m...@kotelna.sk said:
> a) It'll fail on GCC < 4.0. For this I need to write an autoconf test that
> will check if -fvisibility is actually supported by the compiler and if
> not, just not use it. The parts in the actual source code can check against
> __GNUC_MAJOR__.
>
> Has anyone ever done anything like this with autoconf? How to check if the
> compiler supports some flag is not obvious... Help with auto-kung-fu
> appreciated :-)
>
> b) It *should* work on Windows; there we already use __declspec() so for
> the sake of sanity I guess we should not touch -fvisibility at all?
The attached version should be good to go and resolve a) and b) above.
Unsure if it's good practice to use _LT_COMPULER_OPTION in autoconf tests
but it does appear to work.
-mato
>From 7238b950b766a24d29e5f3fc70d8169a989cf7f7 Mon Sep 17 00:00:00 2001
From: Martin Lucina <m...@kotelna.sk>
Date: Thu, 25 Nov 2010 16:29:40 +0100
Subject: [PATCH] Control symbol exports using -fvisibility
On systems using GCC 4.0 or newer which support symbol visibility in shared
libraries, use -fvisibility=hidden and only export explict API functions
defined in zmq.cpp. We do not enable -fvisibility on MinGW since this uses a
separate mechanism (__declspec).
Signed-off-by: Martin Lucina <m...@kotelna.sk>
---
configure.in | 12 ++++++++++++
include/zmq.h | 8 ++++++++
include/zmq_utils.h | 6 ++++++
src/Makefile.am | 3 +--
src/zmq.cpp | 8 ++++++++
5 files changed, 35 insertions(+), 2 deletions(-)
diff --git a/configure.in b/configure.in
index 27f8bab..b7d524a 100644
--- a/configure.in
+++ b/configure.in
@@ -223,6 +223,18 @@ case "${host_os}" in
;;
esac
+# Check if the compiler supports -fvisibility=hidden. If so, use it, but not
+# on MinGW32 where we use a separate mechanism (__declspec).
+_LT_COMPILER_OPTION([if $compiler supports -fvisibility=hidden],
+ ac_cv_prog_compiler_visibility,
+ [-fvisibility=hidden],
+ [],
+ [have_dso_visibility=yes])
+if test "x$have_dso_visibility" = "xyes" -a "x$on_mingw32" = "xno"; then
+ LIBZMQ_EXTRA_CFLAGS="-fvisibility=hidden $LIBZMQ_EXTRA_CFLAGS"
+ LIBZMQ_EXTRA_CXXFLAGS="-fvisibility=hidden $LIBZMQ_EXTRA_CXXFLAGS"
+fi
+
# CPU-specific optimizations
case "${host_cpu}" in
*sparc*)
diff --git a/include/zmq.h b/include/zmq.h
index c2efa07..7a63253 100644
--- a/include/zmq.h
+++ b/include/zmq.h
@@ -39,6 +39,9 @@ extern "C" {
# endif
#else
# define ZMQ_EXPORT
+# if defined __GNUC__ && __GNUC__ >= 4
+# pragma GCC visibility push(default)
+# endif
#endif
/******************************************************************************/
@@ -242,6 +245,11 @@ ZMQ_EXPORT int zmq_poll (zmq_pollitem_t *items, int nitems, long timeout);
ZMQ_EXPORT int zmq_device (int device, void * insocket, void* outsocket);
+#undef ZMQ_EXPORT
+#if defined __GNUC__ && __GNUC__ >= 4 && !defined _WIN32
+# pragma GCC visibility pop
+#endif
+
#ifdef __cplusplus
}
#endif
diff --git a/include/zmq_utils.h b/include/zmq_utils.h
index 7d8d5fe..6d42bf9 100644
--- a/include/zmq_utils.h
+++ b/include/zmq_utils.h
@@ -33,6 +33,9 @@ extern "C" {
# endif
#else
# define ZMQ_EXPORT
+# if defined __GNUC__ && __GNUC__ >= 4
+# pragma GCC visibility push(default)
+# endif
#endif
/* Helper functions are used by perf tests so that they don't have to care */
@@ -49,6 +52,9 @@ ZMQ_EXPORT unsigned long zmq_stopwatch_stop (void *watch_);
ZMQ_EXPORT void zmq_sleep (int seconds_);
#undef ZMQ_EXPORT
+#if defined __GNUC__ && __GNUC__ >= 4 && !defined _WIN32
+# pragma GCC visibility pop
+#endif
#ifdef __cplusplus
}
diff --git a/src/Makefile.am b/src/Makefile.am
index 761d8e8..a857ee7 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -203,7 +203,6 @@ libpgm_diff_flags = \
-DCONFIG_HAVE_ISO_VARARGS \
-DCONFIG_HAVE_TSC \
-DCONFIG_HAVE_WSACMSGHDR \
- -DCONFIG_HAVE_DSO_VISIBILITY \
-DCONFIG_BIND_INADDR_ANY
else
@@ -225,7 +224,6 @@ libpgm_diff_flags = \
-DCONFIG_HAVE_IP_MREQN \
-DCONFIG_HAVE_SPRINTF_GROUPING \
-DCONFIG_HAVE_VASPRINTF \
- -DCONFIG_HAVE_DSO_VISIBILITY \
-DCONFIG_BIND_INADDR_ANY \
-DCONFIG_HAVE_GETOPT
endif
@@ -237,6 +235,7 @@ libpgm_la_CFLAGS = -I$(top_srcdir)/foreign/openpgm/@pgm_basename@/openpgm/pgm/in
-DCONFIG_16BIT_CHECKSUM \
-DCONFIG_GALOIS_MUL_LUT \
-DGETTEXT_PACKAGE='"pgm"' \
+ -DPGM_GNUC_INTERNAL= \
${libpgm_diff_flags}
libzmq_la_CXXFLAGS = -I$(top_srcdir)/foreign/openpgm/@pgm_basename@/openpgm/pgm/include/ \
diff --git a/src/zmq.cpp b/src/zmq.cpp
index 62e50cd..6a1d396 100644
--- a/src/zmq.cpp
+++ b/src/zmq.cpp
@@ -60,6 +60,10 @@
#include <pgm/pgm.h>
#endif
+#if defined __GNUC__ && __GNUC__ >= 4 && !defined ZMQ_HAVE_WINDOWS
+#pragma GCC visibility push(default)
+#endif
+
void zmq_version (int *major_, int *minor_, int *patch_)
{
*major_ = ZMQ_VERSION_MAJOR;
@@ -725,3 +729,7 @@ unsigned long zmq_stopwatch_stop (void *watch_)
return (unsigned long) (end - start);
}
+#if defined __GNUC__ && __GNUC__ >= 4 && !defined ZMQ_HAVE_WINDOWS
+#pragma GCC visibility pop
+#endif
+
--
1.7.1
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