leaked-globals: check if un-prefixed symbols leak externally

Makefile.in

@@ -640,3 +640,7 @@ mjit_build_dir.$(SOEXT): $(MJIT_MIN_HEADER) $(srcdir)/ruby-runner.c ruby-runner.
 	$(Q) $(DLDSHARED) $(MJIT_DLDFLAGS) $(ARCH_FLAG) $(CFLAGS) $(CPPFLAGS) \
 		-DMAKE_MJIT_BUILD_DIR=1 -DMJIT_MIN_HEADER='"$(MJIT_MIN_HEADER)"' \
 		$(OUTFLAG)$@ $(srcdir)/ruby-runner.c
+
+# yes-test-basic: leaked-globals
+leaked-globals: $(COMMONOBJS) prog $(srcdir)/tool/leaked-globals PHONY
+	$(Q) $(XRUBY) $(srcdir)/tool/leaked-globals NM=$(NM) SYMBOL_PREFIX=$(SYMBOL_PREFIX) $(srcdir)/configure.ac $(COMMONOBJS)

tool/leaked-globals

@@ -0,0 +1,40 @@
+#!/usr/bin/ruby
+require_relative 'colorize'
+
+until ARGV.empty?
+  case ARGV[0]
+  when /\ASYMBOL_PREFIX=(.*)/
+    SYMBOL_PREFIX = $1
+  when /\ANM=(.*)/              # may be multiple words
+    NM = $1
+  else
+    break
+  end
+  ARGV.shift
+end
+
+config = ARGV.shift
+count = 0
+col = Colorize.new
+REPLACE = File.read(config).scan(/\bAC_(?:REPLACE|CHECK)_FUNCS?\(\K\w+/)
+print "Checking leaked global symbols..."
+STDOUT.flush
+IO.foreach("|#{NM} -Pgp #{ARGV.join(' ')}") do |line|
+  n, t, = line.split
+  next unless /[BDT]/ =~ t
+  next unless n.sub!(/^#{SYMBOL_PREFIX}/o, "")
+  next if n.include?(".")
+  next if /\A(?:Init_|InitVM_|ruby_|rb_|[Oo]nig|st_|dln_|mjit_|coroutine_|nu(?:comp|rat)_)/ =~ n
+  next if REPLACE.include?(n)
+  puts col.fail("leaked") if count.zero?
+  count += 1
+  puts "  #{n}"
+end
+case count
+when 0
+  puts col.pass("none")
+when 1
+  abort col.fail("1 un-prefixed symbol leaked")
+else
+  abort col.fail("#{count} un-prefixed symbols leaked")
+end