terminal,api: move PrintStack function (#2537)

Commit 30cdedae6910f5e9af6739845bacfd5b8778e745 introduced a dependency
from service/dap to pkg/terminal to call a stack printing function,
it's weird to have code that implements the DAP protocol depend on the
code for the JSON-RPC client.
Move PrintStack to a different package that can be called by both.

pkg/terminal/command.go

@@ -2331,71 +2331,8 @@ func digits(n int) int {
 	return int(math.Floor(math.Log10(float64(n)))) + 1
 }
 
-const stacktraceTruncatedMessage = "(truncated)"
-
 func printStack(t *Term, out io.Writer, stack []api.Stackframe, ind string, offsets bool) {
-	PrintStack(t.formatPath, out, stack, ind, offsets, func(api.Stackframe) bool { return true })
+	api.PrintStack(t.formatPath, out, stack, ind, offsets, func(api.Stackframe) bool { return true })
-}
-
-func PrintStack(formatPath func(string) string, out io.Writer, stack []api.Stackframe, ind string, offsets bool, include func(api.Stackframe) bool) {
-	if len(stack) == 0 {
-		return
-	}
-
-	extranl := offsets
-	for i := range stack {
-		if extranl {
-			break
-		}
-		extranl = extranl || (len(stack[i].Defers) > 0) || (len(stack[i].Arguments) > 0) || (len(stack[i].Locals) > 0)
-	}
-
-	d := digits(len(stack) - 1)
-	fmtstr := "%s%" + strconv.Itoa(d) + "d  0x%016x in %s\n"
-	s := ind + strings.Repeat(" ", d+2+len(ind))
-
-	for i := range stack {
-		if !include(stack[i]) {
-			continue
-		}
-		if stack[i].Err != "" {
-			fmt.Fprintf(out, "%serror: %s\n", s, stack[i].Err)
-			continue
-		}
-		fmt.Fprintf(out, fmtstr, ind, i, stack[i].PC, stack[i].Function.Name())
-		fmt.Fprintf(out, "%sat %s:%d\n", s, formatPath(stack[i].File), stack[i].Line)
-
-		if offsets {
-			fmt.Fprintf(out, "%sframe: %+#x frame pointer %+#x\n", s, stack[i].FrameOffset, stack[i].FramePointerOffset)
-		}
-
-		for j, d := range stack[i].Defers {
-			deferHeader := fmt.Sprintf("%s    defer %d: ", s, j+1)
-			s2 := strings.Repeat(" ", len(deferHeader))
-			if d.Unreadable != "" {
-				fmt.Fprintf(out, "%s(unreadable defer: %s)\n", deferHeader, d.Unreadable)
-				continue
-			}
-			fmt.Fprintf(out, "%s%#016x in %s\n", deferHeader, d.DeferredLoc.PC, d.DeferredLoc.Function.Name())
-			fmt.Fprintf(out, "%sat %s:%d\n", s2, formatPath(d.DeferredLoc.File), d.DeferredLoc.Line)
-			fmt.Fprintf(out, "%sdeferred by %s at %s:%d\n", s2, d.DeferLoc.Function.Name(), formatPath(d.DeferLoc.File), d.DeferLoc.Line)
-		}
-
-		for j := range stack[i].Arguments {
-			fmt.Fprintf(out, "%s    %s = %s\n", s, stack[i].Arguments[j].Name, stack[i].Arguments[j].SinglelineString())
-		}
-		for j := range stack[i].Locals {
-			fmt.Fprintf(out, "%s    %s = %s\n", s, stack[i].Locals[j].Name, stack[i].Locals[j].SinglelineString())
-		}
-
-		if extranl {
-			fmt.Fprintln(out)
-		}
-	}
-
-	if len(stack) > 0 && !stack[len(stack)-1].Bottom {
-		fmt.Fprintf(out, "%s"+stacktraceTruncatedMessage+"\n", ind)
-	}
 }
 
 func printcontext(t *Term, state *api.DebuggerState) {

pkg/terminal/command_test.go

@@ -943,6 +943,7 @@ func TestOptimizationCheck(t *testing.T) {
 }
 
 func TestTruncateStacktrace(t *testing.T) {
+	const stacktraceTruncatedMessage = "(truncated)"
 	withTestTerminal("stacktraceprog", t, func(term *FakeTerminal) {
 		term.MustExec("break main.stacktraceme")
 		term.MustExec("continue")

service/api/prettyprint.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"fmt"
 	"io"
+	"math"
 	"reflect"
 	"strconv"
 	"strings"
@@ -493,3 +494,73 @@ func byteArrayToUInt64(buf []byte, isLittleEndian bool) uint64 {
 	}
 	return n
 }
+
+const stacktraceTruncatedMessage = "(truncated)"
+
+func digits(n int) int {
+	if n <= 0 {
+		return 1
+	}
+	return int(math.Floor(math.Log10(float64(n)))) + 1
+}
+
+func PrintStack(formatPath func(string) string, out io.Writer, stack []Stackframe, ind string, offsets bool, include func(Stackframe) bool) {
+	if len(stack) == 0 {
+		return
+	}
+
+	extranl := offsets
+	for i := range stack {
+		if extranl {
+			break
+		}
+		extranl = extranl || (len(stack[i].Defers) > 0) || (len(stack[i].Arguments) > 0) || (len(stack[i].Locals) > 0)
+	}
+
+	d := digits(len(stack) - 1)
+	fmtstr := "%s%" + strconv.Itoa(d) + "d  0x%016x in %s\n"
+	s := ind + strings.Repeat(" ", d+2+len(ind))
+
+	for i := range stack {
+		if !include(stack[i]) {
+			continue
+		}
+		if stack[i].Err != "" {
+			fmt.Fprintf(out, "%serror: %s\n", s, stack[i].Err)
+			continue
+		}
+		fmt.Fprintf(out, fmtstr, ind, i, stack[i].PC, stack[i].Function.Name())
+		fmt.Fprintf(out, "%sat %s:%d\n", s, formatPath(stack[i].File), stack[i].Line)
+
+		if offsets {
+			fmt.Fprintf(out, "%sframe: %+#x frame pointer %+#x\n", s, stack[i].FrameOffset, stack[i].FramePointerOffset)
+		}
+
+		for j, d := range stack[i].Defers {
+			deferHeader := fmt.Sprintf("%s    defer %d: ", s, j+1)
+			s2 := strings.Repeat(" ", len(deferHeader))
+			if d.Unreadable != "" {
+				fmt.Fprintf(out, "%s(unreadable defer: %s)\n", deferHeader, d.Unreadable)
+				continue
+			}
+			fmt.Fprintf(out, "%s%#016x in %s\n", deferHeader, d.DeferredLoc.PC, d.DeferredLoc.Function.Name())
+			fmt.Fprintf(out, "%sat %s:%d\n", s2, formatPath(d.DeferredLoc.File), d.DeferredLoc.Line)
+			fmt.Fprintf(out, "%sdeferred by %s at %s:%d\n", s2, d.DeferLoc.Function.Name(), formatPath(d.DeferLoc.File), d.DeferLoc.Line)
+		}
+
+		for j := range stack[i].Arguments {
+			fmt.Fprintf(out, "%s    %s = %s\n", s, stack[i].Arguments[j].Name, stack[i].Arguments[j].SinglelineString())
+		}
+		for j := range stack[i].Locals {
+			fmt.Fprintf(out, "%s    %s = %s\n", s, stack[i].Locals[j].Name, stack[i].Locals[j].SinglelineString())
+		}
+
+		if extranl {
+			fmt.Fprintln(out)
+		}
+	}
+
+	if len(stack) > 0 && !stack[len(stack)-1].Bottom {
+		fmt.Fprintf(out, "%s"+stacktraceTruncatedMessage+"\n", ind)
+	}
+}

service/dap/server.go

@@ -32,7 +32,6 @@ import (
 	"github.com/go-delve/delve/pkg/locspec"
 	"github.com/go-delve/delve/pkg/logflags"
 	"github.com/go-delve/delve/pkg/proc"
-	"github.com/go-delve/delve/pkg/terminal"
 	"github.com/go-delve/delve/service"
 	"github.com/go-delve/delve/service/api"
 	"github.com/go-delve/delve/service/debugger"
@@ -2475,7 +2474,7 @@ func (s *Server) onExceptionInfoRequest(request *dap.ExceptionInfoRequest) {
 			fmt.Fprintln(&buf, "Stack:")
 			userLoc := g.UserCurrent()
 			userFuncPkg := fnPackageName(&userLoc)
-			terminal.PrintStack(s.toClientPath, &buf, apiFrames, "\t", false, func(s api.Stackframe) bool {
+			api.PrintStack(s.toClientPath, &buf, apiFrames, "\t", false, func(s api.Stackframe) bool {
 				// Include all stack frames if the stack trace is for a system goroutine,
 				// otherwise, skip runtime stack frames.
 				if userFuncPkg == "runtime" {