gdb: add all_tracepoints function

Same idea as the previous patches, but to replace the ALL_TRACEPOINTS
macro.  Define a new filtered_iterator that only keeps the breakpoints
for which is_tracepoint returns true (just like the macro did).

I would have like to make it so tracepoint_range yields some
`tracepoint *` instead of some `breakpoint *`, that would help simplify
the callers, who wouldn't have to do the cast themselves.  But I didn't
find an obvious way to do it.  It can always be added later.

It turns out there is already an all_tracepoints function, which returns
a vector containing all the breakpoints that are tracepoint.  Remove it,
most users will just work seamlessly with the new function.  The
exception is start_tracing, which iterated multiple times on the vector.
Adapt this one so it iterates multiple times on the returned range.

Since the existing users of all_tracepoints are outside of breakpoint.c,
this requires defining all_tracepoints and a few supporting types in
breakpoint.h.  So, move breakpoint_iterator from breakpoint.c to
breakpoint.h.

gdb/ChangeLog:

	* breakpoint.h (all_tracepoints): Remove.
	(breakpoint_iterator): Move here.
	(struct tracepoint_filter): New.
	(tracepoint_iterator): New.
	(tracepoint_range): New.
	(all_tracepoints): New.
	* breakpoint.c (ALL_TRACEPOINTS): Remove, replace all users with
	all_tracepoints.
	(breakpoint_iterator): Move to header.
	(all_tracepoints): New.
	* tracepoint.c (start_tracing): Adjust.

Change-Id: I76b1bba4215dbec7a03846c568368aeef7f1e05a

4 files changed, 58 insertions, 48 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index d855454..ca6418b 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,19 @@
 2021-05-27  Simon Marchi  <simon.marchi@polymtl.ca>
 
+	* breakpoint.h (all_tracepoints): Remove.
+	(breakpoint_iterator): Move here.
+	(struct tracepoint_filter): New.
+	(tracepoint_iterator): New.
+	(tracepoint_range): New.
+	(all_tracepoints): New.
+	* breakpoint.c (ALL_TRACEPOINTS): Remove, replace all users with
+	all_tracepoints.
+	(breakpoint_iterator): Move to header.
+	(all_tracepoints): New.
+	* tracepoint.c (start_tracing): Adjust.
+
+2021-05-27  Simon Marchi  <simon.marchi@polymtl.ca>
+
 	* breakpoint.c (breakpoint_safe_range): New.
 	(all_breakpoints_safe): New.  Use instead of
 	ALL_BREAKPOINTS_SAFE where possible.
diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index c5aea77..7ada790 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -514,20 +514,10 @@ bool target_exact_watchpoints = false;
 	     && (*BP_LOCP_TMP)->address == ADDRESS);			\
 	     BP_LOCP_TMP++)
 
-/* Iterator for tracepoints only.  */
-
-#define ALL_TRACEPOINTS(B)  \
-  for (B = breakpoint_chain; B; B = B->next)  \
-    if (is_tracepoint (B))
-
 /* Chains of all breakpoints defined.  */
 
 static struct breakpoint *breakpoint_chain;
 
-/* Breakpoint linked list iterator.  */
-
-using breakpoint_iterator = next_iterator<breakpoint>;
-
 /* Breakpoint linked list range.  */
 
 using breakpoint_range = next_adapter<breakpoint, breakpoint_iterator>;
@@ -554,6 +544,14 @@ all_breakpoints_safe ()
   return breakpoint_safe_range (all_breakpoints ());
 }
 
+/* See breakpoint.h.  */
+
+tracepoint_range
+all_tracepoints ()
+{
+  return tracepoint_range (breakpoint_chain);
+}
+
 /* Array is sorted by bp_location_is_less_than - primarily by the ADDRESS.  */
 
 static struct bp_location **bp_locations;
@@ -11714,12 +11712,11 @@ bp_locations_target_extensions_update (void)
 static void
 download_tracepoint_locations (void)
 {
-  struct breakpoint *b;
   enum tribool can_download_tracepoint = TRIBOOL_UNKNOWN;
 
   scoped_restore_current_pspace_and_thread restore_pspace_thread;
 
-  ALL_TRACEPOINTS (b)
+  for (breakpoint *b : all_tracepoints ())
     {
       struct bp_location *bl;
       struct tracepoint *t;
@@ -14910,13 +14907,12 @@ delete_trace_command (const char *arg, int from_tty)
   if (arg == 0)
     {
       int breaks_to_delete = 0;
-      breakpoint *tp;
 
       /* Delete all breakpoints if no argument.
 	 Do not delete internal or call-dummy breakpoints, these
 	 have to be deleted with an explicit breakpoint number 
 	 argument.  */
-      ALL_TRACEPOINTS (tp)
+      for (breakpoint *tp : all_tracepoints ())
 	if (is_tracepoint (tp) && user_breakpoint_p (tp))
 	  {
 	    breaks_to_delete = 1;
@@ -14973,13 +14969,11 @@ trace_pass_command (const char *args, int from_tty)
   args = skip_spaces (args);
   if (*args && strncasecmp (args, "all", 3) == 0)
     {
-      struct breakpoint *b;
-
       args += 3;			/* Skip special argument "all".  */
       if (*args)
 	error (_("Junk at end of arguments."));
 
-      ALL_TRACEPOINTS (b)
+      for (breakpoint *b : all_tracepoints ())
       {
 	t1 = (struct tracepoint *) b;
 	trace_pass_set_count (t1, count, from_tty);
@@ -15006,9 +15000,7 @@ trace_pass_command (const char *args, int from_tty)
 struct tracepoint *
 get_tracepoint (int num)
 {
-  struct breakpoint *t;
-
-  ALL_TRACEPOINTS (t)
+  for (breakpoint *t : all_tracepoints ())
     if (t->number == num)
       return (struct tracepoint *) t;
 
@@ -15022,9 +15014,7 @@ get_tracepoint (int num)
 struct tracepoint *
 get_tracepoint_by_number_on_target (int num)
 {
-  struct breakpoint *b;
-
-  ALL_TRACEPOINTS (b)
+  for (breakpoint *b : all_tracepoints ())
     {
       struct tracepoint *t = (struct tracepoint *) b;
 
@@ -15044,7 +15034,6 @@ struct tracepoint *
 get_tracepoint_by_number (const char **arg,
 			  number_or_range_parser *parser)
 {
-  struct breakpoint *t;
   int tpnum;
   const char *instring = arg == NULL ? NULL : *arg;
 
@@ -15068,7 +15057,7 @@ get_tracepoint_by_number (const char **arg,
       return NULL;
     }
 
-  ALL_TRACEPOINTS (t)
+  for (breakpoint *t : all_tracepoints ())
     if (t->number == tpnum)
     {
       return (struct tracepoint *) t;
@@ -15225,22 +15214,6 @@ save_tracepoints_command (const char *args, int from_tty)
   save_breakpoints (args, from_tty, is_tracepoint);
 }
 
-/* Create a vector of all tracepoints.  */
-
-std::vector<breakpoint *>
-all_tracepoints (void)
-{
-  std::vector<breakpoint *> tp_vec;
-  struct breakpoint *tp;
-
-  ALL_TRACEPOINTS (tp)
-  {
-    tp_vec.push_back (tp);
-  }
-
-  return tp_vec;
-}
-
 
 /* This help string is used to consolidate all the help string for specifying
    locations used by several commands.  */
diff --git a/gdb/breakpoint.h b/gdb/breakpoint.h
index 54c5e42..5a10839 100644
--- a/gdb/breakpoint.h
+++ b/gdb/breakpoint.h
@@ -28,6 +28,7 @@
 #include "location.h"
 #include <vector>
 #include "gdbsupport/array-view.h"
+#include "gdbsupport/filtered-iterator.h"
 #include "gdbsupport/function-view.h"
 #include "gdbsupport/refcounted-object.h"
 #include "cli/cli-script.h"
@@ -1683,9 +1684,6 @@ extern struct tracepoint *
   get_tracepoint_by_number (const char **arg,
 			    number_or_range_parser *parser);
 
-/* Return a vector of all tracepoints currently defined.  */
-extern std::vector<breakpoint *> all_tracepoints (void);
-
 /* Return true if B is of tracepoint kind.  */
 
 extern bool is_tracepoint (const struct breakpoint *b);
@@ -1717,6 +1715,31 @@ public:
 extern struct breakpoint *iterate_over_breakpoints
   (gdb::function_view<bool (breakpoint *)>);
 
+/* Breakpoint linked list iterator.  */
+
+using breakpoint_iterator = next_iterator<breakpoint>;
+
+/* Breakpoint filter to only keep tracepoints.  */
+
+struct tracepoint_filter
+{
+  bool operator() (breakpoint *b)
+  { return is_tracepoint (b); }
+};
+
+/* Breakpoint linked list iterator, filtering to only keep tracepoints.  */
+
+using tracepoint_iterator
+  = filtered_iterator<breakpoint_iterator, tracepoint_filter>;
+
+/* Breakpoint linked list range, filtering to only keep tracepoints.  */
+
+using tracepoint_range = next_adapter<breakpoint, tracepoint_iterator>;
+
+/* Return a range to iterate over all tracepoints.  */
+
+tracepoint_range all_tracepoints ();
+
 /* Nonzero if the specified PC cannot be a location where functions
    have been inlined.  */
 
diff --git a/gdb/tracepoint.c b/gdb/tracepoint.c
index eca1a9d..4f69caf 100644
--- a/gdb/tracepoint.c
+++ b/gdb/tracepoint.c
@@ -1603,13 +1603,13 @@ start_tracing (const char *notes)
   int any_enabled = 0, num_to_download = 0;
   int ret;
 
-  std::vector<breakpoint *> tp_vec = all_tracepoints ();
+  auto tracepoint_range = all_tracepoints ();
 
   /* No point in tracing without any tracepoints...  */
-  if (tp_vec.empty ())
+  if (tracepoint_range.begin () == tracepoint_range.end ())
     error (_("No tracepoints defined, not starting trace"));
 
-  for (breakpoint *b : tp_vec)
+  for (breakpoint *b : tracepoint_range)
     {
       if (b->enable_state == bp_enabled)
 	any_enabled = 1;
@@ -1640,7 +1640,7 @@ start_tracing (const char *notes)
 
   target_trace_init ();
 
-  for (breakpoint *b : tp_vec)
+  for (breakpoint *b : tracepoint_range)
     {
       struct tracepoint *t = (struct tracepoint *) b;
       struct bp_location *loc;