2011-11-02 Paolo Carlini <paolo.carlini@oracle.com>

	PR c++/50956
	* builtins.c (fold_builtin_memchr): Fix cast.

/cp
2011-11-02  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/50956
	* typeck.c (build_const_cast_1): Fix -Wcast-qual for false
	comp_ptr_ttypes_const.

/testsuite
2011-11-02  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/50956
	* g++.dg/warn/Wcast-qual2.C: New.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@180786 138bc75d-0d04-0410-961f-82ee72b054a4

6 files changed, 53 insertions, 26 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 70ae866463f..fe07de1b70f 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2011-11-02  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/50956
+	* builtins.c (fold_builtin_memchr): Fix cast.
+
 2011-11-02  Teresa Johnson  <tejohnson@google.com>
 
 	* config/i386/predicates.md (promotable_binary_operator): Add minus
diff --git a/gcc/builtins.c b/gcc/builtins.c
index 51d7b12e687..bad31659a83 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -8427,7 +8427,7 @@ fold_builtin_memchr (location_t loc, tree arg1, tree arg2, tree len, tree type)
 	  if (target_char_cast (arg2, &c))
 	    return NULL_TREE;
 
-	  r = (char *) memchr (p1, c, tree_low_cst (len, 1));
+	  r = (const char *) memchr (p1, c, tree_low_cst (len, 1));
 
 	  if (r == NULL)
 	    return build_int_cst (TREE_TYPE (arg1), 0);
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index d246e5cc4ba..90651e6e540 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2011-11-02  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/50956
+	* typeck.c (build_const_cast_1): Fix -Wcast-qual for false
+	comp_ptr_ttypes_const.
+
 2011-11-02  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
 
 	* Make-lang.in (g++spec.o): Pass SHLIB instead of SHLIB_LINK.
diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index 8d70df5eb75..0b1f217a908 100644
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -6345,34 +6345,41 @@ build_const_cast_1 (tree dst_type, tree expr, tsubst_flags_t complain,
 	return error_mark_node;
     }
 
-  if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
-      && comp_ptr_ttypes_const (dst_type, src_type))
+  if (TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
     {
-      if (valid_p)
-	{
-	  *valid_p = true;
-	  /* This cast is actually a C-style cast.  Issue a warning if
-	     the user is making a potentially unsafe cast.  */
-	  check_for_casting_away_constness (src_type, dst_type, CAST_EXPR,
-					    complain);
-	}
-      if (reference_type)
+      if (comp_ptr_ttypes_const (dst_type, src_type))
 	{
-	  expr = cp_build_addr_expr (expr, complain);
-	  expr = build_nop (reference_type, expr);
-	  return convert_from_reference (expr);
-	}
-      else
-	{
-	  expr = decay_conversion (expr);
-	  /* build_c_cast puts on a NOP_EXPR to make the result not an
-	     lvalue.  Strip such NOP_EXPRs if VALUE is being used in
-	     non-lvalue context.  */
-	  if (TREE_CODE (expr) == NOP_EXPR
-	      && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
-	    expr = TREE_OPERAND (expr, 0);
-	  return build_nop (dst_type, expr);
+	  if (valid_p)
+	    {
+	      *valid_p = true;
+	      /* This cast is actually a C-style cast.  Issue a warning if
+		 the user is making a potentially unsafe cast.  */
+	      check_for_casting_away_constness (src_type, dst_type,
+						CAST_EXPR, complain);
+	    }
+	  if (reference_type)
+	    {
+	      expr = cp_build_addr_expr (expr, complain);
+	      expr = build_nop (reference_type, expr);
+	      return convert_from_reference (expr);
+	    }
+	  else
+	    {
+	      expr = decay_conversion (expr);
+	      /* build_c_cast puts on a NOP_EXPR to make the result not an
+		 lvalue.  Strip such NOP_EXPRs if VALUE is being used in
+		 non-lvalue context.  */
+	      if (TREE_CODE (expr) == NOP_EXPR
+		  && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
+		expr = TREE_OPERAND (expr, 0);
+	      return build_nop (dst_type, expr);
+	    }
 	}
+      else if (valid_p
+	       && !at_least_as_qualified_p (TREE_TYPE (dst_type),
+					    TREE_TYPE (src_type)))
+	check_for_casting_away_constness (src_type, dst_type, CAST_EXPR,
+					  complain);
     }
 
   if (complain & tf_error)
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 057fd7c5973..aae9e361144 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2011-11-02  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/50956
+	* g++.dg/warn/Wcast-qual2.C: New.
+
 2011-11-02  Tom de Vries  <tom@codesourcery.com>
 
 	PR tree-optimization/50763
diff --git a/gcc/testsuite/g++.dg/warn/Wcast-qual2.C b/gcc/testsuite/g++.dg/warn/Wcast-qual2.C
new file mode 100644
index 00000000000..23dbb4d39b0
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wcast-qual2.C
@@ -0,0 +1,4 @@
+// PR c++/50956
+// { dg-options "-Wcast-qual" }
+
+void* p = (void*)"txt"; // { dg-warning "cast" }