path: root/vips-pr44.patch

From f08dc82d066b600cff73720cd040e5d7d50c36eb Mon Sep 17 00:00:00 2001
From: Kleis Auke Wolthuizen <github@kleisauke.nl>
Date: Mon, 6 Sep 2021 10:57:56 +0200
Subject: [PATCH] Ensure extension is linked with -Wl,-z,nodelete

See: https://github.com/libvips/php-vips-ext/issues/43.
---
 .gitattributes             |  1 +
 config.m4                  |  9 +++++++
 m4/ax_append_flag.m4       | 50 +++++++++++++++++++++++++++++++++++
 m4/ax_append_link_flags.m4 | 44 +++++++++++++++++++++++++++++++
 m4/ax_check_link_flag.m4   | 53 ++++++++++++++++++++++++++++++++++++++
 m4/ax_require_defined.m4   | 37 ++++++++++++++++++++++++++
 package.xml                |  7 +++++
 vips.c                     | 36 --------------------------
 8 files changed, 201 insertions(+), 36 deletions(-)
 create mode 100644 .gitattributes
 create mode 100644 m4/ax_append_flag.m4
 create mode 100644 m4/ax_append_link_flags.m4
 create mode 100644 m4/ax_check_link_flag.m4
 create mode 100644 m4/ax_require_defined.m4

diff --git a/config.m4 b/config.m4
index 729cc25..b72931e 100644
--- a/config.m4
+++ b/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)
diff --git a/m4/ax_append_flag.m4 b/m4/ax_append_flag.m4
new file mode 100644
index 0000000..dd6d8b6
--- /dev/null
+++ b/m4/ax_append_flag.m4
@@ -0,0 +1,50 @@
+# ===========================================================================
+#      https://www.gnu.org/software/autoconf-archive/ax_append_flag.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_APPEND_FLAG(FLAG, [FLAGS-VARIABLE])
+#
+# DESCRIPTION
+#
+#   FLAG is appended to the FLAGS-VARIABLE shell variable, with a space
+#   added in between.
+#
+#   If FLAGS-VARIABLE is not specified, the current language's flags (e.g.
+#   CFLAGS) is used.  FLAGS-VARIABLE is not changed if it already contains
+#   FLAG.  If FLAGS-VARIABLE is unset in the shell, it is set to exactly
+#   FLAG.
+#
+#   NOTE: Implementation based on AX_CFLAGS_GCC_OPTION.
+#
+# LICENSE
+#
+#   Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
+#   Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
+#
+#   Copying and distribution of this file, with or without modification, are
+#   permitted in any medium without royalty provided the copyright notice
+#   and this notice are preserved.  This file is offered as-is, without any
+#   warranty.
+
+#serial 8
+
+AC_DEFUN([AX_APPEND_FLAG],
+[dnl
+AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_SET_IF
+AS_VAR_PUSHDEF([FLAGS], [m4_default($2,_AC_LANG_PREFIX[FLAGS])])
+AS_VAR_SET_IF(FLAGS,[
+  AS_CASE([" AS_VAR_GET(FLAGS) "],
+    [*" $1 "*], [AC_RUN_LOG([: FLAGS already contains $1])],
+    [
+     AS_VAR_APPEND(FLAGS,[" $1"])
+     AC_RUN_LOG([: FLAGS="$FLAGS"])
+    ])
+  ],
+  [
+  AS_VAR_SET(FLAGS,[$1])
+  AC_RUN_LOG([: FLAGS="$FLAGS"])
+  ])
+AS_VAR_POPDEF([FLAGS])dnl
+])dnl AX_APPEND_FLAG
diff --git a/m4/ax_append_link_flags.m4 b/m4/ax_append_link_flags.m4
new file mode 100644
index 0000000..99b9fa5
--- /dev/null
+++ b/m4/ax_append_link_flags.m4
@@ -0,0 +1,44 @@
+# ===========================================================================
+#   https://www.gnu.org/software/autoconf-archive/ax_append_link_flags.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_APPEND_LINK_FLAGS([FLAG1 FLAG2 ...], [FLAGS-VARIABLE], [EXTRA-FLAGS], [INPUT])
+#
+# DESCRIPTION
+#
+#   For every FLAG1, FLAG2 it is checked whether the linker works with the
+#   flag.  If it does, the flag is added FLAGS-VARIABLE
+#
+#   If FLAGS-VARIABLE is not specified, the linker's flags (LDFLAGS) is
+#   used. During the check the flag is always added to the linker's flags.
+#
+#   If EXTRA-FLAGS is defined, it is added to the linker's default flags
+#   when the check is done.  The check is thus made with the flags: "LDFLAGS
+#   EXTRA-FLAGS FLAG".  This can for example be used to force the linker to
+#   issue an error when a bad flag is given.
+#
+#   INPUT gives an alternative input source to AC_COMPILE_IFELSE.
+#
+#   NOTE: This macro depends on the AX_APPEND_FLAG and AX_CHECK_LINK_FLAG.
+#   Please keep this macro in sync with AX_APPEND_COMPILE_FLAGS.
+#
+# LICENSE
+#
+#   Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
+#
+#   Copying and distribution of this file, with or without modification, are
+#   permitted in any medium without royalty provided the copyright notice
+#   and this notice are preserved.  This file is offered as-is, without any
+#   warranty.
+
+#serial 7
+
+AC_DEFUN([AX_APPEND_LINK_FLAGS],
+[AX_REQUIRE_DEFINED([AX_CHECK_LINK_FLAG])
+AX_REQUIRE_DEFINED([AX_APPEND_FLAG])
+for flag in $1; do
+  AX_CHECK_LINK_FLAG([$flag], [AX_APPEND_FLAG([$flag], [m4_default([$2], [LDFLAGS])])], [], [$3], [$4])
+done
+])dnl AX_APPEND_LINK_FLAGS
diff --git a/m4/ax_check_link_flag.m4 b/m4/ax_check_link_flag.m4
new file mode 100644
index 0000000..03a30ce
--- /dev/null
+++ b/m4/ax_check_link_flag.m4
@@ -0,0 +1,53 @@
+# ===========================================================================
+#    https://www.gnu.org/software/autoconf-archive/ax_check_link_flag.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_CHECK_LINK_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS], [INPUT])
+#
+# DESCRIPTION
+#
+#   Check whether the given FLAG works with the linker or gives an error.
+#   (Warnings, however, are ignored)
+#
+#   ACTION-SUCCESS/ACTION-FAILURE are shell commands to execute on
+#   success/failure.
+#
+#   If EXTRA-FLAGS is defined, it is added to the linker's default flags
+#   when the check is done.  The check is thus made with the flags: "LDFLAGS
+#   EXTRA-FLAGS FLAG".  This can for example be used to force the linker to
+#   issue an error when a bad flag is given.
+#
+#   INPUT gives an alternative input source to AC_LINK_IFELSE.
+#
+#   NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this
+#   macro in sync with AX_CHECK_{PREPROC,COMPILE}_FLAG.
+#
+# LICENSE
+#
+#   Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
+#   Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
+#
+#   Copying and distribution of this file, with or without modification, are
+#   permitted in any medium without royalty provided the copyright notice
+#   and this notice are preserved.  This file is offered as-is, without any
+#   warranty.
+
+#serial 6
+
+AC_DEFUN([AX_CHECK_LINK_FLAG],
+[AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF
+AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_ldflags_$4_$1])dnl
+AC_CACHE_CHECK([whether the linker accepts $1], CACHEVAR, [
+  ax_check_save_flags=$LDFLAGS
+  LDFLAGS="$LDFLAGS $4 $1"
+  AC_LINK_IFELSE([m4_default([$5],[AC_LANG_PROGRAM()])],
+    [AS_VAR_SET(CACHEVAR,[yes])],
+    [AS_VAR_SET(CACHEVAR,[no])])
+  LDFLAGS=$ax_check_save_flags])
+AS_VAR_IF(CACHEVAR,yes,
+  [m4_default([$2], :)],
+  [m4_default([$3], :)])
+AS_VAR_POPDEF([CACHEVAR])dnl
+])dnl AX_CHECK_LINK_FLAGS
diff --git a/m4/ax_require_defined.m4 b/m4/ax_require_defined.m4
new file mode 100644
index 0000000..17c3eab
--- /dev/null
+++ b/m4/ax_require_defined.m4
@@ -0,0 +1,37 @@
+# ===========================================================================
+#    https://www.gnu.org/software/autoconf-archive/ax_require_defined.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_REQUIRE_DEFINED(MACRO)
+#
+# DESCRIPTION
+#
+#   AX_REQUIRE_DEFINED is a simple helper for making sure other macros have
+#   been defined and thus are available for use.  This avoids random issues
+#   where a macro isn't expanded.  Instead the configure script emits a
+#   non-fatal:
+#
+#     ./configure: line 1673: AX_CFLAGS_WARN_ALL: command not found
+#
+#   It's like AC_REQUIRE except it doesn't expand the required macro.
+#
+#   Here's an example:
+#
+#     AX_REQUIRE_DEFINED([AX_CHECK_LINK_FLAG])
+#
+# LICENSE
+#
+#   Copyright (c) 2014 Mike Frysinger <vapier@gentoo.org>
+#
+#   Copying and distribution of this file, with or without modification, are
+#   permitted in any medium without royalty provided the copyright notice
+#   and this notice are preserved. This file is offered as-is, without any
+#   warranty.
+
+#serial 2
+
+AC_DEFUN([AX_REQUIRE_DEFINED], [dnl
+  m4_ifndef([$1], [m4_fatal([macro ]$1[ is not defined; is a m4 file missing?])])
+])dnl AX_REQUIRE_DEFINED
diff --git a/vips.c b/vips.c
index 33b47d4..2e96aad 100644
--- a/vips.c
+++ b/vips.c
@@ -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();
 	*/