/* Branch trace support for GDB, the GNU debugger.
- Copyright (C) 2013 Free Software Foundation, Inc.
+ Copyright (C) 2013-2014 Free Software Foundation, Inc.
Contributed by Intel Corp. <markus.t.metzger@intel.com>
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
+#include "defs.h"
#include "btrace.h"
#include "gdbthread.h"
-#include "exceptions.h"
#include "inferior.h"
#include "target.h"
#include "record.h"
#include "source.h"
#include "filenames.h"
#include "xml-support.h"
+#include "regcache.h"
/* Print a record debug message. Use do ... while (0) to avoid ambiguities
when used in if statements. */
#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;
return SYMBOL_PRINT_NAME (sym);
if (msym != NULL)
- return SYMBOL_PRINT_NAME (msym);
+ return MSYMBOL_PRINT_NAME (msym);
return "<unknown>";
}
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;
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;
/* If the minimal symbol changed, we certainly switched functions. */
if (mfun != NULL && msym != NULL
- && strcmp (SYMBOL_LINKAGE_NAME (mfun), SYMBOL_LINKAGE_NAME (msym)) != 0)
+ && strcmp (MSYMBOL_LINKAGE_NAME (mfun), MSYMBOL_LINKAGE_NAME (msym)) != 0)
return 1;
/* If the symbol changed, we certainly switched functions. */
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 = "";
-
- if (filename == NULL)
- filename = "";
+ bfile = symtab_to_fullname (sym->symtab);
- return (filename_cmp (bfile, filename) != 0);
+ return (filename_cmp (bfile, fullname) != 0);
}
-/* Compute the function trace from the instruction trace. */
+/* 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 VEC (btrace_func_s) *
-compute_ftrace (VEC (btrace_inst_s) *itrace)
+static struct btrace_function *
+ftrace_new_function (struct btrace_function *prev,
+ struct minimal_symbol *mfun,
+ struct symbol *fun)
{
- VEC (btrace_func_s) *ftrace;
- struct btrace_inst *binst;
- struct btrace_func *bfun;
- unsigned int idx;
+ struct btrace_function *bfun;
- DEBUG ("compute ftrace");
+ bfun = xzalloc (sizeof (*bfun));
+
+ bfun->msym = mfun;
+ bfun->sym = fun;
+ bfun->flow.prev = prev;
- ftrace = NULL;
- bfun = NULL;
+ /* We start with the identities of min and max, respectively. */
+ bfun->lbegin = INT_MAX;
+ bfun->lend = INT_MIN;
- for (idx = 0; VEC_iterate (btrace_inst_s, itrace, idx, binst); ++idx)
+ if (prev == NULL)
{
- struct symtab_and_line sal;
- struct minimal_symbol *mfun;
- struct symbol *fun;
- const char *filename;
- CORE_ADDR pc;
+ /* Start counting at one. */
+ bfun->number = 1;
+ bfun->insn_offset = 1;
+ }
+ else
+ {
+ gdb_assert (prev->flow.next == NULL);
+ prev->flow.next = bfun;
- pc = binst->pc;
+ bfun->number = prev->number + 1;
+ bfun->insn_offset = (prev->insn_offset
+ + VEC_length (btrace_insn_s, prev->insn));
+ }
- /* 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);
+ return bfun;
+}
- if (fun == NULL && mfun == NULL)
- {
- DEBUG_FTRACE ("no symbol at %u, pc=%s", idx,
- core_addr_to_string_nz (pc));
- continue;
- }
+/* Update the UP field of a function segment. */
- /* If we're switching functions, we start over. */
- if (ftrace_function_switched (bfun, mfun, fun))
- {
- bfun = VEC_safe_push (btrace_func_s, ftrace, NULL);
+static void
+ftrace_update_caller (struct btrace_function *bfun,
+ struct btrace_function *caller,
+ enum btrace_function_flag flags)
+{
+ if (bfun->up != NULL)
+ ftrace_debug (bfun, "updating caller");
- ftrace_init_func (bfun, mfun, fun, idx);
- ftrace_debug (bfun, "init");
- }
+ bfun->up = caller;
+ bfun->flags = flags;
- /* Update the instruction range. */
- bfun->iend = idx;
- ftrace_debug (bfun, "update insns");
+ ftrace_debug (bfun, "set caller");
+}
- /* Let's see if we have source correlation, as well. */
- sal = find_pc_line (pc, 0);
- if (sal.symtab == NULL || sal.line == 0)
- {
- DEBUG_FTRACE ("no lines at %u, pc=%s", idx,
- core_addr_to_string_nz (pc));
- continue;
- }
+/* Fix up the caller for all segments of a function. */
- /* 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))
- {
- DEBUG_FTRACE ("ignoring file at %u, pc=%s, file=%s", idx,
- core_addr_to_string_nz (pc), filename);
- continue;
- }
+static void
+ftrace_fixup_caller (struct btrace_function *bfun,
+ struct btrace_function *caller,
+ enum btrace_function_flag flags)
+{
+ struct btrace_function *prev, *next;
- /* Update the line range. */
- bfun->lbegin = min (bfun->lbegin, sal.line);
- bfun->lend = max (bfun->lend, sal.line);
- ftrace_debug (bfun, "update lines");
- }
+ ftrace_update_caller (bfun, caller, flags);
- return ftrace;
+ /* 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);
}
-/* See btrace.h. */
+/* 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. */
-void
-btrace_enable (struct thread_info *tp)
+static struct btrace_function *
+ftrace_new_call (struct btrace_function *caller,
+ struct minimal_symbol *mfun,
+ struct symbol *fun)
{
- if (tp->btrace.target != NULL)
- return;
+ struct btrace_function *bfun;
- if (!target_supports_btrace ())
- error (_("Target does not support branch tracing."));
+ bfun = ftrace_new_function (caller, mfun, fun);
+ bfun->up = caller;
+ bfun->level = caller->level + 1;
- DEBUG ("enable thread %d (%s)", tp->num, target_pid_to_str (tp->ptid));
+ ftrace_debug (bfun, "new call");
- tp->btrace.target = target_enable_btrace (tp->ptid);
+ return bfun;
}
-/* See btrace.h. */
+/* 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. */
-void
-btrace_disable (struct thread_info *tp)
+static struct btrace_function *
+ftrace_new_tailcall (struct btrace_function *caller,
+ struct minimal_symbol *mfun,
+ struct symbol *fun)
{
- struct btrace_thread_info *btp = &tp->btrace;
- int errcode = 0;
-
- if (btp->target == NULL)
- return;
+ struct btrace_function *bfun;
- DEBUG ("disable thread %d (%s)", tp->num, target_pid_to_str (tp->ptid));
+ bfun = ftrace_new_function (caller, mfun, fun);
+ bfun->up = caller;
+ bfun->level = caller->level + 1;
+ bfun->flags |= BFUN_UP_LINKS_TO_TAILCALL;
- target_disable_btrace (btp->target);
- btp->target = NULL;
+ ftrace_debug (bfun, "new tail call");
- btrace_clear (tp);
+ return bfun;
}
-/* See btrace.h. */
+/* Find the innermost caller in the back trace of BFUN with MFUN/FUN
+ symbol information. */
-void
-btrace_teardown (struct thread_info *tp)
+static struct btrace_function *
+ftrace_find_caller (struct btrace_function *bfun,
+ struct minimal_symbol *mfun,
+ struct symbol *fun)
{
- struct btrace_thread_info *btp = &tp->btrace;
- int errcode = 0;
-
- if (btp->target == NULL)
- return;
-
- DEBUG ("teardown thread %d (%s)", tp->num, target_pid_to_str (tp->ptid));
+ for (; bfun != NULL; bfun = bfun->up)
+ {
+ /* Skip functions with incompatible symbol information. */
+ if (ftrace_function_switched (bfun, mfun, fun))
+ continue;
- target_teardown_btrace (btp->target);
- btp->target = NULL;
+ /* This is the function segment we're looking for. */
+ break;
+ }
- btrace_clear (tp);
+ return bfun;
}
-/* See btrace.h. */
+/* 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). */
-void
-btrace_fetch (struct thread_info *tp)
+static struct btrace_function *
+ftrace_find_call (struct gdbarch *gdbarch, struct btrace_function *bfun)
{
- struct btrace_thread_info *btinfo;
- VEC (btrace_block_s) *btrace;
-
- DEBUG ("fetch thread %d (%s)", tp->num, target_pid_to_str (tp->ptid));
-
- btinfo = &tp->btrace;
- if (btinfo->target == NULL)
- return;
+ for (; bfun != NULL; bfun = bfun->up)
+ {
+ struct btrace_insn *last;
+ CORE_ADDR pc;
- btrace = target_read_btrace (btinfo->target, btrace_read_new);
- if (VEC_empty (btrace_block_s, btrace))
- return;
+ /* We do not allow empty function segments. */
+ gdb_assert (!VEC_empty (btrace_insn_s, bfun->insn));
- btrace_clear (tp);
+ last = VEC_last (btrace_insn_s, bfun->insn);
+ pc = last->pc;
- btinfo->btrace = btrace;
- btinfo->itrace = compute_itrace (btinfo->btrace);
- btinfo->ftrace = compute_ftrace (btinfo->itrace);
+ if (gdbarch_insn_is_call (gdbarch, pc))
+ break;
+ }
- /* Initialize branch trace iterators. */
- btrace_init_insn_iterator (btinfo);
- btrace_init_func_iterator (btinfo);
+ return bfun;
}
-/* See btrace.h. */
+/* 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. */
-void
-btrace_clear (struct thread_info *tp)
+static struct btrace_function *
+ftrace_new_return (struct gdbarch *gdbarch,
+ struct btrace_function *prev,
+ struct minimal_symbol *mfun,
+ struct symbol *fun)
{
- struct btrace_thread_info *btinfo;
+ struct btrace_function *bfun, *caller;
- DEBUG ("clear thread %d (%s)", tp->num, target_pid_to_str (tp->ptid));
+ bfun = ftrace_new_function (prev, mfun, fun);
- btinfo = &tp->btrace;
+ /* 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);
- VEC_free (btrace_block_s, btinfo->btrace);
- VEC_free (btrace_inst_s, btinfo->itrace);
- VEC_free (btrace_func_s, btinfo->ftrace);
+ caller->segment.next = bfun;
+ bfun->segment.prev = caller;
- btinfo->btrace = NULL;
- btinfo->itrace = NULL;
- btinfo->ftrace = NULL;
-}
+ /* Maintain the function level. */
+ bfun->level = caller->level;
-/* See btrace.h. */
+ /* Maintain the call stack. */
+ bfun->up = caller->up;
+ bfun->flags = caller->flags;
-void
-btrace_free_objfile (struct objfile *objfile)
-{
- struct thread_info *tp;
+ 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. */
- DEBUG ("free objfile");
+ /* Let's search for some actual call. */
+ caller = ftrace_find_call (gdbarch, prev->up);
+ if (caller == NULL)
+ {
+ /* There is no call in PREV's back trace. We assume that the
+ branch trace did not include it. */
- ALL_THREADS (tp)
- btrace_clear (tp);
-}
+ /* Let's find the topmost call function - this skips tail calls. */
+ while (prev->up != NULL)
+ prev = prev->up;
-#if defined (HAVE_LIBEXPAT)
+ /* 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;
-/* Check the btrace document version. */
+ /* Fix up the call stack for PREV. */
+ ftrace_fixup_caller (prev, bfun, BFUN_UP_LINKS_TO_RET);
-static void
-check_xml_btrace_version (struct gdb_xml_parser *parser,
- const struct gdb_xml_element *element,
- void *user_data, VEC (gdb_xml_value_s) *attributes)
-{
- const char *version = xml_find_attribute (attributes, "version")->value;
+ ftrace_debug (bfun, "new return - no caller");
+ }
+ else
+ {
+ /* 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;
- if (strcmp (version, "1.0") != 0)
- gdb_xml_error (parser, _("Unsupported btrace version: \"%s\""), version);
+ ftrace_debug (bfun, "new return - unknown caller");
+ }
+ }
+
+ return bfun;
}
-/* Parse a btrace "block" xml record. */
+/* 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 void
-parse_xml_btrace_block (struct gdb_xml_parser *parser,
- const struct gdb_xml_element *element,
- void *user_data, VEC (gdb_xml_value_s) *attributes)
+static struct btrace_function *
+ftrace_new_switch (struct btrace_function *prev,
+ struct minimal_symbol *mfun,
+ struct symbol *fun)
{
- VEC (btrace_block_s) **btrace;
- struct btrace_block *block;
- ULONGEST *begin, *end;
+ struct btrace_function *bfun;
- btrace = user_data;
- block = VEC_safe_push (btrace_block_s, *btrace, NULL);
+ /* This is an unexplained function switch. The call stack will likely
+ be wrong at this point. */
+ bfun = ftrace_new_function (prev, mfun, fun);
- begin = xml_find_attribute (attributes, "begin")->value;
- end = xml_find_attribute (attributes, "end")->value;
+ /* We keep the function level. */
+ bfun->level = prev->level;
- block->begin = *begin;
- block->end = *end;
+ ftrace_debug (bfun, "new switch");
+
+ return bfun;
}
-static const struct gdb_xml_attribute block_attributes[] = {
- { "begin", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
- { "end", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
- { NULL, GDB_XML_AF_NONE, NULL, NULL }
-};
+/* Update BFUN with respect to the instruction at PC. This may create new
+ function segments.
+ Return the chronologically latest function segment, never NULL. */
-static const struct gdb_xml_attribute btrace_attributes[] = {
- { "version", GDB_XML_AF_NONE, NULL, NULL },
- { NULL, GDB_XML_AF_NONE, NULL, 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);
-static const struct gdb_xml_element btrace_children[] = {
- { "block", block_attributes, NULL,
- GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL, parse_xml_btrace_block, NULL },
- { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
-};
+ /* 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);
-static const struct gdb_xml_element btrace_elements[] = {
- { "btrace", btrace_attributes, btrace_children, GDB_XML_EF_NONE,
- check_xml_btrace_version, NULL },
- { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
-};
+ if (last != NULL)
+ {
+ CORE_ADDR lpc;
-#endif /* defined (HAVE_LIBEXPAT) */
+ lpc = last->pc;
-/* See btrace.h. */
+ /* Check for returns. */
+ if (gdbarch_insn_is_ret (gdbarch, lpc))
+ return ftrace_new_return (gdbarch, bfun, mfun, fun);
-VEC (btrace_block_s) *
-parse_xml_btrace (const char *buffer)
-{
- VEC (btrace_block_s) *btrace = NULL;
- struct cleanup *cleanup;
- int errcode;
+ /* Check for calls. */
+ if (gdbarch_insn_is_call (gdbarch, lpc))
+ {
+ int size;
-#if defined (HAVE_LIBEXPAT)
+ size = gdb_insn_length (gdbarch, lpc);
- cleanup = make_cleanup (VEC_cleanup (btrace_block_s), &btrace);
- errcode = gdb_xml_parse_quick (_("btrace"), "btrace.dtd", btrace_elements,
- buffer, &btrace);
- if (errcode != 0)
- {
- do_cleanups (cleanup);
- return NULL;
+ /* Ignore calls to the next instruction. They are used for PIC. */
+ if (lpc + size != pc)
+ return ftrace_new_call (bfun, mfun, fun);
+ }
}
- /* Keep parse results. */
- discard_cleanups (cleanup);
+ /* 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));
-#else /* !defined (HAVE_LIBEXPAT) */
+ if (last != NULL)
+ {
+ CORE_ADDR start, lpc;
- error (_("Cannot process branch trace. XML parsing is not supported."));
+ start = get_pc_function_start (pc);
-#endif /* !defined (HAVE_LIBEXPAT) */
+ /* 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;
- return btrace;
+ lpc = last->pc;
+
+ /* Jumps indicate optimized tail calls. */
+ if (start == pc && gdbarch_insn_is_jump (gdbarch, lpc))
+ return ftrace_new_tailcall (bfun, mfun, fun);
+ }
+
+ 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 = btinfo->begin;
+ end = btinfo->end;
+ level = begin != NULL ? -btinfo->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.
+ For all but the last block, we do it here. */
+ if (blk != 0)
+ 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;
+
+ /* Maintain the function level offset.
+ For the last block, we do it here to not consider the last
+ instruction.
+ Since the last instruction corresponds to the current instruction
+ and is not really part of the execution history, it shouldn't
+ affect the level. */
+ if (blk == 0)
+ level = min (level, end->level);
+ }
+ }
+
+ 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;
+}
+
+/* Add an entry for the current PC. */
+
+static void
+btrace_add_pc (struct thread_info *tp)
+{
+ VEC (btrace_block_s) *btrace;
+ struct btrace_block *block;
+ struct regcache *regcache;
+ struct cleanup *cleanup;
+ CORE_ADDR pc;
+
+ regcache = get_thread_regcache (tp->ptid);
+ pc = regcache_read_pc (regcache);
+
+ btrace = NULL;
+ cleanup = make_cleanup (VEC_cleanup (btrace_block_s), &btrace);
+
+ block = VEC_safe_push (btrace_block_s, btrace, NULL);
+ block->begin = pc;
+ block->end = pc;
+
+ btrace_compute_ftrace (&tp->btrace, btrace);
+
+ do_cleanups (cleanup);
+}
+
+/* See btrace.h. */
+
+void
+btrace_enable (struct thread_info *tp)
+{
+ if (tp->btrace.target != NULL)
+ return;
+
+ if (!target_supports_btrace ())
+ error (_("Target does not support branch tracing."));
+
+ DEBUG ("enable thread %d (%s)", tp->num, target_pid_to_str (tp->ptid));
+
+ tp->btrace.target = target_enable_btrace (tp->ptid);
+
+ /* Add an entry for the current PC so we start tracing from where we
+ enabled it. */
+ if (tp->btrace.target != NULL)
+ btrace_add_pc (tp);
+}
+
+/* See btrace.h. */
+
+void
+btrace_disable (struct thread_info *tp)
+{
+ struct btrace_thread_info *btp = &tp->btrace;
+ int errcode = 0;
+
+ if (btp->target == NULL)
+ return;
+
+ DEBUG ("disable thread %d (%s)", tp->num, target_pid_to_str (tp->ptid));
+
+ target_disable_btrace (btp->target);
+ btp->target = NULL;
+
+ btrace_clear (tp);
+}
+
+/* See btrace.h. */
+
+void
+btrace_teardown (struct thread_info *tp)
+{
+ struct btrace_thread_info *btp = &tp->btrace;
+ int errcode = 0;
+
+ if (btp->target == NULL)
+ return;
+
+ DEBUG ("teardown thread %d (%s)", tp->num, target_pid_to_str (tp->ptid));
+
+ target_teardown_btrace (btp->target);
+ btp->target = NULL;
+
+ btrace_clear (tp);
+}
+
+/* Adjust the block trace in order to stitch old and new trace together.
+ BTRACE is the new delta trace between the last and the current stop.
+ BTINFO is the old branch trace until the last stop.
+ May modify BTRACE as well as the existing trace in BTINFO.
+ Return 0 on success, -1 otherwise. */
+
+static int
+btrace_stitch_trace (VEC (btrace_block_s) **btrace,
+ const struct btrace_thread_info *btinfo)
+{
+ struct btrace_function *last_bfun;
+ struct btrace_insn *last_insn;
+ btrace_block_s *first_new_block;
+
+ /* If we don't have trace, there's nothing to do. */
+ if (VEC_empty (btrace_block_s, *btrace))
+ return 0;
+
+ last_bfun = btinfo->end;
+ gdb_assert (last_bfun != NULL);
+
+ /* Beware that block trace starts with the most recent block, so the
+ chronologically first block in the new trace is the last block in
+ the new trace's block vector. */
+ first_new_block = VEC_last (btrace_block_s, *btrace);
+ last_insn = VEC_last (btrace_insn_s, last_bfun->insn);
+
+ /* If the current PC at the end of the block is the same as in our current
+ trace, there are two explanations:
+ 1. we executed the instruction and some branch brought us back.
+ 2. we have not made any progress.
+ In the first case, the delta trace vector should contain at least two
+ entries.
+ In the second case, the delta trace vector should contain exactly one
+ entry for the partial block containing the current PC. Remove it. */
+ if (first_new_block->end == last_insn->pc
+ && VEC_length (btrace_block_s, *btrace) == 1)
+ {
+ VEC_pop (btrace_block_s, *btrace);
+ return 0;
+ }
+
+ DEBUG ("stitching %s to %s", ftrace_print_insn_addr (last_insn),
+ core_addr_to_string_nz (first_new_block->end));
+
+ /* Do a simple sanity check to make sure we don't accidentally end up
+ with a bad block. This should not occur in practice. */
+ if (first_new_block->end < last_insn->pc)
+ {
+ warning (_("Error while trying to read delta trace. Falling back to "
+ "a full read."));
+ return -1;
+ }
+
+ /* We adjust the last block to start at the end of our current trace. */
+ gdb_assert (first_new_block->begin == 0);
+ first_new_block->begin = last_insn->pc;
+
+ /* We simply pop the last insn so we can insert it again as part of
+ the normal branch trace computation.
+ Since instruction iterators are based on indices in the instructions
+ vector, we don't leave any pointers dangling. */
+ DEBUG ("pruning insn at %s for stitching",
+ ftrace_print_insn_addr (last_insn));
+
+ VEC_pop (btrace_insn_s, last_bfun->insn);
+
+ /* The instructions vector may become empty temporarily if this has
+ been the only instruction in this function segment.
+ This violates the invariant but will be remedied shortly by
+ btrace_compute_ftrace when we add the new trace. */
+ return 0;
+}
+
+/* Clear the branch trace histories in BTINFO. */
+
+static void
+btrace_clear_history (struct btrace_thread_info *btinfo)
+{
+ xfree (btinfo->insn_history);
+ xfree (btinfo->call_history);
+ xfree (btinfo->replay);
+
+ btinfo->insn_history = NULL;
+ btinfo->call_history = NULL;
+ btinfo->replay = NULL;
+}
+
+/* See btrace.h. */
+
+void
+btrace_fetch (struct thread_info *tp)
+{
+ struct btrace_thread_info *btinfo;
+ struct btrace_target_info *tinfo;
+ VEC (btrace_block_s) *btrace;
+ struct cleanup *cleanup;
+ int errcode;
+
+ DEBUG ("fetch thread %d (%s)", tp->num, target_pid_to_str (tp->ptid));
+
+ btrace = NULL;
+ btinfo = &tp->btrace;
+ tinfo = btinfo->target;
+ if (tinfo == NULL)
+ return;
+
+ /* There's no way we could get new trace while replaying.
+ On the other hand, delta trace would return a partial record with the
+ current PC, which is the replay PC, not the last PC, as expected. */
+ if (btinfo->replay != NULL)
+ return;
+
+ cleanup = make_cleanup (VEC_cleanup (btrace_block_s), &btrace);
+
+ /* Let's first try to extend the trace we already have. */
+ if (btinfo->end != NULL)
+ {
+ errcode = target_read_btrace (&btrace, tinfo, BTRACE_READ_DELTA);
+ if (errcode == 0)
+ {
+ /* Success. Let's try to stitch the traces together. */
+ errcode = btrace_stitch_trace (&btrace, btinfo);
+ }
+ else
+ {
+ /* We failed to read delta trace. Let's try to read new trace. */
+ errcode = target_read_btrace (&btrace, tinfo, BTRACE_READ_NEW);
+
+ /* If we got any new trace, discard what we have. */
+ if (errcode == 0 && !VEC_empty (btrace_block_s, btrace))
+ btrace_clear (tp);
+ }
+
+ /* If we were not able to read the trace, we start over. */
+ if (errcode != 0)
+ {
+ btrace_clear (tp);
+ errcode = target_read_btrace (&btrace, tinfo, BTRACE_READ_ALL);
+ }
+ }
+ else
+ errcode = target_read_btrace (&btrace, tinfo, BTRACE_READ_ALL);
+
+ /* If we were not able to read the branch trace, signal an error. */
+ if (errcode != 0)
+ error (_("Failed to read branch trace."));
+
+ /* Compute the trace, provided we have any. */
+ if (!VEC_empty (btrace_block_s, btrace))
+ {
+ btrace_clear_history (btinfo);
+ btrace_compute_ftrace (btinfo, btrace);
+ }
+
+ do_cleanups (cleanup);
+}
+
+/* See btrace.h. */
+
+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));
+
+ /* Make sure btrace frames that may hold a pointer into the branch
+ trace data are destroyed. */
+ reinit_frame_cache ();
+
+ btinfo = &tp->btrace;
+
+ it = btinfo->begin;
+ while (it != NULL)
+ {
+ trash = it;
+ it = it->flow.next;
+
+ xfree (trash);
+ }
+
+ btinfo->begin = NULL;
+ btinfo->end = NULL;
+
+ btrace_clear_history (btinfo);
+}
+
+/* See btrace.h. */
+
+void
+btrace_free_objfile (struct objfile *objfile)
+{
+ struct thread_info *tp;
+
+ DEBUG ("free objfile");
+
+ ALL_NON_EXITED_THREADS (tp)
+ btrace_clear (tp);
+}
+
+#if defined (HAVE_LIBEXPAT)
+
+/* Check the btrace document version. */
+
+static void
+check_xml_btrace_version (struct gdb_xml_parser *parser,
+ const struct gdb_xml_element *element,
+ void *user_data, VEC (gdb_xml_value_s) *attributes)
+{
+ const char *version = xml_find_attribute (attributes, "version")->value;
+
+ if (strcmp (version, "1.0") != 0)
+ gdb_xml_error (parser, _("Unsupported btrace version: \"%s\""), version);
+}
+
+/* Parse a btrace "block" xml record. */
+
+static void
+parse_xml_btrace_block (struct gdb_xml_parser *parser,
+ const struct gdb_xml_element *element,
+ void *user_data, VEC (gdb_xml_value_s) *attributes)
+{
+ VEC (btrace_block_s) **btrace;
+ struct btrace_block *block;
+ ULONGEST *begin, *end;
+
+ btrace = user_data;
+ block = VEC_safe_push (btrace_block_s, *btrace, NULL);
+
+ begin = xml_find_attribute (attributes, "begin")->value;
+ end = xml_find_attribute (attributes, "end")->value;
+
+ block->begin = *begin;
+ block->end = *end;
+}
+
+static const struct gdb_xml_attribute block_attributes[] = {
+ { "begin", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
+ { "end", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
+ { NULL, GDB_XML_AF_NONE, NULL, NULL }
+};
+
+static const struct gdb_xml_attribute btrace_attributes[] = {
+ { "version", GDB_XML_AF_NONE, NULL, NULL },
+ { NULL, GDB_XML_AF_NONE, NULL, NULL }
+};
+
+static const struct gdb_xml_element btrace_children[] = {
+ { "block", block_attributes, NULL,
+ GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL, parse_xml_btrace_block, NULL },
+ { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
+};
+
+static const struct gdb_xml_element btrace_elements[] = {
+ { "btrace", btrace_attributes, btrace_children, GDB_XML_EF_NONE,
+ check_xml_btrace_version, NULL },
+ { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
+};
+
+#endif /* defined (HAVE_LIBEXPAT) */
+
+/* See btrace.h. */
+
+VEC (btrace_block_s) *
+parse_xml_btrace (const char *buffer)
+{
+ VEC (btrace_block_s) *btrace = NULL;
+ struct cleanup *cleanup;
+ int errcode;
+
+#if defined (HAVE_LIBEXPAT)
+
+ cleanup = make_cleanup (VEC_cleanup (btrace_block_s), &btrace);
+ errcode = gdb_xml_parse_quick (_("btrace"), "btrace.dtd", btrace_elements,
+ buffer, &btrace);
+ if (errcode != 0)
+ error (_("Error parsing branch trace."));
+
+ /* Keep parse results. */
+ discard_cleanups (cleanup);
+
+#else /* !defined (HAVE_LIBEXPAT) */
+
+ error (_("Cannot process branch trace. XML parsing is not supported."));
+
+#endif /* !defined (HAVE_LIBEXPAT) */
+
+ 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;
+}
+
+/* See btrace.h. */
+
+int
+btrace_is_replaying (struct thread_info *tp)
+{
+ return tp->btrace.replay != NULL;
+}
+
+/* See btrace.h. */
+
+int
+btrace_is_empty (struct thread_info *tp)
+{
+ struct btrace_insn_iterator begin, end;
+ struct btrace_thread_info *btinfo;
+
+ btinfo = &tp->btrace;
+
+ if (btinfo->begin == NULL)
+ return 1;
+
+ btrace_insn_begin (&begin, btinfo);
+ btrace_insn_end (&end, btinfo);
+
+ return btrace_insn_cmp (&begin, &end) == 0;
}