1 /* Routines for manipulation of expression nodes.
2 Copyright (C) 2000, 2001, 2002, 2003, 2004 Free Software Foundation,
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, 59 Temple Place - Suite 330, Boston, MA
32 /* Get a new expr node. */
39 e = gfc_getmem (sizeof (gfc_expr));
41 gfc_clear_ts (&e->ts);
53 /* Free an argument list and everything below it. */
56 gfc_free_actual_arglist (gfc_actual_arglist * a1)
58 gfc_actual_arglist *a2;
63 gfc_free_expr (a1->expr);
70 /* Copy an arglist structure and all of the arguments. */
73 gfc_copy_actual_arglist (gfc_actual_arglist * p)
75 gfc_actual_arglist *head, *tail, *new;
79 for (; p; p = p->next)
81 new = gfc_get_actual_arglist ();
84 new->expr = gfc_copy_expr (p->expr);
99 /* Free a list of reference structures. */
102 gfc_free_ref_list (gfc_ref * p)
114 for (i = 0; i < GFC_MAX_DIMENSIONS; i++)
116 gfc_free_expr (p->u.ar.start[i]);
117 gfc_free_expr (p->u.ar.end[i]);
118 gfc_free_expr (p->u.ar.stride[i]);
124 gfc_free_expr (p->u.ss.start);
125 gfc_free_expr (p->u.ss.end);
137 /* Workhorse function for gfc_free_expr() that frees everything
138 beneath an expression node, but not the node itself. This is
139 useful when we want to simplify a node and replace it with
140 something else or the expression node belongs to another structure. */
143 free_expr0 (gfc_expr * e)
147 switch (e->expr_type)
153 mpz_clear (e->value.integer);
157 mpf_clear (e->value.real);
161 gfc_free (e->value.character.string);
165 mpf_clear (e->value.complex.r);
166 mpf_clear (e->value.complex.i);
177 gfc_free_expr (e->op1);
179 gfc_free_expr (e->op2);
183 gfc_free_actual_arglist (e->value.function.actual);
191 gfc_free_constructor (e->value.constructor);
195 gfc_free (e->value.character.string);
202 gfc_internal_error ("free_expr0(): Bad expr type");
205 /* Free a shape array. */
206 if (e->shape != NULL)
208 for (n = 0; n < e->rank; n++)
209 mpz_clear (e->shape[n]);
214 gfc_free_ref_list (e->ref);
216 memset (e, '\0', sizeof (gfc_expr));
220 /* Free an expression node and everything beneath it. */
223 gfc_free_expr (gfc_expr * e)
234 /* Graft the *src expression onto the *dest subexpression. */
237 gfc_replace_expr (gfc_expr * dest, gfc_expr * src)
247 /* Try to extract an integer constant from the passed expression node.
248 Returns an error message or NULL if the result is set. It is
249 tempting to generate an error and return SUCCESS or FAILURE, but
250 failure is OK for some callers. */
253 gfc_extract_int (gfc_expr * expr, int *result)
256 if (expr->expr_type != EXPR_CONSTANT)
257 return "Constant expression required at %C";
259 if (expr->ts.type != BT_INTEGER)
260 return "Integer expression required at %C";
262 if ((mpz_cmp_si (expr->value.integer, INT_MAX) > 0)
263 || (mpz_cmp_si (expr->value.integer, INT_MIN) < 0))
265 return "Integer value too large in expression at %C";
268 *result = (int) mpz_get_si (expr->value.integer);
274 /* Recursively copy a list of reference structures. */
277 copy_ref (gfc_ref * src)
285 dest = gfc_get_ref ();
286 dest->type = src->type;
291 ar = gfc_copy_array_ref (&src->u.ar);
297 dest->u.c = src->u.c;
301 dest->u.ss = src->u.ss;
302 dest->u.ss.start = gfc_copy_expr (src->u.ss.start);
303 dest->u.ss.end = gfc_copy_expr (src->u.ss.end);
307 dest->next = copy_ref (src->next);
313 /* Copy a shape array. */
316 gfc_copy_shape (mpz_t * shape, int rank)
324 new_shape = gfc_get_shape (rank);
326 for (n = 0; n < rank; n++)
327 mpz_init_set (new_shape[n], shape[n]);
333 /* Given an expression pointer, return a copy of the expression. This
334 subroutine is recursive. */
337 gfc_copy_expr (gfc_expr * p)
348 switch (q->expr_type)
351 s = gfc_getmem (p->value.character.length + 1);
352 q->value.character.string = s;
354 memcpy (s, p->value.character.string, p->value.character.length + 1);
356 q->op1 = gfc_copy_expr (p->op1);
357 q->op2 = gfc_copy_expr (p->op2);
364 mpz_init_set (q->value.integer, p->value.integer);
368 mpf_init_set (q->value.real, p->value.real);
372 mpf_init_set (q->value.complex.r, p->value.complex.r);
373 mpf_init_set (q->value.complex.i, p->value.complex.i);
377 s = gfc_getmem (p->value.character.length + 1);
378 q->value.character.string = s;
380 memcpy (s, p->value.character.string,
381 p->value.character.length + 1);
386 break; /* Already done */
390 gfc_internal_error ("gfc_copy_expr(): Bad expr node");
400 case INTRINSIC_UPLUS:
401 case INTRINSIC_UMINUS:
402 q->op1 = gfc_copy_expr (p->op1);
405 default: /* Binary operators */
406 q->op1 = gfc_copy_expr (p->op1);
407 q->op2 = gfc_copy_expr (p->op2);
414 q->value.function.actual =
415 gfc_copy_actual_arglist (p->value.function.actual);
420 q->value.constructor = gfc_copy_constructor (p->value.constructor);
428 q->shape = gfc_copy_shape (p->shape, p->rank);
430 q->ref = copy_ref (p->ref);
436 /* Return the maximum kind of two expressions. In general, higher
437 kind numbers mean more precision for numeric types. */
440 gfc_kind_max (gfc_expr * e1, gfc_expr * e2)
443 return (e1->ts.kind > e2->ts.kind) ? e1->ts.kind : e2->ts.kind;
447 /* Returns nonzero if the type is numeric, zero otherwise. */
450 numeric_type (bt type)
453 return type == BT_COMPLEX || type == BT_REAL || type == BT_INTEGER;
457 /* Returns nonzero if the typespec is a numeric type, zero otherwise. */
460 gfc_numeric_ts (gfc_typespec * ts)
463 return numeric_type (ts->type);
467 /* Returns an expression node that is an integer constant. */
476 p->expr_type = EXPR_CONSTANT;
477 p->ts.type = BT_INTEGER;
478 p->ts.kind = gfc_default_integer_kind ();
480 p->where = gfc_current_locus;
481 mpz_init_set_si (p->value.integer, i);
487 /* Returns an expression node that is a logical constant. */
490 gfc_logical_expr (int i, locus * where)
496 p->expr_type = EXPR_CONSTANT;
497 p->ts.type = BT_LOGICAL;
498 p->ts.kind = gfc_default_logical_kind ();
501 where = &gfc_current_locus;
503 p->value.logical = i;
509 /* Return an expression node with an optional argument list attached.
510 A variable number of gfc_expr pointers are strung together in an
511 argument list with a NULL pointer terminating the list. */
514 gfc_build_conversion (gfc_expr * e)
519 p->expr_type = EXPR_FUNCTION;
521 p->value.function.actual = NULL;
523 p->value.function.actual = gfc_get_actual_arglist ();
524 p->value.function.actual->expr = e;
530 /* Given an expression node with some sort of numeric binary
531 expression, insert type conversions required to make the operands
534 The exception is that the operands of an exponential don't have to
535 have the same type. If possible, the base is promoted to the type
536 of the exponent. For example, 1**2.3 becomes 1.0**2.3, but
537 1.0**2 stays as it is. */
540 gfc_type_convert_binary (gfc_expr * e)
547 if (op1->ts.type == BT_UNKNOWN || op2->ts.type == BT_UNKNOWN)
549 gfc_clear_ts (&e->ts);
553 /* Kind conversions of same type. */
554 if (op1->ts.type == op2->ts.type)
557 if (op1->ts.kind == op2->ts.kind)
559 /* No type conversions. */
564 if (op1->ts.kind > op2->ts.kind)
565 gfc_convert_type (op2, &op1->ts, 2);
567 gfc_convert_type (op1, &op2->ts, 2);
573 /* Integer combined with real or complex. */
574 if (op2->ts.type == BT_INTEGER)
578 /* Special cose for ** operator. */
579 if (e->operator == INTRINSIC_POWER)
582 gfc_convert_type (e->op2, &e->ts, 2);
586 if (op1->ts.type == BT_INTEGER)
589 gfc_convert_type (e->op1, &e->ts, 2);
593 /* Real combined with complex. */
594 e->ts.type = BT_COMPLEX;
595 if (op1->ts.kind > op2->ts.kind)
596 e->ts.kind = op1->ts.kind;
598 e->ts.kind = op2->ts.kind;
599 if (op1->ts.type != BT_COMPLEX || op1->ts.kind != e->ts.kind)
600 gfc_convert_type (e->op1, &e->ts, 2);
601 if (op2->ts.type != BT_COMPLEX || op2->ts.kind != e->ts.kind)
602 gfc_convert_type (e->op2, &e->ts, 2);
609 /* Function to determine if an expression is constant or not. This
610 function expects that the expression has already been simplified. */
613 gfc_is_constant_expr (gfc_expr * e)
616 gfc_actual_arglist *arg;
622 switch (e->expr_type)
625 rv = (gfc_is_constant_expr (e->op1)
627 || gfc_is_constant_expr (e->op2)));
636 /* Call to intrinsic with at least one argument. */
638 if (e->value.function.isym && e->value.function.actual)
640 for (arg = e->value.function.actual; arg; arg = arg->next)
642 if (!gfc_is_constant_expr (arg->expr))
656 rv = gfc_is_constant_expr (e->op1) && gfc_is_constant_expr (e->op2);
661 for (c = e->value.constructor; c; c = c->next)
662 if (!gfc_is_constant_expr (c->expr))
670 rv = gfc_constant_ac (e);
674 gfc_internal_error ("gfc_is_constant_expr(): Unknown expression type");
681 /* Try to collapse intrinsic expressions. */
684 simplify_intrinsic_op (gfc_expr * p, int type)
686 gfc_expr *op1, *op2, *result;
688 if (p->operator == INTRINSIC_USER)
694 if (gfc_simplify_expr (op1, type) == FAILURE)
696 if (gfc_simplify_expr (op2, type) == FAILURE)
699 if (!gfc_is_constant_expr (op1)
700 || (op2 != NULL && !gfc_is_constant_expr (op2)))
709 case INTRINSIC_UPLUS:
710 result = gfc_uplus (op1);
713 case INTRINSIC_UMINUS:
714 result = gfc_uminus (op1);
718 result = gfc_add (op1, op2);
721 case INTRINSIC_MINUS:
722 result = gfc_subtract (op1, op2);
725 case INTRINSIC_TIMES:
726 result = gfc_multiply (op1, op2);
729 case INTRINSIC_DIVIDE:
730 result = gfc_divide (op1, op2);
733 case INTRINSIC_POWER:
734 result = gfc_power (op1, op2);
737 case INTRINSIC_CONCAT:
738 result = gfc_concat (op1, op2);
742 result = gfc_eq (op1, op2);
746 result = gfc_ne (op1, op2);
750 result = gfc_gt (op1, op2);
754 result = gfc_ge (op1, op2);
758 result = gfc_lt (op1, op2);
762 result = gfc_le (op1, op2);
766 result = gfc_not (op1);
770 result = gfc_and (op1, op2);
774 result = gfc_or (op1, op2);
778 result = gfc_eqv (op1, op2);
782 result = gfc_neqv (op1, op2);
786 gfc_internal_error ("simplify_intrinsic_op(): Bad operator");
796 gfc_replace_expr (p, result);
802 /* Subroutine to simplify constructor expressions. Mutually recursive
803 with gfc_simplify_expr(). */
806 simplify_constructor (gfc_constructor * c, int type)
809 for (; c; c = c->next)
812 && (gfc_simplify_expr (c->iterator->start, type) == FAILURE
813 || gfc_simplify_expr (c->iterator->end, type) == FAILURE
814 || gfc_simplify_expr (c->iterator->step, type) == FAILURE))
817 if (c->expr && gfc_simplify_expr (c->expr, type) == FAILURE)
825 /* Pull a single array element out of an array constructor. */
827 static gfc_constructor *
828 find_array_element (gfc_constructor * cons, gfc_array_ref * ar)
830 unsigned long nelemen;
835 mpz_init_set_ui (offset, 0);
837 for (i = 0; i < ar->dimen; i++)
839 if (ar->start[i]->expr_type != EXPR_CONSTANT)
844 mpz_sub (delta, ar->start[i]->value.integer,
845 ar->as->lower[i]->value.integer);
846 mpz_add (offset, offset, delta);
851 if (mpz_fits_ulong_p (offset))
853 for (nelemen = mpz_get_ui (offset); nelemen > 0; nelemen--)
874 /* Find a component of a structure constructor. */
876 static gfc_constructor *
877 find_component_ref (gfc_constructor * cons, gfc_ref * ref)
882 comp = ref->u.c.sym->components;
883 pick = ref->u.c.component;
894 /* Replace an expression with the contents of a constructor, removing
895 the subobject reference in the process. */
898 remove_subobject_ref (gfc_expr * p, gfc_constructor * cons)
904 e->ref = p->ref->next;
906 gfc_replace_expr (p, e);
910 /* Simplify a subobject reference of a constructor. This occurs when
911 parameter variable values are substituted. */
914 simplify_const_ref (gfc_expr * p)
916 gfc_constructor *cons;
920 switch (p->ref->type)
923 switch (p->ref->u.ar.type)
926 cons = find_array_element (p->value.constructor, &p->ref->u.ar);
929 remove_subobject_ref (p, cons);
933 if (p->ref->next != NULL)
935 /* TODO: Simplify array subobject references. */
938 gfc_free_ref_list (p->ref);
943 /* TODO: Simplify array subsections. */
950 cons = find_component_ref (p->value.constructor, p->ref);
951 remove_subobject_ref (p, cons);
955 /* TODO: Constant substrings. */
964 /* Simplify a chain of references. */
967 simplify_ref_chain (gfc_ref * ref, int type)
971 for (; ref; ref = ref->next)
976 for (n = 0; n < ref->u.ar.dimen; n++)
978 if (gfc_simplify_expr (ref->u.ar.start[n], type)
981 if (gfc_simplify_expr (ref->u.ar.end[n], type)
984 if (gfc_simplify_expr (ref->u.ar.stride[n], type)
991 if (gfc_simplify_expr (ref->u.ss.start, type) == FAILURE)
993 if (gfc_simplify_expr (ref->u.ss.end, type) == FAILURE)
1005 /* Try to substitute the value of a parameter variable. */
1007 simplify_parameter_variable (gfc_expr * p, int type)
1012 e = gfc_copy_expr (p->symtree->n.sym->value);
1014 e->ref = copy_ref (p->ref);
1015 t = gfc_simplify_expr (e, type);
1017 /* Only use the simplification if it eliminated all subobject
1019 if (t == SUCCESS && ! e->ref)
1020 gfc_replace_expr (p, e);
1027 /* Given an expression, simplify it by collapsing constant
1028 expressions. Most simplification takes place when the expression
1029 tree is being constructed. If an intrinsic function is simplified
1030 at some point, we get called again to collapse the result against
1033 We work by recursively simplifying expression nodes, simplifying
1034 intrinsic functions where possible, which can lead to further
1035 constant collapsing. If an operator has constant operand(s), we
1036 rip the expression apart, and rebuild it, hoping that it becomes
1039 The expression type is defined for:
1040 0 Basic expression parsing
1041 1 Simplifying array constructors -- will substitute
1043 Returns FAILURE on error, SUCCESS otherwise.
1044 NOTE: Will return SUCCESS even if the expression can not be simplified. */
1047 gfc_simplify_expr (gfc_expr * p, int type)
1049 gfc_actual_arglist *ap;
1054 switch (p->expr_type)
1061 for (ap = p->value.function.actual; ap; ap = ap->next)
1062 if (gfc_simplify_expr (ap->expr, type) == FAILURE)
1065 if (p->value.function.isym != NULL
1066 && gfc_intrinsic_func_interface (p, 1) == MATCH_ERROR)
1071 case EXPR_SUBSTRING:
1072 if (gfc_simplify_expr (p->op1, type) == FAILURE
1073 || gfc_simplify_expr (p->op2, type) == FAILURE)
1076 /* TODO: evaluate constant substrings. */
1081 if (simplify_intrinsic_op (p, type) == FAILURE)
1086 /* Only substitute array parameter variables if we are in an
1087 initialization expression, or we want a subsection. */
1088 if (p->symtree->n.sym->attr.flavor == FL_PARAMETER
1089 && (gfc_init_expr || p->ref
1090 || p->symtree->n.sym->value->expr_type != EXPR_ARRAY))
1092 if (simplify_parameter_variable (p, type) == FAILURE)
1099 gfc_simplify_iterator_var (p);
1102 /* Simplify subcomponent references. */
1103 if (simplify_ref_chain (p->ref, type) == FAILURE)
1108 case EXPR_STRUCTURE:
1110 if (simplify_ref_chain (p->ref, type) == FAILURE)
1113 if (simplify_constructor (p->value.constructor, type) == FAILURE)
1116 if (p->expr_type == EXPR_ARRAY)
1117 gfc_expand_constructor (p);
1119 if (simplify_const_ref (p) == FAILURE)
1129 /* Returns the type of an expression with the exception that iterator
1130 variables are automatically integers no matter what else they may
1137 if (e->expr_type == EXPR_VARIABLE && gfc_check_iter_variable (e) == SUCCESS)
1144 /* Check an intrinsic arithmetic operation to see if it is consistent
1145 with some type of expression. */
1147 static try check_init_expr (gfc_expr *);
1150 check_intrinsic_op (gfc_expr * e, try (*check_function) (gfc_expr *))
1153 if ((*check_function) (e->op1) == FAILURE)
1156 switch (e->operator)
1158 case INTRINSIC_UPLUS:
1159 case INTRINSIC_UMINUS:
1160 if (!numeric_type (et0 (e->op1)))
1170 if ((*check_function) (e->op2) == FAILURE)
1173 if (!(et0 (e->op1) == BT_CHARACTER && et0 (e->op2) == BT_CHARACTER)
1174 && !(numeric_type (et0 (e->op1)) && numeric_type (et0 (e->op2))))
1176 gfc_error ("Numeric or CHARACTER operands are required in "
1177 "expression at %L", &e->where);
1182 case INTRINSIC_PLUS:
1183 case INTRINSIC_MINUS:
1184 case INTRINSIC_TIMES:
1185 case INTRINSIC_DIVIDE:
1186 case INTRINSIC_POWER:
1187 if ((*check_function) (e->op2) == FAILURE)
1190 if (!numeric_type (et0 (e->op1)) || !numeric_type (et0 (e->op2)))
1193 if (e->operator == INTRINSIC_POWER
1194 && check_function == check_init_expr && et0 (e->op2) != BT_INTEGER)
1196 gfc_error ("Exponent at %L must be INTEGER for an initialization "
1197 "expression", &e->op2->where);
1203 case INTRINSIC_CONCAT:
1204 if ((*check_function) (e->op2) == FAILURE)
1207 if (et0 (e->op1) != BT_CHARACTER || et0 (e->op2) != BT_CHARACTER)
1209 gfc_error ("Concatenation operator in expression at %L "
1210 "must have two CHARACTER operands", &e->op1->where);
1214 if (e->op1->ts.kind != e->op2->ts.kind)
1216 gfc_error ("Concat operator at %L must concatenate strings of the "
1217 "same kind", &e->where);
1224 if (et0 (e->op1) != BT_LOGICAL)
1226 gfc_error (".NOT. operator in expression at %L must have a LOGICAL "
1227 "operand", &e->op1->where);
1236 case INTRINSIC_NEQV:
1237 if ((*check_function) (e->op2) == FAILURE)
1240 if (et0 (e->op1) != BT_LOGICAL || et0 (e->op2) != BT_LOGICAL)
1242 gfc_error ("LOGICAL operands are required in expression at %L",
1250 gfc_error ("Only intrinsic operators can be used in expression at %L",
1258 gfc_error ("Numeric operands are required in expression at %L", &e->where);
1265 /* Certain inquiry functions are specifically allowed to have variable
1266 arguments, which is an exception to the normal requirement that an
1267 initialization function have initialization arguments. We head off
1268 this problem here. */
1271 check_inquiry (gfc_expr * e)
1275 /* FIXME: This should be moved into the intrinsic definitions,
1276 to eliminate this ugly hack. */
1277 static const char * const inquiry_function[] = {
1278 "digits", "epsilon", "huge", "kind", "maxexponent", "minexponent",
1279 "precision", "radix", "range", "tiny", "bit_size", "size", "shape",
1280 "lbound", "ubound", NULL
1285 name = e->symtree->n.sym->name;
1287 for (i = 0; inquiry_function[i]; i++)
1288 if (strcmp (inquiry_function[i], name) == 0)
1291 if (inquiry_function[i] == NULL)
1294 e = e->value.function.actual->expr;
1296 if (e == NULL || e->expr_type != EXPR_VARIABLE)
1299 /* At this point we have a numeric inquiry function with a variable
1300 argument. The type of the variable might be undefined, but we
1301 need it now, because the arguments of these functions are allowed
1304 if (e->ts.type == BT_UNKNOWN)
1306 if (e->symtree->n.sym->ts.type == BT_UNKNOWN
1307 && gfc_set_default_type (e->symtree->n.sym, 0, gfc_current_ns)
1311 e->ts = e->symtree->n.sym->ts;
1318 /* Verify that an expression is an initialization expression. A side
1319 effect is that the expression tree is reduced to a single constant
1320 node if all goes well. This would normally happen when the
1321 expression is constructed but function references are assumed to be
1322 intrinsics in the context of initialization expressions. If
1323 FAILURE is returned an error message has been generated. */
1326 check_init_expr (gfc_expr * e)
1328 gfc_actual_arglist *ap;
1335 switch (e->expr_type)
1338 t = check_intrinsic_op (e, check_init_expr);
1340 t = gfc_simplify_expr (e, 0);
1347 if (check_inquiry (e) != SUCCESS)
1350 for (ap = e->value.function.actual; ap; ap = ap->next)
1351 if (check_init_expr (ap->expr) == FAILURE)
1360 m = gfc_intrinsic_func_interface (e, 0);
1363 gfc_error ("Function '%s' in initialization expression at %L "
1364 "must be an intrinsic function",
1365 e->symtree->n.sym->name, &e->where);
1376 if (gfc_check_iter_variable (e) == SUCCESS)
1379 if (e->symtree->n.sym->attr.flavor == FL_PARAMETER)
1381 t = simplify_parameter_variable (e, 0);
1385 gfc_error ("Variable '%s' at %L cannot appear in an initialization "
1386 "expression", e->symtree->n.sym->name, &e->where);
1395 case EXPR_SUBSTRING:
1396 t = check_init_expr (e->op1);
1400 t = check_init_expr (e->op2);
1402 t = gfc_simplify_expr (e, 0);
1406 case EXPR_STRUCTURE:
1407 t = gfc_check_constructor (e, check_init_expr);
1411 t = gfc_check_constructor (e, check_init_expr);
1415 t = gfc_expand_constructor (e);
1419 t = gfc_check_constructor_type (e);
1423 gfc_internal_error ("check_init_expr(): Unknown expression type");
1430 /* Match an initialization expression. We work by first matching an
1431 expression, then reducing it to a constant. */
1434 gfc_match_init_expr (gfc_expr ** result)
1440 m = gfc_match_expr (&expr);
1445 t = gfc_resolve_expr (expr);
1447 t = check_init_expr (expr);
1452 gfc_free_expr (expr);
1456 if (expr->expr_type == EXPR_ARRAY
1457 && (gfc_check_constructor_type (expr) == FAILURE
1458 || gfc_expand_constructor (expr) == FAILURE))
1460 gfc_free_expr (expr);
1464 if (!gfc_is_constant_expr (expr))
1465 gfc_internal_error ("Initialization expression didn't reduce %C");
1474 static try check_restricted (gfc_expr *);
1476 /* Given an actual argument list, test to see that each argument is a
1477 restricted expression and optionally if the expression type is
1478 integer or character. */
1481 restricted_args (gfc_actual_arglist * a)
1483 for (; a; a = a->next)
1485 if (check_restricted (a->expr) == FAILURE)
1493 /************* Restricted/specification expressions *************/
1496 /* Make sure a non-intrinsic function is a specification function. */
1499 external_spec_function (gfc_expr * e)
1503 f = e->value.function.esym;
1505 if (f->attr.proc == PROC_ST_FUNCTION)
1507 gfc_error ("Specification function '%s' at %L cannot be a statement "
1508 "function", f->name, &e->where);
1512 if (f->attr.proc == PROC_INTERNAL)
1514 gfc_error ("Specification function '%s' at %L cannot be an internal "
1515 "function", f->name, &e->where);
1521 gfc_error ("Specification function '%s' at %L must be PURE", f->name,
1526 if (f->attr.recursive)
1528 gfc_error ("Specification function '%s' at %L cannot be RECURSIVE",
1529 f->name, &e->where);
1533 return restricted_args (e->value.function.actual);
1537 /* Check to see that a function reference to an intrinsic is a
1538 restricted expression. */
1541 restricted_intrinsic (gfc_expr * e)
1543 /* TODO: Check constraints on inquiry functions. 7.1.6.2 (7). */
1544 if (check_inquiry (e) == SUCCESS)
1547 return restricted_args (e->value.function.actual);
1551 /* Verify that an expression is a restricted expression. Like its
1552 cousin check_init_expr(), an error message is generated if we
1556 check_restricted (gfc_expr * e)
1564 switch (e->expr_type)
1567 t = check_intrinsic_op (e, check_restricted);
1569 t = gfc_simplify_expr (e, 0);
1574 t = e->value.function.esym ?
1575 external_spec_function (e) : restricted_intrinsic (e);
1580 sym = e->symtree->n.sym;
1583 if (sym->attr.optional)
1585 gfc_error ("Dummy argument '%s' at %L cannot be OPTIONAL",
1586 sym->name, &e->where);
1590 if (sym->attr.intent == INTENT_OUT)
1592 gfc_error ("Dummy argument '%s' at %L cannot be INTENT(OUT)",
1593 sym->name, &e->where);
1597 if (sym->attr.in_common
1598 || sym->attr.use_assoc
1600 || sym->ns != gfc_current_ns
1601 || (sym->ns->proc_name != NULL
1602 && sym->ns->proc_name->attr.flavor == FL_MODULE))
1608 gfc_error ("Variable '%s' cannot appear in the expression at %L",
1609 sym->name, &e->where);
1618 case EXPR_SUBSTRING:
1619 t = gfc_specification_expr (e->op1);
1623 t = gfc_specification_expr (e->op2);
1625 t = gfc_simplify_expr (e, 0);
1629 case EXPR_STRUCTURE:
1630 t = gfc_check_constructor (e, check_restricted);
1634 t = gfc_check_constructor (e, check_restricted);
1638 gfc_internal_error ("check_restricted(): Unknown expression type");
1645 /* Check to see that an expression is a specification expression. If
1646 we return FAILURE, an error has been generated. */
1649 gfc_specification_expr (gfc_expr * e)
1652 if (e->ts.type != BT_INTEGER)
1654 gfc_error ("Expression at %L must be of INTEGER type", &e->where);
1660 gfc_error ("Expression at %L must be scalar", &e->where);
1664 if (gfc_simplify_expr (e, 0) == FAILURE)
1667 return check_restricted (e);
1671 /************** Expression conformance checks. *************/
1673 /* Given two expressions, make sure that the arrays are conformable. */
1676 gfc_check_conformance (const char *optype, gfc_expr * op1, gfc_expr * op2)
1678 int op1_flag, op2_flag, d;
1679 mpz_t op1_size, op2_size;
1682 if (op1->rank == 0 || op2->rank == 0)
1685 if (op1->rank != op2->rank)
1687 gfc_error ("Incompatible ranks in %s at %L", optype, &op1->where);
1693 for (d = 0; d < op1->rank; d++)
1695 op1_flag = gfc_array_dimen_size (op1, d, &op1_size) == SUCCESS;
1696 op2_flag = gfc_array_dimen_size (op2, d, &op2_size) == SUCCESS;
1698 if (op1_flag && op2_flag && mpz_cmp (op1_size, op2_size) != 0)
1700 gfc_error ("%s at %L has different shape on dimension %d (%d/%d)",
1701 optype, &op1->where, d + 1, (int) mpz_get_si (op1_size),
1702 (int) mpz_get_si (op2_size));
1708 mpz_clear (op1_size);
1710 mpz_clear (op2_size);
1720 /* Given an assignable expression and an arbitrary expression, make
1721 sure that the assignment can take place. */
1724 gfc_check_assign (gfc_expr * lvalue, gfc_expr * rvalue, int conform)
1728 sym = lvalue->symtree->n.sym;
1730 if (sym->attr.intent == INTENT_IN)
1732 gfc_error ("Can't assign to INTENT(IN) variable '%s' at %L",
1733 sym->name, &lvalue->where);
1737 if (rvalue->rank != 0 && lvalue->rank != rvalue->rank)
1739 gfc_error ("Incompatible ranks in assignment at %L", &lvalue->where);
1743 if (lvalue->ts.type == BT_UNKNOWN)
1745 gfc_error ("Variable type is UNKNOWN in assignment at %L",
1750 /* Check size of array assignments. */
1751 if (lvalue->rank != 0 && rvalue->rank != 0
1752 && gfc_check_conformance ("Array assignment", lvalue, rvalue) != SUCCESS)
1755 if (gfc_compare_types (&lvalue->ts, &rvalue->ts))
1760 if (gfc_numeric_ts (&lvalue->ts) && gfc_numeric_ts (&rvalue->ts))
1763 gfc_error ("Incompatible types in assignment at %L, %s to %s",
1764 &rvalue->where, gfc_typename (&rvalue->ts),
1765 gfc_typename (&lvalue->ts));
1770 return gfc_convert_type (rvalue, &lvalue->ts, 1);
1774 /* Check that a pointer assignment is OK. We first check lvalue, and
1775 we only check rvalue if it's not an assignment to NULL() or a
1776 NULLIFY statement. */
1779 gfc_check_pointer_assign (gfc_expr * lvalue, gfc_expr * rvalue)
1781 symbol_attribute attr;
1784 if (lvalue->symtree->n.sym->ts.type == BT_UNKNOWN)
1786 gfc_error ("Pointer assignment target is not a POINTER at %L",
1791 attr = gfc_variable_attr (lvalue, NULL);
1794 gfc_error ("Pointer assignment to non-POINTER at %L", &lvalue->where);
1798 is_pure = gfc_pure (NULL);
1800 if (is_pure && gfc_impure_variable (lvalue->symtree->n.sym))
1802 gfc_error ("Bad pointer object in PURE procedure at %L",
1807 /* If rvalue is a NULL() or NULLIFY, we're done. Otherwise the type,
1808 kind, etc for lvalue and rvalue must match, and rvalue must be a
1809 pure variable if we're in a pure function. */
1810 if (rvalue->expr_type != EXPR_NULL)
1813 if (!gfc_compare_types (&lvalue->ts, &rvalue->ts))
1815 gfc_error ("Different types in pointer assignment at %L",
1820 if (lvalue->ts.kind != rvalue->ts.kind)
1823 ("Different kind type parameters in pointer assignment at %L",
1828 attr = gfc_expr_attr (rvalue);
1829 if (!attr.target && !attr.pointer)
1832 ("Pointer assignment target is neither TARGET nor POINTER at "
1833 "%L", &rvalue->where);
1837 if (is_pure && gfc_impure_variable (rvalue->symtree->n.sym))
1840 ("Bad target in pointer assignment in PURE procedure at %L",
1849 /* Relative of gfc_check_assign() except that the lvalue is a single
1853 gfc_check_assign_symbol (gfc_symbol * sym, gfc_expr * rvalue)
1858 memset (&lvalue, '\0', sizeof (gfc_expr));
1860 lvalue.expr_type = EXPR_VARIABLE;
1861 lvalue.ts = sym->ts;
1863 lvalue.rank = sym->as->rank;
1864 lvalue.symtree = (gfc_symtree *)gfc_getmem (sizeof (gfc_symtree));
1865 lvalue.symtree->n.sym = sym;
1866 lvalue.where = sym->declared_at;
1868 r = gfc_check_assign (&lvalue, rvalue, 1);
1870 gfc_free (lvalue.symtree);
1876 /* Get an expression for a default initializer. */
1879 gfc_default_initializer (gfc_typespec *ts)
1881 gfc_constructor *tail;
1887 /* See if we have a default initializer. */
1888 for (c = ts->derived->components; c; c = c->next)
1890 if (c->initializer && init == NULL)
1891 init = gfc_get_expr ();
1897 /* Build the constructor. */
1898 init->expr_type = EXPR_STRUCTURE;
1900 init->where = ts->derived->declared_at;
1902 for (c = ts->derived->components; c; c = c->next)
1905 init->value.constructor = tail = gfc_get_constructor ();
1908 tail->next = gfc_get_constructor ();
1913 tail->expr = gfc_copy_expr (c->initializer);