diagnostics: add optional CFG dumps to SARIF/HTML output sinks

diagnostics: add optional CFG dumps to SARIF/HTML output sinks

This patch adds a new key/value pair "cfgs={yes,no}" to diagnostics
sinks, "no" by default.

If set to "yes" for a SARIF sink, then GCC will add the internal state
of the CFG for all functions after each pertinent optimization pass in
graph form to theRun.graphs in the SARIF output.

If set to "yes" for an HTML sink, the generated HTML will contain SVG
displaying the graphs, adapted from code in graph.cc

Text sinks ignore it.

The SARIF output is thus a machine-readable serialization of (some of)
GCC's intermediate representation (as JSON), but it's much less than
GCC-XML used to provide.  The precise form of the information is
documented as subject to change without notice.

Currently it shows both gimple statements and RTL instructions,
depending on the pass.  My hope is that it should be possible to write a
"cfg-grep" tool that can read the SARIF and automatically identify
in which pass a particular piece of our IR appeared or disappeared,
for tracking down bugs in our optimization passes.

Implementation-wise:
* this uses the publish-subscribe mechanism from the earlier patch, by
having the diagnostics sink subscribe to pass_events::after_pass
messages from the pass_events_channel.
* the patch adds a new hook to cfghooks.h for dumping a basic block
into a SARIF property bag

gcc/ChangeLog:
	* Makefile.in (OBJS): Add tree-diagnostic-cfg.o.
	(OBJS-libcommon): Add custom-sarif-properties/cfg.o,
	diagnostics/digraphs-to-dot.o, and
	diagnostics/digraphs-to-dot-from-cfg.o.
	* cfghooks.cc: Define INCLUDE_VECTOR.  Add includes of
	"diagnostics/sarif-sink.h" and "custom-sarif-properties/cfg.h".
	(dump_bb_as_sarif_properties): New.
	* cfghooks.h (diagnostics::sarif_builder): New forward decl.
	(json::object): New forward decl.
	(cfg_hooks::dump_bb_as_sarif_properties): New callback field.
	(dump_bb_as_sarif_properties): New decl.
	* cfgrtl.cc (rtl_cfg_hooks): Populate the new callback
	field with rtl_dump_bb_as_sarif_properties.
	(cfg_layout_rtl_cfg_hooks): Likewise.
	* custom-sarif-properties/cfg.cc: New file.
	* custom-sarif-properties/cfg.h: New file.
	* diagnostics/digraphs-to-dot-from-cfg.cc: New file, partly
	adapted from gcc/graph.cc.
	* diagnostics/digraphs-to-dot.cc: New file.
	* diagnostics/digraphs-to-dot.h: New file, based on material in...
	* diagnostics/digraphs.cc: Include
	"diagnostics/digraphs-to-dot.h".
	(class conversion_to_dot): Rework and move to above.
	(make_dot_graph_from_diagnostic_graph): Likewise.
	(make_dot_node_from_digraph_node): Likewise.
	(make_dot_edge_from_digraph_edge): Likewise.
	(conversion_to_dot::get_dot_id_for_node): Likewise.
	(conversion_to_dot::has_edges_p): Likewise.
	(digraph::make_dot_graph): Use to_dot::converter::make and invoke
	the result to make the dot graph.
	* diagnostics/digraphs.h (digraph:get_all_nodes): New accessor.
	* diagnostics/html-sink.cc
	(html_builder::m_per_logical_loc_graphs): New field.
	(html_builder::add_graph_for_logical_loc): New.
	(html_sink::report_digraph_for_logical_location): New.
	* diagnostics/sarif-sink.cc (sarif_array_of_unique::get_element):
	New.
	(sarif_builder::report_digraph_for_logical_location): New.
	(sarif_sink::report_digraph_for_logical_location): New.
	* diagnostics/sink.h: Include "diagnostics/logical-locations.h".
	(sink::report_digraph_for_logical_location): New vfunc.
	* diagnostics/text-sink.h
	(text_sink::report_digraph_for_logical_location): New.
	* doc/invoke.texi (fdiagnostics-add-output): Clarify wording.
	Distinguish between scheme-specific vs GCC-specific keys, and add
	"cfgs" as the first example of the latter.
	* gimple-pretty-print.cc: Include "cfghooks.h", "json.h", and
	"custom-sarif-properties/cfg.h".
	(gimple_dump_bb_as_sarif_properties): New.
	* gimple-pretty-print.h (diagnostics::sarif_builder): New forward
	decl.
	(json::object): Likewise.
	(gimple_dump_bb_as_sarif_properties): New.
	* graphviz.cc (get_compass_pt_from_string): New
	* graphviz.h (get_compass_pt_from_string): New decl.
	* libsarifreplay.cc (sarif_replayer::handle_graph_object): Fix
	overlong line.
	* opts-common.cc: Define INCLUDE_VECTOR.
	* opts-diagnostic.cc: Define INCLUDE_LIST.  Include
	"diagnostics/sarif-sink.h", "tree-diagnostic-sink-extensions.h",
	"opts-diagnostic.h", and "pub-sub.h".
	(class gcc_extra_keys): New class.
	(opt_spec_context::opt_spec_context): Add "client_keys" param and
	pass to dc_spec_context.
	(handle_gcc_specific_keys): New.
	(try_to_make_sink): New.
	(gcc_extension_factory::singleton): New.
	(handle_OPT_fdiagnostics_add_output_): Rework to use
	try_to_make_sink.
	(handle_OPT_fdiagnostics_set_output_): Likewise.
	* opts-diagnostic.h: Include "diagnostics/sink.h".
	(class gcc_extension_factory): New.
	* opts.cc: Define INCLUDE_LIST.
	* print-rtl.cc: Include "dumpfile.h", "cfghooks.h", "json.h", and
	"custom-sarif-properties/cfg.h".
	(rtl_dump_bb_as_sarif_properties): New.
	* print-rtl.h (diagnostics::sarif_builder): New forward decl.
	(json::object): Likewise.
	(rtl_dump_bb_as_sarif_properties): New decl.
	* tree-cfg.cc (gimple_cfg_hooks): Use
	gimple_dump_bb_as_sarif_properties for new callback field.
	* tree-diagnostic-cfg.cc: New file, based on material in graph.cc.
	* tree-diagnostic-sink-extensions.h: New file.
	* tree-diagnostic.cc: Define INCLUDE_LIST.  Include
	"tree-diagnostic-sink-extensions.h".
	(compiler_ext_factory): New.
	(tree_diagnostics_defaults): Set gcc_extension_factory::singleton
	to be compiler_ext_factory.

gcc/testsuite/ChangeLog:
	* gcc.dg/diagnostic-cfgs-html.py: New test.
	* gcc.dg/diagnostic-cfgs-sarif.py: New test.
	* gcc.dg/diagnostic-cfgs.c: New test.

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