ref: f4a3255d450e18e4981074ef9a42a2318f9e7cbc
parent: 036bdc0c9a4fb55b4fe5a7276e97b70b95c8a260
author: Alexei Podtelezhnikov <apodtele@gmail.com>
date: Sat Feb 3 19:09:02 EST 2018
[unix] Use -fvisibility=hidden. It is now widely recommended that ELF shared libraries hide symbols except those with explicit __attribute__((visibility("default"))). This is supported by all major compilers and should rather be an option in libtool. * builds/unix/configure.raw: Add -fvisibility=hidden to CFLAGS. * builds/unix/ftconfig.in, builds/vms/ftconfig.h, include/freetype/config/ftconfig.h (FT_EXPORT): Use visibility attribute.
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,17 @@
+2018-02-04 Alexei Podtelezhnikov <apodtele@gmail.com>
+
+ [unix] Use -fvisibility=hidden.
+
+ It is now widely recommended that ELF shared libraries hide symbols
+ except those with explicit __attribute__((visibility("default"))).
+ This is supported by all major compilers and should rather be an
+ option in libtool.
+
+ * builds/unix/configure.raw: Add -fvisibility=hidden to CFLAGS.
+ * builds/unix/ftconfig.in, builds/vms/ftconfig.h,
+ include/freetype/config/ftconfig.h (FT_EXPORT): Use visibility
+ attribute.
+
2018-01-27 Werner Lemberg <wl@gnu.org>
[truetype] Better protection against invalid VF data.
--- a/builds/unix/configure.raw
+++ b/builds/unix/configure.raw
@@ -299,6 +299,18 @@
AC_SUBST([XX_ANSIFLAGS])
+# It is recommended that shared libraries hide symbols except those with
+# explicit __attribute__((visibility("default"))).
+#
+AC_MSG_CHECKING([for -fvisibility=hidden compiler flag])
+orig_CFLAGS="${CFLAGS}"
+CFLAGS="${CFLAGS} -fvisibility=hidden"
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([],[])],
+ AC_MSG_RESULT(yes),
+ CFLAGS="${orig_CFLAGS}"
+ AC_MSG_RESULT(no))
+
+
# All library tests below try `pkg-config' first. If that fails, a function
# from the library is tested in the traditional autoconf way (zlib, bzip2),
# or a config script is called (libpng).
--- a/builds/unix/ftconfig.in
+++ b/builds/unix/ftconfig.in
@@ -454,9 +454,9 @@
#endif /* !FT_BASE_DEF */
- /* When compiling FreeType as a DLL, some systems/compilers need a */
- /* special attribute in front OR after the return type of function */
- /* declarations. */
+ /* When compiling FreeType as a DLL or DSO with hidden visibility */
+ /* some systems/compilers need a special attribute in front OR after */
+ /* the return type of function declarations. */
/* */
/* Two macros are used within the FreeType source code to define */
/* exported library functions: FT_EXPORT and FT_EXPORT_DEF. */
@@ -487,21 +487,28 @@
/* */
#ifndef FT_EXPORT
-#ifdef __cplusplus
+#ifdef FT2_BUILD_LIBRARY
+
+#if defined( _WIN32 ) && ( defined( _DLL ) || defined( DLL_EXPORT ) )
+#define FT_EXPORT( x ) __declspec( dllexport ) x
+#elif defined( __GNUC__ ) && __GNUC__ >= 4
+#define FT_EXPORT( x ) __attribute__(( visibility( "default" ) )) x
+#elif defined( __cplusplus )
#define FT_EXPORT( x ) extern "C" x
#else
#define FT_EXPORT( x ) extern x
#endif
-#ifdef _WIN32
-#if defined( FT2_BUILD_LIBRARY ) && \
- ( defined( _DLL ) || defined( DLL_EXPORT ) )
-#undef FT_EXPORT
-#define FT_EXPORT( x ) __declspec( dllexport ) x
-#elif defined( FT2_DLLIMPORT )
-#undef FT_EXPORT
+#else
+
+#if defined( FT2_DLLIMPORT )
#define FT_EXPORT( x ) __declspec( dllimport ) x
+#elif defined( __cplusplus )
+#define FT_EXPORT( x ) extern "C" x
+#else
+#define FT_EXPORT( x ) extern x
#endif
+
#endif
#endif /* !FT_EXPORT */
--- a/builds/vms/ftconfig.h
+++ b/builds/vms/ftconfig.h
@@ -406,9 +406,9 @@
#endif /* !FT_BASE_DEF */
- /* When compiling FreeType as a DLL, some systems/compilers need a */
- /* special attribute in front OR after the return type of function */
- /* declarations. */
+ /* When compiling FreeType as a DLL or DSO with hidden visibility */
+ /* some systems/compilers need a special attribute in front OR after */
+ /* the return type of function declarations. */
/* */
/* Two macros are used within the FreeType source code to define */
/* exported library functions: FT_EXPORT and FT_EXPORT_DEF. */
@@ -439,21 +439,28 @@
/* */
#ifndef FT_EXPORT
-#ifdef __cplusplus
+#ifdef FT2_BUILD_LIBRARY
+
+#if defined( _WIN32 ) && ( defined( _DLL ) || defined( DLL_EXPORT ) )
+#define FT_EXPORT( x ) __declspec( dllexport ) x
+#elif defined( __GNUC__ ) && __GNUC__ >= 4
+#define FT_EXPORT( x ) __attribute__(( visibility( "default" ) )) x
+#elif defined( __cplusplus )
#define FT_EXPORT( x ) extern "C" x
#else
#define FT_EXPORT( x ) extern x
#endif
-#ifdef _WIN32
-#if defined( FT2_BUILD_LIBRARY ) && \
- ( defined( _DLL ) || defined( DLL_EXPORT ) )
-#undef FT_EXPORT
-#define FT_EXPORT( x ) __declspec( dllexport ) x
-#elif defined( FT2_DLLIMPORT )
-#undef FT_EXPORT
+#else
+
+#if defined( FT2_DLLIMPORT )
#define FT_EXPORT( x ) __declspec( dllimport ) x
+#elif defined( __cplusplus )
+#define FT_EXPORT( x ) extern "C" x
+#else
+#define FT_EXPORT( x ) extern x
#endif
+
#endif
#endif /* !FT_EXPORT */
--- a/include/freetype/config/ftconfig.h
+++ b/include/freetype/config/ftconfig.h
@@ -422,9 +422,9 @@
#endif /* !FT_BASE_DEF */
- /* When compiling FreeType as a DLL, some systems/compilers need a */
- /* special attribute in front OR after the return type of function */
- /* declarations. */
+ /* When compiling FreeType as a DLL or DSO with hidden visibility */
+ /* some systems/compilers need a special attribute in front OR after */
+ /* the return type of function declarations. */
/* */
/* Two macros are used within the FreeType source code to define */
/* exported library functions: FT_EXPORT and FT_EXPORT_DEF. */
@@ -455,21 +455,28 @@
/* */
#ifndef FT_EXPORT
-#ifdef __cplusplus
+#ifdef FT2_BUILD_LIBRARY
+
+#if defined( _WIN32 ) && ( defined( _DLL ) || defined( DLL_EXPORT ) )
+#define FT_EXPORT( x ) __declspec( dllexport ) x
+#elif defined( __GNUC__ ) && __GNUC__ >= 4
+#define FT_EXPORT( x ) __attribute__(( visibility( "default" ) )) x
+#elif defined( __cplusplus )
#define FT_EXPORT( x ) extern "C" x
#else
#define FT_EXPORT( x ) extern x
#endif
-#ifdef _WIN32
-#if defined( FT2_BUILD_LIBRARY ) && \
- ( defined( _DLL ) || defined( DLL_EXPORT ) )
-#undef FT_EXPORT
-#define FT_EXPORT( x ) __declspec( dllexport ) x
-#elif defined( FT2_DLLIMPORT )
-#undef FT_EXPORT
+#else
+
+#if defined( FT2_DLLIMPORT )
#define FT_EXPORT( x ) __declspec( dllimport ) x
+#elif defined( __cplusplus )
+#define FT_EXPORT( x ) extern "C" x
+#else
+#define FT_EXPORT( x ) extern x
#endif
+
#endif
#endif /* !FT_EXPORT */
--
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