LTO: fallback to -flto=N if -flto=jobserver does not work.

gcc/ChangeLog:

	* lto-wrapper.c (run_gcc): When -flto=jobserver is used, but the
	makeserver cannot be detected, then use -flto=N fallback.

diff --git a/gcc/lto-wrapper.c b/gcc/lto-wrapper.c
index ea68490163dfa2f2e16c8894b585d216c864eb9c..6ba401007f6591ece5030289f53f4b2e4d933d0b 100644 (file)
--- a/gcc/lto-wrapper.c
+++ b/gcc/lto-wrapper.c
@@ -1483,8 +1483,9 @@ run_gcc (unsigned argc, char *argv[])
       if (jobserver && jobserver_error != NULL)
        {
          warning (0, jobserver_error);
-         parallel = 0;
+         /* Fall back to auto parallelism.  */
          jobserver = 0;
+         auto_parallel = 1;
        }
       else if (!jobserver && jobserver_error == NULL)
        {