[C++ Patch] Check permerror return value

[Paolo Carlini]

Hi,

over the last weeks, while working on various diagnostic issues, I 
noticed a few defective permerror + inform pairs. Tested x86_64-linux.

Thanks, Paolo.

////////////////////

/cp
2018-07-16  Paolo Carlini  <paolo.carl...@oracle.com>

        * class.c (resolve_address_of_overloaded_function): Don't emit an
        inform if the matching permerror returns false.
        * pt.c (check_specialization_namespace): Likewise.

/testsuite
2018-07-16  Paolo Carlini  <paolo.carl...@oracle.com>

        * g++.dg/template/spec40.C: New.
        * g++.dg/parse/ptrmem8.C: Likewise.
Index: cp/class.c
===================================================================
--- cp/class.c  (revision 262687)
+++ cp/class.c  (working copy)
@@ -7919,10 +7919,11 @@ resolve_address_of_overloaded_function (tree targe
       if (!(complain & tf_error))
        return error_mark_node;
 
-      permerror (input_location, "assuming pointer to member %qD", fn);
-      if (!explained)
+      if (permerror (input_location, "assuming pointer to member %qD", fn)
+         && !explained)
        {
-         inform (input_location, "(a pointer to member can only be formed with 
%<&%E%>)", fn);
+         inform (input_location, "(a pointer to member can only be "
+                 "formed with %<&%E%>)", fn);
          explained = 1;
        }
     }
Index: cp/pt.c
===================================================================
--- cp/pt.c     (revision 262687)
+++ cp/pt.c     (working copy)
@@ -800,10 +800,10 @@ check_specialization_namespace (tree tmpl)
     return true;
   else
     {
-      permerror (input_location,
-                "specialization of %qD in different namespace", tmpl);
-      inform (DECL_SOURCE_LOCATION (tmpl),
-             "  from definition of %q#D", tmpl);
+      if (permerror (input_location,
+                    "specialization of %qD in different namespace", tmpl))
+       inform (DECL_SOURCE_LOCATION (tmpl),
+               "  from definition of %q#D", tmpl);
       return false;
     }
 }
Index: testsuite/g++.dg/template/spec40.C
===================================================================
--- testsuite/g++.dg/template/spec40.C  (nonexistent)
+++ testsuite/g++.dg/template/spec40.C  (working copy)
@@ -0,0 +1,12 @@
+// { dg-options "-fpermissive -w" }
+
+namespace N {
+  template <typename T>
+  struct S {
+    void f() {}  // { dg-bogus "from definition" }
+  };
+}
+
+namespace K {
+  template <> void N::S<char>::f() {}
+}
Index: testsuite/g++.dg/parse/ptrmem8.C
===================================================================
--- testsuite/g++.dg/parse/ptrmem8.C    (nonexistent)
+++ testsuite/g++.dg/parse/ptrmem8.C    (working copy)
@@ -0,0 +1,15 @@
+// { dg-options "-fpermissive -w" }
+
+struct A
+{
+  template<int> void foo()
+  {
+    void (A::* fp)();
+    fp = A::foo<0>;  // { dg-bogus "pointer to member" }
+  }
+};
+
+void bar()
+{
+  A().foo<0>();
+}