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

[Keith Seitz <keiths@redhat.com>]

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);