[C++ Patch] PR 16603

[Paolo Carlini]

Hi,

in the audit trail of this *old* PR, which is about the miscompilation of:
char const c = 'q';

enum
  {
    x = c,
    y = sizeof(x)
  };

int test[y == sizeof(char) ? 1 : -1];

Andrew noticed that the problem is in the perform_integral_promotions 
call at the beginning of build_enumerator. Now, the "funny" thing is, I 
don't see why we should be calling it at all! Thus I applied the below 
and booted it all languages (minus Ada) on x86_64-linux multilib and 
tested C/C++ (the other languages in progress). Can you imagine a reason 
why it may not be Ok?

Thanks,
Paolo.

//////////////////////
/cp
2012-01-01  Paolo Carlini  <paolo.carl...@oracle.com>

        PR c++/16603
        * decl.c (build_enumerator): Don't call perform_integral_promotions
        on the value.

/testsuite
2012-01-01  Paolo Carlini  <paolo.carl...@oracle.com>

        PR c++/16603
        * g++.dg/parse/enum8.C: New.

Index: testsuite/g++.dg/parse/enum8.C
===================================================================
--- testsuite/g++.dg/parse/enum8.C      (revision 0)
+++ testsuite/g++.dg/parse/enum8.C      (revision 0)
@@ -0,0 +1,11 @@
+// PR c++/16603
+
+char const c = 'q';
+
+enum
+  {
+    x = c,
+    y = sizeof(x)
+  };
+
+int test[y == sizeof(char) ? 1 : -1];
Index: cp/decl.c
===================================================================
--- cp/decl.c   (revision 182769)
+++ cp/decl.c   (working copy)
@@ -12369,14 +12369,11 @@ build_enumerator (tree name, tree value, tree enum
        {
          value = cxx_constant_value (value);
 
-         if (TREE_CODE (value) == INTEGER_CST
-             && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (value)))
+         if (TREE_CODE (value) != INTEGER_CST
+             || ! INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (value)))
            {
-             value = perform_integral_promotions (value);
-           }
-         else
-           {
-             error ("enumerator value for %qD is not an integer constant", 
name);
+             error ("enumerator value for %qD is not an integer constant",
+                    name);
              value = NULL_TREE;
            }
        }