lib/alsa/Version: wrapper for snd_asoundlib_version()

Makefile.am

@@ -257,6 +257,7 @@ UPNP_SOURCES = \
 	src/lib/upnp/Action.hxx
 
 ALSA_SOURCES = \
+	src/lib/alsa/Version.cxx src/lib/alsa/Version.hxx \
 	src/lib/alsa/NonBlock.cxx src/lib/alsa/NonBlock.hxx
 
 #

src/lib/alsa/Version.cxx

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2003-2017 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * 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 2 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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "Version.hxx"
+
+#include <alsa/asoundlib.h>
+
+gcc_pure
+static uint_least32_t
+ParseAlsaVersion(const char *p)
+{
+	char *endptr;
+	unsigned long major, minor = 0, subminor = 0;
+
+	major = strtoul(p, &endptr, 10);
+	if (*endptr == '.') {
+		p = endptr + 1;
+		minor = strtoul(p, &endptr, 10);
+		if (*endptr == '.') {
+			p = endptr + 1;
+			subminor = strtoul(p, nullptr, 10);
+		}
+	}
+
+	return MakeAlsaVersion(major, minor, subminor);
+}
+
+uint_least32_t
+GetRuntimeAlsaVersion()
+{
+	const char *version = snd_asoundlib_version();
+	if (version == nullptr)
+		return 0;
+
+	return ParseAlsaVersion(version);
+}

src/lib/alsa/Version.hxx

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2003-2017 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * 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 2 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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_ALSA_VERSION_HXX
+#define MPD_ALSA_VERSION_HXX
+
+#include "Compiler.h"
+
+#include <stdint.h>
+
+static constexpr uint_least32_t
+MakeAlsaVersion(uint_least32_t major, uint_least32_t minor,
+		uint_least32_t subminor)
+{
+	return (major << 16) | (minor << 8) | subminor;
+}
+
+/**
+ * Wrapper for snd_asoundlib_version() which translates the resulting
+ * string to an integer constructed with MakeAlsaVersion().
+ */
+gcc_const
+uint_least32_t
+GetRuntimeAlsaVersion();
+
+#endif