xref: /netbsd-src/external/gpl3/gcc.old/dist/gcc/cp/cp-tree.def (revision c3ab26950fe8540fb553d1d1dcae454bc98e5a25)
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, 1988, 1990, 1993, 1997, 1998, 2003, 2004, 2005,
5   1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007
6   Free Software Foundation, Inc.
7   Hacked by Michael Tiemann (tiemann@cygnus.com)
8
9This file is part of GCC.
10
11GCC is free software; you can redistribute it and/or modify
12it under the terms of the GNU General Public License as published by
13the Free Software Foundation; either version 3, or (at your option)
14any later version.
15
16GCC is distributed in the hope that it will be useful,
17but WITHOUT ANY WARRANTY; without even the implied warranty of
18MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19GNU General Public License for more details.
20
21You should have received a copy of the GNU General Public License
22along with GCC; see the file COPYING3.  If not see
23<http://www.gnu.org/licenses/>.  */
24
25
26/* An OFFSET_REF is used in two situations:
27
28   1. An expression of the form `A::m' where `A' is a class and `m' is
29      a non-static member.  In this case, operand 0 will be a TYPE
30      (corresponding to `A') and operand 1 will be a FIELD_DECL,
31      BASELINK, or TEMPLATE_ID_EXPR (corresponding to `m').
32
33      The expression is a pointer-to-member if its address is taken,
34      but simply denotes a member of the object if its address is not
35      taken.
36
37      This form is only used during the parsing phase; once semantic
38      analysis has taken place they are eliminated.
39
40   2. An expression of the form `x.*p'.  In this case, operand 0 will
41      be an expression corresponding to `x' and operand 1 will be an
42      expression with pointer-to-member type.  */
43DEFTREECODE (OFFSET_REF, "offset_ref", tcc_reference, 2)
44
45/* A pointer-to-member constant.  For a pointer-to-member constant
46   `X::Y' The PTRMEM_CST_CLASS is the RECORD_TYPE for `X' and the
47   PTRMEM_CST_MEMBER is the _DECL for `Y'.  */
48DEFTREECODE (PTRMEM_CST, "ptrmem_cst", tcc_constant, 0)
49
50/* For NEW_EXPR, operand 0 is the placement list.
51   Operand 1 is the new-declarator.
52   Operand 2 is the number of elements in the array.
53   Operand 3 is the initializer.  */
54DEFTREECODE (NEW_EXPR, "nw_expr", tcc_expression, 4)
55DEFTREECODE (VEC_NEW_EXPR, "vec_nw_expr", tcc_expression, 3)
56
57/* For DELETE_EXPR, operand 0 is the store to be destroyed.
58   Operand 1 is the value to pass to the destroying function
59   saying whether the store should be deallocated as well.  */
60DEFTREECODE (DELETE_EXPR, "dl_expr", tcc_expression, 2)
61DEFTREECODE (VEC_DELETE_EXPR, "vec_dl_expr", tcc_expression, 2)
62
63/* Value is reference to particular overloaded class method.
64   Operand 0 is the class, operand 1 is the field
65   The COMPLEXITY field holds the class level (usually 0).  */
66DEFTREECODE (SCOPE_REF, "scope_ref", tcc_reference, 2)
67
68/* When composing an object with a member, this is the result.
69   Operand 0 is the object.  Operand 1 is the member (usually
70   a dereferenced pointer to member).  */
71DEFTREECODE (MEMBER_REF, "member_ref", tcc_reference, 2)
72
73/* Type conversion operator in C++.  TREE_TYPE is type that this
74   operator converts to.  Operand is expression to be converted.  */
75DEFTREECODE (TYPE_EXPR, "type_expr", tcc_expression, 1)
76
77/* AGGR_INIT_EXPRs have a variably-sized representation similar to
78   that of CALL_EXPRs.  Operand 0 is an INTEGER_CST node containing the
79   operand count, operand 1 is the function which performs initialization,
80   operand 2 is the slot which was allocated for this expression, and
81   the remaining operands are the arguments to the initialization function.  */
82DEFTREECODE (AGGR_INIT_EXPR, "aggr_init_expr", tcc_vl_exp, 3)
83
84/* Initialization of an array from another array, expressed at a high level
85   so that it works with TARGET_EXPR.  Operand 0 is the target, operand 1
86   is the initializer.  */
87DEFTREECODE (VEC_INIT_EXPR, "vec_init_expr", tcc_expression, 2)
88
89/* A throw expression.  operand 0 is the expression, if there was one,
90   else it is NULL_TREE.  */
91DEFTREECODE (THROW_EXPR, "throw_expr", tcc_expression, 1)
92
93/* An empty class object.  The TREE_TYPE gives the class type.  We use
94   these to avoid actually creating instances of the empty classes.  */
95DEFTREECODE (EMPTY_CLASS_EXPR, "empty_class_expr", tcc_expression, 0)
96
97/* A reference to a member function or member functions from a base
98   class.  BASELINK_FUNCTIONS gives the FUNCTION_DECL,
99   TEMPLATE_DECL, OVERLOAD, or TEMPLATE_ID_EXPR corresponding to the
100   functions.  BASELINK_BINFO gives the base from which the functions
101   come, i.e., the base to which the `this' pointer must be converted
102   before the functions are called.  BASELINK_ACCESS_BINFO gives the
103   base used to name the functions.
104
105   A BASELINK is an expression; the TREE_TYPE of the BASELINK gives
106   the type of the expression.  This type is either a FUNCTION_TYPE,
107   METHOD_TYPE, or `unknown_type_node' indicating that the function is
108   overloaded.  */
109DEFTREECODE (BASELINK, "baselink", tcc_exceptional, 0)
110
111/* Template definition.  The following fields have the specified uses,
112   although there are other macros in cp-tree.h that should be used for
113   accessing this data.
114	DECL_ARGUMENTS		template parm vector
115	DECL_TEMPLATE_INFO      template text &c
116	DECL_VINDEX		list of instantiations already produced;
117				only done for functions so far
118   For class template:
119	DECL_INITIAL		associated templates (methods &c)
120	DECL_TEMPLATE_RESULT    null
121   For non-class templates:
122	TREE_TYPE		type of object to be constructed
123	DECL_TEMPLATE_RESULT    decl for object to be created
124				(e.g., FUNCTION_DECL with tmpl parms used)
125 */
126DEFTREECODE (TEMPLATE_DECL, "template_decl", tcc_declaration, 0)
127
128/* Index into a template parameter list.  The TEMPLATE_PARM_IDX gives
129   the index (from 0) of the parameter, while the TEMPLATE_PARM_LEVEL
130   gives the level (from 1) of the parameter.
131
132   Here's an example:
133
134   template <class T> // Index 0, Level 1.
135   struct S
136   {
137      template <class U, // Index 0, Level 2.
138		class V> // Index 1, Level 2.
139      void f();
140   };
141
142   The DESCENDANTS will be a chain of TEMPLATE_PARM_INDEXs descended
143   from this one.  The first descendant will have the same IDX, but
144   its LEVEL will be one less.  The TREE_CHAIN field is used to chain
145   together the descendants.  The TEMPLATE_PARM_DECL is the
146   declaration of this parameter, either a TYPE_DECL or CONST_DECL.
147   The TEMPLATE_PARM_ORIG_LEVEL is the LEVEL of the most distant
148   parent, i.e., the LEVEL that the parameter originally had when it
149   was declared.  For example, if we instantiate S<int>, we will have:
150
151   struct S<int>
152   {
153     template <class U, // Index 0, Level 1, Orig Level 2
154	       class V> // Index 1, Level 1, Orig Level 2
155     void f();
156   };
157
158   The LEVEL is the level of the parameter when we are worrying about
159   the types of things; the ORIG_LEVEL is the level when we are
160   worrying about instantiating things.  */
161DEFTREECODE (TEMPLATE_PARM_INDEX, "template_parm_index", tcc_exceptional, 0)
162
163/* Index into a template parameter list for template template parameters.
164   This parameter must be a type.  The TYPE_FIELDS value will be a
165   TEMPLATE_PARM_INDEX.
166
167   It is used without template arguments like TT in C<TT>,
168   TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO is NULL_TREE
169   and TYPE_NAME is a TEMPLATE_DECL.  */
170DEFTREECODE (TEMPLATE_TEMPLATE_PARM, "template_template_parm", tcc_type, 0)
171
172/* The ordering of the following codes is optimized for the checking
173   macros in tree.h.  Changing the order will degrade the speed of the
174   compiler.  TEMPLATE_TYPE_PARM, TYPENAME_TYPE, TYPEOF_TYPE,
175   BOUND_TEMPLATE_TEMPLATE_PARM.  */
176
177/* Index into a template parameter list.  This parameter must be a type.
178   The type.values field will be a TEMPLATE_PARM_INDEX.  */
179DEFTREECODE (TEMPLATE_TYPE_PARM, "template_type_parm", tcc_type, 0)
180
181/* A type designated by `typename T::t'.  TYPE_CONTEXT is `T',
182   TYPE_NAME is an IDENTIFIER_NODE for `t'.  If the type was named via
183   template-id, TYPENAME_TYPE_FULLNAME will hold the TEMPLATE_ID_EXPR.
184   TREE_TYPE is always NULL.  */
185DEFTREECODE (TYPENAME_TYPE, "typename_type", tcc_type, 0)
186
187/* A type designated by `__typeof (expr)'.  TYPEOF_TYPE_EXPR is the
188   expression in question.  */
189DEFTREECODE (TYPEOF_TYPE, "typeof_type", tcc_type, 0)
190
191/* Like TEMPLATE_TEMPLATE_PARM it is used with bound template arguments
192   like TT<int>.
193   In this case, TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO contains the
194   template name and its bound arguments.  TYPE_NAME is a TYPE_DECL.  */
195DEFTREECODE (BOUND_TEMPLATE_TEMPLATE_PARM, "bound_template_template_parm",
196	     tcc_type, 0)
197
198/* For template template argument of the form `T::template C'.
199   TYPE_CONTEXT is `T', the template parameter dependent object.
200   TYPE_NAME is an IDENTIFIER_NODE for `C', the member class template.  */
201DEFTREECODE (UNBOUND_CLASS_TEMPLATE, "unbound_class_template", tcc_type, 0)
202
203/* A using declaration.  USING_DECL_SCOPE contains the specified
204   scope.  In a member using decl, unless DECL_DEPENDENT_P is true,
205   USING_DECL_DECLS contains the _DECL or OVERLOAD so named.  This is
206   not an alias, but is later expanded into multiple aliases.  */
207DEFTREECODE (USING_DECL, "using_decl", tcc_declaration, 0)
208
209/* A using directive. The operand is USING_STMT_NAMESPACE.  */
210DEFTREECODE (USING_STMT, "using_directive", tcc_statement, 1)
211
212/* An un-parsed default argument.  Holds a vector of input tokens and
213   a vector of places where the argument was instantiated before
214   parsing had occurred.  */
215DEFTREECODE (DEFAULT_ARG, "default_arg", tcc_exceptional, 0)
216
217/* A template-id, like foo<int>.  The first operand is the template.
218   The second is NULL if there are no explicit arguments, or a
219   TREE_VEC of arguments.  The template will be a FUNCTION_DECL,
220   TEMPLATE_DECL, or an OVERLOAD.  If the template-id refers to a
221   member template, the template may be an IDENTIFIER_NODE.  */
222DEFTREECODE (TEMPLATE_ID_EXPR, "template_id_expr", tcc_expression, 2)
223
224/* A list-like node for chaining overloading candidates. TREE_TYPE is
225   the original name, and the parameter is the FUNCTION_DECL.  */
226DEFTREECODE (OVERLOAD, "overload", tcc_exceptional, 0)
227
228/* A pseudo-destructor, of the form "OBJECT.~DESTRUCTOR" or
229   "OBJECT.SCOPE::~DESTRUCTOR.  The first operand is the OBJECT.  The
230   second operand (if non-NULL) is the SCOPE.  The third operand is
231   the TYPE node corresponding to the DESTRUCTOR.  The type of the
232   first operand will always be a scalar type.
233
234   The type of a PSEUDO_DTOR_EXPR is always "void", even though it can
235   be used as if it were a zero-argument function.  We handle the
236   function-call case specially, and giving it "void" type prevents it
237   being used in expressions in ways that are not permitted.  */
238DEFTREECODE (PSEUDO_DTOR_EXPR, "pseudo_dtor_expr", tcc_expression, 3)
239
240/* A whole bunch of tree codes for the initial, superficial parsing of
241   templates.  */
242DEFTREECODE (MODOP_EXPR, "modop_expr", tcc_expression, 3)
243DEFTREECODE (CAST_EXPR, "cast_expr", tcc_unary, 1)
244DEFTREECODE (REINTERPRET_CAST_EXPR, "reinterpret_cast_expr", tcc_unary, 1)
245DEFTREECODE (CONST_CAST_EXPR, "const_cast_expr", tcc_unary, 1)
246DEFTREECODE (STATIC_CAST_EXPR, "static_cast_expr", tcc_unary, 1)
247DEFTREECODE (DYNAMIC_CAST_EXPR, "dynamic_cast_expr", tcc_unary, 1)
248DEFTREECODE (DOTSTAR_EXPR, "dotstar_expr", tcc_expression, 2)
249DEFTREECODE (TYPEID_EXPR, "typeid_expr", tcc_expression, 1)
250
251/* A placeholder for an expression that is not type-dependent, but
252   does occur in a template.  When an expression that is not
253   type-dependent appears in a larger expression, we must compute the
254   type of that larger expression.  That computation would normally
255   modify the original expression, which would change the mangling of
256   that expression if it appeared in a template argument list.  In
257   that situation, we create a NON_DEPENDENT_EXPR to take the place of
258   the original expression.  The expression is the only operand -- it
259   is only needed for diagnostics.  */
260DEFTREECODE (NON_DEPENDENT_EXPR, "non_dependent_expr", tcc_expression, 1)
261
262/* CTOR_INITIALIZER is a placeholder in template code for a call to
263   setup_vtbl_pointer (and appears in all functions, not just ctors).  */
264DEFTREECODE (CTOR_INITIALIZER, "ctor_initializer", tcc_expression, 1)
265
266DEFTREECODE (TRY_BLOCK, "try_block", tcc_statement, 2)
267
268DEFTREECODE (EH_SPEC_BLOCK, "eh_spec_block", tcc_statement, 2)
269
270/* A HANDLER wraps a catch handler for the HANDLER_TYPE.  If this is
271   CATCH_ALL_TYPE, then the handler catches all types.  The declaration of
272   the catch variable is in HANDLER_PARMS, and the body block in
273   HANDLER_BODY.  */
274DEFTREECODE (HANDLER, "handler", tcc_statement, 2)
275
276/* A MUST_NOT_THROW_EXPR wraps an expression that may not
277   throw, and must call terminate if it does.  */
278DEFTREECODE (MUST_NOT_THROW_EXPR, "must_not_throw_expr", tcc_expression, 1)
279
280/* A CLEANUP_STMT marks the point at which a declaration is fully
281   constructed.  The CLEANUP_EXPR is run on behalf of CLEANUP_DECL
282   when CLEANUP_BODY completes.  */
283DEFTREECODE (CLEANUP_STMT, "cleanup_stmt", tcc_statement, 3)
284
285/* Represents an 'if' statement. The operands are IF_COND,
286   THEN_CLAUSE, and ELSE_CLAUSE, respectively.  */
287/* ??? It is currently still necessary to distinguish between IF_STMT
288   and COND_EXPR for the benefit of templates.  */
289DEFTREECODE (IF_STMT, "if_stmt", tcc_statement, 3)
290
291/* Used to represent a `for' statement. The operands are
292   FOR_INIT_STMT, FOR_COND, FOR_EXPR, and FOR_BODY, respectively.  */
293DEFTREECODE (FOR_STMT, "for_stmt", tcc_statement, 4)
294
295/* Used to represent a 'while' statement. The operands are WHILE_COND
296   and WHILE_BODY, respectively.  */
297DEFTREECODE (WHILE_STMT, "while_stmt", tcc_statement, 2)
298
299/* Used to represent a 'do' statement. The operands are DO_BODY and
300   DO_COND, respectively.  */
301DEFTREECODE (DO_STMT, "do_stmt", tcc_statement, 2)
302
303/* Used to represent a 'break' statement.  */
304DEFTREECODE (BREAK_STMT, "break_stmt", tcc_statement, 0)
305
306/* Used to represent a 'continue' statement.  */
307DEFTREECODE (CONTINUE_STMT, "continue_stmt", tcc_statement, 0)
308
309/* Used to represent a 'switch' statement. The operands are
310   SWITCH_STMT_COND, SWITCH_STMT_BODY and SWITCH_STMT_TYPE, respectively.  */
311DEFTREECODE (SWITCH_STMT, "switch_stmt", tcc_statement, 3)
312
313/* Used to represent an expression statement.  Use `EXPR_STMT_EXPR' to
314   obtain the expression.  */
315DEFTREECODE (EXPR_STMT, "expr_stmt", tcc_expression, 1)
316
317DEFTREECODE (TAG_DEFN, "tag_defn", tcc_expression, 0)
318
319/* Represents an 'offsetof' expression during template expansion.  */
320DEFTREECODE (OFFSETOF_EXPR, "offsetof_expr", tcc_expression, 1)
321
322/* Represents a 'sizeof' expression during template expansion.  */
323DEFTREECODE (SIZEOF_EXPR, "sizeof_expr", tcc_expression, 1)
324
325/* Represents the -> operator during template expansion.  */
326DEFTREECODE (ARROW_EXPR, "arrow_expr", tcc_expression, 1)
327
328/* Represents an '__alignof__' expression during template
329   expansion.  */
330DEFTREECODE (ALIGNOF_EXPR, "alignof_expr", tcc_expression, 1)
331
332/* A STMT_EXPR represents a statement-expression during template
333   expansion.  This is the GCC extension { ( ... ) }.  The
334   STMT_EXPR_STMT is the statement given by the expression.  */
335DEFTREECODE (STMT_EXPR, "stmt_expr", tcc_expression, 1)
336
337/* Unary plus. Operand 0 is the expression to which the unary plus
338   is applied.  */
339DEFTREECODE (UNARY_PLUS_EXPR, "unary_plus_expr", tcc_unary, 1)
340
341/** C++0x extensions. */
342
343/* A static assertion.  This is a C++0x extension.
344   STATIC_ASSERT_CONDITION contains the condition that is being
345   checked.  STATIC_ASSERT_MESSAGE contains the message (a string
346   literal) to be displayed if the condition fails to hold.  */
347DEFTREECODE (STATIC_ASSERT, "static_assert", tcc_exceptional, 0)
348
349/* Represents an argument pack of types (or templates). An argument
350   pack stores zero or more arguments that will be used to instantiate
351   a parameter pack.
352
353   ARGUMENT_PACK_ARGS retrieves the arguments stored in the argument
354   pack.
355
356   Example:
357     template<typename... Values>
358     class tuple { ... };
359
360     tuple<int, float, double> t;
361
362   Values is a (template) parameter pack. When tuple<int, float,
363   double> is instantiated, the Values parameter pack is instantiated
364   with the argument pack <int, float, double>. ARGUMENT_PACK_ARGS will
365   be a TREE_VEC containing int, float, and double.  */
366DEFTREECODE (TYPE_ARGUMENT_PACK, "type_argument_pack", tcc_type, 0)
367
368/* Represents an argument pack of values, which can be used either for
369   non-type template arguments or function call arguments.
370
371   NONTYPE_ARGUMENT_PACK plays precisely the same role as
372   TYPE_ARGUMENT_PACK, but will be used for packing non-type template
373   arguments (e.g., "int... Dimensions") or function arguments ("const
374   Args&... args"). */
375DEFTREECODE (NONTYPE_ARGUMENT_PACK, "nontype_argument_pack", tcc_expression, 1)
376
377/* Represents a type expression that will be expanded into a list of
378   types when instantiated with one or more argument packs.
379
380   PACK_EXPANSION_PATTERN retrieves the expansion pattern. This is
381   the type or expression that we will substitute into with each
382   argument in an argument pack.
383
384   SET_PACK_EXPANSION_PATTERN sets the expansion pattern.
385
386   PACK_EXPANSION_PARAMETER_PACKS contains a TREE_LIST of the parameter
387   packs that are used in this pack expansion.
388
389   Example:
390     template<typename... Values>
391     struct tied : tuple<Values&...> {
392       // ...
393     };
394
395   The derivation from tuple contains a TYPE_PACK_EXPANSION for the
396   template arguments. Its PACK_EXPANSION_PATTERN is "Values&" and its
397   PACK_EXPANSION_PARAMETER_PACKS will contain "Values".  */
398DEFTREECODE (TYPE_PACK_EXPANSION, "type_pack_expansion", tcc_type, 0)
399
400/* Represents an expression that will be expanded into a list of
401   expressions when instantiated with one or more argument packs.
402
403   EXPR_PACK_EXPANSION plays precisely the same role as TYPE_PACK_EXPANSION,
404   but will be used for expressions.  */
405DEFTREECODE (EXPR_PACK_EXPANSION, "expr_pack_expansion", tcc_expression, 1)
406
407/* Selects the Ith parameter out of an argument pack. This node will
408   be used when instantiating pack expansions; see
409   tsubst_pack_expansion.
410
411   ARGUMENT_PACK_SELECT_FROM_PACK contains the *_ARGUMENT_PACK node
412   from which the argument will be selected.
413
414   ARGUMENT_PACK_SELECT_INDEX contains the index into the argument
415   pack that will be returned by this ARGUMENT_PACK_SELECT node. The
416   index is a machine integer.  */
417DEFTREECODE (ARGUMENT_PACK_SELECT, "argument_pack_select", tcc_exceptional, 0)
418
419/** C++ extensions. */
420
421/* Represents a trait expression during template expansion.  */
422DEFTREECODE (TRAIT_EXPR, "trait_expr", tcc_exceptional, 0)
423
424/* A lambda expression.  This is a C++0x extension.
425   LAMBDA_EXPR_DEFAULT_CAPTURE_MODE is an enum for the default, which may be
426   none.
427   LAMBDA_EXPR_CAPTURE_LIST holds the capture-list, including `this'.
428   LAMBDA_EXPR_THIS_CAPTURE goes straight to the capture of `this', if it exists.
429   LAMBDA_EXPR_MUTABLE_P signals whether this lambda was declared mutable.
430   LAMBDA_EXPR_RETURN_TYPE holds the return type, if it was specified.  */
431DEFTREECODE (LAMBDA_EXPR, "lambda_expr", tcc_exceptional, 0)
432
433/* The declared type of an expression.  This is a C++0x extension.
434   DECLTYPE_TYPE_EXPR is the expression whose type we are computing.
435   DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P states whether the
436   expression was parsed as an id-expression or a member access
437   expression. When false, it was parsed as a full expression.
438   DECLTYPE_FOR_LAMBDA_CAPTURE is set if we want lambda capture semantics.
439   DECLTYPE_FOR_LAMBDA_RETURN is set if we want lambda return deduction.  */
440DEFTREECODE (DECLTYPE_TYPE, "decltype_type", tcc_type, 0)
441
442/* Used to represent the template information stored by template
443   specializations.
444   The accessors are:
445   TI_TEMPLATE the template declaration associated to the specialization
446   TI_ARGS the arguments of the template specialization
447   TI_TYPEDEFS_NEEDING_ACCESS_CHECKING the vector of typedefs used in
448   the pattern of the template for which access check is needed at template
449   instantiation time.  */
450DEFTREECODE (TEMPLATE_INFO, "template_info", tcc_exceptional, 0)
451
452/*
453Local variables:
454mode:c
455End:
456*/
457