Cleanup visibility of API functions

Import visibility_hidden.m4 macro from acl and use it in configure.ac
This will enable -fvisibility CFLAG when supported by compiler.

Mark API functions with default visibility attribute.

6 files changed, 84 insertions, 18 deletions

diff --git a/configure.ac b/configure.ac
index a5f9de5..7260ce3 100644
--- a/configure.ac
+++ b/configure.ac
@@ -29,6 +29,7 @@ AC_USE_SYSTEM_EXTENSIONS
 AC_C_CONST
 AC_TYPE_MODE_T
 AC_FUNC_ALLOCA
+AC_FUNC_GCC_VISIBILITY
 
 AM_PROG_AR
 LT_INIT
diff --git a/include/Makemodule.am b/include/Makemodule.am
index 2ab600a..e4f56f9 100644
--- a/include/Makemodule.am
+++ b/include/Makemodule.am
@@ -1,9 +1,26 @@
-pkginclude_HEADERS += \
+noinst_HEADERS += \
 	include/attributes.h \
 	include/error_context.h \
-	include/libattr.h
-
-noinst_HEADERS += \
+	include/libattr.h \
 	include/misc.h \
 	include/nls.h \
 	include/walk_tree.h
+
+
+SUBST_INSTALL_HEADER = \
+	subst_install_header() { \
+	  file=`echo "$$1" | sed -e 's,^.*/,,'`; \
+	  $(SED) -e "s/\<EXPORT\>/extern/" < "$$1" > "include/$$file.t" || exit 1; \
+	  $(MKDIR_P) "$$2" || exit 1; \
+	  $(INSTALL_HEADER) "include/$$file.t" "$$2/$$file" || exit 1; \
+	  $(RM) "include/$$file.t"; \
+	}; \
+	subst_install_header
+
+install-attributes_h: include/attributes.h
+	$(SUBST_INSTALL_HEADER) "$<" "$(DESTDIR)$(pkgincludedir)"
+install-error_context_h: include/error_context.h
+	$(SUBST_INSTALL_HEADER) "$<" "$(DESTDIR)$(pkgincludedir)"
+install-libattr_h: include/libattr.h
+	$(SUBST_INSTALL_HEADER) "$<" "$(DESTDIR)$(pkgincludedir)"
+install-data-local: install-attributes_h install-error_context_h install-libattr_h
diff --git a/include/attributes.h b/include/attributes.h
index 8b73c5c..14beb8f 100644
--- a/include/attributes.h
+++ b/include/attributes.h
@@ -125,10 +125,10 @@ typedef struct attr_multiop {
  * be set to the actual number of bytes used in the value buffer upon return.
  * The return value is -1 on error (w/errno set appropriately), 0 on success.
  */
-extern int attr_get (const char *__path, const char *__attrname,
+EXPORT int attr_get (const char *__path, const char *__attrname,
 			char *__attrvalue, int *__valuelength, int __flags)
 	__attribute__ ((deprecated ("Use getxattr or lgetxattr instead")));
-extern int attr_getf (int __fd, const char *__attrname, char *__attrvalue,
+EXPORT int attr_getf (int __fd, const char *__attrname, char *__attrvalue,
 			int *__valuelength, int __flags)
 	__attribute__ ((deprecated ("Use fgetxattr instead")));
 
@@ -136,11 +136,11 @@ extern int attr_getf (int __fd, const char *__attrname, char *__attrvalue,
  * Set the value of an attribute, creating the attribute if necessary.
  * The return value is -1 on error (w/errno set appropriately), 0 on success.
  */
-extern int attr_set (const char *__path, const char *__attrname,
+EXPORT int attr_set (const char *__path, const char *__attrname,
 			const char *__attrvalue, const int __valuelength,
 			int __flags)
 	__attribute__ ((deprecated ("Use setxattr or lsetxattr instead")));
-extern int attr_setf (int __fd, const char *__attrname,
+EXPORT int attr_setf (int __fd, const char *__attrname,
 			const char *__attrvalue, const int __valuelength,
 			int __flags)
 	__attribute__ ((deprecated ("Use fsetxattr instead")));
@@ -149,10 +149,10 @@ extern int attr_setf (int __fd, const char *__attrname,
  * Remove an attribute.
  * The return value is -1 on error (w/errno set appropriately), 0 on success.
  */
-extern int attr_remove (const char *__path, const char *__attrname,
+EXPORT int attr_remove (const char *__path, const char *__attrname,
 			int __flags)
 	__attribute__ ((deprecated ("Use removexattr or lremovexattr instead")));
-extern int attr_removef (int __fd, const char *__attrname, int __flags)
+EXPORT int attr_removef (int __fd, const char *__attrname, int __flags)
 	__attribute__ ((deprecated ("Use fremovexattr instead")));
 
 /*
@@ -162,10 +162,10 @@ extern int attr_removef (int __fd, const char *__attrname, int __flags)
  * fit into the buffer on the first system call.
  * The return value is -1 on error (w/errno set appropriately), 0 on success.
  */
-int attr_list(const char *__path, char *__buffer, const int __buffersize,
+EXPORT int attr_list(const char *__path, char *__buffer, const int __buffersize,
 		int __flags, attrlist_cursor_t *__cursor)
 	__attribute__ ((deprecated ("Use listxattr or llistxattr instead")));
-int attr_listf(int __fd, char *__buffer, const int __buffersize,
+EXPORT int attr_listf(int __fd, char *__buffer, const int __buffersize,
 		int __flags, attrlist_cursor_t *__cursor)
 	__attribute__ ((deprecated ("Use flistxattr instead")));
 
@@ -186,10 +186,10 @@ int attr_listf(int __fd, char *__buffer, const int __buffersize,
  * the corresponding "simple" attribute interface.  For example: the args
  * to a ATTR_OP_GET are the same as the args to an attr_get() call.
  */
-extern int attr_multi (const char *__path, attr_multiop_t *__oplist,
+EXPORT int attr_multi (const char *__path, attr_multiop_t *__oplist,
 			int __count, int __flags)
 	__attribute__ ((deprecated ("Use getxattr, setxattr, listxattr, removexattr instead")));
-extern int attr_multif (int __fd, attr_multiop_t *__oplist,
+EXPORT int attr_multif (int __fd, attr_multiop_t *__oplist,
 			int __count, int __flags)
 	__attribute__ ((deprecated ("Use getxattr, setxattr, listxattr, removexattr instead")));
 
diff --git a/include/libattr.h b/include/libattr.h
index 81ebc1b..472dca4 100644
--- a/include/libattr.h
+++ b/include/libattr.h
@@ -24,20 +24,20 @@ extern "C" {
 
 struct error_context;
 
-extern int attr_copy_file (const char *, const char *,
+EXPORT int attr_copy_file (const char *, const char *,
 			   int (*) (const char *, struct error_context *),
 			   struct error_context *);
-extern int attr_copy_fd (const char *, int, const char *, int,
+EXPORT int attr_copy_fd (const char *, int, const char *, int,
 			 int (*) (const char *, struct error_context *),
 			 struct error_context *);
 
 /* Keep this function for backwards compatibility. */
-extern int attr_copy_check_permissions(const char *, struct error_context *);
+EXPORT int attr_copy_check_permissions(const char *, struct error_context *);
 
 #define ATTR_ACTION_SKIP	1
 #define ATTR_ACTION_PERMISSIONS	2
 
-extern int attr_copy_action(const char *, struct error_context *);
+EXPORT int attr_copy_action(const char *, struct error_context *);
 
 #ifdef __cplusplus
 }
diff --git a/libattr/syscalls.c b/libattr/syscalls.c
index 352841b..3013aa0 100644
--- a/libattr/syscalls.c
+++ b/libattr/syscalls.c
@@ -24,6 +24,10 @@
 
 #include <sys/xattr.h>
 
+#ifdef HAVE_VISIBILITY_ATTRIBUTE
+# pragma GCC visibility push(default)
+#endif
+
 int libattr_setxattr(const char *path, const char *name,
 		     void *value, size_t size, int flags)
 {
@@ -89,3 +93,7 @@ int libattr_fremovexattr(int filedes, const char *name)
 {
 	return fremovexattr(filedes, name);
 }
+
+#ifdef HAVE_VISIBILITY_ATTRIBUTE
+# pragma GCC visibility pop
+#endif
diff --git a/m4/visibility_hidden.m4 b/m4/visibility_hidden.m4
new file mode 100644
index 0000000..dbd57d4
--- /dev/null
+++ b/m4/visibility_hidden.m4
@@ -0,0 +1,40 @@
+dnl Copyright (C) 2003, 2008  Silicon Graphics, Inc.
+dnl
+dnl This program is free software: you can redistribute it and/or modify it
+dnl under the terms of the GNU General Public License as published by
+dnl the Free Software Foundation, either version 2 of the License, or
+dnl (at your option) any later version.
+dnl
+dnl This program is distributed in the hope that it will be useful,
+dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
+dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+dnl GNU General Public License for more details.
+dnl
+dnl You should have received a copy of the GNU General Public License
+dnl along with this program.  If not, see <http://www.gnu.org/licenses/>.
+AC_DEFUN([AC_FUNC_GCC_VISIBILITY],
+  [AC_CACHE_CHECK(whether __attribute__((visibility())) is supported,
+		  libc_cv_visibility_attribute,
+		  [cat > conftest.c <<EOF
+		   int foo __attribute__ ((visibility ("hidden"))) = 1;
+		   int bar __attribute__ ((visibility ("protected"))) = 1;
+EOF
+		  libc_cv_visibility_attribute=no
+		  if ${CC-cc} -Werror -S conftest.c -o conftest.s \
+			>/dev/null 2>&1; then
+		    if grep '\.hidden.*foo' conftest.s >/dev/null; then
+		      if grep '\.protected.*bar' conftest.s >/dev/null; then
+			libc_cv_visibility_attribute=yes
+		      fi
+		    fi
+		  fi
+		  rm -f conftest.[cs]
+		  ])
+   if test $libc_cv_visibility_attribute = yes; then
+     AC_DEFINE(HAVE_VISIBILITY_ATTRIBUTE, [], [GCC supports visibility attributes])
+     AC_DEFINE(EXPORT, [__attribute__ ((visibility ("default"))) extern], [Visibility attribute for API symbols])
+     CFLAGS="${CFLAGS} -fvisibility=hidden"
+   else
+     AC_DEFINE(EXPORT, [extern], [Visibility attribute for API symbols])
+   fi
+  ])