From d52a222f8bc6b707abd87e9c3fadbe720a735065 Mon Sep 17 00:00:00 2001
From: Julian Seward <jseward@acm.org>
Date: Thu, 30 Mar 2017 12:14:23 +0000
Subject: [PATCH] Bug 358697 - valgrind.h: Some code remains even when defining
 NVALGRIND. Patch from Matthias Schwarzott (zzam@gentoo.org).  The patch
 removes a volatile memory read which was only there to stop compilers warning
 about |format| being unused.

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@16290
---
 include/valgrind.h                       | 4 ++--
 none/tests/Makefile.am                   | 5 +++++
 none/tests/vgprintf_nvalgrind.stderr.exp | 4 ++++
 none/tests/vgprintf_nvalgrind.vgtest     | 1 +
 4 files changed, 12 insertions(+), 2 deletions(-)
 create mode 100644 none/tests/vgprintf_nvalgrind.stderr.exp
 create mode 100644 none/tests/vgprintf_nvalgrind.vgtest

diff --git a/include/valgrind.h b/include/valgrind.h
index dc7dca7b8..46168aaa9 100644
--- a/include/valgrind.h
+++ b/include/valgrind.h
@@ -6769,7 +6769,7 @@ __inline
 VALGRIND_PRINTF(const char *format, ...)
 {
 #if defined(NVALGRIND)
-   if (format) *(volatile const char *)format;   /* avoid compiler warning */
+   (void)format;
    return 0;
 #else /* NVALGRIND */
 #if defined(_MSC_VER) || defined(__MINGW64__)
@@ -6808,7 +6808,7 @@ __inline
 VALGRIND_PRINTF_BACKTRACE(const char *format, ...)
 {
 #if defined(NVALGRIND)
-   if (format) *(volatile const char *)format;   /* avoid compiler warning */
+   (void)format;
    return 0;
 #else /* NVALGRIND */
 #if defined(_MSC_VER) || defined(__MINGW64__)
diff --git a/none/tests/Makefile.am b/none/tests/Makefile.am
index 198d5ff2b..548f8f791 100644
--- a/none/tests/Makefile.am
+++ b/none/tests/Makefile.am
@@ -203,6 +203,7 @@ EXTRA_DIST = \
 	tls.vgtest tls.stderr.exp tls.stdout.exp  \
 	unit_debuglog.stderr.exp unit_debuglog.vgtest \
 	vgprintf.stderr.exp vgprintf.vgtest \
+	vgprintf_nvalgrind.stderr.exp vgprintf_nvalgrind.vgtest \
 	process_vm_readv_writev.stderr.exp process_vm_readv_writev.vgtest
 
 check_PROGRAMS = \
@@ -248,6 +249,7 @@ check_PROGRAMS = \
 	unit_debuglog \
 	valgrind_cpp_test \
 	vgprintf \
+	vgprintf_nvalgrind \
 	coolo_sigaction \
 	gxx304 \
 	process_vm_readv_writev
@@ -362,6 +364,9 @@ else
  tls2_so_LDFLAGS	= -shared
 endif
 
+vgprintf_nvalgrind_SOURCES = vgprintf.c
+vgprintf_nvalgrind_CFLAGS = -DNVALGRIND
+
 valgrind_cpp_test_SOURCES = valgrind_cpp_test.cpp
 valgrind_cpp_test_LDADD   = -lstdc++
 
diff --git a/none/tests/vgprintf_nvalgrind.stderr.exp b/none/tests/vgprintf_nvalgrind.stderr.exp
new file mode 100644
index 000000000..0a9dbe695
--- /dev/null
+++ b/none/tests/vgprintf_nvalgrind.stderr.exp
@@ -0,0 +1,4 @@
+
+0
+0
+
diff --git a/none/tests/vgprintf_nvalgrind.vgtest b/none/tests/vgprintf_nvalgrind.vgtest
new file mode 100644
index 000000000..e6e6253b5
--- /dev/null
+++ b/none/tests/vgprintf_nvalgrind.vgtest
@@ -0,0 +1 @@
+prog: vgprintf_nvalgrind