Remove symbol_matches_domain. This fixes

PR c++/16253.

symbol_matches_domain was permitting searches for a VAR_DOMAIN
symbol to also match STRUCT_DOMAIN symbols for languages like C++
where STRUCT_DOMAIN symbols also define a typedef of the same name,
e.g., "struct foo {}" introduces a typedef of the name "foo".

Problems occur if there exists both a VAR_DOMAIN and STRUCT_DOMAIN
symbol of the same name. Then it is essentially a race between which
symbol is found first. The other symbol is obscurred.
[This is a relatively common idiom: enum e { ... } e;]

This patchset moves this "language defines a typedef" logic to
lookup_symbol[_in_language], looking first for a symbol in the given
domain and falling back to searching STRUCT_DOMAIN when/if appropriate.

2014-04-14  Keith Seitz  <keiths@redhat.com>

	PR c++/16253
	* ada-lang.c (ada_symbol_matches_domain): Moved here and renamed
	from symbol_matches_domain in symtab.c. All local callers
	of symbol_matches_domain updated.
	(standard_lookup): If DOMAIN is VAR_DOMAIN and no symbol is found,
	search STRUCT_DOMAIN.
	(ada_find_any_type_symbol): Do not search STRUCT_DOMAIN
	independently.  standard_lookup will do that automatically.
	* cp-namespace.c (cp_lookup_symbol_nonlocal): Explain when/why
	VAR_DOMAIN searches may return a STRUCT_DOMAIN match.
	(cp_lookup_symbol_in_namespace): Likewise.
	If no VAR_DOMAIN symbol is found, search STRUCT_DOMAIN.
	(cp_lookup_symbol_exports): Explain when/why VAR_DOMAIN searches
	may return a STRUCT_DOMAIN match.
	(lookup_symbol_file): Search for the class name in STRUCT_DOMAIN.
	* cp-support.c: Include language.h.
	(inspect_type): Explicitly search STRUCT_DOMAIN before searching
	VAR_DOMAIN.
	* psymtab.c (match_partial_symbol): Compare the requested
	domain with the symbol's domain directly.
	(lookup_partial_symbol): Likewise.
	* symtab.c (lookup_symbol_in_language): Explain when/why
	VAR_DOMAIN searches may return a STRUCT_DOMAIN match.
	If no VAR_DOMAIN symbol is found, search STRUCT_DOMAIN for
	appropriate languages.
	(symbol_matches_domain): Renamed `ada_symbol_matches_domain'
	and moved to ada-lang.c
	(lookup_block_symbol): Explain that this function only returns
	symbol matching the requested DOMAIN.
	Compare the requested domain with the symbol's domain directly.
	(iterate_over_symbols): Compare the requested domain with the
	symbol's domain directly.
	* symtab.h (symbol_matches_domain): Remove.

2014-04-14  Keith Seitz  <keiths@redhat.com>

	PR c++/16253
	* gdb.cp/var-tag.cc: New file.
	* gdb.cp/var-tag.exp: New file.
	* gdb.dwarf2/dw2-ada-ffffffff.exp: Set the language to C++.
	* gdb.dwarf2/dw2-anon-mptr.exp: Likewise.
	* gdb.dwarf2/dw2-double-set-die-type.exp: Likewise.
	* gdb.dwarf2/dw2-inheritance.exp: Likewise.

1 files changed, 31 insertions, 29 deletions

diff --git a/gdb/symtab.c b/gdb/symtab.c
index 66d1624..15ac3d1 100644
--- a/gdb/symtab.c
+++ b/gdb/symtab.c
@@ -1310,7 +1310,11 @@ demangle_for_lookup (const char *name, enum language lang,
    NAME is a field of the current implied argument `this'.  If so set
    *IS_A_FIELD_OF_THIS to 1, otherwise set it to zero.
    BLOCK_FOUND is set to the block in which NAME is found (in the case of
-   a field of `this', value_of_this sets BLOCK_FOUND to the proper value.)  */
+   a field of `this', value_of_this sets BLOCK_FOUND to the proper value.)
+
+   If DOMAIN is VAR_DOMAIN and the language permits using tag names for
+   elaborated types, such as classes in C++, this function will search
+   STRUCT_DOMAIN if no matching is found.  */
 
 /* This function (or rather its subordinates) have a bunch of loops and
    it would seem to be attractive to put in some QUIT's (though I'm not really
@@ -1333,6 +1337,23 @@ lookup_symbol_in_language (const char *name, const struct block *block,
 
   returnval = lookup_symbol_aux (modified_name, block, domain, lang,
 				 is_a_field_of_this);
+  if (returnval == NULL)
+    {
+      if (is_a_field_of_this != NULL
+	  && is_a_field_of_this->type != NULL)
+	return NULL;
+
+      /* Some languages define typedefs of a type equal to its tag name,
+	 e.g., in C++, "struct foo { ... }" also defines a typedef for
+	 "foo".  */
+      if (domain == VAR_DOMAIN
+	  && (lang == language_cplus || lang == language_java
+	      || lang == language_ada || lang == language_d))
+	{
+	  returnval = lookup_symbol_aux (modified_name, block, STRUCT_DOMAIN,
+					 lang, is_a_field_of_this);
+	}
+    }
   do_cleanups (cleanup);
 
   return returnval;
@@ -1907,27 +1928,6 @@ lookup_symbol_global (const char *name,
   return lookup_data.result;
 }
 
-int
-symbol_matches_domain (enum language symbol_language,
-		       domain_enum symbol_domain,
-		       domain_enum domain)
-{
-  /* For C++ "struct foo { ... }" also defines a typedef for "foo".
-     A Java class declaration also defines a typedef for the class.
-     Similarly, any Ada type declaration implicitly defines a typedef.  */
-  if (symbol_language == language_cplus
-      || symbol_language == language_d
-      || symbol_language == language_java
-      || symbol_language == language_ada)
-    {
-      if ((domain == VAR_DOMAIN || domain == STRUCT_DOMAIN)
-	  && symbol_domain == STRUCT_DOMAIN)
-	return 1;
-    }
-  /* For all other languages, strict match is required.  */
-  return (symbol_domain == domain);
-}
-
 /* Look up a type named NAME in the struct_domain.  The type returned
    must not be opaque -- i.e., must have at least one field
    defined.  */
@@ -2050,7 +2050,12 @@ basic_lookup_transparent_type (const char *name)
    binary search terminates, we drop through and do a straight linear
    search on the symbols.  Each symbol which is marked as being a ObjC/C++
    symbol (language_cplus or language_objc set) has both the encoded and
-   non-encoded names tested for a match.  */
+   non-encoded names tested for a match.
+
+   This function specifically disallows domain mismatches.  If a language
+   defines a typedef for an elaborated type, such as classes in C++,
+   then this function will need to be called twice, once to search
+   VAR_DOMAIN and once to search STRUCT_DOMAIN.  */
 
 struct symbol *
 lookup_block_symbol (const struct block *block, const char *name,
@@ -2065,8 +2070,7 @@ lookup_block_symbol (const struct block *block, const char *name,
 	   sym != NULL;
 	   sym = block_iter_name_next (name, &iter))
 	{
-	  if (symbol_matches_domain (SYMBOL_LANGUAGE (sym),
-				     SYMBOL_DOMAIN (sym), domain))
+	  if (SYMBOL_DOMAIN (sym) == domain)
 	    return sym;
 	}
       return NULL;
@@ -2085,8 +2089,7 @@ lookup_block_symbol (const struct block *block, const char *name,
 	   sym != NULL;
 	   sym = block_iter_name_next (name, &iter))
 	{
-	  if (symbol_matches_domain (SYMBOL_LANGUAGE (sym),
-				     SYMBOL_DOMAIN (sym), domain))
+	  if (SYMBOL_DOMAIN (sym) == domain)
 	    {
 	      sym_found = sym;
 	      if (!SYMBOL_IS_ARGUMENT (sym))
@@ -2120,8 +2123,7 @@ iterate_over_symbols (const struct block *block, const char *name,
        sym != NULL;
        sym = block_iter_name_next (name, &iter))
     {
-      if (symbol_matches_domain (SYMBOL_LANGUAGE (sym),
-				 SYMBOL_DOMAIN (sym), domain))
+      if (SYMBOL_DOMAIN (sym) == domain)
 	{
 	  if (!callback (sym, data))
 	    return;