re PR c/19978 (overflow in expression of constants should not cause multiple warnings)

2007-01-05  Manuel Lopez-Ibanez  <manu@gcc.gnu.org>

	PR c/19978
	* tree.h (TREE_OVERFLOW_P): New.
	* c-typeck.c (parser_build_unary_op): Warn only if result
	overflowed and operands did not.
	(parser_build_binary_op): Likewise.
	(convert_for_assignment): Remove redundant overflow_warning.
	* c-common.c (overflow_warning): Don't check or set TREE_OVERFLOW.

cp/
	* semantics.c (finish_unary_op_expr): Warn only if result
	overflowed and operands did not.

testsuite/
	* gcc.dg/multiple-overflow-warn-1.c: New.
	* gcc.dg/multiple-overflow-warn-2.c: New.
	* gcc.dg/overflow-warn-6.c: New.
	* g++.dg/warn/multiple-overflow-warn-1.C: New.

From-SVN: r120505

5 files changed, 64 insertions, 0 deletions

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 1890965..5372427 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,11 @@
+2007-01-05  Manuel Lopez-Ibanez  <manu@gcc.gnu.org>
+
+	PR c/19978
+	* gcc.dg/multiple-overflow-warn-1.c: New.
+	* gcc.dg/multiple-overflow-warn-2.c: New.
+	* gcc.dg/overflow-warn-6.c: New.
+	* g++.dg/warn/multiple-overflow-warn-1.C: New.
+	
 2007-01-05  Roger Sayle  <roger@eyesopen.com>
 
 	* gfortran.dg/array_memcpy_1.f90: New test case.
diff --git a/gcc/testsuite/g++.dg/warn/multiple-overflow-warn-1.C b/gcc/testsuite/g++.dg/warn/multiple-overflow-warn-1.C
new file mode 100644
index 0000000..4899302
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/multiple-overflow-warn-1.C
@@ -0,0 +1,13 @@
+/* PR c/19978 : Test for duplicated warnings (unary operators).  */
+/* { dg-do compile } */
+/* { dg-options "-Woverflow" } */
+
+#include <limits.h>
+
+int 
+g (void)
+{
+  return - - - - -INT_MIN; /* { dg-bogus "integer overflow in expression.*integer overflow in expression" } */
+  /* { dg-warning "integer overflow in expression" "" { target *-*-* } 10 } */
+}
+
diff --git a/gcc/testsuite/gcc.dg/multiple-overflow-warn-1.c b/gcc/testsuite/gcc.dg/multiple-overflow-warn-1.c
new file mode 100644
index 0000000..be7b3b8
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/multiple-overflow-warn-1.c
@@ -0,0 +1,13 @@
+/* PR c/19978 : Test for duplicated warnings (unary operators).  */
+/* { dg-do compile } */
+/* { dg-options "-std=c99 -Woverflow" } */
+
+#include <limits.h>
+
+int 
+g (void)
+{
+  return - - - - -INT_MIN; /* { dg-bogus "integer overflow in expression.*integer overflow in expression" } */
+  /* { dg-warning "integer overflow in expression" "" { target *-*-* } 10 } */
+}
+
diff --git a/gcc/testsuite/gcc.dg/multiple-overflow-warn-2.c b/gcc/testsuite/gcc.dg/multiple-overflow-warn-2.c
new file mode 100644
index 0000000..8a4e9e5
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/multiple-overflow-warn-2.c
@@ -0,0 +1,12 @@
+/* PR c/19978 : Test for duplicated warnings (binary operators).  */
+/* { dg-do compile } */
+/* { dg-options "-std=c99 -Woverflow" } */
+
+#include <limits.h>
+
+int 
+g1 (void)
+{
+  return INT_MAX + 1 - INT_MAX; /* { dg-bogus "integer overflow in expression.*integer overflow in expression" } */
+  /* { dg-warning "integer overflow in expression" "" { target *-*-* } 10 } */
+}
diff --git a/gcc/testsuite/gcc.dg/overflow-warn-6.c b/gcc/testsuite/gcc.dg/overflow-warn-6.c
new file mode 100644
index 0000000..da8cb01
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/overflow-warn-6.c
@@ -0,0 +1,18 @@
+/* Test non-constant operands in overflowed expressions.  */
+/* { dg-do compile } */
+/* { dg-options "-std=c99 -Woverflow" } */
+
+#include <limits.h>
+
+int 
+h1 (int x)
+{
+  return x * (0 * (INT_MAX + 1)); /* { dg-warning "warning: integer overflow in expression" } */
+}
+
+int 
+h2 (int x)
+{
+  return ((INT_MAX + 1) * 0) * x; /* { dg-warning "warning: integer overflow in expression" } */
+}
+