github.com/sanprasirt/go@v0.0.0-20170607001320-a027466e4b6d/src/cmd/compile/internal/gc/reproduciblebuilds_test.go (about)

     1  // Copyright 2017 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package gc_test
     6  
     7  import (
     8  	"bytes"
     9  	"internal/testenv"
    10  	"io/ioutil"
    11  	"os"
    12  	"os/exec"
    13  	"path/filepath"
    14  	"testing"
    15  )
    16  
    17  func TestReproducibleBuilds(t *testing.T) {
    18  	testenv.MustHaveGoBuild(t)
    19  	iters := 10
    20  	if testing.Short() {
    21  		iters = 4
    22  	}
    23  	t.Parallel()
    24  	var want []byte
    25  	tmp, err := ioutil.TempFile("", "")
    26  	if err != nil {
    27  		t.Fatalf("temp file creation failed: %v", err)
    28  	}
    29  	defer os.Remove(tmp.Name())
    30  	defer tmp.Close()
    31  	for i := 0; i < iters; i++ {
    32  		out, err := exec.Command(testenv.GoToolPath(t), "tool", "compile", "-o", tmp.Name(), filepath.Join("testdata", "reproducible", "issue20272.go")).CombinedOutput()
    33  		if err != nil {
    34  			t.Fatalf("failed to compile: %v\n%s", err, out)
    35  		}
    36  		obj, err := ioutil.ReadFile(tmp.Name())
    37  		if err != nil {
    38  			t.Fatalf("failed to read object file: %v", err)
    39  		}
    40  		if i == 0 {
    41  			want = obj
    42  		} else {
    43  			if !bytes.Equal(want, obj) {
    44  				t.Fatalf("builds produced different output after %d iters (%d bytes vs %d bytes)", i, len(want), len(obj))
    45  			}
    46  		}
    47  	}
    48  }