[template-glib] build: add version macro API

[Christian Hergert <chergert src gnome org>]

commit 5d9a4a33d15a622950e351bc24fbb078613222f2
Author: Christian Hergert <chergert redhat com>
Date:   Wed Nov 8 13:42:32 2017 -0800

    build: add version macro API

 src/meson.build           |    1 +
 src/tmpl-glib.h           |    2 +
 src/tmpl-version-macros.h |  131 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 134 insertions(+), 0 deletions(-)
---
diff --git a/src/meson.build b/src/meson.build
index f07bb62..3398f62 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -50,6 +50,7 @@ libtemplate_glib_public_headers = [
   'tmpl-symbol.h',
   'tmpl-template-locator.h',
   'tmpl-template.h',
+  'tmpl-version-macros.h',
 ]
 
 libtemplate_glib_public_sources = [
diff --git a/src/tmpl-glib.h b/src/tmpl-glib.h
index a2aaf31..0d67a11 100644
--- a/src/tmpl-glib.h
+++ b/src/tmpl-glib.h
@@ -33,6 +33,8 @@ G_BEGIN_DECLS
 # include "tmpl-symbol.h"
 # include "tmpl-template.h"
 # include "tmpl-template-locator.h"
+# include "tmpl-version.h"
+# include "tmpl-version-macros.h"
 #undef TMPL_GLIB_INSIDE
 
 G_END_DECLS
diff --git a/src/tmpl-version-macros.h b/src/tmpl-version-macros.h
new file mode 100644
index 0000000..d424844
--- /dev/null
+++ b/src/tmpl-version-macros.h
@@ -0,0 +1,131 @@
+/* tmpl-version-macros.h
+ *
+ * Copyright (C) 2017 Christian Hergert <chergert redhat com>
+ *
+ * This file 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 file 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 General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef TMPL_VERSION_MACROS_H
+#define TMPL_VERSION_MACROS_H
+
+#if !defined(TMPL_GLIB_INSIDE) && !defined(TMPL_GLIB_COMPILATION)
+# error "Only <tmpl-glib.h> can be included directly."
+#endif
+
+#include <glib.h>
+
+#include "tmpl-version.h"
+
+#ifndef _TMPL_EXTERN
+#define _TMPL_EXTERN extern
+#endif
+
+#ifdef TMPL_DISABLE_DEPRECATION_WARNINGS
+#define TMPL_DEPRECATED _TMPL_EXTERN
+#define TMPL_DEPRECATED_FOR(f) _TMPL_EXTERN
+#define TMPL_UNAVAILABLE(maj,min) _TMPL_EXTERN
+#else
+#define TMPL_DEPRECATED G_DEPRECATED _TMPL_EXTERN
+#define TMPL_DEPRECATED_FOR(f) G_DEPRECATED_FOR(f) _TMPL_EXTERN
+#define TMPL_UNAVAILABLE(maj,min) G_UNAVAILABLE(maj,min) _TMPL_EXTERN
+#endif
+
+#define TMPL_VERSION_3_28 (G_ENCODE_VERSION (3, 28))
+
+#if (TMPL_MINOR_VERSION == 99)
+# define TMPL_VERSION_CUR_STABLE (G_ENCODE_VERSION (TMPL_MAJOR_VERSION + 1, 0))
+#elif (TMPL_MINOR_VERSION % 2)
+# define TMPL_VERSION_CUR_STABLE (G_ENCODE_VERSION (TMPL_MAJOR_VERSION, TMPL_MINOR_VERSION + 1))
+#else
+# define TMPL_VERSION_CUR_STABLE (G_ENCODE_VERSION (TMPL_MAJOR_VERSION, TMPL_MINOR_VERSION))
+#endif
+
+#if (TMPL_MINOR_VERSION == 99)
+# define TMPL_VERSION_PREV_STABLE (G_ENCODE_VERSION (TMPL_MAJOR_VERSION + 1, 0))
+#elif (TMPL_MINOR_VERSION % 2)
+# define TMPL_VERSION_PREV_STABLE (G_ENCODE_VERSION (TMPL_MAJOR_VERSION, TMPL_MINOR_VERSION - 1))
+#else
+# define TMPL_VERSION_PREV_STABLE (G_ENCODE_VERSION (TMPL_MAJOR_VERSION, TMPL_MINOR_VERSION - 2))
+#endif
+
+/**
+ * TMPL_VERSION_MIN_REQUIRED:
+ *
+ * A macro that should be defined by the user prior to including
+ * the tmpl-glib.h header.
+ *
+ * The definition should be one of the predefined TMPL version
+ * macros: %TMPL_VERSION_3_28, ...
+ *
+ * This macro defines the lower bound for the Template-GLib API to use.
+ *
+ * If a function has been deprecated in a newer version of Template-GLib,
+ * it is possible to use this symbol to avoid the compiler warnings
+ * without disabling warning for every deprecated function.
+ *
+ * Since: 3.28
+ */
+#ifndef TMPL_VERSION_MIN_REQUIRED
+# define TMPL_VERSION_MIN_REQUIRED (TMPL_VERSION_CUR_STABLE)
+#endif
+
+/**
+ * TMPL_VERSION_MAX_ALLOWED:
+ *
+ * A macro that should be defined by the user prior to including
+ * the tmpl-glib.h header.
+
+ * The definition should be one of the predefined Template-GLib version
+ * macros: %TMPL_VERSION_1_0, %TMPL_VERSION_1_2,...
+ *
+ * This macro defines the upper bound for the TMPL API to use.
+ *
+ * If a function has been introduced in a newer version of Template-GLib,
+ * it is possible to use this symbol to get compiler warnings when
+ * trying to use that function.
+ *
+ * Since: 3.28
+ */
+#ifndef TMPL_VERSION_MAX_ALLOWED
+# if TMPL_VERSION_MIN_REQUIRED > TMPL_VERSION_PREV_STABLE
+#  define TMPL_VERSION_MAX_ALLOWED (TMPL_VERSION_MIN_REQUIRED)
+# else
+#  define TMPL_VERSION_MAX_ALLOWED (TMPL_VERSION_CUR_STABLE)
+# endif
+#endif
+
+#if TMPL_VERSION_MAX_ALLOWED < TMPL_VERSION_MIN_REQUIRED
+#error "TMPL_VERSION_MAX_ALLOWED must be >= TMPL_VERSION_MIN_REQUIRED"
+#endif
+#if TMPL_VERSION_MIN_REQUIRED < TMPL_VERSION_3_28
+#error "TMPL_VERSION_MIN_REQUIRED must be >= TMPL_VERSION_3_28"
+#endif
+
+#define TMPL_AVAILABLE_IN_ALL                   _TMPL_EXTERN
+
+#if TMPL_VERSION_MIN_REQUIRED >= TMPL_VERSION_3_28
+# define TMPL_DEPRECATED_IN_3_28                TMPL_DEPRECATED
+# define TMPL_DEPRECATED_IN_3_28_FOR(f)         TMPL_DEPRECATED_FOR(f)
+#else
+# define TMPL_DEPRECATED_IN_3_28                _TMPL_EXTERN
+# define TMPL_DEPRECATED_IN_3_28_FOR(f)         _TMPL_EXTERN
+#endif
+
+#if TMPL_VERSION_MAX_ALLOWED < TMPL_VERSION_3_28
+# define TMPL_AVAILABLE_IN_3_28                 TMPL_UNAVAILABLE(3, 28)
+#else
+# define TMPL_AVAILABLE_IN_3_28                 _TMPL_EXTERN
+#endif
+
+#endif /* TMPL_VERSION_MACROS_H */