[PATCH v4 5/9] Explicit locations: introduce probe locations

Keith Seitz
2015-05-07T18:06:02Z

This patch adds support for probe locations and converts existing
probe linespec locations to the new location type.

gdb/ChangeLog:

* break-catch-throw.c (re_set_exception_catchpoint): Convert
linespec for stap probe to probe location.
* breakpoint.c (create_longjmp_master_breakpoint): Likewise.
(create_exception_master_breakpoint): Likewise.
(break_command_1): Remove local variable `arg_cp'.
Check location type to set appropriate breakpoint ops methods.
(trace_command): Likewise.
* linespec.c (event_location_to_sals): Assert on probe locations.
* location.c (EL_PROBE): Add macro definition.
(new_probe_location, get_probe_location): New functions.
(copy_event_location): Handle probe locations.
(delete_event_location): Likewise.
(event_location_to_string): Likewise.
(string_to_event_location): Likewise.
(event_location_empty_p): Likewise.
* location.h (enum event_location_type): Add PROBE_LOCATION.
(new_probe_location, get_probe_location): Declare.
* probe.c (parse_probes): Assert that LOCATION is a probe location.
Convert linespec into probe location.
---
gdb/break-catch-throw.c | 5 ++--
gdb/breakpoint.c | 18 +++++++--------
gdb/linespec.c | 5 ++++
gdb/location.c | 56 +++++++++++++++++++++++++++++++++++++++++++++--
gdb/location.h | 17 +++++++++++++-
gdb/probe.c | 5 +++-
6 files changed, 88 insertions(+), 18 deletions(-)

diff --git a/gdb/break-catch-throw.c b/gdb/break-catch-throw.c
index 9449aa5..07a8f05 100644
--- a/gdb/break-catch-throw.c
+++ b/gdb/break-catch-throw.c
@@ -216,9 +216,8 @@ re_set_exception_catchpoint (struct breakpoint *self)
/* We first try to use the probe interface. */
TRY
{
- char *spec = ASTRDUP (exception_functions[kind].probe);
-
- location = new_linespec_location (&spec);
+ location
+ = new_probe_location (exception_functions[kind].probe);
cleanup = make_cleanup_delete_event_location (location);
sals = parse_probes (location, NULL);
do_cleanups (cleanup);
diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index c1d8ddc..9f879ed 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -3507,7 +3507,6 @@ create_longjmp_master_breakpoint (void)
int i;
struct probe *probe;
struct gdbarch *gdbarch = get_objfile_arch (objfile);
- char *p;

for (i = 0;
VEC_iterate (probe_p,
@@ -3522,8 +3521,8 @@ create_longjmp_master_breakpoint (void)
objfile),
bp_longjmp_master,
&internal_breakpoint_ops);
- p = ASTRDUP ("-probe-stap libc:longjmp");
- b->location = new_linespec_location (&p);
+ b->location
+ = new_probe_location ("-probe-stap libc:longjmp");
b->enable_state = bp_disabled;
}

@@ -3685,15 +3684,14 @@ create_exception_master_breakpoint (void)
++i)
{
struct breakpoint *b;
- char *p;

b = create_internal_breakpoint (gdbarch,
get_probe_address (probe,
objfile),
bp_exception_master,
&internal_breakpoint_ops);
- p = ASTRDUP ("-probe-stap libgcc:unwind");
- b->location = new_linespec_location (&p);
+ b->location
+ = new_probe_location ("-probe-stap libgcc:unwind");
b->enable_state = bp_disabled;
}

@@ -9867,7 +9865,6 @@ break_command_1 (char *arg, int flag, int from_tty)
? bp_hardware_breakpoint
: bp_breakpoint);
struct breakpoint_ops *ops;
- const char *arg_cp = arg;
struct event_location *location;
struct cleanup *cleanup;

@@ -9875,7 +9872,8 @@ break_command_1 (char *arg, int flag, int from_tty)
cleanup = make_cleanup_delete_event_location (location);

/* Matching breakpoints on probes. */
- if (arg_cp != NULL && probe_linespec_to_ops (&arg_cp) != NULL)
+ if (location != NULL
+ && event_location_type (location) == PROBE_LOCATION)
ops = &bkpt_probe_breakpoint_ops;
else
ops = &bkpt_breakpoint_ops;
@@ -14991,11 +14989,11 @@ trace_command (char *arg, int from_tty)
struct breakpoint_ops *ops;
struct event_location *location;
struct cleanup *back_to;
- const char *arg_cp = arg;

location = string_to_event_location (&arg, current_language);
back_to = make_cleanup_delete_event_location (location);
- if (arg_cp != NULL && probe_linespec_to_ops (&arg_cp) != NULL)
+ if (location != NULL
+ && event_location_type (location) == PROBE_LOCATION)
ops = &tracepoint_probe_breakpoint_ops;
else
ops = &tracepoint_breakpoint_ops;
diff --git a/gdb/linespec.c b/gdb/linespec.c
index c4cbe13..fa7e3f4 100644
--- a/gdb/linespec.c
+++ b/gdb/linespec.c
@@ -2486,6 +2486,11 @@ event_location_to_sals (linespec_parser *parser,
get_address_location (location));
break;

+ case PROBE_LOCATION:
+ /* Probes are handled by their own decoders. */
+ gdb_assert_not_reached ("attempt to decode probe location");
+ break;
+
default:
gdb_assert_not_reached ("unhandled event location type");
}
diff --git a/gdb/location.c b/gdb/location.c
index c1f4e19..6059679 100644
--- a/gdb/location.c
+++ b/gdb/location.c
@@ -45,6 +45,7 @@ struct event_location
probes. */
char *addr_string;
#define EL_LINESPEC(PTR) ((PTR)->u.addr_string)
+#define EL_PROBE(PTR) ((PTR)->u.addr_string)

/* An address in the inferior. */
CORE_ADDR address;
@@ -121,6 +122,29 @@ get_address_location (const struct event_location *location)
/* See description in location.h. */

struct event_location *
+new_probe_location (const char *probe)
+{
+ struct event_location *location;
+
+ location = XCNEW (struct event_location);
+ EL_TYPE (location) = PROBE_LOCATION;
+ if (probe != NULL)
+ EL_PROBE (location) = xstrdup (probe);
+ return location;
+}
+
+/* See description in location.h. */
+
+const char *
+get_probe_location (const struct event_location *location)
+{
+ gdb_assert (EL_TYPE (location) == PROBE_LOCATION);
+ return EL_PROBE (location);
+}
+
+/* See description in location.h. */
+
+struct event_location *
copy_event_location (const struct event_location *src)
{
struct event_location *dst;
@@ -141,6 +165,11 @@ copy_event_location (const struct event_location *src)
EL_ADDRESS (dst) = EL_ADDRESS (src);
break;

+ case PROBE_LOCATION:
+ if (EL_PROBE (src) != NULL)
+ EL_PROBE (dst) = xstrdup (EL_PROBE (src));
+ break;
+
default:
gdb_assert_not_reached ("unknown event location type");
}
@@ -185,6 +214,10 @@ delete_event_location (struct event_location *location)
/* Nothing to do. */
break;

+ case PROBE_LOCATION:
+ xfree (EL_PROBE (location));
+ break;
+
default:
gdb_assert_not_reached ("unknown event location type");
}
@@ -216,6 +249,10 @@ event_location_to_string_const (const struct event_location *location)
core_addr_to_string (EL_ADDRESS (location)));
break;

+ case PROBE_LOCATION:
+ result = xstrdup (EL_PROBE (location));
+ break;
+
default:
gdb_assert_not_reached ("unknown event location type");
}
@@ -256,8 +293,20 @@ string_to_event_location (char **stringp,
}
else
{
- /* Everything else is a linespec. */
- location = new_linespec_location (stringp);
+ const char *cs;
+
+ /* Next, try the input as a probe spec. */
+ cs = *stringp;
+ if (cs != NULL && probe_linespec_to_ops (&cs) != NULL)
+ {
+ location = new_probe_location (*stringp);
+ *stringp += strlen (*stringp);
+ }
+ else
+ {
+ /* Everything else is a linespec. */
+ location = new_linespec_location (stringp);
+ }
}

return location;
@@ -277,6 +326,9 @@ event_location_empty_p (const struct event_location *location)
case ADDRESS_LOCATION:
return 0;

+ case PROBE_LOCATION:
+ return EL_PROBE (location) == NULL;
+
default:
gdb_assert_not_reached ("unknown event location type");
}
diff --git a/gdb/location.h b/gdb/location.h
index 39db10e..3112d63 100644
--- a/gdb/location.h
+++ b/gdb/location.h
@@ -31,7 +31,10 @@ enum event_location_type
LINESPEC_LOCATION,

/* An address in the inferior. */
- ADDRESS_LOCATION
+ ADDRESS_LOCATION,
+
+ /* A probe location. */
+ PROBE_LOCATION
};

/* Return the type of the given event location. */
@@ -79,6 +82,18 @@ extern struct event_location *
extern CORE_ADDR
get_address_location (const struct event_location *location);

+/* Create a new probe location. The return result is malloc'd
+ and should be freed with delete_event_location. */
+
+extern struct event_location *
+ new_probe_location (const char *probe);
+
+/* Return the probe location (a string) of the given event_location
+ (which must be of type PROBE_LOCATION). */
+
+extern const char *
+ get_probe_location (const struct event_location *location);
+
/* Free an event location and any associated data. */

extern void delete_event_location (struct event_location *location);
diff --git a/gdb/probe.c b/gdb/probe.c
index 8366220..a3cfefe 100644
--- a/gdb/probe.c
+++ b/gdb/probe.c
@@ -59,7 +59,8 @@ parse_probes (const struct event_location *location,
result.sals = NULL;
result.nelts = 0;

- arg_start = get_linespec_location (location);
+ gdb_assert (event_location_type (location) == PROBE_LOCATION);
+ arg_start = get_probe_location (location);

cs = arg_start;
probe_ops = probe_linespec_to_ops (&cs);
@@ -178,7 +179,7 @@ parse_probes (const struct event_location *location,
make_cleanup (xfree, canon);
canonical->special_display = 1;
canonical->pre_expanded = 1;
- canonical->location = new_linespec_location (&canon);
+ canonical->location = new_probe_location (canon);
}

do_cleanups (cleanup);