Patchwork PR c++/47957

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Submitter Dodji Seketeli
Date March 7, 2011, 9:12 p.m.
Message ID <m3fwqyljo2.fsf@redhat.com>
Download mbox | patch
Permalink /patch/85815/
State New
Headers show

Comments

Dodji Seketeli - March 7, 2011, 9:12 p.m.
Hello,

In the example of the patch below, the lookup of symbol 'T' yields the
template parameter instead of the typedef Base::T.  That's because
outer_binding considers the template-parameters-scope bindings from
Derived<T>::foo even though that template doesn't have it's own
template header.  outer_binding should first consider the class-scope
bindings from Derived<T>::foo.

The patch tightens binding_to_template_parms_of_scope_p to make it
only consider template parameters of the scope of a template which has
its own template header.

Tested on x86_64-unknown-linux-gnu against trunk.
Jason Merrill - March 8, 2011, 1:05 p.m.
OK.

Jason

Patch

diff --git a/gcc/cp/name-lookup.c b/gcc/cp/name-lookup.c
index 4117202..18e3441 100644
--- a/gcc/cp/name-lookup.c
+++ b/gcc/cp/name-lookup.c
@@ -4205,8 +4205,13 @@  qualified_lookup_using_namespace (tree name, tree scope,
 }
 
 /* Subroutine of outer_binding.
-   Returns TRUE if BINDING is a binding to a template parameter of SCOPE,
-   FALSE otherwise.  */
+
+   Returns TRUE if BINDING is a binding to a template parameter of
+   SCOPE.  In that case SCOPE is the scope of a primary template
+   parameter -- in the sense of G++, i.e, a template that has its own
+   template header.
+
+   Returns FALSE otherwise.  */
 
 static bool
 binding_to_template_parms_of_scope_p (cxx_binding *binding,
@@ -4222,6 +4227,8 @@  binding_to_template_parms_of_scope_p (cxx_binding *binding,
   return (scope
 	  && scope->this_entity
 	  && get_template_info (scope->this_entity)
+	  && PRIMARY_TEMPLATE_P (TI_TEMPLATE
+				 (get_template_info (scope->this_entity)))
 	  && parameter_of_template_p (binding_value,
 				      TI_TEMPLATE (get_template_info \
 						    (scope->this_entity))));
diff --git a/gcc/testsuite/g++.dg/lookup/template3.C b/gcc/testsuite/g++.dg/lookup/template3.C
new file mode 100644
index 0000000..e5f6f18
--- /dev/null
+++ b/gcc/testsuite/g++.dg/lookup/template3.C
@@ -0,0 +1,35 @@ 
+// Origin PR c++/47957
+// { dg-do compile }
+
+struct S
+{
+  int m;
+
+  S()
+    : m(0)
+  {
+  }
+};
+
+struct Base
+{
+  typedef S T;
+};
+
+template<class T>
+struct Derived : public Base
+{
+  int
+  foo()
+  {
+    T a; // This is Base::T, not the template parameter.
+    return a.m;
+  }
+};
+
+int
+main()
+{
+  Derived<char> d;
+  return d.foo();
+}