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  	"os"
    11  	"path/filepath"
    12  	"testing"
    13  )
    14  
    15  func TestReproducibleBuilds(t *testing.T) {
    16  	tests := []string{
    17  		"issue20272.go",
    18  		"issue27013.go",
    19  		"issue30202.go",
    20  	}
    21  
    22  	testenv.MustHaveGoBuild(t)
    23  	iters := 10
    24  	if testing.Short() {
    25  		iters = 4
    26  	}
    27  	t.Parallel()
    28  	for _, test := range tests {
    29  		test := test
    30  		t.Run(test, func(t *testing.T) {
    31  			t.Parallel()
    32  			var want []byte
    33  			tmp, err := os.CreateTemp("", "")
    34  			if err != nil {
    35  				t.Fatalf("temp file creation failed: %v", err)
    36  			}
    37  			defer os.Remove(tmp.Name())
    38  			defer tmp.Close()
    39  			for i := 0; i < iters; i++ {
    40  				// Note: use -c 2 to expose any nondeterminism which is the result
    41  				// of the runtime scheduler.
    42  				out, err := testenv.Command(t, testenv.GoToolPath(t), "tool", "compile", "-p=p", "-c", "2", "-o", tmp.Name(), filepath.Join("testdata", "reproducible", test)).CombinedOutput()
    43  				if err != nil {
    44  					t.Fatalf("failed to compile: %v\n%s", err, out)
    45  				}
    46  				obj, err := os.ReadFile(tmp.Name())
    47  				if err != nil {
    48  					t.Fatalf("failed to read object file: %v", err)
    49  				}
    50  				if i == 0 {
    51  					want = obj
    52  				} else {
    53  					if !bytes.Equal(want, obj) {
    54  						t.Fatalf("builds produced different output after %d iters (%d bytes vs %d bytes)", i, len(want), len(obj))
    55  					}
    56  				}
    57  			}
    58  		})
    59  	}
    60  }
    61  
    62  func TestIssue38068(t *testing.T) {
    63  	testenv.MustHaveGoBuild(t)
    64  	t.Parallel()
    65  
    66  	// Compile a small package with and without the concurrent
    67  	// backend, then check to make sure that the resulting archives
    68  	// are identical.  Note: this uses "go tool compile" instead of
    69  	// "go build" since the latter will generate different build IDs
    70  	// if it sees different command line flags.
    71  	scenarios := []struct {
    72  		tag     string
    73  		args    string
    74  		libpath string
    75  	}{
    76  		{tag: "serial", args: "-c=1"},
    77  		{tag: "concurrent", args: "-c=2"}}
    78  
    79  	tmpdir := t.TempDir()
    80  
    81  	src := filepath.Join("testdata", "reproducible", "issue38068.go")
    82  	for i := range scenarios {
    83  		s := &scenarios[i]
    84  		s.libpath = filepath.Join(tmpdir, s.tag+".a")
    85  		// Note: use of "-p" required in order for DWARF to be generated.
    86  		cmd := testenv.Command(t, testenv.GoToolPath(t), "tool", "compile", "-p=issue38068", "-buildid=", s.args, "-o", s.libpath, src)
    87  		out, err := cmd.CombinedOutput()
    88  		if err != nil {
    89  			t.Fatalf("%v: %v:\n%s", cmd.Args, err, out)
    90  		}
    91  	}
    92  
    93  	readBytes := func(fn string) []byte {
    94  		payload, err := os.ReadFile(fn)
    95  		if err != nil {
    96  			t.Fatalf("failed to read executable '%s': %v", fn, err)
    97  		}
    98  		return payload
    99  	}
   100  
   101  	b1 := readBytes(scenarios[0].libpath)
   102  	b2 := readBytes(scenarios[1].libpath)
   103  	if !bytes.Equal(b1, b2) {
   104  		t.Fatalf("concurrent and serial builds produced different output")
   105  	}
   106  }
   107
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