* Add coverage measurement constant COVERAGE__. This constant is not

for casual use.  Usage: (1) assign {} to COVERAGE__, (2) require or
  load Ruby source file, and (3) COVERAGE__["sourcefilepath"] will
  return an array whose elements represent number of executions per
  line of source code.

* vm_core.h: add field of coverage array to iseq.

* iseq.c (prepare_iseq_build): ditto.

* insns.def (trace): update coverage array.

* parse.y (coverage): create and initialize coverage array.

* compile.h (ADD_TRACE): add trace instruction to update covearge
  array.

* thread.c (clear_coverage): delete coverage array when forking.
  Otherwise, double count of coverage may occur.

* lib/coverage.rb: sample coverage measurement tool.

* error.c: distinguish explicitly between parse_in_eval and
  mild_compile_error.

* load.c: ditto.

* vm_eval.c: ditto.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@17781 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/coverage.rb

@@ -0,0 +1,57 @@
+COVERAGE__ ||= {}
+ext = ENV["COVERUBY_EXT"] || ".cov"
+accum = ENV["COVERUBY_ACCUM"]
+accum = !accum || accum == "" || !(%w(f n 0).include?(accum[0]))
+pwd = Dir.pwd
+
+at_exit do
+  Dir.chdir(pwd) do
+    COVERAGE__.each do |sfile, covs|
+      cfile = sfile + ext
+
+      writable = proc do |f|
+        File.writable?(f) || File.writable?(File.dirname(f))
+      end
+      unless writable[cfile]
+        cfile = cfile.gsub(File.PATH_SEPARATOR, "#")
+        next unless writable[cfile]
+      end
+
+      readlines = proc do |f|
+        File.read(f).force_encoding("ASCII-8BIT").lines.to_a
+      end
+
+      sources = (readlines[sfile] rescue [])
+
+      pcovs = []
+      if accum
+        pcovs = (readlines[cfile] rescue []).map.with_index do |line, idx|
+          if line[/^\s*(?:(#####)|(\d+)|-):\s*\d+:(.*)$/n]
+            cov, line = $1 ? 0 : ($2 ? $2.to_i : nil), $3
+            if !sources[idx] || sources[idx].chomp != line.chomp
+              warn("source file changed, ignoring: `#{ cfile }'")
+              break []
+            end
+            cov
+          else
+	    p line
+            warn("coverage file corrupted, ignoring: #{ cfile }")
+            break []
+          end
+        end
+        unless pcovs.empty? || pcovs.size == covs.size
+          warn("coverage file changed, ignoring: `#{ cfile }'")
+          pcovs = []
+        end
+      end
+
+      open(cfile, "w") do |out|
+        covs.zip(sources, pcovs).each_with_index do |(cov, line, pcov), idx|
+          cov += pcov || 0 if cov
+          cov = (cov ? (cov == 0 ? "#####" : cov.to_s) : "-").rjust(9)
+          out.puts("%s:% 5d:%s" % [cov, idx + 1, line])
+        end
+      end
+    end
+  end
+end