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. */
return SYMBOL_PRINT_NAME (sym);
if (msym != NULL)
- return SYMBOL_PRINT_NAME (msym);
+ return MSYMBOL_PRINT_NAME (msym);
return "<unknown>";
}
/* 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. */
DEBUG ("compute ftrace");
gdbarch = target_gdbarch ();
- begin = NULL;
- end = NULL;
- level = INT_MAX;
+ begin = btinfo->begin;
+ end = btinfo->end;
+ level = begin != NULL ? -btinfo->level : INT_MAX;
blk = VEC_length (btrace_block_s, btrace);
while (blk != 0)
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
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. */
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;
- if (btinfo->target == NULL)
+ 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;
- btrace = target_read_btrace (btinfo->target, BTRACE_READ_NEW);
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 (tp);
+ btrace_clear_history (btinfo);
btrace_compute_ftrace (btinfo, btrace);
}
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;
btinfo->begin = NULL;
btinfo->end = NULL;
- xfree (btinfo->insn_history);
- xfree (btinfo->call_history);
- xfree (btinfo->replay);
-
- btinfo->insn_history = NULL;
- btinfo->call_history = NULL;
- btinfo->replay = NULL;
+ btrace_clear_history (btinfo);
}
/* See btrace.h. */
DEBUG ("free objfile");
- ALL_THREADS (tp)
+ ALL_NON_EXITED_THREADS (tp)
btrace_clear (tp);
}
errcode = gdb_xml_parse_quick (_("btrace"), "btrace.dtd", btrace_elements,
buffer, &btrace);
if (errcode != 0)
- {
- do_cleanups (cleanup);
- return NULL;
- }
+ error (_("Error parsing branch trace."));
/* Keep parse results. */
discard_cleanups (cleanup);
{
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;
+}
projects / platform / upstream / binutils.git / blobdiff