girepository: Add version macros and functions. Fixes #200

This adds the following macros and functions: GI_MAJOR_VERSION, GI_MICRO_VERSION,
GI_MINOR_VERSION, GI_CHECK_VERSION, gi_get_major_version,gi_get_micro_version,
gi_get_minor_version.

Since we share a prefix with glib we have to namespace these by using the gi_
prefix. g_gi would also work but we already export symbols with gi_ like
gi_cclosure_marshal_generic(), gi_type_tag_get_ffi_type() and
gi_type_info_extract_ffi_return_value(), so let's not add another naming scheme.

girepository.h

@@ -47,6 +47,7 @@
 #include <giunioninfo.h>
 #include <giversionmacros.h>
 #include <givfuncinfo.h>
+#include <giversion.h>
 
 G_BEGIN_DECLS
 

giversion.c

@@ -0,0 +1,114 @@
+/* Copyright (C) 2018 Christoph Reiter
+ *
+ * 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 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., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include "config.h"
+
+#include <girepository.h>
+
+/**
+ * SECTION:giversion
+ * @Title: Version Information
+ * @Short_description: macros and functions to check the girepository version
+ */
+
+/**
+ * GI_MAJOR_VERSION:
+ *
+ * The major version number of the girepository library.
+ *
+ * Since: 1.60
+ */
+
+/**
+ * GI_MINOR_VERSION:
+ *
+ * The minor version number of the girepository library.
+ *
+ * Since: 1.60
+ */
+
+/**
+ * GI_MICRO_VERSION:
+ *
+ * The micro version number of the girepository library.
+ *
+ * Since: 1.60
+ */
+
+/**
+ * GI_CHECK_VERSION:
+ * @major: the major version to check for
+ * @minor: the minor version to check for
+ * @micro: the micro version to check for
+ *
+ * Checks the version of the girepository library that is being compiled
+ * against.
+ *
+ * Returns: %TRUE if the version of the girepository header files
+ * is the same as or newer than the passed-in version.
+ *
+ * Since: 1.60
+ */
+
+/**
+ * gi_get_major_version:
+ *
+ * Returns the major version number of the girepository library.
+ * (e.g. in version 1.58.2 this is 1.)
+ *
+ * Returns: the major version number of the girepository library
+ *
+ * Since: 1.60
+ */
+guint
+gi_get_major_version (void)
+{
+  return GI_MAJOR_VERSION;
+}
+
+/**
+ * gi_get_minor_version:
+ *
+ * Returns the minor version number of the girepository library.
+ * (e.g. in version 1.58.2 this is 58.)
+ *
+ * Returns: the minor version number of the girepository library
+ *
+ * Since: 1.60
+ */
+guint
+gi_get_minor_version (void)
+{
+  return GI_MINOR_VERSION;
+}
+
+/**
+ * gi_get_micro_version:
+ *
+ * Returns the micro version number of the girepository library.
+ * (e.g. in version 1.58.2 this is 2.)
+ *
+ * Returns: the micro version number of the girepository library
+ *
+ * Since: 1.60
+ */
+guint
+gi_get_micro_version (void)
+{
+  return GI_MICRO_VERSION;
+}

giversion.h.in

@@ -0,0 +1,47 @@
+/* Copyright (C) 2018 Christoph Reiter
+ *
+ * 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 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., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifndef __GIVERISON_H__
+#define __GIVERISON_H__
+
+#if !defined (__GIREPOSITORY_H_INSIDE__) && !defined (GI_COMPILATION)
+#error "Only <girepository.h> can be included directly."
+#endif
+
+G_BEGIN_DECLS
+
+#define GI_MAJOR_VERSION @GI_MAJOR_VERSION@
+#define GI_MINOR_VERSION @GI_MINOR_VERSION@
+#define GI_MICRO_VERSION @GI_MICRO_VERSION@
+
+#define GI_CHECK_VERSION(major,minor,micro) \
+    (GI_MAJOR_VERSION > (major) || \
+     (GI_MAJOR_VERSION == (major) && GI_MINOR_VERSION > (minor)) || \
+     (GI_MAJOR_VERSION == (major) && GI_MINOR_VERSION == (minor) && \
+      GI_MICRO_VERSION >= (micro)))
+
+GI_AVAILABLE_IN_1_60
+guint gi_get_major_version (void) G_GNUC_CONST;
+GI_AVAILABLE_IN_1_60
+guint gi_get_minor_version (void) G_GNUC_CONST;
+GI_AVAILABLE_IN_1_60
+guint gi_get_micro_version (void) G_GNUC_CONST;
+
+G_END_DECLS
+
+#endif  /* __GIVERISON_H__ */

giversionmacros.h

@@ -153,4 +153,10 @@
 # define GI_AVAILABLE_IN_1_46                 _GI_EXTERN
 #endif
 
+#if defined(GLIB_VERSION_2_60) && GLIB_VERSION_MAX_ALLOWED < GLIB_VERSION_2_60
+# define GI_AVAILABLE_IN_1_60                 GLIB_UNAVAILABLE(2, 60)
+#else
+# define GI_AVAILABLE_IN_1_60                 _GI_EXTERN
+#endif
+
 #endif /* __GIVERSIONMACROS_H__ */

meson.build

@@ -36,6 +36,12 @@ girepo_internals_dep = declare_dependency(
   include_directories: include_directories('.'),
 )
 
+gi_version_h = configure_file(
+  configuration: config,
+  input: 'giversion.h.in',
+  output: 'giversion.h',
+)
+
 girepo_headers = [
   'giarginfo.h',
   'gibaseinfo.h',
@@ -58,6 +64,7 @@ girepo_headers = [
   'giunioninfo.h',
   'giversionmacros.h',
   'givfuncinfo.h',
+  gi_version_h,
 ]
 
 girepo_sources = [
@@ -81,6 +88,7 @@ girepo_sources = [
   'gitypeinfo.c',
   'gitypelib.c',
   'giunioninfo.c',
+  'giversion.c',
   'givfuncinfo.c',
 ]
 
@@ -102,6 +110,7 @@ girepo_gir_sources = files(
   'gistructinfo.c',
   'gitypeinfo.c',
   'giunioninfo.c',
+  'giversion.c',
   'givfuncinfo.c',
   'giarginfo.h',
   'gibaseinfo.h',
@@ -122,7 +131,8 @@ girepo_gir_sources = files(
   'gitypes.h',
   'giunioninfo.h',
   'givfuncinfo.h',
-)
+) + [gi_version_h]
+
 
 install_headers(girepo_headers, subdir: 'gobject-introspection-1.0')