This is the mail archive of the
gdb-patches@sources.redhat.com
mailing list for the GDB project.
[RFC] fixing extract_struct_value_address
- From: Michael Snyder <msnyder at redhat dot com>
- To: gdb-patches at sources dot redhat dot com
- Cc: kevinb at redhat dot com, cagney at redhat dot com
- Date: Wed, 21 Aug 2002 15:48:37 -0700
- Subject: [RFC] fixing extract_struct_value_address
- Organization: Red Hat, Inc.
Problem: Find a function's return value when it is a struct
returned by reference (thru a pointer).
Solution level one: Take the value of the register that was
used by the caller to pass the struct return address.
Shortcoming: that register isn't preserved, so may be clobbered.
Solution level two: Save the struct_return address when it
is passed to store_struct_return (or push_arguments), and
recover it when it is needed by extract_struct_value_address.
Shortcoming: Not reentrant. Nested function calls will clobber it.
Proposed solution: create a stack structure, and "push" the
struct_return address in store_struct_return, popping it in
extract_return_address. If you can't find it on the stack,
then use the value of the appropriate arg0 register.
I think this should work for most targets, so the code for
managing the stack can be shared.
What do you think?