Enable builds with musl

configure.ac

@@ -1074,6 +1074,12 @@ case $host_os in
         esac
         ;;
     esac
+
+    # Stamp $ORIGIN in the default rpath so musl loads sibling DLLs. glibc doesn't need this: the
+    # DLLs were already loaded by absolute path and glibc recognises them as the same (based on
+    # basename).
+    # Must come last. Value ends up in a makefile, hence the double dollar.
+    WINE_TRY_CFLAGS([-Wl,-rpath,\\\$ORIGIN],[UNIXLDFLAGS="$UNIXLDFLAGS '-Wl,-rpath,\$\$ORIGIN'"])
     ;;
 esac
 

dlls/ntdll/unix/loader.c

@@ -39,6 +39,11 @@
 #include <sys/wait.h>
 #include <unistd.h>
 #include <malloc.h>
+#ifndef M_PERTURB
+/* musl does not implement mallopt(). Only used for debugging; use a no-op. */
+#define M_PERTURB 0
+static inline int mallopt( int param, int value ) { return 1; }
+#endif
 #include <dlfcn.h>
 #ifdef HAVE_PWD_H
 # include <pwd.h>

dlls/winegstreamer/media-converter/media-converter.h

@@ -28,6 +28,7 @@
 #include <inttypes.h>
 #include <unistd.h>
 #include <fcntl.h>
+#include <pthread.h>
 #include <sys/stat.h>
 
 #include "unix_private.h"

loader/preloader.c

@@ -1515,7 +1515,10 @@ void* wld_start( void **stack )
     /* expose ld.so _r_debug as a separate namespace in r_next */
     ld_so_r_debug = find_symbol( &ld_so_map, "_r_debug", STT_OBJECT );
     if (ld_so_r_debug) _r_debug.r_next = (struct wld_r_debug_extended *)ld_so_r_debug;
+#ifdef __GLIBC__
+    /* musl has no _r_debug; ignore */
     else wld_printf( "_r_debug not found in ld.so\n" );
+#endif
 
     _r_debug_state(); /* notify GDB that _r_debug is ready */