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// Copyright 2013 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package ssa_test
// This file defines tests of source-level debugging utilities.
import (
"fmt"
"go/ast"
"go/constant"
"go/parser"
"go/token"
"go/types"
"io/ioutil"
"os"
"runtime"
"strings"
"testing"
"golang.org/x/tools/go/ast/astutil"
"golang.org/x/tools/go/expect"
"golang.org/x/tools/go/loader"
"golang.org/x/tools/go/ssa"
"golang.org/x/tools/go/ssa/ssautil"
)
func TestObjValueLookup(t *testing.T) {
if runtime.GOOS == "android" {
t.Skipf("no testdata directory on %s", runtime.GOOS)
}
conf := loader.Config{ParserMode: parser.ParseComments}
src, err := ioutil.ReadFile("testdata/objlookup.go")
if err != nil {
t.Fatal(err)
}
readFile := func(filename string) ([]byte, error) { return src, nil }
f, err := conf.ParseFile("testdata/objlookup.go", src)
if err != nil {
t.Fatal(err)
}
conf.CreateFromFiles("main", f)
// Maps each var Ident (represented "name:linenum") to the
// kind of ssa.Value we expect (represented "Constant", "&Alloc").
expectations := make(map[string]string)
// Each note of the form @ssa(x, "BinOp") in testdata/objlookup.go
// specifies an expectation that an object named x declared on the
// same line is associated with an an ssa.Value of type *ssa.BinOp.
notes, err := expect.Extract(conf.Fset, f)
if err != nil {
t.Fatal(err)
}
for _, n := range notes {
if n.Name != "ssa" {
t.Errorf("%v: unexpected note type %q, want \"ssa\"", conf.Fset.Position(n.Pos), n.Name)
continue
}
if len(n.Args) != 2 {
t.Errorf("%v: ssa has %d args, want 2", conf.Fset.Position(n.Pos), len(n.Args))
continue
}
ident, ok := n.Args[0].(expect.Identifier)
if !ok {
t.Errorf("%v: got %v for arg 1, want identifier", conf.Fset.Position(n.Pos), n.Args[0])
continue
}
exp, ok := n.Args[1].(string)
if !ok {
t.Errorf("%v: got %v for arg 2, want string", conf.Fset.Position(n.Pos), n.Args[1])
continue
}
p, _, err := expect.MatchBefore(conf.Fset, readFile, n.Pos, string(ident))
if err != nil {
t.Error(err)
continue
}
pos := conf.Fset.Position(p)
key := fmt.Sprintf("%s:%d", ident, pos.Line)
expectations[key] = exp
}
iprog, err := conf.Load()
if err != nil {
t.Error(err)
return
}
prog := ssautil.CreateProgram(iprog, 0 /*|ssa.PrintFunctions*/)
mainInfo := iprog.Created[0]
mainPkg := prog.Package(mainInfo.Pkg)
mainPkg.SetDebugMode(true)
mainPkg.Build()
var varIds []*ast.Ident
var varObjs []*types.Var
for id, obj := range mainInfo.Defs {
// Check invariants for func and const objects.
switch obj := obj.(type) {
case *types.Func:
checkFuncValue(t, prog, obj)
case *types.Const:
checkConstValue(t, prog, obj)
case *types.Var:
if id.Name == "_" {
continue
}
varIds = append(varIds, id)
varObjs = append(varObjs, obj)
}
}
for id, obj := range mainInfo.Uses {
if obj, ok := obj.(*types.Var); ok {
varIds = append(varIds, id)
varObjs = append(varObjs, obj)
}
}
// Check invariants for var objects.
// The result varies based on the specific Ident.
for i, id := range varIds {
obj := varObjs[i]
ref, _ := astutil.PathEnclosingInterval(f, id.Pos(), id.Pos())
pos := prog.Fset.Position(id.Pos())
exp := expectations[fmt.Sprintf("%s:%d", id.Name, pos.Line)]
if exp == "" {
t.Errorf("%s: no expectation for var ident %s ", pos, id.Name)
continue
}
wantAddr := false
if exp[0] == '&' {
wantAddr = true
exp = exp[1:]
}
checkVarValue(t, prog, mainPkg, ref, obj, exp, wantAddr)
}
}
func checkFuncValue(t *testing.T, prog *ssa.Program, obj *types.Func) {
fn := prog.FuncValue(obj)
// fmt.Printf("FuncValue(%s) = %s\n", obj, fn) // debugging
if fn == nil {
if obj.Name() != "interfaceMethod" {
t.Errorf("FuncValue(%s) == nil", obj)
}
return
}
if fnobj := fn.Object(); fnobj != obj {
t.Errorf("FuncValue(%s).Object() == %s; value was %s",
obj, fnobj, fn.Name())
return
}
if !types.Identical(fn.Type(), obj.Type()) {
t.Errorf("FuncValue(%s).Type() == %s", obj, fn.Type())
return
}
}
func checkConstValue(t *testing.T, prog *ssa.Program, obj *types.Const) {
c := prog.ConstValue(obj)
// fmt.Printf("ConstValue(%s) = %s\n", obj, c) // debugging
if c == nil {
t.Errorf("ConstValue(%s) == nil", obj)
return
}
if !types.Identical(c.Type(), obj.Type()) {
t.Errorf("ConstValue(%s).Type() == %s", obj, c.Type())
return
}
if obj.Name() != "nil" {
if !constant.Compare(c.Value, token.EQL, obj.Val()) {
t.Errorf("ConstValue(%s).Value (%s) != %s",
obj, c.Value, obj.Val())
return
}
}
}
func checkVarValue(t *testing.T, prog *ssa.Program, pkg *ssa.Package, ref []ast.Node, obj *types.Var, expKind string, wantAddr bool) {
// The prefix of all assertions messages.
prefix := fmt.Sprintf("VarValue(%s @ L%d)",
obj, prog.Fset.Position(ref[0].Pos()).Line)
v, gotAddr := prog.VarValue(obj, pkg, ref)
// Kind is the concrete type of the ssa Value.
gotKind := "nil"
if v != nil {
gotKind = fmt.Sprintf("%T", v)[len("*ssa."):]
}
// fmt.Printf("%s = %v (kind %q; expect %q) wantAddr=%t gotAddr=%t\n", prefix, v, gotKind, expKind, wantAddr, gotAddr) // debugging
// Check the kinds match.
// "nil" indicates expected failure (e.g. optimized away).
if expKind != gotKind {
t.Errorf("%s concrete type == %s, want %s", prefix, gotKind, expKind)
}
// Check the types match.
// If wantAddr, the expected type is the object's address.
if v != nil {
expType := obj.Type()
if wantAddr {
expType = types.NewPointer(expType)
if !gotAddr {
t.Errorf("%s: got value, want address", prefix)
}
} else if gotAddr {
t.Errorf("%s: got address, want value", prefix)
}
if !types.Identical(v.Type(), expType) {
t.Errorf("%s.Type() == %s, want %s", prefix, v.Type(), expType)
}
}
}
// Ensure that, in debug mode, we can determine the ssa.Value
// corresponding to every ast.Expr.
func TestValueForExpr(t *testing.T) {
testValueForExpr(t, "testdata/valueforexpr.go")
}
func testValueForExpr(t *testing.T, testfile string) {
if runtime.GOOS == "android" {
t.Skipf("no testdata dir on %s", runtime.GOOS)
}
conf := loader.Config{ParserMode: parser.ParseComments}
f, err := conf.ParseFile(testfile, nil)
if err != nil {
t.Error(err)
return
}
conf.CreateFromFiles("main", f)
iprog, err := conf.Load()
if err != nil {
t.Error(err)
return
}
mainInfo := iprog.Created[0]
prog := ssautil.CreateProgram(iprog, 0)
mainPkg := prog.Package(mainInfo.Pkg)
mainPkg.SetDebugMode(true)
mainPkg.Build()
if false {
// debugging
for _, mem := range mainPkg.Members {
if fn, ok := mem.(*ssa.Function); ok {
fn.WriteTo(os.Stderr)
}
}
}
var parenExprs []*ast.ParenExpr
ast.Inspect(f, func(n ast.Node) bool {
if n != nil {
if e, ok := n.(*ast.ParenExpr); ok {
parenExprs = append(parenExprs, e)
}
}
return true
})
notes, err := expect.Extract(prog.Fset, f)
if err != nil {
t.Fatal(err)
}
for _, n := range notes {
want := n.Name
if want == "nil" {
want = "<nil>"
}
position := prog.Fset.Position(n.Pos)
var e ast.Expr
for _, paren := range parenExprs {
if paren.Pos() > n.Pos {
e = paren.X
break
}
}
if e == nil {
t.Errorf("%s: note doesn't precede ParenExpr: %q", position, want)
continue
}
path, _ := astutil.PathEnclosingInterval(f, n.Pos, n.Pos)
if path == nil {
t.Errorf("%s: can't find AST path from root to comment: %s", position, want)
continue
}
fn := ssa.EnclosingFunction(mainPkg, path)
if fn == nil {
t.Errorf("%s: can't find enclosing function", position)
continue
}
v, gotAddr := fn.ValueForExpr(e) // (may be nil)
got := strings.TrimPrefix(fmt.Sprintf("%T", v), "*ssa.")
if got != want {
t.Errorf("%s: got value %q, want %q", position, got, want)
}
if v != nil {
T := v.Type()
if gotAddr {
T = T.Underlying().(*types.Pointer).Elem() // deref
}
if !types.Identical(T, mainInfo.TypeOf(e)) {
t.Errorf("%s: got type %s, want %s", position, mainInfo.TypeOf(e), T)
}
}
}
}
// findInterval parses input and returns the [start, end) positions of
// the first occurrence of substr in input. f==nil indicates failure;
// an error has already been reported in that case.
//
func findInterval(t *testing.T, fset *token.FileSet, input, substr string) (f *ast.File, start, end token.Pos) {
f, err := parser.ParseFile(fset, "<input>", input, 0)
if err != nil {
t.Errorf("parse error: %s", err)
return
}
i := strings.Index(input, substr)
if i < 0 {
t.Errorf("%q is not a substring of input", substr)
f = nil
return
}
filePos := fset.File(f.Package)
return f, filePos.Pos(i), filePos.Pos(i + len(substr))
}
func TestEnclosingFunction(t *testing.T) {
tests := []struct {
input string // the input file
substr string // first occurrence of this string denotes interval
fn string // name of expected containing function
}{
// We use distinctive numbers as syntactic landmarks.
// Ordinary function:
{`package main
func f() { println(1003) }`,
"100", "main.f"},
// Methods:
{`package main
type T int
func (t T) f() { println(200) }`,
"200", "(main.T).f"},
// Function literal:
{`package main
func f() { println(func() { print(300) }) }`,
"300", "main.f$1"},
// Doubly nested
{`package main
func f() { println(func() { print(func() { print(350) })})}`,
"350", "main.f$1$1"},
// Implicit init for package-level var initializer.
{"package main; var a = 400", "400", "main.init"},
// No code for constants:
{"package main; const a = 500", "500", "(none)"},
// Explicit init()
{"package main; func init() { println(600) }", "600", "main.init#1"},
// Multiple explicit init functions:
{`package main
func init() { println("foo") }
func init() { println(800) }`,
"800", "main.init#2"},
// init() containing FuncLit.
{`package main
func init() { println(func(){print(900)}) }`,
"900", "main.init#1$1"},
}
for _, test := range tests {
conf := loader.Config{Fset: token.NewFileSet()}
f, start, end := findInterval(t, conf.Fset, test.input, test.substr)
if f == nil {
continue
}
path, exact := astutil.PathEnclosingInterval(f, start, end)
if !exact {
t.Errorf("EnclosingFunction(%q) not exact", test.substr)
continue
}
conf.CreateFromFiles("main", f)
iprog, err := conf.Load()
if err != nil {
t.Error(err)
continue
}
prog := ssautil.CreateProgram(iprog, 0)
pkg := prog.Package(iprog.Created[0].Pkg)
pkg.Build()
name := "(none)"
fn := ssa.EnclosingFunction(pkg, path)
if fn != nil {
name = fn.String()
}
if name != test.fn {
t.Errorf("EnclosingFunction(%q in %q) got %s, want %s",
test.substr, test.input, name, test.fn)
continue
}
// While we're here: test HasEnclosingFunction.
if has := ssa.HasEnclosingFunction(pkg, path); has != (fn != nil) {
t.Errorf("HasEnclosingFunction(%q in %q) got %v, want %v",
test.substr, test.input, has, fn != nil)
continue
}
}
}