[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.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207
diff --git a/ChangeLog b/ChangeLog
index 0708e5e..71fd567 100644
--- 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.
diff --git a/builds/unix/configure.raw b/builds/unix/configure.raw
index d76c324..3d17583 100644
--- a/builds/unix/configure.raw
+++ b/builds/unix/configure.raw
@@ -299,6 +299,18 @@ AC_SUBST([XX_CFLAGS])
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).
diff --git a/builds/unix/ftconfig.in b/builds/unix/ftconfig.in
index ca90588..b9c21da 100644
--- a/builds/unix/ftconfig.in
+++ b/builds/unix/ftconfig.in
@@ -454,9 +454,9 @@ FT_BEGIN_HEADER
#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 @@ FT_BEGIN_HEADER
/* */
#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 */
diff --git a/builds/vms/ftconfig.h b/builds/vms/ftconfig.h
index d87ea69..021e2c6 100644
--- a/builds/vms/ftconfig.h
+++ b/builds/vms/ftconfig.h
@@ -406,9 +406,9 @@ FT_BEGIN_HEADER
#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 @@ FT_BEGIN_HEADER
/* */
#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 */
diff --git a/include/freetype/config/ftconfig.h b/include/freetype/config/ftconfig.h
index 8ff143e..eedebf4 100644
--- a/include/freetype/config/ftconfig.h
+++ b/include/freetype/config/ftconfig.h
@@ -422,9 +422,9 @@ FT_BEGIN_HEADER
#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 @@ FT_BEGIN_HEADER
/* */
#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 */