Current File : //usr/local/go119/src/math/big/link_test.go
// Copyright 2020 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 big
import (
"bytes"
"internal/testenv"
"os"
"os/exec"
"path/filepath"
"testing"
)
// Tests that the linker is able to remove references to Float, Rat,
// and Int if unused (notably, not used by init).
func TestLinkerGC(t *testing.T) {
if testing.Short() {
t.Skip("skipping in short mode")
}
t.Parallel()
tmp := t.TempDir()
goBin := testenv.GoToolPath(t)
goFile := filepath.Join(tmp, "x.go")
file := []byte(`package main
import _ "math/big"
func main() {}
`)
if err := os.WriteFile(goFile, file, 0644); err != nil {
t.Fatal(err)
}
cmd := exec.Command(goBin, "build", "-o", "x.exe", "x.go")
cmd.Dir = tmp
if out, err := cmd.CombinedOutput(); err != nil {
t.Fatalf("compile: %v, %s", err, out)
}
cmd = exec.Command(goBin, "tool", "nm", "x.exe")
cmd.Dir = tmp
nm, err := cmd.CombinedOutput()
if err != nil {
t.Fatalf("nm: %v, %s", err, nm)
}
const want = "runtime.main"
if !bytes.Contains(nm, []byte(want)) {
// Test the test.
t.Errorf("expected symbol %q not found", want)
}
bad := []string{
"math/big.(*Float)",
"math/big.(*Rat)",
"math/big.(*Int)",
}
for _, sym := range bad {
if bytes.Contains(nm, []byte(sym)) {
t.Errorf("unexpected symbol %q found", sym)
}
}
if t.Failed() {
t.Logf("Got: %s", nm)
}
}
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