782d47dfbd
Doing "info frame" in the outermost frame, when that was indicated by the next frame saying the unwound PC is undefined/not saved, results in error and incomplete output: (gdb) bt #0 thread_function0 (arg=0x0) at threads.c:63 #1 0x00000034cf407d14 in start_thread (arg=0x7ffff7fcb700) at pthread_create.c:309 #2 0x000000323d4f168d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:115 (gdb) frame 2 #2 0x000000323d4f168d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:115 115 call *%rax (gdb) info frame Stack level 2, frame at 0x0: rip = 0x323d4f168d in clone (../sysdeps/unix/sysv/linux/x86_64/clone.S:115); saved rip Register 16 was not saved (gdb) Not saved register values are treated as optimized out values internally throughout. stack.c:frame_info is handing unvailable values, but not optimized out ones. The patch deletes the frame_unwind_caller_pc_if_available wrapper function and instead lets errors propagate to frame_info (it's only user). As frame_unwind_pc now needs to be able to handle and cache two different error scenarios, the prev_pc.p variable is replaced with an enumeration. (FWIW, I looked into making gdbarch_unwind_pc or a variant return struct value's instead, but it results in lots of boxing and unboxing for no real gain -- e.g., the mips and arm implementations need to do computation on the unboxed PC value. Might as well throw an error on first attempt to get at invalid contents.) After the patch, we get: (gdb) info frame Stack level 2, frame at 0x0: rip = 0x323d4f168d in clone (../sysdeps/unix/sysv/linux/x86_64/clone.S:115); saved rip = <not saved> Outermost frame: outermost caller of frame at 0x7ffff7fcafc0 source language asm. Arglist at 0x7ffff7fcafb8, args: Locals at 0x7ffff7fcafb8, Previous frame's sp is 0x7ffff7fcafc8 (gdb) A new test is added. It's based off dw2-reg-undefined.exp, and tweaked to mark the return address (rip) of "stop_frame" as undefined. Tested on x86_64 Fedora 17. gdb/ 2013-12-06 Pedro Alves <palves@redhat.com> * frame.c (enum cached_copy_status): New enum. (struct frame_info) <prev_pc.p>: Change type to enum cached_copy_status. (fprint_frame): Handle not saved and unavailable prev_pc values. (frame_unwind_pc_if_available): Delete and merge contents into ... (frame_unwind_pc): ... here. Handle OPTIMIZED_OUT_ERROR. Adjust to use enum cached_copy_status. (frame_unwind_caller_pc_if_available): Delete. (create_new_frame): Adjust. * frame.h (frame_unwind_caller_pc_if_available): Delete declaration. * stack.c (frame_info): Use frame_unwind_caller_pc instead of frame_unwind_caller_pc_if_available, and handle NOT_AVAILABLE_ERROR and OPTIMIZED_OUT_ERROR errors. * valprint.c (val_print_optimized_out): Use val_print_not_saved. (val_print_not_saved): New function. * valprint.h (val_print_not_saved): Declare. gdb/testsuite/ 2013-12-06 Pedro Alves <palves@redhat.com> * gdb.dwarf2/dw2-undefined-ret-addr.S: New file. * gdb.dwarf2/dw2-undefined-ret-addr.c: New file. * gdb.dwarf2/dw2-undefined-ret-addr.exp: New file.
36 lines
946 B
C
36 lines
946 B
C
/*
|
|
Copyright 2013 Free Software Foundation, Inc.
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>. */
|
|
|
|
void
|
|
stop_frame ()
|
|
{
|
|
/* The debug information for this frame is modified in the accompanying
|
|
.S file, to mark the return address as undefined. */
|
|
}
|
|
|
|
void
|
|
first_frame ()
|
|
{
|
|
stop_frame ();
|
|
}
|
|
|
|
int
|
|
main ()
|
|
{
|
|
first_frame ();
|
|
|
|
return 0;
|
|
}
|