1 /* Deal with interfaces.
2 Copyright (C) 2000, 2001, 2002, 2004, 2005 Free Software Foundation, Inc.
3 Contributed by Andy Vaught
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 2, 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 COPYING. If not, write to the Free
19 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
23 /* Deal with interfaces. An explicit interface is represented as a
24 singly linked list of formal argument structures attached to the
25 relevant symbols. For an implicit interface, the arguments don't
26 point to symbols. Explicit interfaces point to namespaces that
27 contain the symbols within that interface.
29 Implicit interfaces are linked together in a singly linked list
30 along the next_if member of symbol nodes. Since a particular
31 symbol can only have a single explicit interface, the symbol cannot
32 be part of multiple lists and a single next-member suffices.
34 This is not the case for general classes, though. An operator
35 definition is independent of just about all other uses and has it's
39 Nameless interfaces create symbols with explicit interfaces within
40 the current namespace. They are otherwise unlinked.
43 The generic name points to a linked list of symbols. Each symbol
44 has an explicit interface. Each explicit interface has its own
45 namespace containing the arguments. Module procedures are symbols in
46 which the interface is added later when the module procedure is parsed.
49 User-defined operators are stored in a their own set of symtrees
50 separate from regular symbols. The symtrees point to gfc_user_op
51 structures which in turn head up a list of relevant interfaces.
53 Extended intrinsics and assignment:
54 The head of these interface lists are stored in the containing namespace.
57 An implicit interface is represented as a singly linked list of
58 formal argument list structures that don't point to any symbol
59 nodes -- they just contain types.
62 When a subprogram is defined, the program unit's name points to an
63 interface as usual, but the link to the namespace is NULL and the
64 formal argument list points to symbols within the same namespace as
65 the program unit name. */
73 /* The current_interface structure holds information about the
74 interface currently being parsed. This structure is saved and
75 restored during recursive interfaces. */
77 gfc_interface_info current_interface;
80 /* Free a singly linked list of gfc_interface structures. */
83 gfc_free_interface (gfc_interface * intr)
87 for (; intr; intr = next)
95 /* Change the operators unary plus and minus into binary plus and
96 minus respectively, leaving the rest unchanged. */
98 static gfc_intrinsic_op
99 fold_unary (gfc_intrinsic_op operator)
104 case INTRINSIC_UPLUS:
105 operator = INTRINSIC_PLUS;
107 case INTRINSIC_UMINUS:
108 operator = INTRINSIC_MINUS;
118 /* Match a generic specification. Depending on which type of
119 interface is found, the 'name' or 'operator' pointers may be set.
120 This subroutine doesn't return MATCH_NO. */
123 gfc_match_generic_spec (interface_type * type,
125 gfc_intrinsic_op *operator)
127 char buffer[GFC_MAX_SYMBOL_LEN + 1];
131 if (gfc_match (" assignment ( = )") == MATCH_YES)
133 *type = INTERFACE_INTRINSIC_OP;
134 *operator = INTRINSIC_ASSIGN;
138 if (gfc_match (" operator ( %o )", &i) == MATCH_YES)
140 *type = INTERFACE_INTRINSIC_OP;
141 *operator = fold_unary (i);
145 if (gfc_match (" operator ( ") == MATCH_YES)
147 m = gfc_match_defined_op_name (buffer, 1);
153 m = gfc_match_char (')');
159 strcpy (name, buffer);
160 *type = INTERFACE_USER_OP;
164 if (gfc_match_name (buffer) == MATCH_YES)
166 strcpy (name, buffer);
167 *type = INTERFACE_GENERIC;
171 *type = INTERFACE_NAMELESS;
175 gfc_error ("Syntax error in generic specification at %C");
180 /* Match one of the five forms of an interface statement. */
183 gfc_match_interface (void)
185 char name[GFC_MAX_SYMBOL_LEN + 1];
188 gfc_intrinsic_op operator;
191 m = gfc_match_space ();
193 if (gfc_match_generic_spec (&type, name, &operator) == MATCH_ERROR)
197 /* If we're not looking at the end of the statement now, or if this
198 is not a nameless interface but we did not see a space, punt. */
199 if (gfc_match_eos () != MATCH_YES
200 || (type != INTERFACE_NAMELESS
204 ("Syntax error: Trailing garbage in INTERFACE statement at %C");
208 current_interface.type = type;
212 case INTERFACE_GENERIC:
213 if (gfc_get_symbol (name, NULL, &sym))
216 if (!sym->attr.generic
217 && gfc_add_generic (&sym->attr, sym->name, NULL) == FAILURE)
220 current_interface.sym = gfc_new_block = sym;
223 case INTERFACE_USER_OP:
224 current_interface.uop = gfc_get_uop (name);
227 case INTERFACE_INTRINSIC_OP:
228 current_interface.op = operator;
231 case INTERFACE_NAMELESS:
239 /* Match the different sort of generic-specs that can be present after
240 the END INTERFACE itself. */
243 gfc_match_end_interface (void)
245 char name[GFC_MAX_SYMBOL_LEN + 1];
247 gfc_intrinsic_op operator;
250 m = gfc_match_space ();
252 if (gfc_match_generic_spec (&type, name, &operator) == MATCH_ERROR)
255 /* If we're not looking at the end of the statement now, or if this
256 is not a nameless interface but we did not see a space, punt. */
257 if (gfc_match_eos () != MATCH_YES
258 || (type != INTERFACE_NAMELESS
262 ("Syntax error: Trailing garbage in END INTERFACE statement at %C");
268 switch (current_interface.type)
270 case INTERFACE_NAMELESS:
271 if (type != current_interface.type)
273 gfc_error ("Expected a nameless interface at %C");
279 case INTERFACE_INTRINSIC_OP:
280 if (type != current_interface.type || operator != current_interface.op)
283 if (current_interface.op == INTRINSIC_ASSIGN)
284 gfc_error ("Expected 'END INTERFACE ASSIGNMENT (=)' at %C");
286 gfc_error ("Expecting 'END INTERFACE OPERATOR (%s)' at %C",
287 gfc_op2string (current_interface.op));
294 case INTERFACE_USER_OP:
295 /* Comparing the symbol node names is OK because only use-associated
296 symbols can be renamed. */
297 if (type != current_interface.type
298 || strcmp (current_interface.uop->name, name) != 0)
300 gfc_error ("Expecting 'END INTERFACE OPERATOR (.%s.)' at %C",
301 current_interface.uop->name);
307 case INTERFACE_GENERIC:
308 if (type != current_interface.type
309 || strcmp (current_interface.sym->name, name) != 0)
311 gfc_error ("Expecting 'END INTERFACE %s' at %C",
312 current_interface.sym->name);
323 /* Compare two derived types using the criteria in 4.4.2 of the standard,
324 recursing through gfc_compare_types for the components. */
327 gfc_compare_derived_types (gfc_symbol * derived1, gfc_symbol * derived2)
329 gfc_component *dt1, *dt2;
331 /* Special case for comparing derived types across namespaces. If the
332 true names and module names are the same and the module name is
333 nonnull, then they are equal. */
334 if (strcmp (derived1->name, derived2->name) == 0
335 && derived1 != NULL && derived2 != NULL
336 && derived1->module != NULL && derived2->module != NULL
337 && strcmp (derived1->module, derived2->module) == 0)
340 /* Compare type via the rules of the standard. Both types must have
341 the SEQUENCE attribute to be equal. */
343 if (strcmp (derived1->name, derived2->name))
346 if (derived1->component_access == ACCESS_PRIVATE
347 || derived2->component_access == ACCESS_PRIVATE)
350 if (derived1->attr.sequence == 0 || derived2->attr.sequence == 0)
353 dt1 = derived1->components;
354 dt2 = derived2->components;
356 /* Since subtypes of SEQUENCE types must be SEQUENCE types as well, a
357 simple test can speed things up. Otherwise, lots of things have to
361 if (strcmp (dt1->name, dt2->name) != 0)
364 if (dt1->pointer != dt2->pointer)
367 if (dt1->dimension != dt2->dimension)
370 if (dt1->dimension && gfc_compare_array_spec (dt1->as, dt2->as) == 0)
373 if (gfc_compare_types (&dt1->ts, &dt2->ts) == 0)
379 if (dt1 == NULL && dt2 == NULL)
381 if (dt1 == NULL || dt2 == NULL)
388 /* Compare two typespecs, recursively if necessary. */
391 gfc_compare_types (gfc_typespec * ts1, gfc_typespec * ts2)
394 if (ts1->type != ts2->type)
396 if (ts1->type != BT_DERIVED)
397 return (ts1->kind == ts2->kind);
399 /* Compare derived types. */
400 if (ts1->derived == ts2->derived)
403 return gfc_compare_derived_types (ts1->derived ,ts2->derived);
407 /* Given two symbols that are formal arguments, compare their ranks
408 and types. Returns nonzero if they have the same rank and type,
412 compare_type_rank (gfc_symbol * s1, gfc_symbol * s2)
416 r1 = (s1->as != NULL) ? s1->as->rank : 0;
417 r2 = (s2->as != NULL) ? s2->as->rank : 0;
420 return 0; /* Ranks differ */
422 return gfc_compare_types (&s1->ts, &s2->ts);
426 static int compare_interfaces (gfc_symbol *, gfc_symbol *, int);
428 /* Given two symbols that are formal arguments, compare their types
429 and rank and their formal interfaces if they are both dummy
430 procedures. Returns nonzero if the same, zero if different. */
433 compare_type_rank_if (gfc_symbol * s1, gfc_symbol * s2)
436 if (s1->attr.flavor != FL_PROCEDURE && s2->attr.flavor != FL_PROCEDURE)
437 return compare_type_rank (s1, s2);
439 if (s1->attr.flavor != FL_PROCEDURE || s2->attr.flavor != FL_PROCEDURE)
442 /* At this point, both symbols are procedures. */
443 if ((s1->attr.function == 0 && s1->attr.subroutine == 0)
444 || (s2->attr.function == 0 && s2->attr.subroutine == 0))
447 if (s1->attr.function != s2->attr.function
448 || s1->attr.subroutine != s2->attr.subroutine)
451 if (s1->attr.function && compare_type_rank (s1, s2) == 0)
454 return compare_interfaces (s1, s2, 0); /* Recurse! */
458 /* Given a formal argument list and a keyword name, search the list
459 for that keyword. Returns the correct symbol node if found, NULL
463 find_keyword_arg (const char *name, gfc_formal_arglist * f)
466 for (; f; f = f->next)
467 if (strcmp (f->sym->name, name) == 0)
474 /******** Interface checking subroutines **********/
477 /* Given an operator interface and the operator, make sure that all
478 interfaces for that operator are legal. */
481 check_operator_interface (gfc_interface * intr, gfc_intrinsic_op operator)
483 gfc_formal_arglist *formal;
493 t1 = t2 = BT_UNKNOWN;
494 i1 = i2 = INTENT_UNKNOWN;
496 for (formal = intr->sym->formal; formal; formal = formal->next)
503 i1 = sym->attr.intent;
508 i2 = sym->attr.intent;
513 if (args == 0 || args > 2)
518 if (operator == INTRINSIC_ASSIGN)
520 if (!sym->attr.subroutine)
523 ("Assignment operator interface at %L must be a SUBROUTINE",
530 if (!sym->attr.function)
532 gfc_error ("Intrinsic operator interface at %L must be a FUNCTION",
540 case INTRINSIC_PLUS: /* Numeric unary or binary */
541 case INTRINSIC_MINUS:
545 || t1 == BT_COMPLEX))
549 && (t1 == BT_INTEGER || t1 == BT_REAL || t1 == BT_COMPLEX)
550 && (t2 == BT_INTEGER || t2 == BT_REAL || t2 == BT_COMPLEX))
555 case INTRINSIC_POWER: /* Binary numeric */
556 case INTRINSIC_TIMES:
557 case INTRINSIC_DIVIDE:
564 if ((t1 == BT_INTEGER || t1 == BT_REAL || t1 == BT_COMPLEX)
565 && (t2 == BT_INTEGER || t2 == BT_REAL || t2 == BT_COMPLEX))
570 case INTRINSIC_GE: /* Binary numeric operators that do not support */
571 case INTRINSIC_LE: /* complex numbers */
577 if ((t1 == BT_INTEGER || t1 == BT_REAL)
578 && (t2 == BT_INTEGER || t2 == BT_REAL))
583 case INTRINSIC_OR: /* Binary logical */
589 if (t1 == BT_LOGICAL && t2 == BT_LOGICAL)
593 case INTRINSIC_NOT: /* Unary logical */
596 if (t1 == BT_LOGICAL)
600 case INTRINSIC_CONCAT: /* Binary string */
603 if (t1 == BT_CHARACTER && t2 == BT_CHARACTER)
607 case INTRINSIC_ASSIGN: /* Class by itself */
612 gfc_internal_error ("check_operator_interface(): Bad operator");
615 /* Check intents on operator interfaces. */
616 if (operator == INTRINSIC_ASSIGN)
618 if (i1 != INTENT_OUT && i1 != INTENT_INOUT)
619 gfc_error ("First argument of defined assignment at %L must be "
620 "INTENT(IN) or INTENT(INOUT)", &intr->where);
623 gfc_error ("Second argument of defined assignment at %L must be "
624 "INTENT(IN)", &intr->where);
629 gfc_error ("First argument of operator interface at %L must be "
630 "INTENT(IN)", &intr->where);
632 if (args == 2 && i2 != INTENT_IN)
633 gfc_error ("Second argument of operator interface at %L must be "
634 "INTENT(IN)", &intr->where);
640 gfc_error ("Operator interface at %L conflicts with intrinsic interface",
645 gfc_error ("Operator interface at %L has the wrong number of arguments",
651 /* Given a pair of formal argument lists, we see if the two lists can
652 be distinguished by counting the number of nonoptional arguments of
653 a given type/rank in f1 and seeing if there are less then that
654 number of those arguments in f2 (including optional arguments).
655 Since this test is asymmetric, it has to be called twice to make it
656 symmetric. Returns nonzero if the argument lists are incompatible
657 by this test. This subroutine implements rule 1 of section
661 count_types_test (gfc_formal_arglist * f1, gfc_formal_arglist * f2)
663 int rc, ac1, ac2, i, j, k, n1;
664 gfc_formal_arglist *f;
677 for (f = f1; f; f = f->next)
680 /* Build an array of integers that gives the same integer to
681 arguments of the same type/rank. */
682 arg = gfc_getmem (n1 * sizeof (arginfo));
685 for (i = 0; i < n1; i++, f = f->next)
693 for (i = 0; i < n1; i++)
695 if (arg[i].flag != -1)
698 if (arg[i].sym->attr.optional)
699 continue; /* Skip optional arguments */
703 /* Find other nonoptional arguments of the same type/rank. */
704 for (j = i + 1; j < n1; j++)
705 if (!arg[j].sym->attr.optional
706 && compare_type_rank_if (arg[i].sym, arg[j].sym))
712 /* Now loop over each distinct type found in f1. */
716 for (i = 0; i < n1; i++)
718 if (arg[i].flag != k)
722 for (j = i + 1; j < n1; j++)
723 if (arg[j].flag == k)
726 /* Count the number of arguments in f2 with that type, including
727 those that are optional. */
730 for (f = f2; f; f = f->next)
731 if (compare_type_rank_if (arg[i].sym, f->sym))
749 /* Perform the abbreviated correspondence test for operators. The
750 arguments cannot be optional and are always ordered correctly,
751 which makes this test much easier than that for generic tests.
753 This subroutine is also used when comparing a formal and actual
754 argument list when an actual parameter is a dummy procedure. At
755 that point, two formal interfaces must be compared for equality
756 which is what happens here. */
759 operator_correspondence (gfc_formal_arglist * f1, gfc_formal_arglist * f2)
763 if (f1 == NULL && f2 == NULL)
765 if (f1 == NULL || f2 == NULL)
768 if (!compare_type_rank (f1->sym, f2->sym))
779 /* Perform the correspondence test in rule 2 of section 14.1.2.3.
780 Returns zero if no argument is found that satisfies rule 2, nonzero
783 This test is also not symmetric in f1 and f2 and must be called
784 twice. This test finds problems caused by sorting the actual
785 argument list with keywords. For example:
789 INTEGER :: A ; REAL :: B
793 INTEGER :: A ; REAL :: B
797 At this point, 'CALL FOO(A=1, B=1.0)' is ambiguous. */
800 generic_correspondence (gfc_formal_arglist * f1, gfc_formal_arglist * f2)
803 gfc_formal_arglist *f2_save, *g;
810 if (f1->sym->attr.optional)
813 if (f2 != NULL && compare_type_rank (f1->sym, f2->sym))
816 /* Now search for a disambiguating keyword argument starting at
817 the current non-match. */
818 for (g = f1; g; g = g->next)
820 if (g->sym->attr.optional)
823 sym = find_keyword_arg (g->sym->name, f2_save);
824 if (sym == NULL || !compare_type_rank (g->sym, sym))
838 /* 'Compare' two formal interfaces associated with a pair of symbols.
839 We return nonzero if there exists an actual argument list that
840 would be ambiguous between the two interfaces, zero otherwise. */
843 compare_interfaces (gfc_symbol * s1, gfc_symbol * s2, int generic_flag)
845 gfc_formal_arglist *f1, *f2;
847 if (s1->attr.function != s2->attr.function
848 && s1->attr.subroutine != s2->attr.subroutine)
849 return 0; /* disagreement between function/subroutine */
854 if (f1 == NULL && f2 == NULL)
855 return 1; /* Special case */
857 if (count_types_test (f1, f2))
859 if (count_types_test (f2, f1))
864 if (generic_correspondence (f1, f2))
866 if (generic_correspondence (f2, f1))
871 if (operator_correspondence (f1, f2))
879 /* Given a pointer to an interface pointer, remove duplicate
880 interfaces and make sure that all symbols are either functions or
881 subroutines. Returns nonzero if something goes wrong. */
884 check_interface0 (gfc_interface * p, const char *interface_name)
886 gfc_interface *psave, *q, *qlast;
889 /* Make sure all symbols in the interface have been defined as
890 functions or subroutines. */
891 for (; p; p = p->next)
892 if (!p->sym->attr.function && !p->sym->attr.subroutine)
894 gfc_error ("Procedure '%s' in %s at %L is neither function nor "
895 "subroutine", p->sym->name, interface_name,
896 &p->sym->declared_at);
901 /* Remove duplicate interfaces in this interface list. */
902 for (; p; p = p->next)
906 for (q = p->next; q;)
908 if (p->sym != q->sym)
916 /* Duplicate interface */
917 qlast->next = q->next;
928 /* Check lists of interfaces to make sure that no two interfaces are
929 ambiguous. Duplicate interfaces (from the same symbol) are OK
933 check_interface1 (gfc_interface * p, gfc_interface * q,
934 int generic_flag, const char *interface_name)
937 for (; p; p = p->next)
938 for (; q; q = q->next)
940 if (p->sym == q->sym)
941 continue; /* Duplicates OK here */
943 if (p->sym->name == q->sym->name && p->sym->module == q->sym->module)
946 if (compare_interfaces (p->sym, q->sym, generic_flag))
948 gfc_error ("Ambiguous interfaces '%s' and '%s' in %s at %L",
949 p->sym->name, q->sym->name, interface_name, &p->where);
958 /* Check the generic and operator interfaces of symbols to make sure
959 that none of the interfaces conflict. The check has to be done
960 after all of the symbols are actually loaded. */
963 check_sym_interfaces (gfc_symbol * sym)
965 char interface_name[100];
968 if (sym->ns != gfc_current_ns)
971 if (sym->generic != NULL)
973 sprintf (interface_name, "generic interface '%s'", sym->name);
974 if (check_interface0 (sym->generic, interface_name))
980 if (check_interface1 (sym->generic, s2->generic, 1, interface_name))
983 if (s2->ns->parent == NULL)
985 if (gfc_find_symbol (sym->name, s2->ns->parent, 1, &s2))
993 check_uop_interfaces (gfc_user_op * uop)
995 char interface_name[100];
999 sprintf (interface_name, "operator interface '%s'", uop->name);
1000 if (check_interface0 (uop->operator, interface_name))
1003 for (ns = gfc_current_ns; ns; ns = ns->parent)
1005 uop2 = gfc_find_uop (uop->name, ns);
1009 check_interface1 (uop->operator, uop2->operator, 0, interface_name);
1014 /* For the namespace, check generic, user operator and intrinsic
1015 operator interfaces for consistency and to remove duplicate
1016 interfaces. We traverse the whole namespace, counting on the fact
1017 that most symbols will not have generic or operator interfaces. */
1020 gfc_check_interfaces (gfc_namespace * ns)
1022 gfc_namespace *old_ns, *ns2;
1023 char interface_name[100];
1026 old_ns = gfc_current_ns;
1027 gfc_current_ns = ns;
1029 gfc_traverse_ns (ns, check_sym_interfaces);
1031 gfc_traverse_user_op (ns, check_uop_interfaces);
1033 for (i = GFC_INTRINSIC_BEGIN; i != GFC_INTRINSIC_END; i++)
1035 if (i == INTRINSIC_USER)
1038 if (i == INTRINSIC_ASSIGN)
1039 strcpy (interface_name, "intrinsic assignment operator");
1041 sprintf (interface_name, "intrinsic '%s' operator",
1044 if (check_interface0 (ns->operator[i], interface_name))
1047 check_operator_interface (ns->operator[i], i);
1049 for (ns2 = ns->parent; ns2; ns2 = ns2->parent)
1050 if (check_interface1 (ns->operator[i], ns2->operator[i], 0,
1055 gfc_current_ns = old_ns;
1060 symbol_rank (gfc_symbol * sym)
1063 return (sym->as == NULL) ? 0 : sym->as->rank;
1067 /* Given a symbol of a formal argument list and an expression, if the
1068 formal argument is a pointer, see if the actual argument is a
1069 pointer. Returns nonzero if compatible, zero if not compatible. */
1072 compare_pointer (gfc_symbol * formal, gfc_expr * actual)
1074 symbol_attribute attr;
1076 if (formal->attr.pointer)
1078 attr = gfc_expr_attr (actual);
1087 /* Given a symbol of a formal argument list and an expression, see if
1088 the two are compatible as arguments. Returns nonzero if
1089 compatible, zero if not compatible. */
1092 compare_parameter (gfc_symbol * formal, gfc_expr * actual,
1093 int ranks_must_agree, int is_elemental)
1097 if (actual->ts.type == BT_PROCEDURE)
1099 if (formal->attr.flavor != FL_PROCEDURE)
1102 if (formal->attr.function
1103 && !compare_type_rank (formal, actual->symtree->n.sym))
1106 if (formal->attr.if_source == IFSRC_UNKNOWN)
1107 return 1; /* Assume match */
1109 return compare_interfaces (formal, actual->symtree->n.sym, 0);
1112 if ((actual->expr_type != EXPR_NULL || actual->ts.type != BT_UNKNOWN)
1113 && !gfc_compare_types (&formal->ts, &actual->ts))
1116 if (symbol_rank (formal) == actual->rank)
1119 /* At this point the ranks didn't agree. */
1120 if (ranks_must_agree || formal->attr.pointer)
1123 if (actual->rank != 0)
1124 return is_elemental || formal->attr.dimension;
1126 /* At this point, we are considering a scalar passed to an array.
1127 This is legal if the scalar is an array element of the right sort. */
1128 if (formal->as->type == AS_ASSUMED_SHAPE)
1131 for (ref = actual->ref; ref; ref = ref->next)
1132 if (ref->type == REF_SUBSTRING)
1135 for (ref = actual->ref; ref; ref = ref->next)
1136 if (ref->type == REF_ARRAY && ref->u.ar.type == AR_ELEMENT)
1140 return 0; /* Not an array element */
1146 /* Given formal and actual argument lists, see if they are compatible.
1147 If they are compatible, the actual argument list is sorted to
1148 correspond with the formal list, and elements for missing optional
1149 arguments are inserted. If WHERE pointer is nonnull, then we issue
1150 errors when things don't match instead of just returning the status
1154 compare_actual_formal (gfc_actual_arglist ** ap,
1155 gfc_formal_arglist * formal,
1156 int ranks_must_agree, int is_elemental, locus * where)
1158 gfc_actual_arglist **new, *a, *actual, temp;
1159 gfc_formal_arglist *f;
1164 if (actual == NULL && formal == NULL)
1168 for (f = formal; f; f = f->next)
1171 new = (gfc_actual_arglist **) alloca (n * sizeof (gfc_actual_arglist *));
1173 for (i = 0; i < n; i++)
1180 for (a = actual; a; a = a->next, f = f->next)
1182 if (a->name != NULL)
1185 for (f = formal; f; f = f->next, i++)
1189 if (strcmp (f->sym->name, a->name) == 0)
1197 ("Keyword argument '%s' at %L is not in the procedure",
1198 a->name, &a->expr->where);
1206 ("Keyword argument '%s' at %L is already associated "
1207 "with another actual argument", a->name, &a->expr->where);
1216 ("More actual than formal arguments in procedure call at %L",
1222 if (f->sym == NULL && a->expr == NULL)
1229 ("Missing alternate return spec in subroutine call at %L",
1234 if (a->expr == NULL)
1238 ("Unexpected alternate return spec in subroutine call at %L",
1243 if (!compare_parameter
1244 (f->sym, a->expr, ranks_must_agree, is_elemental))
1247 gfc_error ("Type/rank mismatch in argument '%s' at %L",
1248 f->sym->name, &a->expr->where);
1253 && f->sym->as->type == AS_ASSUMED_SHAPE
1254 && a->expr->expr_type == EXPR_VARIABLE
1255 && a->expr->symtree->n.sym->as
1256 && a->expr->symtree->n.sym->as->type == AS_ASSUMED_SIZE
1257 && (a->expr->ref == NULL
1258 || (a->expr->ref->type == REF_ARRAY
1259 && a->expr->ref->u.ar.type == AR_FULL)))
1262 gfc_error ("Actual argument for '%s' cannot be an assumed-size"
1263 " array at %L", f->sym->name, where);
1267 if (a->expr->expr_type != EXPR_NULL
1268 && compare_pointer (f->sym, a->expr) == 0)
1271 gfc_error ("Actual argument for '%s' must be a pointer at %L",
1272 f->sym->name, &a->expr->where);
1283 /* Make sure missing actual arguments are optional. */
1285 for (f = formal; f; f = f->next, i++)
1289 if (!f->sym->attr.optional)
1292 gfc_error ("Missing actual argument for argument '%s' at %L",
1293 f->sym->name, where);
1298 /* The argument lists are compatible. We now relink a new actual
1299 argument list with null arguments in the right places. The head
1300 of the list remains the head. */
1301 for (i = 0; i < n; i++)
1303 new[i] = gfc_get_actual_arglist ();
1316 for (i = 0; i < n - 1; i++)
1317 new[i]->next = new[i + 1];
1319 new[i]->next = NULL;
1321 if (*ap == NULL && n > 0)
1324 /* Note the types of omitted optional arguments. */
1325 for (a = actual, f = formal; a; a = a->next, f = f->next)
1326 if (a->expr == NULL && a->label == NULL)
1327 a->missing_arg_type = f->sym->ts.type;
1335 gfc_formal_arglist *f;
1336 gfc_actual_arglist *a;
1340 /* qsort comparison function for argument pairs, with the following
1342 - p->a->expr == NULL
1343 - p->a->expr->expr_type != EXPR_VARIABLE
1344 - growing p->a->expr->symbol. */
1347 pair_cmp (const void *p1, const void *p2)
1349 const gfc_actual_arglist *a1, *a2;
1351 /* *p1 and *p2 are elements of the to-be-sorted array. */
1352 a1 = ((const argpair *) p1)->a;
1353 a2 = ((const argpair *) p2)->a;
1362 if (a1->expr->expr_type != EXPR_VARIABLE)
1364 if (a2->expr->expr_type != EXPR_VARIABLE)
1368 if (a2->expr->expr_type != EXPR_VARIABLE)
1370 return a1->expr->symtree->n.sym < a2->expr->symtree->n.sym;
1374 /* Given two expressions from some actual arguments, test whether they
1375 refer to the same expression. The analysis is conservative.
1376 Returning FAILURE will produce no warning. */
1379 compare_actual_expr (gfc_expr * e1, gfc_expr * e2)
1381 const gfc_ref *r1, *r2;
1384 || e1->expr_type != EXPR_VARIABLE
1385 || e2->expr_type != EXPR_VARIABLE
1386 || e1->symtree->n.sym != e2->symtree->n.sym)
1389 /* TODO: improve comparison, see expr.c:show_ref(). */
1390 for (r1 = e1->ref, r2 = e2->ref; r1 && r2; r1 = r1->next, r2 = r2->next)
1392 if (r1->type != r2->type)
1397 if (r1->u.ar.type != r2->u.ar.type)
1399 /* TODO: At the moment, consider only full arrays;
1400 we could do better. */
1401 if (r1->u.ar.type != AR_FULL || r2->u.ar.type != AR_FULL)
1406 if (r1->u.c.component != r2->u.c.component)
1414 gfc_internal_error ("compare_actual_expr(): Bad component code");
1422 /* Given formal and actual argument lists that correspond to one
1423 another, check that identical actual arguments aren't not
1424 associated with some incompatible INTENTs. */
1427 check_some_aliasing (gfc_formal_arglist * f, gfc_actual_arglist * a)
1429 sym_intent f1_intent, f2_intent;
1430 gfc_formal_arglist *f1;
1431 gfc_actual_arglist *a1;
1437 for (f1 = f, a1 = a;; f1 = f1->next, a1 = a1->next)
1439 if (f1 == NULL && a1 == NULL)
1441 if (f1 == NULL || a1 == NULL)
1442 gfc_internal_error ("check_some_aliasing(): List mismatch");
1447 p = (argpair *) alloca (n * sizeof (argpair));
1449 for (i = 0, f1 = f, a1 = a; i < n; i++, f1 = f1->next, a1 = a1->next)
1455 qsort (p, n, sizeof (argpair), pair_cmp);
1457 for (i = 0; i < n; i++)
1460 || p[i].a->expr->expr_type != EXPR_VARIABLE
1461 || p[i].a->expr->ts.type == BT_PROCEDURE)
1463 f1_intent = p[i].f->sym->attr.intent;
1464 for (j = i + 1; j < n; j++)
1466 /* Expected order after the sort. */
1467 if (!p[j].a->expr || p[j].a->expr->expr_type != EXPR_VARIABLE)
1468 gfc_internal_error ("check_some_aliasing(): corrupted data");
1470 /* Are the expression the same? */
1471 if (compare_actual_expr (p[i].a->expr, p[j].a->expr) == FAILURE)
1473 f2_intent = p[j].f->sym->attr.intent;
1474 if ((f1_intent == INTENT_IN && f2_intent == INTENT_OUT)
1475 || (f1_intent == INTENT_OUT && f2_intent == INTENT_IN))
1477 gfc_warning ("Same actual argument associated with INTENT(%s) "
1478 "argument '%s' and INTENT(%s) argument '%s' at %L",
1479 gfc_intent_string (f1_intent), p[i].f->sym->name,
1480 gfc_intent_string (f2_intent), p[j].f->sym->name,
1481 &p[i].a->expr->where);
1491 /* Given formal and actual argument lists that correspond to one
1492 another, check that they are compatible in the sense that intents
1493 are not mismatched. */
1496 check_intents (gfc_formal_arglist * f, gfc_actual_arglist * a)
1498 sym_intent a_intent, f_intent;
1500 for (;; f = f->next, a = a->next)
1502 if (f == NULL && a == NULL)
1504 if (f == NULL || a == NULL)
1505 gfc_internal_error ("check_intents(): List mismatch");
1507 if (a->expr == NULL || a->expr->expr_type != EXPR_VARIABLE)
1510 a_intent = a->expr->symtree->n.sym->attr.intent;
1511 f_intent = f->sym->attr.intent;
1513 if (a_intent == INTENT_IN
1514 && (f_intent == INTENT_INOUT
1515 || f_intent == INTENT_OUT))
1518 gfc_error ("Procedure argument at %L is INTENT(IN) while interface "
1519 "specifies INTENT(%s)", &a->expr->where,
1520 gfc_intent_string (f_intent));
1524 if (gfc_pure (NULL) && gfc_impure_variable (a->expr->symtree->n.sym))
1526 if (f_intent == INTENT_INOUT || f_intent == INTENT_OUT)
1529 ("Procedure argument at %L is local to a PURE procedure and "
1530 "is passed to an INTENT(%s) argument", &a->expr->where,
1531 gfc_intent_string (f_intent));
1535 if (a->expr->symtree->n.sym->attr.pointer)
1538 ("Procedure argument at %L is local to a PURE procedure and "
1539 "has the POINTER attribute", &a->expr->where);
1549 /* Check how a procedure is used against its interface. If all goes
1550 well, the actual argument list will also end up being properly
1554 gfc_procedure_use (gfc_symbol * sym, gfc_actual_arglist ** ap, locus * where)
1556 /* Warn about calls with an implicit interface. */
1557 if (gfc_option.warn_implicit_interface
1558 && sym->attr.if_source == IFSRC_UNKNOWN)
1559 gfc_warning ("Procedure '%s' called with an implicit interface at %L",
1562 if (sym->attr.if_source == IFSRC_UNKNOWN
1563 || !compare_actual_formal (ap, sym->formal, 0,
1564 sym->attr.elemental, where))
1567 check_intents (sym->formal, *ap);
1568 if (gfc_option.warn_aliasing)
1569 check_some_aliasing (sym->formal, *ap);
1573 /* Given an interface pointer and an actual argument list, search for
1574 a formal argument list that matches the actual. If found, returns
1575 a pointer to the symbol of the correct interface. Returns NULL if
1579 gfc_search_interface (gfc_interface * intr, int sub_flag,
1580 gfc_actual_arglist ** ap)
1584 for (; intr; intr = intr->next)
1586 if (sub_flag && intr->sym->attr.function)
1588 if (!sub_flag && intr->sym->attr.subroutine)
1591 r = !intr->sym->attr.elemental;
1593 if (compare_actual_formal (ap, intr->sym->formal, r, !r, NULL))
1595 check_intents (intr->sym->formal, *ap);
1596 if (gfc_option.warn_aliasing)
1597 check_some_aliasing (intr->sym->formal, *ap);
1606 /* Do a brute force recursive search for a symbol. */
1608 static gfc_symtree *
1609 find_symtree0 (gfc_symtree * root, gfc_symbol * sym)
1613 if (root->n.sym == sym)
1618 st = find_symtree0 (root->left, sym);
1619 if (root->right && ! st)
1620 st = find_symtree0 (root->right, sym);
1625 /* Find a symtree for a symbol. */
1627 static gfc_symtree *
1628 find_sym_in_symtree (gfc_symbol * sym)
1633 /* First try to find it by name. */
1634 gfc_find_sym_tree (sym->name, gfc_current_ns, 1, &st);
1635 if (st && st->n.sym == sym)
1638 /* if it's been renamed, resort to a brute-force search. */
1639 /* TODO: avoid having to do this search. If the symbol doesn't exist
1640 in the symtree for the current namespace, it should probably be added. */
1641 for (ns = gfc_current_ns; ns; ns = ns->parent)
1643 st = find_symtree0 (ns->sym_root, sym);
1647 gfc_internal_error ("Unable to find symbol %s", sym->name);
1652 /* This subroutine is called when an expression is being resolved.
1653 The expression node in question is either a user defined operator
1654 or an intrinsic operator with arguments that aren't compatible
1655 with the operator. This subroutine builds an actual argument list
1656 corresponding to the operands, then searches for a compatible
1657 interface. If one is found, the expression node is replaced with
1658 the appropriate function call. */
1661 gfc_extend_expr (gfc_expr * e)
1663 gfc_actual_arglist *actual;
1671 actual = gfc_get_actual_arglist ();
1672 actual->expr = e->value.op.op1;
1674 if (e->value.op.op2 != NULL)
1676 actual->next = gfc_get_actual_arglist ();
1677 actual->next->expr = e->value.op.op2;
1680 i = fold_unary (e->value.op.operator);
1682 if (i == INTRINSIC_USER)
1684 for (ns = gfc_current_ns; ns; ns = ns->parent)
1686 uop = gfc_find_uop (e->value.op.uop->name, ns);
1690 sym = gfc_search_interface (uop->operator, 0, &actual);
1697 for (ns = gfc_current_ns; ns; ns = ns->parent)
1699 sym = gfc_search_interface (ns->operator[i], 0, &actual);
1707 /* Don't use gfc_free_actual_arglist() */
1708 if (actual->next != NULL)
1709 gfc_free (actual->next);
1715 /* Change the expression node to a function call. */
1716 e->expr_type = EXPR_FUNCTION;
1717 e->symtree = find_sym_in_symtree (sym);
1718 e->value.function.actual = actual;
1719 e->value.function.esym = NULL;
1720 e->value.function.isym = NULL;
1722 if (gfc_pure (NULL) && !gfc_pure (sym))
1725 ("Function '%s' called in lieu of an operator at %L must be PURE",
1726 sym->name, &e->where);
1730 if (gfc_resolve_expr (e) == FAILURE)
1737 /* Tries to replace an assignment code node with a subroutine call to
1738 the subroutine associated with the assignment operator. Return
1739 SUCCESS if the node was replaced. On FAILURE, no error is
1743 gfc_extend_assign (gfc_code * c, gfc_namespace * ns)
1745 gfc_actual_arglist *actual;
1746 gfc_expr *lhs, *rhs;
1752 /* Don't allow an intrinsic assignment to be replaced. */
1753 if (lhs->ts.type != BT_DERIVED && rhs->ts.type != BT_DERIVED
1754 && (lhs->ts.type == rhs->ts.type
1755 || (gfc_numeric_ts (&lhs->ts)
1756 && gfc_numeric_ts (&rhs->ts))))
1759 actual = gfc_get_actual_arglist ();
1762 actual->next = gfc_get_actual_arglist ();
1763 actual->next->expr = rhs;
1767 for (; ns; ns = ns->parent)
1769 sym = gfc_search_interface (ns->operator[INTRINSIC_ASSIGN], 1, &actual);
1776 gfc_free (actual->next);
1781 /* Replace the assignment with the call. */
1783 c->symtree = find_sym_in_symtree (sym);
1786 c->ext.actual = actual;
1788 if (gfc_pure (NULL) && !gfc_pure (sym))
1790 gfc_error ("Subroutine '%s' called in lieu of assignment at %L must be "
1791 "PURE", sym->name, &c->loc);
1799 /* Make sure that the interface just parsed is not already present in
1800 the given interface list. Ambiguity isn't checked yet since module
1801 procedures can be present without interfaces. */
1804 check_new_interface (gfc_interface * base, gfc_symbol * new)
1808 for (ip = base; ip; ip = ip->next)
1812 gfc_error ("Entity '%s' at %C is already present in the interface",
1822 /* Add a symbol to the current interface. */
1825 gfc_add_interface (gfc_symbol * new)
1827 gfc_interface **head, *intr;
1831 switch (current_interface.type)
1833 case INTERFACE_NAMELESS:
1836 case INTERFACE_INTRINSIC_OP:
1837 for (ns = current_interface.ns; ns; ns = ns->parent)
1838 if (check_new_interface (ns->operator[current_interface.op], new)
1842 head = ¤t_interface.ns->operator[current_interface.op];
1845 case INTERFACE_GENERIC:
1846 for (ns = current_interface.ns; ns; ns = ns->parent)
1848 gfc_find_symbol (current_interface.sym->name, ns, 0, &sym);
1852 if (check_new_interface (sym->generic, new) == FAILURE)
1856 head = ¤t_interface.sym->generic;
1859 case INTERFACE_USER_OP:
1860 if (check_new_interface (current_interface.uop->operator, new) ==
1864 head = ¤t_interface.uop->operator;
1868 gfc_internal_error ("gfc_add_interface(): Bad interface type");
1871 intr = gfc_get_interface ();
1873 intr->where = gfc_current_locus;
1882 /* Gets rid of a formal argument list. We do not free symbols.
1883 Symbols are freed when a namespace is freed. */
1886 gfc_free_formal_arglist (gfc_formal_arglist * p)
1888 gfc_formal_arglist *q;