1 /* Routines for manipulation of expression nodes.
2 Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006 Free Software
4 Contributed by Andy Vaught
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 2, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to the Free
20 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
29 /* Get a new expr node. */
36 e
= gfc_getmem (sizeof (gfc_expr
));
38 gfc_clear_ts (&e
->ts
);
47 /* Free an argument list and everything below it. */
50 gfc_free_actual_arglist (gfc_actual_arglist
* a1
)
52 gfc_actual_arglist
*a2
;
57 gfc_free_expr (a1
->expr
);
64 /* Copy an arglist structure and all of the arguments. */
67 gfc_copy_actual_arglist (gfc_actual_arglist
* p
)
69 gfc_actual_arglist
*head
, *tail
, *new;
73 for (; p
; p
= p
->next
)
75 new = gfc_get_actual_arglist ();
78 new->expr
= gfc_copy_expr (p
->expr
);
93 /* Free a list of reference structures. */
96 gfc_free_ref_list (gfc_ref
* p
)
108 for (i
= 0; i
< GFC_MAX_DIMENSIONS
; i
++)
110 gfc_free_expr (p
->u
.ar
.start
[i
]);
111 gfc_free_expr (p
->u
.ar
.end
[i
]);
112 gfc_free_expr (p
->u
.ar
.stride
[i
]);
118 gfc_free_expr (p
->u
.ss
.start
);
119 gfc_free_expr (p
->u
.ss
.end
);
131 /* Workhorse function for gfc_free_expr() that frees everything
132 beneath an expression node, but not the node itself. This is
133 useful when we want to simplify a node and replace it with
134 something else or the expression node belongs to another structure. */
137 free_expr0 (gfc_expr
* e
)
141 switch (e
->expr_type
)
146 gfc_free (e
->value
.character
.string
);
153 mpz_clear (e
->value
.integer
);
157 mpfr_clear (e
->value
.real
);
162 gfc_free (e
->value
.character
.string
);
166 mpfr_clear (e
->value
.complex.r
);
167 mpfr_clear (e
->value
.complex.i
);
177 if (e
->value
.op
.op1
!= NULL
)
178 gfc_free_expr (e
->value
.op
.op1
);
179 if (e
->value
.op
.op2
!= NULL
)
180 gfc_free_expr (e
->value
.op
.op2
);
184 gfc_free_actual_arglist (e
->value
.function
.actual
);
192 gfc_free_constructor (e
->value
.constructor
);
196 gfc_free (e
->value
.character
.string
);
203 gfc_internal_error ("free_expr0(): Bad expr type");
206 /* Free a shape array. */
207 if (e
->shape
!= NULL
)
209 for (n
= 0; n
< e
->rank
; n
++)
210 mpz_clear (e
->shape
[n
]);
215 gfc_free_ref_list (e
->ref
);
217 memset (e
, '\0', sizeof (gfc_expr
));
221 /* Free an expression node and everything beneath it. */
224 gfc_free_expr (gfc_expr
* e
)
235 /* Graft the *src expression onto the *dest subexpression. */
238 gfc_replace_expr (gfc_expr
* dest
, gfc_expr
* src
)
248 /* Try to extract an integer constant from the passed expression node.
249 Returns an error message or NULL if the result is set. It is
250 tempting to generate an error and return SUCCESS or FAILURE, but
251 failure is OK for some callers. */
254 gfc_extract_int (gfc_expr
* expr
, int *result
)
257 if (expr
->expr_type
!= EXPR_CONSTANT
)
258 return _("Constant expression required at %C");
260 if (expr
->ts
.type
!= BT_INTEGER
)
261 return _("Integer expression required at %C");
263 if ((mpz_cmp_si (expr
->value
.integer
, INT_MAX
) > 0)
264 || (mpz_cmp_si (expr
->value
.integer
, INT_MIN
) < 0))
266 return _("Integer value too large in expression at %C");
269 *result
= (int) mpz_get_si (expr
->value
.integer
);
275 /* Recursively copy a list of reference structures. */
278 copy_ref (gfc_ref
* src
)
286 dest
= gfc_get_ref ();
287 dest
->type
= src
->type
;
292 ar
= gfc_copy_array_ref (&src
->u
.ar
);
298 dest
->u
.c
= src
->u
.c
;
302 dest
->u
.ss
= src
->u
.ss
;
303 dest
->u
.ss
.start
= gfc_copy_expr (src
->u
.ss
.start
);
304 dest
->u
.ss
.end
= gfc_copy_expr (src
->u
.ss
.end
);
308 dest
->next
= copy_ref (src
->next
);
314 /* Detect whether an expression has any vector index array
318 gfc_has_vector_index (gfc_expr
*e
)
322 for (ref
= e
->ref
; ref
; ref
= ref
->next
)
323 if (ref
->type
== REF_ARRAY
)
324 for (i
= 0; i
< ref
->u
.ar
.dimen
; i
++)
325 if (ref
->u
.ar
.dimen_type
[i
] == DIMEN_VECTOR
)
331 /* Copy a shape array. */
334 gfc_copy_shape (mpz_t
* shape
, int rank
)
342 new_shape
= gfc_get_shape (rank
);
344 for (n
= 0; n
< rank
; n
++)
345 mpz_init_set (new_shape
[n
], shape
[n
]);
351 /* Copy a shape array excluding dimension N, where N is an integer
352 constant expression. Dimensions are numbered in fortran style --
355 So, if the original shape array contains R elements
356 { s1 ... sN-1 sN sN+1 ... sR-1 sR}
357 the result contains R-1 elements:
358 { s1 ... sN-1 sN+1 ... sR-1}
360 If anything goes wrong -- N is not a constant, its value is out
361 of range -- or anything else, just returns NULL.
365 gfc_copy_shape_excluding (mpz_t
* shape
, int rank
, gfc_expr
* dim
)
367 mpz_t
*new_shape
, *s
;
373 || dim
->expr_type
!= EXPR_CONSTANT
374 || dim
->ts
.type
!= BT_INTEGER
)
377 n
= mpz_get_si (dim
->value
.integer
);
378 n
--; /* Convert to zero based index */
379 if (n
< 0 || n
>= rank
)
382 s
= new_shape
= gfc_get_shape (rank
-1);
384 for (i
= 0; i
< rank
; i
++)
388 mpz_init_set (*s
, shape
[i
]);
395 /* Given an expression pointer, return a copy of the expression. This
396 subroutine is recursive. */
399 gfc_copy_expr (gfc_expr
* p
)
410 switch (q
->expr_type
)
413 s
= gfc_getmem (p
->value
.character
.length
+ 1);
414 q
->value
.character
.string
= s
;
416 memcpy (s
, p
->value
.character
.string
, p
->value
.character
.length
+ 1);
422 s
= gfc_getmem (p
->value
.character
.length
+ 1);
423 q
->value
.character
.string
= s
;
425 memcpy (s
, p
->value
.character
.string
,
426 p
->value
.character
.length
+ 1);
432 mpz_init_set (q
->value
.integer
, p
->value
.integer
);
436 gfc_set_model_kind (q
->ts
.kind
);
437 mpfr_init (q
->value
.real
);
438 mpfr_set (q
->value
.real
, p
->value
.real
, GFC_RND_MODE
);
442 gfc_set_model_kind (q
->ts
.kind
);
443 mpfr_init (q
->value
.complex.r
);
444 mpfr_init (q
->value
.complex.i
);
445 mpfr_set (q
->value
.complex.r
, p
->value
.complex.r
, GFC_RND_MODE
);
446 mpfr_set (q
->value
.complex.i
, p
->value
.complex.i
, GFC_RND_MODE
);
451 s
= gfc_getmem (p
->value
.character
.length
+ 1);
452 q
->value
.character
.string
= s
;
454 memcpy (s
, p
->value
.character
.string
,
455 p
->value
.character
.length
+ 1);
460 break; /* Already done */
464 gfc_internal_error ("gfc_copy_expr(): Bad expr node");
471 switch (q
->value
.op
.operator)
474 case INTRINSIC_UPLUS
:
475 case INTRINSIC_UMINUS
:
476 q
->value
.op
.op1
= gfc_copy_expr (p
->value
.op
.op1
);
479 default: /* Binary operators */
480 q
->value
.op
.op1
= gfc_copy_expr (p
->value
.op
.op1
);
481 q
->value
.op
.op2
= gfc_copy_expr (p
->value
.op
.op2
);
488 q
->value
.function
.actual
=
489 gfc_copy_actual_arglist (p
->value
.function
.actual
);
494 q
->value
.constructor
= gfc_copy_constructor (p
->value
.constructor
);
502 q
->shape
= gfc_copy_shape (p
->shape
, p
->rank
);
504 q
->ref
= copy_ref (p
->ref
);
510 /* Return the maximum kind of two expressions. In general, higher
511 kind numbers mean more precision for numeric types. */
514 gfc_kind_max (gfc_expr
* e1
, gfc_expr
* e2
)
517 return (e1
->ts
.kind
> e2
->ts
.kind
) ? e1
->ts
.kind
: e2
->ts
.kind
;
521 /* Returns nonzero if the type is numeric, zero otherwise. */
524 numeric_type (bt type
)
527 return type
== BT_COMPLEX
|| type
== BT_REAL
|| type
== BT_INTEGER
;
531 /* Returns nonzero if the typespec is a numeric type, zero otherwise. */
534 gfc_numeric_ts (gfc_typespec
* ts
)
537 return numeric_type (ts
->type
);
541 /* Returns an expression node that is an integer constant. */
550 p
->expr_type
= EXPR_CONSTANT
;
551 p
->ts
.type
= BT_INTEGER
;
552 p
->ts
.kind
= gfc_default_integer_kind
;
554 p
->where
= gfc_current_locus
;
555 mpz_init_set_si (p
->value
.integer
, i
);
561 /* Returns an expression node that is a logical constant. */
564 gfc_logical_expr (int i
, locus
* where
)
570 p
->expr_type
= EXPR_CONSTANT
;
571 p
->ts
.type
= BT_LOGICAL
;
572 p
->ts
.kind
= gfc_default_logical_kind
;
575 where
= &gfc_current_locus
;
577 p
->value
.logical
= i
;
583 /* Return an expression node with an optional argument list attached.
584 A variable number of gfc_expr pointers are strung together in an
585 argument list with a NULL pointer terminating the list. */
588 gfc_build_conversion (gfc_expr
* e
)
593 p
->expr_type
= EXPR_FUNCTION
;
595 p
->value
.function
.actual
= NULL
;
597 p
->value
.function
.actual
= gfc_get_actual_arglist ();
598 p
->value
.function
.actual
->expr
= e
;
604 /* Given an expression node with some sort of numeric binary
605 expression, insert type conversions required to make the operands
608 The exception is that the operands of an exponential don't have to
609 have the same type. If possible, the base is promoted to the type
610 of the exponent. For example, 1**2.3 becomes 1.0**2.3, but
611 1.0**2 stays as it is. */
614 gfc_type_convert_binary (gfc_expr
* e
)
618 op1
= e
->value
.op
.op1
;
619 op2
= e
->value
.op
.op2
;
621 if (op1
->ts
.type
== BT_UNKNOWN
|| op2
->ts
.type
== BT_UNKNOWN
)
623 gfc_clear_ts (&e
->ts
);
627 /* Kind conversions of same type. */
628 if (op1
->ts
.type
== op2
->ts
.type
)
631 if (op1
->ts
.kind
== op2
->ts
.kind
)
633 /* No type conversions. */
638 if (op1
->ts
.kind
> op2
->ts
.kind
)
639 gfc_convert_type (op2
, &op1
->ts
, 2);
641 gfc_convert_type (op1
, &op2
->ts
, 2);
647 /* Integer combined with real or complex. */
648 if (op2
->ts
.type
== BT_INTEGER
)
652 /* Special case for ** operator. */
653 if (e
->value
.op
.operator == INTRINSIC_POWER
)
656 gfc_convert_type (e
->value
.op
.op2
, &e
->ts
, 2);
660 if (op1
->ts
.type
== BT_INTEGER
)
663 gfc_convert_type (e
->value
.op
.op1
, &e
->ts
, 2);
667 /* Real combined with complex. */
668 e
->ts
.type
= BT_COMPLEX
;
669 if (op1
->ts
.kind
> op2
->ts
.kind
)
670 e
->ts
.kind
= op1
->ts
.kind
;
672 e
->ts
.kind
= op2
->ts
.kind
;
673 if (op1
->ts
.type
!= BT_COMPLEX
|| op1
->ts
.kind
!= e
->ts
.kind
)
674 gfc_convert_type (e
->value
.op
.op1
, &e
->ts
, 2);
675 if (op2
->ts
.type
!= BT_COMPLEX
|| op2
->ts
.kind
!= e
->ts
.kind
)
676 gfc_convert_type (e
->value
.op
.op2
, &e
->ts
, 2);
683 /* Function to determine if an expression is constant or not. This
684 function expects that the expression has already been simplified. */
687 gfc_is_constant_expr (gfc_expr
* e
)
690 gfc_actual_arglist
*arg
;
696 switch (e
->expr_type
)
699 rv
= (gfc_is_constant_expr (e
->value
.op
.op1
)
700 && (e
->value
.op
.op2
== NULL
701 || gfc_is_constant_expr (e
->value
.op
.op2
)));
710 /* Call to intrinsic with at least one argument. */
712 if (e
->value
.function
.isym
&& e
->value
.function
.actual
)
714 for (arg
= e
->value
.function
.actual
; arg
; arg
= arg
->next
)
716 if (!gfc_is_constant_expr (arg
->expr
))
730 rv
= (gfc_is_constant_expr (e
->ref
->u
.ss
.start
)
731 && gfc_is_constant_expr (e
->ref
->u
.ss
.end
));
736 for (c
= e
->value
.constructor
; c
; c
= c
->next
)
737 if (!gfc_is_constant_expr (c
->expr
))
745 rv
= gfc_constant_ac (e
);
749 gfc_internal_error ("gfc_is_constant_expr(): Unknown expression type");
756 /* Try to collapse intrinsic expressions. */
759 simplify_intrinsic_op (gfc_expr
* p
, int type
)
761 gfc_expr
*op1
, *op2
, *result
;
763 if (p
->value
.op
.operator == INTRINSIC_USER
)
766 op1
= p
->value
.op
.op1
;
767 op2
= p
->value
.op
.op2
;
769 if (gfc_simplify_expr (op1
, type
) == FAILURE
)
771 if (gfc_simplify_expr (op2
, type
) == FAILURE
)
774 if (!gfc_is_constant_expr (op1
)
775 || (op2
!= NULL
&& !gfc_is_constant_expr (op2
)))
779 p
->value
.op
.op1
= NULL
;
780 p
->value
.op
.op2
= NULL
;
782 switch (p
->value
.op
.operator)
784 case INTRINSIC_UPLUS
:
785 case INTRINSIC_PARENTHESES
:
786 result
= gfc_uplus (op1
);
789 case INTRINSIC_UMINUS
:
790 result
= gfc_uminus (op1
);
794 result
= gfc_add (op1
, op2
);
797 case INTRINSIC_MINUS
:
798 result
= gfc_subtract (op1
, op2
);
801 case INTRINSIC_TIMES
:
802 result
= gfc_multiply (op1
, op2
);
805 case INTRINSIC_DIVIDE
:
806 result
= gfc_divide (op1
, op2
);
809 case INTRINSIC_POWER
:
810 result
= gfc_power (op1
, op2
);
813 case INTRINSIC_CONCAT
:
814 result
= gfc_concat (op1
, op2
);
818 result
= gfc_eq (op1
, op2
);
822 result
= gfc_ne (op1
, op2
);
826 result
= gfc_gt (op1
, op2
);
830 result
= gfc_ge (op1
, op2
);
834 result
= gfc_lt (op1
, op2
);
838 result
= gfc_le (op1
, op2
);
842 result
= gfc_not (op1
);
846 result
= gfc_and (op1
, op2
);
850 result
= gfc_or (op1
, op2
);
854 result
= gfc_eqv (op1
, op2
);
858 result
= gfc_neqv (op1
, op2
);
862 gfc_internal_error ("simplify_intrinsic_op(): Bad operator");
872 gfc_replace_expr (p
, result
);
878 /* Subroutine to simplify constructor expressions. Mutually recursive
879 with gfc_simplify_expr(). */
882 simplify_constructor (gfc_constructor
* c
, int type
)
885 for (; c
; c
= c
->next
)
888 && (gfc_simplify_expr (c
->iterator
->start
, type
) == FAILURE
889 || gfc_simplify_expr (c
->iterator
->end
, type
) == FAILURE
890 || gfc_simplify_expr (c
->iterator
->step
, type
) == FAILURE
))
893 if (c
->expr
&& gfc_simplify_expr (c
->expr
, type
) == FAILURE
)
901 /* Pull a single array element out of an array constructor. */
903 static gfc_constructor
*
904 find_array_element (gfc_constructor
* cons
, gfc_array_ref
* ar
)
906 unsigned long nelemen
;
911 mpz_init_set_ui (offset
, 0);
913 for (i
= 0; i
< ar
->dimen
; i
++)
915 if (ar
->start
[i
]->expr_type
!= EXPR_CONSTANT
)
920 mpz_sub (delta
, ar
->start
[i
]->value
.integer
,
921 ar
->as
->lower
[i
]->value
.integer
);
922 mpz_add (offset
, offset
, delta
);
927 if (mpz_fits_ulong_p (offset
))
929 for (nelemen
= mpz_get_ui (offset
); nelemen
> 0; nelemen
--)
950 /* Find a component of a structure constructor. */
952 static gfc_constructor
*
953 find_component_ref (gfc_constructor
* cons
, gfc_ref
* ref
)
958 comp
= ref
->u
.c
.sym
->components
;
959 pick
= ref
->u
.c
.component
;
970 /* Replace an expression with the contents of a constructor, removing
971 the subobject reference in the process. */
974 remove_subobject_ref (gfc_expr
* p
, gfc_constructor
* cons
)
980 e
->ref
= p
->ref
->next
;
982 gfc_replace_expr (p
, e
);
986 /* Simplify a subobject reference of a constructor. This occurs when
987 parameter variable values are substituted. */
990 simplify_const_ref (gfc_expr
* p
)
992 gfc_constructor
*cons
;
996 switch (p
->ref
->type
)
999 switch (p
->ref
->u
.ar
.type
)
1002 cons
= find_array_element (p
->value
.constructor
, &p
->ref
->u
.ar
);
1005 remove_subobject_ref (p
, cons
);
1009 if (p
->ref
->next
!= NULL
)
1011 /* TODO: Simplify array subobject references. */
1014 gfc_free_ref_list (p
->ref
);
1019 /* TODO: Simplify array subsections. */
1026 cons
= find_component_ref (p
->value
.constructor
, p
->ref
);
1027 remove_subobject_ref (p
, cons
);
1031 /* TODO: Constant substrings. */
1040 /* Simplify a chain of references. */
1043 simplify_ref_chain (gfc_ref
* ref
, int type
)
1047 for (; ref
; ref
= ref
->next
)
1052 for (n
= 0; n
< ref
->u
.ar
.dimen
; n
++)
1054 if (gfc_simplify_expr (ref
->u
.ar
.start
[n
], type
)
1057 if (gfc_simplify_expr (ref
->u
.ar
.end
[n
], type
)
1060 if (gfc_simplify_expr (ref
->u
.ar
.stride
[n
], type
)
1067 if (gfc_simplify_expr (ref
->u
.ss
.start
, type
) == FAILURE
)
1069 if (gfc_simplify_expr (ref
->u
.ss
.end
, type
) == FAILURE
)
1081 /* Try to substitute the value of a parameter variable. */
1083 simplify_parameter_variable (gfc_expr
* p
, int type
)
1088 e
= gfc_copy_expr (p
->symtree
->n
.sym
->value
);
1089 /* Do not copy subobject refs for constant. */
1090 if (e
->expr_type
!= EXPR_CONSTANT
&& p
->ref
!= NULL
)
1091 e
->ref
= copy_ref (p
->ref
);
1092 t
= gfc_simplify_expr (e
, type
);
1094 /* Only use the simplification if it eliminated all subobject
1096 if (t
== SUCCESS
&& ! e
->ref
)
1097 gfc_replace_expr (p
, e
);
1104 /* Given an expression, simplify it by collapsing constant
1105 expressions. Most simplification takes place when the expression
1106 tree is being constructed. If an intrinsic function is simplified
1107 at some point, we get called again to collapse the result against
1110 We work by recursively simplifying expression nodes, simplifying
1111 intrinsic functions where possible, which can lead to further
1112 constant collapsing. If an operator has constant operand(s), we
1113 rip the expression apart, and rebuild it, hoping that it becomes
1116 The expression type is defined for:
1117 0 Basic expression parsing
1118 1 Simplifying array constructors -- will substitute
1120 Returns FAILURE on error, SUCCESS otherwise.
1121 NOTE: Will return SUCCESS even if the expression can not be simplified. */
1124 gfc_simplify_expr (gfc_expr
* p
, int type
)
1126 gfc_actual_arglist
*ap
;
1131 switch (p
->expr_type
)
1138 for (ap
= p
->value
.function
.actual
; ap
; ap
= ap
->next
)
1139 if (gfc_simplify_expr (ap
->expr
, type
) == FAILURE
)
1142 if (p
->value
.function
.isym
!= NULL
1143 && gfc_intrinsic_func_interface (p
, 1) == MATCH_ERROR
)
1148 case EXPR_SUBSTRING
:
1149 if (simplify_ref_chain (p
->ref
, type
) == FAILURE
)
1152 if (gfc_is_constant_expr (p
))
1157 gfc_extract_int (p
->ref
->u
.ss
.start
, &start
);
1158 start
--; /* Convert from one-based to zero-based. */
1159 gfc_extract_int (p
->ref
->u
.ss
.end
, &end
);
1160 s
= gfc_getmem (end
- start
+ 1);
1161 memcpy (s
, p
->value
.character
.string
+ start
, end
- start
);
1162 s
[end
] = '\0'; /* TODO: C-style string for debugging. */
1163 gfc_free (p
->value
.character
.string
);
1164 p
->value
.character
.string
= s
;
1165 p
->value
.character
.length
= end
- start
;
1166 p
->ts
.cl
= gfc_get_charlen ();
1167 p
->ts
.cl
->next
= gfc_current_ns
->cl_list
;
1168 gfc_current_ns
->cl_list
= p
->ts
.cl
;
1169 p
->ts
.cl
->length
= gfc_int_expr (p
->value
.character
.length
);
1170 gfc_free_ref_list (p
->ref
);
1172 p
->expr_type
= EXPR_CONSTANT
;
1177 if (simplify_intrinsic_op (p
, type
) == FAILURE
)
1182 /* Only substitute array parameter variables if we are in an
1183 initialization expression, or we want a subsection. */
1184 if (p
->symtree
->n
.sym
->attr
.flavor
== FL_PARAMETER
1185 && (gfc_init_expr
|| p
->ref
1186 || p
->symtree
->n
.sym
->value
->expr_type
!= EXPR_ARRAY
))
1188 if (simplify_parameter_variable (p
, type
) == FAILURE
)
1195 gfc_simplify_iterator_var (p
);
1198 /* Simplify subcomponent references. */
1199 if (simplify_ref_chain (p
->ref
, type
) == FAILURE
)
1204 case EXPR_STRUCTURE
:
1206 if (simplify_ref_chain (p
->ref
, type
) == FAILURE
)
1209 if (simplify_constructor (p
->value
.constructor
, type
) == FAILURE
)
1212 if (p
->expr_type
== EXPR_ARRAY
)
1213 gfc_expand_constructor (p
);
1215 if (simplify_const_ref (p
) == FAILURE
)
1225 /* Returns the type of an expression with the exception that iterator
1226 variables are automatically integers no matter what else they may
1233 if (e
->expr_type
== EXPR_VARIABLE
&& gfc_check_iter_variable (e
) == SUCCESS
)
1240 /* Check an intrinsic arithmetic operation to see if it is consistent
1241 with some type of expression. */
1243 static try check_init_expr (gfc_expr
*);
1246 check_intrinsic_op (gfc_expr
* e
, try (*check_function
) (gfc_expr
*))
1248 gfc_expr
*op1
= e
->value
.op
.op1
;
1249 gfc_expr
*op2
= e
->value
.op
.op2
;
1251 if ((*check_function
) (op1
) == FAILURE
)
1254 switch (e
->value
.op
.operator)
1256 case INTRINSIC_UPLUS
:
1257 case INTRINSIC_UMINUS
:
1258 if (!numeric_type (et0 (op1
)))
1268 if ((*check_function
) (op2
) == FAILURE
)
1271 if (!(et0 (op1
) == BT_CHARACTER
&& et0 (op2
) == BT_CHARACTER
)
1272 && !(numeric_type (et0 (op1
)) && numeric_type (et0 (op2
))))
1274 gfc_error ("Numeric or CHARACTER operands are required in "
1275 "expression at %L", &e
->where
);
1280 case INTRINSIC_PLUS
:
1281 case INTRINSIC_MINUS
:
1282 case INTRINSIC_TIMES
:
1283 case INTRINSIC_DIVIDE
:
1284 case INTRINSIC_POWER
:
1285 if ((*check_function
) (op2
) == FAILURE
)
1288 if (!numeric_type (et0 (op1
)) || !numeric_type (et0 (op2
)))
1291 if (e
->value
.op
.operator == INTRINSIC_POWER
1292 && check_function
== check_init_expr
&& et0 (op2
) != BT_INTEGER
)
1294 gfc_error ("Exponent at %L must be INTEGER for an initialization "
1295 "expression", &op2
->where
);
1301 case INTRINSIC_CONCAT
:
1302 if ((*check_function
) (op2
) == FAILURE
)
1305 if (et0 (op1
) != BT_CHARACTER
|| et0 (op2
) != BT_CHARACTER
)
1307 gfc_error ("Concatenation operator in expression at %L "
1308 "must have two CHARACTER operands", &op1
->where
);
1312 if (op1
->ts
.kind
!= op2
->ts
.kind
)
1314 gfc_error ("Concat operator at %L must concatenate strings of the "
1315 "same kind", &e
->where
);
1322 if (et0 (op1
) != BT_LOGICAL
)
1324 gfc_error (".NOT. operator in expression at %L must have a LOGICAL "
1325 "operand", &op1
->where
);
1334 case INTRINSIC_NEQV
:
1335 if ((*check_function
) (op2
) == FAILURE
)
1338 if (et0 (op1
) != BT_LOGICAL
|| et0 (op2
) != BT_LOGICAL
)
1340 gfc_error ("LOGICAL operands are required in expression at %L",
1347 case INTRINSIC_PARENTHESES
:
1351 gfc_error ("Only intrinsic operators can be used in expression at %L",
1359 gfc_error ("Numeric operands are required in expression at %L", &e
->where
);
1366 /* Certain inquiry functions are specifically allowed to have variable
1367 arguments, which is an exception to the normal requirement that an
1368 initialization function have initialization arguments. We head off
1369 this problem here. */
1372 check_inquiry (gfc_expr
* e
, int not_restricted
)
1376 /* FIXME: This should be moved into the intrinsic definitions,
1377 to eliminate this ugly hack. */
1378 static const char * const inquiry_function
[] = {
1379 "digits", "epsilon", "huge", "kind", "len", "maxexponent", "minexponent",
1380 "precision", "radix", "range", "tiny", "bit_size", "size", "shape",
1381 "lbound", "ubound", NULL
1386 /* An undeclared parameter will get us here (PR25018). */
1387 if (e
->symtree
== NULL
)
1390 name
= e
->symtree
->n
.sym
->name
;
1392 for (i
= 0; inquiry_function
[i
]; i
++)
1393 if (strcmp (inquiry_function
[i
], name
) == 0)
1396 if (inquiry_function
[i
] == NULL
)
1399 e
= e
->value
.function
.actual
->expr
;
1401 if (e
== NULL
|| e
->expr_type
!= EXPR_VARIABLE
)
1404 /* At this point we have an inquiry function with a variable argument. The
1405 type of the variable might be undefined, but we need it now, because the
1406 arguments of these functions are allowed to be undefined. */
1408 if (e
->ts
.type
== BT_UNKNOWN
)
1410 if (e
->symtree
->n
.sym
->ts
.type
== BT_UNKNOWN
1411 && gfc_set_default_type (e
->symtree
->n
.sym
, 0, gfc_current_ns
)
1415 e
->ts
= e
->symtree
->n
.sym
->ts
;
1418 /* Assumed character length will not reduce to a constant expression
1419 with LEN, as required by the standard. */
1420 if (i
== 4 && not_restricted
1421 && e
->symtree
->n
.sym
->ts
.type
== BT_CHARACTER
1422 && e
->symtree
->n
.sym
->ts
.cl
->length
== NULL
)
1423 gfc_notify_std (GFC_STD_GNU
, "assumed character length "
1424 "variable '%s' in constant expression at %L",
1425 e
->symtree
->n
.sym
->name
, &e
->where
);
1431 /* Verify that an expression is an initialization expression. A side
1432 effect is that the expression tree is reduced to a single constant
1433 node if all goes well. This would normally happen when the
1434 expression is constructed but function references are assumed to be
1435 intrinsics in the context of initialization expressions. If
1436 FAILURE is returned an error message has been generated. */
1439 check_init_expr (gfc_expr
* e
)
1441 gfc_actual_arglist
*ap
;
1448 switch (e
->expr_type
)
1451 t
= check_intrinsic_op (e
, check_init_expr
);
1453 t
= gfc_simplify_expr (e
, 0);
1460 if (check_inquiry (e
, 1) != SUCCESS
)
1463 for (ap
= e
->value
.function
.actual
; ap
; ap
= ap
->next
)
1464 if (check_init_expr (ap
->expr
) == FAILURE
)
1473 m
= gfc_intrinsic_func_interface (e
, 0);
1476 gfc_error ("Function '%s' in initialization expression at %L "
1477 "must be an intrinsic function",
1478 e
->symtree
->n
.sym
->name
, &e
->where
);
1489 if (gfc_check_iter_variable (e
) == SUCCESS
)
1492 if (e
->symtree
->n
.sym
->attr
.flavor
== FL_PARAMETER
)
1494 t
= simplify_parameter_variable (e
, 0);
1498 gfc_error ("Parameter '%s' at %L has not been declared or is "
1499 "a variable, which does not reduce to a constant "
1500 "expression", e
->symtree
->n
.sym
->name
, &e
->where
);
1509 case EXPR_SUBSTRING
:
1510 t
= check_init_expr (e
->ref
->u
.ss
.start
);
1514 t
= check_init_expr (e
->ref
->u
.ss
.end
);
1516 t
= gfc_simplify_expr (e
, 0);
1520 case EXPR_STRUCTURE
:
1521 t
= gfc_check_constructor (e
, check_init_expr
);
1525 t
= gfc_check_constructor (e
, check_init_expr
);
1529 t
= gfc_expand_constructor (e
);
1533 t
= gfc_check_constructor_type (e
);
1537 gfc_internal_error ("check_init_expr(): Unknown expression type");
1544 /* Match an initialization expression. We work by first matching an
1545 expression, then reducing it to a constant. */
1548 gfc_match_init_expr (gfc_expr
** result
)
1554 m
= gfc_match_expr (&expr
);
1559 t
= gfc_resolve_expr (expr
);
1561 t
= check_init_expr (expr
);
1566 gfc_free_expr (expr
);
1570 if (expr
->expr_type
== EXPR_ARRAY
1571 && (gfc_check_constructor_type (expr
) == FAILURE
1572 || gfc_expand_constructor (expr
) == FAILURE
))
1574 gfc_free_expr (expr
);
1578 /* Not all inquiry functions are simplified to constant expressions
1579 so it is necessary to call check_inquiry again. */
1580 if (!gfc_is_constant_expr (expr
)
1581 && check_inquiry (expr
, 1) == FAILURE
)
1583 gfc_error ("Initialization expression didn't reduce %C");
1594 static try check_restricted (gfc_expr
*);
1596 /* Given an actual argument list, test to see that each argument is a
1597 restricted expression and optionally if the expression type is
1598 integer or character. */
1601 restricted_args (gfc_actual_arglist
* a
)
1603 for (; a
; a
= a
->next
)
1605 if (check_restricted (a
->expr
) == FAILURE
)
1613 /************* Restricted/specification expressions *************/
1616 /* Make sure a non-intrinsic function is a specification function. */
1619 external_spec_function (gfc_expr
* e
)
1623 f
= e
->value
.function
.esym
;
1625 if (f
->attr
.proc
== PROC_ST_FUNCTION
)
1627 gfc_error ("Specification function '%s' at %L cannot be a statement "
1628 "function", f
->name
, &e
->where
);
1632 if (f
->attr
.proc
== PROC_INTERNAL
)
1634 gfc_error ("Specification function '%s' at %L cannot be an internal "
1635 "function", f
->name
, &e
->where
);
1639 if (!f
->attr
.pure
&& !f
->attr
.elemental
)
1641 gfc_error ("Specification function '%s' at %L must be PURE", f
->name
,
1646 if (f
->attr
.recursive
)
1648 gfc_error ("Specification function '%s' at %L cannot be RECURSIVE",
1649 f
->name
, &e
->where
);
1653 return restricted_args (e
->value
.function
.actual
);
1657 /* Check to see that a function reference to an intrinsic is a
1658 restricted expression. */
1661 restricted_intrinsic (gfc_expr
* e
)
1663 /* TODO: Check constraints on inquiry functions. 7.1.6.2 (7). */
1664 if (check_inquiry (e
, 0) == SUCCESS
)
1667 return restricted_args (e
->value
.function
.actual
);
1671 /* Verify that an expression is a restricted expression. Like its
1672 cousin check_init_expr(), an error message is generated if we
1676 check_restricted (gfc_expr
* e
)
1684 switch (e
->expr_type
)
1687 t
= check_intrinsic_op (e
, check_restricted
);
1689 t
= gfc_simplify_expr (e
, 0);
1694 t
= e
->value
.function
.esym
?
1695 external_spec_function (e
) : restricted_intrinsic (e
);
1700 sym
= e
->symtree
->n
.sym
;
1703 if (sym
->attr
.optional
)
1705 gfc_error ("Dummy argument '%s' at %L cannot be OPTIONAL",
1706 sym
->name
, &e
->where
);
1710 if (sym
->attr
.intent
== INTENT_OUT
)
1712 gfc_error ("Dummy argument '%s' at %L cannot be INTENT(OUT)",
1713 sym
->name
, &e
->where
);
1717 /* gfc_is_formal_arg broadcasts that a formal argument list is being processed
1718 in resolve.c(resolve_formal_arglist). This is done so that host associated
1719 dummy array indices are accepted (PR23446). */
1720 if (sym
->attr
.in_common
1721 || sym
->attr
.use_assoc
1723 || sym
->ns
!= gfc_current_ns
1724 || (sym
->ns
->proc_name
!= NULL
1725 && sym
->ns
->proc_name
->attr
.flavor
== FL_MODULE
)
1726 || gfc_is_formal_arg ())
1732 gfc_error ("Variable '%s' cannot appear in the expression at %L",
1733 sym
->name
, &e
->where
);
1742 case EXPR_SUBSTRING
:
1743 t
= gfc_specification_expr (e
->ref
->u
.ss
.start
);
1747 t
= gfc_specification_expr (e
->ref
->u
.ss
.end
);
1749 t
= gfc_simplify_expr (e
, 0);
1753 case EXPR_STRUCTURE
:
1754 t
= gfc_check_constructor (e
, check_restricted
);
1758 t
= gfc_check_constructor (e
, check_restricted
);
1762 gfc_internal_error ("check_restricted(): Unknown expression type");
1769 /* Check to see that an expression is a specification expression. If
1770 we return FAILURE, an error has been generated. */
1773 gfc_specification_expr (gfc_expr
* e
)
1778 if (e
->ts
.type
!= BT_INTEGER
)
1780 gfc_error ("Expression at %L must be of INTEGER type", &e
->where
);
1786 gfc_error ("Expression at %L must be scalar", &e
->where
);
1790 if (gfc_simplify_expr (e
, 0) == FAILURE
)
1793 return check_restricted (e
);
1797 /************** Expression conformance checks. *************/
1799 /* Given two expressions, make sure that the arrays are conformable. */
1802 gfc_check_conformance (const char *optype_msgid
,
1803 gfc_expr
* op1
, gfc_expr
* op2
)
1805 int op1_flag
, op2_flag
, d
;
1806 mpz_t op1_size
, op2_size
;
1809 if (op1
->rank
== 0 || op2
->rank
== 0)
1812 if (op1
->rank
!= op2
->rank
)
1814 gfc_error ("Incompatible ranks in %s at %L", _(optype_msgid
),
1821 for (d
= 0; d
< op1
->rank
; d
++)
1823 op1_flag
= gfc_array_dimen_size (op1
, d
, &op1_size
) == SUCCESS
;
1824 op2_flag
= gfc_array_dimen_size (op2
, d
, &op2_size
) == SUCCESS
;
1826 if (op1_flag
&& op2_flag
&& mpz_cmp (op1_size
, op2_size
) != 0)
1828 gfc_error ("different shape for %s at %L on dimension %d (%d/%d)",
1829 _(optype_msgid
), &op1
->where
, d
+ 1,
1830 (int) mpz_get_si (op1_size
),
1831 (int) mpz_get_si (op2_size
));
1837 mpz_clear (op1_size
);
1839 mpz_clear (op2_size
);
1849 /* Given an assignable expression and an arbitrary expression, make
1850 sure that the assignment can take place. */
1853 gfc_check_assign (gfc_expr
* lvalue
, gfc_expr
* rvalue
, int conform
)
1857 sym
= lvalue
->symtree
->n
.sym
;
1859 if (sym
->attr
.intent
== INTENT_IN
)
1861 gfc_error ("Can't assign to INTENT(IN) variable '%s' at %L",
1862 sym
->name
, &lvalue
->where
);
1866 /* 12.5.2.2, Note 12.26: The result variable is very similar to any other
1867 variable local to a function subprogram. Its existence begins when
1868 execution of the function is initiated and ends when execution of the
1869 function is terminated.....
1870 Therefore, the left hand side is no longer a varaiable, when it is:*/
1871 if (sym
->attr
.flavor
== FL_PROCEDURE
1872 && sym
->attr
.proc
!= PROC_ST_FUNCTION
1873 && !sym
->attr
.external
)
1878 /* (i) Use associated; */
1879 if (sym
->attr
.use_assoc
)
1882 /* (ii) The assignement is in the main program; or */
1883 if (gfc_current_ns
->proc_name
->attr
.is_main_program
)
1886 /* (iii) A module or internal procedure.... */
1887 if ((gfc_current_ns
->proc_name
->attr
.proc
== PROC_INTERNAL
1888 || gfc_current_ns
->proc_name
->attr
.proc
== PROC_MODULE
)
1889 && gfc_current_ns
->parent
1890 && (!(gfc_current_ns
->parent
->proc_name
->attr
.function
1891 || gfc_current_ns
->parent
->proc_name
->attr
.subroutine
)
1892 || gfc_current_ns
->parent
->proc_name
->attr
.is_main_program
))
1894 /* .... that is not a function.... */
1895 if (!gfc_current_ns
->proc_name
->attr
.function
)
1898 /* .... or is not an entry and has a different name. */
1899 if (!sym
->attr
.entry
&& sym
->name
!= gfc_current_ns
->proc_name
->name
)
1905 gfc_error ("'%s' at %L is not a VALUE", sym
->name
, &lvalue
->where
);
1910 if (rvalue
->rank
!= 0 && lvalue
->rank
!= rvalue
->rank
)
1912 gfc_error ("Incompatible ranks %d and %d in assignment at %L",
1913 lvalue
->rank
, rvalue
->rank
, &lvalue
->where
);
1917 if (lvalue
->ts
.type
== BT_UNKNOWN
)
1919 gfc_error ("Variable type is UNKNOWN in assignment at %L",
1924 if (rvalue
->expr_type
== EXPR_NULL
)
1926 gfc_error ("NULL appears on right-hand side in assignment at %L",
1931 if (sym
->attr
.cray_pointee
1932 && lvalue
->ref
!= NULL
1933 && lvalue
->ref
->u
.ar
.type
== AR_FULL
1934 && lvalue
->ref
->u
.ar
.as
->cp_was_assumed
)
1936 gfc_error ("Vector assignment to assumed-size Cray Pointee at %L"
1937 " is illegal.", &lvalue
->where
);
1941 /* This is possibly a typo: x = f() instead of x => f() */
1942 if (gfc_option
.warn_surprising
1943 && rvalue
->expr_type
== EXPR_FUNCTION
1944 && rvalue
->symtree
->n
.sym
->attr
.pointer
)
1945 gfc_warning ("POINTER valued function appears on right-hand side of "
1946 "assignment at %L", &rvalue
->where
);
1948 /* Check size of array assignments. */
1949 if (lvalue
->rank
!= 0 && rvalue
->rank
!= 0
1950 && gfc_check_conformance ("Array assignment", lvalue
, rvalue
) != SUCCESS
)
1953 if (gfc_compare_types (&lvalue
->ts
, &rvalue
->ts
))
1958 /* Numeric can be converted to any other numeric. And Hollerith can be
1959 converted to any other type. */
1960 if ((gfc_numeric_ts (&lvalue
->ts
) && gfc_numeric_ts (&rvalue
->ts
))
1961 || rvalue
->ts
.type
== BT_HOLLERITH
)
1964 if (lvalue
->ts
.type
== BT_LOGICAL
&& rvalue
->ts
.type
== BT_LOGICAL
)
1967 gfc_error ("Incompatible types in assignment at %L, %s to %s",
1968 &rvalue
->where
, gfc_typename (&rvalue
->ts
),
1969 gfc_typename (&lvalue
->ts
));
1974 return gfc_convert_type (rvalue
, &lvalue
->ts
, 1);
1978 /* Check that a pointer assignment is OK. We first check lvalue, and
1979 we only check rvalue if it's not an assignment to NULL() or a
1980 NULLIFY statement. */
1983 gfc_check_pointer_assign (gfc_expr
* lvalue
, gfc_expr
* rvalue
)
1985 symbol_attribute attr
;
1988 if (lvalue
->symtree
->n
.sym
->ts
.type
== BT_UNKNOWN
)
1990 gfc_error ("Pointer assignment target is not a POINTER at %L",
1995 if (lvalue
->symtree
->n
.sym
->attr
.flavor
== FL_PROCEDURE
1996 && lvalue
->symtree
->n
.sym
->attr
.use_assoc
)
1998 gfc_error ("'%s' in the pointer assignment at %L cannot be an "
1999 "l-value since it is a procedure",
2000 lvalue
->symtree
->n
.sym
->name
, &lvalue
->where
);
2004 attr
= gfc_variable_attr (lvalue
, NULL
);
2007 gfc_error ("Pointer assignment to non-POINTER at %L", &lvalue
->where
);
2011 is_pure
= gfc_pure (NULL
);
2013 if (is_pure
&& gfc_impure_variable (lvalue
->symtree
->n
.sym
))
2015 gfc_error ("Bad pointer object in PURE procedure at %L",
2020 /* If rvalue is a NULL() or NULLIFY, we're done. Otherwise the type,
2021 kind, etc for lvalue and rvalue must match, and rvalue must be a
2022 pure variable if we're in a pure function. */
2023 if (rvalue
->expr_type
== EXPR_NULL
&& rvalue
->ts
.type
== BT_UNKNOWN
)
2026 if (!gfc_compare_types (&lvalue
->ts
, &rvalue
->ts
))
2028 gfc_error ("Different types in pointer assignment at %L",
2033 if (lvalue
->ts
.kind
!= rvalue
->ts
.kind
)
2035 gfc_error ("Different kind type parameters in pointer "
2036 "assignment at %L", &lvalue
->where
);
2040 if (lvalue
->rank
!= rvalue
->rank
)
2042 gfc_error ("Different ranks in pointer assignment at %L",
2047 /* Now punt if we are dealing with a NULLIFY(X) or X = NULL(X). */
2048 if (rvalue
->expr_type
== EXPR_NULL
)
2051 if (lvalue
->ts
.type
== BT_CHARACTER
2052 && lvalue
->ts
.cl
->length
&& rvalue
->ts
.cl
->length
2053 && abs (gfc_dep_compare_expr (lvalue
->ts
.cl
->length
,
2054 rvalue
->ts
.cl
->length
)) == 1)
2056 gfc_error ("Different character lengths in pointer "
2057 "assignment at %L", &lvalue
->where
);
2061 attr
= gfc_expr_attr (rvalue
);
2062 if (!attr
.target
&& !attr
.pointer
)
2064 gfc_error ("Pointer assignment target is neither TARGET "
2065 "nor POINTER at %L", &rvalue
->where
);
2069 if (is_pure
&& gfc_impure_variable (rvalue
->symtree
->n
.sym
))
2071 gfc_error ("Bad target in pointer assignment in PURE "
2072 "procedure at %L", &rvalue
->where
);
2075 if (gfc_has_vector_index (rvalue
))
2077 gfc_error ("Pointer assignment with vector subscript "
2078 "on rhs at %L", &rvalue
->where
);
2086 /* Relative of gfc_check_assign() except that the lvalue is a single
2087 symbol. Used for initialization assignments. */
2090 gfc_check_assign_symbol (gfc_symbol
* sym
, gfc_expr
* rvalue
)
2095 memset (&lvalue
, '\0', sizeof (gfc_expr
));
2097 lvalue
.expr_type
= EXPR_VARIABLE
;
2098 lvalue
.ts
= sym
->ts
;
2100 lvalue
.rank
= sym
->as
->rank
;
2101 lvalue
.symtree
= (gfc_symtree
*)gfc_getmem (sizeof (gfc_symtree
));
2102 lvalue
.symtree
->n
.sym
= sym
;
2103 lvalue
.where
= sym
->declared_at
;
2105 if (sym
->attr
.pointer
)
2106 r
= gfc_check_pointer_assign (&lvalue
, rvalue
);
2108 r
= gfc_check_assign (&lvalue
, rvalue
, 1);
2110 gfc_free (lvalue
.symtree
);
2116 /* Get an expression for a default initializer. */
2119 gfc_default_initializer (gfc_typespec
*ts
)
2121 gfc_constructor
*tail
;
2127 /* See if we have a default initializer. */
2128 for (c
= ts
->derived
->components
; c
; c
= c
->next
)
2130 if (c
->initializer
&& init
== NULL
)
2131 init
= gfc_get_expr ();
2137 /* Build the constructor. */
2138 init
->expr_type
= EXPR_STRUCTURE
;
2140 init
->where
= ts
->derived
->declared_at
;
2142 for (c
= ts
->derived
->components
; c
; c
= c
->next
)
2145 init
->value
.constructor
= tail
= gfc_get_constructor ();
2148 tail
->next
= gfc_get_constructor ();
2153 tail
->expr
= gfc_copy_expr (c
->initializer
);
2159 /* Given a symbol, create an expression node with that symbol as a
2160 variable. If the symbol is array valued, setup a reference of the
2164 gfc_get_variable_expr (gfc_symtree
* var
)
2168 e
= gfc_get_expr ();
2169 e
->expr_type
= EXPR_VARIABLE
;
2171 e
->ts
= var
->n
.sym
->ts
;
2173 if (var
->n
.sym
->as
!= NULL
)
2175 e
->rank
= var
->n
.sym
->as
->rank
;
2176 e
->ref
= gfc_get_ref ();
2177 e
->ref
->type
= REF_ARRAY
;
2178 e
->ref
->u
.ar
.type
= AR_FULL
;
2185 /* Traverse expr, marking all EXPR_VARIABLE symbols referenced. */
2188 gfc_expr_set_symbols_referenced (gfc_expr
* expr
)
2190 gfc_actual_arglist
*arg
;
2197 switch (expr
->expr_type
)
2200 gfc_expr_set_symbols_referenced (expr
->value
.op
.op1
);
2201 gfc_expr_set_symbols_referenced (expr
->value
.op
.op2
);
2205 for (arg
= expr
->value
.function
.actual
; arg
; arg
= arg
->next
)
2206 gfc_expr_set_symbols_referenced (arg
->expr
);
2210 gfc_set_sym_referenced (expr
->symtree
->n
.sym
);
2215 case EXPR_SUBSTRING
:
2218 case EXPR_STRUCTURE
:
2220 for (c
= expr
->value
.constructor
; c
; c
= c
->next
)
2221 gfc_expr_set_symbols_referenced (c
->expr
);
2229 for (ref
= expr
->ref
; ref
; ref
= ref
->next
)
2233 for (i
= 0; i
< ref
->u
.ar
.dimen
; i
++)
2235 gfc_expr_set_symbols_referenced (ref
->u
.ar
.start
[i
]);
2236 gfc_expr_set_symbols_referenced (ref
->u
.ar
.end
[i
]);
2237 gfc_expr_set_symbols_referenced (ref
->u
.ar
.stride
[i
]);
2245 gfc_expr_set_symbols_referenced (ref
->u
.ss
.start
);
2246 gfc_expr_set_symbols_referenced (ref
->u
.ss
.end
);