Use lcov visualizer for gcov statistics

This experimental feature is only for Ruby-core team, not for casual users.

Usage: `./configure --enable-gcov && make && make exam && make lcov`

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59262 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

.gitignore

@@ -39,6 +39,7 @@ y.tab.c
 *.gcda
 *.gcno
 *.gcov
+lcov*.info
 
 # /
 /*-fake.rb
@@ -85,6 +86,7 @@ y.tab.c
 /goruby
 /id.[ch]
 /largefile.h
+/lcov-out
 /lex.c
 /libruby*.*
 /miniprelude.c

Makefile.in

@@ -484,6 +484,10 @@ after-update:: prereq
 gcov:
 	$(Q) $(BASERUBY) $(srcdir)/tool/run-gcov.rb
 
+lcov:
+	$(Q) $(BASERUBY) $(srcdir)/tool/run-lcov.rb
+	$(Q) genhtml --ignore-errors source lcov-c-all.info -o lcov-out
+
 update-doclie:
 	$(Q) $(srcdir)/tool/git-refresh -C $(srcdir)/coverage $(Q1:0=-q) \
 		--branch $(DOCLIE_GIT_REF) \

tool/run-lcov.rb

@@ -0,0 +1,41 @@
+#!ruby
+require "pathname"
+require "open3"
+
+def backup_gcda_files(gcda_files)
+  gcda_files = gcda_files.map do |gcda|
+    [gcda, gcda.sub_ext(".bak")]
+  end
+  begin
+    gcda_files.each do |before, after|
+      before.rename(after)
+    end
+    yield
+  ensure
+    gcda_files.each do |before, after|
+      after.rename(before)
+    end
+  end
+end
+
+$info_files = []
+def run_lcov(dir, info)
+  $info_files << info
+  system("lcov", "-c", "-d", dir, "--rc", "lcov_branch_coverage=1", "-o", info)
+end
+
+gcda_files = Pathname.glob("**/*.gcda")
+ext_gcda_files = gcda_files.select {|f| f.fnmatch("ext/*") }
+rubyspec_temp_gcda_files = gcda_files.select {|f| f.fnmatch("rubyspec_temp/*") }
+
+backup_gcda_files(rubyspec_temp_gcda_files) do
+  backup_gcda_files(ext_gcda_files) do
+    info = "lcov-root.info"
+    run_lcov(".", info)
+  end
+  ext_gcda_files.group_by {|f| f.descend.to_a[1] }.each do |key, files|
+    info = "lcov-#{ key.to_s.gsub(File::Separator, "-") }.info"
+    run_lcov(key.to_s, info)
+  end
+end
+system("lcov", *$info_files.flat_map {|f| ["-a", f] }, "-o", "lcov-c-all.info")