| Robert Griesemer | c910fd7 | 2021-02-02 13:20:03 -0800 | [diff] [blame] | 1 | // run |
| 2 | |
| 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. |
| 6 | |
| 7 | // Check that the compiler refuses excessively long constants. |
| 8 | |
| 9 | package main |
| 10 | |
| 11 | import ( |
| 12 | "bytes" |
| 13 | "fmt" |
| 14 | "io/ioutil" |
| 15 | "log" |
| 16 | "os" |
| 17 | "os/exec" |
| 18 | "path/filepath" |
| 19 | "runtime" |
| 20 | "strings" |
| 21 | ) |
| 22 | |
| 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. |
| Robert Griesemer | f80b126 | 2022-08-15 16:26:23 -0700 | [diff] [blame] | 27 | func testProg(dir, name string, length int, msg string) { |
| Robert Griesemer | c910fd7 | 2021-02-02 13:20:03 -0800 | [diff] [blame] | 28 | var buf bytes.Buffer |
| 29 | |
| 30 | fmt.Fprintf(&buf, |
| Robert Griesemer | f80b126 | 2022-08-15 16:26:23 -0700 | [diff] [blame] | 31 | "package %s; const _ = 0b%s // %d bits", |
| 32 | name, strings.Repeat("1", length), length, |
| Robert Griesemer | c910fd7 | 2021-02-02 13:20:03 -0800 | [diff] [blame] | 33 | ) |
| 34 | |
| 35 | filename := filepath.Join(dir, fmt.Sprintf("%s.go", name)) |
| 36 | if err := os.WriteFile(filename, buf.Bytes(), 0666); err != nil { |
| 37 | log.Fatal(err) |
| 38 | } |
| 39 | |
| Russ Cox | a987aaf | 2022-03-08 18:16:35 -0500 | [diff] [blame] | 40 | cmd := exec.Command("go", "tool", "compile", "-p=p", filename) |
| Robert Griesemer | c910fd7 | 2021-02-02 13:20:03 -0800 | [diff] [blame] | 41 | cmd.Dir = dir |
| 42 | output, err := cmd.CombinedOutput() |
| 43 | |
| Robert Griesemer | f80b126 | 2022-08-15 16:26:23 -0700 | [diff] [blame] | 44 | if msg == "" { |
| Robert Griesemer | c910fd7 | 2021-02-02 13:20:03 -0800 | [diff] [blame] | 45 | // no error expected |
| 46 | if err != nil { |
| 47 | log.Fatalf("%s: compile failed unexpectedly: %v", name, err) |
| 48 | } |
| 49 | return |
| 50 | } |
| 51 | |
| 52 | // error expected |
| 53 | if err == nil { |
| 54 | log.Fatalf("%s: compile succeeded unexpectedly", name) |
| 55 | } |
| Robert Griesemer | f80b126 | 2022-08-15 16:26:23 -0700 | [diff] [blame] | 56 | if !bytes.Contains(output, []byte(msg)) { |
| Robert Griesemer | c910fd7 | 2021-02-02 13:20:03 -0800 | [diff] [blame] | 57 | log.Fatalf("%s: wrong compiler error message:\n%s\n", name, output) |
| 58 | } |
| 59 | } |
| 60 | |
| 61 | func main() { |
| Johan Brandhorst-Satzkorn | 319b75e | 2023-03-25 17:01:38 -0700 | [diff] [blame] | 62 | if runtime.GOOS == "js" || runtime.GOOS == "wasip1" || runtime.Compiler != "gc" { |
| Robert Griesemer | c910fd7 | 2021-02-02 13:20:03 -0800 | [diff] [blame] | 63 | return |
| 64 | } |
| 65 | |
| 66 | dir, err := ioutil.TempDir("", "const7_") |
| 67 | if err != nil { |
| 68 | log.Fatalf("creating temp dir: %v\n", err) |
| 69 | } |
| 70 | defer os.RemoveAll(dir) |
| 71 | |
| Robert Griesemer | f80b126 | 2022-08-15 16:26:23 -0700 | [diff] [blame] | 72 | const bitLimit = 512 |
| 73 | const charLimit = 10000 // compiler-internal constant length limit |
| 74 | testProg(dir, "x1", bitLimit, "") |
| 75 | testProg(dir, "x2", bitLimit+1, "constant overflow") |
| 76 | testProg(dir, "x3", charLimit-2, "constant overflow") // -2 because literal contains 0b prefix |
| 77 | testProg(dir, "x4", charLimit-1, "excessively long constant") |
| Robert Griesemer | c910fd7 | 2021-02-02 13:20:03 -0800 | [diff] [blame] | 78 | } |