1 /* Common block and equivalence list handling
2 Copyright (C) 2000-2019 Free Software Foundation, Inc.
3 Contributed by Canqun Yang <canqun@nudt.edu.cn>
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
21 /* The core algorithm is based on Andy Vaught's g95 tree. Also the
22 way to build UNION_TYPE is borrowed from Richard Henderson.
24 Transform common blocks. An integral part of this is processing
25 equivalence variables. Equivalenced variables that are not in a
26 common block end up in a private block of their own.
28 Each common block or local equivalence list is declared as a union.
29 Variables within the block are represented as a field within the
30 block with the proper offset.
32 So if two variables are equivalenced, they just point to a common
35 Mathematically, laying out an equivalence block is equivalent to
36 solving a linear system of equations. The matrix is usually a
37 sparse matrix in which each row contains all zero elements except
38 for a +1 and a -1, a sort of a generalized Vandermonde matrix. The
39 matrix is usually block diagonal. The system can be
40 overdetermined, underdetermined or have a unique solution. If the
41 system is inconsistent, the program is not standard conforming.
42 The solution vector is integral, since all of the pivots are +1 or -1.
44 How we lay out an equivalence block is a little less complicated.
45 In an equivalence list with n elements, there are n-1 conditions to
46 be satisfied. The conditions partition the variables into what we
47 will call segments. If A and B are equivalenced then A and B are
48 in the same segment. If B and C are equivalenced as well, then A,
49 B and C are in a segment and so on. Each segment is a block of
50 memory that has one or more variables equivalenced in some way. A
51 common block is made up of a series of segments that are joined one
52 after the other. In the linear system, a segment is a block
55 To lay out a segment we first start with some variable and
56 determine its length. The first variable is assumed to start at
57 offset one and extends to however long it is. We then traverse the
58 list of equivalences to find an unused condition that involves at
59 least one of the variables currently in the segment.
61 Each equivalence condition amounts to the condition B+b=C+c where B
62 and C are the offsets of the B and C variables, and b and c are
63 constants which are nonzero for array elements, substrings or
64 structure components. So for
66 EQUIVALENCE(B(2), C(3))
68 B + 2*size of B's elements = C + 3*size of C's elements.
70 If B and C are known we check to see if the condition already
71 holds. If B is known we can solve for C. Since we know the length
72 of C, we can see if the minimum and maximum extents of the segment
73 are affected. Eventually, we make a full pass through the
74 equivalence list without finding any new conditions and the segment
77 At this point, the segment is added to the current common block.
78 Since we know the minimum extent of the segment, everything in the
79 segment is translated to its position in the common block. The
80 usual case here is that there are no equivalence statements and the
81 common block is series of segments with one variable each, which is
82 a diagonal matrix in the matrix formulation.
84 Each segment is described by a chain of segment_info structures. Each
85 segment_info structure describes the extents of a single variable within
86 the segment. This list is maintained in the order the elements are
87 positioned within the segment. If two elements have the same starting
88 offset the smaller will come first. If they also have the same size their
89 ordering is undefined.
91 Once all common blocks have been created, the list of equivalences
92 is examined for still-unused equivalence conditions. We create a
93 block for each merged equivalence list. */
98 #include "coretypes.h"
101 #include "gfortran.h"
103 #include "stringpool.h"
104 #include "fold-const.h"
105 #include "stor-layout.h"
107 #include "trans-types.h"
108 #include "trans-const.h"
109 #include "target-memory.h"
112 /* Holds a single variable in an equivalence set. */
113 typedef struct segment_info
116 HOST_WIDE_INT offset
;
117 HOST_WIDE_INT length
;
118 /* This will contain the field type until the field is created. */
120 struct segment_info
*next
;
123 static segment_info
* current_segment
;
125 /* Store decl of all common blocks in this translation unit; the first
126 tree is the identifier. */
127 static std::map
<tree
, tree
> gfc_map_of_all_commons
;
130 /* Make a segment_info based on a symbol. */
132 static segment_info
*
133 get_segment_info (gfc_symbol
* sym
, HOST_WIDE_INT offset
)
137 /* Make sure we've got the character length. */
138 if (sym
->ts
.type
== BT_CHARACTER
)
139 gfc_conv_const_charlen (sym
->ts
.u
.cl
);
141 /* Create the segment_info and fill it in. */
142 s
= XCNEW (segment_info
);
144 /* We will use this type when building the segment aggregate type. */
145 s
->field
= gfc_sym_type (sym
);
146 s
->length
= int_size_in_bytes (s
->field
);
153 /* Add a copy of a segment list to the namespace. This is specifically for
154 equivalence segments, so that dependency checking can be done on
155 equivalence group members. */
158 copy_equiv_list_to_ns (segment_info
*c
)
164 l
= XCNEW (gfc_equiv_list
);
166 l
->next
= c
->sym
->ns
->equiv_lists
;
167 c
->sym
->ns
->equiv_lists
= l
;
169 for (f
= c
; f
; f
= f
->next
)
171 s
= XCNEW (gfc_equiv_info
);
175 s
->offset
= f
->offset
;
176 s
->length
= f
->length
;
181 /* Add combine segment V and segment LIST. */
183 static segment_info
*
184 add_segments (segment_info
*list
, segment_info
*v
)
195 /* Find the location of the new element. */
198 if (v
->offset
< s
->offset
)
200 if (v
->offset
== s
->offset
201 && v
->length
<= s
->length
)
208 /* Insert the new element in between p and s. */
224 /* Construct mangled common block name from symbol name. */
226 /* We need the bind(c) flag to tell us how/if we should mangle the symbol
227 name. There are few calls to this function, so few places that this
228 would need to be added. At the moment, there is only one call, in
229 build_common_decl(). We can't attempt to look up the common block
230 because we may be building it for the first time and therefore, it won't
231 be in the common_root. We also need the binding label, if it's bind(c).
232 Therefore, send in the pointer to the common block, so whatever info we
233 have so far can be used. All of the necessary info should be available
234 in the gfc_common_head by now, so it should be accurate to test the
235 isBindC flag and use the binding label given if it is bind(c).
237 We may NOT know yet if it's bind(c) or not, but we can try at least.
238 Will have to figure out what to do later if it's labeled bind(c)
239 after this is called. */
242 gfc_sym_mangled_common_id (gfc_common_head
*com
)
245 char mangled_name
[GFC_MAX_MANGLED_SYMBOL_LEN
+ 1];
246 char name
[GFC_MAX_SYMBOL_LEN
+ 1];
248 /* Get the name out of the common block pointer. */
249 strcpy (name
, com
->name
);
251 /* If we're suppose to do a bind(c). */
252 if (com
->is_bind_c
== 1 && com
->binding_label
)
253 return get_identifier (com
->binding_label
);
255 if (strcmp (name
, BLANK_COMMON_NAME
) == 0)
256 return get_identifier (name
);
258 if (flag_underscoring
)
260 has_underscore
= strchr (name
, '_') != 0;
261 if (flag_second_underscore
&& has_underscore
)
262 snprintf (mangled_name
, sizeof mangled_name
, "%s__", name
);
264 snprintf (mangled_name
, sizeof mangled_name
, "%s_", name
);
266 return get_identifier (mangled_name
);
269 return get_identifier (name
);
273 /* Build a field declaration for a common variable or a local equivalence
277 build_field (segment_info
*h
, tree union_type
, record_layout_info rli
)
281 HOST_WIDE_INT offset
= h
->offset
;
282 unsigned HOST_WIDE_INT desired_align
, known_align
;
284 name
= get_identifier (h
->sym
->name
);
285 field
= build_decl (h
->sym
->declared_at
.lb
->location
,
286 FIELD_DECL
, name
, h
->field
);
287 known_align
= (offset
& -offset
) * BITS_PER_UNIT
;
288 if (known_align
== 0 || known_align
> BIGGEST_ALIGNMENT
)
289 known_align
= BIGGEST_ALIGNMENT
;
291 desired_align
= update_alignment_for_field (rli
, field
, known_align
);
292 if (desired_align
> known_align
)
293 DECL_PACKED (field
) = 1;
295 DECL_FIELD_CONTEXT (field
) = union_type
;
296 DECL_FIELD_OFFSET (field
) = size_int (offset
);
297 DECL_FIELD_BIT_OFFSET (field
) = bitsize_zero_node
;
298 SET_DECL_OFFSET_ALIGN (field
, known_align
);
300 rli
->offset
= size_binop (MAX_EXPR
, rli
->offset
,
301 size_binop (PLUS_EXPR
,
302 DECL_FIELD_OFFSET (field
),
303 DECL_SIZE_UNIT (field
)));
304 /* If this field is assigned to a label, we create another two variables.
305 One will hold the address of target label or format label. The other will
306 hold the length of format label string. */
307 if (h
->sym
->attr
.assign
)
312 gfc_allocate_lang_decl (field
);
313 GFC_DECL_ASSIGN (field
) = 1;
314 len
= gfc_create_var_np (gfc_charlen_type_node
,h
->sym
->name
);
315 addr
= gfc_create_var_np (pvoid_type_node
, h
->sym
->name
);
316 TREE_STATIC (len
) = 1;
317 TREE_STATIC (addr
) = 1;
318 DECL_INITIAL (len
) = build_int_cst (gfc_charlen_type_node
, -2);
319 gfc_set_decl_location (len
, &h
->sym
->declared_at
);
320 gfc_set_decl_location (addr
, &h
->sym
->declared_at
);
321 GFC_DECL_STRING_LEN (field
) = pushdecl_top_level (len
);
322 GFC_DECL_ASSIGN_ADDR (field
) = pushdecl_top_level (addr
);
325 /* If this field is volatile, mark it. */
326 if (h
->sym
->attr
.volatile_
)
329 TREE_THIS_VOLATILE (field
) = 1;
330 TREE_SIDE_EFFECTS (field
) = 1;
331 new_type
= build_qualified_type (TREE_TYPE (field
), TYPE_QUAL_VOLATILE
);
332 TREE_TYPE (field
) = new_type
;
339 /* Get storage for local equivalence. */
342 build_equiv_decl (tree union_type
, bool is_init
, bool is_saved
, bool is_auto
)
346 static int serial
= 0;
350 decl
= gfc_create_var (union_type
, "equiv");
351 TREE_STATIC (decl
) = 1;
352 GFC_DECL_COMMON_OR_EQUIV (decl
) = 1;
356 snprintf (name
, sizeof (name
), "equiv.%d", serial
++);
357 decl
= build_decl (input_location
,
358 VAR_DECL
, get_identifier (name
), union_type
);
359 DECL_ARTIFICIAL (decl
) = 1;
360 DECL_IGNORED_P (decl
) = 1;
362 if (!is_auto
&& (!gfc_can_put_var_on_stack (DECL_SIZE_UNIT (decl
))
364 TREE_STATIC (decl
) = 1;
366 TREE_ADDRESSABLE (decl
) = 1;
367 TREE_USED (decl
) = 1;
368 GFC_DECL_COMMON_OR_EQUIV (decl
) = 1;
370 /* The source location has been lost, and doesn't really matter.
371 We need to set it to something though. */
372 gfc_set_decl_location (decl
, &gfc_current_locus
);
374 gfc_add_decl_to_function (decl
);
380 /* Get storage for common block. */
383 build_common_decl (gfc_common_head
*com
, tree union_type
, bool is_init
)
385 tree decl
, identifier
;
387 identifier
= gfc_sym_mangled_common_id (com
);
388 decl
= gfc_map_of_all_commons
.count(identifier
)
389 ? gfc_map_of_all_commons
[identifier
] : NULL_TREE
;
391 /* Update the size of this common block as needed. */
392 if (decl
!= NULL_TREE
)
394 tree size
= TYPE_SIZE_UNIT (union_type
);
396 /* Named common blocks of the same name shall be of the same size
397 in all scoping units of a program in which they appear, but
398 blank common blocks may be of different sizes. */
399 if (!tree_int_cst_equal (DECL_SIZE_UNIT (decl
), size
)
400 && strcmp (com
->name
, BLANK_COMMON_NAME
))
401 gfc_warning (0, "Named COMMON block %qs at %L shall be of the "
402 "same size as elsewhere (%lu vs %lu bytes)", com
->name
,
404 (unsigned long) TREE_INT_CST_LOW (size
),
405 (unsigned long) TREE_INT_CST_LOW (DECL_SIZE_UNIT (decl
)));
407 if (tree_int_cst_lt (DECL_SIZE_UNIT (decl
), size
))
409 DECL_SIZE (decl
) = TYPE_SIZE (union_type
);
410 DECL_SIZE_UNIT (decl
) = size
;
411 SET_DECL_MODE (decl
, TYPE_MODE (union_type
));
412 TREE_TYPE (decl
) = union_type
;
413 layout_decl (decl
, 0);
417 /* If this common block has been declared in a previous program unit,
418 and either it is already initialized or there is no new initialization
419 for it, just return. */
420 if ((decl
!= NULL_TREE
) && (!is_init
|| DECL_INITIAL (decl
)))
423 /* If there is no backend_decl for the common block, build it. */
424 if (decl
== NULL_TREE
)
426 if (com
->is_bind_c
== 1 && com
->binding_label
)
427 decl
= build_decl (input_location
, VAR_DECL
, identifier
, union_type
);
430 decl
= build_decl (input_location
, VAR_DECL
, get_identifier (com
->name
),
432 gfc_set_decl_assembler_name (decl
, identifier
);
435 TREE_PUBLIC (decl
) = 1;
436 TREE_STATIC (decl
) = 1;
437 DECL_IGNORED_P (decl
) = 1;
439 SET_DECL_ALIGN (decl
, BIGGEST_ALIGNMENT
);
442 /* Do not set the alignment for bind(c) common blocks to
443 BIGGEST_ALIGNMENT because that won't match what C does. Also,
444 for common blocks with one element, the alignment must be
445 that of the field within the common block in order to match
447 tree field
= NULL_TREE
;
448 field
= TYPE_FIELDS (TREE_TYPE (decl
));
449 if (DECL_CHAIN (field
) == NULL_TREE
)
450 SET_DECL_ALIGN (decl
, TYPE_ALIGN (TREE_TYPE (field
)));
452 DECL_USER_ALIGN (decl
) = 0;
453 GFC_DECL_COMMON_OR_EQUIV (decl
) = 1;
455 gfc_set_decl_location (decl
, &com
->where
);
457 if (com
->threadprivate
)
458 set_decl_tls_model (decl
, decl_default_tls_model (decl
));
460 if (com
->omp_declare_target_link
)
461 DECL_ATTRIBUTES (decl
)
462 = tree_cons (get_identifier ("omp declare target link"),
463 NULL_TREE
, DECL_ATTRIBUTES (decl
));
464 else if (com
->omp_declare_target
)
465 DECL_ATTRIBUTES (decl
)
466 = tree_cons (get_identifier ("omp declare target"),
467 NULL_TREE
, DECL_ATTRIBUTES (decl
));
469 /* Place the back end declaration for this common block in
470 GLOBAL_BINDING_LEVEL. */
471 gfc_map_of_all_commons
[identifier
] = pushdecl_top_level (decl
);
474 /* Has no initial values. */
477 DECL_INITIAL (decl
) = NULL_TREE
;
478 DECL_COMMON (decl
) = 1;
479 DECL_DEFER_OUTPUT (decl
) = 1;
483 DECL_INITIAL (decl
) = error_mark_node
;
484 DECL_COMMON (decl
) = 0;
485 DECL_DEFER_OUTPUT (decl
) = 0;
491 /* Return a field that is the size of the union, if an equivalence has
492 overlapping initializers. Merge the initializers into a single
493 initializer for this new field, then free the old ones. */
496 get_init_field (segment_info
*head
, tree union_type
, tree
*field_init
,
497 record_layout_info rli
)
500 HOST_WIDE_INT length
= 0;
501 HOST_WIDE_INT offset
= 0;
502 unsigned HOST_WIDE_INT known_align
, desired_align
;
503 bool overlap
= false;
506 unsigned char *data
, *chk
;
507 vec
<constructor_elt
, va_gc
> *v
= NULL
;
509 tree type
= unsigned_char_type_node
;
512 /* Obtain the size of the union and check if there are any overlapping
514 for (s
= head
; s
; s
= s
->next
)
516 HOST_WIDE_INT slen
= s
->offset
+ s
->length
;
519 if (s
->offset
< offset
)
523 length
= length
< slen
? slen
: length
;
529 /* Now absorb all the initializer data into a single vector,
530 whilst checking for overlapping, unequal values. */
531 data
= XCNEWVEC (unsigned char, (size_t)length
);
532 chk
= XCNEWVEC (unsigned char, (size_t)length
);
534 /* TODO - change this when default initialization is implemented. */
535 memset (data
, '\0', (size_t)length
);
536 memset (chk
, '\0', (size_t)length
);
537 for (s
= head
; s
; s
= s
->next
)
541 if (s
->sym
->ns
->equiv
&& s
->sym
->ns
->equiv
->eq
)
542 loc
= &s
->sym
->ns
->equiv
->eq
->expr
->where
;
543 gfc_merge_initializers (s
->sym
->ts
, s
->sym
->value
, loc
,
549 for (i
= 0; i
< length
; i
++)
550 CONSTRUCTOR_APPEND_ELT (v
, NULL
, build_int_cst (type
, data
[i
]));
555 /* Build a char[length] array to hold the initializers. Much of what
556 follows is borrowed from build_field, above. */
558 tmp
= build_int_cst (gfc_array_index_type
, length
- 1);
559 tmp
= build_range_type (gfc_array_index_type
,
560 gfc_index_zero_node
, tmp
);
561 tmp
= build_array_type (type
, tmp
);
562 field
= build_decl (gfc_current_locus
.lb
->location
,
563 FIELD_DECL
, NULL_TREE
, tmp
);
565 known_align
= BIGGEST_ALIGNMENT
;
567 desired_align
= update_alignment_for_field (rli
, field
, known_align
);
568 if (desired_align
> known_align
)
569 DECL_PACKED (field
) = 1;
571 DECL_FIELD_CONTEXT (field
) = union_type
;
572 DECL_FIELD_OFFSET (field
) = size_int (0);
573 DECL_FIELD_BIT_OFFSET (field
) = bitsize_zero_node
;
574 SET_DECL_OFFSET_ALIGN (field
, known_align
);
576 rli
->offset
= size_binop (MAX_EXPR
, rli
->offset
,
577 size_binop (PLUS_EXPR
,
578 DECL_FIELD_OFFSET (field
),
579 DECL_SIZE_UNIT (field
)));
581 init
= build_constructor (TREE_TYPE (field
), v
);
582 TREE_CONSTANT (init
) = 1;
586 for (s
= head
; s
; s
= s
->next
)
588 if (s
->sym
->value
== NULL
)
591 gfc_free_expr (s
->sym
->value
);
592 s
->sym
->value
= NULL
;
599 /* Declare memory for the common block or local equivalence, and create
600 backend declarations for all of the elements. */
603 create_common (gfc_common_head
*com
, segment_info
*head
, bool saw_equiv
)
605 segment_info
*s
, *next_s
;
609 tree field_init
= NULL_TREE
;
610 record_layout_info rli
;
612 bool is_init
= false;
613 bool is_saved
= false;
614 bool is_auto
= false;
616 /* Declare the variables inside the common block.
617 If the current common block contains any equivalence object, then
618 make a UNION_TYPE node, otherwise RECORD_TYPE. This will let the
619 alias analyzer work well when there is no address overlapping for
620 common variables in the current common block. */
622 union_type
= make_node (UNION_TYPE
);
624 union_type
= make_node (RECORD_TYPE
);
626 rli
= start_record_layout (union_type
);
627 field_link
= &TYPE_FIELDS (union_type
);
629 /* Check for overlapping initializers and replace them with a single,
630 artificial field that contains all the data. */
632 field
= get_init_field (head
, union_type
, &field_init
, rli
);
636 if (field
!= NULL_TREE
)
640 field_link
= &DECL_CHAIN (field
);
643 for (s
= head
; s
; s
= s
->next
)
645 build_field (s
, union_type
, rli
);
647 /* Link the field into the type. */
648 *field_link
= s
->field
;
649 field_link
= &DECL_CHAIN (s
->field
);
651 /* Has initial value. */
655 /* Has SAVE attribute. */
656 if (s
->sym
->attr
.save
)
659 /* Has AUTOMATIC attribute. */
660 if (s
->sym
->attr
.automatic
)
664 finish_record_layout (rli
, true);
667 decl
= build_common_decl (com
, union_type
, is_init
);
669 decl
= build_equiv_decl (union_type
, is_init
, is_saved
, is_auto
);
674 vec
<constructor_elt
, va_gc
> *v
= NULL
;
676 if (field
!= NULL_TREE
&& field_init
!= NULL_TREE
)
677 CONSTRUCTOR_APPEND_ELT (v
, field
, field_init
);
679 for (s
= head
; s
; s
= s
->next
)
683 /* Add the initializer for this field. */
684 tmp
= gfc_conv_initializer (s
->sym
->value
, &s
->sym
->ts
,
685 TREE_TYPE (s
->field
),
686 s
->sym
->attr
.dimension
,
688 || s
->sym
->attr
.allocatable
, false);
690 CONSTRUCTOR_APPEND_ELT (v
, s
->field
, tmp
);
694 gcc_assert (!v
->is_empty ());
695 ctor
= build_constructor (union_type
, v
);
696 TREE_CONSTANT (ctor
) = 1;
697 TREE_STATIC (ctor
) = 1;
698 DECL_INITIAL (decl
) = ctor
;
703 unsigned HOST_WIDE_INT idx
;
704 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor
), idx
, field
, value
)
705 gcc_assert (TREE_CODE (field
) == FIELD_DECL
);
709 /* Build component reference for each variable. */
710 for (s
= head
; s
; s
= next_s
)
714 var_decl
= build_decl (s
->sym
->declared_at
.lb
->location
,
715 VAR_DECL
, DECL_NAME (s
->field
),
716 TREE_TYPE (s
->field
));
717 TREE_STATIC (var_decl
) = TREE_STATIC (decl
);
718 /* Mark the variable as used in order to avoid warnings about
720 TREE_USED (var_decl
) = 1;
721 if (s
->sym
->attr
.use_assoc
)
722 DECL_IGNORED_P (var_decl
) = 1;
723 if (s
->sym
->attr
.target
)
724 TREE_ADDRESSABLE (var_decl
) = 1;
725 /* Fake variables are not visible from other translation units. */
726 TREE_PUBLIC (var_decl
) = 0;
727 gfc_finish_decl_attrs (var_decl
, &s
->sym
->attr
);
729 /* To preserve identifier names in COMMON, chain to procedure
730 scope unless at top level in a module definition. */
732 && s
->sym
->ns
->proc_name
733 && s
->sym
->ns
->proc_name
->attr
.flavor
== FL_MODULE
)
734 var_decl
= pushdecl_top_level (var_decl
);
736 gfc_add_decl_to_function (var_decl
);
738 SET_DECL_VALUE_EXPR (var_decl
,
739 fold_build3_loc (input_location
, COMPONENT_REF
,
740 TREE_TYPE (s
->field
),
741 decl
, s
->field
, NULL_TREE
));
742 DECL_HAS_VALUE_EXPR_P (var_decl
) = 1;
743 GFC_DECL_COMMON_OR_EQUIV (var_decl
) = 1;
745 if (s
->sym
->attr
.assign
)
747 gfc_allocate_lang_decl (var_decl
);
748 GFC_DECL_ASSIGN (var_decl
) = 1;
749 GFC_DECL_STRING_LEN (var_decl
) = GFC_DECL_STRING_LEN (s
->field
);
750 GFC_DECL_ASSIGN_ADDR (var_decl
) = GFC_DECL_ASSIGN_ADDR (s
->field
);
753 s
->sym
->backend_decl
= var_decl
;
761 /* Given a symbol, find it in the current segment list. Returns NULL if
764 static segment_info
*
765 find_segment_info (gfc_symbol
*symbol
)
769 for (n
= current_segment
; n
; n
= n
->next
)
771 if (n
->sym
== symbol
)
779 /* Given an expression node, make sure it is a constant integer and return
783 get_mpz (gfc_expr
*e
)
786 if (e
->expr_type
!= EXPR_CONSTANT
)
787 gfc_internal_error ("get_mpz(): Not an integer constant");
789 return &e
->value
.integer
;
793 /* Given an array specification and an array reference, figure out the
794 array element number (zero based). Bounds and elements are guaranteed
795 to be constants. If something goes wrong we generate an error and
799 element_number (gfc_array_ref
*ar
)
801 mpz_t multiplier
, offset
, extent
, n
;
803 HOST_WIDE_INT i
, rank
;
807 mpz_init_set_ui (multiplier
, 1);
808 mpz_init_set_ui (offset
, 0);
812 for (i
= 0; i
< rank
; i
++)
814 if (ar
->dimen_type
[i
] != DIMEN_ELEMENT
)
815 gfc_internal_error ("element_number(): Bad dimension type");
817 if (as
&& as
->lower
[i
])
818 mpz_sub (n
, *get_mpz (ar
->start
[i
]), *get_mpz (as
->lower
[i
]));
820 mpz_sub_ui (n
, *get_mpz (ar
->start
[i
]), 1);
822 mpz_mul (n
, n
, multiplier
);
823 mpz_add (offset
, offset
, n
);
825 if (as
&& as
->upper
[i
] && as
->lower
[i
])
827 mpz_sub (extent
, *get_mpz (as
->upper
[i
]), *get_mpz (as
->lower
[i
]));
828 mpz_add_ui (extent
, extent
, 1);
831 mpz_set_ui (extent
, 0);
833 if (mpz_sgn (extent
) < 0)
834 mpz_set_ui (extent
, 0);
836 mpz_mul (multiplier
, multiplier
, extent
);
839 i
= mpz_get_ui (offset
);
841 mpz_clear (multiplier
);
850 /* Given a single element of an equivalence list, figure out the offset
851 from the base symbol. For simple variables or full arrays, this is
852 simply zero. For an array element we have to calculate the array
853 element number and multiply by the element size. For a substring we
854 have to calculate the further reference. */
857 calculate_offset (gfc_expr
*e
)
859 HOST_WIDE_INT n
, element_size
, offset
;
860 gfc_typespec
*element_type
;
864 element_type
= &e
->symtree
->n
.sym
->ts
;
866 for (reference
= e
->ref
; reference
; reference
= reference
->next
)
867 switch (reference
->type
)
870 switch (reference
->u
.ar
.type
)
876 n
= element_number (&reference
->u
.ar
);
877 if (element_type
->type
== BT_CHARACTER
)
878 gfc_conv_const_charlen (element_type
->u
.cl
);
880 int_size_in_bytes (gfc_typenode_for_spec (element_type
));
881 offset
+= n
* element_size
;
885 gfc_error ("Bad array reference at %L", &e
->where
);
889 if (reference
->u
.ss
.start
!= NULL
)
890 offset
+= mpz_get_ui (*get_mpz (reference
->u
.ss
.start
)) - 1;
893 gfc_error ("Illegal reference type at %L as EQUIVALENCE object",
900 /* Add a new segment_info structure to the current segment. eq1 is already
901 in the list, eq2 is not. */
904 new_condition (segment_info
*v
, gfc_equiv
*eq1
, gfc_equiv
*eq2
)
906 HOST_WIDE_INT offset1
, offset2
;
909 offset1
= calculate_offset (eq1
->expr
);
910 offset2
= calculate_offset (eq2
->expr
);
912 a
= get_segment_info (eq2
->expr
->symtree
->n
.sym
,
913 v
->offset
+ offset1
- offset2
);
915 current_segment
= add_segments (current_segment
, a
);
919 /* Given two equivalence structures that are both already in the list, make
920 sure that this new condition is not violated, generating an error if it
924 confirm_condition (segment_info
*s1
, gfc_equiv
*eq1
, segment_info
*s2
,
927 HOST_WIDE_INT offset1
, offset2
;
929 offset1
= calculate_offset (eq1
->expr
);
930 offset2
= calculate_offset (eq2
->expr
);
932 if (s1
->offset
+ offset1
!= s2
->offset
+ offset2
)
933 gfc_error ("Inconsistent equivalence rules involving %qs at %L and "
934 "%qs at %L", s1
->sym
->name
, &s1
->sym
->declared_at
,
935 s2
->sym
->name
, &s2
->sym
->declared_at
);
939 /* Process a new equivalence condition. eq1 is know to be in segment f.
940 If eq2 is also present then confirm that the condition holds.
941 Otherwise add a new variable to the segment list. */
944 add_condition (segment_info
*f
, gfc_equiv
*eq1
, gfc_equiv
*eq2
)
948 n
= find_segment_info (eq2
->expr
->symtree
->n
.sym
);
951 new_condition (f
, eq1
, eq2
);
953 confirm_condition (f
, eq1
, n
, eq2
);
957 accumulate_equivalence_attributes (symbol_attribute
*dummy_symbol
, gfc_equiv
*e
)
959 symbol_attribute attr
= e
->expr
->symtree
->n
.sym
->attr
;
961 dummy_symbol
->dummy
|= attr
.dummy
;
962 dummy_symbol
->pointer
|= attr
.pointer
;
963 dummy_symbol
->target
|= attr
.target
;
964 dummy_symbol
->external
|= attr
.external
;
965 dummy_symbol
->intrinsic
|= attr
.intrinsic
;
966 dummy_symbol
->allocatable
|= attr
.allocatable
;
967 dummy_symbol
->elemental
|= attr
.elemental
;
968 dummy_symbol
->recursive
|= attr
.recursive
;
969 dummy_symbol
->in_common
|= attr
.in_common
;
970 dummy_symbol
->result
|= attr
.result
;
971 dummy_symbol
->in_namelist
|= attr
.in_namelist
;
972 dummy_symbol
->optional
|= attr
.optional
;
973 dummy_symbol
->entry
|= attr
.entry
;
974 dummy_symbol
->function
|= attr
.function
;
975 dummy_symbol
->subroutine
|= attr
.subroutine
;
976 dummy_symbol
->dimension
|= attr
.dimension
;
977 dummy_symbol
->in_equivalence
|= attr
.in_equivalence
;
978 dummy_symbol
->use_assoc
|= attr
.use_assoc
;
979 dummy_symbol
->cray_pointer
|= attr
.cray_pointer
;
980 dummy_symbol
->cray_pointee
|= attr
.cray_pointee
;
981 dummy_symbol
->data
|= attr
.data
;
982 dummy_symbol
->value
|= attr
.value
;
983 dummy_symbol
->volatile_
|= attr
.volatile_
;
984 dummy_symbol
->is_protected
|= attr
.is_protected
;
985 dummy_symbol
->is_bind_c
|= attr
.is_bind_c
;
986 dummy_symbol
->procedure
|= attr
.procedure
;
987 dummy_symbol
->proc_pointer
|= attr
.proc_pointer
;
988 dummy_symbol
->abstract
|= attr
.abstract
;
989 dummy_symbol
->asynchronous
|= attr
.asynchronous
;
990 dummy_symbol
->codimension
|= attr
.codimension
;
991 dummy_symbol
->contiguous
|= attr
.contiguous
;
992 dummy_symbol
->generic
|= attr
.generic
;
993 dummy_symbol
->automatic
|= attr
.automatic
;
994 dummy_symbol
->threadprivate
|= attr
.threadprivate
;
995 dummy_symbol
->omp_declare_target
|= attr
.omp_declare_target
;
996 dummy_symbol
->omp_declare_target_link
|= attr
.omp_declare_target_link
;
997 dummy_symbol
->oacc_declare_copyin
|= attr
.oacc_declare_copyin
;
998 dummy_symbol
->oacc_declare_create
|= attr
.oacc_declare_create
;
999 dummy_symbol
->oacc_declare_deviceptr
|= attr
.oacc_declare_deviceptr
;
1000 dummy_symbol
->oacc_declare_device_resident
1001 |= attr
.oacc_declare_device_resident
;
1003 /* Not strictly correct, but probably close enough. */
1004 if (attr
.save
> dummy_symbol
->save
)
1005 dummy_symbol
->save
= attr
.save
;
1006 if (attr
.access
> dummy_symbol
->access
)
1007 dummy_symbol
->access
= attr
.access
;
1010 /* Given a segment element, search through the equivalence lists for unused
1011 conditions that involve the symbol. Add these rules to the segment. */
1014 find_equivalence (segment_info
*n
)
1016 gfc_equiv
*e1
, *e2
, *eq
;
1021 for (e1
= n
->sym
->ns
->equiv
; e1
; e1
= e1
->next
)
1025 /* Search the equivalence list, including the root (first) element
1026 for the symbol that owns the segment. */
1027 symbol_attribute dummy_symbol
;
1028 memset (&dummy_symbol
, 0, sizeof (dummy_symbol
));
1029 for (e2
= e1
; e2
; e2
= e2
->eq
)
1031 accumulate_equivalence_attributes (&dummy_symbol
, e2
);
1032 if (!e2
->used
&& e2
->expr
->symtree
->n
.sym
== n
->sym
)
1039 gfc_check_conflict (&dummy_symbol
, e1
->expr
->symtree
->name
, &e1
->expr
->where
);
1041 /* Go to the next root element. */
1047 /* Now traverse the equivalence list matching the offsets. */
1048 for (e2
= e1
; e2
; e2
= e2
->eq
)
1050 if (!e2
->used
&& e2
!= eq
)
1052 add_condition (n
, eq
, e2
);
1062 /* Add all symbols equivalenced within a segment. We need to scan the
1063 segment list multiple times to include indirect equivalences. Since
1064 a new segment_info can inserted at the beginning of the segment list,
1065 depending on its offset, we have to force a final pass through the
1066 loop by demanding that completion sees a pass with no matches; i.e.,
1067 all symbols with equiv_built set and no new equivalences found. */
1070 add_equivalences (bool *saw_equiv
)
1078 for (f
= current_segment
; f
; f
= f
->next
)
1080 if (!f
->sym
->equiv_built
)
1082 f
->sym
->equiv_built
= 1;
1083 bool seen_one
= find_equivalence (f
);
1093 /* Add a copy of this segment list to the namespace. */
1094 copy_equiv_list_to_ns (current_segment
);
1098 /* Returns the offset necessary to properly align the current equivalence.
1099 Sets *palign to the required alignment. */
1101 static HOST_WIDE_INT
1102 align_segment (unsigned HOST_WIDE_INT
*palign
)
1105 unsigned HOST_WIDE_INT offset
;
1106 unsigned HOST_WIDE_INT max_align
;
1107 unsigned HOST_WIDE_INT this_align
;
1108 unsigned HOST_WIDE_INT this_offset
;
1112 for (s
= current_segment
; s
; s
= s
->next
)
1114 this_align
= TYPE_ALIGN_UNIT (s
->field
);
1115 if (s
->offset
& (this_align
- 1))
1117 /* Field is misaligned. */
1118 this_offset
= this_align
- ((s
->offset
+ offset
) & (this_align
- 1));
1119 if (this_offset
& (max_align
- 1))
1121 /* Aligning this field would misalign a previous field. */
1122 gfc_error ("The equivalence set for variable %qs "
1123 "declared at %L violates alignment requirements",
1124 s
->sym
->name
, &s
->sym
->declared_at
);
1126 offset
+= this_offset
;
1128 max_align
= this_align
;
1131 *palign
= max_align
;
1136 /* Adjust segment offsets by the given amount. */
1139 apply_segment_offset (segment_info
*s
, HOST_WIDE_INT offset
)
1141 for (; s
; s
= s
->next
)
1142 s
->offset
+= offset
;
1146 /* Lay out a symbol in a common block. If the symbol has already been seen
1147 then check the location is consistent. Otherwise create segments
1148 for that symbol and all the symbols equivalenced with it. */
1150 /* Translate a single common block. */
1153 translate_common (gfc_common_head
*common
, gfc_symbol
*var_list
)
1157 segment_info
*common_segment
;
1158 HOST_WIDE_INT offset
;
1159 HOST_WIDE_INT current_offset
;
1160 unsigned HOST_WIDE_INT align
;
1163 common_segment
= NULL
;
1169 /* Add symbols to the segment. */
1170 for (sym
= var_list
; sym
; sym
= sym
->common_next
)
1172 current_segment
= common_segment
;
1173 s
= find_segment_info (sym
);
1175 /* Symbol has already been added via an equivalence. Multiple
1176 use associations of the same common block result in equiv_built
1177 being set but no information about the symbol in the segment. */
1178 if (s
&& sym
->equiv_built
)
1180 /* Ensure the current location is properly aligned. */
1181 align
= TYPE_ALIGN_UNIT (s
->field
);
1182 current_offset
= (current_offset
+ align
- 1) &~ (align
- 1);
1184 /* Verify that it ended up where we expect it. */
1185 if (s
->offset
!= current_offset
)
1187 gfc_error ("Equivalence for %qs does not match ordering of "
1188 "COMMON %qs at %L", sym
->name
,
1189 common
->name
, &common
->where
);
1194 /* A symbol we haven't seen before. */
1195 s
= current_segment
= get_segment_info (sym
, current_offset
);
1197 /* Add all objects directly or indirectly equivalenced with this
1199 add_equivalences (&saw_equiv
);
1201 if (current_segment
->offset
< 0)
1202 gfc_error ("The equivalence set for %qs cause an invalid "
1203 "extension to COMMON %qs at %L", sym
->name
,
1204 common
->name
, &common
->where
);
1206 if (flag_align_commons
)
1207 offset
= align_segment (&align
);
1211 /* The required offset conflicts with previous alignment
1212 requirements. Insert padding immediately before this
1214 if (warn_align_commons
)
1216 if (strcmp (common
->name
, BLANK_COMMON_NAME
))
1217 gfc_warning (OPT_Walign_commons
,
1218 "Padding of %d bytes required before %qs in "
1219 "COMMON %qs at %L; reorder elements or use "
1220 "%<-fno-align-commons%>", (int)offset
,
1221 s
->sym
->name
, common
->name
, &common
->where
);
1223 gfc_warning (OPT_Walign_commons
,
1224 "Padding of %d bytes required before %qs in "
1225 "COMMON at %L; reorder elements or use "
1226 "%<-fno-align-commons%>", (int)offset
,
1227 s
->sym
->name
, &common
->where
);
1231 /* Apply the offset to the new segments. */
1232 apply_segment_offset (current_segment
, offset
);
1233 current_offset
+= offset
;
1235 /* Add the new segments to the common block. */
1236 common_segment
= add_segments (common_segment
, current_segment
);
1239 /* The offset of the next common variable. */
1240 current_offset
+= s
->length
;
1243 if (common_segment
== NULL
)
1245 gfc_error ("COMMON %qs at %L does not exist",
1246 common
->name
, &common
->where
);
1250 if (common_segment
->offset
!= 0 && warn_align_commons
)
1252 if (strcmp (common
->name
, BLANK_COMMON_NAME
))
1253 gfc_warning (OPT_Walign_commons
,
1254 "COMMON %qs at %L requires %d bytes of padding; "
1255 "reorder elements or use %<-fno-align-commons%>",
1256 common
->name
, &common
->where
, (int)common_segment
->offset
);
1258 gfc_warning (OPT_Walign_commons
,
1259 "COMMON at %L requires %d bytes of padding; "
1260 "reorder elements or use %<-fno-align-commons%>",
1261 &common
->where
, (int)common_segment
->offset
);
1264 create_common (common
, common_segment
, saw_equiv
);
1268 /* Create a new block for each merged equivalence list. */
1271 finish_equivalences (gfc_namespace
*ns
)
1275 gfc_common_head
* c
;
1276 HOST_WIDE_INT offset
;
1277 unsigned HOST_WIDE_INT align
;
1280 for (z
= ns
->equiv
; z
; z
= z
->next
)
1281 for (y
= z
->eq
; y
; y
= y
->eq
)
1285 sym
= z
->expr
->symtree
->n
.sym
;
1286 current_segment
= get_segment_info (sym
, 0);
1288 /* All objects directly or indirectly equivalenced with this
1290 add_equivalences (&dummy
);
1292 /* Align the block. */
1293 offset
= align_segment (&align
);
1295 /* Ensure all offsets are positive. */
1296 offset
-= current_segment
->offset
& ~(align
- 1);
1298 apply_segment_offset (current_segment
, offset
);
1300 /* Create the decl. If this is a module equivalence, it has a
1301 unique name, pointed to by z->module. This is written to a
1302 gfc_common_header to push create_common into using
1303 build_common_decl, so that the equivalence appears as an
1304 external symbol. Otherwise, a local declaration is built using
1305 build_equiv_decl. */
1308 c
= gfc_get_common_head ();
1309 /* We've lost the real location, so use the location of the
1310 enclosing procedure. If we're in a BLOCK DATA block, then
1311 use the location in the sym_root. */
1313 c
->where
= ns
->proc_name
->declared_at
;
1314 else if (ns
->is_block_data
)
1315 c
->where
= ns
->sym_root
->n
.sym
->declared_at
;
1316 strcpy (c
->name
, z
->module
);
1321 create_common (c
, current_segment
, true);
1327 /* Work function for translating a named common block. */
1330 named_common (gfc_symtree
*st
)
1332 translate_common (st
->n
.common
, st
->n
.common
->head
);
1336 /* Translate the common blocks in a namespace. Unlike other variables,
1337 these have to be created before code, because the backend_decl depends
1338 on the rest of the common block. */
1341 gfc_trans_common (gfc_namespace
*ns
)
1345 /* Translate the blank common block. */
1346 if (ns
->blank_common
.head
!= NULL
)
1348 c
= gfc_get_common_head ();
1349 c
->where
= ns
->blank_common
.head
->common_head
->where
;
1350 strcpy (c
->name
, BLANK_COMMON_NAME
);
1351 translate_common (c
, ns
->blank_common
.head
);
1354 /* Translate all named common blocks. */
1355 gfc_traverse_symtree (ns
->common_root
, named_common
);
1357 /* Translate local equivalence. */
1358 finish_equivalences (ns
);
1360 /* Commit the newly created symbols for common blocks and module
1362 gfc_commit_symbols ();