Provide to_resume and to_wait target methods for the btrace record target
to allow reverse stepping and replay support.
Replay is limited in the sense that only stepping and source correlation
are supported. We do not record data and thus can not show variables.
Non-stop mode is not working. Do not allow record-btrace in non-stop mode.
2014-01-16 Markus Metzger <markus.t.metzger@intel.com>
* btrace.h (btrace_thread_flag): New.
(struct btrace_thread_info) <flags>: New.
* record-btrace.c (record_btrace_resume_thread)
(record_btrace_find_thread_to_move, btrace_step_no_history)
(btrace_step_stopped, record_btrace_start_replaying)
(record_btrace_step_thread, record_btrace_decr_pc_after_break)
(record_btrace_find_resume_thread): New.
(record_btrace_resume, record_btrace_wait): Extend.
(record_btrace_can_execute_reverse): New.
(record_btrace_open): Fail in non-stop mode.
(record_btrace_set_replay): Split into this, ...
(record_btrace_stop_replaying): ... this, ...
(record_btrace_clear_histories): ... and this.
(init_record_btrace_ops): Init to_can_execute_reverse.
* NEWS: Announce it.
testsuite/
* gdb.btrace/delta.exp: Check reverse stepi.
* gdb.btrace/tailcall.exp: Update. Add stepping tests.
* gdb.btrace/finish.exp: New.
* gdb.btrace/next.exp: New.
* gdb.btrace/nexti.exp: New.
* gdb.btrace/record_goto.c: Add comments.
* gdb.btrace/step.exp: New.
* gdb.btrace/stepi.exp: New.
* gdb.btrace/multi-thread-step.c: New.
* gdb.btrace/multi-thread-step.exp: New.
* gdb.btrace/rn-dl-bind.c: New.
* gdb.btrace/rn-dl-bind.exp: New.
* gdb.btrace/data.c: New.
* gdb.btrace/data.exp: New.
* gdb.btrace/Makefile.in (EXECUTABLES): Add new.
doc/
* gdb.texinfo: Document limited reverse/replay support
for target record-btrace.
The btrace record target shows the branch trace from the location of the first
branch destination. This is the first BTS records.
After adding incremental updates, we can now add a dummy record for the current
PC when we enable tracing so we show the trace from the location where branch
tracing has been enabled.
2014-01-16 Markus Metzger <markus.t.metzger@intel.com>
* btrace.c: Include regcache.h.
(btrace_add_pc): New.
(btrace_enable): Call btrace_add_pc.
(btrace_is_empty): New.
* btrace.h (btrace_is_empty): New.
* record-btrace.c (require_btrace, record_btrace_info): Call
btrace_is_empty.
testsuite/
* gdb.btrace/Makefile.in (EXECUTABLES): Add delta.
* gdb.btrace/exception.exp: Update.
* gdb.btrace/instruction_history.exp: Update.
* gdb.btrace/record_goto.exp: Update.
* gdb.btrace/tailcall.exp: Update.
* gdb.btrace/unknown_functions.exp: Update.
* gdb.btrace/delta.exp: New.
Add a branch trace instruction iterator pointing to the current replay position
to the branch trace thread info struct.
Free the iterator when btrace is cleared.
Start at the replay position for the instruction and function-call histories.
2014-01-16 Markus Metzger <markus.t.metzger@intel.com>
* btrace.h (replay) <replay>: New.
(btrace_is_replaying): New.
* btrace.c (btrace_clear): Free replay iterator.
(btrace_is_replaying): New.
* record-btrace.c (record_btrace_is_replaying): New.
(record_btrace_info): Print insn number if replaying.
(record_btrace_insn_history): Start at replay position.
(record_btrace_call_history): Start at replay position.
(init_record_btrace_ops): Init to_record_is_replaying.
The branch trace is represented as 3 vectors:
- a block vector
- a instruction vector
- a function vector
Each vector (except for the first) is computed from the one above.
Change this into a graph where a node represents a sequence of instructions
belonging to the same function and where we have three types of edges to connect
the function segments:
- control flow
- same function (instance)
- call stack
This allows us to navigate in the branch trace. We will need this for "record
goto" and reverse execution.
This patch introduces the data structure and computes the control flow edges.
It also introduces iterator structs to simplify iterating over the branch trace
in control-flow order.
It also fixes PR gdb/15240 since now recursive calls are handled correctly.
Fix the test that got the number of expected fib instances and also the
function numbers wrong.
The current instruction had been part of the branch trace. This will look odd
once we start support for reverse execution. Remove it. We still keep it in
the trace itself to allow extending the branch trace more easily in the future.
2014-01-16 Markus Metzger <markus.t.metzger@intel.com>
* btrace.h (struct btrace_func_link): New.
(enum btrace_function_flag): New.
(struct btrace_inst): Rename to ...
(struct btrace_insn): ...this. Update all users.
(struct btrace_func) <ibegin, iend>: Remove.
(struct btrace_func_link): New.
(struct btrace_func): Rename to ...
(struct btrace_function): ...this. Update all users.
(struct btrace_function) <segment, flow, up, insn, insn_offset)
(number, level, flags>: New.
(struct btrace_insn_iterator): Rename to ...
(struct btrace_insn_history): ...this.
Update all users.
(struct btrace_insn_iterator, btrace_call_iterator): New.
(struct btrace_target_info) <btrace, itrace, ftrace>: Remove.
(struct btrace_target_info) <begin, end, level>
<insn_history, call_history>: New.
(btrace_insn_get, btrace_insn_number, btrace_insn_begin)
(btrace_insn_end, btrace_insn_prev, btrace_insn_next)
(btrace_insn_cmp, btrace_find_insn_by_number, btrace_call_get)
(btrace_call_number, btrace_call_begin, btrace_call_end)
(btrace_call_prev, btrace_call_next, btrace_call_cmp)
(btrace_find_function_by_number, btrace_set_insn_history)
(btrace_set_call_history): New.
* btrace.c (btrace_init_insn_iterator)
(btrace_init_func_iterator, compute_itrace): Remove.
(ftrace_print_function_name, ftrace_print_filename)
(ftrace_skip_file): Change
parameter to const.
(ftrace_init_func): Remove.
(ftrace_debug): Use new btrace_function fields.
(ftrace_function_switched): Also consider gaining and
losing symbol information).
(ftrace_print_insn_addr, ftrace_new_call, ftrace_new_return)
(ftrace_new_switch, ftrace_find_caller, ftrace_new_function)
(ftrace_update_caller, ftrace_fixup_caller, ftrace_new_tailcall):
New.
(ftrace_new_function): Move. Remove debug print.
(ftrace_update_lines, ftrace_update_insns): New.
(ftrace_update_function): Check for call, ret, and jump.
(compute_ftrace): Renamed to ...
(btrace_compute_ftrace): ...this. Rewritten to compute call
stack.
(btrace_fetch, btrace_clear): Updated.
(btrace_insn_get, btrace_insn_number, btrace_insn_begin)
(btrace_insn_end, btrace_insn_prev, btrace_insn_next)
(btrace_insn_cmp, btrace_find_insn_by_number, btrace_call_get)
(btrace_call_number, btrace_call_begin, btrace_call_end)
(btrace_call_prev, btrace_call_next, btrace_call_cmp)
(btrace_find_function_by_number, btrace_set_insn_history)
(btrace_set_call_history): New.
* record-btrace.c (require_btrace): Use new btrace thread
info fields.
(record_btrace_info, btrace_insn_history)
(record_btrace_insn_history, record_btrace_insn_history_range):
Use new btrace thread info fields and new iterator.
(btrace_func_history_src_line): Rename to ...
(btrace_call_history_src_line): ...this. Use new btrace
thread info fields.
(btrace_func_history): Rename to ...
(btrace_call_history): ...this. Use new btrace thread info
fields and new iterator.
(record_btrace_call_history, record_btrace_call_history_range):
Use new btrace thread info fields and new iterator.
testsuite/
* gdb.btrace/function_call_history.exp: Fix expected function
trace.
* gdb.btrace/instruction_history.exp: Initialize traced.
Remove traced_functions.
Add a function to parse a btrace xml document into a vector of branch trace
blocks.
gdb/
* features/btrace.dtd: New file.
* Makefile.in (XMLFILES): Add btrace.dtd.
* btrace.h (parse_xml_btrace): New declaration.
* btrace.c: Include xml-support.h.
(parse_xml_btrace): New function.
(parse_xml_btrace_block): New function.
(block_attributes): New struct.
(btrace_attributes): New struct.
(btrace_children): New struct.
(btrace_elements): New struct.
