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, 5 insertions, 0 deletions

diff --git a/gcc/diagnostic-event-id.h b/gcc/diagnostic-event-id.h
index 84f4b65..c5f5d60 100644
--- a/gcc/diagnostic-event-id.h
+++ b/gcc/diagnostic-event-id.h
@@ -58,4 +58,9 @@ class diagnostic_event_id_t
    The %@ format code requires that known_p be true for the event ID. */
 typedef diagnostic_event_id_t *diagnostic_event_id_ptr;
 
+/* A type for compactly referring to a particular thread within a
+   diagnostic_path.  Typically there is just one thread per path,
+   with id 0.  */
+typedef unsigned diagnostic_thread_id_t;
+
 #endif /* ! GCC_DIAGNOSTIC_EVENT_ID_H */