gdb/fortran: Support negative array stride in one limited case

[deliverable/binutils-gdb.git] / gdb / gdbtypes.c

diff --git a/gdb/gdbtypes.c b/gdb/gdbtypes.c
index 85758930491f92a6eaac8dc7a80e4eefd38d3afd..ef110b30445f82cc464240a2ed55e3ce08500729 100644 (file)
--- a/gdb/gdbtypes.c
+++ b/gdb/gdbtypes.c
@@ -1223,7 +1223,7 @@ create_array_type_with_stride (struct type *result_type,
          && !type_not_allocated (result_type)))
     {
       LONGEST low_bound, high_bound;
-      unsigned int stride;
+      int stride;
 
       /* If the array itself doesn't provide a stride value then take
         whatever stride the range provides.  Don't update BIT_STRIDE as
@@ -1241,9 +1241,18 @@ create_array_type_with_stride (struct type *result_type,
         In such cases, the array length should be zero.  */
       if (high_bound < low_bound)
        TYPE_LENGTH (result_type) = 0;
-      else if (stride > 0)
-       TYPE_LENGTH (result_type) =
-         (stride * (high_bound - low_bound + 1) + 7) / 8;
+      else if (stride != 0)
+       {
+         /* Ensure that the type length is always positive, even in the
+            case where (for example in Fortran) we have a negative
+            stride.  It is possible to have a single element array with a
+            negative stride in Fortran (this doesn't mean anything
+            special, it's still just a single element array) so do
+            consider that case when touching this code.  */
+         LONGEST element_count = abs (high_bound - low_bound + 1);
+         TYPE_LENGTH (result_type)
+           = ((abs (stride) * element_count) + 7) / 8;
+       }
       else
        TYPE_LENGTH (result_type) =
          TYPE_LENGTH (element_type) * (high_bound - low_bound + 1);