libmalcontent: Add a constructor to bind the translation domain

This ensures that the translation domain is loaded for malcontent as
soon as the library is loaded.

The same is not needed for libmalcontent-ui, because it always causes
libmalcontent to be loaded.

Signed-off-by: Philip Withnall <withnall@endlessm.com>

libmalcontent/gconstructor.h

@@ -0,0 +1,122 @@
+/*
+  If G_HAS_CONSTRUCTORS is true then the compiler support *both* constructors and
+  destructors, in a sane way, including e.g. on library unload. If not you're on
+  your own.
+
+  Some compilers need #pragma to handle this, which does not work with macros,
+  so the way you need to use this is (for constructors):
+
+  #ifdef G_DEFINE_CONSTRUCTOR_NEEDS_PRAGMA
+  #pragma G_DEFINE_CONSTRUCTOR_PRAGMA_ARGS(my_constructor)
+  #endif
+  G_DEFINE_CONSTRUCTOR(my_constructor)
+  static void my_constructor(void) {
+   ...
+  }
+
+*/
+
+#ifndef __GTK_DOC_IGNORE__
+
+#if  __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 7)
+
+#define G_HAS_CONSTRUCTORS 1
+
+#define G_DEFINE_CONSTRUCTOR(_func) static void __attribute__((constructor)) _func (void);
+#define G_DEFINE_DESTRUCTOR(_func) static void __attribute__((destructor)) _func (void);
+
+#elif defined (_MSC_VER) && (_MSC_VER >= 1500)
+/* Visual studio 2008 and later has _Pragma */
+
+#include <stdlib.h>
+
+#define G_HAS_CONSTRUCTORS 1
+
+/* We do some weird things to avoid the constructors being optimized
+ * away on VS2015 if WholeProgramOptimization is enabled. First we
+ * make a reference to the array from the wrapper to make sure its
+ * references. Then we use a pragma to make sure the wrapper function
+ * symbol is always included at the link stage. Also, the symbols
+ * need to be extern (but not dllexport), even though they are not
+ * really used from another object file.
+ */
+
+/* We need to account for differences between the mangling of symbols
+ * for Win32 (x86) and x64 programs, as symbols on Win32 are prefixed
+ * with an underscore but symbols on x64 are not.
+ */
+#ifdef _WIN64
+#define G_MSVC_SYMBOL_PREFIX ""
+#else
+#define G_MSVC_SYMBOL_PREFIX "_"
+#endif
+
+#define G_DEFINE_CONSTRUCTOR(_func) G_MSVC_CTOR (_func, G_MSVC_SYMBOL_PREFIX)
+#define G_DEFINE_DESTRUCTOR(_func) G_MSVC_DTOR (_func, G_MSVC_SYMBOL_PREFIX)
+
+#define G_MSVC_CTOR(_func,_sym_prefix) \
+  static void _func(void); \
+  extern int (* _array ## _func)(void);              \
+  int _func ## _wrapper(void) { _func(); g_slist_find (NULL,  _array ## _func); return 0; } \
+  __pragma(comment(linker,"/include:" _sym_prefix # _func "_wrapper")) \
+  __pragma(section(".CRT$XCU",read)) \
+  __declspec(allocate(".CRT$XCU")) int (* _array ## _func)(void) = _func ## _wrapper;
+
+#define G_MSVC_DTOR(_func,_sym_prefix) \
+  static void _func(void); \
+  extern int (* _array ## _func)(void);              \
+  int _func ## _constructor(void) { atexit (_func); g_slist_find (NULL,  _array ## _func); return 0; } \
+   __pragma(comment(linker,"/include:" _sym_prefix # _func "_constructor")) \
+  __pragma(section(".CRT$XCU",read)) \
+  __declspec(allocate(".CRT$XCU")) int (* _array ## _func)(void) = _func ## _constructor;
+
+#elif defined (_MSC_VER)
+
+#define G_HAS_CONSTRUCTORS 1
+
+/* Pre Visual studio 2008 must use #pragma section */
+#define G_DEFINE_CONSTRUCTOR_NEEDS_PRAGMA 1
+#define G_DEFINE_DESTRUCTOR_NEEDS_PRAGMA 1
+
+#define G_DEFINE_CONSTRUCTOR_PRAGMA_ARGS(_func) \
+  section(".CRT$XCU",read)
+#define G_DEFINE_CONSTRUCTOR(_func) \
+  static void _func(void); \
+  static int _func ## _wrapper(void) { _func(); return 0; } \
+  __declspec(allocate(".CRT$XCU")) static int (*p)(void) = _func ## _wrapper;
+
+#define G_DEFINE_DESTRUCTOR_PRAGMA_ARGS(_func) \
+  section(".CRT$XCU",read)
+#define G_DEFINE_DESTRUCTOR(_func) \
+  static void _func(void); \
+  static int _func ## _constructor(void) { atexit (_func); return 0; } \
+  __declspec(allocate(".CRT$XCU")) static int (* _array ## _func)(void) = _func ## _constructor;
+
+#elif defined(__SUNPRO_C)
+
+/* This is not tested, but i believe it should work, based on:
+ * http://opensource.apple.com/source/OpenSSL098/OpenSSL098-35/src/fips/fips_premain.c
+ */
+
+#define G_HAS_CONSTRUCTORS 1
+
+#define G_DEFINE_CONSTRUCTOR_NEEDS_PRAGMA 1
+#define G_DEFINE_DESTRUCTOR_NEEDS_PRAGMA 1
+
+#define G_DEFINE_CONSTRUCTOR_PRAGMA_ARGS(_func) \
+  init(_func)
+#define G_DEFINE_CONSTRUCTOR(_func) \
+  static void _func(void);
+
+#define G_DEFINE_DESTRUCTOR_PRAGMA_ARGS(_func) \
+  fini(_func)
+#define G_DEFINE_DESTRUCTOR(_func) \
+  static void _func(void);
+
+#else
+
+/* constructors not supported for this compiler */
+
+#endif
+
+#endif /* __GTK_DOC_IGNORE__ */

libmalcontent/init.c

@@ -0,0 +1,51 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*-
+ *
+ * Copyright © 2020 Endless Mobile, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * Authors:
+ *  - Philip Withnall <withnall@endlessm.com>
+ */
+
+#include "config.h"
+
+#include <glib/gi18n-lib.h>
+#include "gconstructor.h"
+
+
+static void
+mct_init (void)
+{
+  bindtextdomain (GETTEXT_PACKAGE, PACKAGE_LOCALE_DIR);
+  bind_textdomain_codeset (GETTEXT_PACKAGE, "UTF-8");
+}
+
+#ifdef G_HAS_CONSTRUCTORS
+
+#ifdef G_DEFINE_CONSTRUCTOR_NEEDS_PRAGMA
+#pragma G_DEFINE_CONSTRUCTOR_PRAGMA_ARGS(mct_init_ctor)
+#endif
+G_DEFINE_CONSTRUCTOR(mct_init_ctor)
+
+static void
+mct_init_ctor (void)
+{
+  mct_init ();
+}
+
+#else
+#error Your platform/compiler is missing constructor support
+#endif

libmalcontent/meson.build

@@ -2,6 +2,7 @@ libmalcontent_api_version = '0'
 libmalcontent_api_name = 'malcontent-' + libmalcontent_api_version
 libmalcontent_sources = [
   'app-filter.c',
+  'init.c',
   'manager.c',
   'session-limits.c',
 ]
@@ -13,6 +14,7 @@ libmalcontent_headers = [
 ]
 libmalcontent_private_headers = [
   'app-filter-private.h',
+  'gconstructor.h',
   'session-limits-private.h',
 ]