From 0173bd2a038cbeef871b22b312a6856ab1dcda2a Mon Sep 17 00:00:00 2001
From: Marek Polacek <polacek@redhat.com>
Date: Thu, 7 May 2015 19:36:31 +0000
Subject: re PR c/65179 (Introduce new C warning: -Wshift-negative-value)

	PR c/65179
	* c-common.c (c_fully_fold_internal): Warn when left shifting a
	negative value.
	* c.opt (Wshift-negative-value): New option.
	* c-opts.c (c_common_post_options): Set warn_shift_negative_value
	when -Wextra and C99/C++11 mode.

	* c-typeck.c (build_binary_op): Warn when left shifting a negative
	value.

	* typeck.c (cp_build_binary_op): Warn when left shifting a negative
	value.

	* doc/invoke.texi: Document -Wshift-negative-value.

	* c-c++-common/Wshift-negative-value-1.c: New test.
	* testsuite/c-c++-common/Wshift-negative-value-2.c: New test.
	* testsuite/c-c++-common/Wshift-negative-value-3.c: New test.
	* testsuite/c-c++-common/Wshift-negative-value-4.c: New test.
	* testsuite/c-c++-common/Wshift-negative-value-5.c: New test.
	* testsuite/c-c++-common/Wshift-negative-value-6.c: New test.
	* testsuite/gcc.dg/c90-left-shift-1.c: New test.
	* testsuite/gcc.dg/c99-const-expr-7.c: Add dg-error.
	* testsuite/gcc.dg/c99-left-shift-1.c: New test.

From-SVN: r222889
---
 gcc/doc/invoke.texi | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

(limited to 'gcc/doc/invoke.texi')

diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 2c58a0d..934edd6 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -271,7 +271,7 @@ Objective-C and Objective-C++ Dialects}.
 -Wpointer-arith  -Wno-pointer-to-int-cast @gol
 -Wredundant-decls  -Wno-return-local-addr @gol
 -Wreturn-type  -Wsequence-point  -Wshadow  -Wno-shadow-ivar @gol
--Wshift-count-negative -Wshift-count-overflow @gol
+-Wshift-count-negative -Wshift-count-overflow -Wshift-negative-value @gol
 -Wsign-compare  -Wsign-conversion -Wfloat-conversion @gol
 -Wsizeof-pointer-memaccess  -Wsizeof-array-argument @gol
 -Wstack-protector -Wstack-usage=@var{len} -Wstrict-aliasing @gol
@@ -3489,6 +3489,7 @@ name is still supported, but the newer name is more descriptive.)
 -Wsign-compare  @gol
 -Wtype-limits  @gol
 -Wuninitialized  @gol
+-Wshift-negative-value  @gol
 -Wunused-parameter @r{(only with} @option{-Wunused} @r{or} @option{-Wall}@r{)} @gol
 -Wunused-but-set-parameter @r{(only with} @option{-Wunused} @r{or} @option{-Wall}@r{)}  @gol
 }
@@ -3922,6 +3923,12 @@ Warn if shift count is negative. This warning is enabled by default.
 @opindex Wno-shift-count-overflow
 Warn if shift count >= width of type. This warning is enabled by default.
 
+@item -Wshift-negative-value
+@opindex Wshift-negative-value
+@opindex Wno-shift-negative-value
+Warn if left shifting a negative value.  This warning is enabled by
+@option{-Wextra} in C99 and C++11 modes (and newer).
+
 @item -Wswitch
 @opindex Wswitch
 @opindex Wno-switch
-- 
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