[COMMITTED] ada: Make internal_error_function more robust

[Marc Poulhiès via Gcc-patches]

From: Eric Botcazou <ebotca...@adacore.com>

gcc/ada/

        * gcc-interface/misc.cc (internal_error_function): Be prepared for
        an input_location set to UNKNOWN_LOCATION.

Tested on x86_64-pc-linux-gnu, committed on master.

---
 gcc/ada/gcc-interface/misc.cc | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/gcc/ada/gcc-interface/misc.cc b/gcc/ada/gcc-interface/misc.cc
index 56c7bb9b533..30319ae58b1 100644
--- a/gcc/ada/gcc-interface/misc.cc
+++ b/gcc/ada/gcc-interface/misc.cc
@@ -330,13 +330,23 @@ internal_error_function (diagnostic_context *context, 
const char *msgid,
   sp.Bounds = &temp;
   sp.Array = buffer;
 
-  xloc = expand_location (input_location);
-  if (context->show_column && xloc.column != 0)
-    loc = xasprintf ("%s:%d:%d", xloc.file, xloc.line, xloc.column);
+  if (input_location == UNKNOWN_LOCATION)
+    {
+      loc = NULL;
+      temp_loc.Low_Bound = 1;
+      temp_loc.High_Bound = 0;
+    }
   else
-    loc = xasprintf ("%s:%d", xloc.file, xloc.line);
-  temp_loc.Low_Bound = 1;
-  temp_loc.High_Bound = strlen (loc);
+    {
+      xloc = expand_location (input_location);
+      if (context->show_column && xloc.column != 0)
+       loc = xasprintf ("%s:%d:%d", xloc.file, xloc.line, xloc.column);
+      else
+       loc = xasprintf ("%s:%d", xloc.file, xloc.line);
+      temp_loc.Low_Bound = 1;
+      temp_loc.High_Bound = strlen (loc);
+    }
+
   sp_loc.Bounds = &temp_loc;
   sp_loc.Array = loc;
 
-- 
2.40.0