From ac2121bf962ecc054dd103ccd42a93912051672e Mon Sep 17 00:00:00 2001 From: Kamil Dudka Date: Tue, 21 Jun 2016 12:40:26 +0200 Subject: [PATCH] curl-compilers.m4: improve detection of GCC's -fvisibility= flag Some builds of GCC produce output on both stdout and stderr when --help --verbose is used. The 2>&1 redirection caused them to be arbitrarily interleaved with each other because of stream buffering. Consequently, grep failed to match the fvisibility= string in the mixed output, even though the string was present in GCC's standard output. This led to silently disabling symbol hiding in some builds of curl. Upstream-commit: b2dcf0347f1ee5041cccd64632bb8dd7ccbbae91 Signed-off-by: Kamil Dudka --- configure | 2 +- m4/curl-compilers.m4 | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/configure b/configure index 4797e02..fc260ee 100755 --- a/configure +++ b/configure @@ -17636,7 +17636,7 @@ $as_echo_n "checking if compiler supports hiding library internal symbols... " > ;; GNU_C) if test "$compiler_num" -ge "304"; then - if $CC --help --verbose 2>&1 | grep fvisibility= > /dev/null ; then + if $CC --help --verbose 2>/dev/null | grep fvisibility= >/dev/null ; then tmp_EXTERN="__attribute__ ((__visibility__ (\"default\")))" tmp_CFLAGS="-fvisibility=hidden" supports_symbol_hiding="yes" diff --git a/m4/curl-compilers.m4 b/m4/curl-compilers.m4 index ca064dd..77371de 100644 --- a/m4/curl-compilers.m4 +++ b/m4/curl-compilers.m4 @@ -21,7 +21,7 @@ #*************************************************************************** # File version for 'aclocal' use. Keep it a single number. -# serial 65 +# serial 66 dnl CURL_CHECK_COMPILER @@ -1391,7 +1391,7 @@ AC_DEFUN([CURL_CHECK_COMPILER_SYMBOL_HIDING], [ GNU_C) dnl Only gcc 3.4 or later if test "$compiler_num" -ge "304"; then - if $CC --help --verbose 2>&1 | grep fvisibility= > /dev/null ; then + if $CC --help --verbose 2>/dev/null | grep fvisibility= >/dev/null ; then tmp_EXTERN="__attribute__ ((__visibility__ (\"default\")))" tmp_CFLAGS="-fvisibility=hidden" supports_symbol_hiding="yes" -- 2.5.5