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 Free Software Foundation, Inc.
5 This file is part of GNU CC.
7 GNU CC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GNU CC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GNU CC; see the file COPYING. If not, write to
19 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
22 /* The third argument can be:
23 "x" for an exceptional code (fits no category).
24 "t" for a type object code.
25 "b" for a lexical block.
26 "c" for codes for constants.
27 "d" for codes for declarations (also serving as variable refs).
28 "r" for codes for references to storage.
29 "<" for codes for comparison expressions.
30 "1" for codes for unary arithmetic expressions.
31 "2" for codes for binary arithmetic expressions.
32 "s" for codes for expressions with inherent side effects.
33 "e" for codes for other kinds of expressions. */
35 /* For `r', `e', `<', `1', `2', `s' and `x' nodes,
36 the 4th element is the number of argument slots to allocate.
37 This determines the size of the tree node object. */
39 /* Any erroneous construct is parsed into a node of this type.
40 This type of node is accepted without complaint in all contexts
41 by later parsing activities, to avoid multiple error messages
43 No fields in these nodes are used except the TREE_CODE. */
44 DEFTREECODE (ERROR_MARK, "error_mark", "x", 0)
46 /* Used to represent a name (such as, in the DECL_NAME of a decl node).
47 Internally it looks like a STRING_CST node.
48 There is only one IDENTIFIER_NODE ever made for any particular name.
49 Use `get_identifier' to get it (or create it, the first time). */
50 DEFTREECODE (IDENTIFIER_NODE, "identifier_node", "x", -1)
52 /* Used to hold information to identify an operator (or combination
53 of two operators) considered as a `noun' rather than a `verb'.
54 The first operand is encoded in the TREE_TYPE field. */
55 DEFTREECODE (OP_IDENTIFIER, "op_identifier", "x", 2)
57 /* Has the TREE_VALUE and TREE_PURPOSE fields. */
58 /* These nodes are made into lists by chaining through the
59 TREE_CHAIN field. The elements of the list live in the
60 TREE_VALUE fields, while TREE_PURPOSE fields are occasionally
61 used as well to get the effect of Lisp association lists. */
62 DEFTREECODE (TREE_LIST, "tree_list", "x", 2)
64 /* These nodes contain an array of tree nodes. */
65 DEFTREECODE (TREE_VEC, "tree_vec", "x", 2)
67 /* A symbol binding block. These are arranged in a tree,
68 where the BLOCK_SUBBLOCKS field contains a chain of subblocks
69 chained through the BLOCK_CHAIN field.
70 BLOCK_SUPERCONTEXT points to the parent block.
71 For a block which represents the outermost scope of a function, it
72 points to the FUNCTION_DECL node.
73 BLOCK_VARS points to a chain of decl nodes.
74 BLOCK_TYPE_TAGS points to a chain of types which have their own names.
75 BLOCK_CHAIN points to the next BLOCK at the same level.
76 BLOCK_ABSTRACT_ORIGIN points to the original (abstract) tree node which
77 this block is an instance of, or else is NULL to indicate that this
78 block is not an instance of anything else. When non-NULL, the value
79 could either point to another BLOCK node or it could point to a
80 FUNCTION_DECL node (e.g. in the case of a block representing the
81 outermost scope of a particular inlining of a function).
82 BLOCK_ABSTRACT is non-zero if the block represents an abstract
83 instance of a block (i.e. one which is nested within an abstract
84 instance of a inline function. */
85 DEFTREECODE (BLOCK, "block", "b", 0)
87 /* Each data type is represented by a tree node whose code is one of
89 /* Each node that represents a data type has a component TYPE_SIZE
90 containing a tree that is an expression for the size in bits.
91 The TYPE_MODE contains the machine mode for values of this type.
92 The TYPE_POINTER_TO field contains a type for a pointer to this type,
93 or zero if no such has been created yet.
94 The TYPE_NEXT_VARIANT field is used to chain together types
95 that are variants made by type modifiers such as "const" and "volatile".
96 The TYPE_MAIN_VARIANT field, in any member of such a chain,
97 points to the start of the chain.
98 The TYPE_NONCOPIED_PARTS field is a list specifying which parts
99 of an object of this type should *not* be copied by assignment.
100 The TREE_PURPOSE of each element is the offset of the part
101 and the TREE_VALUE is the size in bits of the part.
102 The TYPE_NAME field contains info on the name used in the program
103 for this type (for GDB symbol table output). It is either a
104 TYPE_DECL node, for types that are typedefs, or an IDENTIFIER_NODE
105 in the case of structs, unions or enums that are known with a tag,
106 or zero for types that have no special name.
107 The TYPE_CONTEXT for any sort of type which could have a name or
108 which could have named members (e.g. tagged types in C/C++) will
109 point to the node which represents the scope of the given type, or
110 will be NULL_TREE if the type has "file scope". For most types, this
111 will point to a BLOCK node or a FUNCTION_DECL node, but it could also
112 point to a FUNCTION_TYPE node (for types whose scope is limited to the
113 formal parameter list of some function type specification) or it
114 could point to a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE node
115 (for C++ "member" types).
116 For non-tagged-types, TYPE_CONTEXT need not be set to anything in
117 particular, since any type which is of some type category (e.g.
118 an array type or a function type) which cannot either have a name
119 itself or have named members doesn't really have a "scope" per se.
120 The TREE_CHAIN field is used as a forward-references to names for
121 ENUMERAL_TYPE, RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE nodes;
124 DEFTREECODE (VOID_TYPE, "void_type", "t", 0) /* The void type in C */
126 /* Integer types in all languages, including char in C.
127 Also used for sub-ranges of other discrete types.
128 Has components TYPE_MIN_VALUE, TYPE_MAX_VALUE (expressions, inclusive)
129 and TYPE_PRECISION (number of bits used by this type).
130 In the case of a subrange type in Pascal, the TREE_TYPE
131 of this will point at the supertype (another INTEGER_TYPE,
132 or an ENUMERAL_TYPE, CHAR_TYPE, or BOOLEAN_TYPE).
133 Otherwise, the TREE_TYPE is zero. */
134 DEFTREECODE (INTEGER_TYPE, "integer_type", "t", 0)
136 /* C's float and double. Different floating types are distinguished
137 by machine mode and by the TYPE_SIZE and the TYPE_PRECISION. */
138 DEFTREECODE (REAL_TYPE, "real_type", "t", 0)
140 /* Complex number types. The TREE_TYPE field is the data type
141 of the real and imaginary parts. */
142 DEFTREECODE (COMPLEX_TYPE, "complex_type", "t", 0)
144 /* C enums. The type node looks just like an INTEGER_TYPE node.
145 The symbols for the values of the enum type are defined by
146 CONST_DECL nodes, but the type does not point to them;
147 however, the TYPE_VALUES is a list in which each element's TREE_PURPOSE
148 is a name and the TREE_VALUE is the value (an INTEGER_CST node). */
149 /* A forward reference `enum foo' when no enum named foo is defined yet
150 has zero (a null pointer) in its TYPE_SIZE. The tag name is in
151 the TYPE_NAME field. If the type is later defined, the normal
152 fields are filled in.
153 RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE forward refs are
154 treated similarly. */
155 DEFTREECODE (ENUMERAL_TYPE, "enumeral_type", "t", 0)
157 /* Pascal's boolean type (true or false are the only values);
158 no special fields needed. */
159 DEFTREECODE (BOOLEAN_TYPE, "boolean_type", "t", 0)
161 /* CHAR in Pascal; not used in C.
162 No special fields needed. */
163 DEFTREECODE (CHAR_TYPE, "char_type", "t", 0)
165 /* All pointer-to-x types have code POINTER_TYPE.
166 The TREE_TYPE points to the node for the type pointed to. */
167 DEFTREECODE (POINTER_TYPE, "pointer_type", "t", 0)
169 /* An offset is a pointer relative to an object.
170 The TREE_TYPE field is the type of the object at the offset.
171 The TYPE_OFFSET_BASETYPE points to the node for the type of object
172 that the offset is relative to. */
173 DEFTREECODE (OFFSET_TYPE, "offset_type", "t", 0)
175 /* A reference is like a pointer except that it is coerced
176 automatically to the value it points to. Used in C++. */
177 DEFTREECODE (REFERENCE_TYPE, "reference_type", "t", 0)
179 /* METHOD_TYPE is the type of a function which takes an extra first
180 argument for "self", which is not present in the declared argument list.
181 The TREE_TYPE is the return type of the method. The TYPE_METHOD_BASETYPE
182 is the type of "self". TYPE_ARG_TYPES is the real argument list, which
183 includes the hidden argument for "self". */
184 DEFTREECODE (METHOD_TYPE, "method_type", "t", 0)
186 /* Used for Pascal; details not determined right now. */
187 DEFTREECODE (FILE_TYPE, "file_type", "t", 0)
189 /* Types of arrays. Special fields:
190 TREE_TYPE Type of an array element.
191 TYPE_DOMAIN Type to index by.
192 Its range of values specifies the array length.
193 TYPE_SEP Expression for units from one elt to the next.
194 TYPE_SEP_UNIT Number of bits in a unit for previous.
195 The field TYPE_POINTER_TO (TREE_TYPE (array_type)) is always nonzero
196 and holds the type to coerce a value of that array type to in C.
197 TYPE_STRING_FLAG indicates a string (in contrast to an array of chars)
198 in languages (such as Chill) that make a distinction. */
199 /* Array types in C or Pascal */
200 DEFTREECODE (ARRAY_TYPE, "array_type", "t", 0)
202 /* Types of sets for Pascal. Special fields are the same as
203 in an array type. The target type is always a boolean type.
204 Used for both bitstrings and powersets in Chill;
205 TYPE_STRING_FLAG indicates a bitstring. */
206 DEFTREECODE (SET_TYPE, "set_type", "t", 0)
208 /* Struct in C, or record in Pascal. */
210 TYPE_FIELDS chain of FIELD_DECLs for the fields of the struct.
211 A few may need to be added for Pascal. */
212 /* See the comment above, before ENUMERAL_TYPE, for how
213 forward references to struct tags are handled in C. */
214 DEFTREECODE (RECORD_TYPE, "record_type", "t", 0)
216 /* Union in C. Like a struct, except that the offsets of the fields
218 /* See the comment above, before ENUMERAL_TYPE, for how
219 forward references to union tags are handled in C. */
220 DEFTREECODE (UNION_TYPE, "union_type", "t", 0) /* C union type */
222 /* Similar to UNION_TYPE, except that the expressions in DECL_QUALIFIER
223 in each FIELD_DECL determine what the union contains. The first
224 field whose DECL_QUALIFIER expression is true is deemed to occupy
226 DEFTREECODE (QUAL_UNION_TYPE, "qual_union_type", "t", 0)
228 /* Type of functions. Special fields:
229 TREE_TYPE type of value returned.
230 TYPE_ARG_TYPES list of types of arguments expected.
231 this list is made of TREE_LIST nodes.
232 Types of "Procedures" in languages where they are different from functions
233 have code FUNCTION_TYPE also, but then TREE_TYPE is zero or void type. */
234 DEFTREECODE (FUNCTION_TYPE, "function_type", "t", 0)
236 /* This is a language-specific kind of type.
237 Its meaning is defined by the language front end.
238 layout_type does not know how to lay this out,
239 so the front-end must do so manually. */
240 DEFTREECODE (LANG_TYPE, "lang_type", "t", 0)
244 /* First, the constants. */
246 /* Contents are in TREE_INT_CST_LOW and TREE_INT_CST_HIGH fields,
247 32 bits each, giving us a 64 bit constant capability.
248 Note: constants of type char in Pascal are INTEGER_CST,
249 and so are pointer constants such as nil in Pascal or NULL in C.
250 `(int *) 1' in C also results in an INTEGER_CST. */
251 DEFTREECODE (INTEGER_CST, "integer_cst", "c", 2)
253 /* Contents are in TREE_REAL_CST field. Also there is TREE_CST_RTL. */
254 DEFTREECODE (REAL_CST, "real_cst", "c", 3)
256 /* Contents are in TREE_REALPART and TREE_IMAGPART fields,
257 whose contents are other constant nodes.
258 Also there is TREE_CST_RTL. */
259 DEFTREECODE (COMPLEX_CST, "complex_cst", "c", 3)
261 /* Contents are TREE_STRING_LENGTH and TREE_STRING_POINTER fields.
262 Also there is TREE_CST_RTL. */
263 DEFTREECODE (STRING_CST, "string_cst", "c", 3)
265 /* Declarations. All references to names are represented as ..._DECL nodes.
266 The decls in one binding context are chained through the TREE_CHAIN field.
267 Each DECL has a DECL_NAME field which contains an IDENTIFIER_NODE.
268 (Some decls, most often labels, may have zero as the DECL_NAME).
269 DECL_CONTEXT points to the node representing the context in which
270 this declaration has its scope. For FIELD_DECLs, this is the
271 RECORD_TYPE, UNION_TYPE, or QUAL_UNION_TYPE node that the field
272 is a member of. For VAR_DECL, PARM_DECL, FUNCTION_DECL, LABEL_DECL,
273 and CONST_DECL nodes, this points to the FUNCTION_DECL for the
274 containing function, or else yields NULL_TREE if the given decl
276 DECL_ABSTRACT_ORIGIN, if non-NULL, points to the original (abstract)
277 ..._DECL node of which this decl is an (inlined or template expanded)
279 The TREE_TYPE field holds the data type of the object, when relevant.
280 LABEL_DECLs have no data type. For TYPE_DECL, the TREE_TYPE field
281 contents are the type whose name is being declared.
282 The DECL_ALIGN, DECL_SIZE,
283 and DECL_MODE fields exist in decl nodes just as in type nodes.
284 They are unused in LABEL_DECL, TYPE_DECL and CONST_DECL nodes.
286 DECL_OFFSET holds an integer number of bits offset for the location.
287 DECL_VOFFSET holds an expression for a variable offset; it is
288 to be multiplied by DECL_VOFFSET_UNIT (an integer).
289 These fields are relevant only in FIELD_DECLs and PARM_DECLs.
291 DECL_INITIAL holds the value to initialize a variable to,
292 or the value of a constant. For a function, it holds the body
293 (a node of type BLOCK representing the function's binding contour
294 and whose body contains the function's statements.) For a LABEL_DECL
295 in C, it is a flag, nonzero if the label's definition has been seen.
297 PARM_DECLs use a special field:
298 DECL_ARG_TYPE is the type in which the argument is actually
299 passed, which may be different from its type within the function.
301 FUNCTION_DECLs use four special fields:
302 DECL_ARGUMENTS holds a chain of PARM_DECL nodes for the arguments.
303 DECL_RESULT holds a RESULT_DECL node for the value of a function,
304 or it is 0 for a function that returns no value.
305 (C functions returning void have zero here.)
306 DECL_RESULT_TYPE holds the type in which the result is actually
307 returned. This is usually the same as the type of DECL_RESULT,
308 but (1) it may be a wider integer type and
309 (2) it remains valid, for the sake of inlining, even after the
310 function's compilation is done.
311 DECL_FUNCTION_CODE is a code number that is nonzero for
312 built-in functions. Its value is an enum built_in_function
313 that says which built-in function it is.
315 DECL_SOURCE_FILE holds a filename string and DECL_SOURCE_LINE
316 holds a line number. In some cases these can be the location of
317 a reference, if no definition has been seen.
319 DECL_ABSTRACT is non-zero if the decl represents an abstract instance
320 of a decl (i.e. one which is nested within an abstract instance of a
323 DEFTREECODE (FUNCTION_DECL, "function_decl", "d", 0)
324 DEFTREECODE (LABEL_DECL, "label_decl", "d", 0)
325 DEFTREECODE (CONST_DECL, "const_decl", "d", 0)
326 DEFTREECODE (TYPE_DECL, "type_decl", "d", 0)
327 DEFTREECODE (VAR_DECL, "var_decl", "d", 0)
328 DEFTREECODE (PARM_DECL, "parm_decl", "d", 0)
329 DEFTREECODE (RESULT_DECL, "result_decl", "d", 0)
330 DEFTREECODE (FIELD_DECL, "field_decl", "d", 0)
332 /* References to storage. */
334 /* Value is structure or union component.
335 Operand 0 is the structure or union (an expression);
336 operand 1 is the field (a node of type FIELD_DECL). */
337 DEFTREECODE (COMPONENT_REF, "component_ref", "r", 2)
339 /* Reference to a group of bits within an object. Similar to COMPONENT_REF
340 except the position is given explicitly rather than via a FIELD_DECL.
341 Operand 0 is the structure or union expression;
342 operand 1 is a tree giving the number of bits being referenced;
343 operand 2 is a tree giving the position of the first referenced bit.
344 The field can be either a signed or unsigned field;
345 TREE_UNSIGNED says which. */
346 DEFTREECODE (BIT_FIELD_REF, "bit_field_ref", "r", 3)
348 /* C unary `*' or Pascal `^'. One operand, an expression for a pointer. */
349 DEFTREECODE (INDIRECT_REF, "indirect_ref", "r", 1)
351 /* Reference to the contents of an offset
352 (a value whose type is an OFFSET_TYPE).
353 Operand 0 is the object within which the offset is taken.
354 Operand 1 is the offset. */
355 DEFTREECODE (OFFSET_REF, "offset_ref", "r", 2)
357 /* Pascal `^` on a file. One operand, an expression for the file. */
358 DEFTREECODE (BUFFER_REF, "buffer_ref", "r", 1)
360 /* Array indexing in languages other than C.
361 Operand 0 is the array; operand 1 is a list of indices
362 stored as a chain of TREE_LIST nodes. */
363 DEFTREECODE (ARRAY_REF, "array_ref", "r", 2)
365 /* Constructor: return an aggregate value made from specified components.
366 In C, this is used only for structure and array initializers.
367 The first "operand" is really a pointer to the RTL,
368 for constant constructors only.
369 The second operand is a list of component values
370 made out of a chain of TREE_LIST nodes. */
371 DEFTREECODE (CONSTRUCTOR, "constructor", "e", 2)
373 /* The expression types are mostly straightforward,
374 with the fourth argument of DEFTREECODE saying
375 how many operands there are.
376 Unless otherwise specified, the operands are expressions. */
378 /* Contains two expressions to compute, one followed by the other.
379 the first value is ignored. The second one's value is used. */
380 DEFTREECODE (COMPOUND_EXPR, "compound_expr", "e", 2)
382 /* Assignment expression. Operand 0 is the what to set; 1, the new value. */
383 DEFTREECODE (MODIFY_EXPR, "modify_expr", "e", 2)
385 /* Initialization expression. Operand 0 is the variable to initialize;
386 Operand 1 is the initializer. */
387 DEFTREECODE (INIT_EXPR, "init_expr", "e", 2)
389 /* For TARGET_EXPR, operand 0 is the target of an initialization,
390 operand 1 is the initializer for the target,
391 and operand 2 is the cleanup for this node, if any. */
392 DEFTREECODE (TARGET_EXPR, "target_expr", "e", 3)
394 /* Conditional expression ( ... ? ... : ... in C).
395 Operand 0 is the condition.
396 Operand 1 is the then-value.
397 Operand 2 is the else-value. */
398 DEFTREECODE (COND_EXPR, "cond_expr", "e", 3)
400 /* Declare local variables, including making RTL and allocating space.
401 Operand 0 is a chain of VAR_DECL nodes for the variables.
402 Operand 1 is the body, the expression to be computed using
403 the variables. The value of operand 1 becomes that of the BIND_EXPR.
404 Operand 2 is the BLOCK that corresponds to these bindings
405 for debugging purposes. If this BIND_EXPR is actually expanded,
406 that sets the TREE_USED flag in the BLOCK.
408 The BIND_EXPR is not responsible for informing parsers
409 about these variables. If the body is coming from the input file,
410 then the code that creates the BIND_EXPR is also responsible for
411 informing the parser of the variables.
413 If the BIND_EXPR is ever expanded, its TREE_USED flag is set.
414 This tells the code for debugging symbol tables not to ignore the BIND_EXPR.
415 If the BIND_EXPR should be output for debugging but will not be expanded,
416 set the TREE_USED flag by hand.
418 In order for the BIND_EXPR to be known at all, the code that creates it
419 must also install it as a subblock in the tree of BLOCK
420 nodes for the function. */
421 DEFTREECODE (BIND_EXPR, "bind_expr", "e", 3)
423 /* Function call. Operand 0 is the function.
424 Operand 1 is the argument list, a list of expressions
425 made out of a chain of TREE_LIST nodes.
426 There is no operand 2. That slot is used for the
427 CALL_EXPR_RTL macro (see preexpand_calls). */
428 DEFTREECODE (CALL_EXPR, "call_expr", "e", 3)
430 /* Call a method. Operand 0 is the method, whose type is a METHOD_TYPE.
431 Operand 1 is the expression for "self".
432 Operand 2 is the list of explicit arguments. */
433 DEFTREECODE (METHOD_CALL_EXPR, "method_call_expr", "e", 4)
435 /* Specify a value to compute along with its corresponding cleanup.
436 Operand 0 argument is an expression whose value needs a cleanup.
437 Operand 1 is an RTL_EXPR which will eventually represent that value.
438 Operand 2 is the cleanup expression for the object.
439 The RTL_EXPR is used in this expression, which is how the expression
440 manages to act on the proper value.
441 The cleanup is executed by the first enclosing CLEANUP_POINT_EXPR, if
442 it exists, otherwise it is the responsibility of the caller to manually
443 call expand_cleanups_to, as needed. */
444 DEFTREECODE (WITH_CLEANUP_EXPR, "with_cleanup_expr", "e", 3)
446 /* Specify a cleanup point.
447 Operand 0 is an expression that may have cleanups. If it does, those
448 cleanups are executed after the expression is expanded.
450 Note that if the expression is a reference to storage, it is forced out
451 of memory before the cleanups are run. This is necessary to handle
452 cases where the cleanups modify the storage referenced; in the
453 expression 't.i', if 't' is a struct with an integer member 'i' and a
454 cleanup which modifies 'i', the value of the expression depends on
455 whether the cleanup is run before or after 't.i' is evaluated. When
456 expand_expr is run on 't.i', it returns a MEM. This is not good enough;
457 the value of 't.i' must be forced out of memory.
459 As a consequence, the operand of a CLEANUP_POINT_EXPR must not have
460 BLKmode, because it will not be forced out of memory. */
461 DEFTREECODE (CLEANUP_POINT_EXPR, "cleanup_point_expr", "e", 1)
463 /* The following two codes are used in languages that have types where
464 the position and/or sizes of fields vary from object to object of the
465 same type, i.e., where some other field in the object contains a value
466 that is used in the computation of another field's offset or size.
468 For example, a record type with a discriminant in Ada is such a type.
469 This mechanism is also used to create "fat pointers" for unconstrained
470 array types in Ada; the fat pointer is a structure one of whose fields is
471 a pointer to the actual array type and the other field is a pointer to a
472 template, which is a structure containing the bounds of the array. The
473 bounds in the type pointed to by the first field in the fat pointer refer
474 to the values in the template.
476 These "self-references" are doing using a PLACEHOLDER_EXPR. This is a
477 node that will later be replaced with the object being referenced. Its type
478 is that of the object and selects which object to use from a chain of
479 references (see below).
481 When we wish to evaluate a size or offset, we check it is contains a
482 placeholder. If it does, we construct a WITH_RECORD_EXPR that contains
483 both the expression we wish to evaluate and an expression within which the
484 object may be found. The latter expression is the object itself in
485 the simple case of an Ada record with discriminant, but it can be the
486 array in the case of an unconstrained array.
488 In the latter case, we need the fat pointer, because the bounds of the
489 array can only be accessed from it. However, we rely here on the fact that
490 the expression for the array contains the dereference of the fat pointer
491 that obtained the array pointer.
493 Accordingly, when looking for the object to substitute in place of
494 a PLACEHOLDER_EXPR, we look down the first operand of the expression
495 passed as the second operand to WITH_RECORD_EXPR until we find something
496 of the desired type or reach a constant. */
498 /* Denotes a record to later be supplied with a WITH_RECORD_EXPR when
499 evaluating this expression. The type of this expression is used to
500 find the record to replace it. */
501 DEFTREECODE (PLACEHOLDER_EXPR, "placeholder_expr", "x", 0)
503 /* Provide an expression that references a record to be used in place
504 of a PLACEHOLDER_EXPR. The record to be used is the record within
505 operand 1 that has the same type as the PLACEHOLDER_EXPR in
507 DEFTREECODE (WITH_RECORD_EXPR, "with_record_expr", "e", 2)
509 /* Simple arithmetic. Operands must have the same machine mode
510 and the value shares that mode. */
511 DEFTREECODE (PLUS_EXPR, "plus_expr", "2", 2)
512 DEFTREECODE (MINUS_EXPR, "minus_expr", "2", 2)
513 DEFTREECODE (MULT_EXPR, "mult_expr", "2", 2)
515 /* Division for integer result that rounds the quotient toward zero. */
516 /* Operands must have the same machine mode.
517 In principle they may be real, but that is not currently supported.
518 The result is always fixed point, and it has the same type as the
519 operands if they are fixed point. */
520 DEFTREECODE (TRUNC_DIV_EXPR, "trunc_div_expr", "2", 2)
522 /* Division for integer result that rounds the quotient toward infinity. */
523 DEFTREECODE (CEIL_DIV_EXPR, "ceil_div_expr", "2", 2)
525 /* Division for integer result that rounds toward minus infinity. */
526 DEFTREECODE (FLOOR_DIV_EXPR, "floor_div_expr", "2", 2)
528 /* Division for integer result that rounds toward nearest integer. */
529 DEFTREECODE (ROUND_DIV_EXPR, "round_div_expr", "2", 2)
531 /* Four kinds of remainder that go with the four kinds of division. */
532 DEFTREECODE (TRUNC_MOD_EXPR, "trunc_mod_expr", "2", 2)
533 DEFTREECODE (CEIL_MOD_EXPR, "ceil_mod_expr", "2", 2)
534 DEFTREECODE (FLOOR_MOD_EXPR, "floor_mod_expr", "2", 2)
535 DEFTREECODE (ROUND_MOD_EXPR, "round_mod_expr", "2", 2)
537 /* Division for real result. The two operands must have the same type.
538 In principle they could be integers, but currently only real
539 operands are supported. The result must have the same type
541 DEFTREECODE (RDIV_EXPR, "rdiv_expr", "2", 2)
543 /* Division which is not supposed to need rounding.
544 Used for pointer subtraction in C. */
545 DEFTREECODE (EXACT_DIV_EXPR, "exact_div_expr", "2", 2)
547 /* Conversion of real to fixed point: four ways to round,
548 like the four ways to divide.
549 CONVERT_EXPR can also be used to convert a real to an integer,
550 and that is what is used in languages that do not have ways of
551 specifying which of these is wanted. Maybe these are not needed. */
552 DEFTREECODE (FIX_TRUNC_EXPR, "fix_trunc_expr", "1", 1)
553 DEFTREECODE (FIX_CEIL_EXPR, "fix_ceil_expr", "1", 1)
554 DEFTREECODE (FIX_FLOOR_EXPR, "fix_floor_expr", "1", 1)
555 DEFTREECODE (FIX_ROUND_EXPR, "fix_round_expr", "1", 1)
557 /* Conversion of an integer to a real. */
558 DEFTREECODE (FLOAT_EXPR, "float_expr", "1", 1)
560 /* Exponentiation. Operands may have any types;
561 constraints on value type are not known yet. */
562 DEFTREECODE (EXPON_EXPR, "expon_expr", "2", 2)
564 /* Unary negation. Value has same type as operand. */
565 DEFTREECODE (NEGATE_EXPR, "negate_expr", "1", 1)
567 DEFTREECODE (MIN_EXPR, "min_expr", "2", 2)
568 DEFTREECODE (MAX_EXPR, "max_expr", "2", 2)
569 DEFTREECODE (ABS_EXPR, "abs_expr", "1", 1)
570 DEFTREECODE (FFS_EXPR, "ffs_expr", "1", 1)
572 /* Shift operations for shift and rotate.
573 Shift is supposed to mean logical shift if done on an
574 unsigned type, arithmetic shift on a signed type.
575 The second operand is the number of bits to
576 shift by, and must always have mode SImode.
577 The result has the same mode as the first operand. */
578 DEFTREECODE (LSHIFT_EXPR, "alshift_expr", "2", 2)
579 DEFTREECODE (RSHIFT_EXPR, "arshift_expr", "2", 2)
580 DEFTREECODE (LROTATE_EXPR, "lrotate_expr", "2", 2)
581 DEFTREECODE (RROTATE_EXPR, "rrotate_expr", "2", 2)
583 /* Bitwise operations. Operands have same mode as result. */
584 DEFTREECODE (BIT_IOR_EXPR, "bit_ior_expr", "2", 2)
585 DEFTREECODE (BIT_XOR_EXPR, "bit_xor_expr", "2", 2)
586 DEFTREECODE (BIT_AND_EXPR, "bit_and_expr", "2", 2)
587 DEFTREECODE (BIT_ANDTC_EXPR, "bit_andtc_expr", "2", 2)
588 DEFTREECODE (BIT_NOT_EXPR, "bit_not_expr", "1", 1)
590 /* Combination of boolean values or of integers considered only
591 as zero or nonzero. ANDIF and ORIF allow the second operand
592 not to be computed if the value of the expression is determined
593 from the first operand. AND, OR, and XOR always compute the second
594 operand whether its value is needed or not (for side effects). */
595 DEFTREECODE (TRUTH_ANDIF_EXPR, "truth_andif_expr", "e", 2)
596 DEFTREECODE (TRUTH_ORIF_EXPR, "truth_orif_expr", "e", 2)
597 DEFTREECODE (TRUTH_AND_EXPR, "truth_and_expr", "e", 2)
598 DEFTREECODE (TRUTH_OR_EXPR, "truth_or_expr", "e", 2)
599 DEFTREECODE (TRUTH_XOR_EXPR, "truth_xor_expr", "e", 2)
600 DEFTREECODE (TRUTH_NOT_EXPR, "truth_not_expr", "e", 1)
602 /* Relational operators.
603 `EQ_EXPR' and `NE_EXPR' are allowed for any types.
604 The others are allowed only for integer (or pointer or enumeral)
606 In all cases the operands will have the same type,
607 and the value is always the type used by the language for booleans. */
608 DEFTREECODE (LT_EXPR, "lt_expr", "<", 2)
609 DEFTREECODE (LE_EXPR, "le_expr", "<", 2)
610 DEFTREECODE (GT_EXPR, "gt_expr", "<", 2)
611 DEFTREECODE (GE_EXPR, "ge_expr", "<", 2)
612 DEFTREECODE (EQ_EXPR, "eq_expr", "<", 2)
613 DEFTREECODE (NE_EXPR, "ne_expr", "<", 2)
615 /* Operations for Pascal sets. Not used now. */
616 DEFTREECODE (IN_EXPR, "in_expr", "2", 2)
617 DEFTREECODE (SET_LE_EXPR, "set_le_expr", "<", 2)
618 DEFTREECODE (CARD_EXPR, "card_expr", "1", 1)
619 DEFTREECODE (RANGE_EXPR, "range_expr", "2", 2)
621 /* Represents a conversion of type of a value.
622 All conversions, including implicit ones, must be
623 represented by CONVERT_EXPR nodes. */
624 DEFTREECODE (CONVERT_EXPR, "convert_expr", "1", 1)
626 /* Represents a conversion expected to require no code to be generated. */
627 DEFTREECODE (NOP_EXPR, "nop_expr", "1", 1)
629 /* Value is same as argument, but guaranteed not an lvalue. */
630 DEFTREECODE (NON_LVALUE_EXPR, "non_lvalue_expr", "1", 1)
632 /* Represents something we computed once and will use multiple times.
633 First operand is that expression. Second is the function decl
634 in which the SAVE_EXPR was created. The third operand is the RTL,
635 nonzero only after the expression has been computed. */
636 DEFTREECODE (SAVE_EXPR, "save_expr", "e", 3)
638 /* Represents something whose RTL has already been expanded
639 as a sequence which should be emitted when this expression is expanded.
640 The first operand is the RTL to emit. It is the first of a chain of insns.
641 The second is the RTL expression for the result. */
642 DEFTREECODE (RTL_EXPR, "rtl_expr", "e", 2)
644 /* & in C. Value is the address at which the operand's value resides.
645 Operand may have any mode. Result mode is Pmode. */
646 DEFTREECODE (ADDR_EXPR, "addr_expr", "e", 1)
648 /* Non-lvalue reference or pointer to an object. */
649 DEFTREECODE (REFERENCE_EXPR, "reference_expr", "e", 1)
651 /* Operand is a function constant; result is a function variable value
652 of typeEPmode. Used only for languages that need static chains. */
653 DEFTREECODE (ENTRY_VALUE_EXPR, "entry_value_expr", "e", 1)
655 /* Given two real or integer operands of the same type,
656 returns a complex value of the corresponding complex type. */
657 DEFTREECODE (COMPLEX_EXPR, "complex_expr", "2", 2)
659 /* Complex conjugate of operand. Used only on complex types.
660 The value has the same type as the operand. */
661 DEFTREECODE (CONJ_EXPR, "conj_expr", "1", 1)
663 /* Used only on an operand of complex type, these return
664 a value of the corresponding component type. */
665 DEFTREECODE (REALPART_EXPR, "realpart_expr", "1", 1)
666 DEFTREECODE (IMAGPART_EXPR, "imagpart_expr", "1", 1)
668 /* Nodes for ++ and -- in C.
669 The second arg is how much to increment or decrement by.
670 For a pointer, it would be the size of the object pointed to. */
671 DEFTREECODE (PREDECREMENT_EXPR, "predecrement_expr", "e", 2)
672 DEFTREECODE (PREINCREMENT_EXPR, "preincrement_expr", "e", 2)
673 DEFTREECODE (POSTDECREMENT_EXPR, "postdecrement_expr", "e", 2)
674 DEFTREECODE (POSTINCREMENT_EXPR, "postincrement_expr", "e", 2)
676 /* These types of expressions have no useful value,
677 and always have side effects. */
679 /* A label definition, encapsulated as a statement.
680 Operand 0 is the LABEL_DECL node for the label that appears here.
681 The type should be void and the value should be ignored. */
682 DEFTREECODE (LABEL_EXPR, "label_expr", "s", 1)
684 /* GOTO. Operand 0 is a LABEL_DECL node.
685 The type should be void and the value should be ignored. */
686 DEFTREECODE (GOTO_EXPR, "goto_expr", "s", 1)
688 /* RETURN. Evaluates operand 0, then returns from the current function.
689 Presumably that operand is an assignment that stores into the
690 RESULT_DECL that hold the value to be returned.
691 The operand may be null.
692 The type should be void and the value should be ignored. */
693 DEFTREECODE (RETURN_EXPR, "return_expr", "s", 1)
695 /* Exit the inner most loop conditionally. Operand 0 is the condition.
696 The type should be void and the value should be ignored. */
697 DEFTREECODE (EXIT_EXPR, "exit_expr", "s", 1)
699 /* A loop. Operand 0 is the body of the loop.
700 It must contain an EXIT_EXPR or is an infinite loop.
701 The type should be void and the value should be ignored. */
702 DEFTREECODE (LOOP_EXPR, "loop_expr", "s", 1)