instances of the empty classes.  */
  93 DEFTREECODE (EMPTY_CLASS_EXPR, "empty_class_expr", tcc_expression, 0)
  94
  95 /* A reference to a member function or member functions from a base
  96    class.  BASELINK_FUNCTIONS gives the FUNCTION_DECL,
  97    TEMPLATE_DECL, OVERLOAD, or TEMPLATE_ID_EXPR corresponding to the
  98    functions.  BASELINK_BINFO gives the base from which the functions
  99    come, i.e., the base to which the `this' pointer must be converted
 100    before the functions are called.  BASELINK_ACCESS_BINFO gives the
 101    base used to name the functions.
 102
 103    A BASELINK is an expression; the TREE_TYPE of the BASELINK gives
 104    the type of the expression.  This type is either a FUNCTION_TYPE,
 105    METHOD_TYPE, or `unknown_type_node' indicating that the function is
 106    overloaded.  */
 107 DEFTREECODE (BASELINK, "baselink", tcc_exceptional, 0)
 108
 109 /* Template definition.  The following fields have the specified uses,
 110    although there are other macros in cp-tree.h that should be used for
 111    accessing this data.
 112         DECL_ARGUMENTS          template parm vector
 113         DECL_TEMPLATE_INFO      template text &c
 114         DECL_VINDEX             list of instantiations already produced;
 115                                 only done for functions so far
 116    For class template:
 117         DECL_INITIAL            associated templates (methods &c)
 118         DECL_TEMPLATE_RESULT    null
 119    For non-class templates:
 120         TREE_TYPE               type of object to be constructed
 121         DECL_TEMPLATE_RESULT    decl for object to be created
 122                                 (e.g., FUNCTION_DECL with tmpl parms used)
 123  */
 124 DEFTREECODE (TEMPLATE_DECL, "template_decl", tcc_declaration, 0)
 125
 126 /* Index into a template parameter list.  The TEMPLATE_PARM_IDX gives
 127    the index (from 0) of the parameter, while the TEMPLATE_PARM_LEVEL
 128    gives the level (from 1) of the parameter.
 129
 130    Here's an example:
 131
 132    template <class T> // Index 0, Level 1.
 133    struct S
 134    {
 135       template <class U, // Index 0, Level 2.
 136                 class V> // Index 1, Level 2.
 137       void f();
 138    };
 139
 140    The DESCENDANTS will be a chain of TEMPLATE_PARM_INDEXs descended
 141    from this one.  The first descendant will have the same IDX, but
 142    its LEVEL will be one less.  The TREE_CHAIN field is used to chain
 143    together the descendants.  The TEMPLATE_PARM_DECL is the
 144    declaration of this parameter, either a TYPE_DECL or CONST_DECL.
 145    The TEMPLATE_PARM_ORIG_LEVEL is the LEVEL of the most distant
 146    parent, i.e., the LEVEL that the parameter originally had when it
 147    was declared.  For example, if we instantiate S<int>, we will have:
 148
 149    struct S<int>
 150    {
 151      template <class U, // Index 0, Level 1, Orig Level 2
 152                class V> // Index 1, Level 1, Orig Level 2
 153      void f();
 154    };
 155
 156    The LEVEL is the level of the parameter when we are worrying about
 157    the types of things; the ORIG_LEVEL is the level when we are
 158    worrying about instantiating things.  */
 159 DEFTREECODE (TEMPLATE_PARM_INDEX, "template_parm_index", tcc_exceptional, 0)
 160
 161 /* Index into a template parameter list for template template parameters.
 162    This parameter must be a type.  The TYPE_FIELDS value will be a
 163    TEMPLATE_PARM_INDEX.
 164
 165    It is used without template arguments like TT in C<TT>,
 166    TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO is NULL_TREE
 167    and TYPE_NAME is a TEMPLATE_DECL.  */
 168 DEFTREECODE (TEMPLATE_TEMPLATE_PARM, "template_template_parm", tcc_type, 0)
 169
 170 /* The ordering of the following codes is optimized for the checking
 171    macros in tree.h.  Changing the order will degrade the speed of the
 172    compiler.  TEMPLATE_TYPE_PARM, TYPENAME_TYPE, TYPEOF_TYPE,
 173    BOUND_TEMPLATE_TEMPLATE_PARM.  */
 174
 175 /* Index into a template parameter list.  This parameter must be a type.
 176    The type.values field will be a TEMPLATE_PARM_INDEX.  */
 177 DEFTREECODE (TEMPLATE_TYPE_PARM, "template_type_parm", tcc_type, 0)
 178
 179 /* A type designated by `typename T::t'.  TYPE_CONTEXT is `T',
 180    TYPE_NAME is an IDENTIFIER_NODE for `t'.  If the type was named via
 181    template-id, TYPENAME_TYPE_FULLNAME will hold the TEMPLATE_ID_EXPR.
 182    TREE_TYPE is always NULL.  */
 183 DEFTREECODE (TYPENAME_TYPE, "typename_type", tcc_type, 0)
 184
 185 /* A type designated by `__typeof (expr)'.  TYPEOF_TYPE_EXPR is the
 186    expression in question.  */
 187 DEFTREECODE (TYPEOF_TYPE, "typeof_type", tcc_type, 0)
 188
 189 /* Like TEMPLATE_TEMPLATE_PARM it is used with bound template arguments
 190    like TT<int>.
 191    In this case, TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO contains the
 192    template name and its bound arguments.  TYPE_NAME is a TYPE_DECL.  */
 193 DEFTREECODE (BOUND_TEMPLATE_TEMPLATE_PARM, "bound_template_template_parm",
 194              tcc_type, 0)
 195
 196 /* For template template argument of the form `T::template C'.
 197    TYPE_CONTEXT is `T', the template parameter dependent object.
 198    TYPE_NAME is an IDENTIFIER_NODE for `C', the member class template.  */
 199 DEFTREECODE (UNBOUND_CLASS_TEMPLATE, "unbound_class_template", tcc_type, 0)
 200
 201 /* A using declaration.  USING_DECL_SCOPE contains the specified
 202    scope.  In a member using decl, unless DECL_DEPENDENT_P is true,
 203    USING_DECL_DECLS contains the _DECL or OVERLOAD so named.  This is
 204    not an alias, but is later expanded into multiple aliases.  */
 205 DEFTREECODE (USING_DECL, "using_decl", tcc_declaration, 0)
 206
 207 /* A using directive. The operand is USING_STMT_NAMESPACE.  */
 208 DEFTREECODE (USING_STMT, "using_stmt", tcc_statement, 1)
 209
 210 /* An un-parsed default argument.  Holds a vector of input tokens and
 211    a vector of places where the argument was instantiated before
 212    parsing had occurred.  */
 213 DEFTREECODE (DEFAULT_ARG, "default_arg", tcc_exceptional, 0)
 214
 215 /* An uninstantiated/unevaluated noexcept-specification.  For the
 216    uninstantiated case, DEFERRED_NOEXCEPT_PATTERN is the pattern from the
 217    template, and DEFERRED_NOEXCEPT_ARGS are the template arguments to
 218    substitute into the pattern when needed.  For the unevaluated case,
 219    those slots are NULL_TREE and we use get_defaulted_eh_spec to find
 220    the exception-specification.  */
 221 DEFTREECODE (DEFERRED_NOEXCEPT, "deferred_noexcept", tcc_exceptional, 0)
 222
 223 /* A template-id, like foo<int>.  The first operand is the template.
 224    The second is NULL if there are no explicit arguments, or a
 225    TREE_VEC of arguments.  The template will be a FUNCTION_DECL,
 226    TEMPLATE_DECL, or an OVERLOAD.  If the template-id refers to a
 227    member template, the template may be an IDENTIFIER_NODE.  */
 228 DEFTREECODE (TEMPLATE_ID_EXPR, "template_id_expr", tcc_expression, 2)
 229
 230 /* A list-like node for chaining overloading candidates. TREE_TYPE is
 231    the original name, and the parameter is the FUNCTION_DECL.  */
 232 DEFTREECODE (OVERLOAD, "overload", tcc_exceptional, 0)
 233
 234 /* A pseudo-destructor, of the form "OBJECT.~DESTRUCTOR" or
 235    "OBJECT.SCOPE::~DESTRUCTOR.  The first operand is the OBJECT.  The
 236    second operand (if non-NULL) is the SCOPE.  The third operand is
 237    the TYPE node corresponding to the DESTRUCTOR.  The type of the
 238    first operand will always be a scalar type.
 239
 240    The type of a PSEUDO_DTOR_EXPR is always "void", even though it can
 241    be used as if it were a zero-argument function.  We handle the
 242    function-call case specially, and giving it "void" type prevents it
 243    being used in expressions in ways that are not permitted.  */
 244 DEFTREECODE (PSEUDO_DTOR_EXPR, "pseudo_dtor_expr", tcc_expression, 3)
 245
 246 /* A whole bunch of tree codes for the initial, superficial parsing of
 247    templates.  */
 248 DEFTREECODE (MODOP_EXPR, "modop_expr", tcc_expression, 3)
 249 DEFTREECODE (CAST_EXPR, "cast_expr", tcc_unary, 1)
 250 DEFTREECODE (REINTERPRET_CAST_EXPR, "reinterpret_cast_expr", tcc_unary, 1)
 251 DEFTREECODE (CONST_CAST_EXPR, "const_cast_expr", tcc_unary, 1)
 252 DEFTREECODE (STATIC_CAST_EXPR, "static_cast_expr", tcc_unary, 1)
 253 DEFTREECODE (DYNAMIC_CAST_EXPR, "dynamic_cast_expr", tcc_unary, 1)
 254 DEFTREECODE (IMPLICIT_CONV_EXPR, "implicit_conv_expr", tcc_unary, 1)
 255 DEFTREECODE (DOTSTAR_EXPR, "dotstar_expr", tcc_expression, 2)
 256 DEFTREECODE (TYPEID_EXPR, "typeid_expr", tcc_expression, 1)
 257 DEFTREECODE (NOEXCEPT_EXPR, "noexcept_expr", tcc_unary, 1)
 258
 259 /* A placeholder for an expression that is not type-dependent, but
 260    does occur in a template.  When an expression that is not
 261    type-dependent appears in a larger expression, we must compute the
 262    type of that larger expression.  That computation would normally
 263    modify the original expression, which would change the mangling of
 264    that expression if it appeared in a template argument list.  In
 265    that situation, we create a NON_DEPENDENT_EXPR to take the place of
 266    the original expression.  The expression is the only operand -- it
 267    is only needed for diagnostics.  */
 268 DEFTREECODE (NON_DEPENDENT_EXPR, "non_dependent_expr", tcc_expression, 1)
 269
 270 /* CTOR_INITIALIZER is a placeholder in template code for a call to
 271    setup_vtbl_pointer (and appears in all functions, not just ctors).  */
 272 DEFTREECODE (CTOR_INITIALIZER, "ctor_initializer", tcc_expression, 1)
 273
 274 DEFTREECODE (TRY_BLOCK, "try_block", tcc_statement, 2)
 275
 276 DEFTREECODE (EH_SPEC_BLOCK, "eh_spec_block", tcc_statement, 2)
 277
 278 /* A HANDLER wraps a catch handler for the HANDLER_TYPE.  If this is
 279    CATCH_ALL_TYPE, then the handler catches all types.  The declaration of
 280    the catch variable is in HANDLER_PARMS, and the body block in
 281    HANDLER_BODY.  */
 282 DEFTREECODE (HANDLER, "handler", tcc_statement, 2)
 283
 284 /* A MUST_NOT_THROW_EXPR wraps an expression that may not
 285    throw, and must call terminate if it does.  The second argument
 286    is a condition, used in templates to express noexcept (condition).  */
 287 DEFTREECODE (MUST_NOT_THROW_EXPR, "must_not_throw_expr", tcc_expression, 2)
 288
 289 /* A CLEANUP_STMT marks the point at which a declaration is fully
 290    constructed.  The CLEANUP_EXPR is run on behalf of CLEANUP_DECL
 291    when CLEANUP_BODY completes.  */
 292 DEFTREECODE (CLEANUP_STMT, "cleanup_stmt", tcc_statement, 3)
 293
 294 /* Represents an 'if' statement. The operands are IF_COND,
 295    THEN_CLAUSE, and ELSE_CLAUSE, and the current scope, respectively.  */
 296 /* ??? It is currently still necessary to distinguish between IF_STMT
 297    and COND_EXPR for the benefit of templates.  */
 298 DEFTREECODE (IF_STMT, "if_stmt", tcc_statement, 4)
 299
 300 /* Used to represent a `for' statement. The operands are
 301    FOR_INIT_STMT, FOR_COND, FOR_EXPR, and FOR_BODY, respectively.  */
 302 DEFTREECODE (FOR_STMT, "for_stmt", tcc_statement, 5)
 303
 304 /* Used to represent a range-based `for' statement. The operands are
 305    RANGE_FOR_DECL, RANGE_FOR_EXPR, RANGE_FOR_BODY, and RANGE_FOR_SCOPE,
 306    respectively.  Only used in templates.  */
 307 DEFTREECODE (RANGE_FOR_STMT, "range_for_stmt", tcc_statement, 4)
 308
 309 /* Used to represent a 'while' statement. The operands are WHILE_COND
 310    and WHILE_BODY, respectively.  */
 311 DEFTREECODE (WHILE_STMT, "while_stmt", tcc_statement, 2)
 312
 313 /* Used to represent a 'do' statement. The operands are DO_BODY and
 314    DO_COND, respectively.  */
 315 DEFTREECODE (DO_STMT, "do_stmt", tcc_statement, 2)
 316
 317 /* Used to represent a 'break' statement.  */
 318 DEFTREECODE (BREAK_STMT, "break_stmt", tcc_statement, 0)
 319
 320 /* Used to represent a 'continue' statement.  */
 321 DEFTREECODE (CONTINUE_STMT, "continue_stmt", tcc_statement, 0)
 322
 323 /* Used to represent a 'switch' statement. The operands are
 324    SWITCH_STMT_COND, SWITCH_STMT_BODY, SWITCH_STMT_TYPE, and
 325    SWITCH_STMT_SCOPE, respectively.  */
 326 DEFTREECODE (SWITCH_STMT, "switch_stmt", tcc_statement, 4)
 327
 328 /* Used to represent an expression statement.  Use `EXPR_STMT_EXPR' to
 329    obtain the expression.  */
 330 DEFTREECODE (EXPR_STMT, "expr_stmt", tcc_expression, 1)
 331
 332 DEFTREECODE (TAG_DEFN, "tag_defn", tcc_expression, 0)
 333
 334 /* Represents an 'offsetof' expression during template expansion.  */
 335 DEFTREECODE (OFFSETOF_EXPR, "offsetof_expr", tcc_expression, 1)
 336
 337 /* Represents the -> operator during template expansion.  */
 338 DEFTREECODE (ARROW_EXPR, "arrow_expr", tcc_expression, 1)
 339
 340 /* Represents an '__alignof__' expression during template
 341    expansion.  */
 342 DEFTREECODE (ALIGNOF_EXPR, "alignof_expr", tcc_expression, 1)
 343
 344 /* Represents an Objective-C++ '@encode' expression during template
 345    expansion.  */
 346 DEFTREECODE (AT_ENCODE_EXPR, "at_encode_expr", tcc_expression, 1)
 347
 348 /* A STMT_EXPR represents a statement-expression during template
 349    expansion.  This is the GCC extension { ( ... ) }.  The
 350    STMT_EXPR_STMT is the statement given by the expression.  */
 351 DEFTREECODE (STMT_EXPR, "stmt_expr", tcc_expression, 1)
 352
 353 /* Unary plus. Operand 0 is the expression to which the unary plus
 354    is applied.  */
 355 DEFTREECODE (UNARY_PLUS_EXPR, "unary_plus_expr", tcc_unary, 1)
 356
 357 /** C++11 extensions. */
 358
 359 /* A static assertion.  This is a C++11 extension.
 360    STATIC_ASSERT_CONDITION contains the condition that is being
 361    checked.  STATIC_ASSERT_MESSAGE contains the message (a string
 362    literal) to be displayed if the condition fails to hold.  */
 363 DEFTREECODE (STATIC_ASSERT, "static_assert", tcc_exceptional, 0)
 364
 365 /* Represents an argument pack of types (or templates). An argument
 366    pack stores zero or more arguments that will be used to instantiate
 367    a parameter pack.
 368
 369    ARGUMENT_PACK_ARGS retrieves the arguments stored in the argument
 370    pack.
 371
 372    Example:
 373      template<typename... Values>
 374      class tuple { ... };
 375
 376      tuple<int, float, double> t;
 377
 378    Values is a (template) parameter pack. When tuple<int, float,
 379    double> is instantiated, the Values parameter pack is instantiated
 380    with the argument pack <int, float, double>. ARGUMENT_PACK_ARGS will
 381    be a TREE_VEC containing int, float, and double.  */
 382 DEFTREECODE (TYPE_ARGUMENT_PACK, "type_argument_pack", tcc_type, 0)
 383
 384 /* Represents an argument pack of values, which can be used either for
 385    non-type template arguments or function call arguments.
 386
 387    NONTYPE_ARGUMENT_PACK plays precisely the same role as
 388    TYPE_ARGUMENT_PACK, but will be used for packing non-type template
 389    arguments (e.g., "int... Dimensions") or function arguments ("const
 390    Args&... args"). */
 391 DEFTREECODE (NONTYPE_ARGUMENT_PACK, "nontype_argument_pack", tcc_expression, 1)
 392
 393 /* Represents a type expression that will be expanded into a list of
 394    types when instantiated with one or more argument packs.
 395
 396    PACK_EXPANSION_PATTERN retrieves the expansion pattern. This is
 397    the type or expression that we will substitute into with each
 398    argument in an argument pack.
 399
 400    SET_PACK_EXPANSION_PATTERN sets the expansion pattern.
 401
 402    PACK_EXPANSION_PARAMETER_PACKS contains a TREE_LIST of the parameter
 403    packs that are used in this pack expansion.
 404
 405    Example:
 406      template<typename... Values>
 407      struct tied : tuple<Values&...> {
 408        // ...
 409      };
 410
 411    The derivation from tuple contains a TYPE_PACK_EXPANSION for the
 412    template arguments. Its PACK_EXPANSION_PATTERN is "Values&" and its
 413    PACK_EXPANSION_PARAMETER_PACKS will contain "Values".  */
 414 DEFTREECODE (TYPE_PACK_EXPANSION, "type_pack_expansion", tcc_type, 0)
 415
 416 /* Represents an expression that will be expanded into a list of
 417    expressions when instantiated with one or more argument packs.
 418
 419    EXPR_PACK_EXPANSION plays precisely the same role as TYPE_PACK_EXPANSION,
 420    but will be used for expressions.  */
 421 DEFTREECODE (EXPR_PACK_EXPANSION, "expr_pack_expansion", tcc_expression, 3)
 422
 423 /* Selects the Ith parameter out of an argument pack. This node will
 424    be used when instantiating pack expansions; see
 425    tsubst_pack_expansion.
 426
 427    ARGUMENT_PACK_SELECT_FROM_PACK contains the *_ARGUMENT_PACK node
 428    from which the argument will be selected.
 429
 430    ARGUMENT_PACK_SELECT_INDEX contains the index into the argument
 431    pack that will be returned by this ARGUMENT_PACK_SELECT node. The
 432    index is a machine integer.  */
 433 DEFTREECODE (ARGUMENT_PACK_SELECT, "argument_pack_select", tcc_exceptional, 0)
 434
 435 /* Fold expressions allow the expansion of a template argument pack
 436    over a binary operator.
 437
 438    FOLD_EXPR_MOD_P is true when the fold operation is a compound assignment
 439    operator.
 440
 441    FOLD_EXPR_OP is an INTEGER_CST storing the tree code for the folded
 442    expression. Note that when FOLDEXPR_MOD_P is true, the operator is
 443    a compound assignment operator for that kind of expression.
 444
 445    FOLD_EXPR_PACK is an expression containing an unexpanded parameter pack;
 446    when expanded, each term becomes an argument of the folded expression.
 447
 448    In a BINARY_FOLD_EXPRESSION, FOLD_EXPR_INIT is the non-pack argument. */
 449 DEFTREECODE (UNARY_LEFT_FOLD_EXPR, "unary_left_fold_expr", tcc_expression, 2)
 450 DEFTREECODE (UNARY_RIGHT_FOLD_EXPR, "unary_right_fold_expr", tcc_expression, 2)
 451 DEFTREECODE (BINARY_LEFT_FOLD_EXPR, "binary_left_fold_expr", tcc_expression, 3)
 452 DEFTREECODE (BINARY_RIGHT_FOLD_EXPR, "binary_right_fold_expr", tcc_expression, 3)
 453
 454
 455 /** C++ extensions. */
 456
 457 /* Represents a trait expression during template expansion.  */
 458 DEFTREECODE (TRAIT_EXPR, "trait_expr", tcc_exceptional, 0)
 459
 460 /* A lambda expression.  This is a C++0x extension.
 461    LAMBDA_EXPR_DEFAULT_CAPTURE_MODE is an enum for the default, which may be
 462    none.
 463    LAMBDA_EXPR_CAPTURE_LIST holds the capture-list, including `this'.
 464    LAMBDA_EXPR_THIS_CAPTURE goes straight to the capture of `this', if it exists.
 465    LAMBDA_EXPR_PENDING_PROXIES is a vector of capture proxies which need to
 466    be pushed once scope returns to the lambda.
 467    LAMBDA_EXPR_MUTABLE_P signals whether this lambda was declared mutable.
 468    LAMBDA_EXPR_RETURN_TYPE holds the return type, if it was specified.  */
 469 DEFTREECODE (LAMBDA_EXPR, "lambda_expr", tcc_exceptional, 0)
 470
 471 /* The declared type of an expression.  This is a C++0x extension.
 472    DECLTYPE_TYPE_EXPR is the expression whose type we are computing.
 473    DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P states whether the
 474    expression was parsed as an id-expression or a member access
 475    expression. When false, it was parsed as a full expression.
 476    DECLTYPE_FOR_LAMBDA_CAPTURE is set if we want lambda capture semantics.
 477    DECLTYPE_FOR_LAMBDA_RETURN is set if we want lambda return deduction.  */
 478 DEFTREECODE (DECLTYPE_TYPE, "decltype_type", tcc_type, 0)
 479
 480 /* A type designated by `__underlying_type (type)'.
 481    UNDERLYING_TYPE_TYPE is the type in question.  */
 482 DEFTREECODE (UNDERLYING_TYPE, "underlying_type", tcc_type, 0)
 483
 484 /* A type designated by one of the bases type traits.
 485    BASES_TYPE is the type in question.  */
 486 DEFTREECODE (BASES, "bases", tcc_type, 0)
 487
 488 /* Used to represent the template information stored by template
 489    specializations.
 490    The accessors are:
 491    TI_TEMPLATE the template declaration associated to the specialization
 492    TI_ARGS the arguments of the template specialization
 493    TI_TYPEDEFS_NEEDING_ACCESS_CHECKING the vector of typedefs used in
 494    the pattern of the template for which access check is needed at template
 495    instantiation time.  */
 496 DEFTREECODE (TEMPLATE_INFO, "template_info", tcc_exceptional, 0)
 497
 498 /* Extensions for Concepts. */
 499
 500 /* Used to represent information associated with constrained declarations. */
 501 DEFTREECODE (CONSTRAINT_INFO, "constraint_info", tcc_exceptional, 0)
 502
 503 /* A wildcard declaration is a placeholder for a template parameter
 504    used to resolve constrained-type-names in concepts.  During
 505    resolution, the matching argument is saved as the TREE_TYPE
 506    of the wildcard.  */
 507 DEFTREECODE (WILDCARD_DECL, "wildcard_decl", tcc_declaration, 0)
 508
 509 /* A requires-expr is a binary expression. The first operand is
 510    its parameter list (possibly NULL). The second is a list of
 511    requirements, which are denoted by the _REQ* tree codes
 512    below. */
 513 DEFTREECODE (REQUIRES_EXPR,   "requires_expr", tcc_expression, 2)
 514
 515 /* A requirement for an expression. */
 516 DEFTREECODE (SIMPLE_REQ, "simple_req", tcc_expression, 1)
 517
 518 /* A requirement for a type. */
 519 DEFTREECODE (TYPE_REQ, "type_req", tcc_expression, 1)
 520
 521 /* A requirement for an expression and its properties. The
 522    first operand is the expression, and the 2nd is its type.
 523    The accessor COMPOUND_REQ_NOEXCEPT determines whether
 524    the noexcept keyword was present. */
 525 DEFTREECODE (COMPOUND_REQ, "compound_req", tcc_expression, 2)
 526
 527 /* A requires clause within a requires expression. */
 528 DEFTREECODE (NESTED_REQ, "nested_req", tcc_expression, 1)
 529
 530 /* Constraints are modeled as kinds of expressions.
 531    The operands of a constraint can be either types or expressions.
 532    Unlike expressions, constraints do not have a type. */
 533
 534 /* A predicate constraint evaluates an expression E.
 535
 536    PRED_CONSTR_EXPR has the expression to be evaluated. */
 537 DEFTREECODE (PRED_CONSTR, "pred_constr", tcc_expression, 1)
 538
 539 /* An expression constraint determines the validity of a expression E.
 540
 541    EXPR_CONST_EXPR has the expression being validated. */
 542 DEFTREECODE (EXPR_CONSTR, "expr_constr", tcc_expression, 1)
 543
 544 /* A type constraint determines the validity of a type T. Note that
 545
 546    TYPE_CONST_TYPE has the type being validated */
 547 DEFTREECODE (TYPE_CONSTR, "type_constr", tcc_expression, 1)
 548
 549 /* An implicit conversion constraint determines if an expression
 550    E is implicitly convertible to a type T. Note that T may
 551    be dependent but does not contain any placeholders.
 552
 553    ICONV_CONSTR_EXPR has the expression E.
 554    ICONV_CONSTR_TYPE has the type T.
 555    */
 556 DEFTREECODE (ICONV_CONSTR, "iconv_constr", tcc_expression, 2)
 557
 558 /* An argument deduction constraint determines if the type of an
 559    expression E can be deduced from a type pattern T. Note that
 560    T must contain at least one place holder.
 561
 562    DEDUCT_CONSTR_EXPR has the expression E
 563    DEDUCT_CONSTR_PATTERN has the type patter T.
 564    DEDUCT_CONSTR_PLACEHOLDERS has the list of placeholder nodes in T. */
 565 DEFTREECODE (DEDUCT_CONSTR, "deduct_constr", tcc_expression, 3)
 566
 567 /* An exception constraint determines if, for an expression E,
 568    noexcept(E) is true.
 569
 570    EXCEPT_CONSTR_EXPR has the expression E. */
 571 DEFTREECODE (EXCEPT_CONSTR, "except_constr", tcc_expression, 1)
 572
 573 /* A parameterized constraint declares constraint variables, which
 574    are used in expression, type, and exception constraints.
 575
 576    PARM_CONSTR_PARMS has a TREE_LIST of parameter declarations.
 577    PARM_CONSTR_OPERAND has the nested constraint. */
 578 DEFTREECODE (PARM_CONSTR, "parm_constr", tcc_expression, 2)
 579
 580 /* The conjunction and disjunction of two constraints, respectively.
 581    Operands are accessed using TREE_OPERAND. */
 582 DEFTREECODE (CONJ_CONSTR, "conj_constr", tcc_expression, 2)
 583 DEFTREECODE (DISJ_CONSTR, "disj_constr", tcc_expression, 2)
 584
 585
 586 /*
 587 Local variables:
 588 mode:c
 589 End:
 590 */