Re: [rfa] namespace scope, take 2

[David Carlton <carlton@math.stanford.edu>]

On Mon, 19 May 2003 10:45:08 -0400, Daniel Jacobowitz <drow@mvista.com> said:

> Just a couple small comments.  Most of it looks good.

Thanks, checked in with your and Elena's changes.  Revised
cp-namespace.c below.

David Carlton
carlton@math.stanford.edu

Index: cp-namespace.c
===================================================================
RCS file: /cvs/src/src/gdb/cp-namespace.c,v
retrieving revision 1.1
diff -u -p -r1.1 cp-namespace.c
--- cp-namespace.c	15 Apr 2003 23:07:11 -0000	1.1
+++ cp-namespace.c	20 May 2003 03:55:44 -0000
@@ -1,7 +1,7 @@
 /* Helper routines for C++ support in GDB.
    Copyright 2003 Free Software Foundation, Inc.
 
-   Contributed by David Carlton.
+   Contributed by David Carlton and by Kealia, Inc.
 
    This file is part of GDB.
 
@@ -52,6 +52,21 @@ static struct using_direct *cp_add_using
 static struct using_direct *cp_copy_usings (struct using_direct *using,
 					    struct obstack *obstack);
 
+static struct symbol *lookup_namespace_scope (const char *name,
+					      const char *linkage_name,
+					      const struct block *block,
+					      const domain_enum domain,
+					      struct symtab **symtab,
+					      const char *scope,
+					      int scope_len);
+
+static struct symbol *lookup_symbol_file (const char *name,
+					  const char *linkage_name,
+					  const struct block *block,
+					  const domain_enum domain,
+					  struct symtab **symtab,
+					  int anonymous_namespace);
+
 /* Set up support for dealing with C++ namespace info in the current
    symtab.  */
 
@@ -262,5 +277,179 @@ cp_copy_usings (struct using_direct *usi
       xfree (using);
 
       return retval;
+    }
+}
+
+/* The C++-specific version of name lookup for static and global
+   names.  This makes sure that names get looked for in all namespaces
+   that are in scope.  NAME is the natural name of the symbol that
+   we're looking for, LINKAGE_NAME (which is optional) is its linkage
+   name, BLOCK is the block that we're searching within, DOMAIN says
+   what kind of symbols we're looking for, and if SYMTAB is non-NULL,
+   we should store the symtab where we found the symbol in it.  */
+
+struct symbol *
+cp_lookup_symbol_nonlocal (const char *name,
+			   const char *linkage_name,
+			   const struct block *block,
+			   const domain_enum domain,
+			   struct symtab **symtab)
+{
+  return lookup_namespace_scope (name, linkage_name, block, domain,
+				 symtab, block_scope (block), 0);
+}
+
+/* Lookup NAME at namespace scope (or, in C terms, in static and
+   global variables).  SCOPE is the namespace that the current
+   function is defined within; only consider namespaces whose length
+   is at least SCOPE_LEN.  Other arguments are as in
+   cp_lookup_symbol_nonlocal.
+
+   For example, if we're within a function A::B::f and looking for a
+   symbol f, this will get called with NAME = "f", SCOPE = "A::B", and
+   SCOPE_LEN = 0.  It then calls itself with NAME and SCOPE the same,
+   but with SCOPE_LEN = 1.  And then it calls itself with NAME and
+   SCOPE the same, but with SCOPE_LEN = 4.  This third call looks for
+   "A::B::x"; if it doesn't find it, then the second call looks for
+   "A::x", and if that call fails, then the first call looks for
+   "x".  */
+
+static struct symbol *
+lookup_namespace_scope (const char *name,
+			const char *linkage_name,
+			const struct block *block,
+			const domain_enum domain,
+			struct symtab **symtab,
+			const char *scope,
+			int scope_len)
+{
+  char *namespace;
+
+  if (scope[scope_len] != '\0')
+    {
+      /* Recursively search for names in child namespaces first.  */
+
+      struct symbol *sym;
+      int new_scope_len = scope_len;
+
+      /* If the current scope is followed by "::", skip past that.  */
+      if (new_scope_len != 0)
+	{
+	  gdb_assert (scope[new_scope_len] == ':');
+	  new_scope_len += 2;
+	}
+      new_scope_len += cp_find_first_component (scope + new_scope_len);
+      sym = lookup_namespace_scope (name, linkage_name, block,
+				    domain, symtab,
+				    scope, new_scope_len);
+      if (sym != NULL)
+	return sym;
+    }
+
+  /* Okay, we didn't find a match in our children, so look for the
+     name in the current namespace.  */
+
+  namespace = alloca (scope_len + 1);
+  strncpy (namespace, scope, scope_len);
+  namespace[scope_len] = '\0';
+  return cp_lookup_symbol_namespace (namespace, name, linkage_name,
+				     block, domain, symtab);
+}
+
+/* Look up NAME in the C++ namespace NAMESPACE, applying the using
+   directives that are active in BLOCK.  Other arguments are as in
+   cp_lookup_symbol_nonlocal.  */
+
+struct symbol *
+cp_lookup_symbol_namespace (const char *namespace,
+			    const char *name,
+			    const char *linkage_name,
+			    const struct block *block,
+			    const domain_enum domain,
+			    struct symtab **symtab)
+{
+  const struct using_direct *current;
+  struct symbol *sym;
+
+  /* First, go through the using directives.  If any of them add new
+     names to the namespace we're searching in, see if we can find a
+     match by applying them.  */
+
+  for (current = block_using (block);
+       current != NULL;
+       current = current->next)
+    {
+      if (strcmp (namespace, current->outer) == 0)
+	{
+	  sym = cp_lookup_symbol_namespace (current->inner,
+					    name,
+					    linkage_name,
+					    block,
+					    domain,
+					    symtab);
+	  if (sym != NULL)
+	    return sym;
+	}
+    }
+
+  /* We didn't find anything by applying any of the using directives
+     that are still applicable; so let's see if we've got a match
+     using the current namespace.  */
+  
+  if (namespace[0] == '\0')
+    {
+      return lookup_symbol_file (name, linkage_name, block,
+				 domain, symtab, 0);
+    }
+  else
+    {
+      char *concatenated_name
+	= alloca (strlen (namespace) + 2 + strlen (name) + 1);
+      strcpy (concatenated_name, namespace);
+      strcat (concatenated_name, "::");
+      strcat (concatenated_name, name);
+      sym = lookup_symbol_file (concatenated_name, linkage_name,
+				block, domain, symtab,
+				cp_is_anonymous (namespace));
+      return sym;
+    }
+}
+
+/* Look up NAME in BLOCK's static block and in global blocks.  If
+   ANONYMOUS_NAMESPACE is nonzero, the symbol in question is located
+   within an anonymous namespace.  Other arguments are as in
+   cp_lookup_symbol_nonlocal.  */
+
+static struct symbol *
+lookup_symbol_file (const char *name,
+		    const char *linkage_name,
+		    const struct block *block,
+		    const domain_enum domain,
+		    struct symtab **symtab,
+		    int anonymous_namespace)
+{
+  struct symbol *sym = NULL;
+
+  sym = lookup_symbol_static (name, linkage_name, block, domain, symtab);
+  if (sym != NULL)
+    return sym;
+
+  if (anonymous_namespace)
+    {
+      /* Symbols defined in anonymous namespaces have external linkage
+	 but should be treated as local to a single file nonetheless.
+	 So we only search the current file's global block.  */
+
+      const struct block *global_block = block_global_block (block);
+      
+      if (global_block != NULL)
+	return lookup_symbol_aux_block (name, linkage_name, global_block,
+					domain, symtab);
+      else
+	return NULL;
+    }
+  else
+    {
+      return lookup_symbol_global (name, linkage_name, domain, symtab);
     }
 }