Ensure extension is linked with -Wl,-z,nodelete

See: #43.

Author: kleisauke

.gitattributes

@@ -0,0 +1 @@
+m4/** linguist-generated=true linguist-vendored=true

config.m4

@@ -1,6 +1,11 @@
 dnl $Id$
 dnl config.m4 for extension vips
 
+m4_include(m4/ax_require_defined.m4)
+m4_include(m4/ax_append_flag.m4)
+m4_include(m4/ax_check_link_flag.m4)
+m4_include(m4/ax_append_link_flags.m4)
+
 PHP_ARG_WITH(vips, for vips support,
 [  --with-vips             Include vips support])
 
@@ -35,6 +40,10 @@ if test x"$PHP_VIPS" != x"no"; then
   ],[$VIPS_LIBS]
   )
 
+  # Mark DSO non-deletable at runtime.
+  # See: https://github.com/libvips/php-vips-ext/issues/43
+  AX_APPEND_LINK_FLAGS([-Wl,-z,nodelete])
+
   AC_DEFINE(HAVE_VIPS, 1, [Whether you have vips])
   PHP_NEW_EXTENSION(vips, vips.c, $ext_shared,, -DZEND_ENABLE_STATIC_TSRMLS_CACHE=1 $VIPS_CFLAGS)
   PHP_SUBST(VIPS_SHARED_LIBADD)

m4/ax_append_flag.m4

@@ -42,6 +42,13 @@ http://pear.php.net/dtd/package-2.0.xsd">
    <file role='src' name='php_vips.h'/>
    <file role='src' name='vips.c'/>
 
+   <dir name="m4">
+    <file role='src' name='ax_append_flag.m4'/>
+    <file role='src' name='ax_append_link_flags.m4'/>
+    <file role='src' name='ax_check_link_flag.m4'/>
+    <file role='src' name='ax_require_defined.m4'/>
+   </dir>
+
    <dir name="tests">
     <file role='test' name='001.phpt'/>
     <file role='test' name='002.phpt'/>

m4/ax_append_link_flags.m4

@@ -13,7 +13,6 @@
 #include "php.h"
 #include "php_ini.h"
 #include "ext/standard/info.h"
-#include "SAPI.h"
 #include "php_vips.h"
 
 #include <vips/vips.h>
@@ -2007,41 +2006,6 @@ static void php_free_gobject(zend_resource *rsrc)
  */
 PHP_MINIT_FUNCTION(vips)
 {
-	if (strcmp(sapi_module.name, "apache2handler") == 0) {
-		/* "apachectl graceful" can cause us terrible problems. What happens:
-		 *
-		 * - the main apache process unloads this extension, vips.so
-		 * - in turn, the C runtime will unload libvips.so, the vips library,
-		 *   since vips.so is the only thing that references it
-		 * - libvips.so in turn uses glib.so, but this is often not unloaded,
-		 *   since other parts of apache can be using it (glib could also
-		 *   possibly be preventing unload itself, I'm not sure)
-		 * - the main apache process then reloads vips.so, which in turn will
-		 *   reload libvips.so as it starts up
-		 * - vips.so tries to init libvips.so
-		 * - libvips.so tries to register its types (such as VipsImage) with
-		 *   glib.so, but finds the types from the previous init still there
-		 * - everything breaks
-		 *
-		 * A simple fix that will always work is just to lock libvips in 
-		 * memory and prevent unload. We intentionally leak refs to the shared
-		 * library. 
-		 *
-		 * We include the binary API version number that this extension needs. 
-		 * We can't just load .so, that's only installed with libvips-dev, 
-		 * which may not be present at runtime.
-		 */
-#ifdef VIPS_SONAME
-		if (!dlopen(VIPS_SONAME, RTLD_LAZY | RTLD_NODELETE)) 
-#else /*!VIPS_SONAME*/
-		if (!dlopen("libvips.so.42", RTLD_LAZY | RTLD_NODELETE)) 
-#endif /*VIPS_SONAME*/
-		{
-			sapi_module.sapi_error(E_WARNING, "php-vips-ext: unable to lock "
-				"libvips -- graceful may be unreliable");
-		}
-	}
-
 	/* If you have INI entries, uncomment these lines
 	REGISTER_INI_ENTRIES();
 	*/