1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
|
/* This file contains the definitions and documentation for the
tree codes used in the GNU C compiler.
Copyright (C) 1987, 1988, 1993, 1995 Free Software Foundation, Inc.
This file is part of GNU CC.
GNU CC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
GNU CC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GNU CC; see the file COPYING. If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
/* The third argument can be:
"x" for an exceptional code (fits no category).
"t" for a type object code.
"b" for a lexical block.
"c" for codes for constants.
"d" for codes for declarations (also serving as variable refs).
"r" for codes for references to storage.
"<" for codes for comparison expressions.
"1" for codes for unary arithmetic expressions.
"2" for codes for binary arithmetic expressions.
"s" for codes for expressions with inherent side effects.
"e" for codes for other kinds of expressions. */
/* For `r', `e', `<', `1', `2', `s' and `x' nodes,
the 4th element is the number of argument slots to allocate.
This determines the size of the tree node object. */
/* Any erroneous construct is parsed into a node of this type.
This type of node is accepted without complaint in all contexts
by later parsing activities, to avoid multiple error messages
for one error.
No fields in these nodes are used except the TREE_CODE. */
DEFTREECODE (ERROR_MARK, "error_mark", "x", 0)
/* Used to represent a name (such as, in the DECL_NAME of a decl node).
Internally it looks like a STRING_CST node.
There is only one IDENTIFIER_NODE ever made for any particular name.
Use `get_identifier' to get it (or create it, the first time). */
DEFTREECODE (IDENTIFIER_NODE, "identifier_node", "x", -1)
/* Used to hold information to identify an operator (or combination
of two operators) considered as a `noun' rather than a `verb'.
The first operand is encoded in the TREE_TYPE field. */
DEFTREECODE (OP_IDENTIFIER, "op_identifier", "x", 2)
/* Has the TREE_VALUE and TREE_PURPOSE fields. */
/* These nodes are made into lists by chaining through the
TREE_CHAIN field. The elements of the list live in the
TREE_VALUE fields, while TREE_PURPOSE fields are occasionally
used as well to get the effect of Lisp association lists. */
DEFTREECODE (TREE_LIST, "tree_list", "x", 2)
/* These nodes contain an array of tree nodes. */
DEFTREECODE (TREE_VEC, "tree_vec", "x", 2)
/* A symbol binding block. These are arranged in a tree,
where the BLOCK_SUBBLOCKS field contains a chain of subblocks
chained through the BLOCK_CHAIN field.
BLOCK_SUPERCONTEXT points to the parent block.
For a block which represents the outermost scope of a function, it
points to the FUNCTION_DECL node.
BLOCK_VARS points to a chain of decl nodes.
BLOCK_TYPE_TAGS points to a chain of types which have their own names.
BLOCK_CHAIN points to the next BLOCK at the same level.
BLOCK_ABSTRACT_ORIGIN points to the original (abstract) tree node which
this block is an instance of, or else is NULL to indicate that this
block is not an instance of anything else. When non-NULL, the value
could either point to another BLOCK node or it could point to a
FUNCTION_DECL node (e.g. in the case of a block representing the
outermost scope of a particular inlining of a function).
BLOCK_ABSTRACT is non-zero if the block represents an abstract
instance of a block (i.e. one which is nested within an abstract
instance of a inline function. */
DEFTREECODE (BLOCK, "block", "b", 0)
/* Each data type is represented by a tree node whose code is one of
the following: */
/* Each node that represents a data type has a component TYPE_SIZE
containing a tree that is an expression for the size in bits.
The TYPE_MODE contains the machine mode for values of this type.
The TYPE_POINTER_TO field contains a type for a pointer to this type,
or zero if no such has been created yet.
The TYPE_NEXT_VARIANT field is used to chain together types
that are variants made by type modifiers such as "const" and "volatile".
The TYPE_MAIN_VARIANT field, in any member of such a chain,
points to the start of the chain.
The TYPE_NONCOPIED_PARTS field is a list specifying which parts
of an object of this type should *not* be copied by assignment.
The TREE_PURPOSE of each element is the offset of the part
and the TREE_VALUE is the size in bits of the part.
The TYPE_NAME field contains info on the name used in the program
for this type (for GDB symbol table output). It is either a
TYPE_DECL node, for types that are typedefs, or an IDENTIFIER_NODE
in the case of structs, unions or enums that are known with a tag,
or zero for types that have no special name.
The TYPE_CONTEXT for any sort of type which could have a name or
which could have named members (e.g. tagged types in C/C++) will
point to the node which represents the scope of the given type, or
will be NULL_TREE if the type has "file scope". For most types, this
will point to a BLOCK node or a FUNCTION_DECL node, but it could also
point to a FUNCTION_TYPE node (for types whose scope is limited to the
formal parameter list of some function type specification) or it
could point to a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE node
(for C++ "member" types).
For non-tagged-types, TYPE_CONTEXT need not be set to anything in
particular, since any type which is of some type category (e.g.
an array type or a function type) which cannot either have a name
itself or have named members doesn't really have a "scope" per se.
The TREE_CHAIN field is used as a forward-references to names for
ENUMERAL_TYPE, RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE nodes;
see below. */
DEFTREECODE (VOID_TYPE, "void_type", "t", 0) /* The void type in C */
/* Integer types in all languages, including char in C.
Also used for sub-ranges of other discrete types.
Has components TYPE_MIN_VALUE, TYPE_MAX_VALUE (expressions, inclusive)
and TYPE_PRECISION (number of bits used by this type).
In the case of a subrange type in Pascal, the TREE_TYPE
of this will point at the supertype (another INTEGER_TYPE,
or an ENUMERAL_TYPE, CHAR_TYPE, or BOOLEAN_TYPE).
Otherwise, the TREE_TYPE is zero. */
DEFTREECODE (INTEGER_TYPE, "integer_type", "t", 0)
/* C's float and double. Different floating types are distinguished
by machine mode and by the TYPE_SIZE and the TYPE_PRECISION. */
DEFTREECODE (REAL_TYPE, "real_type", "t", 0)
/* Complex number types. The TREE_TYPE field is the data type
of the real and imaginary parts. */
DEFTREECODE (COMPLEX_TYPE, "complex_type", "t", 0)
/* C enums. The type node looks just like an INTEGER_TYPE node.
The symbols for the values of the enum type are defined by
CONST_DECL nodes, but the type does not point to them;
however, the TYPE_VALUES is a list in which each element's TREE_PURPOSE
is a name and the TREE_VALUE is the value (an INTEGER_CST node). */
/* A forward reference `enum foo' when no enum named foo is defined yet
has zero (a null pointer) in its TYPE_SIZE. The tag name is in
the TYPE_NAME field. If the type is later defined, the normal
fields are filled in.
RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE forward refs are
treated similarly. */
DEFTREECODE (ENUMERAL_TYPE, "enumeral_type", "t", 0)
/* Pascal's boolean type (true or false are the only values);
no special fields needed. */
DEFTREECODE (BOOLEAN_TYPE, "boolean_type", "t", 0)
/* CHAR in Pascal; not used in C.
No special fields needed. */
DEFTREECODE (CHAR_TYPE, "char_type", "t", 0)
/* All pointer-to-x types have code POINTER_TYPE.
The TREE_TYPE points to the node for the type pointed to. */
DEFTREECODE (POINTER_TYPE, "pointer_type", "t", 0)
/* An offset is a pointer relative to an object.
The TREE_TYPE field is the type of the object at the offset.
The TYPE_OFFSET_BASETYPE points to the node for the type of object
that the offset is relative to. */
DEFTREECODE (OFFSET_TYPE, "offset_type", "t", 0)
/* A reference is like a pointer except that it is coerced
automatically to the value it points to. Used in C++. */
DEFTREECODE (REFERENCE_TYPE, "reference_type", "t", 0)
/* METHOD_TYPE is the type of a function which takes an extra first
argument for "self", which is not present in the declared argument list.
The TREE_TYPE is the return type of the method. The TYPE_METHOD_BASETYPE
is the type of "self". TYPE_ARG_TYPES is the real argument list, which
includes the hidden argument for "self". */
DEFTREECODE (METHOD_TYPE, "method_type", "t", 0)
/* Used for Pascal; details not determined right now. */
DEFTREECODE (FILE_TYPE, "file_type", "t", 0)
/* Types of arrays. Special fields:
TREE_TYPE Type of an array element.
TYPE_DOMAIN Type to index by.
Its range of values specifies the array length.
TYPE_SEP Expression for units from one elt to the next.
TYPE_SEP_UNIT Number of bits in a unit for previous.
The field TYPE_POINTER_TO (TREE_TYPE (array_type)) is always nonzero
and holds the type to coerce a value of that array type to in C.
TYPE_STRING_FLAG indicates a string (in contrast to an array of chars)
in languages (such as Chill) that make a distinction. */
/* Array types in C or Pascal */
DEFTREECODE (ARRAY_TYPE, "array_type", "t", 0)
/* Types of sets for Pascal. Special fields are the same as
in an array type. The target type is always a boolean type.
Used for both bitstrings and powersets in Chill;
TYPE_STRING_FLAG indicates a bitstring. */
DEFTREECODE (SET_TYPE, "set_type", "t", 0)
/* Struct in C, or record in Pascal. */
/* Special fields:
TYPE_FIELDS chain of FIELD_DECLs for the fields of the struct,
and VAR_DECLs, TYPE_DECLs and CONST_DECLs for record-scope variables,
types and enumerators.
A few may need to be added for Pascal. */
/* See the comment above, before ENUMERAL_TYPE, for how
forward references to struct tags are handled in C. */
DEFTREECODE (RECORD_TYPE, "record_type", "t", 0)
/* Union in C. Like a struct, except that the offsets of the fields
will all be zero. */
/* See the comment above, before ENUMERAL_TYPE, for how
forward references to union tags are handled in C. */
DEFTREECODE (UNION_TYPE, "union_type", "t", 0) /* C union type */
/* Similar to UNION_TYPE, except that the expressions in DECL_QUALIFIER
in each FIELD_DECL determine what the union contains. The first
field whose DECL_QUALIFIER expression is true is deemed to occupy
the union. */
DEFTREECODE (QUAL_UNION_TYPE, "qual_union_type", "t", 0)
/* Type of functions. Special fields:
TREE_TYPE type of value returned.
TYPE_ARG_TYPES list of types of arguments expected.
this list is made of TREE_LIST nodes.
Types of "Procedures" in languages where they are different from functions
have code FUNCTION_TYPE also, but then TREE_TYPE is zero or void type. */
DEFTREECODE (FUNCTION_TYPE, "function_type", "t", 0)
/* This is a language-specific kind of type.
Its meaning is defined by the language front end.
layout_type does not know how to lay this out,
so the front-end must do so manually. */
DEFTREECODE (LANG_TYPE, "lang_type", "t", 0)
/* Expressions */
/* First, the constants. */
/* Contents are in TREE_INT_CST_LOW and TREE_INT_CST_HIGH fields,
32 bits each, giving us a 64 bit constant capability.
Note: constants of type char in Pascal are INTEGER_CST,
and so are pointer constants such as nil in Pascal or NULL in C.
`(int *) 1' in C also results in an INTEGER_CST. */
DEFTREECODE (INTEGER_CST, "integer_cst", "c", 2)
/* Contents are in TREE_REAL_CST field. Also there is TREE_CST_RTL. */
DEFTREECODE (REAL_CST, "real_cst", "c", 3)
/* Contents are in TREE_REALPART and TREE_IMAGPART fields,
whose contents are other constant nodes.
Also there is TREE_CST_RTL. */
DEFTREECODE (COMPLEX_CST, "complex_cst", "c", 3)
/* Contents are TREE_STRING_LENGTH and TREE_STRING_POINTER fields.
Also there is TREE_CST_RTL. */
DEFTREECODE (STRING_CST, "string_cst", "c", 3)
/* Declarations. All references to names are represented as ..._DECL nodes.
The decls in one binding context are chained through the TREE_CHAIN field.
Each DECL has a DECL_NAME field which contains an IDENTIFIER_NODE.
(Some decls, most often labels, may have zero as the DECL_NAME).
DECL_CONTEXT points to the node representing the context in which
this declaration has its scope. For FIELD_DECLs, this is the
RECORD_TYPE, UNION_TYPE, or QUAL_UNION_TYPE node that the field
is a member of. For VAR_DECL, PARM_DECL, FUNCTION_DECL, LABEL_DECL,
and CONST_DECL nodes, this points to either the FUNCTION_DECL for the
containing function, the RECORD_TYPE or UNION_TYPE for the containing
type, or NULL_TREE if the given decl has "file scope".
DECL_ABSTRACT_ORIGIN, if non-NULL, points to the original (abstract)
..._DECL node of which this decl is an (inlined or template expanded)
instance.
The TREE_TYPE field holds the data type of the object, when relevant.
LABEL_DECLs have no data type. For TYPE_DECL, the TREE_TYPE field
contents are the type whose name is being declared.
The DECL_ALIGN, DECL_SIZE,
and DECL_MODE fields exist in decl nodes just as in type nodes.
They are unused in LABEL_DECL, TYPE_DECL and CONST_DECL nodes.
DECL_OFFSET holds an integer number of bits offset for the location.
DECL_VOFFSET holds an expression for a variable offset; it is
to be multiplied by DECL_VOFFSET_UNIT (an integer).
These fields are relevant only in FIELD_DECLs and PARM_DECLs.
DECL_INITIAL holds the value to initialize a variable to,
or the value of a constant. For a function, it holds the body
(a node of type BLOCK representing the function's binding contour
and whose body contains the function's statements.) For a LABEL_DECL
in C, it is a flag, nonzero if the label's definition has been seen.
PARM_DECLs use a special field:
DECL_ARG_TYPE is the type in which the argument is actually
passed, which may be different from its type within the function.
FUNCTION_DECLs use four special fields:
DECL_ARGUMENTS holds a chain of PARM_DECL nodes for the arguments.
DECL_RESULT holds a RESULT_DECL node for the value of a function,
or it is 0 for a function that returns no value.
(C functions returning void have zero here.)
DECL_RESULT_TYPE holds the type in which the result is actually
returned. This is usually the same as the type of DECL_RESULT,
but (1) it may be a wider integer type and
(2) it remains valid, for the sake of inlining, even after the
function's compilation is done.
DECL_FUNCTION_CODE is a code number that is nonzero for
built-in functions. Its value is an enum built_in_function
that says which built-in function it is.
DECL_SOURCE_FILE holds a filename string and DECL_SOURCE_LINE
holds a line number. In some cases these can be the location of
a reference, if no definition has been seen.
DECL_ABSTRACT is non-zero if the decl represents an abstract instance
of a decl (i.e. one which is nested within an abstract instance of a
inline function. */
DEFTREECODE (FUNCTION_DECL, "function_decl", "d", 0)
DEFTREECODE (LABEL_DECL, "label_decl", "d", 0)
DEFTREECODE (CONST_DECL, "const_decl", "d", 0)
DEFTREECODE (TYPE_DECL, "type_decl", "d", 0)
DEFTREECODE (VAR_DECL, "var_decl", "d", 0)
DEFTREECODE (PARM_DECL, "parm_decl", "d", 0)
DEFTREECODE (RESULT_DECL, "result_decl", "d", 0)
DEFTREECODE (FIELD_DECL, "field_decl", "d", 0)
/* References to storage. */
/* Value is structure or union component.
Operand 0 is the structure or union (an expression);
operand 1 is the field (a node of type FIELD_DECL). */
DEFTREECODE (COMPONENT_REF, "component_ref", "r", 2)
/* Reference to a group of bits within an object. Similar to COMPONENT_REF
except the position is given explicitly rather than via a FIELD_DECL.
Operand 0 is the structure or union expression;
operand 1 is a tree giving the number of bits being referenced;
operand 2 is a tree giving the position of the first referenced bit.
The field can be either a signed or unsigned field;
TREE_UNSIGNED says which. */
DEFTREECODE (BIT_FIELD_REF, "bit_field_ref", "r", 3)
/* C unary `*' or Pascal `^'. One operand, an expression for a pointer. */
DEFTREECODE (INDIRECT_REF, "indirect_ref", "r", 1)
/* Pascal `^` on a file. One operand, an expression for the file. */
DEFTREECODE (BUFFER_REF, "buffer_ref", "r", 1)
/* Array indexing in languages other than C.
Operand 0 is the array; operand 1 is a list of indices
stored as a chain of TREE_LIST nodes. */
DEFTREECODE (ARRAY_REF, "array_ref", "r", 2)
/* Constructor: return an aggregate value made from specified components.
In C, this is used only for structure and array initializers.
Also used for SET_TYPE in Chill (and potentially Pascal).
The first "operand" is really a pointer to the RTL,
for constant constructors only.
The second operand is a list of component values
made out of a chain of TREE_LIST nodes.
For ARRAY_TYPE:
The TREE_PURPOSE of each node is the corresponding index.
If the TREE_PURPOSE is a RANGE_EXPR, it is a short-hand for many nodes,
one for each index in the range. (If the corresponding TREE_VALUE
has side-effects, they are evaluated once for each element. Wrap the
value in a SAVE_EXPR if you want to evaluate side effects only once.)
For RECORD_TYPE, UNION_TYPE, or QUAL_UNION_TYPE:
The TREE_PURPOSE of each node is a FIELD_DECL.
For SET_TYPE:
The TREE_VALUE specifies a value (index) in the set that is true.
If TREE_PURPOSE is non-NULL, it specifies the lower limit of a
range of true values. Elements not listed are false (not in the set). */
DEFTREECODE (CONSTRUCTOR, "constructor", "e", 2)
/* The expression types are mostly straightforward, with the fourth argument
of DEFTREECODE saying how many operands there are.
Unless otherwise specified, the operands are expressions and the
types of all the operands and the expression must all be the same. */
/* Contains two expressions to compute, one followed by the other.
the first value is ignored. The second one's value is used. The
type of the first expression need not agree with the other types. */
DEFTREECODE (COMPOUND_EXPR, "compound_expr", "e", 2)
/* Assignment expression. Operand 0 is the what to set; 1, the new value. */
DEFTREECODE (MODIFY_EXPR, "modify_expr", "e", 2)
/* Initialization expression. Operand 0 is the variable to initialize;
Operand 1 is the initializer. */
DEFTREECODE (INIT_EXPR, "init_expr", "e", 2)
/* For TARGET_EXPR, operand 0 is the target of an initialization,
operand 1 is the initializer for the target,
and operand 2 is the cleanup for this node, if any.
and operand 3 is the saved initializer after this node has been
expanded once, this is so we can re-expand the tree later. */
DEFTREECODE (TARGET_EXPR, "target_expr", "e", 4)
/* Conditional expression ( ... ? ... : ... in C).
Operand 0 is the condition.
Operand 1 is the then-value.
Operand 2 is the else-value.
Operand 0 may be of any types, but the types of operands 1 and 2
must be the same and the same as the the of this expression. */
DEFTREECODE (COND_EXPR, "cond_expr", "e", 3)
/* Declare local variables, including making RTL and allocating space.
Operand 0 is a chain of VAR_DECL nodes for the variables.
Operand 1 is the body, the expression to be computed using
the variables. The value of operand 1 becomes that of the BIND_EXPR.
Operand 2 is the BLOCK that corresponds to these bindings
for debugging purposes. If this BIND_EXPR is actually expanded,
that sets the TREE_USED flag in the BLOCK.
The BIND_EXPR is not responsible for informing parsers
about these variables. If the body is coming from the input file,
then the code that creates the BIND_EXPR is also responsible for
informing the parser of the variables.
If the BIND_EXPR is ever expanded, its TREE_USED flag is set.
This tells the code for debugging symbol tables not to ignore the BIND_EXPR.
If the BIND_EXPR should be output for debugging but will not be expanded,
set the TREE_USED flag by hand.
In order for the BIND_EXPR to be known at all, the code that creates it
must also install it as a subblock in the tree of BLOCK
nodes for the function. */
DEFTREECODE (BIND_EXPR, "bind_expr", "e", 3)
/* Function call. Operand 0 is the function.
Operand 1 is the argument list, a list of expressions
made out of a chain of TREE_LIST nodes.
There is no operand 2. That slot is used for the
CALL_EXPR_RTL macro (see preexpand_calls). */
DEFTREECODE (CALL_EXPR, "call_expr", "e", 3)
/* Call a method. Operand 0 is the method, whose type is a METHOD_TYPE.
Operand 1 is the expression for "self".
Operand 2 is the list of explicit arguments. */
DEFTREECODE (METHOD_CALL_EXPR, "method_call_expr", "e", 4)
/* Specify a value to compute along with its corresponding cleanup.
Operand 0 argument is an expression whose value needs a cleanup.
Operand 1 is an RTL_EXPR which will eventually represent that value.
Operand 2 is the cleanup expression for the object.
The RTL_EXPR is used in this expression, which is how the expression
manages to act on the proper value.
The cleanup is executed by the first enclosing CLEANUP_POINT_EXPR, if
it exists, otherwise it is the responsibility of the caller to manually
call expand_cleanups_to, as needed. */
DEFTREECODE (WITH_CLEANUP_EXPR, "with_cleanup_expr", "e", 3)
/* Specify a cleanup point.
Operand 0 is an expression that may have cleanups. If it does, those
cleanups are executed after the expression is expanded.
Note that if the expression is a reference to storage, it is forced out
of memory before the cleanups are run. This is necessary to handle
cases where the cleanups modify the storage referenced; in the
expression 't.i', if 't' is a struct with an integer member 'i' and a
cleanup which modifies 'i', the value of the expression depends on
whether the cleanup is run before or after 't.i' is evaluated. When
expand_expr is run on 't.i', it returns a MEM. This is not good enough;
the value of 't.i' must be forced out of memory.
As a consequence, the operand of a CLEANUP_POINT_EXPR must not have
BLKmode, because it will not be forced out of memory. */
DEFTREECODE (CLEANUP_POINT_EXPR, "cleanup_point_expr", "e", 1)
/* The following two codes are used in languages that have types where
the position and/or sizes of fields vary from object to object of the
same type, i.e., where some other field in the object contains a value
that is used in the computation of another field's offset or size.
For example, a record type with a discriminant in Ada is such a type.
This mechanism is also used to create "fat pointers" for unconstrained
array types in Ada; the fat pointer is a structure one of whose fields is
a pointer to the actual array type and the other field is a pointer to a
template, which is a structure containing the bounds of the array. The
bounds in the type pointed to by the first field in the fat pointer refer
to the values in the template.
These "self-references" are doing using a PLACEHOLDER_EXPR. This is a
node that will later be replaced with the object being referenced. Its type
is that of the object and selects which object to use from a chain of
references (see below).
When we wish to evaluate a size or offset, we check it is contains a
placeholder. If it does, we construct a WITH_RECORD_EXPR that contains
both the expression we wish to evaluate and an expression within which the
object may be found. The latter expression is the object itself in
the simple case of an Ada record with discriminant, but it can be the
array in the case of an unconstrained array.
In the latter case, we need the fat pointer, because the bounds of the
array can only be accessed from it. However, we rely here on the fact that
the expression for the array contains the dereference of the fat pointer
that obtained the array pointer.
Accordingly, when looking for the object to substitute in place of
a PLACEHOLDER_EXPR, we look down the first operand of the expression
passed as the second operand to WITH_RECORD_EXPR until we find something
of the desired type or reach a constant. */
/* Denotes a record to later be supplied with a WITH_RECORD_EXPR when
evaluating this expression. The type of this expression is used to
find the record to replace it. */
DEFTREECODE (PLACEHOLDER_EXPR, "placeholder_expr", "x", 0)
/* Provide an expression that references a record to be used in place
of a PLACEHOLDER_EXPR. The record to be used is the record within
operand 1 that has the same type as the PLACEHOLDER_EXPR in
operand 0. */
DEFTREECODE (WITH_RECORD_EXPR, "with_record_expr", "e", 2)
/* Simple arithmetic. */
DEFTREECODE (PLUS_EXPR, "plus_expr", "2", 2)
DEFTREECODE (MINUS_EXPR, "minus_expr", "2", 2)
DEFTREECODE (MULT_EXPR, "mult_expr", "2", 2)
/* Division for integer result that rounds the quotient toward zero. */
DEFTREECODE (TRUNC_DIV_EXPR, "trunc_div_expr", "2", 2)
/* Division for integer result that rounds the quotient toward infinity. */
DEFTREECODE (CEIL_DIV_EXPR, "ceil_div_expr", "2", 2)
/* Division for integer result that rounds toward minus infinity. */
DEFTREECODE (FLOOR_DIV_EXPR, "floor_div_expr", "2", 2)
/* Division for integer result that rounds toward nearest integer. */
DEFTREECODE (ROUND_DIV_EXPR, "round_div_expr", "2", 2)
/* Four kinds of remainder that go with the four kinds of division. */
DEFTREECODE (TRUNC_MOD_EXPR, "trunc_mod_expr", "2", 2)
DEFTREECODE (CEIL_MOD_EXPR, "ceil_mod_expr", "2", 2)
DEFTREECODE (FLOOR_MOD_EXPR, "floor_mod_expr", "2", 2)
DEFTREECODE (ROUND_MOD_EXPR, "round_mod_expr", "2", 2)
/* Division for real result. */
DEFTREECODE (RDIV_EXPR, "rdiv_expr", "2", 2)
/* Division which is not supposed to need rounding.
Used for pointer subtraction in C. */
DEFTREECODE (EXACT_DIV_EXPR, "exact_div_expr", "2", 2)
/* Conversion of real to fixed point: four ways to round,
like the four ways to divide.
CONVERT_EXPR can also be used to convert a real to an integer,
and that is what is used in languages that do not have ways of
specifying which of these is wanted. Maybe these are not needed. */
DEFTREECODE (FIX_TRUNC_EXPR, "fix_trunc_expr", "1", 1)
DEFTREECODE (FIX_CEIL_EXPR, "fix_ceil_expr", "1", 1)
DEFTREECODE (FIX_FLOOR_EXPR, "fix_floor_expr", "1", 1)
DEFTREECODE (FIX_ROUND_EXPR, "fix_round_expr", "1", 1)
/* Conversion of an integer to a real. */
DEFTREECODE (FLOAT_EXPR, "float_expr", "1", 1)
/* Exponentiation. Operands may have any types;
constraints on value type are not known yet. */
DEFTREECODE (EXPON_EXPR, "expon_expr", "2", 2)
/* Unary negation. */
DEFTREECODE (NEGATE_EXPR, "negate_expr", "1", 1)
DEFTREECODE (MIN_EXPR, "min_expr", "2", 2)
DEFTREECODE (MAX_EXPR, "max_expr", "2", 2)
DEFTREECODE (ABS_EXPR, "abs_expr", "1", 1)
DEFTREECODE (FFS_EXPR, "ffs_expr", "1", 1)
/* Shift operations for shift and rotate.
Shift is supposed to mean logical shift if done on an
unsigned type, arithmetic shift on a signed type.
The second operand is the number of bits to
shift by; it need not be the same type as the first operand and result. */
DEFTREECODE (LSHIFT_EXPR, "lshift_expr", "2", 2)
DEFTREECODE (RSHIFT_EXPR, "rshift_expr", "2", 2)
DEFTREECODE (LROTATE_EXPR, "lrotate_expr", "2", 2)
DEFTREECODE (RROTATE_EXPR, "rrotate_expr", "2", 2)
/* Bitwise operations. Operands have same mode as result. */
DEFTREECODE (BIT_IOR_EXPR, "bit_ior_expr", "2", 2)
DEFTREECODE (BIT_XOR_EXPR, "bit_xor_expr", "2", 2)
DEFTREECODE (BIT_AND_EXPR, "bit_and_expr", "2", 2)
DEFTREECODE (BIT_ANDTC_EXPR, "bit_andtc_expr", "2", 2)
DEFTREECODE (BIT_NOT_EXPR, "bit_not_expr", "1", 1)
/* Combination of boolean values or of integers considered only
as zero or nonzero. ANDIF and ORIF allow the second operand
not to be computed if the value of the expression is determined
from the first operand. AND, OR, and XOR always compute the second
operand whether its value is needed or not (for side effects). */
DEFTREECODE (TRUTH_ANDIF_EXPR, "truth_andif_expr", "e", 2)
DEFTREECODE (TRUTH_ORIF_EXPR, "truth_orif_expr", "e", 2)
DEFTREECODE (TRUTH_AND_EXPR, "truth_and_expr", "e", 2)
DEFTREECODE (TRUTH_OR_EXPR, "truth_or_expr", "e", 2)
DEFTREECODE (TRUTH_XOR_EXPR, "truth_xor_expr", "e", 2)
DEFTREECODE (TRUTH_NOT_EXPR, "truth_not_expr", "e", 1)
/* Relational operators.
`EQ_EXPR' and `NE_EXPR' are allowed for any types.
The others are allowed only for integer (or pointer or enumeral)
or real types.
In all cases the operands will have the same type,
and the value is always the type used by the language for booleans. */
DEFTREECODE (LT_EXPR, "lt_expr", "<", 2)
DEFTREECODE (LE_EXPR, "le_expr", "<", 2)
DEFTREECODE (GT_EXPR, "gt_expr", "<", 2)
DEFTREECODE (GE_EXPR, "ge_expr", "<", 2)
DEFTREECODE (EQ_EXPR, "eq_expr", "<", 2)
DEFTREECODE (NE_EXPR, "ne_expr", "<", 2)
/* Operations for Pascal sets. Not used now. */
DEFTREECODE (IN_EXPR, "in_expr", "2", 2)
DEFTREECODE (SET_LE_EXPR, "set_le_expr", "<", 2)
DEFTREECODE (CARD_EXPR, "card_expr", "1", 1)
DEFTREECODE (RANGE_EXPR, "range_expr", "2", 2)
/* Represents a conversion of type of a value.
All conversions, including implicit ones, must be
represented by CONVERT_EXPR or NOP_EXPR nodes. */
DEFTREECODE (CONVERT_EXPR, "convert_expr", "1", 1)
/* Represents a conversion expected to require no code to be generated. */
DEFTREECODE (NOP_EXPR, "nop_expr", "1", 1)
/* Value is same as argument, but guaranteed not an lvalue. */
DEFTREECODE (NON_LVALUE_EXPR, "non_lvalue_expr", "1", 1)
/* Represents something we computed once and will use multiple times.
First operand is that expression. Second is the function decl
in which the SAVE_EXPR was created. The third operand is the RTL,
nonzero only after the expression has been computed. */
DEFTREECODE (SAVE_EXPR, "save_expr", "e", 3)
/* For a UNSAVE_EXPR, operand 0 is the value to unsave. By unsave, we
mean that all _EXPRs such as TARGET_EXPRs, SAVE_EXPRs,
CALL_EXPRs and RTL_EXPRs, that are protected
from being evaluated more than once should be reset so that a new
expand_expr call of this expr will cause those to be re-evaluated.
This is useful when we want to reuse a tree in different places,
but where we must re-expand. */
DEFTREECODE (UNSAVE_EXPR, "unsave_expr", "e", 1)
/* Represents something whose RTL has already been expanded
as a sequence which should be emitted when this expression is expanded.
The first operand is the RTL to emit. It is the first of a chain of insns.
The second is the RTL expression for the result. */
DEFTREECODE (RTL_EXPR, "rtl_expr", "e", 2)
/* & in C. Value is the address at which the operand's value resides.
Operand may have any mode. Result mode is Pmode. */
DEFTREECODE (ADDR_EXPR, "addr_expr", "e", 1)
/* Non-lvalue reference or pointer to an object. */
DEFTREECODE (REFERENCE_EXPR, "reference_expr", "e", 1)
/* Operand is a function constant; result is a function variable value
of typeEPmode. Used only for languages that need static chains. */
DEFTREECODE (ENTRY_VALUE_EXPR, "entry_value_expr", "e", 1)
/* Given two real or integer operands of the same type,
returns a complex value of the corresponding complex type. */
DEFTREECODE (COMPLEX_EXPR, "complex_expr", "2", 2)
/* Complex conjugate of operand. Used only on complex types. */
DEFTREECODE (CONJ_EXPR, "conj_expr", "1", 1)
/* Used only on an operand of complex type, these return
a value of the corresponding component type. */
DEFTREECODE (REALPART_EXPR, "realpart_expr", "1", 1)
DEFTREECODE (IMAGPART_EXPR, "imagpart_expr", "1", 1)
/* Nodes for ++ and -- in C.
The second arg is how much to increment or decrement by.
For a pointer, it would be the size of the object pointed to. */
DEFTREECODE (PREDECREMENT_EXPR, "predecrement_expr", "e", 2)
DEFTREECODE (PREINCREMENT_EXPR, "preincrement_expr", "e", 2)
DEFTREECODE (POSTDECREMENT_EXPR, "postdecrement_expr", "e", 2)
DEFTREECODE (POSTINCREMENT_EXPR, "postincrement_expr", "e", 2)
/* These types of expressions have no useful value,
and always have side effects. */
/* A label definition, encapsulated as a statement.
Operand 0 is the LABEL_DECL node for the label that appears here.
The type should be void and the value should be ignored. */
DEFTREECODE (LABEL_EXPR, "label_expr", "s", 1)
/* GOTO. Operand 0 is a LABEL_DECL node.
The type should be void and the value should be ignored. */
DEFTREECODE (GOTO_EXPR, "goto_expr", "s", 1)
/* RETURN. Evaluates operand 0, then returns from the current function.
Presumably that operand is an assignment that stores into the
RESULT_DECL that hold the value to be returned.
The operand may be null.
The type should be void and the value should be ignored. */
DEFTREECODE (RETURN_EXPR, "return_expr", "s", 1)
/* Exit the inner most loop conditionally. Operand 0 is the condition.
The type should be void and the value should be ignored. */
DEFTREECODE (EXIT_EXPR, "exit_expr", "s", 1)
/* A loop. Operand 0 is the body of the loop.
It must contain an EXIT_EXPR or is an infinite loop.
The type should be void and the value should be ignored. */
DEFTREECODE (LOOP_EXPR, "loop_expr", "s", 1)
/*
Local variables:
mode:c
End:
*/
|