Pull Request #731 but with tests (#802)

* proc/eval: fix length calculation for string concatenation

* proc/variable: find package variables when the package has a path

_fixtures/pkgrenames.go

@@ -51,5 +51,5 @@ func main() {
 	m := t.Method(0)
 	fmt.Println(m.Type.In(0))
 	fmt.Println(m.Type.String())
-	fmt.Println(badexpr, req, amap, amap2, dir0someType, dir1someType, amap3, anarray, achan, aslice, afunc, astruct, astruct2, iface2iface, iface3)
+	fmt.Println(badexpr, req, amap, amap2, dir0someType, dir1someType, amap3, anarray, achan, aslice, afunc, astruct, astruct2, iface2iface, iface3, pkg.SomeVar)
 }

_fixtures/vendor/dir0/pkg/main.go

@@ -11,3 +11,5 @@ func (s *SomeType) AMethod(x int) int {
 func (s *SomeType) AnotherMethod(x int) int {
 	return x + 4
 }
+
+var SomeVar SomeType

pkg/proc/eval.go

@@ -850,6 +850,9 @@ func (scope *EvalScope) evalBinary(node *ast.BinaryExpr) (*Variable, error) {
 
 		r := xv.newVariable("", 0, typ)
 		r.Value = rc
+		if r.Kind == reflect.String {
+			r.Len = xv.Len+yv.Len
+		}
 		return r, nil
 	}
 }

pkg/proc/proc_test.go

@@ -2705,3 +2705,28 @@ func TestAttachDetach(t *testing.T) {
 
 	cmd.Process.Kill()
 }
+
+func TestVarSum(t *testing.T) {
+	withTestProcess("testvariables2", t, func(p proc.Process, fixture protest.Fixture) {
+		assertNoError(proc.Continue(p), t, "Continue()")
+		sumvar, err := evalVariable(p, "s1[0] + s1[1]")
+		assertNoError(err, t, "EvalVariable")
+		sumvarstr := constant.StringVal(sumvar.Value)
+		if sumvarstr != "onetwo" {
+			t.Fatalf("s1[0] + s1[1] == %q (expected \"onetwo\")", sumvarstr)
+		}
+		if sumvar.Len != int64(len(sumvarstr)) {
+			t.Fatalf("sumvar.Len == %d (expected %d)", sumvar.Len, len(sumvarstr))
+		}
+	})
+}
+
+func TestPackageWithPathVar(t *testing.T) {
+	withTestProcess("pkgrenames", t, func(p proc.Process, fixture protest.Fixture) {
+		assertNoError(proc.Continue(p), t, "Continue()")
+		_, err := evalVariable(p, "pkg.SomeVar")
+		assertNoError(err, t, "EvalVariable(pkg.SomeVar)")
+		_, err = evalVariable(p, "pkg.SomeVar.X")
+		assertNoError(err, t, "EvalVariable(pkg.SomeVar.X)")
+	})
+}

pkg/proc/variables.go

@@ -657,7 +657,7 @@ func (scope *EvalScope) packageVarAddr(name string) (*Variable, error) {
 			continue
 		}
 
-		if n == name {
+		if n == name || strings.HasSuffix(n, "/"+name) {
 			return scope.extractVarInfoFromEntry(entry, reader)
 		}
 	}