1 files changed, 112 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/gc/reproduciblebuilds_test.go b/src/cmd/compile/internal/gc/reproduciblebuilds_test.go
new file mode 100644
index 0000000..8101e44
--- /dev/null
+++ b/src/cmd/compile/internal/gc/reproduciblebuilds_test.go
@@ -0,0 +1,112 @@
+// Copyright 2017 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 gc_test
+
+import (
+	"bytes"
+	"internal/testenv"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"testing"
+)
+
+func TestReproducibleBuilds(t *testing.T) {
+	tests := []string{
+		"issue20272.go",
+		"issue27013.go",
+		"issue30202.go",
+	}
+
+	testenv.MustHaveGoBuild(t)
+	iters := 10
+	if testing.Short() {
+		iters = 4
+	}
+	t.Parallel()
+	for _, test := range tests {
+		test := test
+		t.Run(test, func(t *testing.T) {
+			t.Parallel()
+			var want []byte
+			tmp, err := ioutil.TempFile("", "")
+			if err != nil {
+				t.Fatalf("temp file creation failed: %v", err)
+			}
+			defer os.Remove(tmp.Name())
+			defer tmp.Close()
+			for i := 0; i < iters; i++ {
+				// Note: use -c 2 to expose any nondeterminism which is the result
+				// of the runtime scheduler.
+				out, err := exec.Command(testenv.GoToolPath(t), "tool", "compile", "-c", "2", "-o", tmp.Name(), filepath.Join("testdata", "reproducible", test)).CombinedOutput()
+				if err != nil {
+					t.Fatalf("failed to compile: %v\n%s", err, out)
+				}
+				obj, err := ioutil.ReadFile(tmp.Name())
+				if err != nil {
+					t.Fatalf("failed to read object file: %v", err)
+				}
+				if i == 0 {
+					want = obj
+				} else {
+					if !bytes.Equal(want, obj) {
+						t.Fatalf("builds produced different output after %d iters (%d bytes vs %d bytes)", i, len(want), len(obj))
+					}
+				}
+			}
+		})
+	}
+}
+
+func TestIssue38068(t *testing.T) {
+	testenv.MustHaveGoBuild(t)
+	t.Parallel()
+
+	// Compile a small package with and without the concurrent
+	// backend, then check to make sure that the resulting archives
+	// are identical.  Note: this uses "go tool compile" instead of
+	// "go build" since the latter will generate differnent build IDs
+	// if it sees different command line flags.
+	scenarios := []struct {
+		tag     string
+		args    string
+		libpath string
+	}{
+		{tag: "serial", args: "-c=1"},
+		{tag: "concurrent", args: "-c=2"}}
+
+	tmpdir, err := ioutil.TempDir("", "TestIssue38068")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tmpdir)
+
+	src := filepath.Join("testdata", "reproducible", "issue38068.go")
+	for i := range scenarios {
+		s := &scenarios[i]
+		s.libpath = filepath.Join(tmpdir, s.tag+".a")
+		// Note: use of "-p" required in order for DWARF to be generated.
+		cmd := exec.Command(testenv.GoToolPath(t), "tool", "compile", "-trimpath", "-p=issue38068", "-buildid=", s.args, "-o", s.libpath, src)
+		out, err := cmd.CombinedOutput()
+		if err != nil {
+			t.Fatalf("%v: %v:\n%s", cmd.Args, err, out)
+		}
+	}
+
+	readBytes := func(fn string) []byte {
+		payload, err := ioutil.ReadFile(fn)
+		if err != nil {
+			t.Fatalf("failed to read executable '%s': %v", fn, err)
+		}
+		return payload
+	}
+
+	b1 := readBytes(scenarios[0].libpath)
+	b2 := readBytes(scenarios[1].libpath)
+	if !bytes.Equal(b1, b2) {
+		t.Fatalf("concurrent and serial builds produced different output")
+	}
+}