------- Comment #3 from hutchinsonandy at aim dot com 2008-03-29 12:55 ------- Created an attachment (id=15396) --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=15396&action=view) Patch to correct return_address
The attached patch fixes this problem and PR21078 The AVR target support for builtin_return_address only returned value of frame_pointer+1 - so it would only be correct if stack and frame were empty. The attached patch calculates the stack usage in the function prolog. This is placed in symbol stack_usage using UNSPEC instruction pattern. Builtin Return address uses RETURN_ADDR_RTX(count, tem) to add this to frame pointer to get to correct address. This only supports level 0 (same function). Other levels (ie upper functions) return 0 - which is correct response if not supported. The address is that read from the stack - ie word address. Testsuite torture/execute/20010122-1.c and PR17377.c both pass with this patch applied. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21080
