1 files changed, 230 insertions, 0 deletions
diff --git a/src/cmd/link/dwarf_test.go b/src/cmd/link/dwarf_test.go
new file mode 100644
index 0000000..53dc686
--- /dev/null
+++ b/src/cmd/link/dwarf_test.go
@@ -0,0 +1,230 @@
+// 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 main
+
+import (
+	"bytes"
+	cmddwarf "cmd/internal/dwarf"
+	"cmd/internal/objfile"
+	"cmd/internal/quoted"
+	"debug/dwarf"
+	"internal/testenv"
+	"os"
+	"os/exec"
+	"path"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
+)
+
+// TestMain allows this test binary to run as a -toolexec wrapper for the 'go'
+// command. If LINK_TEST_TOOLEXEC is set, TestMain runs the binary as if it were
+// cmd/link, and otherwise runs the requested tool as a subprocess.
+//
+// This allows the test to verify the behavior of the current contents of the
+// cmd/link package even if the installed cmd/link binary is stale.
+func TestMain(m *testing.M) {
+	if os.Getenv("LINK_TEST_TOOLEXEC") == "" {
+		// Not running as a -toolexec wrapper. Just run the tests.
+		os.Exit(m.Run())
+	}
+
+	if strings.TrimSuffix(filepath.Base(os.Args[1]), ".exe") == "link" {
+		// Running as a -toolexec linker, and the tool is cmd/link.
+		// Substitute this test binary for the linker.
+		os.Args = os.Args[1:]
+		main()
+		os.Exit(0)
+	}
+
+	cmd := exec.Command(os.Args[1], os.Args[2:]...)
+	cmd.Stdin = os.Stdin
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	if err := cmd.Run(); err != nil {
+		os.Exit(1)
+	}
+	os.Exit(0)
+}
+
+func testDWARF(t *testing.T, buildmode string, expectDWARF bool, env ...string) {
+	testenv.MustHaveCGO(t)
+	testenv.MustHaveGoBuild(t)
+
+	if runtime.GOOS == "plan9" {
+		t.Skip("skipping on plan9; no DWARF symbol table in executables")
+	}
+
+	t.Parallel()
+
+	for _, prog := range []string{"testprog", "testprogcgo"} {
+		prog := prog
+		expectDWARF := expectDWARF
+		if runtime.GOOS == "aix" && prog == "testprogcgo" {
+			extld := os.Getenv("CC")
+			if extld == "" {
+				extld = "gcc"
+			}
+			extldArgs, err := quoted.Split(extld)
+			if err != nil {
+				t.Fatal(err)
+			}
+			expectDWARF, err = cmddwarf.IsDWARFEnabledOnAIXLd(extldArgs)
+			if err != nil {
+				t.Fatal(err)
+			}
+		}
+
+		t.Run(prog, func(t *testing.T) {
+			t.Parallel()
+
+			tmpDir := t.TempDir()
+
+			exe := filepath.Join(tmpDir, prog+".exe")
+			dir := "../../runtime/testdata/" + prog
+			cmd := testenv.Command(t, testenv.GoToolPath(t), "build", "-toolexec", os.Args[0], "-o", exe)
+			if buildmode != "" {
+				cmd.Args = append(cmd.Args, "-buildmode", buildmode)
+			}
+			cmd.Args = append(cmd.Args, dir)
+			cmd.Env = append(os.Environ(), env...)
+			cmd.Env = append(cmd.Env, "CGO_CFLAGS=") // ensure CGO_CFLAGS does not contain any flags. Issue #35459
+			cmd.Env = append(cmd.Env, "LINK_TEST_TOOLEXEC=1")
+			out, err := cmd.CombinedOutput()
+			if err != nil {
+				t.Fatalf("go build -o %v %v: %v\n%s", exe, dir, err, out)
+			}
+
+			if buildmode == "c-archive" {
+				// Extract the archive and use the go.o object within.
+				cmd := testenv.Command(t, "ar", "-x", exe)
+				cmd.Dir = tmpDir
+				if out, err := cmd.CombinedOutput(); err != nil {
+					t.Fatalf("ar -x %s: %v\n%s", exe, err, out)
+				}
+				exe = filepath.Join(tmpDir, "go.o")
+			}
+
+			darwinSymbolTestIsTooFlaky := true // Turn this off, it is too flaky -- See #32218
+			if runtime.GOOS == "darwin" && !darwinSymbolTestIsTooFlaky {
+				if _, err = exec.LookPath("symbols"); err == nil {
+					// Ensure Apple's tooling can parse our object for symbols.
+					out, err = testenv.Command(t, "symbols", exe).CombinedOutput()
+					if err != nil {
+						t.Fatalf("symbols %v: %v: %s", filepath.Base(exe), err, out)
+					} else {
+						if bytes.HasPrefix(out, []byte("Unable to find file")) {
+							// This failure will cause the App Store to reject our binaries.
+							t.Fatalf("symbols %v: failed to parse file", filepath.Base(exe))
+						} else if bytes.Contains(out, []byte(", Empty]")) {
+							t.Fatalf("symbols %v: parsed as empty", filepath.Base(exe))
+						}
+					}
+				}
+			}
+
+			f, err := objfile.Open(exe)
+			if err != nil {
+				t.Fatal(err)
+			}
+			defer f.Close()
+
+			syms, err := f.Symbols()
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			var addr uint64
+			for _, sym := range syms {
+				if sym.Name == "main.main" {
+					addr = sym.Addr
+					break
+				}
+			}
+			if addr == 0 {
+				t.Fatal("cannot find main.main in symbols")
+			}
+
+			d, err := f.DWARF()
+			if err != nil {
+				if expectDWARF {
+					t.Fatal(err)
+				}
+				return
+			} else {
+				if !expectDWARF {
+					t.Fatal("unexpected DWARF section")
+				}
+			}
+
+			// TODO: We'd like to use filepath.Join here.
+			// Also related: golang.org/issue/19784.
+			wantFile := path.Join(prog, "main.go")
+			wantLine := 24
+			r := d.Reader()
+			entry, err := r.SeekPC(addr)
+			if err != nil {
+				t.Fatal(err)
+			}
+			lr, err := d.LineReader(entry)
+			if err != nil {
+				t.Fatal(err)
+			}
+			var line dwarf.LineEntry
+			if err := lr.SeekPC(addr, &line); err == dwarf.ErrUnknownPC {
+				t.Fatalf("did not find file:line for %#x (main.main)", addr)
+			} else if err != nil {
+				t.Fatal(err)
+			}
+			if !strings.HasSuffix(line.File.Name, wantFile) || line.Line != wantLine {
+				t.Errorf("%#x is %s:%d, want %s:%d", addr, line.File.Name, line.Line, filepath.Join("...", wantFile), wantLine)
+			}
+		})
+	}
+}
+
+func TestDWARF(t *testing.T) {
+	testDWARF(t, "", true)
+	if !testing.Short() {
+		if runtime.GOOS == "windows" {
+			t.Skip("skipping Windows/c-archive; see Issue 35512 for more.")
+		}
+		t.Run("c-archive", func(t *testing.T) {
+			testDWARF(t, "c-archive", true)
+		})
+	}
+}
+
+func TestDWARFiOS(t *testing.T) {
+	// Normally we run TestDWARF on native platform. But on iOS we don't have
+	// go build, so we do this test with a cross build.
+	// Only run this on darwin/amd64, where we can cross build for iOS.
+	if testing.Short() {
+		t.Skip("skipping in short mode")
+	}
+	if runtime.GOARCH != "amd64" || runtime.GOOS != "darwin" {
+		t.Skip("skipping on non-darwin/amd64 platform")
+	}
+	if err := testenv.Command(t, "xcrun", "--help").Run(); err != nil {
+		t.Skipf("error running xcrun, required for iOS cross build: %v", err)
+	}
+	// Check to see if the ios tools are installed. It's possible to have the command line tools
+	// installed without the iOS sdk.
+	if output, err := testenv.Command(t, "xcodebuild", "-showsdks").CombinedOutput(); err != nil {
+		t.Skipf("error running xcodebuild, required for iOS cross build: %v", err)
+	} else if !strings.Contains(string(output), "iOS SDK") {
+		t.Skipf("iOS SDK not detected.")
+	}
+	cc := "CC=" + runtime.GOROOT() + "/misc/ios/clangwrap.sh"
+	// iOS doesn't allow unmapped segments, so iOS executables don't have DWARF.
+	t.Run("exe", func(t *testing.T) {
+		testDWARF(t, "", false, cc, "CGO_ENABLED=1", "GOOS=ios", "GOARCH=arm64")
+	})
+	// However, c-archive iOS objects have embedded DWARF.
+	t.Run("c-archive", func(t *testing.T) {
+		testDWARF(t, "c-archive", true, cc, "CGO_ENABLED=1", "GOOS=ios", "GOARCH=arm64")
+	})
+}