3 // Copyright 2021 The Go Authors. All rights reserved.
4 // Use of this source code is governed by a BSD-style
5 // license that can be found in the LICENSE file.
7 // Check that the compiler refuses excessively long constants.
23 // testProg creates a package called name, with path dir/name.go,
24 // which declares an untyped constant of the given length.
25 // testProg compiles this package and checks for the absence or
26 // presence of a constant literal error.
27 func testProg(dir, name string, G_option, length int, ok bool) {
31 "package %s; const _ = %s // %d digits",
32 name, strings.Repeat("9", length), length,
35 filename := filepath.Join(dir, fmt.Sprintf("%s.go", name))
36 if err := os.WriteFile(filename, buf.Bytes(), 0666); err != nil {
40 cmd := exec.Command("go", "tool", "compile", fmt.Sprintf("-G=%d", G_option), filename)
42 output, err := cmd.CombinedOutput()
47 log.Fatalf("%s: compile failed unexpectedly: %v", name, err)
54 log.Fatalf("%s: compile succeeded unexpectedly", name)
56 if !bytes.Contains(output, []byte("excessively long constant")) {
57 log.Fatalf("%s: wrong compiler error message:\n%s\n", name, output)
62 if runtime.GOOS == "js" || runtime.Compiler != "gc" {
66 dir, err := ioutil.TempDir("", "const7_")
68 log.Fatalf("creating temp dir: %v\n", err)
70 defer os.RemoveAll(dir)
72 const limit = 10000 // compiler-internal constant length limit
73 testProg(dir, "x1", 0, limit, true) // -G=0
74 testProg(dir, "x2", 0, limit+1, false) // -G=0
75 testProg(dir, "x1", 1, limit, true) // -G=1 (new type checker)
76 testProg(dir, "x2", 1, limit+1, false) // -G=1 (new type checker)