[C++ Patch] Fix three additional locations

[Paolo Carlini]

Hi,

a few additional easy to fix cases where we thought that a plain error 
was good enough. Tested x86_64-linux.

Thanks, Paolo.

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

/cp
2019-01-08  Paolo Carlini  <paolo.carl...@oracle.com>

        * decl.c (grok_reference_init): Improve error location.
        (grokdeclarator): Likewise, improve two locations.

/testsuite
2019-01-08  Paolo Carlini  <paolo.carl...@oracle.com>

        * g++.dg/diagnostic/constexpr2.C: New.
        * g++.dg/diagnostic/ref3.C: Likewise.
Index: cp/decl.c
===================================================================
--- cp/decl.c   (revision 267675)
+++ cp/decl.c   (working copy)
@@ -5357,7 +5357,8 @@ grok_reference_init (tree decl, tree type, tree in
       if ((DECL_LANG_SPECIFIC (decl) == 0
           || DECL_IN_AGGR_P (decl) == 0)
          && ! DECL_THIS_EXTERN (decl))
-       error ("%qD declared as reference but not initialized", decl);
+       error_at (DECL_SOURCE_LOCATION (decl),
+                 "%qD declared as reference but not initialized", decl);
       return NULL_TREE;
     }
 
@@ -12517,8 +12518,9 @@ grokdeclarator (const cp_declarator *declarator,
                            unqualified_id);
                else if (constexpr_p && !initialized)
                  {
-                   error ("%<constexpr%> static data member %qD must have an "
-                          "initializer", decl);
+                   error_at (DECL_SOURCE_LOCATION (decl),
+                             "%<constexpr%> static data member %qD must "
+                             "have an initializer", decl);
                    constexpr_p = false;
                  }
 
@@ -12756,8 +12758,9 @@ grokdeclarator (const cp_declarator *declarator,
          }
        else if (constexpr_p && DECL_EXTERNAL (decl))
          {
-           error ("declaration of %<constexpr%> variable %qD "
-                  "is not a definition", decl);
+           error_at (DECL_SOURCE_LOCATION (decl),
+                     "declaration of %<constexpr%> variable %qD "
+                     "is not a definition", decl);
            constexpr_p = false;
          }
 
Index: testsuite/g++.dg/diagnostic/constexpr2.C
===================================================================
--- testsuite/g++.dg/diagnostic/constexpr2.C    (nonexistent)
+++ testsuite/g++.dg/diagnostic/constexpr2.C    (working copy)
@@ -0,0 +1,8 @@
+// { dg-do compile { target c++11 } }
+
+extern constexpr int i __attribute__((unused));  // { dg-error "22:declaration 
of .constexpr. variable .i." }
+
+struct S
+{
+  constexpr static int i __attribute__((unused));  // { dg-error 
"24:.constexpr. static data member .i." }
+};
Index: testsuite/g++.dg/diagnostic/ref3.C
===================================================================
--- testsuite/g++.dg/diagnostic/ref3.C  (nonexistent)
+++ testsuite/g++.dg/diagnostic/ref3.C  (working copy)
@@ -0,0 +1 @@
+int& i __attribute__((unused));  // { dg-error "6:.i. declared as reference" }