[C++ Patch] Handle separately and in grokfndecl error messages

[Paolo Carlini]

Hi,

I split out two - rather straightforward IMHO - changes from the largish 
patch I posted a few days ago: this one improves the accuracy of some 
error messages produced by grokfndecl.

Tested x86_64-linux.

Thanks,
Paolo.

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


/cp
2013-03-25  Paolo Carlini  <paolo.carl...@oracle.com>

        * decl.c (grokfndecl): Handle separately <inline> and <constexpr>
        error messages.

/testsuite
2013-03-25  Paolo Carlini  <paolo.carl...@oracle.com>

        * g++.dg/cpp0x/constexpr-friend-2.C: New.
        * g++.dg/cpp0x/constexpr-main.C: Likewise.
Index: cp/decl.c
===================================================================
--- cp/decl.c   (revision 197053)
+++ cp/decl.c   (working copy)
@@ -7426,13 +7426,16 @@ grokfndecl (tree ctype,
              return NULL_TREE;
            }
 
+         if (inlinep & 1)
+           error ("%<inline%> is not allowed in declaration of friend "
+                  "template specialization %qD",
+                  decl);
+         if (inlinep & 2)
+           error ("%<constexpr%> is not allowed in declaration of friend "
+                  "template specialization %qD",
+                  decl);
          if (inlinep)
-           {
-             error ("%<inline%> is not allowed in declaration of friend "
-                    "template specialization %qD",
-                    decl);
-             return NULL_TREE;
-           }
+           return NULL_TREE;
        }
     }
 
@@ -7471,8 +7474,10 @@ grokfndecl (tree ctype,
     {
       if (PROCESSING_REAL_TEMPLATE_DECL_P())
        error ("cannot declare %<::main%> to be a template");
-      if (inlinep)
+      if (inlinep & 1)
        error ("cannot declare %<::main%> to be inline");
+      if (inlinep & 2)
+       error ("cannot declare %<::main%> to be constexpr");
       if (!publicp)
        error ("cannot declare %<::main%> to be static");
       inlinep = 0;
Index: testsuite/g++.dg/cpp0x/constexpr-friend-2.C
===================================================================
--- testsuite/g++.dg/cpp0x/constexpr-friend-2.C (revision 0)
+++ testsuite/g++.dg/cpp0x/constexpr-friend-2.C (working copy)
@@ -0,0 +1,7 @@
+// { dg-do compile { target c++11 } }
+
+template<typename T> void f(T);
+
+template <class T> class A {
+  friend constexpr void f<>(int);  // { dg-error "'constexpr' is not allowed" }
+};
Index: testsuite/g++.dg/cpp0x/constexpr-main.C
===================================================================
--- testsuite/g++.dg/cpp0x/constexpr-main.C     (revision 0)
+++ testsuite/g++.dg/cpp0x/constexpr-main.C     (working copy)
@@ -0,0 +1,3 @@
+// { dg-do compile { target c++11 } }
+
+constexpr int main ();  // { dg-error "constexpr" }