eing used somewhere, which
   is not important for this node.  */
#define OVL_USED(NODE)		TREE_USED (OVERLOAD_CHECK (NODE))
/* If set, this OVERLOAD was created for argument-dependent lookup
   and can be freed afterward.  */
#define OVL_ARG_DEPENDENT(NODE) TREE_LANG_FLAG_0 (OVERLOAD_CHECK (NODE))

struct GTY(()) tree_overload {
  struct tree_common common;
  tree function;
};

struct GTY(()) tree_template_decl {
  struct tree_decl_common common;
  tree arguments;
  tree result;
};

/* Returns true iff NODE is a BASELINK.  */
#define BASELINK_P(NODE) \
  (TREE_CODE (NODE) == BASELINK)
/* The BINFO indicating the base in which lookup found the
   BASELINK_FUNCTIONS.  */
#define BASELINK_BINFO(NODE) \
  (((struct tree_baselink*) BASELINK_CHECK (NODE))->binfo)
/* The functions referred to by the BASELINK; either a FUNCTION_DECL,
   a TEMPLATE_DECL, an OVERLOAD, or a TEMPLATE_ID_EXPR.  */
#define BASELINK_FUNCTIONS(NODE) \
  (((struct tree_baselink*) BASELINK_CHECK (NODE))->functions)
/* The BINFO in which the search for the functions indicated by this baselink
   began.  This base is used to determine the accessibility of functions
   selected by overload resolution.  */
#define BASELINK_ACCESS_BINFO(NODE) \
  (((struct tree_baselink*) BASELINK_CHECK (NODE))->access_binfo)
/* For a type-conversion operator, the BASELINK_OPTYPE indicates the type
   to which the conversion should occur.  This value is important if
   the BASELINK_FUNCTIONS include a template conversion operator --
   the BASELINK_OPTYPE can be used to determine what type the user
   requested.  */
#define BASELINK_OPTYPE(NODE) \
  (TREE_CHAIN (BASELINK_CHECK (NODE)))
/* Nonzero if this baselink was from a qualified lookup.  */
#define BASELINK_QUALIFIED_P(NODE) \
  TREE_LANG_FLAG_0 (BASELINK_CHECK (NODE))

struct GTY(()) tree_baselink {
  struct tree_common common;
  tree binfo;
  tree functions;
  tree access_binfo;
};

/* The different kinds of ids that we encounter.  */

enum cp_id_kind
{
  /* Not an id at all.  */
  CP_ID_KIND_NONE,
  /* An unqualified-id that is not a template-id.  */
  CP_ID_KIND_UNQUALIFIED,
  /* An unqualified-id that is a dependent name.  */
  CP_ID_KIND_UNQUALIFIED_DEPENDENT,
  /* An unqualified template-id.  */
  CP_ID_KIND_TEMPLATE_ID,
  /* A qualified-id.  */
  CP_ID_KIND_QUALIFIED
};


/* The various kinds of C++0x warnings we encounter. */

enum cpp0x_warn_str
{
  /* extended initializer lists */
  CPP0X_INITIALIZER_LISTS,
  /* explicit conversion operators */
  CPP0X_EXPLICIT_CONVERSION,
  /* variadic templates */
  CPP0X_VARIADIC_TEMPLATES,
  /* lambda expressions */
  CPP0X_LAMBDA_EXPR,
  /* C++0x auto */
  CPP0X_AUTO,
  /* scoped enums */
  CPP0X_SCOPED_ENUMS,
  /* defaulted and deleted functions */
  CPP0X_DEFAULTED_DELETED,
  /* inline namespaces */
  CPP0X_INLINE_NAMESPACES,
  /* override controls, override/final */
  CPP0X_OVERRIDE_CONTROLS,
  /* non-static data member initializers */
  CPP0X_NSDMI,
  /* user defined literals */
  CPP0X_USER_DEFINED_LITERALS,
  /* delegating constructors */
  CPP0X_DELEGATING_CTORS,
  /* inheriting constructors */
  CPP0X_INHERITING_CTORS,
  /* C++11 attributes */
  CPP0X_ATTRIBUTES,
  /* ref-qualified member functions */
  CPP0X_REF_QUALIFIER
};

/* The various kinds of operation used by composite_pointer_type. */

enum composite_pointer_operation
{
  /* comparison */
  CPO_COMPARISON,
  /* conversion */
  CPO_CONVERSION,
  /* conditional expression */
  CPO_CONDITIONAL_EXPR
};

/* Possible cases of expression list used by build_x_compound_expr_from_list. */
enum expr_list_kind {
  ELK_INIT,		/* initializer */
  ELK_MEM_INIT,		/* member initializer */
  ELK_FUNC_CAST		/* functional cast */
};

/* Possible cases of implicit bad rhs conversions. */
enum impl_conv_rhs {
  ICR_DEFAULT_ARGUMENT, /* default argument */
  ICR_CONVERTING,       /* converting */
  ICR_INIT,             /* initialization */
  ICR_ARGPASS,          /* argument passing */
  ICR_RETURN,           /* return */
  ICR_ASSIGN            /* assignment */
};

/* Possible cases of implicit or explicit bad conversions to void. */
enum impl_conv_void {
  ICV_CAST,            /* (explicit) conversion to void */
  ICV_SECOND_OF_COND,  /* second operand of conditional expression */
  ICV_THIRD_OF_COND,   /* third operand of conditional expression */
  ICV_RIGHT_OF_COMMA,  /* right operand of comma operator */
  ICV_LEFT_OF_COMMA,   /* left operand of comma operator */
  ICV_STATEMENT,       /* statement */
  ICV_THIRD_IN_FOR     /* for increment expression */
};

/* Possible invalid uses of an abstract class that might not have a
   specific associated declaration.  */
enum GTY(()) abstract_class_use {
  ACU_UNKNOWN,			/* unknown or decl provided */
  ACU_CAST,			/* cast to abstract class */
  ACU_NEW,			/* new-expression of abstract class */
  ACU_THROW,			/* throw-expression of abstract class */
  ACU_CATCH,			/* catch-parameter of abstract class */
  ACU_ARRAY,			/* array of abstract class */
  ACU_RETURN,			/* return type of abstract class */
  ACU_PARM			/* parameter type of abstract class */
};

/* Macros for access to language-specific slots in an identifier.  */

#define IDENTIFIER_NAMESPACE_BINDINGS(NODE)	\
  (LANG_IDENTIFIER_CAST (NODE)->namespace_bindings)
#define IDENTIFIER_TEMPLATE(NODE)	\
  (LANG_IDENTIFIER_CAST (NODE)->class_template_info)

/* The IDENTIFIER_BINDING is the innermost cxx_binding for the
    identifier.  It's PREVIOUS is the next outermost binding.  Each
    VALUE field is a DECL for the associated declaration.  Thus,
    name lookup consists simply of pulling off the node at the front
    of the list (modulo oddities for looking up the names of types,
    and such.)  You can use SCOPE field to determine the scope
    that bound the name.  */
#define IDENTIFIER_BINDING(NODE) \
  (LANG_IDENTIFIER_CAST (NODE)->bindings)

/* TREE_TYPE only indicates on local and class scope the current
   type. For namespace scope, the presence of a type in any namespace
   is indicated with global_type_node, and the real type behind must
   be found through lookup.  */
#define IDENTIFIER_TYPE_VALUE(NODE) identifier_type_value (NODE)
#define REAL_IDENTIFIER_TYPE_VALUE(NODE) TREE_TYPE (NODE)
#define SET_IDENTIFIER_TYPE_VALUE(NODE,TYPE) (TREE_TYPE (NODE) = (TYPE))
#define IDENTIFIER_HAS_TYPE_VALUE(NODE) (IDENTIFIER_TYPE_VALUE (NODE) ? 1 : 0)

#define IDENTIFIER_LABEL_VALUE(NODE) \
  (LANG_IDENTIFIER_CAST (NODE)->label_value)
#define SET_IDENTIFIER_LABEL_VALUE(NODE, VALUE)   \
  IDENTIFIER_LABEL_VALUE (NODE) = (VALUE)

/* Nonzero if this identifier is used as a virtual function name somewhere
   (optimizes searches).  */
#define IDENTIFIER_VIRTUAL_P(NODE) TREE_LANG_FLAG_1 (NODE)

/* Nonzero if this identifier is the prefix for a mangled C++ operator
   name.  */
#define IDENTIFIER_OPNAME_P(NODE) TREE_LANG_FLAG_2 (NODE)

/* Nonzero if this identifier is the name of a type-conversion
   operator.  */
#define IDENTIFIER_TYPENAME_P(NODE) \
  TREE_LANG_FLAG_4 (NODE)

/* Nonzero if this identifier is the name of a constructor or
   destructor.  */
#define IDENTIFIER_CTOR_OR_DTOR_P(NODE) \
  TREE_LANG_FLAG_3 (NODE)

/* True iff NAME is the DECL_ASSEMBLER_NAME for an entity with vague
   linkage which the prelinker has assigned to this translation
   unit.  */
#define IDENTIFIER_REPO_CHOSEN(NAME) \
  (TREE_LANG_FLAG_6 (NAME))

/* In a RECORD_TYPE or UNION_TYPE, nonzero if any component is read-only.  */
#define C_TYPE_FIELDS_READONLY(TYPE) \
  (LANG_TYPE_CLASS_CHECK (TYPE)->fields_readonly)

/* The tokens stored in the default argument.  */

#define DEFARG_TOKENS(NODE) \
  (((struct tree_default_arg *)DEFAULT_ARG_CHECK (NODE))->tokens)
#define DEFARG_INSTANTIATIONS(NODE) \
  (((struct tree_default_arg *)DEFAULT_ARG_CHECK (NODE))->instantiations)

struct GTY (()) tree_default_arg {
  struct tree_common common;
  struct cp_token_cache *tokens;
  vec<tree, va_gc> *instantiations;
};


#define DEFERRED_NOEXCEPT_PATTERN(NODE) \
  (((struct tree_deferred_noexcept *)DEFERRED_NOEXCEPT_CHECK (NODE))->pattern)
#define DEFERRED_NOEXCEPT_ARGS(NODE) \
  (((struct tree_deferred_noexcept *)DEFERRED_NOEXCEPT_CHECK (NODE))->args)
#define DEFERRED_NOEXCEPT_SPEC_P(NODE)				\
  ((NODE) && (TREE_PURPOSE (NODE))				\
   && (TREE_CODE (TREE_PURPOSE (NODE)) == DEFERRED_NOEXCEPT))
#define UNEVALUATED_NOEXCEPT_SPEC_P(NODE)				\
  (DEFERRED_NOEXCEPT_SPEC_P (NODE)					\
   && DEFERRED_NOEXCEPT_PATTERN (TREE_PURPOSE (NODE)) == NULL_TREE)

struct GTY (()) tree_deferred_noexcept {
  struct tree_base base;
  tree pattern;
  tree args;
};


/* The condition associated with the static assertion.  This must be
   an integral constant expression.  */
#define STATIC_ASSERT_CONDITION(NODE) \
  (((struct tree_static_assert *)STATIC_ASSERT_CHECK (NODE))->condition)

/* The message associated with the static assertion.  This must be a
   string constant, which will be emitted as an error message when the
   static assert condition is false.  */
#define STATIC_ASSERT_MESSAGE(NODE) \
  (((struct tree_static_assert *)STATIC_ASSERT_CHECK (NODE))->message)

/* Source location information for a static assertion.  */
#define STATIC_ASSERT_SOURCE_LOCATION(NODE) \
  (((struct tree_static_assert *)STATIC_ASSERT_CHECK (NODE))->location)

struct GTY (()) tree_static_assert {
  struct tree_common common;
  tree condition;
  tree message;
  location_t location;
};

struct GTY (()) tree_argument_pack_select {
  struct tree_common common;
  tree argument_pack;
  int index;
};

/* The different kinds of traits that we encounter.  */

enum cp_trait_kind
{
  CPTK_BASES,
  CPTK_DIRECT_BASES,
  CPTK_HAS_NOTHROW_ASSIGN,
  CPTK_HAS_NOTHROW_CONSTRUCTOR,
  CPTK_HAS_NOTHROW_COPY,
  CPTK_HAS_TRIVIAL_ASSIGN,
  CPTK_HAS_TRIVIAL_CONSTRUCTOR,
  CPTK_HAS_TRIVIAL_COPY,
  CPTK_HAS_TRIVIAL_DESTRUCTOR,
  CPTK_HAS_UNIQUE_OBJ_REPRESENTATIONS,
  CPTK_HAS_VIRTUAL_DESTRUCTOR,
  CPTK_IS_ABSTRACT,
  CPTK_IS_AGGREGATE,
  CPTK_IS_BASE_OF,
  CPTK_IS_CLASS,
  CPTK_IS_EMPTY,
  CPTK_IS_ENUM,
  CPTK_IS_FINAL,
  CPTK_IS_LITERAL_TYPE,
  CPTK_IS_POD,
  CPTK_IS_POLYMORPHIC,
  CPTK_IS_SAME_AS,
  CPTK_IS_STD_LAYOUT,
  CPTK_IS_TRIVIAL,
  CPTK_IS_TRIVIALLY_ASSIGNABLE,
  CPTK_IS_TRIVIALLY_CONSTRUCTIBLE,
  CPTK_IS_TRIVIALLY_COPYABLE,
  CPTK_IS_UNION,
  CPTK_UNDERLYING_TYPE
};

/* The types that we are processing.  */
#define TRAIT_EXPR_TYPE1(NODE) \
  (((struct tree_trait_expr *)TRAIT_EXPR_CHECK (NODE))->type1)

#define TRAIT_EXPR_TYPE2(NODE) \
  (((struct tree_trait_expr *)TRAIT_EXPR_CHECK (NODE))->type2)

/* The specific trait that we are processing.  */
#define TRAIT_EXPR_KIND(NODE) \
  (((struct tree_trait_expr *)TRAIT_EXPR_CHECK (NODE))->kind)

struct GTY (()) tree_trait_expr {
  struct tree_common common;
  tree type1;
  tree type2;  
  enum cp_trait_kind kind;
};

/* Based off of TYPE_UNNAMED_P.  */
#define LAMBDA_TYPE_P(NODE) \
  (CLASS_TYPE_P (NODE) && CLASSTYPE_LAMBDA_EXPR (NODE))

/* Test if FUNCTION_DECL is a lambda function.  */
#define LAMBDA_FUNCTION_P(FNDECL) \
  (DECL_OVERLOADED_OPERATOR_P (FNDECL) == CALL_EXPR \
   && LAMBDA_TYPE_P (CP_DECL_CONTEXT (FNDECL)))

enum cp_lambda_default_capture_mode_type {
  CPLD_NONE,
  CPLD_COPY,
  CPLD_REFERENCE
};

/* The method of default capture, if any.  */
#define LAMBDA_EXPR_DEFAULT_CAPTURE_MODE(NODE) \
  (((struct tree_lambda_expr *)LAMBDA_EXPR_CHECK (NODE))->default_capture_mode)

/* The capture-list, including `this'.  Each capture is stored as a FIELD_DECL
 * so that the name, type, and field are all together, whether or not it has
 * been added to the lambda's class type.
   TREE_LIST:
     TREE_PURPOSE: The FIELD_DECL for this capture.
     TREE_VALUE: The initializer. This is part of a GNU extension.  */
#define LAMBDA_EXPR_CAPTURE_LIST(NODE) \
  (((struct tree_lambda_expr *)LAMBDA_EXPR_CHECK (NODE))->capture_list)

/* During parsing of the lambda-introducer, the node in the capture-list
   that holds the 'this' capture.  During parsing of the body, the
   capture proxy for that node.  */
#define LAMBDA_EXPR_THIS_CAPTURE(NODE) \
  (((struct tree_lambda_expr *)LAMBDA_EXPR_CHECK (NODE))->this_capture)

/* Predicate tracking whether `this' is in the effective capture set.  */
#define LAMBDA_EXPR_CAPTURES_THIS_P(NODE) \
  LAMBDA_EXPR_THIS_CAPTURE(NODE)

/* Predicate tracking whether the lambda was declared 'mutable'.  */
#define LAMBDA_EXPR_MUTABLE_P(NODE) \
  TREE_LANG_FLAG_1 (LAMBDA_EXPR_CHECK (NODE))

/* The return type in the expression.
 * NULL_TREE indicates that none was specified.  */
#define LAMBDA_EXPR_RETURN_TYPE(NODE) \
  (((struct tree_lambda_expr *)LAMBDA_EXPR_CHECK (NODE))->return_type)

/* The source location of the lambda.  */
#define LAMBDA_EXPR_LOCATION(NODE) \
  (((struct tree_lambda_expr *)LAMBDA_EXPR_CHECK (NODE))->locus)

/* The mangling scope for the lambda: FUNCTION_DECL, PARM_DECL, VAR_DECL,
   FIELD_DECL or NULL_TREE.  If this is NULL_TREE, we have no linkage.  */
#define LAMBDA_EXPR_EXTRA_SCOPE(NODE) \
  (((struct tree_lambda_expr *)LAMBDA_EXPR_CHECK (NODE))->extra_scope)

/* If EXTRA_SCOPE, this is the number of the lambda within that scope.  */
#define LAMBDA_EXPR_DISCRIMINATOR(NODE) \
  (((struct tree_lambda_expr *)LAMBDA_EXPR_CHECK (NODE))->discriminator)

/* During parsing of the lambda, a vector of capture proxies which need
   to be pushed once we're done processing a nested lambda.  */
#define LAMBDA_EXPR_PENDING_PROXIES(NODE) \
  (((struct tree_lambda_expr *)LAMBDA_EXPR_CHECK (NODE))->pending_proxies)

/* The closure type of the lambda.  Note that the TREE_TYPE of a
   LAMBDA_EXPR is always NULL_TREE, because we need to instantiate the
   LAMBDA_EXPR in order to instantiate the type.  */
#define LAMBDA_EXPR_CLOSURE(NODE) \
  (((struct tree_lambda_expr *)LAMBDA_EXPR_CHECK (NODE))->closure)

struct GTY (()) tree_lambda_expr
{
  struct tree_typed typed;
  tree capture_list;
  tree this_capture;
  tree return_type;
  tree extra_scope;
  tree closure;
  vec<tree, va_gc> *pending_proxies;
  location_t locus;
  enum cp_lambda_default_capture_mode_type default_capture_mode;
  int discriminator;
};

/* A (typedef,context,usage location) triplet.
   It represents a typedef used through a
   context at a given source location.
   e.g.
   struct foo {
     typedef int myint;
   };

   struct bar {
    foo::myint v; // #1<-- this location.
   };

   In bar, the triplet will be (myint, foo, #1).
   */
struct GTY(()) qualified_typedef_usage_s {
  tree typedef_decl;
  tree context;
  location_t locus;
};
typedef struct qualified_typedef_usage_s qualified_typedef_usage_t;

/* Non-zero if this template specialization has access violations that
   should be rechecked when the function is instantiated outside argument
   deduction.  */
#define TINFO_HAS_ACCESS_ERRORS(NODE) \
  (TREE_LANG_FLAG_0 (TEMPLATE_INFO_CHECK (NODE)))
#define FNDECL_HAS_ACCESS_ERRORS(NODE) \
  (TINFO_HAS_ACCESS_ERRORS (DECL_TEMPLATE_INFO (NODE)))

/* Non-zero if this variable template specialization was specified using a
   template-id, so it's a partial or full specialization and not a definition
   of the member template of a particular class specialization.  */
#define TINFO_USED_TEMPLATE_ID(NODE) \
  (TREE_LANG_FLAG_1 (TEMPLATE_INFO_CHECK (NODE)))

struct GTY(()) tree_template_info {
  struct tree_common common;
  vec<qualified_typedef_usage_t, va_gc> *typedefs_needing_access_checking;
};

// Constraint information for a C++ declaration. Constraint information is
// comprised of:
//
// - a constraint expression introduced by the template header
// - a constraint expression introduced by a function declarator
// - the associated constraints, which are the conjunction of those,
//   and used for declaration matching
//
// The template and declarator requirements are kept to support pretty
// printing constrained declarations.
struct GTY(()) tree_constraint_info {
  struct tree_base base;
  tree template_reqs;
  tree declarator_reqs;
  tree associated_constr;
};

// Require that pointer P is non-null before returning.
template<typename T>
inline T*
check_nonnull (T* p)
{
  gcc_assert (p);
  return p;
}

// Returns true iff T is non-null and represents constraint info.
inline tree_constraint_info *
check_constraint_info (tree t)
{
  if (t && TREE_CODE (t) == CONSTRAINT_INFO)
    return (tree_constraint_info *)t;
  return NULL;
}

// Access the expression describing the template constraints. This may be
// null if no constraints were introduced in the template parameter list,
// a requirements clause after the template parameter list, or constraints
// through a constrained-type-specifier.
#define CI_TEMPLATE_REQS(NODE) \
  check_constraint_info (check_nonnull(NODE))->template_reqs

// Access the expression describing the trailing constraints. This is non-null
// for any implicit instantiation of a constrained declaration. For a
// templated declaration it is non-null only when a trailing requires-clause
// was specified.
#define CI_DECLARATOR_REQS(NODE) \
  check_constraint_info (check_nonnull(NODE))->declarator_reqs

// The computed associated constraint expression for a declaration.
#define CI_ASSOCIATED_CONSTRAINTS(NODE) \
  check_constraint_info (check_nonnull(NODE))->associated_constr

// Access the logical constraints on the template parameters introduced
// at a given template parameter list level indicated by NODE.
#define TEMPLATE_PARMS_CONSTRAINTS(NODE) \
  TREE_TYPE (TREE_LIST_CHECK (NODE))

// Access the logical constraints on the template parameter declaration
// indicated by NODE.
#define TEMPLATE_PARM_CONSTRAINTS(NODE) \
  TREE_TYPE (TREE_LIST_CHECK (NODE))

/* Non-zero if the noexcept is present in a compound requirement. */
#define COMPOUND_REQ_NOEXCEPT_P(NODE) \
  TREE_LANG_FLAG_0 (TREE_CHECK (NODE, COMPOUND_REQ))

/* The constraints on an 'auto' placeholder type, used in an argument deduction
   constraint.  */
#define PLACEHOLDER_TYPE_CONSTRAINTS(NODE) \
  DECL_SIZE_UNIT (TYPE_NAME (NODE))

/* The expression evaluated by the predicate constraint. */
#define PRED_CONSTR_EXPR(NODE) \
  TREE_OPERAND (TREE_CHECK (NODE, PRED_CONSTR), 0)

/* The concept of a concept check. */
#define CHECK_CONSTR_CONCEPT(NODE) \
  TREE_OPERAND (TREE_CHECK (NODE, CHECK_CONSTR), 0)

/* The template arguments of a concept check. */
#define CHECK_CONSTR_ARGS(NODE) \
  TREE_OPERAND (TREE_CHECK (NODE, CHECK_CONSTR), 1)

/* The expression validated by the predicate constraint. */
#define EXPR_CONSTR_EXPR(NODE) \
  TREE_OPERAND (TREE_CHECK (NODE, EXPR_CONSTR), 0)

/* The type validated by the predicate constraint. */
#define TYPE_CONSTR_TYPE(NODE) \
  TREE_OPERAND (TREE_CHECK (NODE, TYPE_CONSTR), 0)

/* In an implicit conversion constraint, the source expression. */
#define ICONV_CONSTR_EXPR(NODE) \
  TREE_OPERAND (TREE_CHECK (NODE, ICONV_CONSTR), 0)

/* In an implicit conversion constraint, the target type. */
#define ICONV_CONSTR_TYPE(NODE) \
  TREE_OPERAND (TREE_CHECK (NODE, ICONV_CONSTR), 1)

/* In an argument deduction constraint, the source expression. */
#define DEDUCT_CONSTR_EXPR(NODE) \
  TREE_OPERAND (TREE_CHECK (NODE, DEDUCT_CONSTR), 0)

/* In an argument deduction constraint, the target type pattern. */
#define DEDUCT_CONSTR_PATTERN(NODE) \
  TREE_OPERAND (TREE_CHECK (NODE, DEDUCT_CONSTR), 1)

/* In an argument deduction constraint, the list of placeholder nodes. */
#define DEDUCT_CONSTR_PLACEHOLDER(NODE) \
  TREE_OPERAND (TREE_CHECK (NODE, DEDUCT_CONSTR), 2)

/* The expression of an exception constraint. */
#define EXCEPT_CONSTR_EXPR(NODE) \
  TREE_OPERAND (TREE_CHECK (NODE, EXCEPT_CONSTR), 0)

/* In a parameterized constraint, the local parameters. */
#define PARM_CONSTR_PARMS(NODE) \
  TREE_OPERAND (TREE_CHECK (NODE, PARM_CONSTR), 0)

/* In a parameterized constraint, the operand. */
#define PARM_CONSTR_OPERAND(NODE) \
  TREE_OPERAND (TREE_CHECK (NODE, PARM_CONSTR), 1)

/* Whether a PARM_DECL represents a local parameter in a
   requires-expression.  */
#define CONSTRAINT_VAR_P(NODE) \
  DECL_LANG_FLAG_2 (TREE_CHECK (NODE, PARM_DECL))

/* The concept constraining this constrained template-parameter.  */
#define CONSTRAINED_PARM_CONCEPT(NODE) \
  DECL_SIZE_UNIT (TYPE_DECL_CHECK (NODE))
/* Any extra template arguments specified for a constrained
   template-parameter.  */
#define CONSTRAINED_PARM_EXTRA_ARGS(NODE) \
  DECL_SIZE (TYPE_DECL_CHECK (NODE))
/* The first template parameter of CONSTRAINED_PARM_CONCEPT to be used as a
   prototype for the constrained parameter in finish_shorthand_constraint,
   attached for convenience.  */
#define CONSTRAINED_PARM_PROTOTYPE(NODE) \
  DECL_INITIAL (TYPE_DECL_CHECK (NODE))

enum cp_tree_node_structure_enum {
  TS_CP_GENERIC,
  TS_CP_IDENTIFIER,
  TS_CP_TPI,
  TS_CP_PTRMEM,
  TS_CP_BINDING,
  TS_CP_OVERLOAD,
  TS_CP_BASELINK,
  TS_CP_TEMPLATE_DECL,
  TS_CP_WRAPPER,
  TS_CP_DEFAULT_ARG,
  TS_CP_DEFERRED_NOEXCEPT,
  TS_CP_STATIC_ASSERT,
  TS_CP_ARGUMENT_PACK_SELECT,
  TS_CP_TRAIT_EXPR,
  TS_CP_LAMBDA_EXPR,
  TS_CP_TEMPLATE_INFO,
  TS_CP_CONSTRAINT_INFO,
  TS_CP_USERDEF_LITERAL,
  LAST_TS_CP_ENUM
};

/* The resulting tree type.  */
union GTY((desc ("cp_tree_node_structure (&%h)"),
       chain_next ("(union lang_tree_node *) c_tree_chain_next (&%h.generic)"))) lang_tree_node {
  union tree_node GTY ((tag ("TS_CP_GENERIC"),
			desc ("tree_node_structure (&%h)"))) generic;
  struct template_parm_index GTY ((tag ("TS_CP_TPI"))) tpi;
  struct ptrmem_cst GTY ((tag ("TS_CP_PTRMEM"))) ptrmem;
  struct tree_overload GTY ((tag ("TS_CP_OVERLOAD"))) overload;
  struct tree_baselink GTY ((tag ("TS_CP_BASELINK"))) baselink;
  struct tree_template_decl GTY ((tag ("TS_CP_TEMPLATE_DECL"))) template_decl;
  struct tree_default_arg GTY ((tag ("TS_CP_DEFAULT_ARG"))) default_arg;
  struct tree_deferred_noexcept GTY ((tag ("TS_CP_DEFERRED_NOEXCEPT"))) deferred_noexcept;
  struct lang_identifier GTY ((tag ("TS_CP_IDENTIFIER"))) identifier;
  struct tree_static_assert GTY ((tag ("TS_CP_STATIC_ASSERT"))) 
    static_assertion;
  struct tree_argument_pack_select GTY ((tag ("TS_CP_ARGUMENT_PACK_SELECT")))
    argument_pack_select;
  struct tree_trait_expr GTY ((tag ("TS_CP_TRAIT_EXPR")))
    trait_expression;
  struct tree_lambda_expr GTY ((tag ("TS_CP_LAMBDA_EXPR")))
    lambda_expression;
  struct tree_template_info GTY ((tag ("TS_CP_TEMPLATE_INFO")))
    template_info;
  struct tree_constraint_info GTY ((tag ("TS_CP_CONSTRAINT_INFO")))
    constraint_info;
  struct tree_userdef_literal GTY ((tag ("TS_CP_USERDEF_LITERAL")))
    userdef_literal;
};