Add "-fsave-optimization-record"

This patch implements a -fsave-optimization-record option, which
leads to a JSON file being written out, recording the dump_* calls
made (via the optinfo infrastructure).

The patch includes a minimal version of the JSON patch I posted last
year, with just enough support needed for optimization records (I
removed all of the parser code, leaving just the code for building
in-memory JSON trees and writing them to a pretty_printer).

gcc/ChangeLog:
	* Makefile.in (OBJS): Add json.o and optinfo-emit-json.o.
	(CFLAGS-optinfo-emit-json.o): Define TARGET_NAME.
	* common.opt (fsave-optimization-record): New option.
	* coretypes.h (struct kv_pair): Move here from dumpfile.c.
	* doc/invoke.texi (-fsave-optimization-record): New option.
	* dumpfile.c: Include "optinfo-emit-json.h".
	(struct kv_pair): Move to coretypes.h.
	(optgroup_options): Make non-static.
	(dump_context::end_scope): Call
	optimization_records_maybe_pop_dump_scope.
	* dumpfile.h (optgroup_options): New decl.
	* json.cc: New file.
	* json.h: New file.
	* optinfo-emit-json.cc: New file.
	* optinfo-emit-json.h: New file.
	* optinfo.cc: Include "optinfo-emit-json.h".
	(optinfo::emit): Call optimization_records_maybe_record_optinfo.
	(optinfo_enabled_p): Check optimization_records_enabled_p.
	(optinfo_wants_inlining_info_p): Likewise.
	* optinfo.h: Update comment.
	* profile-count.c (profile_quality_as_string): New function.
	* profile-count.h (profile_quality_as_string): New decl.
	(profile_count::quality): New accessor.
	* selftest-run-tests.c (selftest::run_tests): Call json_cc_tests
	and optinfo_emit_json_cc_tests.
	* selftest.h (selftest::json_cc_tests): New decl.
	(selftest::optinfo_emit_json_cc_tests): New decl.
	* toplev.c: Include "optinfo-emit-json.h".
	(compile_file): Call optimization_records_finish.
	(do_compile): Call optimization_records_start.
	* tree-ssa-live.c: Include optinfo.h.
	(remove_unused_scope_block_p): Retain inlining information if
	optinfo_wants_inlining_info_p returns true.

From-SVN: r262905

1 files changed, 47 insertions, 1 deletions

diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 485f599..9d75edb 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -419,7 +419,8 @@ Objective-C and Objective-C++ Dialects}.
 -freorder-blocks-algorithm=@var{algorithm} @gol
 -freorder-blocks-and-partition  -freorder-functions @gol
 -frerun-cse-after-loop  -freschedule-modulo-scheduled-loops @gol
--frounding-math  -fsched2-use-superblocks  -fsched-pressure @gol
+-frounding-math  -fsave-optimization-record @gol
+-fsched2-use-superblocks  -fsched-pressure @gol
 -fsched-spec-load  -fsched-spec-load-dangerous @gol
 -fsched-stalled-insns-dep[=@var{n}]  -fsched-stalled-insns[=@var{n}] @gol
 -fsched-group-heuristic  -fsched-critical-path-heuristic @gol
@@ -13969,6 +13970,51 @@ the first option takes effect and the subsequent options are
 ignored. Thus only @file{vec.miss} is produced which contains
 dumps from the vectorizer about missed opportunities.
 
+@item -fsave-optimization-record
+@opindex fsave-optimization-record
+Write a SRCFILE.opt-record.json file detailing what optimizations
+were performed, for those optimizations that support @option{-fopt-info}.
+
+This option is experimental and the format of the data within the JSON
+file is subject to change.
+
+It is roughly equivalent to a machine-readable version of
+@option{-fopt-info-all}, as a collection of messages with source file,
+line number and column number, with the following additional data for
+each message:
+
+@itemize @bullet
+
+@item
+the execution count of the code being optimized, along with metadata about
+whether this was from actual profile data, or just an estimate, allowing
+consumers to prioritize messages by code hotness,
+
+@item
+the function name of the code being optimized, where applicable,
+
+@item
+the ``inlining chain'' for the code being optimized, so that when
+a function is inlined into several different places (which might
+themselves be inlined), the reader can distinguish between the copies,
+
+@item
+objects identifying those parts of the message that refer to expressions,
+statements or symbol-table nodes, which of these categories they are, and,
+when available, their source code location,
+
+@item
+the GCC pass that emitted the message, and
+
+@item
+the location in GCC's own code from which the message was emitted
+
+@end itemize
+
+Additionally, some messages are logically nested within other
+messages, reflecting implementation details of the optimization
+passes.
+
 @item -fsched-verbose=@var{n}
 @opindex fsched-verbose
 On targets that use instruction scheduling, this option controls the