Hi,
we have these long standing issues with code like (c++/60385):
float foo4();
namespace foo4
{
// ....
}
where the name of the namespace conflicts with an existing declaration.
Error recovery is currently suboptimal, for example, c++/60385 is about
struct bar6
{
friend wchar_t bar1();
};
inside the namespace: due to the code in do_friend:
push_nested_namespace (ns);
decl = pushdecl_namespace_level (decl, /*is_friend=*/true);
pop_nested_namespace (ns);
we issue duplicate diagnostic about the wrong name and later we crash in
pop_namespace (the second time in push_namespace,
IDENTIFIER_NAMESPACE_VALUE isn't found set for the malformed namespace,
thus need_new is true, pushdecl is called...)
Now, I'm wondering how far we want to go with error recovery for such
snippets. Certainly, in analogy with the code at the beginning of
cp_parser_class_specifier_1, we can completely skip the body of such
malformed namespaces. That would be the first attached patchlet. Or we
can go on in cp_parser_namespace_definition but remember that
push_namespace didn't really succeed and keep things consistent, thus
avoid crashing in pop_namespace later, as currently happens. That would
be second patchlet. Both ideas pass testing and work for c++/68723 too
(as expected, the first patchlet leads to particularly neat diagnostic
for the very broken snippet in c++/68723, only the error about the wrong
namespace name, as for c++/60385).
Thanks!
Paolo.
//////////////////////
Index: name-lookup.c
===================================================================
--- name-lookup.c (revision 236809)
+++ name-lookup.c (working copy)
@@ -3685,7 +3685,7 @@ handle_namespace_attrs (tree ns, tree attributes)
/* Push into the scope of the NAME namespace. If NAME is NULL_TREE, then we
select a name that is unique to this compilation unit. */
-void
+bool
push_namespace (tree name)
{
tree d = NULL_TREE;
@@ -3759,7 +3759,11 @@ push_namespace (tree name)
TREE_PUBLIC (d) = 0;
else
TREE_PUBLIC (d) = 1;
- pushdecl (d);
+ if (pushdecl (d) == error_mark_node)
+ {
+ timevar_cond_stop (TV_NAME_LOOKUP, subtime);
+ return false;
+ }
if (anon)
{
/* Clear DECL_NAME for the benefit of debugging back ends. */
@@ -3777,6 +3781,7 @@ push_namespace (tree name)
current_namespace = d;
timevar_cond_stop (TV_NAME_LOOKUP, subtime);
+ return true;
}
/* Pop from the scope of the current namespace. */
Index: name-lookup.h
===================================================================
--- name-lookup.h (revision 236809)
+++ name-lookup.h (working copy)
@@ -312,7 +312,7 @@ extern tree push_inner_scope (tree);
extern void pop_inner_scope (tree, tree);
extern void push_binding_level (cp_binding_level *);
-extern void push_namespace (tree);
+extern bool push_namespace (tree);
extern void pop_namespace (void);
extern void push_nested_namespace (tree);
extern void pop_nested_namespace (tree);
Index: parser.c
===================================================================
--- parser.c (revision 236809)
+++ parser.c (working copy)
@@ -17549,7 +17549,11 @@ cp_parser_namespace_definition (cp_parser* parser)
}
/* Start the namespace. */
- push_namespace (identifier);
+ if (!push_namespace (identifier))
+ {
+ cp_parser_skip_to_end_of_block_or_statement (parser);
+ return;
+ }
/* Parse any nested namespace definition. */
if (cp_lexer_next_token_is (parser->lexer, CPP_SCOPE))
Index: name-lookup.c
===================================================================
--- name-lookup.c (revision 236799)
+++ name-lookup.c (working copy)
@@ -3685,7 +3685,7 @@ handle_namespace_attrs (tree ns, tree attributes)
/* Push into the scope of the NAME namespace. If NAME is NULL_TREE, then we
select a name that is unique to this compilation unit. */
-void
+bool
push_namespace (tree name)
{
tree d = NULL_TREE;
@@ -3759,7 +3759,11 @@ push_namespace (tree name)
TREE_PUBLIC (d) = 0;
else
TREE_PUBLIC (d) = 1;
- pushdecl (d);
+ if (pushdecl (d) == error_mark_node)
+ {
+ timevar_cond_stop (TV_NAME_LOOKUP, subtime);
+ return false;
+ }
if (anon)
{
/* Clear DECL_NAME for the benefit of debugging back ends. */
@@ -3777,6 +3781,7 @@ push_namespace (tree name)
current_namespace = d;
timevar_cond_stop (TV_NAME_LOOKUP, subtime);
+ return true;
}
/* Pop from the scope of the current namespace. */
Index: name-lookup.h
===================================================================
--- name-lookup.h (revision 236799)
+++ name-lookup.h (working copy)
@@ -312,7 +312,7 @@ extern tree push_inner_scope (tree);
extern void pop_inner_scope (tree, tree);
extern void push_binding_level (cp_binding_level *);
-extern void push_namespace (tree);
+extern bool push_namespace (tree);
extern void pop_namespace (void);
extern void push_nested_namespace (tree);
extern void pop_nested_namespace (tree);
Index: parser.c
===================================================================
--- parser.c (revision 236799)
+++ parser.c (working copy)
@@ -17549,7 +17549,7 @@ cp_parser_namespace_definition (cp_parser* parser)
}
/* Start the namespace. */
- push_namespace (identifier);
+ bool ok = push_namespace (identifier);
/* Parse any nested namespace definition. */
if (cp_lexer_next_token_is (parser->lexer, CPP_SCOPE))
@@ -17582,7 +17582,7 @@ cp_parser_namespace_definition (cp_parser* parser)
/* "inline namespace" is equivalent to a stub namespace definition
followed by a strong using directive. */
- if (is_inline)
+ if (is_inline && ok)
{
tree name_space = current_namespace;
/* Set up namespace association. */
@@ -17610,7 +17610,8 @@ cp_parser_namespace_definition (cp_parser* parser)
pop_namespace ();
/* Finish the namespace. */
- pop_namespace ();
+ if (ok)
+ pop_namespace ();
/* Look for the final `}'. */
cp_parser_require (parser, CPP_CLOSE_BRACE, RT_CLOSE_BRACE);
}
