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Marc Dietrich

2015-Feb-17 09:40 UTC

[LLVMdev] [PATCH 0/2 v3] add visibility hidden to tls entry points

Patch 1 adds a check for the compilers visibility macro to configure.ac.
Patch 2 avoids redefined symbol errors in clang of the tls entry points. 
Based on a suggestion from Rafael Ávila de Espíndola <rafael.espindola at
gmail.com>
in http://llvm.org/bugs/show_bug.cgi?id=19778.

Tested with gcc 4.9 and clang 3.6(rc)

Marc Dietrich (2):
  configure: add visibility macro detection to configure
  add visibility hidden to tls entry points

 configure.ac                | 28 ++++++----------------------
 src/mapi/Makefile.am        |  1 +
 src/mapi/entry_x86-64_tls.h |  4 ++--
 src/mapi/entry_x86_tls.h    |  5 +++--
 src/mapi/entry_x86_tsd.h    |  5 +++--
 src/util/macros.h           |  6 ++++++
 6 files changed, 21 insertions(+), 28 deletions(-)

-- 
2.2.2

Marc Dietrich

2015-Feb-17 09:40 UTC

head link

[LLVMdev] [PATCH 1/2 v3] configure: add visibility macro detection to configure

This adds clang/gcc visibility macro detection to configure and util/macros.h.
This is can be used to conveniently add e.g. a "HIDDEN" attribute to a
function.

Signed-off-by: Marc Dietrich <marvin24 at gmx.de>
---
v2: use VISIBILITY_*FLAGS instead of *FLAGS directly
v3: no change

 configure.ac      | 28 ++++++----------------------
 src/util/macros.h |  6 ++++++
 2 files changed, 12 insertions(+), 22 deletions(-)

diff --git a/configure.ac b/configure.ac
index 351027b..266764a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -189,6 +189,7 @@ AX_GCC_FUNC_ATTRIBUTE([flatten])
 AX_GCC_FUNC_ATTRIBUTE([format])
 AX_GCC_FUNC_ATTRIBUTE([malloc])
 AX_GCC_FUNC_ATTRIBUTE([packed])
+AX_GCC_FUNC_ATTRIBUTE([visibility])
 
 AM_CONDITIONAL([GEN_ASM_OFFSETS], test "x$GEN_ASM_OFFSETS" = xyes)
 
@@ -245,17 +246,13 @@ if test "x$GCC" = xyes; then
 		   AC_MSG_RESULT([yes]),
 		   [CFLAGS="$save_CFLAGS -Wmissing-prototypes";
 		    AC_MSG_RESULT([no])]);
+    CFLAGS=$save_CFLAGS
 
     # Enable -fvisibility=hidden if using a gcc that supports it
-    save_CFLAGS="$CFLAGS"
-    AC_MSG_CHECKING([whether $CC supports -fvisibility=hidden])
-    VISIBILITY_CFLAGS="-fvisibility=hidden"
-    CFLAGS="$CFLAGS $VISIBILITY_CFLAGS"
-    AC_LINK_IFELSE([AC_LANG_PROGRAM()], AC_MSG_RESULT([yes]),
-		   [VISIBILITY_CFLAGS=""; AC_MSG_RESULT([no])]);
-
-    # Restore CFLAGS; VISIBILITY_CFLAGS are added to it where needed.
-    CFLAGS=$save_CFLAGS
+    if test "x${ax_cv_have_func_attribute_visibility}" = xyes; then
+	VISIBILITY_CFLAGS="-fvisibility=hidden"
+	VISIBILITY_CXXFLAGS="-fvisibility=hidden"
+    fi
 
     # Work around aliasing bugs - developers should comment this out
     CFLAGS="$CFLAGS -fno-strict-aliasing"
@@ -267,19 +264,6 @@ fi
 if test "x$GXX" = xyes; then
     CXXFLAGS="$CXXFLAGS -Wall"
 
-    # Enable -fvisibility=hidden if using a gcc that supports it
-    save_CXXFLAGS="$CXXFLAGS"
-    AC_MSG_CHECKING([whether $CXX supports -fvisibility=hidden])
-    VISIBILITY_CXXFLAGS="-fvisibility=hidden"
-    CXXFLAGS="$CXXFLAGS $VISIBILITY_CXXFLAGS"
-    AC_LANG_PUSH([C++])
-    AC_LINK_IFELSE([AC_LANG_PROGRAM()], AC_MSG_RESULT([yes]),
-		   [VISIBILITY_CXXFLAGS="" ; AC_MSG_RESULT([no])]);
-    AC_LANG_POP([C++])
-
-    # Restore CXXFLAGS; VISIBILITY_CXXFLAGS are added to it where needed.
-    CXXFLAGS=$save_CXXFLAGS
-
     # Work around aliasing bugs - developers should comment this out
     CXXFLAGS="$CXXFLAGS -fno-strict-aliasing"
 
diff --git a/src/util/macros.h b/src/util/macros.h
index eec8b93..7682511 100644
--- a/src/util/macros.h
+++ b/src/util/macros.h
@@ -117,6 +117,12 @@ do {                       \
 #define PRINTFLIKE(f, a)
 #endif
 
+#ifdef HAVE_FUNC_ATTRIBUTE_VISIBILITY
+#define HIDDEN __attribute__((visibility("hidden")))
+#else
+#define HIDDEN
+#endif
+
 #ifdef HAVE_FUNC_ATTRIBUTE_MALLOC
 #define MALLOCLIKE __attribute__((__malloc__))
 #else
-- 
2.2.2

Marc Dietrich

2015-Feb-17 09:40 UTC

head link

[LLVMdev] [PATCH 2/2 v3] add visibility hidden to tls entry points

Avoid redefined symbol errors in clang. Based on a suggestion from
Rafael Ãvila de EspÃndola <rafael.espindola at gmail.com> in
http://llvm.org/bugs/show_bug.cgi?id=19778.

Signed-off-by: Marc Dietrich <marvin24 at gmx.de>
---
v2: - no change
v3: - include util directory in Makefile.am in order to avoid relative
      include paths,
    - make tls entry points array const

 src/mapi/Makefile.am        | 1 +
 src/mapi/entry_x86-64_tls.h | 4 ++--
 src/mapi/entry_x86_tls.h    | 5 +++--
 src/mapi/entry_x86_tsd.h    | 5 +++--
 4 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/src/mapi/Makefile.am b/src/mapi/Makefile.am
index 6794682..c42ed52 100644
--- a/src/mapi/Makefile.am
+++ b/src/mapi/Makefile.am
@@ -45,6 +45,7 @@ AM_CPPFLAGS =							\
 	$(SELINUX_CFLAGS)					\
 	-I$(top_srcdir)/include					\
 	-I$(top_srcdir)/src/mapi				\
+	-I$(top_srcdir)/src/util				\
 	-I$(top_builddir)/src/mapi
 
 include Makefile.sources
diff --git a/src/mapi/entry_x86-64_tls.h b/src/mapi/entry_x86-64_tls.h
index 71e9d60..2c5d64d 100644
--- a/src/mapi/entry_x86-64_tls.h
+++ b/src/mapi/entry_x86-64_tls.h
@@ -25,6 +25,7 @@
  *    Chia-I Wu <olv at lunarg.com>
  */
 
+#include "macros.h"
 #include "u_macros.h"
 
 __asm__(".text\n"
@@ -62,8 +63,7 @@ entry_patch_public(void)
 {
 }
 
-static char
-x86_64_entry_start[];
+extern const char HIDDEN x86_64_entry_start[];
 
 mapi_func
 entry_get_public(int slot)
diff --git a/src/mapi/entry_x86_tls.h b/src/mapi/entry_x86_tls.h
index fa7bc15..a66edec 100644
--- a/src/mapi/entry_x86_tls.h
+++ b/src/mapi/entry_x86_tls.h
@@ -26,6 +26,7 @@
  */
 
 #include <string.h>
+#include "macros.h"
 #include "u_macros.h"
 
 __asm__(".text");
@@ -72,8 +73,8 @@ __asm__(".text");
 extern unsigned long
 x86_current_tls();
 
-static char x86_entry_start[];
-static char x86_entry_end[];
+extern const char HIDDEN x86_entry_start[];
+extern const char HIDDEN x86_entry_end[];
 
 void
 entry_patch_public(void)
diff --git a/src/mapi/entry_x86_tsd.h b/src/mapi/entry_x86_tsd.h
index ece00fa..1de2991 100644
--- a/src/mapi/entry_x86_tsd.h
+++ b/src/mapi/entry_x86_tsd.h
@@ -25,6 +25,7 @@
  *    Chia-I Wu <olv at lunarg.com>
  */
 
+#include "macros.h"
 #include "u_macros.h"
 
 #define X86_ENTRY_SIZE 32
@@ -59,8 +60,8 @@ __asm__(".balign 32\n"
 #include <string.h>
 #include "u_execmem.h"
 
-static const char x86_entry_start[];
-static const char x86_entry_end[];
+extern const char HIDDEN x86_entry_start[];
+extern const char HIDDEN x86_entry_end[];
 
 void
 entry_patch_public(void)
-- 
2.2.2

Sedat Dilek

2015-Feb-17 10:00 UTC

head link

[LLVMdev] [PATCH 1/2 v3] configure: add visibility macro detection to configure

On Tue, Feb 17, 2015 at 10:40 AM, Marc Dietrich <marvin24 at gmx.de>
wrote:> This adds clang/gcc visibility macro detection to configure and
util/macros.h.
> This is can be used to conveniently add e.g. a "HIDDEN" attribute
to a function.
>
> Signed-off-by: Marc Dietrich <marvin24 at gmx.de>
> ---
> v2: use VISIBILITY_*FLAGS instead of *FLAGS directly
> v3: no change
>
>  configure.ac      | 28 ++++++----------------------
>  src/util/macros.h |  6 ++++++
>  2 files changed, 12 insertions(+), 22 deletions(-)
>
> diff --git a/configure.ac b/configure.ac
> index 351027b..266764a 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -189,6 +189,7 @@ AX_GCC_FUNC_ATTRIBUTE([flatten])
>  AX_GCC_FUNC_ATTRIBUTE([format])
>  AX_GCC_FUNC_ATTRIBUTE([malloc])
>  AX_GCC_FUNC_ATTRIBUTE([packed])
> +AX_GCC_FUNC_ATTRIBUTE([visibility])
>
>  AM_CONDITIONAL([GEN_ASM_OFFSETS], test "x$GEN_ASM_OFFSETS" =
xyes)
>
> @@ -245,17 +246,13 @@ if test "x$GCC" = xyes; then
>                    AC_MSG_RESULT([yes]),
>                    [CFLAGS="$save_CFLAGS -Wmissing-prototypes";
>                     AC_MSG_RESULT([no])]);
> +    CFLAGS=$save_CFLAGS
>
>      # Enable -fvisibility=hidden if using a gcc that supports it
Can you restore this comment with a general pointer to "...compiler
that support it".

BTW, what is the compiler option called for clang to suppress
visibility(-hiden) feature - ... -fvisibility=no ?
I would like to test w/o your patches.

- Sedat -
> -    save_CFLAGS="$CFLAGS"
> -    AC_MSG_CHECKING([whether $CC supports -fvisibility=hidden])
> -    VISIBILITY_CFLAGS="-fvisibility=hidden"
> -    CFLAGS="$CFLAGS $VISIBILITY_CFLAGS"
> -    AC_LINK_IFELSE([AC_LANG_PROGRAM()], AC_MSG_RESULT([yes]),
> -                  [VISIBILITY_CFLAGS=""; AC_MSG_RESULT([no])]);
> -
> -    # Restore CFLAGS; VISIBILITY_CFLAGS are added to it where needed.
> -    CFLAGS=$save_CFLAGS
> +    if test "x${ax_cv_have_func_attribute_visibility}" = xyes;
then
> +       VISIBILITY_CFLAGS="-fvisibility=hidden"
> +       VISIBILITY_CXXFLAGS="-fvisibility=hidden"
> +    fi
>
>      # Work around aliasing bugs - developers should comment this out
>      CFLAGS="$CFLAGS -fno-strict-aliasing"
> @@ -267,19 +264,6 @@ fi
>  if test "x$GXX" = xyes; then
>      CXXFLAGS="$CXXFLAGS -Wall"
>
> -    # Enable -fvisibility=hidden if using a gcc that supports it
> -    save_CXXFLAGS="$CXXFLAGS"
> -    AC_MSG_CHECKING([whether $CXX supports -fvisibility=hidden])
> -    VISIBILITY_CXXFLAGS="-fvisibility=hidden"
> -    CXXFLAGS="$CXXFLAGS $VISIBILITY_CXXFLAGS"
> -    AC_LANG_PUSH([C++])
> -    AC_LINK_IFELSE([AC_LANG_PROGRAM()], AC_MSG_RESULT([yes]),
> -                  [VISIBILITY_CXXFLAGS="" ;
AC_MSG_RESULT([no])]);
> -    AC_LANG_POP([C++])
> -
> -    # Restore CXXFLAGS; VISIBILITY_CXXFLAGS are added to it where needed.
> -    CXXFLAGS=$save_CXXFLAGS
> -
>      # Work around aliasing bugs - developers should comment this out
>      CXXFLAGS="$CXXFLAGS -fno-strict-aliasing"
>
> diff --git a/src/util/macros.h b/src/util/macros.h
> index eec8b93..7682511 100644
> --- a/src/util/macros.h
> +++ b/src/util/macros.h
> @@ -117,6 +117,12 @@ do {                       \
>  #define PRINTFLIKE(f, a)
>  #endif
>
> +#ifdef HAVE_FUNC_ATTRIBUTE_VISIBILITY
> +#define HIDDEN __attribute__((visibility("hidden")))
> +#else
> +#define HIDDEN
> +#endif
> +
>  #ifdef HAVE_FUNC_ATTRIBUTE_MALLOC
>  #define MALLOCLIKE __attribute__((__malloc__))
>  #else
> --
> 2.2.2
>

Sedat Dilek

2015-Feb-17 10:58 UTC

head link

[LLVMdev] [PATCH 2/2 v3] add visibility hidden to tls entry points

On Tue, Feb 17, 2015 at 10:40 AM, Marc Dietrich <marvin24 at gmx.de>
wrote:> Avoid redefined symbol errors in clang. Based on a suggestion from
> Rafael Ávila de Espíndola <rafael.espindola at gmail.com> in
> http://llvm.org/bugs/show_bug.cgi?id=19778.
>
> Signed-off-by: Marc Dietrich <marvin24 at gmx.de>
> ---
> v2: - no change
> v3: - include util directory in Makefile.am in order to avoid relative
>       include paths,
>     - make tls entry points array const
>
I adapted this patch as v4 to fit mesa v10.4.4, but it fails (see
log-file in attached tarball).

- Sedat -
>  src/mapi/Makefile.am        | 1 +
>  src/mapi/entry_x86-64_tls.h | 4 ++--
>  src/mapi/entry_x86_tls.h    | 5 +++--
>  src/mapi/entry_x86_tsd.h    | 5 +++--
>  4 files changed, 9 insertions(+), 6 deletions(-)
>
> diff --git a/src/mapi/Makefile.am b/src/mapi/Makefile.am
> index 6794682..c42ed52 100644
> --- a/src/mapi/Makefile.am
> +++ b/src/mapi/Makefile.am
> @@ -45,6 +45,7 @@ AM_CPPFLAGS =                                            
\
>         $(SELINUX_CFLAGS)                                       \
>         -I$(top_srcdir)/include                                 \
>         -I$(top_srcdir)/src/mapi                                \
> +       -I$(top_srcdir)/src/util                                \
>         -I$(top_builddir)/src/mapi
>
>  include Makefile.sources
> diff --git a/src/mapi/entry_x86-64_tls.h b/src/mapi/entry_x86-64_tls.h
> index 71e9d60..2c5d64d 100644
> --- a/src/mapi/entry_x86-64_tls.h
> +++ b/src/mapi/entry_x86-64_tls.h
> @@ -25,6 +25,7 @@
>   *    Chia-I Wu <olv at lunarg.com>
>   */
>
> +#include "macros.h"
>  #include "u_macros.h"
>
>  __asm__(".text\n"
> @@ -62,8 +63,7 @@ entry_patch_public(void)
>  {
>  }
>
> -static char
> -x86_64_entry_start[];
> +extern const char HIDDEN x86_64_entry_start[];
>
>  mapi_func
>  entry_get_public(int slot)
> diff --git a/src/mapi/entry_x86_tls.h b/src/mapi/entry_x86_tls.h
> index fa7bc15..a66edec 100644
> --- a/src/mapi/entry_x86_tls.h
> +++ b/src/mapi/entry_x86_tls.h
> @@ -26,6 +26,7 @@
>   */
>
>  #include <string.h>
> +#include "macros.h"
>  #include "u_macros.h"
>
>  __asm__(".text");
> @@ -72,8 +73,8 @@ __asm__(".text");
>  extern unsigned long
>  x86_current_tls();
>
> -static char x86_entry_start[];
> -static char x86_entry_end[];
> +extern const char HIDDEN x86_entry_start[];
> +extern const char HIDDEN x86_entry_end[];
>
>  void
>  entry_patch_public(void)
> diff --git a/src/mapi/entry_x86_tsd.h b/src/mapi/entry_x86_tsd.h
> index ece00fa..1de2991 100644
> --- a/src/mapi/entry_x86_tsd.h
> +++ b/src/mapi/entry_x86_tsd.h
> @@ -25,6 +25,7 @@
>   *    Chia-I Wu <olv at lunarg.com>
>   */
>
> +#include "macros.h"
>  #include "u_macros.h"
>
>  #define X86_ENTRY_SIZE 32
> @@ -59,8 +60,8 @@ __asm__(".balign 32\n"
>  #include <string.h>
>  #include "u_execmem.h"
>
> -static const char x86_entry_start[];
> -static const char x86_entry_end[];
> +extern const char HIDDEN x86_entry_start[];
> +extern const char HIDDEN x86_entry_end[];
>
>  void
>  entry_patch_public(void)
> --
> 2.2.2
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Sedat Dilek

2015-Feb-17 12:55 UTC

head link

[LLVMdev] [PATCH 0/2 v3] add visibility hidden to tls entry points

On Tue, Feb 17, 2015 at 10:40 AM, Marc Dietrich <marvin24 at gmx.de>
wrote:> Patch 1 adds a check for the compilers visibility macro to configure.ac.
> Patch 2 avoids redefined symbol errors in clang of the tls entry points.
> Based on a suggestion from Rafael Ávila de Espíndola <rafael.espindola
at gmail.com>
> in http://llvm.org/bugs/show_bug.cgi?id=19778.
>
> Tested with gcc 4.9 and clang 3.6(rc)
>
> Marc Dietrich (2):
>   configure: add visibility macro detection to configure
>   add visibility hidden to tls entry points
>
>  configure.ac                | 28 ++++++----------------------
>  src/mapi/Makefile.am        |  1 +
>  src/mapi/entry_x86-64_tls.h |  4 ++--
>  src/mapi/entry_x86_tls.h    |  5 +++--
>  src/mapi/entry_x86_tsd.h    |  5 +++--
>  src/util/macros.h           |  6 ++++++
>  6 files changed, 21 insertions(+), 28 deletions(-)
>
Tested-by: Sedat Dilek <sedat.dilek at gmail.com> (mesa v10.4.4 with
llvm-toolchain v3.6.0rc2)

- Sedat -
> --
> 2.2.2
>

Sedat Dilek

2015-Feb-20 12:45 UTC

head link

[LLVMdev] [PATCH 0/2 v3] add visibility hidden to tls entry points

On Tue, Feb 17, 2015 at 1:55 PM, Sedat Dilek <sedat.dilek at gmail.com>
wrote:> On Tue, Feb 17, 2015 at 10:40 AM, Marc Dietrich <marvin24 at gmx.de>
wrote:
>> Patch 1 adds a check for the compilers visibility macro to
configure.ac.
>> Patch 2 avoids redefined symbol errors in clang of the tls entry
points.
>> Based on a suggestion from Rafael Ávila de Espíndola
<rafael.espindola at gmail.com>
>> in http://llvm.org/bugs/show_bug.cgi?id=19778.
>>
>> Tested with gcc 4.9 and clang 3.6(rc)
>>
>> Marc Dietrich (2):
>>   configure: add visibility macro detection to configure
>>   add visibility hidden to tls entry points
>>
>>  configure.ac                | 28 ++++++----------------------
>>  src/mapi/Makefile.am        |  1 +
>>  src/mapi/entry_x86-64_tls.h |  4 ++--
>>  src/mapi/entry_x86_tls.h    |  5 +++--
>>  src/mapi/entry_x86_tsd.h    |  5 +++--
>>  src/util/macros.h           |  6 ++++++
>>  6 files changed, 21 insertions(+), 28 deletions(-)
>>
>
> Tested-by: Sedat Dilek <sedat.dilek at gmail.com> (mesa v10.4.4 with
> llvm-toolchain v3.6.0rc2)
>
Tested-by: Sedat Dilek <sedat.dilek at gmail.com> (mesa v10.4.4 with
llvm-toolchain v3.6.0rc*3* with compiler-rt)

I re-compiled my Linux graphics driver stack with a self-compiled
llvm-toolchain v3.6.0rc3.

libdrm: v2.4.59
mesa: v10.4.4 (plus gallivm-fixes and visibility-macro-detection
support) + configure: --enable-glx-tls
intel-ddx: v2.99.917-149-g09b0ab9b4384

What about renaming your patches to...?

1/2: "configure: add visibility macro detection"
2/2: "mapi: add visibility hidden to tls entry points"

Even 1/2 should reflect it's a code-generation option for compilers
like GCC or LLVM/Clang.
It's up2u.
Please have a look at [1], too.

Thanks.

- Sedat -

[1] https://gcc.gnu.org/onlinedocs/gcc/Code-Gen-Options.html ->
"-fvisibility=[default|internal|hidden|protected]"
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Emil Velikov

2015-Feb-26 14:44 UTC

head link

[LLVMdev] [Mesa-dev] [PATCH 1/2 v3] configure: add visibility macro detection to configure

Hi Marc

On 17/02/15 09:40, Marc Dietrich wrote:> This adds clang/gcc visibility macro detection to configure and
util/macros.h.
> This is can be used to conveniently add e.g. a "HIDDEN" attribute
to a function.
> I believe this should be OK to go in regardless of the status of patch
2. There are just a couple of trivial nitpicks.
> Signed-off-by: Marc Dietrich <marvin24 at gmx.de>
> ---
> v2: use VISIBILITY_*FLAGS instead of *FLAGS directly
> v3: no change
> 
>  configure.ac      | 28 ++++++----------------------
>  src/util/macros.h |  6 ++++++
>  2 files changed, 12 insertions(+), 22 deletions(-)
> 
> diff --git a/configure.ac b/configure.ac
> index 351027b..266764a 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -189,6 +189,7 @@ AX_GCC_FUNC_ATTRIBUTE([flatten])
>  AX_GCC_FUNC_ATTRIBUTE([format])
>  AX_GCC_FUNC_ATTRIBUTE([malloc])
>  AX_GCC_FUNC_ATTRIBUTE([packed])
> +AX_GCC_FUNC_ATTRIBUTE([visibility])
>  
>  AM_CONDITIONAL([GEN_ASM_OFFSETS], test "x$GEN_ASM_OFFSETS" =
xyes)
>  
> @@ -245,17 +246,13 @@ if test "x$GCC" = xyes; then
>  		   AC_MSG_RESULT([yes]),
>  		   [CFLAGS="$save_CFLAGS -Wmissing-prototypes";
>  		    AC_MSG_RESULT([no])]);
> +    CFLAGS=$save_CFLAGS
>  I'm not sure we want/need this one ?
>      # Enable -fvisibility=hidden if using a gcc that supports itAs spotted by Sedat, please update the comment.
> -    save_CFLAGS="$CFLAGS"
> -    AC_MSG_CHECKING([whether $CC supports -fvisibility=hidden])
> -    VISIBILITY_CFLAGS="-fvisibility=hidden"
> -    CFLAGS="$CFLAGS $VISIBILITY_CFLAGS"
> -    AC_LINK_IFELSE([AC_LANG_PROGRAM()], AC_MSG_RESULT([yes]),
> -		   [VISIBILITY_CFLAGS=""; AC_MSG_RESULT([no])]);
> -
> -    # Restore CFLAGS; VISIBILITY_CFLAGS are added to it where needed.
> -    CFLAGS=$save_CFLAGS
> +    if test "x${ax_cv_have_func_attribute_visibility}" = xyes;
then
> +	VISIBILITY_CFLAGS="-fvisibility=hidden"
> +	VISIBILITY_CXXFLAGS="-fvisibility=hidden"
> +    fi
>  As these two are no longer GCC "specific" we can move them out of the
if
test x$GCC = xyes, conditional.

>      # Work around aliasing bugs - developers should comment this out
>      CFLAGS="$CFLAGS -fno-strict-aliasing"
> @@ -267,19 +264,6 @@ fi
>  if test "x$GXX" = xyes; then
>      CXXFLAGS="$CXXFLAGS -Wall"
>  
> -    # Enable -fvisibility=hidden if using a gcc that supports it
> -    save_CXXFLAGS="$CXXFLAGS"
> -    AC_MSG_CHECKING([whether $CXX supports -fvisibility=hidden])
> -    VISIBILITY_CXXFLAGS="-fvisibility=hidden"
> -    CXXFLAGS="$CXXFLAGS $VISIBILITY_CXXFLAGS"
> -    AC_LANG_PUSH([C++])
> -    AC_LINK_IFELSE([AC_LANG_PROGRAM()], AC_MSG_RESULT([yes]),
> -		   [VISIBILITY_CXXFLAGS="" ; AC_MSG_RESULT([no])]);
> -    AC_LANG_POP([C++])
> -
> -    # Restore CXXFLAGS; VISIBILITY_CXXFLAGS are added to it where needed.
> -    CXXFLAGS=$save_CXXFLAGS
> -
>      # Work around aliasing bugs - developers should comment this out
>      CXXFLAGS="$CXXFLAGS -fno-strict-aliasing"
>  
> diff --git a/src/util/macros.h b/src/util/macros.h
> index eec8b93..7682511 100644
> --- a/src/util/macros.h
> +++ b/src/util/macros.h
> @@ -117,6 +117,12 @@ do {                       \
>  #define PRINTFLIKE(f, a)
>  #endif
>  
> +#ifdef HAVE_FUNC_ATTRIBUTE_VISIBILITY
> +#define HIDDEN __attribute__((visibility("hidden")))
> +#else
> +#define HIDDEN
> +#endif
> +We already define HIDDEN in the asm code.

Can you check (build or otherwise) that things don't clash for
--enable-asm and --{en,dis}able-shared-glapi. Check the configure log,
as we conveniently toggle the latter.

Thanks
Emil

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