Don't trust templates from DW_AT_nameusers/simark/template-suffix

With gcc 8 (and clang?) the non-type template arguments (constants)
don't include the integer suffixes anymore.  For example, with

  template <unsigned int X>
  class foo
  {
    ...
  };

  foo<10u>

used to generate foo<10u> as the DW_AT_name, now it generates foo<10>.
This is a problem when things look up "foo<10u>" and don't find it.  For
example, when trying to print an instance of that class through a base
class pointer, GDB would first demangle the symbol for that class'
vtable, which would give "vtable for foo<10u>".  GDB would then take the
"foo<10u>" from that string and try to look up the type.  With the new
DW_AT_name, it would fail to look it up, and fail to print the value.

This patch makes it so GDB doesn't trust the templates contained in
DW_AT_name.  Instead, it re-builds the name from the DW_AT_template_*
DIES in the format that it expects (with the integer suffixes).

1 files changed, 15 insertions, 0 deletions

diff --git a/gdb/c-valprint.c b/gdb/c-valprint.c
index c4c0918..12b9086 100644
--- a/gdb/c-valprint.c
+++ b/gdb/c-valprint.c
@@ -454,6 +454,21 @@ c_val_print_int (struct type *type, struct type *unresolved_type,
 		     : options->output_format);
       val_print_scalar_formatted (type, embedded_offset,
 				  original_value, &opts, 0, stream);
+
+      if (opts.print_suffix)
+	{
+	  struct type *t = check_typedef (type);
+
+	  if (TYPE_UNSIGNED (t))
+	    fputc_filtered ('u', stream);
+
+	  /* Is there a better way to do this?  Just looking at the size doesn't
+	     work.  */
+	  if (strstr (TYPE_NAME (t), "long long") != NULL)
+	    fputs_filtered ("ll", stream);
+	  else if (strstr (TYPE_NAME (t), "long") != NULL)
+	    fputc_filtered ('l', stream);
+	}
     }
   else
     {