Merge branch 'yugr-issue195' (#197, fixes #195)

expat/CMakeLists.txt

@@ -101,6 +101,10 @@ set(EXTRA_COMPILE_FLAGS)
 if(FLAG_NO_STRICT_ALIASING)
     set(EXTRA_COMPILE_FLAGS "${EXTRA_COMPILE_FLAGS} -fno-strict-aliasing")
 endif()
+if(FLAG_VISIBILITY)
+  add_definitions(-DXML_ENABLE_VISIBILITY=1)
+  set(EXTRA_COMPILE_FLAGS "${EXTRA_COMPILE_FLAGS} -fvisibility=hidden")
+endif(FLAG_VISIBILITY)
 if (WARNINGS_AS_ERRORS)
     if(MSVC)
         add_definitions(/WX)

expat/Changes

@@ -4,10 +4,13 @@ NOTE: We are looking for help with a few things:
 
 Release x.x.x XXX XXXXXX XX XXXX
         Other changes:
+       #195 #197  Autotools/CMake: Utilize -fvisibility=hidden to stop
+                    exporting non-API symbols
             #212  CMake: Make libdir of pkgconfig expat.pc support multilib
 
         Special thanks to:
             @userwithuid
+            Yury Gribov
 
 Release 2.2.6 Sun August 12 2018
         Bug fixes:

expat/ConfigureChecks.cmake

@@ -68,3 +68,4 @@ configure_file(expat_config.h.cmake "${CMAKE_CURRENT_BINARY_DIR}/expat_config.h"
 add_definitions(-DHAVE_EXPAT_CONFIG_H)
 
 check_c_compiler_flag("-fno-strict-aliasing" FLAG_NO_STRICT_ALIASING)
+check_c_compiler_flag("-fvisibility=hidden" FLAG_VISIBILITY)

expat/configure.ac

@@ -88,6 +88,13 @@ if test "$GCC" = yes ; then
     LDFLAGS="${LDFLAGS} -fno-strict-aliasing"
 fi
 
+AC_MSG_CHECKING(whether compiler supports visibility)
+OLDCFLAGS="$CFLAGS"
+CFLAGS="$CFLAGS -fvisibility=hidden -Wall -Werror"
+AC_COMPILE_IFELSE([AC_LANG_SOURCE([[void __attribute__((visibility("default"))) foo(void); void foo(void) {}]])],
+                  AC_MSG_RESULT(yes); CFLAGS="$OLDCFLAGS -fvisibility=hidden -DXML_ENABLE_VISIBILITY=1",
+                  AC_MSG_RESULT(no); CFLAGS="$OLDCFLAGS")
+
 dnl Checks for header files.
 AC_HEADER_STDC
 

expat/lib/expat_external.h

@@ -93,7 +93,11 @@
 # endif
 #endif  /* not defined XML_STATIC */
 
-#if !defined(XMLIMPORT) && defined(__GNUC__) && (__GNUC__ >= 4)
+#ifndef XML_ENABLE_VISIBILITY
+# define XML_ENABLE_VISIBILITY 0
+#endif
+
+#if !defined(XMLIMPORT) && XML_ENABLE_VISIBILITY
 # define XMLIMPORT __attribute__ ((visibility ("default")))
 #endif
 

expat/lib/internal.h

@@ -115,6 +115,11 @@ extern "C" {
 #endif
 
 
+#ifdef XML_ENABLE_VISIBILITY
+#if XML_ENABLE_VISIBILITY
+__attribute__ ((visibility ("default")))
+#endif
+#endif
 void
 _INTERNAL_trim_to_complete_utf8_characters(const char * from, const char ** fromLimRef);