[PATCH 04/12] gdb: add breakpoint "has locations" methods

[Simon Marchi <simon.marchi@efficios.com>]

Add three convenience methods to struct breakpoint:

 - has_locations: returns true if the breakpoint has at least one
   location
 - has_single_location: returns true if the breakpoint has exactly one
   location
 - has_multiple_locations: returns true if the breakpoint has more than
   one location

A subsequent patch changes the list of breakpoints to be an
intrusive_list, so all these spots would need to change.  But in any
case, I think that this:

  if (b->has_multiple_locations ())

conveys the intention better than:

  if (b->loc != nullptr && b->loc->next != nullptr)

Change-Id: Ib18c3605fd35d425ef9df82cb7aacff1606c6747
---
 gdb/ada-lang.c        |  2 +-
 gdb/breakpoint.c      | 62 +++++++++++++++++++++++--------------------
 gdb/breakpoint.h      | 12 +++++++++
 gdb/elfread.c         |  4 +--
 gdb/tracectf.c        |  2 +-
 gdb/tracefile-tfile.c |  2 +-
 gdb/tracefile.c       |  4 +--
 gdb/tracepoint.c      |  2 +-
 8 files changed, 53 insertions(+), 37 deletions(-)

diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c
index d7316c845d6d..207d58e80a63 100644
--- a/gdb/ada-lang.c
+++ b/gdb/ada-lang.c
@@ -12204,7 +12204,7 @@ create_excep_cond_exprs (struct ada_catchpoint *c,
     return;
 
   /* Same if there are no locations... */
-  if (c->loc == NULL)
+  if (!c->has_locations ())
     return;
 
   /* Compute the condition expression in text form, from the specific
diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index 0ca4528faef2..fefe18644cf9 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -818,7 +818,7 @@ has_multiple_locations (int num)
 {
   for (breakpoint *b : all_breakpoints ())
     if (b->number == num)
-      return b->loc != nullptr && b->loc->next != nullptr;
+      return b->has_multiple_locations ();
 
   return false;
 }
@@ -1876,7 +1876,7 @@ static void
 add_dummy_location (struct breakpoint *b,
 		    struct program_space *pspace)
 {
-  gdb_assert (b->loc == NULL);
+  gdb_assert (!b->has_locations ());
 
   b->loc = new bp_location (b, bp_loc_other);
   b->loc->pspace = pspace;
@@ -2241,7 +2241,7 @@ update_watchpoint (struct watchpoint *b, bool reparse)
 	 above left it without any location set up.  But,
 	 bpstat_stop_status requires a location to be able to report
 	 stops, so make sure there's at least a dummy one.  */
-      if (b->type == bp_watchpoint && b->loc == NULL)
+      if (b->type == bp_watchpoint && !b->has_locations ())
 	add_dummy_location (b, frame_pspace);
     }
   else if (!within_current_scope)
@@ -4106,7 +4106,7 @@ breakpoint_init_inferior (enum inf_context context)
 
   for (breakpoint *b : all_breakpoints_safe ())
     {
-      if (b->loc && b->loc->pspace != pspace)
+      if (b->has_locations () && b->loc->pspace != pspace)
 	continue;
 
       switch (b->type)
@@ -4520,7 +4520,7 @@ bpstat_locno (const bpstat *bs)
 
   int locno = 0;
 
-  if (b != nullptr && b->loc != nullptr && b->loc->next != nullptr)
+  if (b != nullptr && b->has_multiple_locations ())
     {
       const bp_location *bl_i;
 
@@ -6054,7 +6054,9 @@ bool
 bpstat_should_step ()
 {
   for (breakpoint *b : all_breakpoints ())
-    if (breakpoint_enabled (b) && b->type == bp_watchpoint && b->loc != NULL)
+    if (breakpoint_enabled (b)
+	&& b->type == bp_watchpoint
+	&& b->has_locations ())
       return true;
 
   return false;
@@ -6357,10 +6359,11 @@ print_one_breakpoint_location (struct breakpoint *b,
   /* See comment in print_one_breakpoint concerning treatment of
      breakpoints with single disabled location.  */
   if (loc == NULL 
-      && (b->loc != NULL 
-	  && (b->loc->next != NULL
+      && (b->has_locations ()
+	  && (b->has_multiple_locations ()
 	      || !b->loc->enabled || b->loc->disabled_by_cond)))
     header_of_multiple = true;
+
   if (loc == NULL)
     loc = b->loc;
 
@@ -6451,7 +6454,7 @@ print_one_breakpoint_location (struct breakpoint *b,
 	      if (header_of_multiple)
 		uiout->field_string ("addr", "<MULTIPLE>",
 				     metadata_style.style ());
-	      else if (b->loc == NULL || loc->shlib_disabled)
+	      else if (!b->has_locations () || loc->shlib_disabled)
 		uiout->field_string ("addr", "<PENDING>",
 				     metadata_style.style ());
 	      else
@@ -6461,7 +6464,7 @@ print_one_breakpoint_location (struct breakpoint *b,
 	  annotate_field (5);
 	  if (!header_of_multiple)
 	    print_breakpoint_location (b, loc);
-	  if (b->loc)
+	  if (b->has_locations ())
 	    *last_loc = b->loc;
 	}
     }
@@ -6740,9 +6743,10 @@ print_one_breakpoint (breakpoint *b, const bp_location **last_loc, int allflag)
 	  && (!is_catchpoint (b) || is_exception_catchpoint (b)
 	      || is_ada_exception_catchpoint (b))
 	  && (allflag
-	      || (b->loc && (b->loc->next
-			     || !b->loc->enabled
-			     || b->loc->disabled_by_cond))))
+	      || (b->has_locations ()
+		  && (b->has_multiple_locations ()
+		      || !b->loc->enabled
+		      || b->loc->disabled_by_cond))))
 	{
 	  gdb::optional<ui_out_emit_list> locations_list;
 
@@ -6805,7 +6809,7 @@ user_breakpoint_p (struct breakpoint *b)
 int
 pending_breakpoint_p (struct breakpoint *b)
 {
-  return b->loc == NULL;
+  return !b->has_locations ();
 }
 
 /* Print information on breakpoints (including watchpoints and tracepoints).
@@ -7482,8 +7486,9 @@ set_breakpoint_location_function (struct bp_location *loc)
 
 	  function_name = loc->msymbol->linkage_name ();
 
-	  if (b->type == bp_breakpoint && b->loc == loc
-	      && loc->next == NULL && b->related_breakpoint == b)
+	  if (b->type == bp_breakpoint
+	      && b->has_single_location ()
+	      && b->related_breakpoint == b)
 	    {
 	      /* Create only the whole new breakpoint of this type but do not
 		 mess more complicated breakpoints with multiple locations.  */
@@ -9374,13 +9379,12 @@ ranged_breakpoint::resources_needed (const struct bp_location *bl)
 enum print_stop_action
 ranged_breakpoint::print_it (const bpstat *bs) const
 {
-  struct bp_location *bl = loc;
   struct ui_out *uiout = current_uiout;
 
   gdb_assert (type == bp_hardware_breakpoint);
 
   /* Ranged breakpoints have only one location.  */
-  gdb_assert (bl && bl->next == NULL);
+  gdb_assert (this->has_single_location ());
 
   annotate_breakpoint (number);
 
@@ -9412,7 +9416,7 @@ ranged_breakpoint::print_one (const bp_location **last_loc) const
   struct ui_out *uiout = current_uiout;
 
   /* Ranged breakpoints have only one location.  */
-  gdb_assert (bl && bl->next == NULL);
+  gdb_assert (this->has_single_location ());
 
   get_user_print_options (&opts);
 
@@ -9939,7 +9943,7 @@ masked_watchpoint::print_it (const bpstat *bs) const
   struct ui_out *uiout = current_uiout;
 
   /* Masked watchpoints have only one location.  */
-  gdb_assert (this->loc && this->loc->next == nullptr);
+  gdb_assert (this->has_single_location ());
 
   annotate_watchpoint (this->number);
   maybe_print_thread_hit_breakpoint (uiout);
@@ -9985,7 +9989,7 @@ void
 masked_watchpoint::print_one_detail (struct ui_out *uiout) const
 {
   /* Masked watchpoints have only one location.  */
-  gdb_assert (loc && loc->next == NULL);
+  gdb_assert (this->has_single_location ());
 
   uiout->text ("\tmask ");
   uiout->field_core_addr ("mask", loc->gdbarch, hw_wp_mask);
@@ -11571,7 +11575,7 @@ code_breakpoint::say_where () const
 
   /* i18n: cagney/2005-02-11: Below needs to be merged into a
      single string.  */
-  if (loc == NULL)
+  if (!this->has_locations ())
     {
       /* For pending locations, the output differs slightly based
 	 on extra_string.  If this is non-NULL, it contains either
@@ -11604,7 +11608,7 @@ code_breakpoint::say_where () const
 	{
 	  /* If there is a single location, we can print the location
 	     more nicely.  */
-	  if (loc->next == NULL)
+	  if (!this->has_multiple_locations ())
 	    {
 	      const char *filename
 		= symtab_to_filename_for_display (loc->symtab);
@@ -11620,7 +11624,7 @@ code_breakpoint::say_where () const
 	    gdb_printf (": %s.", locspec->to_string ());
 	}
 
-      if (loc->next)
+      if (this->has_multiple_locations ())
 	{
 	  struct bp_location *iter = loc;
 	  int n = 0;
@@ -11879,7 +11883,7 @@ ordinary_breakpoint::print_recreate (struct ui_file *fp) const
 
   /* Print out extra_string if this breakpoint is pending.  It might
      contain, for example, conditions that were set by the user.  */
-  if (loc == NULL && extra_string != NULL)
+  if (!this->has_locations () && extra_string != NULL)
     gdb_printf (fp, " %s", extra_string.get ());
 
   print_recreate_thread (fp);
@@ -12867,11 +12871,11 @@ code_breakpoint::location_spec_to_sals (location_spec *locspec,
 	 errors.  */
       if (e.error == NOT_FOUND_ERROR
 	  && (condition_not_parsed
-	      || (loc != NULL
+	      || (this->has_locations ()
 		  && search_pspace != NULL
 		  && loc->pspace != search_pspace)
-	      || (loc && loc->shlib_disabled)
-	      || (loc && loc->pspace->executing_startup)
+	      || (this->has_locations () && loc->shlib_disabled)
+	      || (this->has_locations () && loc->pspace->executing_startup)
 	      || enable_state == bp_disabled))
 	not_found_and_ok = true;
 
@@ -14265,7 +14269,7 @@ save_breakpoints (const char *filename, int from_tty,
       /* If this is a multi-location breakpoint, check if the locations
 	 should be individually disabled.  Watchpoint locations are
 	 special, and not user visible.  */
-      if (!is_watchpoint (tp) && tp->loc && tp->loc->next)
+      if (!is_watchpoint (tp) && tp->has_multiple_locations ())
 	{
 	  int n = 1;
 
diff --git a/gdb/breakpoint.h b/gdb/breakpoint.h
index 80cb91b1a911..2a3a5cf57b83 100644
--- a/gdb/breakpoint.h
+++ b/gdb/breakpoint.h
@@ -633,6 +633,18 @@ struct breakpoint
   /* Allocate a location for this breakpoint.  */
   virtual struct bp_location *allocate_location ();
 
+  /* Return true if this breakpoint has a least one location.  */
+  bool has_locations () const
+  { return this->loc != nullptr; }
+
+  /* Return true if this breakpoint has a single location.  */
+  bool has_single_location () const
+  { return this->loc != nullptr && this->loc->next == nullptr; }
+
+  /* Return true if this breakpoint has multiple locations.  */
+  bool has_multiple_locations () const
+  { return this->loc != nullptr && this->loc->next != nullptr; }
+
   /* Reevaluate a breakpoint.  This is necessary after symbols change
      (e.g., an executable or DSO was loaded, or the inferior just
      started).  */
diff --git a/gdb/elfread.c b/gdb/elfread.c
index 0305bf218946..7169ae8808a8 100644
--- a/gdb/elfread.c
+++ b/gdb/elfread.c
@@ -970,7 +970,7 @@ elf_gnu_ifunc_resolver_stop (code_breakpoint *b)
        b_return = b_return->related_breakpoint)
     {
       gdb_assert (b_return->type == bp_gnu_ifunc_resolver_return);
-      gdb_assert (b_return->loc != NULL && b_return->loc->next == NULL);
+      gdb_assert (b_return->has_single_location ());
       gdb_assert (frame_id_p (b_return->frame_id));
 
       if (b_return->thread == thread_id
@@ -1039,7 +1039,7 @@ elf_gnu_ifunc_resolver_return_stop (code_breakpoint *b)
       b = (code_breakpoint *) b_next;
     }
   gdb_assert (b->type == bp_gnu_ifunc_resolver);
-  gdb_assert (b->loc->next == NULL);
+  gdb_assert (b->has_single_location ());
 
   func_func = value::allocate (func_func_type);
   func_func->set_lval (lval_memory);
diff --git a/gdb/tracectf.c b/gdb/tracectf.c
index d8d0f05d049b..ab513b1fa158 100644
--- a/gdb/tracectf.c
+++ b/gdb/tracectf.c
@@ -1535,7 +1535,7 @@ ctf_get_traceframe_address (void)
       struct tracepoint *tp
 	= get_tracepoint_by_number_on_target (tpnum);
 
-      if (tp && tp->loc)
+      if (tp != nullptr && tp->has_locations ())
 	addr = tp->loc->address;
     }
 
diff --git a/gdb/tracefile-tfile.c b/gdb/tracefile-tfile.c
index 31eb974d4163..9c1adee11bc3 100644
--- a/gdb/tracefile-tfile.c
+++ b/gdb/tracefile-tfile.c
@@ -667,7 +667,7 @@ tfile_get_traceframe_address (off_t tframe_offset)
 
   tp = get_tracepoint_by_number_on_target (tpnum);
   /* FIXME this is a poor heuristic if multiple locations.  */
-  if (tp && tp->loc)
+  if (tp != nullptr && tp->has_locations ())
     addr = tp->loc->address;
 
   /* Restore our seek position.  */
diff --git a/gdb/tracefile.c b/gdb/tracefile.c
index b4543c9bf5fd..883ce4bf375a 100644
--- a/gdb/tracefile.c
+++ b/gdb/tracefile.c
@@ -390,11 +390,11 @@ tracefile_fetch_registers (struct regcache *regcache, int regno)
 
   /* We can often usefully guess that the PC is going to be the same
      as the address of the tracepoint.  */
-  if (tp == NULL || tp->loc == NULL)
+  if (tp == nullptr || !tp->has_locations ())
     return;
 
   /* But don't try to guess if tracepoint is multi-location...  */
-  if (tp->loc->next)
+  if (tp->has_multiple_locations ())
     {
       warning (_("Tracepoint %d has multiple "
 		 "locations, cannot infer $pc"),
diff --git a/gdb/tracepoint.c b/gdb/tracepoint.c
index ffda4a6439e4..4a9d8491a54b 100644
--- a/gdb/tracepoint.c
+++ b/gdb/tracepoint.c
@@ -1522,7 +1522,7 @@ process_tracepoint_on_disconnect (void)
      user that pending tracepoint will no longer work.  */
   for (breakpoint *b : all_tracepoints ())
     {
-      if (b->loc == NULL)
+      if (!b->has_locations ())
 	{
 	  has_pending_p = 1;
 	  break;
-- 
2.40.1