gdb: add asserts to gdbarch_register_name

This commit adds asserts to gdbarch_register_name that validate the
parameters, and the return value.

The interesting thing here is that gdbarch_register_name is generated
by gdbarch.py, and so, to add these asserts, I need to update the
generation script.

I've added two new arguments for Functions and Methods (as declared in
gdbarch-components.py), these arguments are 'param_checks' and
'result_checks'.  Each of these new arguments can be used to list some
expressions that are then used within gdb_assert calls in the
generated code.

The asserts that validate the API as described in the comment I added
to gdbarch_register_name a few commits back; the register number
passed in needs to be a valid cooked register number, and the result
being returned should not be nullptr.

1 files changed, 5 insertions, 1 deletions

diff --git a/gdb/gdbarch.c b/gdb/gdbarch.c
index be73d39..4b0c10b 100644
--- a/gdb/gdbarch.c
+++ b/gdb/gdbarch.c
@@ -2235,9 +2235,13 @@ gdbarch_register_name (struct gdbarch *gdbarch, int regnr)
 {
   gdb_assert (gdbarch != NULL);
   gdb_assert (gdbarch->register_name != NULL);
+  gdb_assert (regnr >= 0);
+  gdb_assert (regnr < gdbarch_num_cooked_regs (gdbarch));
   if (gdbarch_debug >= 2)
     gdb_printf (gdb_stdlog, "gdbarch_register_name called\n");
-  return gdbarch->register_name (gdbarch, regnr);
+  auto result = gdbarch->register_name (gdbarch, regnr);
+  gdb_assert (result != nullptr);
+  return result;
 }
 
 void