gcc/cp/name-lookup.c

   1 /* Definitions for C++ name lookup routines.
   2    Copyright (C) 2003 Free Software Foundation, Inc.
   3    Contributed by Gabriel Dos Reis <gdr@integrable-solutions.net>
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2, or (at your option)
  10 any later version.
  11
  12 GCC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  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
  19 the Free Software Foundation, 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, USA.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "tm.h"
  26 #include "tree.h"
  27 #include "cp-tree.h"
  28 #include "name-lookup.h"
  29 #include "timevar.h"
  30
  31 /* A free list of "cxx_binding"s, connected by their PREVIOUS.  */
  32 static GTY((deletable (""))) cxx_binding *free_bindings;
  33
  34 /* (GC)-allocate a binding object with VALUE and TYPE member initialized.  */
  35 cxx_binding *
  36 cxx_binding_make (tree value, tree type)
  37 {
  38   cxx_binding *binding;
  39   if (free_bindings)
  40     {
  41       binding = free_bindings;
  42       free_bindings = binding->previous;
  43     }
  44   else
  45     binding = ggc_alloc (sizeof (cxx_binding));
  46
  47   binding->value = value;
  48   binding->type = type;
  49
  50   return binding;
  51 }
  52
  53 /* Put BINDING back on the free list.  */
  54 void
  55 cxx_binding_free (cxx_binding *binding)
  56 {
  57   binding->previous = free_bindings;
  58   free_bindings = binding;
  59 }
  60 \f
  61 /* Return (from the stack of) the BINDING, if any, establihsed at SCOPE.  */
  62
  63 static inline cxx_binding *
  64 find_binding (cxx_scope *scope, cxx_binding *binding)
  65 {
  66   timevar_push (TV_NAME_LOOKUP);
  67
  68   for (; binding != NULL; binding = binding->previous)
  69     if (BINDING_SCOPE (binding) == scope)
  70       POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, binding);
  71
  72   POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, NULL);
  73 }
  74
  75 /* Return the binding for NAME in SCOPE, if any.  Otherwise, return NULL.  */
  76 cxx_binding *
  77 cxx_scope_find_binding_for_name (cxx_scope *scope, tree name)
  78 {
  79   cxx_binding *b = IDENTIFIER_NAMESPACE_BINDINGS (name);
  80   if (b)
  81     {
  82       /* Fold-in case where NAME is used only once.  */
  83       if (scope == BINDING_SCOPE (b) && b->previous == NULL)
  84         return b;
  85       return find_binding (scope, b);
  86     }
  87   return NULL;
  88 }
  89
  90 /* Always returns a binding for name in scope.  If no binding is
  91    found, make a new one.  */
  92
  93 cxx_binding *
  94 binding_for_name (cxx_scope *scope, tree name)
  95 {
  96   cxx_binding *result;
  97
  98   result = cxx_scope_find_binding_for_name (scope, name);
  99   if (result)
 100     return result;
 101   /* Not found, make a new one.  */
 102   result = cxx_binding_make (NULL, NULL);
 103   result->previous = IDENTIFIER_NAMESPACE_BINDINGS (name);
 104   BINDING_SCOPE (result) = scope;
 105   result->is_local = false;
 106   result->value_is_inherited = false;
 107   IDENTIFIER_NAMESPACE_BINDINGS (name) = result;
 108   return result;
 109 }
 110 \f
 111 /* Namespace-scope manipulation routines.  */
 112
 113 /* Return the binding value for name in scope.  */
 114
 115 tree
 116 namespace_binding (tree name, tree scope)
 117 {
 118   cxx_binding *binding;
 119
 120   if (scope == NULL)
 121     scope = global_namespace;
 122   scope = ORIGINAL_NAMESPACE (scope);
 123   binding = cxx_scope_find_binding_for_name (NAMESPACE_LEVEL (scope), name);
 124
 125   return binding ? binding->value : NULL_TREE;
 126 }
 127
 128 /* Set the binding value for name in scope.  */
 129
 130 void
 131 set_namespace_binding (tree name, tree scope, tree val)
 132 {
 133   cxx_binding *b;
 134
 135   timevar_push (TV_NAME_LOOKUP);
 136   if (scope == NULL_TREE)
 137     scope = global_namespace;
 138   b = binding_for_name (NAMESPACE_LEVEL (scope), name);
 139   BINDING_VALUE (b) = val;
 140   timevar_pop (TV_NAME_LOOKUP);
 141 }
 142