diagnostics: support multithreaded diagnostic paths

This patch extends the existing diagnostic_path class so that as well
as list of events, there is a list of named threads, with each event
being associated with one of the threads.

No GCC diagnostics take advantage of this, but GCC plugins may find a
use for this; an example is provided in the testsuite.

Given that there is still a single list of events within a
diagnostic_path, the events in a diagnostic_path have a specific global
ordering even if they are in multiple threads.

Within the SARIF serialization, the patch adds the "executionOrder"
property to threadFlowLocation objects (SARIF v2.1.0 3.38.11).  This is
1-based in order to match the human-readable numbering of events shown
in messages emitted by pretty-printer.cc's "%@".

With -fdiagnostics-path-format=separate-events, the threads are not
shown.

With -fdiagnostics-path-format=inline-events, the threads and the
per-thread stack activity are tracked and visalized separately.  An
example can be seen in the testsuite.

gcc/analyzer/ChangeLog:
	* checker-event.h (checker_event::get_thread_id): New.
	* checker-path.h (class checker_path): Implement thread-related
	vfuncs via a single simple_diagnostic_thread instance named
	"main".

gcc/ChangeLog:
	* diagnostic-event-id.h (diagnostic_thread_id_t): New typedef.
	* diagnostic-format-sarif.cc (class sarif_thread_flow): New.
	(sarif_thread_flow::sarif_thread_flow): New.
	(sarif_builder::make_code_flow_object): Reimplement, creating
	per-thread threadFlow objects, populating them with the relevant
	events.
	(sarif_builder::make_thread_flow_object): Delete, moving the
	code into sarif_builder::make_code_flow_object.
	(sarif_builder::make_thread_flow_location_object): Add
	"path_event_idx" param.  Use it to set "executionOrder"
	property.
	* diagnostic-path.h (diagnostic_event::get_thread_id): New
	pure-virtual vfunc.
	(class diagnostic_thread): New.
	(diagnostic_path::num_threads): New pure-virtual vfunc.
	(diagnostic_path::get_thread):  New pure-virtual vfunc.
	(diagnostic_path::multithreaded_p): New decl.
	(simple_diagnostic_event::simple_diagnostic_event): Add optional
	thread_id param.
	(simple_diagnostic_event::get_thread_id): New accessor.
	(simple_diagnostic_event::m_thread_id): New.
	(class simple_diagnostic_thread): New.
	(simple_diagnostic_path::simple_diagnostic_path): Move definition
	to diagnostic.cc.
	(simple_diagnostic_path::num_threads): New.
	(simple_diagnostic_path::get_thread): New.
	(simple_diagnostic_path::add_thread): New.
	(simple_diagnostic_path::add_thread_event): New.
	(simple_diagnostic_path::m_threads): New.
	* diagnostic-show-locus.cc (layout::layout): Add pretty_printer
	param for overriding the context's printer.
	(diagnostic_show_locus): Likwise.
	* diagnostic.cc (simple_diagnostic_path::simple_diagnostic_path):
	Move here from diagnostic-path.h.  Add main thread.
	(simple_diagnostic_path::num_threads): New.
	(simple_diagnostic_path::get_thread): New.
	(simple_diagnostic_path::add_thread): New.
	(simple_diagnostic_path::add_thread_event): New.
	(simple_diagnostic_event::simple_diagnostic_event): Add thread_id
	param and use it to initialize m_thread_id.  Reformat.
	* diagnostic.h: Add pretty_printer param for overriding the
	context's printer.
	* tree-diagnostic-path.cc: Add #define INCLUDE_VECTOR.
	(can_consolidate_events): Compare thread ids.
	(class per_thread_summary): New.
	(event_range::event_range): Add per_thread_summary arg.
	(event_range::print): Add "pp" param and use it rather than dc's
	printer.
	(event_range::m_thread_id): New field.
	(event_range::m_per_thread_summary): New field.
	(path_summary::multithreaded_p): New.
	(path_summary::get_events_for_thread_id): New.
	(path_summary::m_per_thread_summary): New field.
	(path_summary::m_thread_id_to_events): New field.
	(path_summary::get_or_create_events_for_thread_id): New.
	(path_summary::path_summary): Create per_thread_summary instances
	as needed and associate the event_range instances with them.
	(base_indent): Move here from print_path_summary_as_text.
	(per_frame_indent): Likewise.
	(class thread_event_printer): New, adapted from parts of
	print_path_summary_as_text.
	(print_path_summary_as_text): Make static.  Reimplement to
	moving most of existing code to class thread_event_printer,
	capturing state as per-thread as appropriate.
	(default_tree_diagnostic_path_printer): Add missing 'break' on
	final case.

gcc/testsuite/ChangeLog:
	* gcc.dg/plugin/diagnostic-test-paths-multithreaded-inline-events.c:
	New test.
	* gcc.dg/plugin/diagnostic-test-paths-multithreaded-sarif.c: New
	test.
	* gcc.dg/plugin/diagnostic-test-paths-multithreaded-separate-events.c:
	New test.
	* gcc.dg/plugin/diagnostic_plugin_test_paths.c: Add support for
	generating multithreaded paths.
	* gcc.dg/plugin/plugin.exp: Add the new tests.

Signed-off-by: David Malcolm <dmalcolm@redhat.com>

1 files changed, 52 insertions, 3 deletions

diff --git a/gcc/diagnostic-path.h b/gcc/diagnostic-path.h
index 9d9d629..d39872a 100644
--- a/gcc/diagnostic-path.h
+++ b/gcc/diagnostic-path.h
@@ -155,6 +155,20 @@ class diagnostic_event
   virtual const logical_location *get_logical_location () const = 0;
 
   virtual meaning get_meaning () const = 0;
+
+  virtual diagnostic_thread_id_t get_thread_id () const = 0;
+};
+
+/* Abstract base class representing a thread of execution within
+   a diagnostic_path.
+   Each diagnostic_event is associated with one thread.
+   Typically there is just one thread per diagnostic_path. */
+
+class diagnostic_thread
+{
+public:
+  virtual ~diagnostic_thread () {}
+  virtual label_text get_name (bool can_colorize) const = 0;
 };
 
 /* Abstract base class for getting at a sequence of events.  */
@@ -165,8 +179,12 @@ class diagnostic_path
   virtual ~diagnostic_path () {}
   virtual unsigned num_events () const = 0;
   virtual const diagnostic_event & get_event (int idx) const = 0;
+  virtual unsigned num_threads () const = 0;
+  virtual const diagnostic_thread &
+  get_thread (diagnostic_thread_id_t) const = 0;
 
   bool interprocedural_p () const;
+  bool multithreaded_p () const;
 
 private:
   bool get_first_event_in_a_function (unsigned *out_idx) const;
@@ -180,7 +198,8 @@ class simple_diagnostic_event : public diagnostic_event
 {
  public:
   simple_diagnostic_event (location_t loc, tree fndecl, int depth,
-			   const char *desc);
+			   const char *desc,
+			   diagnostic_thread_id_t thread_id = 0);
   ~simple_diagnostic_event ();
 
   location_t get_location () const final override { return m_loc; }
@@ -198,12 +217,32 @@ class simple_diagnostic_event : public diagnostic_event
   {
     return meaning ();
   }
+  diagnostic_thread_id_t get_thread_id () const final override
+  {
+    return m_thread_id;
+  }
 
  private:
   location_t m_loc;
   tree m_fndecl;
   int m_depth;
   char *m_desc; // has been i18n-ed and formatted
+  diagnostic_thread_id_t m_thread_id;
+};
+
+/* A simple implementation of diagnostic_thread.  */
+
+class simple_diagnostic_thread : public diagnostic_thread
+{
+public:
+  simple_diagnostic_thread (const char *name) : m_name (name) {}
+  label_text get_name (bool) const final override
+  {
+    return label_text::borrow (m_name);
+  }
+
+private:
+  const char *m_name; // has been i18n-ed and formatted
 };
 
 /* A simple implementation of diagnostic_path, as a vector of
@@ -212,17 +251,27 @@ class simple_diagnostic_event : public diagnostic_event
 class simple_diagnostic_path : public diagnostic_path
 {
  public:
-  simple_diagnostic_path (pretty_printer *event_pp)
-  : m_event_pp (event_pp) {}
+  simple_diagnostic_path (pretty_printer *event_pp);
 
   unsigned num_events () const final override;
   const diagnostic_event & get_event (int idx) const final override;
+  unsigned num_threads () const final override;
+  const diagnostic_thread &
+  get_thread (diagnostic_thread_id_t) const final override;
+
+  diagnostic_thread_id_t add_thread (const char *name);
 
   diagnostic_event_id_t add_event (location_t loc, tree fndecl, int depth,
 				   const char *fmt, ...)
     ATTRIBUTE_GCC_DIAG(5,6);
+  diagnostic_event_id_t
+  add_thread_event (diagnostic_thread_id_t thread_id,
+		    location_t loc, tree fndecl, int depth,
+		    const char *fmt, ...)
+    ATTRIBUTE_GCC_DIAG(6,7);
 
  private:
+  auto_delete_vec<simple_diagnostic_thread> m_threads;
   auto_delete_vec<simple_diagnostic_event> m_events;
 
   /* (for use by add_event).  */