GCOV: introduce --json-format.

2018-10-29  Martin Liska  <mliska@suse.cz>

	* Makefile.in: Make dependency to json.o.
	* doc/gcov.texi: Document new JSON format, remove
	old intermediate format documentation.
	* gcov.c (struct function_info): Come up with m_name and
	m_demangled_name.
	(function_info::function_info): Initialize it.
	(function_info::~function_info): Release it.
	(main): Rename flag_intermediate_format to flag_json_format.
	(print_usage): Describe --json-format.
	(process_args): Set flag_json_format.
	(output_intermediate_line): Remove.
	(output_intermediate_json_line): Likewise.
	(get_gcov_intermediate_filename): Return new extension
	".gcov.json.gz".
	(output_intermediate_file): Implement JSON emission.
	(output_json_intermediate_file): Implement JSON emission.
	(generate_results): Use ::get_name for function name.
	Handle JSON output file.
	(read_graph_file): Use ::get_name instead of cplus_demangle.
	(read_count_file): Likewise.
	(solve_flow_graph): Likewise.
	(add_line_counts): Likewise.
	(accumulate_line_counts): Use new flag_json_format.
	(output_function_details): Use ::get_name instead of cplus_demangle.
	(output_lines): Likewise.
	* json.cc (test_writing_literals): Add new tests.
	* json.h (class literal): Add new boolean constructor.
2018-10-29  Martin Liska  <mliska@suse.cz>

	* g++.dg/gcov/gcov-8.C: Do not check intermediate format.
	* lib/gcov.exp: Remove legacy verify-intermediate.

From-SVN: r265587

1 files changed, 128 insertions, 65 deletions

diff --git a/gcc/doc/gcov.texi b/gcc/doc/gcov.texi
index 3b1b38a..8046fd7 100644
--- a/gcc/doc/gcov.texi
+++ b/gcc/doc/gcov.texi
@@ -124,7 +124,7 @@ gcov [@option{-v}|@option{--version}] [@option{-h}|@option{--help}]
      [@option{-c}|@option{--branch-counts}]
      [@option{-d}|@option{--display-progress}]
      [@option{-f}|@option{--function-summaries}]
-     [@option{-i}|@option{--intermediate-format}]
+     [@option{-i}|@option{--json-format}]
      [@option{-j}|@option{--human-readable}]
      [@option{-k}|@option{--use-colors}]
      [@option{-l}|@option{--long-file-names}]
@@ -181,79 +181,142 @@ Display help about using @command{gcov} (on the standard output), and
 exit without doing any further processing.
 
 @item -i
-@itemx --intermediate-format
-Output gcov file in an easy-to-parse intermediate text format that can
-be used by @command{lcov} or other tools. The output is a single
-@file{.gcov} file per @file{.gcda} file. No source code is required.
+@itemx --json-format
+Output gcov file in an easy-to-parse JSON intermediate format
+which does not require source code for generation.  The JSON
+file is compressed with gzip compression algorithm
+and the files have @file{.gcov.json.gz} extension.
 
-The format of the intermediate @file{.gcov} file is plain text with
-one entry per line
+Structure of the JSON is following:
 
 @smallexample
-version:@var{gcc_version}
-cwd:@var{working_directory}
-file:@var{source_file_name}
-function:@var{start_line_number},@var{end_line_number},@var{execution_count},@var{function_name}
-lcount:@var{line number},@var{execution_count},@var{has_unexecuted_block}
-branch:@var{line_number},@var{branch_coverage_type}
-
-Where the @var{branch_coverage_type} is
-   notexec (Branch not executed)
-   taken (Branch executed and taken)
-   nottaken (Branch executed, but not taken)
+@{
+  "current_working_directory": @var{current_working_directory},
+  "format_version": @var{format_version},
+  "gcc_version": @var{gcc_version}
+  "files": [@var{file}]
+@}
 @end smallexample
 
-There can be multiple @var{file} entries in an intermediate gcov
-file. All entries following a @var{file} pertain to that source file
-until the next @var{file} entry.  If there are multiple functions that
-start on a single line, then corresponding lcount is repeated multiple
-times.
+Fields of the root element have following semantics:
 
-Here is a sample when @option{-i} is used in conjunction with @option{-b} option:
+@itemize @bullet
+@item
+@var{current_working_directory}: working directory where
+a compilation unit was compiled
+
+@item
+@var{format_version}: semantic version of the format
+
+@item
+@var{gcc_version}: version of the GCC compiler
+@end itemize
+
+Each @var{file} has the following form:
+
+@smallexample
+@{
+  "file": @var{file_name},
+  "functions": [@var{function}],
+  "lines": [@var{line}]
+@}
+@end smallexample
+
+Fields of the @var{file} element have following semantics:
+
+@itemize @bullet
+@item
+@var{file_name}: name of the source file
+@end itemize
+
+Each @var{function} has the following form:
+
+@smallexample
+@{
+  "blocks": @var{blocks},
+  "blocks_executed": @var{blocks_executed},
+  "demangled_name": "@var{demangled_name},
+  "end_line": @var{end_line},
+  "execution_count": @var{execution_count},
+  "name": @var{name},
+  "start_line": @var{start_line}
+@}
+@end smallexample
+
+Fields of the @var{function} element have following semantics:
+
+@itemize @bullet
+@item
+@var{blocks}: number of blocks that are in the function
+
+@item
+@var{blocks_executed}: number of executed blocks of the function
+
+@item
+@var{demangled_name}: demangled name of the function
+
+@item
+@var{end_line}: line in the source file where the function ends
+
+@item
+@var{execution_count}: number of executions of the function
+
+@item
+@var{name}: name of the function
+
+@item
+@var{start_line}: line in the source file where the function begins
+@end itemize
+
+Each @var{line} has the following form:
+
+@smallexample
+@{
+  "branches": [@var{branch}],
+  "count": @var{count},
+  "line_number": @var{line_number},
+  "unexecuted_block": @var{unexecuted_block}
+@}
+@end smallexample
+
+Branches are present only with @var{-b} option.
+Fields of the @var{line} element have following semantics:
+
+@itemize @bullet
+@item
+@var{count}: number of executions of the line
+
+@item
+@var{line_number}: line number
+
+@item
+@var{unexecuted_block}: flag whether the line contains an unexecuted block
+(not all statements on the line are executed)
+@end itemize
+
+Each @var{branch} has the following form:
 
 @smallexample
-version: 8.1.0 20180103
-cwd:/home/gcc/testcase
-file:tmp.cpp
-function:7,7,0,_ZN3FooIcEC2Ev
-function:7,7,1,_ZN3FooIiEC2Ev
-function:8,8,0,_ZN3FooIcE3incEv
-function:8,8,2,_ZN3FooIiE3incEv
-function:18,37,1,main
-lcount:7,0,1
-lcount:7,1,0
-lcount:8,0,1
-lcount:8,2,0
-lcount:18,1,0
-lcount:21,1,0
-branch:21,taken
-branch:21,nottaken
-lcount:23,1,0
-branch:23,taken
-branch:23,nottaken
-lcount:24,1,0
-branch:24,taken
-branch:24,nottaken
-lcount:25,1,0
-lcount:27,11,0
-branch:27,taken
-branch:27,taken
-lcount:28,10,0
-lcount:30,1,1
-branch:30,nottaken
-branch:30,taken
-lcount:32,1,0
-branch:32,nottaken
-branch:32,taken
-lcount:33,0,1
-branch:33,notexec
-branch:33,notexec
-lcount:35,1,0
-branch:35,taken
-branch:35,nottaken
-lcount:36,1,0
+@{
+  "count": @var{count},
+  "fallthrough": @var{fallthrough},
+  "throw": @var{throw}
+@}
 @end smallexample
 
+Fields of the @var{branch} element have following semantics:
+
+@itemize @bullet
+@item
+@var{count}: number of executions of the branch
+
+@item
+@var{fallthrough}: true when the branch is a fall through branch
+
+@item
+@var{throw}: true when the branch is an exceptional branch
+@end itemize
+
 @item -j
 @itemx --human-readable
 Write counts in human readable format (like 24.6k).
@@ -842,7 +905,7 @@ some summary information.
 
 It is not recommended to access the coverage files directly.
 Consumers should use the intermediate format that is provided
-by @command{gcov} tool via @option{--intermediate-format} option.
+by @command{gcov} tool via @option{--json-format} option.
 
 @node Cross-profiling
 @section Data File Relocation to Support Cross-Profiling