[patch][google] Backport r176665 to google/gcc-4_6 making narrowing conversions a pedwarn.

[Jeffrey Yasskin]

I'm backporting this so that, if we run into a particularly obnoxious
set of narrowing conversions in the C++11 transition, we can just
-Wno-narrowing instead of rolling a new gcc release.

Tested with check-c++ on ubuntu x86_64. Since this is going into a
google branch, I'll just commit it in a few hours unless I hear
complaints.

c-family/ChangeLog.google-4_6:
2011-11-02  Jeffrey Yasskin  <jyass...@google.com>

        Backport from rev 176665

        2011-07-22  Jason Merrill  <ja...@redhat.com>

                * c.opt (Wnarrowing): New.

cp/ChangeLog.google-4_6:
2011-11-02  Jeffrey Yasskin  <jyass...@google.com>

        Backport from rev 176665

        2011-07-22  Jason Merrill  <ja...@redhat.com>

                * typeck2.c (check_narrowing): Downgrade permerror to pedwarn.
                Make conditional on -Wnarrowing.

testsuite/ChangeLog.google-4_6:
2011-11-02  Jeffrey Yasskin  <jyass...@google.com>

        Backport from rev 176665

        2011-07-22  Jason Merrill  <ja...@redhat.com>

                * g++.dg/cpp0x/initlist55.C: New.

You can also review this at http://codereview.appspot.com/5330065/.

Property changes on: .
___________________________________________________________________
Modified: svn:mergeinfo
   Merged /trunk:r176665


Property changes on: libjava/classpath
___________________________________________________________________
Modified: svn:mergeinfo
   Merged /trunk/libjava/classpath:r176665

Index: gcc/c-family/c.opt
===================================================================
--- gcc/c-family/c.opt	(revision 180783)
+++ gcc/c-family/c.opt	(working copy)
@@ -493,6 +493,10 @@
 C ObjC C++ ObjC++ Warning
 Warn about use of multi-character character constants
 
+Wnarrowing
+C ObjC C++ ObjC++ Warning Var(warn_narrowing) Init(1)
+-Wno-narrowing	  In C++0x mode, ignore ill-formed narrowing conversions within { }
+
 Wnested-externs
 C ObjC Var(warn_nested_externs) Warning
 Warn about \"extern\" declarations not at file scope
Property changes on: gcc/testsuite/gcc.target/powerpc/ppc-round.c
___________________________________________________________________
Modified: svn:mergeinfo
   Merged /trunk/gcc/testsuite/gcc.target/powerpc/ppc-round.c:r176665

Index: gcc/testsuite/g++.dg/cpp0x/initlist5.C
===================================================================
--- gcc/testsuite/g++.dg/cpp0x/initlist5.C	(revision 180783)
+++ gcc/testsuite/g++.dg/cpp0x/initlist5.C	(working copy)
@@ -1,5 +1,5 @@
 // Test for narrowing diagnostics
-// { dg-options "-std=c++0x" }
+// { dg-options "-std=c++0x -pedantic-errors" }
 
 #include <initializer_list>
 
Index: gcc/testsuite/g++.dg/cpp0x/initlist7.C
===================================================================
--- gcc/testsuite/g++.dg/cpp0x/initlist7.C	(revision 180783)
+++ gcc/testsuite/g++.dg/cpp0x/initlist7.C	(working copy)
@@ -1,5 +1,5 @@
 // PR c++/37932
-// { dg-options "-std=c++0x" }
+// { dg-options "-std=c++0x -pedantic-errors" }
 
 typedef enum { AA=1, BB=2 } my_enum;
 
Index: gcc/testsuite/g++.dg/cpp0x/initlist17.C
===================================================================
--- gcc/testsuite/g++.dg/cpp0x/initlist17.C	(revision 180783)
+++ gcc/testsuite/g++.dg/cpp0x/initlist17.C	(working copy)
@@ -1,4 +1,4 @@
-// { dg-options "-std=c++0x" }
+// { dg-options "-std=c++0x -pedantic-errors" }
 
 void f(int i);
 
Index: gcc/testsuite/g++.dg/cpp0x/initlist36.C
===================================================================
--- gcc/testsuite/g++.dg/cpp0x/initlist36.C	(revision 180783)
+++ gcc/testsuite/g++.dg/cpp0x/initlist36.C	(working copy)
@@ -1,5 +1,5 @@
 // PR c++/44358
-// { dg-options "-std=c++0x" }
+// { dg-options "-std=c++0x -pedantic-errors" }
 
 #include <initializer_list>
 
Index: gcc/cp/typeck2.c
===================================================================
--- gcc/cp/typeck2.c	(revision 180783)
+++ gcc/cp/typeck2.c	(working copy)
@@ -733,7 +733,7 @@
   bool ok = true;
   REAL_VALUE_TYPE d;
 
-  if (!ARITHMETIC_TYPE_P (type))
+  if (!warn_narrowing || !ARITHMETIC_TYPE_P (type))
     return;
 
   init = maybe_constant_value (init);
@@ -781,8 +781,8 @@
     }
 
   if (!ok)
-    permerror (input_location, "narrowing conversion of %qE from %qT to %qT inside { }",
-	       init, ftype, type);
+    pedwarn (input_location, OPT_Wnarrowing, "narrowing conversion of %qE "
+	     "from %qT to %qT inside { }", init, ftype, type);
 }
 
 /* Process the initializer INIT for a variable of type TYPE, emitting
Property changes on: gcc/config/rs6000/rs6000.c
___________________________________________________________________
Modified: svn:mergeinfo
   Merged /trunk/gcc/config/rs6000/rs6000.c:r176665


Property changes on: gcc/config/rs6000/rs6000.h
___________________________________________________________________
Modified: svn:mergeinfo
   Merged /trunk/gcc/config/rs6000/rs6000.h:r176665