support: Add xdlvsym function

3 files changed, 26 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index a354988..07d1bd6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2019-06-28  Florian Weimer  <fweimer@redhat.com>
 
+	* support/xdlfcn.h (xdlvsym): Declare function.
+	* support/xdlfcn.c (xdlvsym): Define funciton.
+
+2019-06-28  Florian Weimer  <fweimer@redhat.com>
+
 	[BZ #24744]
 	io: Remove the copy_file_range emulation.
 	* sysdeps/unix/sysv/linux/copy_file_range.c (copy_file_range): Do
diff --git a/support/xdlfcn.c b/support/xdlfcn.c
index b2e5c21..11fe489 100644
--- a/support/xdlfcn.c
+++ b/support/xdlfcn.c
@@ -51,6 +51,26 @@ xdlsym (void *handle, const char *symbol)
   return sym;
 }
 
+void *
+xdlvsym (void *handle, const char *symbol, const char *version)
+{
+  /* Clear any pending errors.  */
+  dlerror ();
+
+  void *sym = dlvsym (handle, symbol, version);
+
+  if (sym == NULL)
+    {
+      const char *error = dlerror ();
+      if (error != NULL)
+        FAIL_EXIT1 ("error: dlvsym: %s\n", error);
+      /* If there was no error, we found a NULL symbol.  Return the
+         NULL value in this case.  */
+    }
+
+  return sym;
+}
+
 void
 xdlclose (void *handle)
 {
diff --git a/support/xdlfcn.h b/support/xdlfcn.h
index c9cd810..7f8d493 100644
--- a/support/xdlfcn.h
+++ b/support/xdlfcn.h
@@ -27,6 +27,7 @@ __BEGIN_DECLS
 void *xdlopen (const char *filename, int flags);
 void *xdlmopen (Lmid_t lmid, const char *filename, int flags);
 void *xdlsym (void *handle, const char *symbol);
+void *xdlvsym (void *handle, const char *symbol, const char *version);
 void xdlclose (void *handle);
 
 __END_DECLS