reproduciblebuilds_test.go

     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 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  	tests := []string{
    19  		"issue20272.go",
    20  		"issue27013.go",
    21  		"issue30202.go",
    22  	}
    23  
    24  	testenv.MustHaveGoBuild(t)
    25  	iters := 10
    26  	if testing.Short() {
    27  		iters = 4
    28  	}
    29  	t.Parallel()
    30  	for _, test := range tests {
    31  		test := test
    32  		t.Run(test, func(t *testing.T) {
    33  			t.Parallel()
    34  			var want []byte
    35  			tmp, err := ioutil.TempFile("", "")
    36  			if err != nil {
    37  				t.Fatalf("temp file creation failed: %v", err)
    38  			}
    39  			defer os.Remove(tmp.Name())
    40  			defer tmp.Close()
    41  			for i := 0; i < iters; i++ {
    42  				// Note: use -c 2 to expose any nondeterminism which is the result
    43  				// of the runtime scheduler.
    44  				out, err := exec.Command(testenv.GoToolPath(t), "tool", "compile", "-c", "2", "-o", tmp.Name(), filepath.Join("testdata", "reproducible", test)).CombinedOutput()
    45  				if err != nil {
    46  					t.Fatalf("failed to compile: %v\n%s", err, out)
    47  				}
    48  				obj, err := ioutil.ReadFile(tmp.Name())
    49  				if err != nil {
    50  					t.Fatalf("failed to read object file: %v", err)
    51  				}
    52  				if i == 0 {
    53  					want = obj
    54  				} else {
    55  					if !bytes.Equal(want, obj) {
    56  						t.Fatalf("builds produced different output after %d iters (%d bytes vs %d bytes)", i, len(want), len(obj))
    57  					}
    58  				}
    59  			}
    60  		})
    61  	}
    62  }
    63  
    64  func TestIssue38068(t *testing.T) {
    65  	testenv.MustHaveGoBuild(t)
    66  	t.Parallel()
    67  
    68  	// Compile a small package with and without the concurrent
    69  	// backend, then check to make sure that the resulting archives
    70  	// are identical.  Note: this uses "go tool compile" instead of
    71  	// "go build" since the latter will generate differnent build IDs
    72  	// if it sees different command line flags.
    73  	scenarios := []struct {
    74  		tag     string
    75  		args    string
    76  		libpath string
    77  	}{
    78  		{tag: "serial", args: "-c=1"},
    79  		{tag: "concurrent", args: "-c=2"}}
    80  
    81  	tmpdir, err := ioutil.TempDir("", "TestIssue38068")
    82  	if err != nil {
    83  		t.Fatal(err)
    84  	}
    85  	defer os.RemoveAll(tmpdir)
    86  
    87  	src := filepath.Join("testdata", "reproducible", "issue38068.go")
    88  	for i := range scenarios {
    89  		s := &scenarios[i]
    90  		s.libpath = filepath.Join(tmpdir, s.tag+".a")
    91  		// Note: use of "-p" required in order for DWARF to be generated.
    92  		cmd := exec.Command(testenv.GoToolPath(t), "tool", "compile", "-trimpath", "-p=issue38068", "-buildid=", s.args, "-o", s.libpath, src)
    93  		out, err := cmd.CombinedOutput()
    94  		if err != nil {
    95  			t.Fatalf("%v: %v:\n%s", cmd.Args, err, out)
    96  		}
    97  	}
    98  
    99  	readBytes := func(fn string) []byte {
   100  		payload, err := ioutil.ReadFile(fn)
   101  		if err != nil {
   102  			t.Fatalf("failed to read executable '%s': %v", fn, err)
   103  		}
   104  		return payload
   105  	}
   106  
   107  	b1 := readBytes(scenarios[0].libpath)
   108  	b2 := readBytes(scenarios[1].libpath)
   109  	if !bytes.Equal(b1, b2) {
   110  		t.Fatalf("concurrent and serial builds produced different output")
   111  	}
   112  }
   113
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