linux: unexport as many symbols as possible

See discussion on http://code.google.com/p/chromium/issues/detail?id=17557
On linux, exported symbols from a shared library can be overridden by another unit (e.g. the browser) if it exports the same ones. So compile everything with -fvisibility=hidden to make every symbol private by default, and explicitly export the ones that we care about. Also make sure that third-party deps (e.g. icu) don't explicitly export symbols.

Review URL: http://codereview.chromium.org/160317


git-svn-id: svn://svn.chromium.org/chrome/trunk/src@21992 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 13 insertions, 6 deletions

diff --git a/o3d/plugin/cross/main.cc b/o3d/plugin/cross/main.cc
index d6144ca..da16756 100644
--- a/o3d/plugin/cross/main.cc
+++ b/o3d/plugin/cross/main.cc
@@ -148,7 +148,7 @@ namespace o3d {
 extern "C" {
 #endif
 
-NPError OSCALL NP_GetEntryPoints(NPPluginFuncs *pluginFuncs) {
+NPError EXPORT_SYMBOL OSCALL NP_GetEntryPoints(NPPluginFuncs *pluginFuncs) {
   HANDLE_CRASHES;
   pluginFuncs->version = 11;
   pluginFuncs->size = sizeof(*pluginFuncs);
@@ -169,7 +169,7 @@ NPError OSCALL NP_GetEntryPoints(NPPluginFuncs *pluginFuncs) {
   return NPERR_NO_ERROR;
 }
 
-char *NP_GetMIMEDescription(void) {
+char * EXPORT_SYMBOL NP_GetMIMEDescription(void) {
   return O3D_PLUGIN_MIME_TYPE "::O3D MIME";
 }
 
@@ -177,7 +177,8 @@ char *NP_GetMIMEDescription(void) {
 
 #if !defined(O3D_INTERNAL_PLUGIN)
 extern "C" {
-NPError NP_GetValue(void *instance, NPPVariable variable, void *value) {
+NPError EXPORT_SYMBOL NP_GetValue(void *instance, NPPVariable variable,
+                                  void *value) {
   return o3d::NP_GetValue(instance, variable, value);
 }
 }
diff --git a/o3d/plugin/cross/main.h b/o3d/plugin/cross/main.h
index 29e386a..049c688 100644
--- a/o3d/plugin/cross/main.h
+++ b/o3d/plugin/cross/main.h
@@ -59,6 +59,12 @@
 #define HANDLE_CRASHES void(0)
 #else  // O3D_INTERNAL_PLUGIN
 
+#if defined(OS_LINUX)
+#define EXPORT_SYMBOL __attribute__((visibility ("default")))
+#else
+#define EXPORT_SYMBOL
+#endif
+
 extern ExceptionManager *g_exception_manager;
 
 // BreakpadEnabler is a simple class to keep track of whether or not
diff --git a/o3d/plugin/linux/main_linux.cc b/o3d/plugin/linux/main_linux.cc
index 55096db..b91c9d8 100644
--- a/o3d/plugin/linux/main_linux.cc
+++ b/o3d/plugin/linux/main_linux.cc
@@ -622,15 +622,15 @@ namespace o3d {
 extern "C" {
 #endif
 
-NPError OSCALL NP_Initialize(NPNetscapeFuncs *browserFuncs,
-                             NPPluginFuncs *pluginFuncs) {
+NPError EXPORT_SYMBOL OSCALL NP_Initialize(NPNetscapeFuncs *browserFuncs,
+                                           NPPluginFuncs *pluginFuncs) {
   NPError retval = InitializeNPNApi(browserFuncs);
   if (retval != NPERR_NO_ERROR) return retval;
   NP_GetEntryPoints(pluginFuncs);
   return InitializePlugin();
 }
 
-NPError OSCALL NP_Shutdown(void) {
+NPError EXPORT_SYMBOL OSCALL NP_Shutdown(void) {
   HANDLE_CRASHES;
   DLOG(INFO) << "NP_Shutdown";