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Re: RFA/dwarf: Fix the GCC 2.95.3 store.exp regression for multi-register variables
- From: Michael Elizabeth Chastain <mec at shout dot net>
- To: drow at mvista dot com, ezannoni at redhat dot com
- Cc: gdb-patches at sources dot redhat dot com
- Date: Fri, 4 Apr 2003 00:41:58 -0600
- Subject: Re: RFA/dwarf: Fix the GCC 2.95.3 store.exp regression for multi-register variables
My test bed says that this is okay. It fixes the regression in
store.exp with gcc 2.95.3 -gdwarf-2 (gcc 2.95.3 is the only compiler
that puts this particular struct into a register). And it doesn't
have any regressions with any gcc v2 or v3, dwarf-2 or stabs+,
on my native i686-pc-linux-gnu.
I have another PR for this, gdb/1107, that comes with a source file
and an executable file. With this patch, gdb HEAD changes from
'new bad behavior' back to 'same bad behavior as 5.3'. Specifically,
I have a structure which is in %ebx and %esi. gdb 5.3 prints values
from %ebx and %esp (the next register in 'info registers').
gdb HEAD prints %ebx and something from god knows where, and
gdb HEAD + patch prints %ebx and %esp again.
(I really hate it when gdb prints the wrong numbers!)
With this patch gdb is better in the store.exp case and not any
worse in the gdb/1107 case. What the heck, here's a table:
gdb 5.3 okay wrong
gdb HEAD wrong wrong
gdb HEAD + drow okay wrong
So ... recommended for approval. If it goes in then we can maybe talk
about gdb/1107 some more.
2003-03-12 Daniel Jacobowitz <drow at mvista dot com>
* dwarf2expr.h (struct dwarf_expr_context): Remove extra arguments
to read_reg and update its comment. Remove regnum member.
* dwarf2expr.c (execute_stack_op): Remove memaddr and expr_lval.
Don't call read_reg when setting in_reg. Call read_reg to get
the frame base if it's in a register. Return the register number
on the stack instead of in the context. Remove extra arguments
* dwarf2loc.c (dwarf_expr_read_reg): Remove extra arguments.
(dwarf2_evaluate_loc_desc): Call value_from_register. Expect
the register number on the expression stack.
(needs_frame_read_reg): Remove extra arguments.