/* Maintain binary trees of symbols. Copyright (C) 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc. Contributed by Andy Vaught This file is part of GCC. GCC is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GCC is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GCC; see the file COPYING. If not, write to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include "config.h" #include #include #include #include "gfortran.h" #include "parse.h" /* Strings for all symbol attributes. We use these for dumping the parse tree, in error messages, and also when reading and writing modules. */ const mstring flavors[] = { minit ("UNKNOWN-FL", FL_UNKNOWN), minit ("PROGRAM", FL_PROGRAM), minit ("BLOCK-DATA", FL_BLOCK_DATA), minit ("MODULE", FL_MODULE), minit ("VARIABLE", FL_VARIABLE), minit ("PARAMETER", FL_PARAMETER), minit ("LABEL", FL_LABEL), minit ("PROCEDURE", FL_PROCEDURE), minit ("DERIVED", FL_DERIVED), minit ("NAMELIST", FL_NAMELIST), minit (NULL, -1) }; const mstring procedures[] = { minit ("UNKNOWN-PROC", PROC_UNKNOWN), minit ("MODULE-PROC", PROC_MODULE), minit ("INTERNAL-PROC", PROC_INTERNAL), minit ("DUMMY-PROC", PROC_DUMMY), minit ("INTRINSIC-PROC", PROC_INTRINSIC), minit ("EXTERNAL-PROC", PROC_EXTERNAL), minit ("STATEMENT-PROC", PROC_ST_FUNCTION), minit (NULL, -1) }; const mstring intents[] = { minit ("UNKNOWN-INTENT", INTENT_UNKNOWN), minit ("IN", INTENT_IN), minit ("OUT", INTENT_OUT), minit ("INOUT", INTENT_INOUT), minit (NULL, -1) }; const mstring access_types[] = { minit ("UNKNOWN-ACCESS", ACCESS_UNKNOWN), minit ("PUBLIC", ACCESS_PUBLIC), minit ("PRIVATE", ACCESS_PRIVATE), minit (NULL, -1) }; const mstring ifsrc_types[] = { minit ("UNKNOWN", IFSRC_UNKNOWN), minit ("DECL", IFSRC_DECL), minit ("BODY", IFSRC_IFBODY), minit ("USAGE", IFSRC_USAGE) }; /* This is to make sure the backend generates setup code in the correct order. */ static int next_dummy_order = 1; gfc_namespace *gfc_current_ns; gfc_gsymbol *gfc_gsym_root = NULL; static gfc_symbol *changed_syms = NULL; /*********** IMPLICIT NONE and IMPLICIT statement handlers ***********/ /* The following static variables hold the default types set by IMPLICIT statements. We have to store kind information because of IMPLICIT DOUBLE PRECISION statements. IMPLICIT NONE stores a BT_UNKNOWN into all elements. The arrays of flags indicate whether a particular element has been explicitly set or not. */ static gfc_typespec new_ts[GFC_LETTERS]; static int new_flag[GFC_LETTERS]; /* Handle a correctly parsed IMPLICIT NONE. */ void gfc_set_implicit_none (void) { int i; for (i = 'a'; i <= 'z'; i++) { gfc_clear_ts (&gfc_current_ns->default_type[i - 'a']); gfc_current_ns->set_flag[i - 'a'] = 1; } } /* Sets the implicit types parsed by gfc_match_implicit(). */ void gfc_set_implicit (void) { int i; for (i = 0; i < GFC_LETTERS; i++) if (new_flag[i]) { gfc_current_ns->default_type[i] = new_ts[i]; gfc_current_ns->set_flag[i] = 1; } } /* Wipe anything a previous IMPLICIT statement may have tried to do. */ void gfc_clear_new_implicit (void) { int i; for (i = 0; i < GFC_LETTERS; i++) { gfc_clear_ts (&new_ts[i]); if (new_flag[i]) new_flag[i] = 0; } } /* Prepare for a new implicit range. Sets flags in new_flag[] and copies the typespec to new_ts[]. */ try gfc_add_new_implicit_range (int c1, int c2, gfc_typespec * ts) { int i; c1 -= 'a'; c2 -= 'a'; for (i = c1; i <= c2; i++) { if (new_flag[i]) { gfc_error ("Letter '%c' already set in IMPLICIT statement at %C", i + 'A'); return FAILURE; } new_ts[i] = *ts; new_flag[i] = 1; } return SUCCESS; } /* Add a matched implicit range for gfc_set_implicit(). An implicit statement has been fully matched at this point. We now need to check if merging the new implicit types back into the existing types will work. */ try gfc_merge_new_implicit (void) { int i; for (i = 0; i < GFC_LETTERS; i++) if (new_flag[i]) { if (gfc_current_ns->set_flag[i]) { gfc_error ("Letter %c already has an IMPLICIT type at %C", i + 'A'); return FAILURE; } } return SUCCESS; } /* Given a symbol, return a pointer to the typespec for it's default type. */ gfc_typespec * gfc_get_default_type (gfc_symbol * sym, gfc_namespace * ns) { char letter; letter = sym->name[0]; if (letter < 'a' || letter > 'z') gfc_internal_error ("gfc_get_default_type(): Bad symbol"); if (ns == NULL) ns = gfc_current_ns; return &ns->default_type[letter - 'a']; } /* Given a pointer to a symbol, set its type according to the first letter of its name. Fails if the letter in question has no default type. */ try gfc_set_default_type (gfc_symbol * sym, int error_flag, gfc_namespace * ns) { gfc_typespec *ts; if (sym->ts.type != BT_UNKNOWN) gfc_internal_error ("gfc_set_default_type(): symbol already has a type"); ts = gfc_get_default_type (sym, ns); if (ts->type == BT_UNKNOWN) { if (error_flag) gfc_error ("Symbol '%s' at %L has no IMPLICIT type", sym->name, &sym->declared_at); return FAILURE; } sym->ts = *ts; sym->attr.implicit_type = 1; return SUCCESS; } /******************** Symbol attribute stuff *********************/ /* This is a generic conflict-checker. We do this to avoid having a single conflict in two places. */ #define conf(a, b) if (attr->a && attr->b) { a1 = a; a2 = b; goto conflict; } #define conf2(a) if (attr->a) { a2 = a; goto conflict; } static try check_conflict (symbol_attribute * attr, locus * where) { static const char *dummy = "DUMMY", *save = "SAVE", *pointer = "POINTER", *target = "TARGET", *external = "EXTERNAL", *intent = "INTENT", *intrinsic = "INTRINSIC", *allocatable = "ALLOCATABLE", *elemental = "ELEMENTAL", *private = "PRIVATE", *recursive = "RECURSIVE", *in_common = "COMMON", *result = "RESULT", *in_namelist = "NAMELIST", *public = "PUBLIC", *optional = "OPTIONAL", *entry = "ENTRY", *function = "FUNCTION", *subroutine = "SUBROUTINE", *dimension = "DIMENSION"; const char *a1, *a2; if (where == NULL) where = &gfc_current_locus; if (attr->pointer && attr->intent != INTENT_UNKNOWN) { a1 = pointer; a2 = intent; goto conflict; } /* Check for attributes not allowed in a BLOCK DATA. */ if (gfc_current_state () == COMP_BLOCK_DATA) { a1 = NULL; if (attr->allocatable) a1 = allocatable; if (attr->external) a1 = external; if (attr->optional) a1 = optional; if (attr->access == ACCESS_PRIVATE) a1 = private; if (attr->access == ACCESS_PUBLIC) a1 = public; if (attr->intent != INTENT_UNKNOWN) a1 = intent; if (a1 != NULL) { gfc_error ("%s attribute not allowed in BLOCK DATA program unit at %L", a1, where); return FAILURE; } } conf (dummy, save); conf (pointer, target); conf (pointer, external); conf (pointer, intrinsic); conf (target, external); conf (target, intrinsic); conf (external, dimension); /* See Fortran 95's R504. */ conf (external, intrinsic); conf (allocatable, pointer); conf (allocatable, dummy); /* TODO: Allowed in Fortran 200x. */ conf (allocatable, function); /* TODO: Allowed in Fortran 200x. */ conf (allocatable, result); /* TODO: Allowed in Fortran 200x. */ conf (elemental, recursive); conf (in_common, dummy); conf (in_common, allocatable); conf (in_common, result); conf (dummy, result); conf (in_namelist, pointer); conf (in_namelist, allocatable); conf (entry, result); conf (function, subroutine); a1 = gfc_code2string (flavors, attr->flavor); if (attr->in_namelist && attr->flavor != FL_VARIABLE && attr->flavor != FL_UNKNOWN) { a2 = in_namelist; goto conflict; } switch (attr->flavor) { case FL_PROGRAM: case FL_BLOCK_DATA: case FL_MODULE: case FL_LABEL: conf2 (dummy); conf2 (save); conf2 (pointer); conf2 (target); conf2 (external); conf2 (intrinsic); conf2 (allocatable); conf2 (result); conf2 (in_namelist); conf2 (optional); conf2 (function); conf2 (subroutine); break; case FL_VARIABLE: case FL_NAMELIST: break; case FL_PROCEDURE: conf2 (intent); if (attr->subroutine) { conf2(save); conf2(pointer); conf2(target); conf2(allocatable); conf2(result); conf2(in_namelist); conf2(function); } switch (attr->proc) { case PROC_ST_FUNCTION: conf2 (in_common); break; case PROC_MODULE: conf2 (dummy); break; case PROC_DUMMY: conf2 (result); conf2 (in_common); conf2 (save); break; default: break; } break; case FL_DERIVED: conf2 (dummy); conf2 (save); conf2 (pointer); conf2 (target); conf2 (external); conf2 (intrinsic); conf2 (allocatable); conf2 (optional); conf2 (entry); conf2 (function); conf2 (subroutine); if (attr->intent != INTENT_UNKNOWN) { a2 = intent; goto conflict; } break; case FL_PARAMETER: conf2 (external); conf2 (intrinsic); conf2 (optional); conf2 (allocatable); conf2 (function); conf2 (subroutine); conf2 (entry); conf2 (pointer); conf2 (target); conf2 (dummy); conf2 (in_common); break; default: break; } return SUCCESS; conflict: gfc_error ("%s attribute conflicts with %s attribute at %L", a1, a2, where); return FAILURE; } #undef conf #undef conf2 /* Mark a symbol as referenced. */ void gfc_set_sym_referenced (gfc_symbol * sym) { if (sym->attr.referenced) return; sym->attr.referenced = 1; /* Remember which order dummy variables are accessed in. */ if (sym->attr.dummy) sym->dummy_order = next_dummy_order++; } /* Common subroutine called by attribute changing subroutines in order to prevent them from changing a symbol that has been use-associated. Returns zero if it is OK to change the symbol, nonzero if not. */ static int check_used (symbol_attribute * attr, locus * where) { if (attr->use_assoc == 0) return 0; if (where == NULL) where = &gfc_current_locus; gfc_error ("Cannot change attributes of USE-associated symbol at %L", where); return 1; } /* Used to prevent changing the attributes of a symbol after it has been used. This check is only done from dummy variable as only these can be used in specification expressions. Applying this to all symbols causes error when we reach the body of a contained function. */ static int check_done (symbol_attribute * attr, locus * where) { if (!(attr->dummy && attr->referenced)) return 0; if (where == NULL) where = &gfc_current_locus; gfc_error ("Cannot change attributes of symbol at %L" " after it has been used", where); return 1; } /* Generate an error because of a duplicate attribute. */ static void duplicate_attr (const char *attr, locus * where) { if (where == NULL) where = &gfc_current_locus; gfc_error ("Duplicate %s attribute specified at %L", attr, where); } try gfc_add_allocatable (symbol_attribute * attr, locus * where) { if (check_used (attr, where) || check_done (attr, where)) return FAILURE; if (attr->allocatable) { duplicate_attr ("ALLOCATABLE", where); return FAILURE; } attr->allocatable = 1; return check_conflict (attr, where); } try gfc_add_dimension (symbol_attribute * attr, locus * where) { if (check_used (attr, where) || check_done (attr, where)) return FAILURE; if (attr->dimension) { duplicate_attr ("DIMENSION", where); return FAILURE; } attr->dimension = 1; return check_conflict (attr, where); } try gfc_add_external (symbol_attribute * attr, locus * where) { if (check_used (attr, where) || check_done (attr, where)) return FAILURE; if (attr->external) { duplicate_attr ("EXTERNAL", where); return FAILURE; } attr->external = 1; return check_conflict (attr, where); } try gfc_add_intrinsic (symbol_attribute * attr, locus * where) { if (check_used (attr, where) || check_done (attr, where)) return FAILURE; if (attr->intrinsic) { duplicate_attr ("INTRINSIC", where); return FAILURE; } attr->intrinsic = 1; return check_conflict (attr, where); } try gfc_add_optional (symbol_attribute * attr, locus * where) { if (check_used (attr, where) || check_done (attr, where)) return FAILURE; if (attr->optional) { duplicate_attr ("OPTIONAL", where); return FAILURE; } attr->optional = 1; return check_conflict (attr, where); } try gfc_add_pointer (symbol_attribute * attr, locus * where) { if (check_used (attr, where) || check_done (attr, where)) return FAILURE; attr->pointer = 1; return check_conflict (attr, where); } try gfc_add_result (symbol_attribute * attr, locus * where) { if (check_used (attr, where) || check_done (attr, where)) return FAILURE; attr->result = 1; return check_conflict (attr, where); } try gfc_add_save (symbol_attribute * attr, locus * where) { if (check_used (attr, where)) return FAILURE; if (gfc_pure (NULL)) { gfc_error ("SAVE attribute at %L cannot be specified in a PURE procedure", where); return FAILURE; } if (attr->save) { duplicate_attr ("SAVE", where); return FAILURE; } attr->save = 1; return check_conflict (attr, where); } try gfc_add_target (symbol_attribute * attr, locus * where) { if (check_used (attr, where) || check_done (attr, where)) return FAILURE; if (attr->target) { duplicate_attr ("TARGET", where); return FAILURE; } attr->target = 1; return check_conflict (attr, where); } try gfc_add_dummy (symbol_attribute * attr, locus * where) { if (check_used (attr, where)) return FAILURE; /* Duplicate dummy arguments are allow due to ENTRY statements. */ attr->dummy = 1; return check_conflict (attr, where); } try gfc_add_in_common (symbol_attribute * attr, locus * where) { if (check_used (attr, where) || check_done (attr, where)) return FAILURE; /* Duplicate attribute already checked for. */ attr->in_common = 1; if (check_conflict (attr, where) == FAILURE) return FAILURE; if (attr->flavor == FL_VARIABLE) return SUCCESS; return gfc_add_flavor (attr, FL_VARIABLE, where); } try gfc_add_data (symbol_attribute *attr, locus *where) { if (check_used (attr, where)) return FAILURE; attr->data = 1; return check_conflict (attr, where); } try gfc_add_in_namelist (symbol_attribute * attr, locus * where) { attr->in_namelist = 1; return check_conflict (attr, where); } try gfc_add_sequence (symbol_attribute * attr, locus * where) { if (check_used (attr, where)) return FAILURE; attr->sequence = 1; return check_conflict (attr, where); } try gfc_add_elemental (symbol_attribute * attr, locus * where) { if (check_used (attr, where) || check_done (attr, where)) return FAILURE; attr->elemental = 1; return check_conflict (attr, where); } try gfc_add_pure (symbol_attribute * attr, locus * where) { if (check_used (attr, where) || check_done (attr, where)) return FAILURE; attr->pure = 1; return check_conflict (attr, where); } try gfc_add_recursive (symbol_attribute * attr, locus * where) { if (check_used (attr, where) || check_done (attr, where)) return FAILURE; attr->recursive = 1; return check_conflict (attr, where); } try gfc_add_entry (symbol_attribute * attr, locus * where) { if (check_used (attr, where)) return FAILURE; if (attr->entry) { duplicate_attr ("ENTRY", where); return FAILURE; } attr->entry = 1; return check_conflict (attr, where); } try gfc_add_function (symbol_attribute * attr, locus * where) { if (attr->flavor != FL_PROCEDURE && gfc_add_flavor (attr, FL_PROCEDURE, where) == FAILURE) return FAILURE; attr->function = 1; return check_conflict (attr, where); } try gfc_add_subroutine (symbol_attribute * attr, locus * where) { if (attr->flavor != FL_PROCEDURE && gfc_add_flavor (attr, FL_PROCEDURE, where) == FAILURE) return FAILURE; attr->subroutine = 1; return check_conflict (attr, where); } try gfc_add_generic (symbol_attribute * attr, locus * where) { if (attr->flavor != FL_PROCEDURE && gfc_add_flavor (attr, FL_PROCEDURE, where) == FAILURE) return FAILURE; attr->generic = 1; return check_conflict (attr, where); } /* Flavors are special because some flavors are not what fortran considers attributes and can be reaffirmed multiple times. */ try gfc_add_flavor (symbol_attribute * attr, sym_flavor f, locus * where) { if ((f == FL_PROGRAM || f == FL_BLOCK_DATA || f == FL_MODULE || f == FL_PARAMETER || f == FL_LABEL || f == FL_DERIVED || f == FL_NAMELIST) && check_used (attr, where)) return FAILURE; if (attr->flavor == f && f == FL_VARIABLE) return SUCCESS; if (attr->flavor != FL_UNKNOWN) { if (where == NULL) where = &gfc_current_locus; gfc_error ("%s attribute conflicts with %s attribute at %L", gfc_code2string (flavors, attr->flavor), gfc_code2string (flavors, f), where); return FAILURE; } attr->flavor = f; return check_conflict (attr, where); } try gfc_add_procedure (symbol_attribute * attr, procedure_type t, locus * where) { if (check_used (attr, where) || check_done (attr, where)) return FAILURE; if (attr->flavor != FL_PROCEDURE && gfc_add_flavor (attr, FL_PROCEDURE, where) == FAILURE) return FAILURE; if (where == NULL) where = &gfc_current_locus; if (attr->proc != PROC_UNKNOWN) { gfc_error ("%s procedure at %L is already %s %s procedure", gfc_code2string (procedures, t), where, gfc_article (gfc_code2string (procedures, attr->proc)), gfc_code2string (procedures, attr->proc)); return FAILURE; } attr->proc = t; /* Statement functions are always scalar and functions. */ if (t == PROC_ST_FUNCTION && ((!attr->function && gfc_add_function (attr, where) == FAILURE) || attr->dimension)) return FAILURE; return check_conflict (attr, where); } try gfc_add_intent (symbol_attribute * attr, sym_intent intent, locus * where) { if (check_used (attr, where)) return FAILURE; if (attr->intent == INTENT_UNKNOWN) { attr->intent = intent; return check_conflict (attr, where); } if (where == NULL) where = &gfc_current_locus; gfc_error ("INTENT (%s) conflicts with INTENT(%s) at %L", gfc_intent_string (attr->intent), gfc_intent_string (intent), where); return FAILURE; } /* No checks for use-association in public and private statements. */ try gfc_add_access (symbol_attribute * attr, gfc_access access, locus * where) { if (attr->access == ACCESS_UNKNOWN) { attr->access = access; return check_conflict (attr, where); } if (where == NULL) where = &gfc_current_locus; gfc_error ("ACCESS specification at %L was already specified", where); return FAILURE; } try gfc_add_explicit_interface (gfc_symbol * sym, ifsrc source, gfc_formal_arglist * formal, locus * where) { if (check_used (&sym->attr, where)) return FAILURE; if (where == NULL) where = &gfc_current_locus; if (sym->attr.if_source != IFSRC_UNKNOWN && sym->attr.if_source != IFSRC_DECL) { gfc_error ("Symbol '%s' at %L already has an explicit interface", sym->name, where); return FAILURE; } sym->formal = formal; sym->attr.if_source = source; return SUCCESS; } /* Add a type to a symbol. */ try gfc_add_type (gfc_symbol * sym, gfc_typespec * ts, locus * where) { sym_flavor flavor; /* TODO: This is legal if it is reaffirming an implicit type. if (check_done (&sym->attr, where)) return FAILURE;*/ if (where == NULL) where = &gfc_current_locus; if (sym->ts.type != BT_UNKNOWN) { gfc_error ("Symbol '%s' at %L already has basic type of %s", sym->name, where, gfc_basic_typename (sym->ts.type)); return FAILURE; } flavor = sym->attr.flavor; if (flavor == FL_PROGRAM || flavor == FL_BLOCK_DATA || flavor == FL_MODULE || flavor == FL_LABEL || (flavor == FL_PROCEDURE && sym->attr.subroutine) || flavor == FL_DERIVED || flavor == FL_NAMELIST) { gfc_error ("Symbol '%s' at %L cannot have a type", sym->name, where); return FAILURE; } sym->ts = *ts; return SUCCESS; } /* Clears all attributes. */ void gfc_clear_attr (symbol_attribute * attr) { attr->allocatable = 0; attr->dimension = 0; attr->external = 0; attr->intrinsic = 0; attr->optional = 0; attr->pointer = 0; attr->save = 0; attr->target = 0; attr->dummy = 0; attr->result = 0; attr->entry = 0; attr->data = 0; attr->use_assoc = 0; attr->in_namelist = 0; attr->in_common = 0; attr->function = 0; attr->subroutine = 0; attr->generic = 0; attr->implicit_type = 0; attr->sequence = 0; attr->elemental = 0; attr->pure = 0; attr->recursive = 0; attr->access = ACCESS_UNKNOWN; attr->intent = INTENT_UNKNOWN; attr->flavor = FL_UNKNOWN; attr->proc = PROC_UNKNOWN; attr->if_source = IFSRC_UNKNOWN; } /* Check for missing attributes in the new symbol. Currently does nothing, but it's not clear that it is unnecessary yet. */ try gfc_missing_attr (symbol_attribute * attr ATTRIBUTE_UNUSED, locus * where ATTRIBUTE_UNUSED) { return SUCCESS; } /* Copy an attribute to a symbol attribute, bit by bit. Some attributes have a lot of side-effects but cannot be present given where we are called from, so we ignore some bits. */ try gfc_copy_attr (symbol_attribute * dest, symbol_attribute * src, locus * where) { if (src->allocatable && gfc_add_allocatable (dest, where) == FAILURE) goto fail; if (src->dimension && gfc_add_dimension (dest, where) == FAILURE) goto fail; if (src->optional && gfc_add_optional (dest, where) == FAILURE) goto fail; if (src->pointer && gfc_add_pointer (dest, where) == FAILURE) goto fail; if (src->save && gfc_add_save (dest, where) == FAILURE) goto fail; if (src->target && gfc_add_target (dest, where) == FAILURE) goto fail; if (src->dummy && gfc_add_dummy (dest, where) == FAILURE) goto fail; if (src->result && gfc_add_result (dest, where) == FAILURE) goto fail; if (src->entry) dest->entry = 1; if (src->in_namelist && gfc_add_in_namelist (dest, where) == FAILURE) goto fail; if (src->in_common && gfc_add_in_common (dest, where) == FAILURE) goto fail; if (src->generic && gfc_add_generic (dest, where) == FAILURE) goto fail; if (src->function && gfc_add_function (dest, where) == FAILURE) goto fail; if (src->subroutine && gfc_add_subroutine (dest, where) == FAILURE) goto fail; if (src->sequence && gfc_add_sequence (dest, where) == FAILURE) goto fail; if (src->elemental && gfc_add_elemental (dest, where) == FAILURE) goto fail; if (src->pure && gfc_add_pure (dest, where) == FAILURE) goto fail; if (src->recursive && gfc_add_recursive (dest, where) == FAILURE) goto fail; if (src->flavor != FL_UNKNOWN && gfc_add_flavor (dest, src->flavor, where) == FAILURE) goto fail; if (src->intent != INTENT_UNKNOWN && gfc_add_intent (dest, src->intent, where) == FAILURE) goto fail; if (src->access != ACCESS_UNKNOWN && gfc_add_access (dest, src->access, where) == FAILURE) goto fail; if (gfc_missing_attr (dest, where) == FAILURE) goto fail; /* The subroutines that set these bits also cause flavors to be set, and that has already happened in the original, so don't let to happen again. */ if (src->external) dest->external = 1; if (src->intrinsic) dest->intrinsic = 1; return SUCCESS; fail: return FAILURE; } /************** Component name management ************/ /* Component names of a derived type form their own little namespaces that are separate from all other spaces. The space is composed of a singly linked list of gfc_component structures whose head is located in the parent symbol. */ /* Add a component name to a symbol. The call fails if the name is already present. On success, the component pointer is modified to point to the additional component structure. */ try gfc_add_component (gfc_symbol * sym, const char *name, gfc_component ** component) { gfc_component *p, *tail; tail = NULL; for (p = sym->components; p; p = p->next) { if (strcmp (p->name, name) == 0) { gfc_error ("Component '%s' at %C already declared at %L", name, &p->loc); return FAILURE; } tail = p; } /* Allocate new component */ p = gfc_get_component (); if (tail == NULL) sym->components = p; else tail->next = p; strcpy (p->name, name); p->loc = gfc_current_locus; *component = p; return SUCCESS; } /* Recursive function to switch derived types of all symbol in a namespace. */ static void switch_types (gfc_symtree * st, gfc_symbol * from, gfc_symbol * to) { gfc_symbol *sym; if (st == NULL) return; sym = st->n.sym; if (sym->ts.type == BT_DERIVED && sym->ts.derived == from) sym->ts.derived = to; switch_types (st->left, from, to); switch_types (st->right, from, to); } /* This subroutine is called when a derived type is used in order to make the final determination about which version to use. The standard requires that a type be defined before it is 'used', but such types can appear in IMPLICIT statements before the actual definition. 'Using' in this context means declaring a variable to be that type or using the type constructor. If a type is used and the components haven't been defined, then we have to have a derived type in a parent unit. We find the node in the other namespace and point the symtree node in this namespace to that node. Further reference to this name point to the correct node. If we can't find the node in a parent namespace, then have an error. This subroutine takes a pointer to a symbol node and returns a pointer to the translated node or NULL for an error. Usually there is no translation and we return the node we were passed. */ static gfc_symtree * gfc_use_ha_derived (gfc_symbol * sym) { gfc_symbol *s, *p; gfc_typespec *t; gfc_symtree *st; int i; if (sym->ns->parent == NULL) goto bad; if (gfc_find_symbol (sym->name, sym->ns->parent, 1, &s)) { gfc_error ("Symbol '%s' at %C is ambiguous", sym->name); return NULL; } if (s == NULL || s->attr.flavor != FL_DERIVED) goto bad; /* Get rid of symbol sym, translating all references to s. */ for (i = 0; i < GFC_LETTERS; i++) { t = &sym->ns->default_type[i]; if (t->derived == sym) t->derived = s; } st = gfc_find_symtree (sym->ns->sym_root, sym->name); st->n.sym = s; s->refs++; /* Unlink from list of modified symbols. */ if (changed_syms == sym) changed_syms = sym->tlink; else for (p = changed_syms; p; p = p->tlink) if (p->tlink == sym) { p->tlink = sym->tlink; break; } switch_types (sym->ns->sym_root, sym, s); /* TODO: Also have to replace sym -> s in other lists like namelists, common lists and interface lists. */ gfc_free_symbol (sym); return st; bad: gfc_error ("Derived type '%s' at %C is being used before it is defined", sym->name); return NULL; } gfc_symbol * gfc_use_derived (gfc_symbol * sym) { gfc_symtree *st; if (sym->components != NULL) return sym; /* Already defined */ st = gfc_use_ha_derived (sym); if (st) return st->n.sym; else return NULL; } /* Given a derived type node and a component name, try to locate the component structure. Returns the NULL pointer if the component is not found or the components are private. */ gfc_component * gfc_find_component (gfc_symbol * sym, const char *name) { gfc_component *p; if (name == NULL) return NULL; sym = gfc_use_derived (sym); if (sym == NULL) return NULL; for (p = sym->components; p; p = p->next) if (strcmp (p->name, name) == 0) break; if (p == NULL) gfc_error ("'%s' at %C is not a member of the '%s' structure", name, sym->name); else { if (sym->attr.use_assoc && sym->component_access == ACCESS_PRIVATE) { gfc_error ("Component '%s' at %C is a PRIVATE component of '%s'", name, sym->name); p = NULL; } } return p; } /* Given a symbol, free all of the component structures and everything they point to. */ static void free_components (gfc_component * p) { gfc_component *q; for (; p; p = q) { q = p->next; gfc_free_array_spec (p->as); gfc_free_expr (p->initializer); gfc_free (p); } } /* Set component attributes from a standard symbol attribute structure. */ void gfc_set_component_attr (gfc_component * c, symbol_attribute * attr) { c->dimension = attr->dimension; c->pointer = attr->pointer; } /* Get a standard symbol attribute structure given the component structure. */ void gfc_get_component_attr (symbol_attribute * attr, gfc_component * c) { gfc_clear_attr (attr); attr->dimension = c->dimension; attr->pointer = c->pointer; } /******************** Statement label management ********************/ /* Free a single gfc_st_label structure, making sure the list is not messed up. This function is called only when some parse error occurs. */ void gfc_free_st_label (gfc_st_label * l) { if (l == NULL) return; if (l->prev) (l->prev->next = l->next); if (l->next) (l->next->prev = l->prev); if (l->format != NULL) gfc_free_expr (l->format); gfc_free (l); } /* Free a whole list of gfc_st_label structures. */ static void free_st_labels (gfc_st_label * l1) { gfc_st_label *l2; for (; l1; l1 = l2) { l2 = l1->next; if (l1->format != NULL) gfc_free_expr (l1->format); gfc_free (l1); } } /* Given a label number, search for and return a pointer to the label structure, creating it if it does not exist. */ gfc_st_label * gfc_get_st_label (int labelno) { gfc_st_label *lp; /* First see if the label is already in this namespace. */ for (lp = gfc_current_ns->st_labels; lp; lp = lp->next) if (lp->value == labelno) break; if (lp != NULL) return lp; lp = gfc_getmem (sizeof (gfc_st_label)); lp->value = labelno; lp->defined = ST_LABEL_UNKNOWN; lp->referenced = ST_LABEL_UNKNOWN; lp->prev = NULL; lp->next = gfc_current_ns->st_labels; if (gfc_current_ns->st_labels) gfc_current_ns->st_labels->prev = lp; gfc_current_ns->st_labels = lp; return lp; } /* Called when a statement with a statement label is about to be accepted. We add the label to the list of the current namespace, making sure it hasn't been defined previously and referenced correctly. */ void gfc_define_st_label (gfc_st_label * lp, gfc_sl_type type, locus * label_locus) { int labelno; labelno = lp->value; if (lp->defined != ST_LABEL_UNKNOWN) gfc_error ("Duplicate statement label %d at %L and %L", labelno, &lp->where, label_locus); else { lp->where = *label_locus; switch (type) { case ST_LABEL_FORMAT: if (lp->referenced == ST_LABEL_TARGET) gfc_error ("Label %d at %C already referenced as branch target", labelno); else lp->defined = ST_LABEL_FORMAT; break; case ST_LABEL_TARGET: if (lp->referenced == ST_LABEL_FORMAT) gfc_error ("Label %d at %C already referenced as a format label", labelno); else lp->defined = ST_LABEL_TARGET; break; default: lp->defined = ST_LABEL_BAD_TARGET; lp->referenced = ST_LABEL_BAD_TARGET; } } } /* Reference a label. Given a label and its type, see if that reference is consistent with what is known about that label, updating the unknown state. Returns FAILURE if something goes wrong. */ try gfc_reference_st_label (gfc_st_label * lp, gfc_sl_type type) { gfc_sl_type label_type; int labelno; try rc; if (lp == NULL) return SUCCESS; labelno = lp->value; if (lp->defined != ST_LABEL_UNKNOWN) label_type = lp->defined; else { label_type = lp->referenced; lp->where = gfc_current_locus; } if (label_type == ST_LABEL_FORMAT && type == ST_LABEL_TARGET) { gfc_error ("Label %d at %C previously used as a FORMAT label", labelno); rc = FAILURE; goto done; } if ((label_type == ST_LABEL_TARGET || label_type == ST_LABEL_BAD_TARGET) && type == ST_LABEL_FORMAT) { gfc_error ("Label %d at %C previously used as branch target", labelno); rc = FAILURE; goto done; } lp->referenced = type; rc = SUCCESS; done: return rc; } /************** Symbol table management subroutines ****************/ /* Basic details: Fortran 95 requires a potentially unlimited number of distinct namespaces when compiling a program unit. This case occurs during a compilation of internal subprograms because all of the internal subprograms must be read before we can start generating code for the host. Given the tricky nature of the fortran grammar, we must be able to undo changes made to a symbol table if the current interpretation of a statement is found to be incorrect. Whenever a symbol is looked up, we make a copy of it and link to it. All of these symbols are kept in a singly linked list so that we can commit or undo the changes at a later time. A symtree may point to a symbol node outside of it's namespace. In this case, that symbol has been used as a host associated variable at some previous time. */ /* Allocate a new namespace structure. */ gfc_namespace * gfc_get_namespace (gfc_namespace * parent) { gfc_namespace *ns; gfc_typespec *ts; gfc_intrinsic_op in; int i; ns = gfc_getmem (sizeof (gfc_namespace)); ns->sym_root = NULL; ns->uop_root = NULL; ns->default_access = ACCESS_UNKNOWN; ns->parent = parent; for (in = GFC_INTRINSIC_BEGIN; in != GFC_INTRINSIC_END; in++) ns->operator_access[in] = ACCESS_UNKNOWN; /* Initialize default implicit types. */ for (i = 'a'; i <= 'z'; i++) { ns->set_flag[i - 'a'] = 0; ts = &ns->default_type[i - 'a']; if (ns->parent != NULL) { /* Copy parent settings */ *ts = ns->parent->default_type[i - 'a']; continue; } if (gfc_option.flag_implicit_none != 0) { gfc_clear_ts (ts); continue; } if ('i' <= i && i <= 'n') { ts->type = BT_INTEGER; ts->kind = gfc_default_integer_kind (); } else { ts->type = BT_REAL; ts->kind = gfc_default_real_kind (); } } return ns; } /* Comparison function for symtree nodes. */ static int compare_symtree (void * _st1, void * _st2) { gfc_symtree *st1, *st2; st1 = (gfc_symtree *) _st1; st2 = (gfc_symtree *) _st2; return strcmp (st1->name, st2->name); } /* Allocate a new symtree node and associate it with the new symbol. */ gfc_symtree * gfc_new_symtree (gfc_symtree ** root, const char *name) { gfc_symtree *st; st = gfc_getmem (sizeof (gfc_symtree)); strcpy (st->name, name); gfc_insert_bbt (root, st, compare_symtree); return st; } /* Delete a symbol from the tree. Does not free the symbol itself! */ static void delete_symtree (gfc_symtree ** root, const char *name) { gfc_symtree st, *st0; st0 = gfc_find_symtree (*root, name); strcpy (st.name, name); gfc_delete_bbt (root, &st, compare_symtree); gfc_free (st0); } /* Given a root symtree node and a name, try to find the symbol within the namespace. Returns NULL if the symbol is not found. */ gfc_symtree * gfc_find_symtree (gfc_symtree * st, const char *name) { int c; while (st != NULL) { c = strcmp (name, st->name); if (c == 0) return st; st = (c < 0) ? st->left : st->right; } return NULL; } /* Given a name find a user operator node, creating it if it doesn't exist. These are much simpler than symbols because they can't be ambiguous with one another. */ gfc_user_op * gfc_get_uop (const char *name) { gfc_user_op *uop; gfc_symtree *st; st = gfc_find_symtree (gfc_current_ns->uop_root, name); if (st != NULL) return st->n.uop; st = gfc_new_symtree (&gfc_current_ns->uop_root, name); uop = st->n.uop = gfc_getmem (sizeof (gfc_user_op)); strcpy (uop->name, name); uop->access = ACCESS_UNKNOWN; uop->ns = gfc_current_ns; return uop; } /* Given a name find the user operator node. Returns NULL if it does not exist. */ gfc_user_op * gfc_find_uop (const char *name, gfc_namespace * ns) { gfc_symtree *st; if (ns == NULL) ns = gfc_current_ns; st = gfc_find_symtree (ns->uop_root, name); return (st == NULL) ? NULL : st->n.uop; } /* Remove a gfc_symbol structure and everything it points to. */ void gfc_free_symbol (gfc_symbol * sym) { if (sym == NULL) return; gfc_free_array_spec (sym->as); free_components (sym->components); gfc_free_expr (sym->value); gfc_free_namelist (sym->namelist); gfc_free_namespace (sym->formal_ns); gfc_free_interface (sym->generic); gfc_free_formal_arglist (sym->formal); gfc_free (sym); } /* Allocate and initialize a new symbol node. */ gfc_symbol * gfc_new_symbol (const char *name, gfc_namespace * ns) { gfc_symbol *p; p = gfc_getmem (sizeof (gfc_symbol)); gfc_clear_ts (&p->ts); gfc_clear_attr (&p->attr); p->ns = ns; p->declared_at = gfc_current_locus; if (strlen (name) > GFC_MAX_SYMBOL_LEN) gfc_internal_error ("new_symbol(): Symbol name too long"); strcpy (p->name, name); return p; } /* Generate an error if a symbol is ambiguous. */ static void ambiguous_symbol (const char *name, gfc_symtree * st) { if (st->n.sym->module[0]) gfc_error ("Name '%s' at %C is an ambiguous reference to '%s' " "from module '%s'", name, st->n.sym->name, st->n.sym->module); else gfc_error ("Name '%s' at %C is an ambiguous reference to '%s' " "from current program unit", name, st->n.sym->name); } /* Search for a symbol starting in the current namespace, resorting to any parent namespaces if requested by a nonzero parent_flag. Returns nonzero if the symbol is ambiguous. */ int gfc_find_sym_tree (const char *name, gfc_namespace * ns, int parent_flag, gfc_symtree ** result) { gfc_symtree *st; if (ns == NULL) ns = gfc_current_ns; do { st = gfc_find_symtree (ns->sym_root, name); if (st != NULL) { *result = st; if (st->ambiguous) { ambiguous_symbol (name, st); return 1; } return 0; } if (!parent_flag) break; ns = ns->parent; } while (ns != NULL); *result = NULL; return 0; } int gfc_find_symbol (const char *name, gfc_namespace * ns, int parent_flag, gfc_symbol ** result) { gfc_symtree *st; int i; i = gfc_find_sym_tree (name, ns, parent_flag, &st); if (st == NULL) *result = NULL; else *result = st->n.sym; return i; } /* Save symbol with the information necessary to back it out. */ static void save_symbol_data (gfc_symbol * sym) { if (sym->new || sym->old_symbol != NULL) return; sym->old_symbol = gfc_getmem (sizeof (gfc_symbol)); *(sym->old_symbol) = *sym; sym->tlink = changed_syms; changed_syms = sym; } /* Given a name, find a symbol, or create it if it does not exist yet in the current namespace. If the symbol is found we make sure that it's OK. The integer return code indicates 0 All OK 1 The symbol name was ambiguous 2 The name meant to be established was already host associated. So if the return value is nonzero, then an error was issued. */ int gfc_get_sym_tree (const char *name, gfc_namespace * ns, gfc_symtree ** result) { gfc_symtree *st; gfc_symbol *p; /* This doesn't usually happen during resolution. */ if (ns == NULL) ns = gfc_current_ns; /* Try to find the symbol in ns. */ st = gfc_find_symtree (ns->sym_root, name); if (st == NULL) { /* If not there, create a new symbol. */ p = gfc_new_symbol (name, ns); /* Add to the list of tentative symbols. */ p->old_symbol = NULL; p->tlink = changed_syms; p->mark = 1; p->new = 1; changed_syms = p; st = gfc_new_symtree (&ns->sym_root, name); st->n.sym = p; p->refs++; } else { /* Make sure the existing symbol is OK. */ if (st->ambiguous) { ambiguous_symbol (name, st); return 1; } p = st->n.sym; if (p->ns != ns && (!p->attr.function || ns->proc_name != p)) { /* Symbol is from another namespace. */ gfc_error ("Symbol '%s' at %C has already been host associated", name); return 2; } p->mark = 1; /* Copy in case this symbol is changed. */ save_symbol_data (p); } *result = st; return 0; } int gfc_get_symbol (const char *name, gfc_namespace * ns, gfc_symbol ** result) { gfc_symtree *st; int i; i = gfc_get_sym_tree (name, ns, &st); if (i != 0) return i; if (st) *result = st->n.sym; else *result = NULL; return i; } /* Subroutine that searches for a symbol, creating it if it doesn't exist, but tries to host-associate the symbol if possible. */ int gfc_get_ha_sym_tree (const char *name, gfc_symtree ** result) { gfc_symtree *st; int i; i = gfc_find_sym_tree (name, gfc_current_ns, 0, &st); if (st != NULL) { save_symbol_data (st->n.sym); *result = st; return i; } if (gfc_current_ns->parent != NULL) { i = gfc_find_sym_tree (name, gfc_current_ns->parent, 1, &st); if (i) return i; if (st != NULL) { *result = st; return 0; } } return gfc_get_sym_tree (name, gfc_current_ns, result); } int gfc_get_ha_symbol (const char *name, gfc_symbol ** result) { int i; gfc_symtree *st; i = gfc_get_ha_sym_tree (name, &st); if (st) *result = st->n.sym; else *result = NULL; return i; } /* Return true if both symbols could refer to the same data object. Does not take account of aliasing due to equivalence statements. */ int gfc_symbols_could_alias (gfc_symbol * lsym, gfc_symbol * rsym) { /* Aliasing isn't possible if the symbols have different base types. */ if (gfc_compare_types (&lsym->ts, &rsym->ts) == 0) return 0; /* Pointers can point to other pointers, target objects and allocatable objects. Two allocatable objects cannot share the same storage. */ if (lsym->attr.pointer && (rsym->attr.pointer || rsym->attr.allocatable || rsym->attr.target)) return 1; if (lsym->attr.target && rsym->attr.pointer) return 1; if (lsym->attr.allocatable && rsym->attr.pointer) return 1; return 0; } /* Undoes all the changes made to symbols in the current statement. This subroutine is made simpler due to the fact that attributes are never removed once added. */ void gfc_undo_symbols (void) { gfc_symbol *p, *q, *old; for (p = changed_syms; p; p = q) { q = p->tlink; if (p->new) { /* Symbol was new. */ delete_symtree (&p->ns->sym_root, p->name); p->refs--; if (p->refs < 0) gfc_internal_error ("gfc_undo_symbols(): Negative refs"); if (p->refs == 0) gfc_free_symbol (p); continue; } /* Restore previous state of symbol. Just copy simple stuff. */ p->mark = 0; old = p->old_symbol; p->ts.type = old->ts.type; p->ts.kind = old->ts.kind; p->attr = old->attr; if (p->value != old->value) { gfc_free_expr (old->value); p->value = NULL; } if (p->as != old->as) { if (p->as) gfc_free_array_spec (p->as); p->as = old->as; } p->generic = old->generic; p->component_access = old->component_access; if (p->namelist != NULL && old->namelist == NULL) { gfc_free_namelist (p->namelist); p->namelist = NULL; } else { if (p->namelist_tail != old->namelist_tail) { gfc_free_namelist (old->namelist_tail); old->namelist_tail->next = NULL; } } p->namelist_tail = old->namelist_tail; if (p->formal != old->formal) { gfc_free_formal_arglist (p->formal); p->formal = old->formal; } gfc_free (p->old_symbol); p->old_symbol = NULL; p->tlink = NULL; } changed_syms = NULL; } /* Makes the changes made in the current statement permanent-- gets rid of undo information. */ void gfc_commit_symbols (void) { gfc_symbol *p, *q; for (p = changed_syms; p; p = q) { q = p->tlink; p->tlink = NULL; p->mark = 0; p->new = 0; if (p->old_symbol != NULL) { gfc_free (p->old_symbol); p->old_symbol = NULL; } } changed_syms = NULL; } /* Recursive function that deletes an entire tree and all the user operator nodes that it contains. */ static void free_uop_tree (gfc_symtree * uop_tree) { if (uop_tree == NULL) return; free_uop_tree (uop_tree->left); free_uop_tree (uop_tree->right); gfc_free_interface (uop_tree->n.uop->operator); gfc_free (uop_tree->n.uop); gfc_free (uop_tree); } /* Recursive function that deletes an entire tree and all the symbols that it contains. */ static void free_sym_tree (gfc_symtree * sym_tree) { gfc_namespace *ns; gfc_symbol *sym; if (sym_tree == NULL) return; free_sym_tree (sym_tree->left); free_sym_tree (sym_tree->right); sym = sym_tree->n.sym; sym->refs--; if (sym->refs < 0) gfc_internal_error ("free_sym_tree(): Negative refs"); if (sym->formal_ns != NULL && sym->refs == 1) { /* As formal_ns contains a reference to sym, delete formal_ns just before the deletion of sym. */ ns = sym->formal_ns; sym->formal_ns = NULL; gfc_free_namespace (ns); } else if (sym->refs == 0) { /* Go ahead and delete the symbol. */ gfc_free_symbol (sym); } gfc_free (sym_tree); } /* Free a namespace structure and everything below it. Interface lists associated with intrinsic operators are not freed. These are taken care of when a specific name is freed. */ void gfc_free_namespace (gfc_namespace * ns) { gfc_charlen *cl, *cl2; gfc_namespace *p, *q; gfc_intrinsic_op i; if (ns == NULL) return; gfc_free_statements (ns->code); free_sym_tree (ns->sym_root); free_uop_tree (ns->uop_root); for (cl = ns->cl_list; cl; cl = cl2) { cl2 = cl->next; gfc_free_expr (cl->length); gfc_free (cl); } free_st_labels (ns->st_labels); gfc_free_equiv (ns->equiv); for (i = GFC_INTRINSIC_BEGIN; i != GFC_INTRINSIC_END; i++) gfc_free_interface (ns->operator[i]); gfc_free_data (ns->data); p = ns->contained; gfc_free (ns); /* Recursively free any contained namespaces. */ while (p != NULL) { q = p; p = p->sibling; gfc_free_namespace (q); } } void gfc_symbol_init_2 (void) { gfc_current_ns = gfc_get_namespace (NULL); } void gfc_symbol_done_2 (void) { gfc_free_namespace (gfc_current_ns); gfc_current_ns = NULL; } /* Clear mark bits from symbol nodes associated with a symtree node. */ static void clear_sym_mark (gfc_symtree * st) { st->n.sym->mark = 0; } /* Recursively traverse the symtree nodes. */ void gfc_traverse_symtree (gfc_symtree * st, void (*func) (gfc_symtree *)) { if (st != NULL) { (*func) (st); gfc_traverse_symtree (st->left, func); gfc_traverse_symtree (st->right, func); } } /* Recursive namespace traversal function. */ static void traverse_ns (gfc_symtree * st, void (*func) (gfc_symbol *)) { if (st == NULL) return; if (st->n.sym->mark == 0) (*func) (st->n.sym); st->n.sym->mark = 1; traverse_ns (st->left, func); traverse_ns (st->right, func); } /* Call a given function for all symbols in the namespace. We take care that each gfc_symbol node is called exactly once. */ void gfc_traverse_ns (gfc_namespace * ns, void (*func) (gfc_symbol *)) { gfc_traverse_symtree (ns->sym_root, clear_sym_mark); traverse_ns (ns->sym_root, func); } /* Given a symbol, mark it as SAVEd if it is allowed. */ static void save_symbol (gfc_symbol * sym) { if (sym->attr.use_assoc) return; if (sym->attr.in_common || sym->attr.dummy || sym->attr.flavor != FL_VARIABLE) return; gfc_add_save (&sym->attr, &sym->declared_at); } /* Mark those symbols which can be SAVEd as such. */ void gfc_save_all (gfc_namespace * ns) { gfc_traverse_ns (ns, save_symbol); } #ifdef GFC_DEBUG /* Make sure that no changes to symbols are pending. */ void gfc_symbol_state(void) { if (changed_syms != NULL) gfc_internal_error("Symbol changes still pending!"); } #endif /************** Global symbol handling ************/ /* Search a tree for the global symbol. */ gfc_gsymbol * gfc_find_gsymbol (gfc_gsymbol *symbol, char *name) { gfc_gsymbol *s; if (symbol == NULL) return NULL; if (strcmp (symbol->name, name) == 0) return symbol; s = gfc_find_gsymbol (symbol->left, name); if (s != NULL) return s; s = gfc_find_gsymbol (symbol->right, name); if (s != NULL) return s; return NULL; } /* Compare two global symbols. Used for managing the BB tree. */ static int gsym_compare (void * _s1, void * _s2) { gfc_gsymbol *s1, *s2; s1 = (gfc_gsymbol *)_s1; s2 = (gfc_gsymbol *)_s2; return strcmp(s1->name, s2->name); } /* Get a global symbol, creating it if it doesn't exist. */ gfc_gsymbol * gfc_get_gsymbol (char *name) { gfc_gsymbol *s; s = gfc_find_gsymbol (gfc_gsym_root, name); if (s != NULL) return s; s = gfc_getmem (sizeof (gfc_gsymbol)); s->type = GSYM_UNKNOWN; strcpy (s->name, name); gfc_insert_bbt (&gfc_gsym_root, s, gsym_compare); return s; }