golang check_test 代码
文件路径：/src/go/types/check_test.go
/ Copyright 2011 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.
/ This file implements a typechecker test harness. The packages specified
/ in tests are typechecked. Error messages reported by the typechecker are
/ compared against the error messages expected in the test files.
/
/ Expected errors are indicated in the test files by putting a comment
/ of the form /* ERROR "rx" */ immediately following an offending token.
/ The harness will verify that an error matching the regular expression
/ rx is reported at that source position. Consecutive comments may be
/ used to indicate multiple errors for the same token position.
/
/ For instance, the following test file indicates that a "not declared"
/ error should be reported for the undeclared variable x:
/
/ package p
/ func f() {
/ _ = x /* ERROR "not declared" */ + 1
/ }
package types_test
import (
"bytes"
"flag"
"fmt"
"go/ast"
"go/importer"
"go/parser"
"go/scanner"
"go/token"
"internal/testenv"
"os"
"path/filepath"
"regexp"
"strings"
"testing"
. "go/types"
)
var (
haltOnError = flag.Bool("halt", false, "halt on error")
verifyErrors = flag.Bool("verify", false, "verify errors (rather than list them) in TestManual")
goVersion = flag.String("lang", "", "Go language version (e.g. \"go1.12\") for TestManual")
)
var fset = token.NewFileSet()
/ Positioned errors are of the form filename:line:column: message .
var posMsgRx = regexp.MustCompile(`^(.*:[0-9]+:[0-9]+): *(?s)(.*)`)
/ splitError splits an error's error message into a position string
/ and the actual error message. If there's no position information,
/ pos is the empty string, and msg is the entire error message.
func splitError(err error) (pos, msg string) {
msg = err.Error()
if m := posMsgRx.FindStringSubmatch(msg); len(m) == 3 {
pos = m[1]
msg = m[2]
}
return
}
func parseFiles(t *testing.T, filenames []string, srcs [][]byte, mode parser.Mode) ([]*ast.File, []error) {
var files []*ast.File
var errlist []error
for i, filename := range filenames {
file, err := parser.ParseFile(fset, filename, srcs[i], mode)
if file == nil {
t.Fatalf("%s: %s", filename, err)
}
files = append(files, file)
if err != nil {
if list, _ := err.(scanner.ErrorList); len(list) > 0 {
for _, err := range list {
errlist = append(errlist, err)
}
} else {
errlist = append(errlist, err)
}
}
}
return files, errlist
}
/ ERROR comments must start with text `ERROR "rx"` or `ERROR rx` where
/ rx is a regular expression that matches the expected error message.
/ Space around "rx" or rx is ignored. Use the form `ERROR HERE "rx"`
/ for error messages that are located immediately after rather than
/ at a token's position.
var errRx = regexp.MustCompile(`^ *ERROR *(HERE)? *"?([^"]*)"?`)
/ errMap collects the regular expressions of ERROR comments found
/ in files and returns them as a map of error positions to error messages.
/
/ srcs must be a slice of the same length as files, containing the original
/ source for the parsed AST.
func errMap(t *testing.T, files []*ast.File, srcs [][]byte) map[string][]string {
/ map of position strings to lists of error message patterns
errmap := make(map[string][]string)
for i, file := range files {
tok := fset.File(file.Package)
src := srcs[i]
var s scanner.Scanner
s.Init(tok, src, nil, scanner.ScanComments)
var prev token.Pos / position of last non-comment, non-semicolon token
var here token.Pos / position immediately after the token at position prev
scanFile:
for {
pos, tok, lit := s.Scan()
switch tok {
case token.EOF:
break scanFile
case token.COMMENT:
if lit[1] == '*' {
lit = lit[:len(lit)-2] / strip trailing */
}
if s := errRx.FindStringSubmatch(lit[2:]); len(s) == 3 {
pos := prev
if s[1] == "HERE" {
pos = here
}
p := fset.Position(pos).String()
errmap[p] = append(errmap[p], strings.TrimSpace(s[2]))
}
case token.SEMICOLON:
/ ignore automatically inserted semicolon
if lit == "\n" {
continue scanFile
}
fallthrough
default:
prev = pos
var l int / token length
if tok.IsLiteral() {
l = len(lit)
} else {
l = len(tok.String())
}
here = prev + token.Pos(l)
}
}
}
return errmap
}
func eliminate(t *testing.T, errmap map[string][]string, errlist []error) {
for _, err := range errlist {
pos, gotMsg := splitError(err)
list := errmap[pos]
index := -1 / list index of matching message, if any
/ we expect one of the messages in list to match the error at pos
for i, wantRx := range list {
rx, err := regexp.Compile(wantRx)
if err != nil {
t.Errorf("%s: %v", pos, err)
continue
}
if rx.MatchString(gotMsg) {
index = i
break
}
}
if index >= 0 {
/ eliminate from list
if n := len(list) - 1; n > 0 {
/ not the last entry - swap in last element and shorten list by 1
list[index] = list[n]
errmap[pos] = list[:n]
} else {
/ last entry - remove list from map
delete(errmap, pos)
}
} else {
t.Errorf("%s: no error expected: %q", pos, gotMsg)
}
}
}
/ parseFlags parses flags from the first line of the given source
/ (from src if present, or by reading from the file) if the line
/ starts with "/" (line comment) followed by "-" (possiby with
/ spaces between). Otherwise the line is ignored.
func parseFlags(filename string, src []byte, flags *flag.FlagSet) error {
/ If there is no src, read from the file.
const maxLen = 256
if len(src) == 0 {
f, err := os.Open(filename)
if err != nil {
return err
}
var buf [maxLen]byte
n, err := f.Read(buf[:])
if err != nil {
return err
}
src = buf[:n]
}
/ we must have a line comment that starts with a "-"
const prefix = "/"
if !bytes.HasPrefix(src, []byte(prefix)) {
return nil / first line is not a line comment
}
src = src[len(prefix):]
if i := bytes.Index(src, []byte("-")); i < 0 || len(bytes.TrimSpace(src[:i])) != 0 {
return nil / comment doesn't start with a "-"
}
end := bytes.Index(src, []byte("\n"))
if end < 0 || end > maxLen {
return fmt.Errorf("flags comment line too long")
}
return flags.Parse(strings.Fields(string(src[:end])))
}
func testFiles(t *testing.T, sizes Sizes, filenames []string, srcs [][]byte, manual bool, imp Importer) {
if len(filenames) == 0 {
t.Fatal("no source files")
}
var conf Config
conf.Sizes = sizes
flags := flag.NewFlagSet("", flag.PanicOnError)
flags.StringVar(&conf.GoVersion, "lang", "", "")
flags.BoolVar(&conf.FakeImportC, "fakeImportC", false, "")
if err := parseFlags(filenames[0], srcs[0], flags); err != nil {
t.Fatal(err)
}
if manual && *goVersion != "" {
/ goVersion overrides -lang for manual tests.
conf.GoVersion = *goVersion
}
/ TODO(gri) remove this or use flag mechanism to set mode if still needed
if strings.HasSuffix(filenames[0], ".go1") {
/ TODO(rfindley): re-enable this test by using GoVersion.
t.Skip("type params are enabled")
}
files, errlist := parseFiles(t, filenames, srcs, parser.AllErrors)
pkgName := "<no package>"
if len(files) > 0 {
pkgName = files[0].Name.Name
}
listErrors := manual && !*verifyErrors
if listErrors && len(errlist) > 0 {
t.Errorf("--- %s:", pkgName)
for _, err := range errlist {
t.Error(err)
}
}
/ typecheck and collect typechecker errors
if imp == nil {
imp = importer.Default()
}
conf.Importer = imp
conf.Error = func(err error) {
if *haltOnError {
defer panic(err)
}
if listErrors {
t.Error(err)
return
}
/ Ignore secondary error messages starting with "\t";
/ they are clarifying messages for a primary error.
if !strings.Contains(err.Error(), ": \t") {
errlist = append(errlist, err)
}
}
conf.Check(pkgName, fset, files, nil)
if listErrors {
return
}
for _, err := range errlist {
err, ok := err.(Error)
if !ok {
continue
}
code := readCode(err)
if code == 0 {
t.Errorf("missing error code: %v", err)
}
}
/ match and eliminate errors;
/ we are expecting the following errors
errmap := errMap(t, files, srcs)
eliminate(t, errmap, errlist)
/ there should be no expected errors left
if len(errmap) > 0 {
t.Errorf("--- %s: %d source positions with expected (but not reported) errors:", pkgName, len(errmap))
for pos, list := range errmap {
for _, rx := range list {
t.Errorf("%s: %q", pos, rx)
}
}
}
}
/ TestManual is for manual testing of a package - either provided
/ as a list of filenames belonging to the package, or a directory
/ name containing the package files - after the test arguments
/ (and a separating "--"). For instance, to test the package made
/ of the files foo.go and bar.go, use:
/
/ go test -run Manual -- foo.go bar.go
/
/ If no source arguments are provided, the file testdata/manual.go
/ is used instead.
/ Provide the -verify flag to verify errors against ERROR comments
/ in the input files rather than having a list of errors reported.
/ The accepted Go language version can be controlled with the -lang
/ flag.
func TestManual(t *testing.T) {
testenv.MustHaveGoBuild(t)
filenames := flag.Args()
if len(filenames) == 0 {
filenames = []string{filepath.FromSlash("testdata/manual.go")}
}
info, err := os.Stat(filenames[0])
if err != nil {
t.Fatalf("TestManual: %v", err)
}
DefPredeclaredTestFuncs()
if info.IsDir() {
if len(filenames) > 1 {
t.Fatal("TestManual: must have only one directory argument")
}
testDir(t, filenames[0], true)
} else {
testPkg(t, filenames, true)
}
}
func TestLongConstants(t *testing.T) {
format := "package longconst\n\nconst _ = %s\nconst _ = %s / ERROR excessively long constant"
src := fmt.Sprintf(format, strings.Repeat("1", 9999), strings.Repeat("1", 10001))
testFiles(t, nil, []string{"longconst.go"}, [][]byte{[]byte(src)}, false, nil)
}
/ TestIndexRepresentability tests that constant index operands must
/ be representable as int even if they already have a type that can
/ represent larger values.
func TestIndexRepresentability(t *testing.T) {
const src = "package index\n\nvar s []byte\nvar _ = s[int64 /* ERROR \"int64\\(1\\) << 40 \\(.*\\) overflows int\" */ (1) << 40]"
testFiles(t, &StdSizes{4, 4}, []string{"index.go"}, [][]byte{[]byte(src)}, false, nil)
}
func TestIssue47243_TypedRHS(t *testing.T) {
/ The RHS of the shift expression below overflows uint on 32bit platforms,
/ but this is OK as it is explicitly typed.
const src = "package issue47243\n\nvar a uint64; var _ = a << uint64(4294967296)" / uint64(1<<32)
testFiles(t, &StdSizes{4, 4}, []string{"p.go"}, [][]byte{[]byte(src)}, false, nil)
}
func TestCheck(t *testing.T) { DefPredeclaredTestFuncs(); testDirFiles(t, "testdata/check", false) }
func TestSpec(t *testing.T) { testDirFiles(t, "testdata/spec", false) }
func TestExamples(t *testing.T) { testDirFiles(t, "testdata/examples", false) }
func TestFixedbugs(t *testing.T) { testDirFiles(t, "testdata/fixedbugs", false) }
func testDirFiles(t *testing.T, dir string, manual bool) {
testenv.MustHaveGoBuild(t)
dir = filepath.FromSlash(dir)
fis, err := os.ReadDir(dir)
if err != nil {
t.Error(err)
return
}
for _, fi := range fis {
path := filepath.Join(dir, fi.Name())
/ If fi is a directory, its files make up a single package.
if fi.IsDir() {
testDir(t, path, manual)
} else {
t.Run(filepath.Base(path), func(t *testing.T) {
testPkg(t, []string{path}, manual)
})
}
}
}
func testDir(t *testing.T, dir string, manual bool) {
testenv.MustHaveGoBuild(t)
fis, err := os.ReadDir(dir)
if err != nil {
t.Error(err)
return
}
var filenames []string
for _, fi := range fis {
filenames = append(filenames, filepath.Join(dir, fi.Name()))
}
t.Run(filepath.Base(dir), func(t *testing.T) {
testPkg(t, filenames, manual)
})
}
/ TODO(rFindley) reconcile the different test setup in go/types with types2.
func testPkg(t *testing.T, filenames []string, manual bool) {
srcs := make([][]byte, len(filenames))
for i, filename := range filenames {
src, err := os.ReadFile(filename)
if err != nil {
t.Fatalf("could not read %s: %v", filename, err)
}
srcs[i] = src
}
testFiles(t, nil, filenames, srcs, manual, nil)
}