Fix build failure for TestMain in black box test

Fixes #32.

instrumenter.go

@@ -649,6 +649,10 @@ func (i *instrumenter) writeGobcoBlackBox(pkgs []*ast.Package, dstDir string) {
 		"\n" +
 		"func GobcoCover(idx int, cond bool) bool {\n" +
 		"\t" + "return " + pkgName + ".GobcoCover(idx, cond)\n" +
+		"}\n" +
+		"\n" +
+		"func GobcoFinish(code int) int {\n" +
+		"\t" + "return " + pkgName + ".GobcoFinish(code)\n" +
 		"}\n"
 
 	writeFile(filepath.Join(dstDir, "gobco_bridge_test.go"), text)
@@ -700,10 +704,7 @@ func (gen codeGenerator) typeAssertExpr(x string, typ ast.Expr) ast.Expr {
 
 func (gen codeGenerator) callFinish(arg ast.Expr) ast.Expr {
 	return &ast.CallExpr{
-		Fun: &ast.SelectorExpr{
-			X:   gen.ident("gobcoCounts"),
-			Sel: gen.ident("finish"),
-		},
+		Fun:      gen.ident("GobcoFinish"),
 		Lparen:   gen.pos,
 		Args:     []ast.Expr{arg},
 		Ellipsis: token.NoPos,

main_test.go

@@ -470,10 +470,10 @@ func Test_gobcoMain__TestMainTest(t *testing.T) {
 	s := NewSuite(t)
 	defer s.TearDownTest()
 
-	stdout, stderr := s.RunMain(1, "gobco", "-verbose", "testdata/testmaintest")
+	stdout, stderr := s.RunMain(0, "gobco", "-verbose", "testdata/testmaintest")
 
-	s.CheckContains(stdout, "[build failed]")
-	s.CheckContains(stderr, ": undefined: gobcoCounts")
+	s.CheckContains(stdout, "Condition coverage: 1/2")
+	_ = stderr
 }
 
 func Test_gobcoMain__oddeven(t *testing.T) {

templates/gobco_fixed.go

@@ -125,3 +125,8 @@ func (st *gobcoStats) finish(exitCode int) int {
 func GobcoCover(idx int, cond bool) bool {
 	return gobcoCounts.cover(idx, cond)
 }
+
+// GobcoFinish needs to be exported to black-box test packages.
+func GobcoFinish(code int) int {
+	return gobcoCounts.finish(code)
+}

testdata/testmaintest/add.go

@@ -1,5 +1,9 @@
 package add
 
 func Add(x, y int) int {
-	return x + y
+	if x > y {
+		return x + y
+	} else {
+		return y + x
+	}
 }