From fe67a58f98232db44e620cd2bb450fca47635104 Mon Sep 17 00:00:00 2001 From: Simon Marchi Date: Tue, 29 Jun 2021 12:05:14 -0400 Subject: gdb: introduce FRAME_SCOPED_DEBUG_ENTER_EXIT Introduce FRAME_SCOPED_DEBUG_ENTER_EXIT and use it to print enter/exit messages in important frame-related functions. I think this helps understand which lower-level operations are done as part of which higher-level operation. And it helps visually skip over a higher-level operation you are not interested in. Here's an example, combined with some py-unwind messages: [frame] frame_unwind_find_by_frame: enter [frame] frame_unwind_find_by_frame: this_frame=0 [frame] frame_unwind_try_unwinder: trying unwinder "dummy" [frame] frame_unwind_try_unwinder: no [frame] frame_unwind_try_unwinder: trying unwinder "dwarf2 tailcall" [frame] frame_unwind_try_unwinder: no [frame] frame_unwind_try_unwinder: trying unwinder "inline" [frame] frame_unwind_try_unwinder: no [frame] frame_unwind_try_unwinder: trying unwinder "jit" [frame] frame_unwind_try_unwinder: no [frame] frame_unwind_try_unwinder: trying unwinder "python" [py-unwind] pyuw_sniffer: enter [frame] frame_unwind_register_value: enter [frame] frame_unwind_register_value: frame=-1, regnum=7(rsp) [frame] frame_unwind_register_value: -> register=7 bytes=[40ddffffff7f0000] [frame] frame_unwind_register_value: exit [py-unwind] pyuw_sniffer: frame=0, sp=0x7fffffffdd40, pc=0x5555555551ec [frame] frame_id_p: l={stack=,!code,special=0x0000000000000000} -> 1 [frame] frame_id_p: l={stack=,!code,special=0x0000000000000000} -> 1 [frame] frame_id_eq: l={stack=,!code,special=0x0000000000000000}, r={stack=,!code,special=0x0000000000000000} -> 1 [frame] frame_unwind_register_value: enter [frame] frame_unwind_register_value: frame=-1, regnum=6(rbp) [frame] frame_unwind_register_value: -> register=6 bytes=[50ddffffff7f0000] [frame] frame_unwind_register_value: exit [frame] frame_id_p: l={stack=,!code,special=0x0000000000000000} -> 1 [frame] frame_id_eq: l={stack=,!code,special=0x0000000000000000}, r={stack=,!code,special=0x0000000000000000} -> 1 [frame] get_prev_frame: enter [frame] get_prev_frame_always_1: enter [frame] get_prev_frame_always_1: this_frame=-1 [frame] get_prev_frame_always_1: -> {level=0,type=NORMAL_FRAME,unwind=0x5588ee3d17c0,pc=0x5555555551ec,id=,func=} // cached [frame] get_prev_frame_always_1: exit [frame] get_prev_frame: exit [frame] value_fetch_lazy_register: (frame=0, regnum=6(rbp), ...) -> register=6 bytes=[50ddffffff7f0000] [frame] frame_id_p: l={stack=,!code,special=0x0000000000000000} -> 1 [frame] frame_id_p: l={stack=,!code,special=0x0000000000000000} -> 1 [frame] frame_id_eq: l={stack=,!code,special=0x0000000000000000}, r={stack=,!code,special=0x0000000000000000} -> 1 [frame] frame_unwind_register_value: enter [frame] frame_unwind_register_value: frame=-1, regnum=7(rsp) [frame] frame_unwind_register_value: -> register=7 bytes=[40ddffffff7f0000] [frame] frame_unwind_register_value: exit [frame] frame_id_p: l={stack=,!code,special=0x0000000000000000} -> 1 [frame] frame_id_eq: l={stack=,!code,special=0x0000000000000000}, r={stack=,!code,special=0x0000000000000000} -> 1 [frame] get_prev_frame: enter [frame] get_prev_frame_always_1: enter [frame] get_prev_frame_always_1: this_frame=-1 [frame] get_prev_frame_always_1: -> {level=0,type=NORMAL_FRAME,unwind=0x5588ee3d1824,pc=0x5555555551ec,id=,func=} // cached [frame] get_prev_frame_always_1: exit [frame] get_prev_frame: exit [frame] value_fetch_lazy_register: (frame=0, regnum=7(rsp), ...) -> register=7 bytes=[40ddffffff7f0000] [frame] frame_id_p: l={stack=,!code,special=0x0000000000000000} -> 1 [frame] frame_id_p: l={stack=,!code,special=0x0000000000000000} -> 1 [frame] frame_id_eq: l={stack=,!code,special=0x0000000000000000}, r={stack=,!code,special=0x0000000000000000} -> 1 [frame] frame_unwind_register_value: enter [frame] frame_unwind_register_value: frame=-1, regnum=16(rip) [frame] frame_unwind_register_value: -> register=16 bytes=[ec51555555550000] [frame] frame_unwind_register_value: exit [frame] frame_id_p: l={stack=,!code,special=0x0000000000000000} -> 1 [frame] frame_id_eq: l={stack=,!code,special=0x0000000000000000}, r={stack=,!code,special=0x0000000000000000} -> 1 [frame] get_prev_frame: enter [frame] get_prev_frame_always_1: enter [frame] get_prev_frame_always_1: this_frame=-1 [frame] get_prev_frame_always_1: -> {level=0,type=NORMAL_FRAME,unwind=0x5588ee3d1888,pc=0x5555555551ec,id=,func=} // cached [frame] get_prev_frame_always_1: exit [frame] get_prev_frame: exit [frame] value_fetch_lazy_register: (frame=0, regnum=16(rip), ...) -> register=16 bytes=[ec51555555550000] [py-unwind] pyuw_sniffer: frame claimed by unwinder test unwinder [py-unwind] pyuw_sniffer: exit [frame] frame_unwind_try_unwinder: yes [frame] frame_unwind_find_by_frame: exit gdb/ChangeLog: * frame.h (FRAME_SCOPED_DEBUG_ENTER_EXIT): New. * frame.c (compute_frame_id, get_prev_frame_always_1, get_prev_frame): Use FRAME_SCOPED_DEBUG_ENTER_EXIT. * frame-unwind.c (frame_unwind_find_by_frame): Likewise. (frame_unwind_register_value): Likewise. Change-Id: I45b69b4ed962e70572bc55b8adfb211483c1eeed --- gdb/frame.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) (limited to 'gdb/frame.c') diff --git a/gdb/frame.c b/gdb/frame.c index 7b45968..3f2d270 100644 --- a/gdb/frame.c +++ b/gdb/frame.c @@ -560,6 +560,8 @@ skip_tailcall_frames (struct frame_info *frame) static void compute_frame_id (struct frame_info *fi) { + FRAME_SCOPED_DEBUG_ENTER_EXIT; + gdb_assert (fi->this_id.p == frame_id_status::NOT_COMPUTED); unsigned int entry_generation = get_frame_cache_generation (); @@ -1215,12 +1217,10 @@ get_frame_register (struct frame_info *frame, struct value * frame_unwind_register_value (frame_info *next_frame, int regnum) { - struct gdbarch *gdbarch; - struct value *value; + FRAME_SCOPED_DEBUG_ENTER_EXIT; gdb_assert (next_frame != NULL); - gdbarch = frame_unwind_arch (next_frame); - + gdbarch *gdbarch = frame_unwind_arch (next_frame); frame_debug_printf ("frame=%d, regnum=%d(%s)", next_frame->level, regnum, user_reg_map_regnum_to_name (gdbarch, regnum)); @@ -1230,9 +1230,9 @@ frame_unwind_register_value (frame_info *next_frame, int regnum) frame_unwind_find_by_frame (next_frame, &next_frame->prologue_cache); /* Ask this frame to unwind its register. */ - value = next_frame->unwind->prev_register (next_frame, - &next_frame->prologue_cache, - regnum); + value *value = next_frame->unwind->prev_register (next_frame, + &next_frame->prologue_cache, + regnum); if (frame_debug) { @@ -2104,10 +2104,9 @@ get_prev_frame_if_no_cycle (struct frame_info *this_frame) static struct frame_info * get_prev_frame_always_1 (struct frame_info *this_frame) { - struct gdbarch *gdbarch; + FRAME_SCOPED_DEBUG_ENTER_EXIT; gdb_assert (this_frame != NULL); - gdbarch = get_frame_arch (this_frame); if (frame_debug) { @@ -2117,6 +2116,8 @@ get_prev_frame_always_1 (struct frame_info *this_frame) frame_debug_printf ("this_frame=nullptr"); } + struct gdbarch *gdbarch = get_frame_arch (this_frame); + /* Only try to do the unwind once. */ if (this_frame->prev_p) { @@ -2419,6 +2420,8 @@ inside_entry_func (frame_info *this_frame) struct frame_info * get_prev_frame (struct frame_info *this_frame) { + FRAME_SCOPED_DEBUG_ENTER_EXIT; + CORE_ADDR frame_pc; int frame_pc_p; -- cgit v1.1