Dynamically bind ALSA, so binaries compiled with ALSA will work on systems

without ALSA installed.
2003-11-03 21:52:31 +00:00
parent 78908329f8
commit 928a8ce1af
7 changed files with 227 additions and 86 deletions
@@ -0,0 +1,59 @@
+#include "global.h"
+
+#include <dlfcn.h>
+
+#define ALSA_PCM_NEW_HW_PARAMS_API
+#define ALSA_PCM_NEW_SW_PARAMS_API
+#include <alsa/asoundlib.h>
+
+static void *Handle = NULL;
+
+#include "RageUtil.h"
+#include "ALSA9Dynamic.h"
+
+/* foo_f dfoo = NULL */
+#define FUNC(ret, name, proto) name##_f d##name = NULL
+#include "ALSA9Functions.h"
+#undef FUNC
+
+static const CString lib = "libasound.so.2";
+CString LoadALSA()
+{
+	ASSERT( Handle == NULL );
+
+	Handle = dlopen( lib, RTLD_NOW );
+	if( Handle == NULL )
+		return ssprintf("dlopen(%s): %s", lib.c_str(), dlerror());
+
+	CString error;
+	/* Eww.  The "new" HW and SW API functions are really prefixed by __,
+	 * eg. __snd_pcm_hw_params_set_rate_near. */
+#define FUNC(ret, name, proto) \
+	d##name = (name##_f) dlsym(Handle, "__" #name); \
+	if( !d##name ) { \
+		d##name = (name##_f) dlsym(Handle, #name); \
+		if( !d##name ) { \
+			error="Couldn't load symbol " #name; \
+			goto error; \
+		} \
+	}
+#include "ALSA9Functions.h"
+#undef FUNC
+
+	return "";
+error:
+	UnloadALSA();
+	if( Handle )
+		dlclose( Handle );
+	Handle = NULL;
+	return error;
+}
+
+void UnloadALSA()
+{
+	dlclose( Handle );
+#define FUNC(ret, name, proto) d##name = NULL;
+#include "ALSA9Functions.h"
+#undef FUNC
+}
+