[PATCH] dlltool: Use the output name as basis for deterministic temp prefixes

["Martin Storsjö" <martin@martin.st>]

When running multiple dlltool processes in parallel, a temp prefix
based on the dll name can cause clashes, if building multiple
import libraries that have the same DLL name.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28885
---
 binutils/dlltool.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/binutils/dlltool.c b/binutils/dlltool.c
index d95bf3f5470..89871510b45 100644
--- a/binutils/dlltool.c
+++ b/binutils/dlltool.c
@@ -3992,10 +3992,11 @@ main (int ac, char **av)
   if (tmp_prefix == NULL)
     {
       /* If possible use a deterministic prefix.  */
-      if (dll_name)
+      if (imp_name || delayimp_name)
         {
-          tmp_prefix = xmalloc (strlen (dll_name) + 2);
-          sprintf (tmp_prefix, "%s_", dll_name);
+          const char *input = imp_name ? imp_name : delayimp_name;
+          tmp_prefix = xmalloc (strlen (input) + 2);
+          sprintf (tmp_prefix, "%s_", input);
           for (i = 0; tmp_prefix[i]; i++)
             if (!ISALNUM (tmp_prefix[i]))
               tmp_prefix[i] = '_';
-- 
2.25.1