[C++ Patch] PR 56815

[Paolo Carlini]

Hi,

thus, as discussed in the audit trail, I'm simply changing the permerror 
in the C++ front-end to pedwarn.

Tested x86_64-linux.

Thanks,
Paolo.

PS: there is a couple of issues noticed while working on this - 
essentially, tweaks to c.opt and c-common.c - which I prefer to handle 
separately.

///////////////////////////////
/cp
2013-04-03  Paolo Carlini  <paolo.carl...@oracle.com>

        PR c++/56815
        * typeck.c (cp_build_unary_op): Change -Wpointer-arith permerror to
        pedwarn.

/testsuite
2013-04-03  Paolo Carlini  <paolo.carl...@oracle.com>

        PR c++/56815
        * g++.dg/warn/Wpointer-arith-1.C: New.
        * g++.dg/gomp/for-19.C: Adjust.
Index: cp/typeck.c
===================================================================
--- cp/typeck.c (revision 197414)
+++ cp/typeck.c (working copy)
@@ -5574,15 +5574,16 @@ cp_build_unary_op (enum tree_code code, tree xarg,
                 else
                   return error_mark_node;
               }
-           else if ((pedantic || warn_pointer_arith)
-                    && !TYPE_PTROB_P (argtype)) 
+           else if (!TYPE_PTROB_P (argtype)) 
               {
                 if (complain & tf_error)
-                  permerror (input_location, (code == PREINCREMENT_EXPR
+                  pedwarn (input_location,
+                          pedantic ? OPT_Wpedantic : OPT_Wpointer_arith,
+                          (code == PREINCREMENT_EXPR
                               || code == POSTINCREMENT_EXPR)
-                             ? G_("ISO C++ forbids incrementing a pointer of 
type %qT")
-                             : G_("ISO C++ forbids decrementing a pointer of 
type %qT"),
-                             argtype);
+                          ? G_("ISO C++ forbids incrementing a pointer of type 
%qT")
+                          : G_("ISO C++ forbids decrementing a pointer of type 
%qT"),
+                          argtype);
                 else
                   return error_mark_node;
               }
Index: testsuite/g++.dg/gomp/for-19.C
===================================================================
--- testsuite/g++.dg/gomp/for-19.C      (revision 197414)
+++ testsuite/g++.dg/gomp/for-19.C      (working copy)
@@ -9,7 +9,7 @@ void
 f1 (void)
 {
 #pragma omp for
-  for (void *q = (void *)p; q < (void *) (p + 4); q++) // { dg-error "forbids 
incrementing a pointer of type" }
+  for (void *q = (void *)p; q < (void *) (p + 4); q++) // { dg-warning 
"forbids incrementing a pointer of type" }
     ;
 }
 
@@ -27,7 +27,7 @@ void
 f3 (void)
 {
 #pragma omp for
-  for (T q = T (p); q < T (p + 4); q++)        // { dg-error "forbids 
incrementing a pointer of type" }
+  for (T q = T (p); q < T (p + 4); q++)        // { dg-warning "forbids 
incrementing a pointer of type" }
     ;
 }
 
Index: testsuite/g++.dg/warn/Wpointer-arith-1.C
===================================================================
--- testsuite/g++.dg/warn/Wpointer-arith-1.C    (revision 0)
+++ testsuite/g++.dg/warn/Wpointer-arith-1.C    (working copy)
@@ -0,0 +1,13 @@
+// PR c++/56815
+// { dg-options "-Wpointer-arith" }
+
+int main()
+{
+  void *pv = 0;
+  pv++;    // { dg-warning "forbids incrementing a pointer" }
+
+  typedef void (*pft) ();
+
+  pft pf = 0;
+  pf++;    // { dg-warning "forbids incrementing a pointer" }
+}