dlv: bugfix: Allow quoting in build flags argument (#639)

Allows quoted substrings in build-flags flag. This fixes a build
problem on windows where the default build flags must contain a space.

Fixes #634 and #638

_fixtures/buildtest/main.go

@@ -0,0 +1,7 @@
+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println("hello world!")
+}

cmd/dlv/cmds/commands.go

@@ -1,6 +1,7 @@
 package cmds
 
 import (
+	"bytes"
 	"errors"
 	"fmt"
 	"net"
@@ -10,8 +11,8 @@ import (
 	"path/filepath"
 	"runtime"
 	"strconv"
-	"strings"
 	"syscall"
+	"unicode"
 
 	"github.com/derekparker/delve/config"
 	"github.com/derekparker/delve/service"
@@ -68,7 +69,7 @@ func New() *cobra.Command {
 	buildFlagsDefault := ""
 	if runtime.GOOS == "windows" {
 		// Work-around for https://github.com/golang/go/issues/13154
-		buildFlagsDefault = "-ldflags=-linkmode internal"
+		buildFlagsDefault = "-ldflags='-linkmode internal'"
 	}
 
 	// Main dlv root command.
@@ -447,7 +448,7 @@ func execute(attachPid int, processArgs []string, conf *config.Config, kind exec
 func gobuild(debugname, pkg string) error {
 	args := []string{"-gcflags", "-N -l", "-o", debugname}
 	if BuildFlags != "" {
-		args = append(args, strings.Fields(BuildFlags)...)
+		args = append(args, splitQuotedFields(BuildFlags)...)
 	}
 	args = append(args, pkg)
 	return gocommand("build", args...)
@@ -456,7 +457,7 @@ func gobuild(debugname, pkg string) error {
 func gotestbuild(pkg string) error {
 	args := []string{"-gcflags", "-N -l", "-c", "-o", testdebugname}
 	if BuildFlags != "" {
-		args = append(args, strings.Fields(BuildFlags)...)
+		args = append(args, splitQuotedFields(BuildFlags)...)
 	}
 	args = append(args, pkg)
 	return gocommand("test", args...)
@@ -469,3 +470,60 @@ func gocommand(command string, args ...string) error {
 	goBuild.Stderr = os.Stderr
 	return goBuild.Run()
 }
+
+// Like strings.Fields but ignores spaces inside areas surrounded
+// by single quotes.
+// To specify a single quote use backslash to escape it: '\''
+func splitQuotedFields(in string) []string {
+	type stateEnum int
+	const (
+		inSpace stateEnum = iota
+		inField
+		inQuote
+		inQuoteEscaped
+	)
+	state := inSpace
+	r := []string{}
+	var buf bytes.Buffer
+
+	for _, ch := range in {
+		switch state {
+		case inSpace:
+			if ch == '\'' {
+				state = inQuote
+			} else if !unicode.IsSpace(ch) {
+				buf.WriteRune(ch)
+				state = inField
+			}
+
+		case inField:
+			if ch == '\'' {
+				state = inQuote
+			} else if unicode.IsSpace(ch) {
+				r = append(r, buf.String())
+				buf.Reset()
+			} else {
+				buf.WriteRune(ch)
+			}
+
+		case inQuote:
+			if ch == '\'' {
+				state = inField
+			} else if ch == '\\' {
+				state = inQuoteEscaped
+			} else {
+				buf.WriteRune(ch)
+			}
+
+		case inQuoteEscaped:
+			buf.WriteRune(ch)
+			state = inQuote
+		}
+	}
+
+	if buf.Len() != 0 {
+		r = append(r, buf.String())
+	}
+
+	return r
+}

cmd/dlv/cmds/commands_test.go

@@ -0,0 +1,21 @@
+package cmds
+
+import (
+	"testing"
+)
+
+func TestSplitQuotedFields(t *testing.T) {
+	in := `field'A' 'fieldB' fie'l\'d'C fieldD 'another field' fieldE`
+	tgt := []string{"fieldA", "fieldB", "fiel'dC", "fieldD", "another field", "fieldE"}
+	out := splitQuotedFields(in)
+
+	if len(tgt) != len(out) {
+		t.Fatalf("expected %#v, got %#v (len mismatch)", tgt, out)
+	}
+
+	for i := range tgt {
+		if tgt[i] != out[i] {
+			t.Fatalf(" expected %#v, got %#v (mismatch at %d)", tgt, out, i)
+		}
+	}
+}

cmd/dlv/dlv_test.go

@@ -0,0 +1,61 @@
+package main
+
+import (
+	"bufio"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"testing"
+
+	protest "github.com/derekparker/delve/proc/test"
+	"github.com/derekparker/delve/service/rpc2"
+)
+
+func assertNoError(err error, t testing.TB, s string) {
+	if err != nil {
+		_, file, line, _ := runtime.Caller(1)
+		fname := filepath.Base(file)
+		t.Fatalf("failed assertion at %s:%d: %s - %s\n", fname, line, s, err)
+	}
+}
+
+func TestBuild(t *testing.T) {
+	const listenAddr = "localhost:40573"
+	cmd := exec.Command("go", "build", "github.com/derekparker/delve/cmd/dlv")
+	assertNoError(cmd.Run(), t, "go build")
+	wd, _ := os.Getwd()
+	dlvbin := filepath.Join(wd, "dlv")
+
+	defer os.Remove(dlvbin)
+
+	fixtures := protest.FindFixturesDir()
+
+	buildtestdir := filepath.Join(fixtures, "buildtest")
+
+	cmd = exec.Command(dlvbin, "debug", "--headless=true", "--listen="+listenAddr, "--api-version=2")
+	cmd.Dir = buildtestdir
+	stdout, err := cmd.StdoutPipe()
+	assertNoError(err, t, "stdout pipe")
+	cmd.Start()
+	defer func() {
+		cmd.Process.Signal(os.Interrupt)
+		cmd.Wait()
+	}()
+
+	scan := bufio.NewScanner(stdout)
+	// wait for the debugger to start
+	scan.Scan()
+	go func() {
+		for scan.Scan() {
+			// keep pipe empty
+		}
+	}()
+
+	client := rpc2.NewClient(listenAddr)
+	state := <-client.Continue()
+
+	if !state.Exited {
+		t.Fatal("Program did not exit")
+	}
+}

terminal/command_test.go

@@ -13,8 +13,8 @@ import (
 	"github.com/derekparker/delve/proc/test"
 	"github.com/derekparker/delve/service"
 	"github.com/derekparker/delve/service/api"
-	"github.com/derekparker/delve/service/rpccommon"
 	"github.com/derekparker/delve/service/rpc2"
+	"github.com/derekparker/delve/service/rpccommon"
 )
 
 type FakeTerminal struct {