Generate a header containing git version info

It contains the last annotated tag, and possibly also the number of
commits since then and the hash of the last commit.

src/common/config/meson.build

@@ -0,0 +1,8 @@
+# Generate a file containing the last annotated git tag and possibly also the
+# amount of commits since then and the hash of the last commit
+vcs_tag(
+  command : ['git', 'describe', '--always'],
+  input : 'version.h.in',
+  output : 'version.h',
+  replace_string : '@VCS_VERSION@'
+)

src/common/config/version.h.in

@@ -0,0 +1,24 @@
+// yabridge: a Wine VST bridge
+// Copyright (C) 2020  Robbert van der Helm
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program 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 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 <https://www.gnu.org/licenses/>.
+
+#pragma once
+
+/**
+ * Will be replaced with the output of `git describe` by Meson. Contains the
+ * latest annotated tag and possibly also the amount of commits and the hash of
+ * the last commit.
+ */
+constexpr char yabridge_git_version[] = "@VCS_VERSION@";