FFI: Resolve ld script redirection in ffi.load().

1 files changed, 32 insertions, 1 deletions

diff --git a/src/lj_clib.c b/src/lj_clib.c
index d7721860..7b9b6c1a 100644
--- a/src/lj_clib.c
+++ b/src/lj_clib.c
@@ -22,6 +22,7 @@
 #if LJ_TARGET_DLOPEN
 
 #include <dlfcn.h>
+#include <stdio.h>
 
 #if defined(RTLD_DEFAULT)
 #define CLIB_DEFHANDLE  RTLD_DEFAULT
@@ -59,11 +60,41 @@ static const char *clib_extname(lua_State *L, const char *name)
   return name;
 }
 
+/* Quick and dirty solution to resolve shared library name from ld script. */
+static const char *clib_resolve_lds(lua_State *L, const char *name)
+{
+  FILE *fp = fopen(name, "r");
+  if (fp) {
+    char *p, *e, buf[256];
+    if (fgets(buf, sizeof(buf), fp) && !strncmp(buf, "/* GNU ld script", 16)) {
+      while (fgets(buf, sizeof(buf), fp)) {
+        if (!strncmp(buf, "GROUP", 5) && (p = strchr(buf, '('))) {
+          while (*++p == ' ') ;
+          for (e = p; *e && *e != ' ' && *e != ')'; e++) ;
+          fclose(fp);
+          return strdata(lj_str_new(L, p, e-p));
+        }
+      }
+    }
+    fclose(fp);
+  }
+  return NULL;
+}
+
 static void *clib_loadlib(lua_State *L, const char *name, int global)
 {
   void *h = dlopen(clib_extname(L, name),
                    RTLD_LAZY | (global?RTLD_GLOBAL:RTLD_LOCAL));
-  if (!h) clib_error_(L);
+  if (!h) {
+    const char *e, *err = dlerror();
+    if (*err == '/' && (e = strchr(err, ':')) &&
+        (name = clib_resolve_lds(L, strdata(lj_str_new(L, err, e-err))))) {
+      h = dlopen(name, RTLD_LAZY | (global?RTLD_GLOBAL:RTLD_LOCAL));
+      if (h) return h;
+      err = dlerror();
+    }
+    lj_err_callermsg(L, err);
+  }
   return h;
 }