visibility: Use a separate CFLAGS variable

We only want to control the default visibility for our five main
installable libraries: libglib, libgthread, libgmodule, libgobject,
libgio.  We should therefore only set -fvisibility=hidden when building
those.

Use a separate substitution variable for this purpose.

Using CFLAGS directly leads to some modules built in testcases not
exporting their symbols (and then the tests fail).  It also affects the
fam file monitoring module.

Colin had originally done it this way in his visibility patch series but
I failed to understand why so I didn't copy it.  Now I do.

Also: revert changes made to two testcases in an attempt to work around
this issue.

https://bugzilla.gnome.org/show_bug.cgi?id=691756

configure.ac

@@ -3570,6 +3570,7 @@ dnl
 dnl Check for -fvisibility=hidden to determine if we can do GNU-style
 dnl visibility attributes for symbol export control
 dnl
+GLIB_HIDDEN_VISIBILITY_CFLAGS=""
 case "$host" in
   *-*-mingw*)
     dnl on mingw32 we do -fvisibility=hidden and __declspec(dllexport)
@@ -3592,10 +3593,11 @@ case "$host" in
     AS_IF([test "${enable_fvisibility_hidden}" = "yes"], [
       AC_DEFINE([_GLIB_EXTERN], [__attribute__((visibility("default"))) extern],
                 [defines how to decorate public symbols while building])
-      CFLAGS="${CFLAGS} -fvisibility=hidden"
+      GLIB_HIDDEN_VISIBILITY_CFLAGS="-fvisibility=hidden"
     ])
     ;;
 esac
+AC_SUBST(GLIB_HIDDEN_VISIBILITY_CFLAGS)
 
 dnl Compiler flags; macro originates from systemd
 dnl See https://bugzilla.gnome.org/show_bug.cgi?id=608953

gio/Makefile.am

@@ -501,6 +501,7 @@ install-data-local: install-ms-lib
 
 uninstall-local: uninstall-ms-lib
 
+libgio_2_0_la_CFLAGS = $(AM_CFLAGS) $(GLIB_HIDDEN_VISIBILITY_CFLAGS)
 libgio_2_0_la_LDFLAGS = $(GLIB_LINK_FLAGS) \
 	$(gio_win32_res_ldflag) \
 	-version-info $(LT_CURRENT):$(LT_REVISION):$(LT_AGE) \
@@ -508,7 +509,7 @@ libgio_2_0_la_LDFLAGS = $(GLIB_LINK_FLAGS) \
 
 if OS_COCOA
 # This is dumb.  The ObjC source file should be properly named .m
-libgio_2_0_la_CFLAGS = -xobjective-c
+libgio_2_0_la_CFLAGS += -xobjective-c
 libgio_2_0_la_LDFLAGS += -Wl,-framework,Foundation
 endif
 

gio/tests/resourceplugin.c

@@ -1,18 +1,16 @@
-#include "config.h"
-
 #include <gio/gio.h>
 
-_GLIB_EXTERN void
+void
 g_io_module_load (GIOModule *module)
 {
 }
 
-_GLIB_EXTERN void
+void
 g_io_module_unload (GIOModule   *module)
 {
 }
 
-_GLIB_EXTERN char **
+char **
 g_io_module_query (void)
 {
   return NULL;

glib/Makefile.am

@@ -360,6 +360,7 @@ pcre_lib = pcre/libpcre.la
 pcre_inc =
 endif
 
+libglib_2_0_la_CFLAGS = $(AM_CFLAGS) $(GLIB_HIDDEN_VISIBILITY_CFLAGS)
 libglib_2_0_la_LIBADD = libcharset/libcharset.la $(printf_la) @GIO@ @GSPAWN@ @PLATFORMDEP@ @ICONV_LIBS@ @G_LIBS_EXTRA@ $(pcre_lib) $(G_THREAD_LIBS_EXTRA) $(G_THREAD_LIBS_FOR_GTHREAD)
 libglib_2_0_la_DEPENDENCIES = libcharset/libcharset.la $(printf_la) @GIO@ @GSPAWN@ @PLATFORMDEP@ $(glib_win32_res) $(glib_def)
 

gmodule/Makefile.am

@@ -62,6 +62,7 @@ gmodule_win32_res = gmodule-win32-res.o
 gmodule_win32_res_ldflag = -Wl,$(gmodule_win32_res)
 endif
 
+libgmodule_2_0_la_CFLAGS = $(AM_CFLAGS) $(GLIB_HIDDEN_VISIBILITY_CFLAGS)
 libgmodule_2_0_la_SOURCES = gmodule.c
 libgmodule_2_0_la_LDFLAGS = $(GLIB_LINK_FLAGS) \
 	$(gmodule_win32_res_ldflag) \

gobject/Makefile.am

@@ -62,7 +62,7 @@ libgobject_2_0_la_LDFLAGS = $(GLIB_LINK_FLAGS) \
   -version-info $(LT_CURRENT):$(LT_REVISION):$(LT_AGE) \
   -export-dynamic $(no_undefined) $(export_symbols)
 
-libgobject_2_0_la_CFLAGS = $(LIBFFI_CFLAGS)
+libgobject_2_0_la_CFLAGS = $(AM_CFLAGS) $(LIBFFI_CFLAGS) $(GLIB_HIDDEN_VISIBILITY_CFLAGS)
 
 libgobject_2_0_la_LIBADD = $(libglib) $(LIBFFI_LIBS)
 

gthread/Makefile.am

@@ -60,6 +60,7 @@ gthread_win32_res = gthread-win32-res.o
 gthread_win32_res_ldflag = -Wl,$(gthread_win32_res)
 endif
 
+libgthread_2_0_la_CFLAGS = $(AM_CFLAGS) $(GLIB_HIDDEN_VISIBILITY_CFLAGS)
 libgthread_2_0_la_SOURCES = gthread-impl.c
 libgthread_2_0_la_LDFLAGS = $(GLIB_LINK_FLAGS) \
 	$(gthread_win32_res_ldflag) \

tests/libmoduletestplugin_a.c

@@ -27,9 +27,6 @@
 #undef G_DISABLE_ASSERT
 #undef G_LOG_DOMAIN
 
-#include "config.h"
-
-#include <glib.h>
 #include	<gmodule.h>
 #include	<stdlib.h>
 
@@ -39,34 +36,33 @@ void g_clash_func (void);
 void gplugin_say_boo_func (void);
 void gplugin_a_module_func (GModule *module);
 
-_GLIB_EXTERN gchar* gplugin_a_state;
+G_MODULE_EXPORT gchar* gplugin_a_state;
-gchar* gplugin_a_state;
 
-_GLIB_EXTERN void
+G_MODULE_EXPORT void
 gplugin_a_func (void)
 {
   gplugin_a_state = "Hello world";
 }
 
-_GLIB_EXTERN void
+G_MODULE_EXPORT void
 gplugin_clash_func (void)
 {
   gplugin_a_state = "plugin clash";
 }
 
-_GLIB_EXTERN void
+G_MODULE_EXPORT void
 g_clash_func (void)
 {
   gplugin_a_state = "global clash";
 }
 
-_GLIB_EXTERN void
+G_MODULE_EXPORT void
 gplugin_say_boo_func (void)
 {
   gplugin_a_state = "BOOH";
 }
 
-_GLIB_EXTERN void
+G_MODULE_EXPORT void
 gplugin_a_module_func (GModule *module)
 {
   void *f = NULL;

tests/libmoduletestplugin_b.c

@@ -27,12 +27,9 @@
 #undef G_DISABLE_ASSERT
 #undef G_LOG_DOMAIN
 
-#include "config.h"
-
 #include        <gmodule.h>
 
-_GLIB_EXTERN gchar* gplugin_b_state;
+G_MODULE_EXPORT gchar* gplugin_b_state;
-gchar* gplugin_b_state;
 
 const gchar* g_module_check_init (GModule *module);
 void   g_module_unload (GModule *module);
@@ -42,7 +39,7 @@ void gplugin_clash_func (void);
 void g_clash_func (void);
 void gplugin_say_boo_func (void);
 
-_GLIB_EXTERN const gchar*
+G_MODULE_EXPORT const gchar*
 g_module_check_init (GModule *module)
 {
   gplugin_b_state = "check-init";
@@ -50,31 +47,31 @@ g_module_check_init (GModule *module)
   return NULL;
 }
 
-_GLIB_EXTERN void
+G_MODULE_EXPORT void
 g_module_unload (GModule *module)
 {
   gplugin_b_state = "unloaded";
 }
 
-_GLIB_EXTERN void
+G_MODULE_EXPORT void
 gplugin_b_func (void)
 {
   gplugin_b_state = "Hello world";
 }
 
-_GLIB_EXTERN void
+G_MODULE_EXPORT void
 gplugin_clash_func (void)
 {
   gplugin_b_state = "plugin clash";
 }
 
-_GLIB_EXTERN void
+G_MODULE_EXPORT void
 g_clash_func (void)
 {
   gplugin_b_state = "global clash";
 }
 
-_GLIB_EXTERN void
+G_MODULE_EXPORT void
 gplugin_say_boo_func (void)
 {
   gplugin_b_state = "BOOH";

tests/module-test.c

@@ -27,16 +27,14 @@
 #undef G_DISABLE_ASSERT
 #undef G_LOG_DOMAIN
 
-#include "config.h"
-
 #include <gmodule.h>
 #include <string.h>
 
 gchar* global_state;
 
-_GLIB_EXTERN void g_clash_func (void);
+G_MODULE_EXPORT void g_clash_func (void);
 
-_GLIB_EXTERN void
+G_MODULE_EXPORT void
 g_clash_func (void)
 {
   global_state = "global clash";