[patch v8 06/24] btrace: change branch trace data structure

Markus Metzger
2013-12-12T09:16:15Z

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.

CC: Christian Himpel <christian.himpel@intel.com>
2013-12-12 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.

---
gdb/btrace.c | 1151 ++++++++++++++++----
gdb/btrace.h | 237 +++-
gdb/record-btrace.c | 342 +++---
gdb/testsuite/gdb.btrace/function_call_history.exp | 28 +-
gdb/testsuite/gdb.btrace/instruction_history.exp | 14 +-
5 files changed, 1374 insertions(+), 398 deletions(-)

diff --git a/gdb/btrace.c b/gdb/btrace.c
index 46e73db..975b60c 100644
--- a/gdb/btrace.c
+++ b/gdb/btrace.c
@@ -45,92 +45,11 @@

#define DEBUG_FTRACE(msg, args...) DEBUG ("[ftrace] " msg, ##args)

-/* Initialize the instruction iterator. */
-
-static void
-btrace_init_insn_iterator (struct btrace_thread_info *btinfo)
-{
- DEBUG ("init insn iterator");
-
- btinfo->insn_iterator.begin = 1;
- btinfo->insn_iterator.end = 0;
-}
-
-/* Initialize the function iterator. */
-
-static void
-btrace_init_func_iterator (struct btrace_thread_info *btinfo)
-{
- DEBUG ("init func iterator");
-
- btinfo->func_iterator.begin = 1;
- btinfo->func_iterator.end = 0;
-}
-
-/* Compute the instruction trace from the block trace. */
-
-static VEC (btrace_inst_s) *
-compute_itrace (VEC (btrace_block_s) *btrace)
-{
- VEC (btrace_inst_s) *itrace;
- struct gdbarch *gdbarch;
- unsigned int b;
-
- DEBUG ("compute itrace");
-
- itrace = NULL;
- gdbarch = target_gdbarch ();
- b = VEC_length (btrace_block_s, btrace);
-
- while (b-- != 0)
- {
- btrace_block_s *block;
- CORE_ADDR pc;
-
- block = VEC_index (btrace_block_s, btrace, b);
- pc = block->begin;
-
- /* Add instructions for this block. */
- for (;;)
- {
- btrace_inst_s *inst;
- int size;
-
- /* We should hit the end of the block. Warn if we went too far. */
- if (block->end < pc)
- {
- warning (_("Recorded trace may be corrupted."));
- break;
- }
-
- inst = VEC_safe_push (btrace_inst_s, itrace, NULL);
- inst->pc = pc;
-
- /* We're done once we pushed the instruction at the end. */
- if (block->end == pc)
- break;
-
- size = gdb_insn_length (gdbarch, pc);
-
- /* Make sure we terminate if we fail to compute the size. */
- if (size <= 0)
- {
- warning (_("Recorded trace may be incomplete."));
- break;
- }
-
- pc += size;
- }
- }
-
- return itrace;
-}
-
/* Return the function name of a recorded function segment for printing.
This function never returns NULL. */

static const char *
-ftrace_print_function_name (struct btrace_func *bfun)
+ftrace_print_function_name (const struct btrace_function *bfun)
{
struct minimal_symbol *msym;
struct symbol *sym;
@@ -151,7 +70,7 @@ ftrace_print_function_name (struct btrace_func *bfun)
This function never returns NULL. */

static const char *
-ftrace_print_filename (struct btrace_func *bfun)
+ftrace_print_filename (const struct btrace_function *bfun)
{
struct symbol *sym;
const char *filename;
@@ -166,44 +85,53 @@ ftrace_print_filename (struct btrace_func *bfun)
return filename;
}

-/* Print an ftrace debug status message. */
+/* Return a string representation of the address of an instruction.
+ This function never returns NULL. */

-static void
-ftrace_debug (struct btrace_func *bfun, const char *prefix)
+static const char *
+ftrace_print_insn_addr (const struct btrace_insn *insn)
{
- DEBUG_FTRACE ("%s: fun = %s, file = %s, lines = [%d; %d], insn = [%u; %u]",
- prefix, ftrace_print_function_name (bfun),
- ftrace_print_filename (bfun), bfun->lbegin, bfun->lend,
- bfun->ibegin, bfun->iend);
+ if (insn == NULL)
+ return "<nil>";
+
+ return core_addr_to_string_nz (insn->pc);
}

-/* Initialize a recorded function segment. */
+/* Print an ftrace debug status message. */

static void
-ftrace_init_func (struct btrace_func *bfun, struct minimal_symbol *mfun,
- struct symbol *fun, unsigned int idx)
+ftrace_debug (const struct btrace_function *bfun, const char *prefix)
{
- bfun->msym = mfun;
- bfun->sym = fun;
- bfun->lbegin = INT_MAX;
- bfun->lend = 0;
- bfun->ibegin = idx;
- bfun->iend = idx;
+ const char *fun, *file;
+ unsigned int ibegin, iend;
+ int lbegin, lend, level;
+
+ fun = ftrace_print_function_name (bfun);
+ file = ftrace_print_filename (bfun);
+ level = bfun->level;
+
+ lbegin = bfun->lbegin;
+ lend = bfun->lend;
+
+ ibegin = bfun->insn_offset;
+ iend = ibegin + VEC_length (btrace_insn_s, bfun->insn);
+
+ DEBUG_FTRACE ("%s: fun = %s, file = %s, level = %d, lines = [%d; %d], "
+ "insn = [%u; %u)", prefix, fun, file, level, lbegin, lend,
+ ibegin, iend);
}

-/* Check whether the function has changed. */
+/* Return non-zero if BFUN does not match MFUN and FUN,
+ return zero otherwise. */

static int
-ftrace_function_switched (struct btrace_func *bfun,
- struct minimal_symbol *mfun, struct symbol *fun)
+ftrace_function_switched (const struct btrace_function *bfun,
+ const struct minimal_symbol *mfun,
+ const struct symbol *fun)
{
struct minimal_symbol *msym;
struct symbol *sym;

- /* The function changed if we did not have one before. */
- if (bfun == NULL)
- return 1;
-
msym = bfun->msym;
sym = bfun->sym;

@@ -228,109 +156,505 @@ ftrace_function_switched (struct btrace_func *bfun,
return 1;
}

+ /* If we lost symbol information, we switched functions. */
+ if (!(msym == NULL && sym == NULL) && mfun == NULL && fun == NULL)
+ return 1;
+
+ /* If we gained symbol information, we switched functions. */
+ if (msym == NULL && sym == NULL && !(mfun == NULL && fun == NULL))
+ return 1;
+
return 0;
}

-/* Check if we should skip this file when generating the function call
- history. We would want to do that if, say, a macro that is defined
- in another file is expanded in this function. */
+/* Return non-zero if we should skip this file when generating the function
+ call history, zero otherwise.
+ We would want to do that if, say, a macro that is defined in another file
+ is expanded in this function. */

static int
-ftrace_skip_file (struct btrace_func *bfun, const char *filename)
+ftrace_skip_file (const struct btrace_function *bfun, const char *fullname)
{
struct symbol *sym;
const char *bfile;

sym = bfun->sym;
+ if (sym == NULL)
+ return 1;

- if (sym != NULL)
- bfile = symtab_to_fullname (sym->symtab);
- else
- bfile = "";
+ bfile = symtab_to_fullname (sym->symtab);
+
+ return (filename_cmp (bfile, fullname) != 0);
+}
+
+/* Allocate and initialize a new branch trace function segment.
+ PREV is the chronologically preceding function segment.
+ MFUN and FUN are the symbol information we have for this function. */
+
+static struct btrace_function *
+ftrace_new_function (struct btrace_function *prev,
+ struct minimal_symbol *mfun,
+ struct symbol *fun)
+{
+ struct btrace_function *bfun;
+
+ bfun = xzalloc (sizeof (*bfun));
+
+ bfun->msym = mfun;
+ bfun->sym = fun;
+ bfun->flow.prev = prev;
+
+ /* We start with the identities of min and max, respectively. */
+ bfun->lbegin = INT_MAX;
+ bfun->lend = INT_MIN;

- if (filename == NULL)
- filename = "";
+ if (prev != NULL)
+ {
+ gdb_assert (prev->flow.next == NULL);
+ prev->flow.next = bfun;

- return (filename_cmp (bfile, filename) != 0);
+ bfun->number = prev->number + 1;
+ bfun->insn_offset = (prev->insn_offset
+ + VEC_length (btrace_insn_s, prev->insn));
+ }
+
+ return bfun;
}

-/* Compute the function trace from the instruction trace. */
+/* Update the UP field of a function segment. */

-static VEC (btrace_func_s) *
-compute_ftrace (VEC (btrace_inst_s) *itrace)
+static void
+ftrace_update_caller (struct btrace_function *bfun,
+ struct btrace_function *caller,
+ enum btrace_function_flag flags)
{
- VEC (btrace_func_s) *ftrace;
- struct btrace_inst *binst;
- struct btrace_func *bfun;
- unsigned int idx;
+ if (bfun->up != NULL)
+ ftrace_debug (bfun, "updating caller");

- DEBUG ("compute ftrace");
+ bfun->up = caller;
+ bfun->flags = flags;
+
+ ftrace_debug (bfun, "set caller");
+}
+
+/* Fix up the caller for all segments of a function. */
+
+static void
+ftrace_fixup_caller (struct btrace_function *bfun,
+ struct btrace_function *caller,
+ enum btrace_function_flag flags)
+{
+ struct btrace_function *prev, *next;
+
+ ftrace_update_caller (bfun, caller, flags);
+
+ /* Update all function segments belonging to the same function. */
+ for (prev = bfun->segment.prev; prev != NULL; prev = prev->segment.prev)
+ ftrace_update_caller (prev, caller, flags);
+
+ for (next = bfun->segment.next; next != NULL; next = next->segment.next)
+ ftrace_update_caller (next, caller, flags);
+}
+
+/* Add a new function segment for a call.
+ CALLER is the chronologically preceding function segment.
+ MFUN and FUN are the symbol information we have for this function. */
+
+static struct btrace_function *
+ftrace_new_call (struct btrace_function *caller,
+ struct minimal_symbol *mfun,
+ struct symbol *fun)
+{
+ struct btrace_function *bfun;
+
+ bfun = ftrace_new_function (caller, mfun, fun);
+ bfun->up = caller;
+ bfun->level = caller->level + 1;
+
+ ftrace_debug (bfun, "new call");
+
+ return bfun;
+}
+
+/* Add a new function segment for a tail call.
+ CALLER is the chronologically preceding function segment.
+ MFUN and FUN are the symbol information we have for this function. */
+
+static struct btrace_function *
+ftrace_new_tailcall (struct btrace_function *caller,
+ struct minimal_symbol *mfun,
+ struct symbol *fun)
+{
+ struct btrace_function *bfun;

- ftrace = NULL;
- bfun = NULL;
+ bfun = ftrace_new_function (caller, mfun, fun);
+ bfun->up = caller;
+ bfun->level = caller->level + 1;
+ bfun->flags |= BFUN_UP_LINKS_TO_TAILCALL;

- for (idx = 0; VEC_iterate (btrace_inst_s, itrace, idx, binst); ++idx)
+ ftrace_debug (bfun, "new tail call");
+
+ return bfun;
+}
+
+/* Find the innermost caller in the back trace of BFUN with MFUN/FUN
+ symbol information. */
+
+static struct btrace_function *
+ftrace_find_caller (struct btrace_function *bfun,
+ struct minimal_symbol *mfun,
+ struct symbol *fun)
+{
+ for (; bfun != NULL; bfun = bfun->up)
+ {
+ /* Skip functions with incompatible symbol information. */
+ if (ftrace_function_switched (bfun, mfun, fun))
+ continue;
+
+ /* This is the function segment we're looking for. */
+ break;
+ }
+
+ return bfun;
+}
+
+/* Find the innermost caller in the back trace of BFUN, skipping all
+ function segments that do not end with a call instruction (e.g.
+ tail calls ending with a jump). */
+
+static struct btrace_function *
+ftrace_find_call (struct gdbarch *gdbarch, struct btrace_function *bfun)
+{
+ for (; bfun != NULL; bfun = bfun->up)
{
- struct symtab_and_line sal;
- struct bound_minimal_symbol mfun;
- struct symbol *fun;
- const char *filename;
+ struct btrace_insn *last;
CORE_ADDR pc;

- pc = binst->pc;
+ /* We do not allow empty function segments. */
+ gdb_assert (!VEC_empty (btrace_insn_s, bfun->insn));
+
+ last = VEC_last (btrace_insn_s, bfun->insn);
+ pc = last->pc;

- /* Try to determine the function we're in. We use both types of symbols
- to avoid surprises when we sometimes get a full symbol and sometimes
- only a minimal symbol. */
- fun = find_pc_function (pc);
- mfun = lookup_minimal_symbol_by_pc (pc);
+ if (gdbarch_insn_is_call (gdbarch, pc))
+ break;
+ }
+
+ return bfun;
+}
+
+/* Add a continuation segment for a function into which we return.
+ PREV is the chronologically preceding function segment.
+ MFUN and FUN are the symbol information we have for this function. */
+
+static struct btrace_function *
+ftrace_new_return (struct gdbarch *gdbarch,
+ struct btrace_function *prev,
+ struct minimal_symbol *mfun,
+ struct symbol *fun)
+{
+ struct btrace_function *bfun, *caller;
+
+ bfun = ftrace_new_function (prev, mfun, fun);
+
+ /* It is important to start at PREV's caller. Otherwise, we might find
+ PREV itself, if PREV is a recursive function. */
+ caller = ftrace_find_caller (prev->up, mfun, fun);
+ if (caller != NULL)
+ {
+ /* The caller of PREV is the preceding btrace function segment in this
+ function instance. */
+ gdb_assert (caller->segment.next == NULL);
+
+ caller->segment.next = bfun;
+ bfun->segment.prev = caller;
+
+ /* Maintain the function level. */
+ bfun->level = caller->level;
+
+ /* Maintain the call stack. */
+ bfun->up = caller->up;
+ bfun->flags = caller->flags;
+
+ ftrace_debug (bfun, "new return");
+ }
+ else
+ {
+ /* We did not find a caller. This could mean that something went
+ wrong or that the call is simply not included in the trace. */

- if (fun == NULL && mfun.minsym == NULL)
+ /* Let's search for some actual call. */
+ caller = ftrace_find_call (gdbarch, prev->up);
+ if (caller == NULL)
{
- DEBUG_FTRACE ("no symbol at %u, pc=%s", idx,
- core_addr_to_string_nz (pc));
- continue;
- }
+ /* There is no call in PREV's back trace. We assume that the
+ branch trace did not include it. */
+
+ /* Let's find the topmost call function - this skips tail calls. */
+ while (prev->up != NULL)
+ prev = prev->up;

- /* If we're switching functions, we start over. */
- if (ftrace_function_switched (bfun, mfun.minsym, fun))
+ /* We maintain levels for a series of returns for which we have
+ not seen the calls.
+ We start at the preceding function's level in case this has
+ already been a return for which we have not seen the call.
+ We start at level 0 otherwise, to handle tail calls correctly. */
+ bfun->level = min (0, prev->level) - 1;
+
+ /* Fix up the call stack for PREV. */
+ ftrace_fixup_caller (prev, bfun, BFUN_UP_LINKS_TO_RET);
+
+ ftrace_debug (bfun, "new return - no caller");
+ }
+ else
{
- bfun = VEC_safe_push (btrace_func_s, ftrace, NULL);
+ /* There is a call in PREV's back trace to which we should have
+ returned. Let's remain at this level. */
+ bfun->level = prev->level;

- ftrace_init_func (bfun, mfun.minsym, fun, idx);
- ftrace_debug (bfun, "init");
+ ftrace_debug (bfun, "new return - unknown caller");
}
+ }
+
+ return bfun;
+}
+
+/* Add a new function segment for a function switch.
+ PREV is the chronologically preceding function segment.
+ MFUN and FUN are the symbol information we have for this function. */
+
+static struct btrace_function *
+ftrace_new_switch (struct btrace_function *prev,
+ struct minimal_symbol *mfun,
+ struct symbol *fun)
+{
+ struct btrace_function *bfun;
+
+ /* This is an unexplained function switch. The call stack will likely
+ be wrong at this point. */
+ bfun = ftrace_new_function (prev, mfun, fun);

- /* Update the instruction range. */
- bfun->iend = idx;
- ftrace_debug (bfun, "update insns");
+ /* We keep the function level. */
+ bfun->level = prev->level;

- /* Let's see if we have source correlation, as well. */
- sal = find_pc_line (pc, 0);
- if (sal.symtab == NULL || sal.line == 0)
+ ftrace_debug (bfun, "new switch");
+
+ return bfun;
+}
+
+/* Update BFUN with respect to the instruction at PC. This may create new
+ function segments.
+ Return the chronologically latest function segment, never NULL. */
+
+static struct btrace_function *
+ftrace_update_function (struct gdbarch *gdbarch,
+ struct btrace_function *bfun, CORE_ADDR pc)
+{
+ struct bound_minimal_symbol bmfun;
+ struct minimal_symbol *mfun;
+ struct symbol *fun;
+ struct btrace_insn *last;
+
+ /* Try to determine the function we're in. We use both types of symbols
+ to avoid surprises when we sometimes get a full symbol and sometimes
+ only a minimal symbol. */
+ fun = find_pc_function (pc);
+ bmfun = lookup_minimal_symbol_by_pc (pc);
+ mfun = bmfun.minsym;
+
+ if (fun == NULL && mfun == NULL)
+ DEBUG_FTRACE ("no symbol at %s", core_addr_to_string_nz (pc));
+
+ /* If we didn't have a function before, we create one. */
+ if (bfun == NULL)
+ return ftrace_new_function (bfun, mfun, fun);
+
+ /* Check the last instruction, if we have one.
+ We do this check first, since it allows us to fill in the call stack
+ links in addition to the normal flow links. */
+ last = NULL;
+ if (!VEC_empty (btrace_insn_s, bfun->insn))
+ last = VEC_last (btrace_insn_s, bfun->insn);
+
+ if (last != NULL)
+ {
+ CORE_ADDR lpc;
+
+ lpc = last->pc;
+
+ /* Check for returns. */
+ if (gdbarch_insn_is_ret (gdbarch, lpc))
+ return ftrace_new_return (gdbarch, bfun, mfun, fun);
+
+ /* Check for calls. */
+ if (gdbarch_insn_is_call (gdbarch, lpc))
{
- DEBUG_FTRACE ("no lines at %u, pc=%s", idx,
- core_addr_to_string_nz (pc));
- continue;
+ int size;
+
+ size = gdb_insn_length (gdbarch, lpc);
+
+ /* Ignore calls to the next instruction. They are used for PIC. */
+ if (lpc + size != pc)
+ return ftrace_new_call (bfun, mfun, fun);
}
+ }
+
+ /* Check if we're switching functions for some other reason. */
+ if (ftrace_function_switched (bfun, mfun, fun))
+ {
+ DEBUG_FTRACE ("switching from %s in %s at %s",
+ ftrace_print_insn_addr (last),
+ ftrace_print_function_name (bfun),
+ ftrace_print_filename (bfun));

- /* Check if we switched files. This could happen if, say, a macro that
- is defined in another file is expanded here. */
- filename = symtab_to_fullname (sal.symtab);
- if (ftrace_skip_file (bfun, filename))
+ if (last != NULL)
{
- DEBUG_FTRACE ("ignoring file at %u, pc=%s, file=%s", idx,
- core_addr_to_string_nz (pc), filename);
- continue;
+ CORE_ADDR start, lpc;
+
+ start = get_pc_function_start (pc);
+
+ /* If we can't determine the function for PC, we treat a jump at
+ the end of the block as tail call. */
+ if (start == 0)
+ start = pc;
+
+ lpc = last->pc;
+
+ /* Jumps indicate optimized tail calls. */
+ if (start == pc && gdbarch_insn_is_jump (gdbarch, lpc))
+ return ftrace_new_tailcall (bfun, mfun, fun);
}

- /* Update the line range. */
- bfun->lbegin = min (bfun->lbegin, sal.line);
- bfun->lend = max (bfun->lend, sal.line);
- ftrace_debug (bfun, "update lines");
+ return ftrace_new_switch (bfun, mfun, fun);
+ }
+
+ return bfun;
+}
+
+/* Update BFUN's source range with respect to the instruction at PC. */
+
+static void
+ftrace_update_lines (struct btrace_function *bfun, CORE_ADDR pc)
+{
+ struct symtab_and_line sal;
+ const char *fullname;
+
+ sal = find_pc_line (pc, 0);
+ if (sal.symtab == NULL || sal.line == 0)
+ {
+ DEBUG_FTRACE ("no lines at %s", core_addr_to_string_nz (pc));
+ return;
+ }
+
+ /* Check if we switched files. This could happen if, say, a macro that
+ is defined in another file is expanded here. */
+ fullname = symtab_to_fullname (sal.symtab);
+ if (ftrace_skip_file (bfun, fullname))
+ {
+ DEBUG_FTRACE ("ignoring file at %s, file=%s",
+ core_addr_to_string_nz (pc), fullname);
+ return;
+ }
+
+ /* Update the line range. */
+ bfun->lbegin = min (bfun->lbegin, sal.line);
+ bfun->lend = max (bfun->lend, sal.line);
+
+ if (record_debug > 1)
+ ftrace_debug (bfun, "update lines");
+}
+
+/* Add the instruction at PC to BFUN's instructions. */
+
+static void
+ftrace_update_insns (struct btrace_function *bfun, CORE_ADDR pc)
+{
+ struct btrace_insn *insn;
+
+ insn = VEC_safe_push (btrace_insn_s, bfun->insn, NULL);
+ insn->pc = pc;
+
+ if (record_debug > 1)
+ ftrace_debug (bfun, "update insn");
+}
+
+/* Compute the function branch trace from a block branch trace BTRACE for
+ a thread given by BTINFO. */
+
+static void
+btrace_compute_ftrace (struct btrace_thread_info *btinfo,
+ VEC (btrace_block_s) *btrace)
+{
+ struct btrace_function *begin, *end;
+ struct gdbarch *gdbarch;
+ unsigned int blk;
+ int level;
+
+ DEBUG ("compute ftrace");
+
+ gdbarch = target_gdbarch ();
+ begin = NULL;
+ end = NULL;
+ level = INT_MAX;
+ blk = VEC_length (btrace_block_s, btrace);
+
+ while (blk != 0)
+ {
+ btrace_block_s *block;
+ CORE_ADDR pc;
+
+ blk -= 1;
+
+ block = VEC_index (btrace_block_s, btrace, blk);
+ pc = block->begin;
+
+ for (;;)
+ {
+ int size;
+
+ /* We should hit the end of the block. Warn if we went too far. */
+ if (block->end < pc)
+ {
+ warning (_("Recorded trace may be corrupted around %s."),
+ core_addr_to_string_nz (pc));
+ break;
+ }
+
+ end = ftrace_update_function (gdbarch, end, pc);
+ if (begin == NULL)
+ begin = end;
+
+ /* Maintain the function level offset. */
+ level = min (level, end->level);
+
+ ftrace_update_insns (end, pc);
+ ftrace_update_lines (end, pc);
+
+ /* We're done once we pushed the instruction at the end. */
+ if (block->end == pc)
+ break;
+
+ size = gdb_insn_length (gdbarch, pc);
+
+ /* Make sure we terminate if we fail to compute the size. */
+ if (size <= 0)
+ {
+ warning (_("Recorded trace may be incomplete around %s."),
+ core_addr_to_string_nz (pc));
+ break;
+ }
+
+ pc += size;
+ }
}

- return ftrace;
+ btinfo->begin = begin;
+ btinfo->end = end;
+
+ /* LEVEL is the minimal function level of all btrace function segments.
+ Define the global level offset to -LEVEL so all function levels are
+ normalized to start at zero. */
+ btinfo->level = -level;
}

/* See btrace.h. */
@@ -394,6 +718,7 @@ btrace_fetch (struct thread_info *tp)
{
struct btrace_thread_info *btinfo;
VEC (btrace_block_s) *btrace;
+ struct cleanup *cleanup;

DEBUG ("fetch thread %d (%s)", tp->num, target_pid_to_str (tp->ptid));

@@ -402,18 +727,15 @@ btrace_fetch (struct thread_info *tp)
return;

btrace = target_read_btrace (btinfo->target, BTRACE_READ_NEW);
- if (VEC_empty (btrace_block_s, btrace))
- return;
-
- btrace_clear (tp);
+ cleanup = make_cleanup (VEC_cleanup (btrace_block_s), &btrace);

- btinfo->btrace = btrace;
- btinfo->itrace = compute_itrace (btinfo->btrace);
- btinfo->ftrace = compute_ftrace (btinfo->itrace);
+ if (!VEC_empty (btrace_block_s, btrace))
+ {
+ btrace_clear (tp);
+ btrace_compute_ftrace (btinfo, btrace);
+ }

- /* Initialize branch trace iterators. */
- btrace_init_insn_iterator (btinfo);
- btrace_init_func_iterator (btinfo);
+ do_cleanups (cleanup);
}

/* See btrace.h. */
@@ -422,18 +744,29 @@ void
btrace_clear (struct thread_info *tp)
{
struct btrace_thread_info *btinfo;
+ struct btrace_function *it, *trash;

DEBUG ("clear thread %d (%s)", tp->num, target_pid_to_str (tp->ptid));

btinfo = &tp->btrace;

- VEC_free (btrace_block_s, btinfo->btrace);
- VEC_free (btrace_inst_s, btinfo->itrace);
- VEC_free (btrace_func_s, btinfo->ftrace);
+ it = btinfo->begin;
+ while (it != NULL)
+ {
+ trash = it;
+ it = it->flow.next;

- btinfo->btrace = NULL;
- btinfo->itrace = NULL;
- btinfo->ftrace = NULL;
+ xfree (trash);
+ }
+
+ btinfo->begin = NULL;
+ btinfo->end = NULL;
+
+ xfree (btinfo->insn_history);
+ xfree (btinfo->call_history);
+
+ btinfo->insn_history = NULL;
+ btinfo->call_history = NULL;
}

/* See btrace.h. */
@@ -541,3 +874,451 @@ parse_xml_btrace (const char *buffer)

return btrace;
}
+
+/* See btrace.h. */
+
+const struct btrace_insn *
+btrace_insn_get (const struct btrace_insn_iterator *it)
+{
+ const struct btrace_function *bfun;
+ unsigned int index, end;
+
+ index = it->index;
+ bfun = it->function;
+
+ /* The index is within the bounds of this function's instruction vector. */
+ end = VEC_length (btrace_insn_s, bfun->insn);
+ gdb_assert (0 < end);
+ gdb_assert (index < end);
+
+ return VEC_index (btrace_insn_s, bfun->insn, index);
+}
+
+/* See btrace.h. */
+
+unsigned int
+btrace_insn_number (const struct btrace_insn_iterator *it)
+{
+ const struct btrace_function *bfun;
+
+ bfun = it->function;
+ return bfun->insn_offset + it->index;
+}
+
+/* See btrace.h. */
+
+void
+btrace_insn_begin (struct btrace_insn_iterator *it,
+ const struct btrace_thread_info *btinfo)
+{
+ const struct btrace_function *bfun;
+
+ bfun = btinfo->begin;
+ if (bfun == NULL)
+ error (_("No trace."));
+
+ it->function = bfun;
+ it->index = 0;
+}
+
+/* See btrace.h. */
+
+void
+btrace_insn_end (struct btrace_insn_iterator *it,
+ const struct btrace_thread_info *btinfo)
+{
+ const struct btrace_function *bfun;
+ unsigned int length;
+
+ bfun = btinfo->end;
+ if (bfun == NULL)
+ error (_("No trace."));
+
+ /* The last instruction in the last function is the current instruction.
+ We point to it - it is one past the end of the execution trace. */
+ length = VEC_length (btrace_insn_s, bfun->insn);
+
+ it->function = bfun;
+ it->index = length - 1;
+}
+
+/* See btrace.h. */
+
+unsigned int
+btrace_insn_next (struct btrace_insn_iterator *it, unsigned int stride)
+{
+ const struct btrace_function *bfun;
+ unsigned int index, steps;
+
+ bfun = it->function;
+ steps = 0;
+ index = it->index;
+
+ while (stride != 0)
+ {
+ unsigned int end, space, adv;
+
+ end = VEC_length (btrace_insn_s, bfun->insn);
+
+ gdb_assert (0 < end);
+ gdb_assert (index < end);
+
+ /* Compute the number of instructions remaining in this segment. */
+ space = end - index;
+
+ /* Advance the iterator as far as possible within this segment. */
+ adv = min (space, stride);
+ stride -= adv;
+ index += adv;
+ steps += adv;
+
+ /* Move to the next function if we're at the end of this one. */
+ if (index == end)
+ {
+ const struct btrace_function *next;
+
+ next = bfun->flow.next;
+ if (next == NULL)
+ {
+ /* We stepped past the last function.
+
+ Let's adjust the index to point to the last instruction in
+ the previous function. */
+ index -= 1;
+ steps -= 1;
+ break;
+ }
+
+ /* We now point to the first instruction in the new function. */
+ bfun = next;
+ index = 0;
+ }
+
+ /* We did make progress. */
+ gdb_assert (adv > 0);
+ }
+
+ /* Update the iterator. */
+ it->function = bfun;
+ it->index = index;
+
+ return steps;
+}
+
+/* See btrace.h. */
+
+unsigned int
+btrace_insn_prev (struct btrace_insn_iterator *it, unsigned int stride)
+{
+ const struct btrace_function *bfun;
+ unsigned int index, steps;
+
+ bfun = it->function;
+ steps = 0;
+ index = it->index;
+
+ while (stride != 0)
+ {
+ unsigned int adv;
+
+ /* Move to the previous function if we're at the start of this one. */
+ if (index == 0)
+ {
+ const struct btrace_function *prev;
+
+ prev = bfun->flow.prev;
+ if (prev == NULL)
+ break;
+
+ /* We point to one after the last instruction in the new function. */
+ bfun = prev;
+ index = VEC_length (btrace_insn_s, bfun->insn);
+
+ /* There is at least one instruction in this function segment. */
+ gdb_assert (index > 0);
+ }
+
+ /* Advance the iterator as far as possible within this segment. */
+ adv = min (index, stride);
+ stride -= adv;
+ index -= adv;
+ steps += adv;
+
+ /* We did make progress. */
+ gdb_assert (adv > 0);
+ }
+
+ /* Update the iterator. */
+ it->function = bfun;
+ it->index = index;
+
+ return steps;
+}
+
+/* See btrace.h. */
+
+int
+btrace_insn_cmp (const struct btrace_insn_iterator *lhs,
+ const struct btrace_insn_iterator *rhs)
+{
+ unsigned int lnum, rnum;
+
+ lnum = btrace_insn_number (lhs);
+ rnum = btrace_insn_number (rhs);
+
+ return (int) (lnum - rnum);
+}
+
+/* See btrace.h. */
+
+int
+btrace_find_insn_by_number (struct btrace_insn_iterator *it,
+ const struct btrace_thread_info *btinfo,
+ unsigned int number)
+{
+ const struct btrace_function *bfun;
+ unsigned int end;
+
+ for (bfun = btinfo->end; bfun != NULL; bfun = bfun->flow.prev)
+ if (bfun->insn_offset <= number)
+ break;
+
+ if (bfun == NULL)
+ return 0;
+
+ end = bfun->insn_offset + VEC_length (btrace_insn_s, bfun->insn);
+ if (end <= number)
+ return 0;
+
+ it->function = bfun;
+ it->index = number - bfun->insn_offset;
+
+ return 1;
+}
+
+/* See btrace.h. */
+
+const struct btrace_function *
+btrace_call_get (const struct btrace_call_iterator *it)
+{
+ return it->function;
+}
+
+/* See btrace.h. */
+
+unsigned int
+btrace_call_number (const struct btrace_call_iterator *it)
+{
+ const struct btrace_thread_info *btinfo;
+ const struct btrace_function *bfun;
+ unsigned int insns;
+
+ btinfo = it->btinfo;
+ bfun = it->function;
+ if (bfun != NULL)
+ return bfun->number;
+
+ /* For the end iterator, i.e. bfun == NULL, we return one more than the
+ number of the last function. */
+ bfun = btinfo->end;
+ insns = VEC_length (btrace_insn_s, bfun->insn);
+
+ /* If the function contains only a single instruction (i.e. the current
+ instruction), it will be skipped and its number is already the number
+ we seek. */
+ if (insns == 1)
+ return bfun->number;
+
+ /* Otherwise, return one more than the number of the last function. */
+ return bfun->number + 1;
+}
+
+/* See btrace.h. */
+
+void
+btrace_call_begin (struct btrace_call_iterator *it,
+ const struct btrace_thread_info *btinfo)
+{
+ const struct btrace_function *bfun;
+
+ bfun = btinfo->begin;
+ if (bfun == NULL)
+ error (_("No trace."));
+
+ it->btinfo = btinfo;
+ it->function = bfun;
+}
+
+/* See btrace.h. */
+
+void
+btrace_call_end (struct btrace_call_iterator *it,
+ const struct btrace_thread_info *btinfo)
+{
+ const struct btrace_function *bfun;
+
+ bfun = btinfo->end;
+ if (bfun == NULL)
+ error (_("No trace."));
+
+ it->btinfo = btinfo;
+ it->function = NULL;
+}
+
+/* See btrace.h. */
+
+unsigned int
+btrace_call_next (struct btrace_call_iterator *it, unsigned int stride)
+{
+ const struct btrace_function *bfun;
+ unsigned int steps;
+
+ bfun = it->function;
+ steps = 0;
+ while (bfun != NULL)
+ {
+ const struct btrace_function *next;
+ unsigned int insns;
+
+ next = bfun->flow.next;
+ if (next == NULL)
+ {
+ /* Ignore the last function if it only contains a single
+ (i.e. the current) instruction. */
+ insns = VEC_length (btrace_insn_s, bfun->insn);
+ if (insns == 1)
+ steps -= 1;
+ }
+
+ if (stride == steps)
+ break;
+
+ bfun = next;
+ steps += 1;
+ }
+
+ it->function = bfun;
+ return steps;
+}
+
+/* See btrace.h. */
+
+unsigned int
+btrace_call_prev (struct btrace_call_iterator *it, unsigned int stride)
+{
+ const struct btrace_thread_info *btinfo;
+ const struct btrace_function *bfun;
+ unsigned int steps;
+
+ bfun = it->function;
+ steps = 0;
+
+ if (bfun == NULL)
+ {
+ unsigned int insns;
+
+ btinfo = it->btinfo;
+ bfun = btinfo->end;
+ if (bfun == NULL)
+ return 0;
+
+ /* Ignore the last function if it only contains a single
+ (i.e. the current) instruction. */
+ insns = VEC_length (btrace_insn_s, bfun->insn);
+ if (insns == 1)
+ bfun = bfun->flow.prev;
+
+ if (bfun == NULL)
+ return 0;
+
+ steps += 1;
+ }
+
+ while (steps < stride)
+ {
+ const struct btrace_function *prev;
+
+ prev = bfun->flow.prev;
+ if (prev == NULL)
+ break;
+
+ bfun = prev;
+ steps += 1;
+ }
+
+ it->function = bfun;
+ return steps;
+}
+
+/* See btrace.h. */
+
+int
+btrace_call_cmp (const struct btrace_call_iterator *lhs,
+ const struct btrace_call_iterator *rhs)
+{
+ unsigned int lnum, rnum;
+
+ lnum = btrace_call_number (lhs);
+ rnum = btrace_call_number (rhs);
+
+ return (int) (lnum - rnum);
+}
+
+/* See btrace.h. */
+
+int
+btrace_find_call_by_number (struct btrace_call_iterator *it,
+ const struct btrace_thread_info *btinfo,
+ unsigned int number)
+{
+ const struct btrace_function *bfun;
+
+ for (bfun = btinfo->end; bfun != NULL; bfun = bfun->flow.prev)
+ {
+ unsigned int bnum;
+
+ bnum = bfun->number;
+ if (number == bnum)
+ {
+ it->btinfo = btinfo;
+ it->function = bfun;
+ return 1;
+ }
+
+ /* Functions are ordered and numbered consecutively. We could bail out
+ earlier. On the other hand, it is very unlikely that we search for
+ a nonexistent function. */
+ }
+
+ return 0;
+}
+
+/* See btrace.h. */
+
+void
+btrace_set_insn_history (struct btrace_thread_info *btinfo,
+ const struct btrace_insn_iterator *begin,
+ const struct btrace_insn_iterator *end)
+{
+ if (btinfo->insn_history == NULL)
+ btinfo->insn_history = xzalloc (sizeof (*btinfo->insn_history));
+
+ btinfo->insn_history->begin = *begin;
+ btinfo->insn_history->end = *end;
+}
+
+/* See btrace.h. */
+
+void
+btrace_set_call_history (struct btrace_thread_info *btinfo,
+ const struct btrace_call_iterator *begin,
+ const struct btrace_call_iterator *end)
+{
+ gdb_assert (begin->btinfo == end->btinfo);
+
+ if (btinfo->call_history == NULL)
+ btinfo->call_history = xzalloc (sizeof (*btinfo->call_history));
+
+ btinfo->call_history->begin = *begin;
+ btinfo->call_history->end = *end;
+}
diff --git a/gdb/btrace.h b/gdb/btrace.h
index bd8425d..f4b2cc1 100644
--- a/gdb/btrace.h
+++ b/gdb/btrace.h
@@ -29,63 +29,128 @@
#include "btrace-common.h"

struct thread_info;
+struct btrace_function;

/* A branch trace instruction.

This represents a single instruction in a branch trace. */
-struct btrace_inst
+struct btrace_insn
{
/* The address of this instruction. */
CORE_ADDR pc;
};

-/* A branch trace function.
+/* A vector of branch trace instructions. */
+typedef struct btrace_insn btrace_insn_s;
+DEF_VEC_O (btrace_insn_s);
+
+/* A doubly-linked list of branch trace function segments. */
+struct btrace_func_link
+{
+ struct btrace_function *prev;
+ struct btrace_function *next;
+};
+
+/* Flags for btrace function segments. */
+enum btrace_function_flag
+{
+ /* The 'up' link interpretation.
+ If set, it points to the function segment we returned to.
+ If clear, it points to the function segment we called from. */
+ BFUN_UP_LINKS_TO_RET = (1 << 0),
+
+ /* The 'up' link points to a tail call. This obviously only makes sense
+ if bfun_up_links_to_ret is clear. */
+ BFUN_UP_LINKS_TO_TAILCALL = (1 << 1)
+};
+
+/* A branch trace function segment.

This represents a function segment in a branch trace, i.e. a consecutive
- number of instructions belonging to the same function. */
-struct btrace_func
+ number of instructions belonging to the same function.
+
+ We do not allow function segments without any instructions. */
+struct btrace_function
{
- /* The full and minimal symbol for the function. One of them may be NULL. */
+ /* The full and minimal symbol for the function. Both may be NULL. */
struct minimal_symbol *msym;
struct symbol *sym;

+ /* The previous and next segment belonging to the same function.
+ If a function calls another function, the former will have at least
+ two segments: one before the call and another after the return. */
+ struct btrace_func_link segment;
+
+ /* The previous and next function in control flow order. */
+ struct btrace_func_link flow;
+
+ /* The directly preceding function segment in a (fake) call stack. */
+ struct btrace_function *up;
+
+ /* The instructions in this function segment.
+ The instruction vector will never be empty. */
+ VEC (btrace_insn_s) *insn;
+
+ /* The instruction number offset for the first instruction in this
+ function segment. */
+ unsigned int insn_offset;
+
+ /* The function number in control-flow order. */
+ unsigned int number;
+
+ /* The function level in a back trace across the entire branch trace.
+ A caller's level is one lower than the level of its callee.
+
+ Levels can be negative if we see returns for which we have not seen
+ the corresponding calls. The branch trace thread information provides
+ a fixup to normalize function levels so the smallest level is zero. */
+ int level;
+
/* The source line range of this function segment (both inclusive). */
int lbegin, lend;

- /* The instruction number range in the instruction trace corresponding
- to this function segment (both inclusive). */
- unsigned int ibegin, iend;
+ /* A bit-vector of btrace_function_flag. */
+ enum btrace_function_flag flags;
};

-/* Branch trace may also be represented as a vector of:
+/* A branch trace instruction iterator. */
+struct btrace_insn_iterator
+{
+ /* The branch trace function segment containing the instruction.
+ Will never be NULL. */
+ const struct btrace_function *function;

- - branch trace instructions starting with the oldest instruction.
- - branch trace functions starting with the oldest function. */
-typedef struct btrace_inst btrace_inst_s;
-typedef struct btrace_func btrace_func_s;
+ /* The index into the function segment's instruction vector. */
+ unsigned int index;
+};

-/* Define functions operating on branch trace vectors. */
-DEF_VEC_O (btrace_inst_s);
-DEF_VEC_O (btrace_func_s);
+/* A branch trace function call iterator. */
+struct btrace_call_iterator
+{
+ /* The branch trace information for this thread. Will never be NULL. */
+ const struct btrace_thread_info *btinfo;
+
+ /* The branch trace function segment.
+ This will be NULL for the iterator pointing to the end of the trace. */
+ const struct btrace_function *function;
+};

/* Branch trace iteration state for "record instruction-history". */
-struct btrace_insn_iterator
+struct btrace_insn_history
{
- /* The instruction index range from begin (inclusive) to end (exclusive)
- that has been covered last time.
- If end < begin, the branch trace has just been updated. */
- unsigned int begin;
- unsigned int end;
+ /* The branch trace instruction range from BEGIN (inclusive) to
+ END (exclusive) that has been covered last time. */
+ struct btrace_insn_iterator begin;
+ struct btrace_insn_iterator end;
};

/* Branch trace iteration state for "record function-call-history". */
-struct btrace_func_iterator
+struct btrace_call_history
{
- /* The function index range from begin (inclusive) to end (exclusive)
- that has been covered last time.
- If end < begin, the branch trace has just been updated. */
- unsigned int begin;
- unsigned int end;
+ /* The branch trace function range from BEGIN (inclusive) to END (exclusive)
+ that has been covered last time. */
+ struct btrace_call_iterator begin;
+ struct btrace_call_iterator end;
};

/* Branch trace information per thread.
@@ -103,16 +168,25 @@ struct btrace_thread_info
the underlying architecture. */
struct btrace_target_info *target;

- /* The current branch trace for this thread. */
- VEC (btrace_block_s) *btrace;
- VEC (btrace_inst_s) *itrace;
- VEC (btrace_func_s) *ftrace;
+ /* The current branch trace for this thread (both inclusive).
+
+ The last instruction of END is the current instruction, which is not
+ part of the execution history.
+ Both will be NULL if there is no branch trace available. If there is
+ branch trace available, both will be non-NULL. */
+ struct btrace_function *begin;
+ struct btrace_function *end;
+
+ /* The function level offset. When added to each function's LEVEL,
+ this normalizes the function levels such that the smallest level
+ becomes zero. */
+ int level;

/* The instruction history iterator. */
- struct btrace_insn_iterator insn_iterator;
+ struct btrace_insn_history *insn_history;

/* The function call history iterator. */
- struct btrace_func_iterator func_iterator;
+ struct btrace_call_history *call_history;
};

/* Enable branch tracing for a thread. */
@@ -139,4 +213,99 @@ extern void btrace_free_objfile (struct objfile *);
/* Parse a branch trace xml document into a block vector. */
extern VEC (btrace_block_s) *parse_xml_btrace (const char*);

+/* Dereference a branch trace instruction iterator. Return a pointer to the
+ instruction the iterator points to. */
+extern const struct btrace_insn *
+ btrace_insn_get (const struct btrace_insn_iterator *);
+
+/* Return the instruction number for a branch trace iterator.
+ Returns one past the maximum instruction number for the end iterator.
+ Returns zero if the iterator does not point to a valid instruction. */
+extern unsigned int btrace_insn_number (const struct btrace_insn_iterator *);
+
+/* Initialize a branch trace instruction iterator to point to the begin/end of
+ the branch trace. Throws an error if there is no branch trace. */
+extern void btrace_insn_begin (struct btrace_insn_iterator *,
+ const struct btrace_thread_info *);
+extern void btrace_insn_end (struct btrace_insn_iterator *,
+ const struct btrace_thread_info *);
+
+/* Increment/decrement a branch trace instruction iterator by at most STRIDE
+ instructions. Return the number of instructions by which the instruction
+ iterator has been advanced.
+ Returns zero, if the operation failed or STRIDE had been zero. */
+extern unsigned int btrace_insn_next (struct btrace_insn_iterator *,
+ unsigned int stride);
+extern unsigned int btrace_insn_prev (struct btrace_insn_iterator *,
+ unsigned int stride);
+
+/* Compare two branch trace instruction iterators.
+ Return a negative number if LHS < RHS.
+ Return zero if LHS == RHS.
+ Return a positive number if LHS > RHS. */
+extern int btrace_insn_cmp (const struct btrace_insn_iterator *lhs,
+ const struct btrace_insn_iterator *rhs);
+
+/* Find an instruction in the function branch trace by its number.
+ If the instruction is found, initialize the branch trace instruction
+ iterator to point to this instruction and return non-zero.
+ Return zero otherwise. */
+extern int btrace_find_insn_by_number (struct btrace_insn_iterator *,
+ const struct btrace_thread_info *,
+ unsigned int number);
+
+/* Dereference a branch trace call iterator. Return a pointer to the
+ function the iterator points to or NULL if the interator points past
+ the end of the branch trace. */
+extern const struct btrace_function *
+ btrace_call_get (const struct btrace_call_iterator *);
+
+/* Return the function number for a branch trace call iterator.
+ Returns one past the maximum function number for the end iterator.
+ Returns zero if the iterator does not point to a valid function. */
+extern unsigned int btrace_call_number (const struct btrace_call_iterator *);
+
+/* Initialize a branch trace call iterator to point to the begin/end of
+ the branch trace. Throws an error if there is no branch trace. */
+extern void btrace_call_begin (struct btrace_call_iterator *,
+ const struct btrace_thread_info *);
+extern void btrace_call_end (struct btrace_call_iterator *,
+ const struct btrace_thread_info *);
+
+/* Increment/decrement a branch trace call iterator by at most STRIDE function
+ segments. Return the number of function segments by which the call
+ iterator has been advanced.
+ Returns zero, if the operation failed or STRIDE had been zero. */
+extern unsigned int btrace_call_next (struct btrace_call_iterator *,
+ unsigned int stride);
+extern unsigned int btrace_call_prev (struct btrace_call_iterator *,
+ unsigned int stride);
+
+/* Compare two branch trace call iterators.
+ Return a negative number if LHS < RHS.
+ Return zero if LHS == RHS.
+ Return a positive number if LHS > RHS. */
+extern int btrace_call_cmp (const struct btrace_call_iterator *lhs,
+ const struct btrace_call_iterator *rhs);
+
+/* Find a function in the function branch trace by its NUMBER.
+ If the function is found, initialize the branch trace call
+ iterator to point to this function and return non-zero.
+ Return zero otherwise. */
+extern int btrace_find_call_by_number (struct btrace_call_iterator *,
+ const struct btrace_thread_info *,
+ unsigned int number);
+
+/* Set the branch trace instruction history from BEGIN (inclusive) to
+ END (exclusive). */
+extern void btrace_set_insn_history (struct btrace_thread_info *,
+ const struct btrace_insn_iterator *begin,
+ const struct btrace_insn_iterator *end);
+
+/* Set the branch trace function call history from BEGIN (inclusive) to
+ END (exclusive). */
+extern void btrace_set_call_history (struct btrace_thread_info *,
+ const struct btrace_call_iterator *begin,
+ const struct btrace_call_iterator *end);
+
#endif /* BTRACE_H */
diff --git a/gdb/record-btrace.c b/gdb/record-btrace.c
index 68f40c8..248dc2e 100644
--- a/gdb/record-btrace.c
+++ b/gdb/record-btrace.c
@@ -74,7 +74,7 @@ require_btrace (void)

btinfo = &tp->btrace;

- if (VEC_empty (btrace_inst_s, btinfo->itrace))
+ if (btinfo->begin == NULL)
error (_("No trace."));

return btinfo;
@@ -206,7 +206,7 @@ record_btrace_info (void)
{
struct btrace_thread_info *btinfo;
struct thread_info *tp;
- unsigned int insts, funcs;
+ unsigned int insns, calls;

DEBUG ("info");

@@ -216,12 +216,26 @@ record_btrace_info (void)

btrace_fetch (tp);

+ insns = 0;
+ calls = 0;
+
btinfo = &tp->btrace;
- insts = VEC_length (btrace_inst_s, btinfo->itrace);
- funcs = VEC_length (btrace_func_s, btinfo->ftrace);
+ if (btinfo->begin != NULL)
+ {
+ struct btrace_call_iterator call;
+ struct btrace_insn_iterator insn;
+
+ btrace_call_end (&call, btinfo);
+ btrace_call_prev (&call, 1);
+ calls = btrace_call_number (&call) + 1;
+
+ btrace_insn_end (&insn, btinfo);
+ btrace_insn_prev (&insn, 1);
+ insns = btrace_insn_number (&insn) + 1;
+ }

printf_unfiltered (_("Recorded %u instructions in %u functions for thread "
- "%d (%s).\n"), insts, funcs, tp->num,
+ "%d (%s).\n"), insns, calls, tp->num,
target_pid_to_str (tp->ptid));
}

@@ -236,27 +250,31 @@ ui_out_field_uint (struct ui_out *uiout, const char *fld, unsigned int val)
/* Disassemble a section of the recorded instruction trace. */

static void
-btrace_insn_history (struct btrace_thread_info *btinfo, struct ui_out *uiout,
- unsigned int begin, unsigned int end, int flags)
+btrace_insn_history (struct ui_out *uiout,
+ const struct btrace_insn_iterator *begin,
+ const struct btrace_insn_iterator *end, int flags)
{
struct gdbarch *gdbarch;
- struct btrace_inst *inst;
- unsigned int idx;
+ struct btrace_insn_iterator it;

- DEBUG ("itrace (0x%x): [%u; %u[", flags, begin, end);
+ DEBUG ("itrace (0x%x): [%u; %u)", flags, btrace_insn_number (begin),
+ btrace_insn_number (end));

gdbarch = target_gdbarch ();

- for (idx = begin; VEC_iterate (btrace_inst_s, btinfo->itrace, idx, inst)
- && idx < end; ++idx)
+ for (it = *begin; btrace_insn_cmp (&it, end) != 0; btrace_insn_next (&it, 1))
{
+ const struct btrace_insn *insn;
+
+ insn = btrace_insn_get (&it);
+
/* Print the instruction index. */
- ui_out_field_uint (uiout, "index", idx);
+ ui_out_field_uint (uiout, "index", btrace_insn_number (&it));
ui_out_text (uiout, "\t");

/* Disassembly with '/m' flag may not produce the expected result.
See PR gdb/11833. */
- gdb_disassembly (gdbarch, uiout, NULL, flags, 1, inst->pc, inst->pc + 1);
+ gdb_disassembly (gdbarch, uiout, NULL, flags, 1, insn->pc, insn->pc + 1);
}
}

@@ -266,72 +284,62 @@ static void
record_btrace_insn_history (int size, int flags)
{
struct btrace_thread_info *btinfo;
+ struct btrace_insn_history *history;
+ struct btrace_insn_iterator begin, end;
struct cleanup *uiout_cleanup;
struct ui_out *uiout;
- unsigned int context, last, begin, end;
+ unsigned int context, covered;

uiout = current_uiout;
uiout_cleanup = make_cleanup_ui_out_tuple_begin_end (uiout,
"insn history");
- btinfo = require_btrace ();
- last = VEC_length (btrace_inst_s, btinfo->itrace);
-
context = abs (size);
- begin = btinfo->insn_iterator.begin;
- end = btinfo->insn_iterator.end;
-
- DEBUG ("insn-history (0x%x): %d, prev: [%u; %u[", flags, size, begin, end);
-
if (context == 0)
error (_("Bad record instruction-history-size."));

- /* We start at the end. */
- if (end < begin)
- {
- /* Truncate the context, if necessary. */
- context = min (context, last);
-
- end = last;
- begin = end - context;
- }
- else if (size < 0)
+ btinfo = require_btrace ();
+ history = btinfo->insn_history;
+ if (history == NULL)
{
- if (begin == 0)
- {
- printf_unfiltered (_("At the start of the branch trace record.\n"));
-
- btinfo->insn_iterator.end = 0;
- return;
- }
+ /* No matter the direction, we start with the tail of the trace. */
+ btrace_insn_end (&begin, btinfo);
+ end = begin;

- /* Truncate the context, if necessary. */
- context = min (context, begin);
+ DEBUG ("insn-history (0x%x): %d", flags, size);

- end = begin;
- begin -= context;
+ covered = btrace_insn_prev (&begin, context);
}
else
{
- if (end == last)
- {
- printf_unfiltered (_("At the end of the branch trace record.\n"));
+ begin = history->begin;
+ end = history->end;

- btinfo->insn_iterator.begin = last;
- return;
- }
+ DEBUG ("insn-history (0x%x): %d, prev: [%u; %u)", flags, size,
+ btrace_insn_number (&begin), btrace_insn_number (&end));

- /* Truncate the context, if necessary. */
- context = min (context, last - end);
-
- begin = end;
- end += context;
+ if (size < 0)
+ {
+ end = begin;
+ covered = btrace_insn_prev (&begin, context);
+ }
+ else
+ {
+ begin = end;
+ covered = btrace_insn_next (&end, context);
+ }
}

- btrace_insn_history (btinfo, uiout, begin, end, flags);
-
- btinfo->insn_iterator.begin = begin;
- btinfo->insn_iterator.end = end;
+ if (covered > 0)
+ btrace_insn_history (uiout, &begin, &end, flags);
+ else
+ {
+ if (size < 0)
+ printf_unfiltered (_("At the start of the branch trace record.\n"));
+ else
+ printf_unfiltered (_("At the end of the branch trace record.\n"));
+ }

+ btrace_set_insn_history (btinfo, &begin, &end);
do_cleanups (uiout_cleanup);
}

@@ -341,39 +349,41 @@ static void
record_btrace_insn_history_range (ULONGEST from, ULONGEST to, int flags)
{
struct btrace_thread_info *btinfo;
+ struct btrace_insn_history *history;
+ struct btrace_insn_iterator begin, end;
struct cleanup *uiout_cleanup;
struct ui_out *uiout;
- unsigned int last, begin, end;
+ unsigned int low, high;
+ int found;

uiout = current_uiout;
uiout_cleanup = make_cleanup_ui_out_tuple_begin_end (uiout,
"insn history");
- btinfo = require_btrace ();
- last = VEC_length (btrace_inst_s, btinfo->itrace);
+ low = from;
+ high = to;

- begin = (unsigned int) from;
- end = (unsigned int) to;
-
- DEBUG ("insn-history (0x%x): [%u; %u[", flags, begin, end);
+ DEBUG ("insn-history (0x%x): [%u; %u)", flags, low, high);

/* Check for wrap-arounds. */
- if (begin != from || end != to)
+ if (low != from || high != to)
error (_("Bad range."));

- if (end <= begin)
+ if (high <= low)
error (_("Bad range."));

- if (last <= begin)
- error (_("Range out of bounds."));
+ btinfo = require_btrace ();

- /* Truncate the range, if necessary. */
- if (last < end)
- end = last;
+ found = btrace_find_insn_by_number (&begin, btinfo, low);
+ if (found == 0)
+ error (_("Range out of bounds."));

- btrace_insn_history (btinfo, uiout, begin, end, flags);
+ /* Silently truncate the range, if necessary. */
+ found = btrace_find_insn_by_number (&end, btinfo, high);
+ if (found == 0)
+ btrace_insn_end (&end, btinfo);

- btinfo->insn_iterator.begin = begin;
- btinfo->insn_iterator.end = end;
+ btrace_insn_history (uiout, &begin, &end, flags);
+ btrace_set_insn_history (btinfo, &begin, &end);

do_cleanups (uiout_cleanup);
}
@@ -412,23 +422,27 @@ record_btrace_insn_history_from (ULONGEST from, int size, int flags)
/* Print the instruction number range for a function call history line. */

static void
-btrace_func_history_insn_range (struct ui_out *uiout, struct btrace_func *bfun)
+btrace_call_history_insn_range (struct ui_out *uiout,
+ const struct btrace_function *bfun)
{
- ui_out_field_uint (uiout, "insn begin", bfun->ibegin);
+ unsigned int begin, end;

- if (bfun->ibegin == bfun->iend)
- return;
+ begin = bfun->insn_offset;
+ end = begin + VEC_length (btrace_insn_s, bfun->insn);

+ ui_out_field_uint (uiout, "insn begin", begin);
ui_out_text (uiout, "-");
- ui_out_field_uint (uiout, "insn end", bfun->iend);
+ ui_out_field_uint (uiout, "insn end", end);
}

/* Print the source line information for a function call history line. */

static void
-btrace_func_history_src_line (struct ui_out *uiout, struct btrace_func *bfun)
+btrace_call_history_src_line (struct ui_out *uiout,
+ const struct btrace_function *bfun)
{
struct symbol *sym;
+ int begin, end;

sym = bfun->sym;
if (sym == NULL)
@@ -437,54 +451,66 @@ btrace_func_history_src_line (struct ui_out *uiout, struct btrace_func *bfun)
ui_out_field_string (uiout, "file",
symtab_to_filename_for_display (sym->symtab));

- if (bfun->lend == 0)
+ begin = bfun->lbegin;
+ end = bfun->lend;
+
+ if (end < begin)
return;

ui_out_text (uiout, ":");
- ui_out_field_int (uiout, "min line", bfun->lbegin);
+ ui_out_field_int (uiout, "min line", begin);

- if (bfun->lend == bfun->lbegin)
+ if (end == begin)
return;

ui_out_text (uiout, "-");
- ui_out_field_int (uiout, "max line", bfun->lend);
+ ui_out_field_int (uiout, "max line", end);
}

/* Disassemble a section of the recorded function trace. */

static void
-btrace_func_history (struct btrace_thread_info *btinfo, struct ui_out *uiout,
- unsigned int begin, unsigned int end,
+btrace_call_history (struct ui_out *uiout,
+ const struct btrace_call_iterator *begin,
+ const struct btrace_call_iterator *end,
enum record_print_flag flags)
{
- struct btrace_func *bfun;
- unsigned int idx;
+ struct btrace_call_iterator it;

- DEBUG ("ftrace (0x%x): [%u; %u[", flags, begin, end);
+ DEBUG ("ftrace (0x%x): [%u; %u)", flags, btrace_call_number (begin),
+ btrace_call_number (end));

- for (idx = begin; VEC_iterate (btrace_func_s, btinfo->ftrace, idx, bfun)
- && idx < end; ++idx)
+ for (it = *begin; btrace_call_cmp (&it, end) < 0; btrace_call_next (&it, 1))
{
+ const struct btrace_function *bfun;
+ struct minimal_symbol *msym;
+ struct symbol *sym;
+
+ bfun = btrace_call_get (&it);
+ msym = bfun->msym;
+ sym = bfun->sym;
+
/* Print the function index. */
- ui_out_field_uint (uiout, "index", idx);
+ ui_out_field_uint (uiout, "index", bfun->number);
ui_out_text (uiout, "\t");

if ((flags & RECORD_PRINT_INSN_RANGE) != 0)
{
- btrace_func_history_insn_range (uiout, bfun);
+ btrace_call_history_insn_range (uiout, bfun);
ui_out_text (uiout, "\t");
}

if ((flags & RECORD_PRINT_SRC_LINE) != 0)
{
- btrace_func_history_src_line (uiout, bfun);
+ btrace_call_history_src_line (uiout, bfun);
ui_out_text (uiout, "\t");
}

- if (bfun->sym != NULL)
- ui_out_field_string (uiout, "function", SYMBOL_PRINT_NAME (bfun->sym));
- else if (bfun->msym != NULL)
- ui_out_field_string (uiout, "function", SYMBOL_PRINT_NAME (bfun->msym));
+ if (sym != NULL)
+ ui_out_field_string (uiout, "function", SYMBOL_PRINT_NAME (sym));
+ else if (msym != NULL)
+ ui_out_field_string (uiout, "function", SYMBOL_PRINT_NAME (msym));
+
ui_out_text (uiout, "\n");
}
}
@@ -495,72 +521,62 @@ static void
record_btrace_call_history (int size, int flags)
{
struct btrace_thread_info *btinfo;
+ struct btrace_call_history *history;
+ struct btrace_call_iterator begin, end;
struct cleanup *uiout_cleanup;
struct ui_out *uiout;
- unsigned int context, last, begin, end;
+ unsigned int context, covered;

uiout = current_uiout;
uiout_cleanup = make_cleanup_ui_out_tuple_begin_end (uiout,
"insn history");
- btinfo = require_btrace ();
- last = VEC_length (btrace_func_s, btinfo->ftrace);
-
context = abs (size);
- begin = btinfo->func_iterator.begin;
- end = btinfo->func_iterator.end;
-
- DEBUG ("func-history (0x%x): %d, prev: [%u; %u[", flags, size, begin, end);
-
if (context == 0)
error (_("Bad record function-call-history-size."));

- /* We start at the end. */
- if (end < begin)
- {
- /* Truncate the context, if necessary. */
- context = min (context, last);
-
- end = last;
- begin = end - context;
- }
- else if (size < 0)
+ btinfo = require_btrace ();
+ history = btinfo->call_history;
+ if (history == NULL)
{
- if (begin == 0)
- {
- printf_unfiltered (_("At the start of the branch trace record.\n"));
-
- btinfo->func_iterator.end = 0;
- return;
- }
+ /* No matter the direction, we start with the tail of the trace. */
+ btrace_call_end (&begin, btinfo);
+ end = begin;

- /* Truncate the context, if necessary. */
- context = min (context, begin);
+ DEBUG ("call-history (0x%x): %d", flags, size);

- end = begin;
- begin -= context;
+ covered = btrace_call_prev (&begin, context);
}
else
{
- if (end == last)
- {
- printf_unfiltered (_("At the end of the branch trace record.\n"));
+ begin = history->begin;
+ end = history->end;

- btinfo->func_iterator.begin = last;
- return;
- }
+ DEBUG ("call-history (0x%x): %d, prev: [%u; %u)", flags, size,
+ btrace_call_number (&begin), btrace_call_number (&end));

- /* Truncate the context, if necessary. */
- context = min (context, last - end);
-
- begin = end;
- end += context;
+ if (size < 0)
+ {
+ end = begin;
+ covered = btrace_call_prev (&begin, context);
+ }
+ else
+ {
+ begin = end;
+ covered = btrace_call_next (&end, context);
+ }
}

- btrace_func_history (btinfo, uiout, begin, end, flags);
-
- btinfo->func_iterator.begin = begin;
- btinfo->func_iterator.end = end;
+ if (covered > 0)
+ btrace_call_history (uiout, &begin, &end, flags);
+ else
+ {
+ if (size < 0)
+ printf_unfiltered (_("At the start of the branch trace record.\n"));
+ else
+ printf_unfiltered (_("At the end of the branch trace record.\n"));
+ }

+ btrace_set_call_history (btinfo, &begin, &end);
do_cleanups (uiout_cleanup);
}

@@ -570,39 +586,41 @@ static void
record_btrace_call_history_range (ULONGEST from, ULONGEST to, int flags)
{
struct btrace_thread_info *btinfo;
+ struct btrace_call_history *history;
+ struct btrace_call_iterator begin, end;
struct cleanup *uiout_cleanup;
struct ui_out *uiout;
- unsigned int last, begin, end;
+ unsigned int low, high;
+ int found;

uiout = current_uiout;
uiout_cleanup = make_cleanup_ui_out_tuple_begin_end (uiout,
"func history");
- btinfo = require_btrace ();
- last = VEC_length (btrace_func_s, btinfo->ftrace);
+ low = from;
+ high = to;

- begin = (unsigned int) from;
- end = (unsigned int) to;
-
- DEBUG ("func-history (0x%x): [%u; %u[", flags, begin, end);
+ DEBUG ("call-history (0x%x): [%u; %u)", flags, low, high);

/* Check for wrap-arounds. */
- if (begin != from || end != to)
+ if (low != from || high != to)
error (_("Bad range."));

- if (end <= begin)
+ if (high <= low)
error (_("Bad range."));

- if (last <= begin)
- error (_("Range out of bounds."));
+ btinfo = require_btrace ();

- /* Truncate the range, if necessary. */
- if (last < end)
- end = last;
+ found = btrace_find_call_by_number (&begin, btinfo, low);
+ if (found == 0)
+ error (_("Range out of bounds."));

- btrace_func_history (btinfo, uiout, begin, end, flags);
+ /* Silently truncate the range, if necessary. */
+ found = btrace_find_call_by_number (&end, btinfo, high);
+ if (found == 0)
+ btrace_call_end (&end, btinfo);

- btinfo->func_iterator.begin = begin;
- btinfo->func_iterator.end = end;
+ btrace_call_history (uiout, &begin, &end, flags);
+ btrace_set_call_history (btinfo, &begin, &end);

do_cleanups (uiout_cleanup);
}
diff --git a/gdb/testsuite/gdb.btrace/function_call_history.exp b/gdb/testsuite/gdb.btrace/function_call_history.exp
index 97447e1..7658637 100644
--- a/gdb/testsuite/gdb.btrace/function_call_history.exp
+++ b/gdb/testsuite/gdb.btrace/function_call_history.exp
@@ -204,16 +204,18 @@ set bp_location [gdb_get_line_number "bp.2" $testfile.c]
gdb_breakpoint $bp_location
gdb_continue_to_breakpoint "cont to $bp_location" ".*$testfile.c:$bp_location.*"

-# at this point we expect to have main, fib, ..., fib, main, where fib occurs 8 times,
-# so we limit the output to only show the latest 10 function calls
-gdb_test_no_output "set record function-call-history-size 10"
-set message "show recursive function call history"
-gdb_test_multiple "record function-call-history" $message {
- -re "13\tmain\r\n14\tfib\r\n15\tfib\r\n16\tfib\r\n17\tfib\r\n18\tfib\r\n19\tfib\r\n20\tfib\r\n21\tfib\r\n22 main\r\n$gdb_prompt $" {
- pass $message
- }
- -re "13\tinc\r\n14\tmain\r\n15\tinc\r\n16\tmain\r\n17\tinc\r\n18\tmain\r\n19\tinc\r\n20\tmain\r\n21\tfib\r\n22\tmain\r\n$gdb_prompt $" {
- # recursive function calls appear only as 1 call
- kfail "gdb/15240" $message
- }
-}
+# at this point we expect to have main, fib, ..., fib, main, where fib occurs 9 times,
+# so we limit the output to only show the latest 11 function calls
+gdb_test_no_output "set record function-call-history-size 11"
+gdb_test "record function-call-history" "
+20\tmain\r
+21\tfib\r
+22\tfib\r
+23\tfib\r
+24\tfib\r
+25\tfib\r
+26\tfib\r
+27\tfib\r
+28\tfib\r
+29\tfib\r
+30\tmain" "show recursive function call history"
diff --git a/gdb/testsuite/gdb.btrace/instruction_history.exp b/gdb/testsuite/gdb.btrace/instruction_history.exp
index c1a61b7..377dca1 100644
--- a/gdb/testsuite/gdb.btrace/instruction_history.exp
+++ b/gdb/testsuite/gdb.btrace/instruction_history.exp
@@ -47,18 +47,18 @@ gdb_continue_to_breakpoint "cont to $bp_location" ".*$srcfile2:$bp_location.*"
# it is necessary to count the number of lines that are
# shown by the "record instruction-history" command.

+set traced {}
set testname "determine number of recorded instructions"
gdb_test_multiple "info record" $testname {
-re "Active record target: record-btrace\r\nRecorded \(\[0-9\]*\) instructions in \(\[0-9\]*\) functions for thread 1 .*\\.\r\n$gdb_prompt $" {
set traced $expect_out(1,string)
- set traced_functions $expect_out(2,string)
pass $testname
}
}

-# we have exactly 7 instructions here
-set message "exactly 7 instructions"
-if { $traced != 7 } {
+# we have exactly 6 instructions here
+set message "exactly 6 instructions"
+if { $traced != 6 } {
fail $message
} else {
pass $message
@@ -144,6 +144,8 @@ if { $lines != $history_size } {
pass $message
}

+set history_size 2
+gdb_test_no_output "set record instruction-history-size $history_size"
set message "browse history forward middle"
set lines [test_lines_length "record instruction-history +" $message]
if { $lines != $history_size } {
@@ -165,6 +167,8 @@ gdb_test "record instruction-history" "At the end of the branch trace record\\."
# make sure we cannot move further
gdb_test "record instruction-history" "At the end of the branch trace record\\." "browse history forward beyond 2"

+set history_size 3
+gdb_test_no_output "set record instruction-history-size $history_size"
set message "browse history backward last"
set lines [test_lines_length "record instruction-history -" $message]
if { $lines != $history_size } {
@@ -173,6 +177,8 @@ if { $lines != $history_size } {
pass $message
}

+set history_size 2
+gdb_test_no_output "set record instruction-history-size $history_size"
set message "browse history backward middle"
set lines [test_lines_length "record instruction-history -" $message]
if { $lines != $history_size } {
--
1.8.3.1