1 /* This file contains the definitions and documentation for the
2 tree codes used in the GNU C compiler.
3 Copyright (C
) 1987, 1988, 1993, 1995, 1997, 1998, 2000, 2001
4 Free Software Foundation
, Inc.
6 This file is part of GCC.
8 GCC is free software
; you can redistribute it and
/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation
; either version
2, or (at your option
) any later
13 GCC is distributed in the hope that it will be useful
, but WITHOUT ANY
14 WARRANTY
; without even the implied warranty of MERCHANTABILITY or
15 FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC
; see the file COPYING. If not
, write to the Free
20 Software Foundation
, 59 Temple Place
- Suite
330, Boston
, MA
24 /* The third argument can be
:
25 'x' for an exceptional
code (fits no category
).
26 't' for a type object code.
27 'b' for a lexical block.
28 'c' for codes for constants.
29 'd' for codes for
declarations (also serving as variable refs
).
30 'r' for codes for references to storage.
31 '<' for codes for comparison expressions.
32 '1' for codes for unary arithmetic expressions.
33 '2' for codes for binary arithmetic expressions.
34 's' for codes for expressions with inherent side effects.
35 'e' for codes for other kinds of expressions.
*/
37 /* For `r
', `e', `
<', `1', `
2', `s' and `x
' nodes,
38 the 4th element is the number of argument slots to allocate.
39 This determines the size of the tree node object. */
41 /* Any erroneous construct is parsed into a node of this type.
42 This type of node is accepted without complaint in all contexts
43 by later parsing activities, to avoid multiple error messages
45 No fields in these nodes are used except the TREE_CODE. */
46 DEFTREECODE (ERROR_MARK, "error_mark", 'x
', 0)
48 /* Used to represent a name (such as, in the DECL_NAME of a decl node).
49 Internally it looks like a STRING_CST node.
50 There is only one IDENTIFIER_NODE ever made for any particular name.
51 Use `get_identifier' to get
it (or create it
, the first time
).
*/
52 DEFTREECODE (IDENTIFIER_NODE
, "identifier_node", 'x', -1)
54 /* Has the TREE_VALUE and TREE_PURPOSE fields.
*/
55 /* These nodes are made into lists by chaining through the
56 TREE_CHAIN field. The elements of the list live in the
57 TREE_VALUE fields
, while TREE_PURPOSE fields are occasionally
58 used as well to get the effect of Lisp association lists.
*/
59 DEFTREECODE (TREE_LIST
, "tree_list", 'x', 2)
61 /* These nodes contain an array of tree nodes.
*/
62 DEFTREECODE (TREE_VEC
, "tree_vec", 'x', 2)
64 /* A symbol binding block. These are arranged in a tree
,
65 where the BLOCK_SUBBLOCKS field contains a chain of subblocks
66 chained through the BLOCK_CHAIN field.
67 BLOCK_SUPERCONTEXT points to the parent block.
68 For a block which represents the outermost scope of a function
, it
69 points to the FUNCTION_DECL node.
70 BLOCK_VARS points to a chain of decl nodes.
71 BLOCK_TYPE_TAGS points to a chain of types which have their own names.
72 BLOCK_CHAIN points to the next BLOCK at the same level.
73 BLOCK_ABSTRACT_ORIGIN points to the
original (abstract
) tree node which
74 this block is an instance of
, or else is NULL to indicate that this
75 block is not an instance of anything else. When non
-NULL
, the value
76 could either point to another BLOCK node or it could point to a
77 FUNCTION_DECL
node (e.g. in the case of a block representing the
78 outermost scope of a particular inlining of a function
).
79 BLOCK_ABSTRACT is non
-zero if the block represents an abstract
80 instance of a
block (i.e. one which is nested within an abstract
81 instance of an inline function
).
82 TREE_ASM_WRITTEN is non
-zero if the block was actually referenced
83 in the generated assembly.
*/
84 DEFTREECODE (BLOCK
, "block", 'b', 0)
86 /* Each data type is represented by a tree node whose code is one of
88 /* Each node that represents a data type has a component TYPE_SIZE
89 containing a tree that is an expression for the size in bits.
90 The TYPE_MODE contains the machine mode for values of this type.
91 The TYPE_POINTER_TO field contains a type for a pointer to this type
,
92 or zero if no such has been created yet.
93 The TYPE_NEXT_VARIANT field is used to chain together types
94 that are variants made by type modifiers such as
"const" and
"volatile".
95 The TYPE_MAIN_VARIANT field
, in any member of such a chain
,
96 points to the start of the chain.
97 The TYPE_NONCOPIED_PARTS field is a list specifying which parts
98 of an object of this type should
*not
* be copied by assignment.
99 The TREE_VALUE of each is a FIELD_DECL that should not be
100 copied. The TREE_PURPOSE is an initial value for that field when
101 an object of this type is initialized via an INIT_EXPR. It may
102 be NULL if no special value is required. Even the things in this
103 list are copied if the right
-hand side of an assignment is known
104 to be a complete
object (rather than being
, perhaps
, a subobject
105 of some other object.
) The determination of what constitutes a
106 complete object is done by fixed_type_p.
107 The TYPE_NAME field contains info on the name used in the program
108 for this
type (for GDB symbol table output
). It is either a
109 TYPE_DECL node
, for types that are typedefs
, or an IDENTIFIER_NODE
110 in the case of structs
, unions or enums that are known with a tag
,
111 or zero for types that have no special name.
112 The TYPE_CONTEXT for any sort of type which could have a name or
113 which could have named
members (e.g. tagged types in C
/C
++) will
114 point to the node which represents the scope of the given type
, or
115 will be NULL_TREE if the type has
"file scope". For most types
, this
116 will point to a BLOCK node or a FUNCTION_DECL node
, but it could also
117 point to a FUNCTION_TYPE
node (for types whose scope is limited to the
118 formal parameter list of some function type specification
) or it
119 could point to a RECORD_TYPE
, UNION_TYPE or QUAL_UNION_TYPE node
120 (for C
++ "member" types
).
121 For non
-tagged
-types
, TYPE_CONTEXT need not be set to anything in
122 particular
, since any type which is of some type
category (e.g.
123 an array type or a function type
) which cannot either have a name
124 itself or have named members doesn
't really have a "scope" per se.
125 The TREE_CHAIN field is used as a forward-references to names for
126 ENUMERAL_TYPE, RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE nodes;
129 DEFTREECODE (VOID_TYPE, "void_type", 't
', 0) /* The void type in C */
131 /* Integer types in all languages, including char in C.
132 Also used for sub-ranges of other discrete types.
133 Has components TYPE_MIN_VALUE, TYPE_MAX_VALUE (expressions, inclusive)
134 and TYPE_PRECISION (number of bits used by this type).
135 In the case of a subrange type in Pascal, the TREE_TYPE
136 of this will point at the supertype (another INTEGER_TYPE,
137 or an ENUMERAL_TYPE, CHAR_TYPE, or BOOLEAN_TYPE).
138 Otherwise, the TREE_TYPE is zero. */
139 DEFTREECODE (INTEGER_TYPE, "integer_type", 't
', 0)
141 /* C's float and double. Different floating types are distinguished
142 by machine mode and by the TYPE_SIZE and the TYPE_PRECISION.
*/
143 DEFTREECODE (REAL_TYPE
, "real_type", 't', 0)
145 /* Complex number types. The TREE_TYPE field is the data type
146 of the real and imaginary parts.
*/
147 DEFTREECODE (COMPLEX_TYPE
, "complex_type", 't', 0)
149 /* Vector types. The TREE_TYPE field is the data type of the vector
151 DEFTREECODE (VECTOR_TYPE
, "vector_type", 't', 0)
153 /* C enums. The type node looks just like an INTEGER_TYPE node.
154 The symbols for the values of the enum type are defined by
155 CONST_DECL nodes
, but the type does not point to them
;
156 however
, the TYPE_VALUES is a list in which each element
's TREE_PURPOSE
157 is a name and the TREE_VALUE is the value (an INTEGER_CST node). */
158 /* A forward reference `enum foo' when no enum named foo is defined yet
159 has
zero (a null pointer
) in its TYPE_SIZE. The tag name is in
160 the TYPE_NAME field. If the type is later defined
, the normal
161 fields are filled in.
162 RECORD_TYPE
, UNION_TYPE
, and QUAL_UNION_TYPE forward refs are
163 treated similarly.
*/
164 DEFTREECODE (ENUMERAL_TYPE
, "enumeral_type", 't', 0)
166 /* Pascal
's boolean type (true or false are the only values);
167 no special fields needed. */
168 DEFTREECODE (BOOLEAN_TYPE, "boolean_type", 't
', 0)
170 /* CHAR in Pascal; not used in C.
171 No special fields needed. */
172 DEFTREECODE (CHAR_TYPE, "char_type", 't
', 0)
174 /* All pointer-to-x types have code POINTER_TYPE.
175 The TREE_TYPE points to the node for the type pointed to. */
176 DEFTREECODE (POINTER_TYPE, "pointer_type", 't
', 0)
178 /* An offset is a pointer relative to an object.
179 The TREE_TYPE field is the type of the object at the offset.
180 The TYPE_OFFSET_BASETYPE points to the node for the type of object
181 that the offset is relative to. */
182 DEFTREECODE (OFFSET_TYPE, "offset_type", 't
', 0)
184 /* A reference is like a pointer except that it is coerced
185 automatically to the value it points to. Used in C++. */
186 DEFTREECODE (REFERENCE_TYPE, "reference_type", 't
', 0)
188 /* METHOD_TYPE is the type of a function which takes an extra first
189 argument for "self", which is not present in the declared argument list.
190 The TREE_TYPE is the return type of the method. The TYPE_METHOD_BASETYPE
191 is the type of "self". TYPE_ARG_TYPES is the real argument list, which
192 includes the hidden argument for "self". */
193 DEFTREECODE (METHOD_TYPE, "method_type", 't
', 0)
195 /* Used for Pascal; details not determined right now. */
196 DEFTREECODE (FILE_TYPE, "file_type", 't
', 0)
198 /* Types of arrays. Special fields:
199 TREE_TYPE Type of an array element.
200 TYPE_DOMAIN Type to index by.
201 Its range of values specifies the array length.
202 TYPE_SEP Expression for units from one elt to the next.
203 TYPE_SEP_UNIT Number of bits in a unit for previous.
204 The field TYPE_POINTER_TO (TREE_TYPE (array_type)) is always nonzero
205 and holds the type to coerce a value of that array type to in C.
206 TYPE_STRING_FLAG indicates a string (in contrast to an array of chars)
207 in languages (such as Chill) that make a distinction. */
208 /* Array types in C or Pascal */
209 DEFTREECODE (ARRAY_TYPE, "array_type", 't
', 0)
211 /* Types of sets for Pascal. Special fields are the same as
212 in an array type. The target type is always a boolean type.
213 Used for both bitstrings and powersets in Chill;
214 TYPE_STRING_FLAG indicates a bitstring. */
215 DEFTREECODE (SET_TYPE, "set_type", 't
', 0)
217 /* Struct in C, or record in Pascal. */
219 TYPE_FIELDS chain of FIELD_DECLs for the fields of the struct,
220 and VAR_DECLs, TYPE_DECLs and CONST_DECLs for record-scope variables,
221 types and enumerators.
222 A few may need to be added for Pascal. */
223 /* See the comment above, before ENUMERAL_TYPE, for how
224 forward references to struct tags are handled in C. */
225 DEFTREECODE (RECORD_TYPE, "record_type", 't
', 0)
227 /* Union in C. Like a struct, except that the offsets of the fields
229 /* See the comment above, before ENUMERAL_TYPE, for how
230 forward references to union tags are handled in C. */
231 DEFTREECODE (UNION_TYPE, "union_type", 't
', 0) /* C union type */
233 /* Similar to UNION_TYPE, except that the expressions in DECL_QUALIFIER
234 in each FIELD_DECL determine what the union contains. The first
235 field whose DECL_QUALIFIER expression is true is deemed to occupy
237 DEFTREECODE (QUAL_UNION_TYPE, "qual_union_type", 't
', 0)
239 /* Type of functions. Special fields:
240 TREE_TYPE type of value returned.
241 TYPE_ARG_TYPES list of types of arguments expected.
242 this list is made of TREE_LIST nodes.
243 Types of "Procedures" in languages where they are different from functions
244 have code FUNCTION_TYPE also, but then TREE_TYPE is zero or void type. */
245 DEFTREECODE (FUNCTION_TYPE, "function_type", 't
', 0)
247 /* This is a language-specific kind of type.
248 Its meaning is defined by the language front end.
249 layout_type does not know how to lay this out,
250 so the front-end must do so manually. */
251 DEFTREECODE (LANG_TYPE, "lang_type", 't
', 0)
255 /* First, the constants. */
257 /* Contents are in TREE_INT_CST_LOW and TREE_INT_CST_HIGH fields,
258 32 bits each, giving us a 64 bit constant capability.
259 Note: constants of type char in Pascal are INTEGER_CST,
260 and so are pointer constants such as nil in Pascal or NULL in C.
261 `(int *) 1' in C also results in an INTEGER_CST.
*/
262 DEFTREECODE (INTEGER_CST
, "integer_cst", 'c', 2)
264 /* Contents are in TREE_REAL_CST field. Also there is TREE_CST_RTL.
*/
265 DEFTREECODE (REAL_CST
, "real_cst", 'c', 3)
267 /* Contents are in TREE_REALPART and TREE_IMAGPART fields
,
268 whose contents are other constant nodes.
269 Also there is TREE_CST_RTL.
*/
270 DEFTREECODE (COMPLEX_CST
, "complex_cst", 'c', 3)
272 /* Contents are TREE_STRING_LENGTH and TREE_STRING_POINTER fields.
273 Also there is TREE_CST_RTL.
*/
274 DEFTREECODE (STRING_CST
, "string_cst", 'c', 3)
276 /* Declarations. All references to names are represented as ..._DECL nodes.
277 The decls in one binding context are chained through the TREE_CHAIN field.
278 Each DECL has a DECL_NAME field which contains an IDENTIFIER_NODE.
279 (Some decls
, most often labels
, may have zero as the DECL_NAME
).
280 DECL_CONTEXT points to the node representing the context in which
281 this declaration has its scope. For FIELD_DECLs
, this is the
282 RECORD_TYPE
, UNION_TYPE
, or QUAL_UNION_TYPE node that the field
283 is a member of. For VAR_DECL
, PARM_DECL
, FUNCTION_DECL
, LABEL_DECL
,
284 and CONST_DECL nodes
, this points to either the FUNCTION_DECL for the
285 containing function
, the RECORD_TYPE or UNION_TYPE for the containing
286 type
, or NULL_TREE if the given decl has
"file scope".
287 DECL_ABSTRACT_ORIGIN
, if non
-NULL
, points to the
original (abstract
)
288 ..._DECL node of which this decl is
an (inlined or template expanded
)
290 The TREE_TYPE field holds the data type of the object
, when relevant.
291 LABEL_DECLs have no data type. For TYPE_DECL
, the TREE_TYPE field
292 contents are the type whose name is being declared.
293 The DECL_ALIGN
, DECL_SIZE
,
294 and DECL_MODE fields exist in decl nodes just as in type nodes.
295 They are unused in LABEL_DECL
, TYPE_DECL and CONST_DECL nodes.
297 DECL_OFFSET holds an integer number of bits offset for the location.
298 DECL_VOFFSET holds an expression for a variable offset
; it is
299 to be multiplied by
DECL_VOFFSET_UNIT (an integer
).
300 These fields are relevant only in FIELD_DECLs and PARM_DECLs.
302 DECL_INITIAL holds the value to initialize a variable to
,
303 or the value of a constant. For a function
, it holds the body
304 (a node of type BLOCK representing the function
's binding contour
305 and whose body contains the function's statements.
) For a LABEL_DECL
306 in C
, it is a flag
, nonzero if the label
's definition has been seen.
308 PARM_DECLs use a special field:
309 DECL_ARG_TYPE is the type in which the argument is actually
310 passed, which may be different from its type within the function.
312 FUNCTION_DECLs use four special fields:
313 DECL_ARGUMENTS holds a chain of PARM_DECL nodes for the arguments.
314 DECL_RESULT holds a RESULT_DECL node for the value of a function,
315 or it is 0 for a function that returns no value.
316 (C functions returning void have zero here.)
317 The TREE_TYPE field is the type in which the result is actually
318 returned. This is usually the same as the return type of the
319 FUNCTION_DECL, but it may be a wider integer type because of
321 DECL_FUNCTION_CODE is a code number that is nonzero for
322 built-in functions. Its value is an enum built_in_function
323 that says which built-in function it is.
325 DECL_SOURCE_FILE holds a filename string and DECL_SOURCE_LINE
326 holds a line number. In some cases these can be the location of
327 a reference, if no definition has been seen.
329 DECL_ABSTRACT is non-zero if the decl represents an abstract instance
330 of a decl (i.e. one which is nested within an abstract instance of a
333 DEFTREECODE (FUNCTION_DECL, "function_decl", 'd
', 0)
334 DEFTREECODE (LABEL_DECL, "label_decl", 'd
', 0)
335 DEFTREECODE (CONST_DECL, "const_decl", 'd
', 0)
336 DEFTREECODE (TYPE_DECL, "type_decl", 'd
', 0)
337 DEFTREECODE (VAR_DECL, "var_decl", 'd
', 0)
338 DEFTREECODE (PARM_DECL, "parm_decl", 'd
', 0)
339 DEFTREECODE (RESULT_DECL, "result_decl", 'd
', 0)
340 DEFTREECODE (FIELD_DECL, "field_decl", 'd
', 0)
342 /* A namespace declaration. Namespaces appear in DECL_CONTEXT of other
343 _DECLs, providing a hierarchy of names. */
344 DEFTREECODE (NAMESPACE_DECL, "namespace_decl", 'd
', 0)
346 /* References to storage. */
348 /* Value is structure or union component.
349 Operand 0 is the structure or union (an expression);
350 operand 1 is the field (a node of type FIELD_DECL). */
351 DEFTREECODE (COMPONENT_REF, "component_ref", 'r
', 2)
353 /* Reference to a group of bits within an object. Similar to COMPONENT_REF
354 except the position is given explicitly rather than via a FIELD_DECL.
355 Operand 0 is the structure or union expression;
356 operand 1 is a tree giving the number of bits being referenced;
357 operand 2 is a tree giving the position of the first referenced bit.
358 The field can be either a signed or unsigned field;
359 TREE_UNSIGNED says which. */
360 DEFTREECODE (BIT_FIELD_REF, "bit_field_ref", 'r
', 3)
362 /* C unary `*' or Pascal `^
'. One operand, an expression for a pointer. */
363 DEFTREECODE (INDIRECT_REF, "indirect_ref", 'r
', 1)
365 /* Pascal `^` on a file. One operand, an expression for the file. */
366 DEFTREECODE (BUFFER_REF, "buffer_ref", 'r
', 1)
369 Operand 0 is the array; operand 1 is a (single) array index. */
370 DEFTREECODE (ARRAY_REF, "array_ref", 'r
', 2)
372 /* Likewise, except that the result is a range ("slice") of the array. The
373 starting index of the resulting array is taken from operand 1 and the size
374 of the range is taken from the type of the expression. */
375 DEFTREECODE (ARRAY_RANGE_REF, "array_range_ref", 'r
', 2)
377 /* Vtable indexing. Carries data useful for emitting information
378 for vtable garbage collection.
379 Operand 0: an array_ref (or equivalent expression)
380 Operand 1: the vtable base (must be a var_decl)
381 Operand 2: index into vtable (must be an integer_cst). */
382 DEFTREECODE (VTABLE_REF, "vtable_ref", 'r
', 3)
384 /* Constructor: return an aggregate value made from specified components.
385 In C, this is used only for structure and array initializers.
386 Also used for SET_TYPE in Chill (and potentially Pascal).
387 The first "operand" is really a pointer to the RTL,
388 for constant constructors only.
389 The second operand is a list of component values
390 made out of a chain of TREE_LIST nodes.
393 The TREE_PURPOSE of each node is the corresponding index.
394 If the TREE_PURPOSE is a RANGE_EXPR, it is a short-hand for many nodes,
395 one for each index in the range. (If the corresponding TREE_VALUE
396 has side-effects, they are evaluated once for each element. Wrap the
397 value in a SAVE_EXPR if you want to evaluate side effects only once.)
399 For RECORD_TYPE, UNION_TYPE, or QUAL_UNION_TYPE:
400 The TREE_PURPOSE of each node is a FIELD_DECL.
403 The TREE_VALUE specifies a value (index) in the set that is true.
404 If TREE_PURPOSE is non-NULL, it specifies the lower limit of a
405 range of true values. Elements not listed are false (not in the set). */
406 DEFTREECODE (CONSTRUCTOR, "constructor", 'e
', 2)
408 /* The expression types are mostly straightforward, with the fourth argument
409 of DEFTREECODE saying how many operands there are.
410 Unless otherwise specified, the operands are expressions and the
411 types of all the operands and the expression must all be the same. */
413 /* Contains two expressions to compute, one followed by the other.
414 the first value is ignored. The second one's value is used. The
415 type of the first expression need not agree with the other types.
*/
416 DEFTREECODE (COMPOUND_EXPR
, "compound_expr", 'e', 2)
418 /* Assignment expression. Operand
0 is the what to set
; 1, the new value.
*/
419 DEFTREECODE (MODIFY_EXPR
, "modify_expr", 'e', 2)
421 /* Initialization expression. Operand
0 is the variable to initialize
;
422 Operand
1 is the initializer.
*/
423 DEFTREECODE (INIT_EXPR
, "init_expr", 'e', 2)
425 /* For TARGET_EXPR
, operand
0 is the target of an initialization
,
426 operand
1 is the initializer for the target
,
427 and operand
2 is the cleanup for this node
, if any.
428 and operand
3 is the saved initializer after this node has been
429 expanded once
, this is so we can re
-expand the tree later.
*/
430 DEFTREECODE (TARGET_EXPR
, "target_expr", 'e', 4)
432 /* Conditional
expression ( ... ? ...
: ... in C
).
433 Operand
0 is the condition.
434 Operand
1 is the then
-value.
435 Operand
2 is the else
-value.
436 Operand
0 may be of any type.
437 Operand
1 must have the same type as the entire expression
, unless
438 it unconditionally throws an exception
, in which case it should
439 have VOID_TYPE. The same constraints apply to operand
2.
*/
440 DEFTREECODE (COND_EXPR
, "cond_expr", 'e', 3)
442 /* Declare local variables
, including making RTL and allocating space.
443 Operand
0 is a chain of VAR_DECL nodes for the variables.
444 Operand
1 is the body
, the expression to be computed using
445 the variables. The value of operand
1 becomes that of the BIND_EXPR.
446 Operand
2 is the BLOCK that corresponds to these bindings
447 for debugging purposes. If this BIND_EXPR is actually expanded
,
448 that sets the TREE_USED flag in the BLOCK.
450 The BIND_EXPR is not responsible for informing parsers
451 about these variables. If the body is coming from the input file
,
452 then the code that creates the BIND_EXPR is also responsible for
453 informing the parser of the variables.
455 If the BIND_EXPR is ever expanded
, its TREE_USED flag is set.
456 This tells the code for debugging symbol tables not to ignore the BIND_EXPR.
457 If the BIND_EXPR should be output for debugging but will not be expanded
,
458 set the TREE_USED flag by hand.
460 In order for the BIND_EXPR to be known at all
, the code that creates it
461 must also install it as a subblock in the tree of BLOCK
462 nodes for the function.
*/
463 DEFTREECODE (BIND_EXPR
, "bind_expr", 'e', 3)
465 /* Function call. Operand
0 is the function.
466 Operand
1 is the argument list
, a list of expressions
467 made out of a chain of TREE_LIST nodes.
*/
468 DEFTREECODE (CALL_EXPR
, "call_expr", 'e', 2)
470 /* Call a method. Operand
0 is the method
, whose type is a METHOD_TYPE.
471 Operand
1 is the expression for
"self".
472 Operand
2 is the list of explicit arguments.
*/
473 DEFTREECODE (METHOD_CALL_EXPR
, "method_call_expr", 'e', 4)
475 /* Specify a value to compute along with its corresponding cleanup.
476 Operand
0 argument is an expression whose value needs a cleanup.
477 Operand
1 is the cleanup expression for the object.
478 Operand
2 is an RTL_EXPR which will eventually represent that value.
479 The RTL_EXPR is used in this expression
, which is how the expression
480 manages to act on the proper value.
481 The cleanup is executed by the first enclosing CLEANUP_POINT_EXPR
, if
482 it exists
, otherwise it is the responsibility of the caller to manually
483 call expand_start_target_temps
/expand_end_target_temps
, as needed.
485 This differs from TRY_CATCH_EXPR in that operand
2 is always
486 evaluated when an exception isn
't thrown when cleanups are run. */
487 DEFTREECODE (WITH_CLEANUP_EXPR, "with_cleanup_expr", 'e
', 3)
489 /* Specify a cleanup point.
490 Operand 0 is an expression that may have cleanups. If it does, those
491 cleanups are executed after the expression is expanded.
493 Note that if the expression is a reference to storage, it is forced out
494 of memory before the cleanups are run. This is necessary to handle
495 cases where the cleanups modify the storage referenced; in the
496 expression 't.i
', if 't
' is a struct with an integer member 'i
' and a
497 cleanup which modifies 'i
', the value of the expression depends on
498 whether the cleanup is run before or after 't.i
' is evaluated. When
499 expand_expr is run on 't.i
', it returns a MEM. This is not good enough;
500 the value of 't.i
' must be forced out of memory.
502 As a consequence, the operand of a CLEANUP_POINT_EXPR must not have
503 BLKmode, because it will not be forced out of memory. */
504 DEFTREECODE (CLEANUP_POINT_EXPR, "cleanup_point_expr", 'e
', 1)
506 /* The following two codes are used in languages that have types where
507 some field in an object of the type contains a value that is used in
508 the computation of another field's offset or size and
/or the size of
509 the type. The positions and
/or sizes of fields can vary from object
510 to object of the same type.
512 Record types with discriminants in Ada or schema types in Pascal are
513 examples of such types. This mechanism is also used to create
"fat
514 pointers" for unconstrained array types in Ada
; the fat pointer is a
515 structure one of whose fields is a pointer to the actual array type
516 and the other field is a pointer to a template
, which is a structure
517 containing the bounds of the array. The bounds in the type pointed
518 to by the first field in the fat pointer refer to the values in the
521 When you wish to construct such a type you need
"self-references"
522 that allow you to reference the object having this type from the
523 TYPE node
, i.e. without having a variable instantiating this type.
525 Such a
"self-references" is done using a PLACEHOLDER_EXPR. This is
526 a node that will later be replaced with the object being referenced.
527 Its type is that of the object and selects which object to use from
528 a chain of
references (see below
). No other slots are used in the
531 For example
, if your type FOO is a RECORD_TYPE with a field BAR
,
532 and you need the value of
<variable
>.BAR to calculate TYPE_SIZE
533 (FOO
), just substitute
<variable
> above with a PLACEHOLDER_EXPR
534 what contains both the expression we wish to
535 evaluate and an expression within which the object may be found.
536 The latter expression is the object itself in the simple case of an
537 Ada record with discriminant
, but it can be the array in the case of
538 an unconstrained array.
540 In the latter case
, we need the fat pointer
, because the bounds of
541 the array can only be accessed from it. However
, we rely here on the
542 fact that the expression for the array contains the dereference of
543 the fat pointer that obtained the array pointer.
545 Accordingly
, when looking for the object to substitute in place of
546 a PLACEHOLDER_EXPR
, we look down the first operand of the expression
547 passed as the second operand to WITH_RECORD_EXPR until we find
548 something of the desired type or reach a constant.
*/
550 /* Denotes a record to later be supplied with a WITH_RECORD_EXPR when
551 evaluating this expression. The type of this expression is used to
552 find the record to replace it.
*/
553 DEFTREECODE (PLACEHOLDER_EXPR
, "placeholder_expr", 'x', 0)
555 /* Provide an expression that references a record to be used in place
556 of a PLACEHOLDER_EXPR. The record to be used is the record within
557 operand
1 that has the same type as the PLACEHOLDER_EXPR in
559 DEFTREECODE (WITH_RECORD_EXPR
, "with_record_expr", 'e', 2)
561 /* Simple arithmetic.
*/
562 DEFTREECODE (PLUS_EXPR
, "plus_expr", '2', 2)
563 DEFTREECODE (MINUS_EXPR
, "minus_expr", '2', 2)
564 DEFTREECODE (MULT_EXPR
, "mult_expr", '2', 2)
566 /* Division for integer result that rounds the quotient toward zero.
*/
567 DEFTREECODE (TRUNC_DIV_EXPR
, "trunc_div_expr", '2', 2)
569 /* Division for integer result that rounds the quotient toward infinity.
*/
570 DEFTREECODE (CEIL_DIV_EXPR
, "ceil_div_expr", '2', 2)
572 /* Division for integer result that rounds toward minus infinity.
*/
573 DEFTREECODE (FLOOR_DIV_EXPR
, "floor_div_expr", '2', 2)
575 /* Division for integer result that rounds toward nearest integer.
*/
576 DEFTREECODE (ROUND_DIV_EXPR
, "round_div_expr", '2', 2)
578 /* Four kinds of remainder that go with the four kinds of division.
*/
579 DEFTREECODE (TRUNC_MOD_EXPR
, "trunc_mod_expr", '2', 2)
580 DEFTREECODE (CEIL_MOD_EXPR
, "ceil_mod_expr", '2', 2)
581 DEFTREECODE (FLOOR_MOD_EXPR
, "floor_mod_expr", '2', 2)
582 DEFTREECODE (ROUND_MOD_EXPR
, "round_mod_expr", '2', 2)
584 /* Division for real result.
*/
585 DEFTREECODE (RDIV_EXPR
, "rdiv_expr", '2', 2)
587 /* Division which is not supposed to need rounding.
588 Used for pointer subtraction in C.
*/
589 DEFTREECODE (EXACT_DIV_EXPR
, "exact_div_expr", '2', 2)
591 /* Conversion of real to fixed point
: four ways to round
,
592 like the four ways to divide.
593 CONVERT_EXPR can also be used to convert a real to an integer
,
594 and that is what is used in languages that do not have ways of
595 specifying which of these is wanted. Maybe these are not needed.
*/
596 DEFTREECODE (FIX_TRUNC_EXPR
, "fix_trunc_expr", '1', 1)
597 DEFTREECODE (FIX_CEIL_EXPR
, "fix_ceil_expr", '1', 1)
598 DEFTREECODE (FIX_FLOOR_EXPR
, "fix_floor_expr", '1', 1)
599 DEFTREECODE (FIX_ROUND_EXPR
, "fix_round_expr", '1', 1)
601 /* Conversion of an integer to a real.
*/
602 DEFTREECODE (FLOAT_EXPR
, "float_expr", '1', 1)
604 /* Unary negation.
*/
605 DEFTREECODE (NEGATE_EXPR
, "negate_expr", '1', 1)
607 DEFTREECODE (MIN_EXPR
, "min_expr", '2', 2)
608 DEFTREECODE (MAX_EXPR
, "max_expr", '2', 2)
610 /* Represents the absolute value of the operand.
612 An ABS_EXPR must have either an INTEGER_TYPE or a REAL_TYPE. The
613 operand of the ABS_EXPR must have the same type.
*/
614 DEFTREECODE (ABS_EXPR
, "abs_expr", '1', 1)
616 DEFTREECODE (FFS_EXPR
, "ffs_expr", '1', 1)
618 /* Shift operations for shift and rotate.
619 Shift means logical shift if done on an
620 unsigned type
, arithmetic shift if done on a signed type.
621 The second operand is the number of bits to
622 shift by
; it need not be the same type as the first operand and result.
623 Note that the result is undefined if the second operand is larger
624 than the first operand
's type size. */
625 DEFTREECODE (LSHIFT_EXPR, "lshift_expr", '2', 2)
626 DEFTREECODE (RSHIFT_EXPR, "rshift_expr", '2', 2)
627 DEFTREECODE (LROTATE_EXPR, "lrotate_expr", '2', 2)
628 DEFTREECODE (RROTATE_EXPR, "rrotate_expr", '2', 2)
630 /* Bitwise operations. Operands have same mode as result. */
631 DEFTREECODE (BIT_IOR_EXPR, "bit_ior_expr", '2', 2)
632 DEFTREECODE (BIT_XOR_EXPR, "bit_xor_expr", '2', 2)
633 DEFTREECODE (BIT_AND_EXPR, "bit_and_expr", '2', 2)
634 DEFTREECODE (BIT_ANDTC_EXPR, "bit_andtc_expr", '2', 2)
635 DEFTREECODE (BIT_NOT_EXPR, "bit_not_expr", '1', 1)
637 /* ANDIF and ORIF allow the second operand not to be computed if the
638 value of the expression is determined from the first operand. AND,
639 OR, and XOR always compute the second operand whether its value is
640 needed or not (for side effects). The operand may have
641 BOOLEAN_TYPE or INTEGER_TYPE. In either case, the argument will be
642 either zero or one. For example, a TRUTH_NOT_EXPR will never have
643 a INTEGER_TYPE VAR_DECL as its argument; instead, a NE_EXPR will be
644 used to compare the VAR_DECL to zero, thereby obtaining a node with
645 value zero or one. */
646 DEFTREECODE (TRUTH_ANDIF_EXPR, "truth_andif_expr", 'e
', 2)
647 DEFTREECODE (TRUTH_ORIF_EXPR, "truth_orif_expr", 'e
', 2)
648 DEFTREECODE (TRUTH_AND_EXPR, "truth_and_expr", 'e
', 2)
649 DEFTREECODE (TRUTH_OR_EXPR, "truth_or_expr", 'e
', 2)
650 DEFTREECODE (TRUTH_XOR_EXPR, "truth_xor_expr", 'e
', 2)
651 DEFTREECODE (TRUTH_NOT_EXPR, "truth_not_expr", 'e
', 1)
653 /* Relational operators.
654 `EQ_EXPR' and `NE_EXPR
' are allowed for any types.
655 The others are allowed only for integer (or pointer or enumeral)
657 In all cases the operands will have the same type,
658 and the value is always the type used by the language for booleans. */
659 DEFTREECODE (LT_EXPR, "lt_expr", '<', 2)
660 DEFTREECODE (LE_EXPR, "le_expr", '<', 2)
661 DEFTREECODE (GT_EXPR, "gt_expr", '<', 2)
662 DEFTREECODE (GE_EXPR, "ge_expr", '<', 2)
663 DEFTREECODE (EQ_EXPR, "eq_expr", '<', 2)
664 DEFTREECODE (NE_EXPR, "ne_expr", '<', 2)
666 /* Additional relational operators for floating point unordered. */
667 DEFTREECODE (UNORDERED_EXPR, "unordered_expr", '<', 2)
668 DEFTREECODE (ORDERED_EXPR, "ordered_expr", '<', 2)
670 /* These are equivalent to unordered or ... */
671 DEFTREECODE (UNLT_EXPR, "unlt_expr", '<', 2)
672 DEFTREECODE (UNLE_EXPR, "unle_expr", '<', 2)
673 DEFTREECODE (UNGT_EXPR, "ungt_expr", '<', 2)
674 DEFTREECODE (UNGE_EXPR, "unge_expr", '<', 2)
675 DEFTREECODE (UNEQ_EXPR, "uneq_expr", '<', 2)
677 /* Operations for Pascal sets. Not used now. */
678 DEFTREECODE (IN_EXPR, "in_expr", '2', 2)
679 DEFTREECODE (SET_LE_EXPR, "set_le_expr", '<', 2)
680 DEFTREECODE (CARD_EXPR, "card_expr", '1', 1)
681 DEFTREECODE (RANGE_EXPR, "range_expr", '2', 2)
683 /* Represents a conversion of type of a value.
684 All conversions, including implicit ones, must be
685 represented by CONVERT_EXPR or NOP_EXPR nodes. */
686 DEFTREECODE (CONVERT_EXPR, "convert_expr", '1', 1)
688 /* Represents a conversion expected to require no code to be generated. */
689 DEFTREECODE (NOP_EXPR, "nop_expr", '1', 1)
691 /* Value is same as argument, but guaranteed not an lvalue. */
692 DEFTREECODE (NON_LVALUE_EXPR, "non_lvalue_expr", '1', 1)
694 /* Represents viewing something of one type as being of a second type.
695 This corresponds to an "Unchecked Conversion" in Ada and roughly to
696 the idiom *(type2 *)&X in C. The only operand is the value to be
697 viewed as being of another type. It is undefined if the type of the
698 input and of the expression have different sizes. */
699 DEFTREECODE (VIEW_CONVERT_EXPR, "view_convert_expr", '1', 1)
701 /* Represents something we computed once and will use multiple times.
702 First operand is that expression. Second is the function decl
703 in which the SAVE_EXPR was created. The third operand is the RTL,
704 nonzero only after the expression has been computed. */
705 DEFTREECODE (SAVE_EXPR, "save_expr", 'e
', 3)
707 /* For a UNSAVE_EXPR, operand 0 is the value to unsave. By unsave, we
708 mean that all _EXPRs such as TARGET_EXPRs, SAVE_EXPRs,
709 CALL_EXPRs and RTL_EXPRs, that are protected
710 from being evaluated more than once should be reset so that a new
711 expand_expr call of this expr will cause those to be re-evaluated.
712 This is useful when we want to reuse a tree in different places,
713 but where we must re-expand. */
714 DEFTREECODE (UNSAVE_EXPR, "unsave_expr", 'e
', 1)
716 /* Represents something whose RTL has already been expanded as a
717 sequence which should be emitted when this expression is expanded.
718 The first operand is the RTL to emit. It is the first of a chain
719 of insns. The second is the RTL expression for the result. Any
720 temporaries created during the building of the RTL_EXPR can be
721 reused once the RTL_EXPR has been expanded, with the exception of
723 DEFTREECODE (RTL_EXPR, "rtl_expr", 'e
', 2)
725 /* & in C. Value is the address at which the operand's value resides.
726 Operand may have any mode. Result mode is Pmode.
*/
727 DEFTREECODE (ADDR_EXPR
, "addr_expr", 'e', 1)
729 /* Non
-lvalue reference or pointer to an object.
*/
730 DEFTREECODE (REFERENCE_EXPR
, "reference_expr", 'e', 1)
732 /* Operand is a function constant
; result is a function variable value
733 of type EPmode. Used only for languages that need static chains.
*/
734 DEFTREECODE (ENTRY_VALUE_EXPR
, "entry_value_expr", 'e', 1)
736 /* Operand0 is a function constant
; result is part N of a function
737 descriptor of type ptr_mode.
*/
738 DEFTREECODE (FDESC_EXPR
, "fdesc_expr", 'e', 2)
740 /* Given two real or integer operands of the same type
,
741 returns a complex value of the corresponding complex type.
*/
742 DEFTREECODE (COMPLEX_EXPR
, "complex_expr", '2', 2)
744 /* Complex conjugate of operand. Used only on complex types.
*/
745 DEFTREECODE (CONJ_EXPR
, "conj_expr", '1', 1)
747 /* Used only on an operand of complex type
, these return
748 a value of the corresponding component type.
*/
749 DEFTREECODE (REALPART_EXPR
, "realpart_expr", '1', 1)
750 DEFTREECODE (IMAGPART_EXPR
, "imagpart_expr", '1', 1)
752 /* Nodes for
++ and
-- in C.
753 The second arg is how much to increment or decrement by.
754 For a pointer
, it would be the size of the object pointed to.
*/
755 DEFTREECODE (PREDECREMENT_EXPR
, "predecrement_expr", 'e', 2)
756 DEFTREECODE (PREINCREMENT_EXPR
, "preincrement_expr", 'e', 2)
757 DEFTREECODE (POSTDECREMENT_EXPR
, "postdecrement_expr", 'e', 2)
758 DEFTREECODE (POSTINCREMENT_EXPR
, "postincrement_expr", 'e', 2)
760 /* Used to implement `va_arg
'. */
761 DEFTREECODE (VA_ARG_EXPR, "va_arg_expr", 'e
', 1)
763 /* Evaluate operand 1. If and only if an exception is thrown during
764 the evaluation of operand 1, evaluate operand 2.
766 This differs from WITH_CLEANUP_EXPR, in that operand 2 is never
767 evaluated unless an exception is throw. */
768 DEFTREECODE (TRY_CATCH_EXPR, "try_catch_expr", 'e
', 2)
770 /* Evaluate the first operand.
771 The second operand is a a cleanup expression which is evaluated
772 before an exit (normal, exception, or jump out) from this expression.
774 Like a CLEANUP_POINT_EXPR/WITH_CLEANUP_EXPR combination, but those
775 always copy the cleanup expression where needed. In contrast,
776 TRY_FINALLY_EXPR generates a jump to a cleanup subroutine.
777 (At least conceptually; the optimizer could inline the cleanup
778 subroutine in the same way it could inline normal subroutines.)
779 TRY_FINALLY_EXPR should be used when the cleanup is actual statements
780 in the source of the current function (which people might want to
781 set breakpoints in). */
782 DEFTREECODE (TRY_FINALLY_EXPR, "try_finally", 'e
', 2)
784 /* Used internally for cleanups in the implementation of TRY_FINALLY_EXPR.
785 (Specifically, it is created by expand_expr, not front-ends.)
786 Operand 0 is the rtx for the start of the subroutine we need to call.
787 Operand 1 is the rtx for a variable in which to store the address
788 of where the subroutine should return to. */
789 DEFTREECODE (GOTO_SUBROUTINE_EXPR, "goto_subroutine", 'e
', 2)
791 /* These types of expressions have no useful value,
792 and always have side effects. */
794 /* A label definition, encapsulated as a statement.
795 Operand 0 is the LABEL_DECL node for the label that appears here.
796 The type should be void and the value should be ignored. */
797 DEFTREECODE (LABEL_EXPR, "label_expr", 's
', 1)
799 /* GOTO. Operand 0 is a LABEL_DECL node or an expression.
800 The type should be void and the value should be ignored. */
801 DEFTREECODE (GOTO_EXPR, "goto_expr", 's
', 1)
803 /* RETURN. Evaluates operand 0, then returns from the current function.
804 Presumably that operand is an assignment that stores into the
805 RESULT_DECL that hold the value to be returned.
806 The operand may be null.
807 The type should be void and the value should be ignored. */
808 DEFTREECODE (RETURN_EXPR, "return_expr", 's
', 1)
810 /* Exit the inner most loop conditionally. Operand 0 is the condition.
811 The type should be void and the value should be ignored. */
812 DEFTREECODE (EXIT_EXPR, "exit_expr", 's
', 1)
814 /* A loop. Operand 0 is the body of the loop.
815 It must contain an EXIT_EXPR or is an infinite loop.
816 The type should be void and the value should be ignored. */
817 DEFTREECODE (LOOP_EXPR, "loop_expr", 's
', 1)
819 /* A labeled block. Operand 0 is the label that will be generated to
820 mark the end of the block.
821 Operand 1 is the labeled block body. */
822 DEFTREECODE (LABELED_BLOCK_EXPR, "labeled_block_expr", 'e
', 2)
824 /* Exit a labeled block, possibly returning a value. Operand 0 is a
825 LABELED_BLOCK_EXPR to exit. Operand 1 is the value to return. It
827 DEFTREECODE (EXIT_BLOCK_EXPR, "exit_block_expr", 'e
', 2)
829 /* Annotates a tree node (usually an expression) with source location
830 information: a file name (EXPR_WFL_FILENAME); a line number
831 (EXPR_WFL_LINENO); and column number (EXPR_WFL_COLNO). It is
832 expanded as the contained node (EXPR_WFL_NODE); a line note should
833 be emitted first if EXPR_WFL_EMIT_LINE_NOTE.
834 The third operand is only used in the Java front-end, and will
835 eventually be removed. */
836 DEFTREECODE (EXPR_WITH_FILE_LOCATION, "expr_with_file_location", 'e
', 3)
838 /* Switch expression.
839 Operand 0 is the expression used to perform the branch,
840 Operand 1 contains the case values. The way they're organized is
841 front
-end implementation defined.
*/
842 DEFTREECODE (SWITCH_EXPR
, "switch_expr", 'e', 2)
844 /* The exception object from the runtime.
*/
845 DEFTREECODE (EXC_PTR_EXPR
, "exc_ptr_expr", 'e', 0)