btrace: change branch trace data structure

btrace: change branch trace data structure

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.