Add pprofLabelForThreadNames config

The config is a string value that indicates the key of a pprof label whose value
should be shown as a goroutine name in the threads view.

Documentation/api/dap/README.md

@@ -33,6 +33,7 @@ In addition to the general [DAP spec](https://microsoft.github.io/debug-adapter-
     stackTraceDepth<br>
     showGlobalVariables<br>
     showRegisters<br>
+    showPprofLabels<br>
     hideSystemGoroutines<br>
     goroutineFilters
     </tr>

service/dap/command.go

@@ -62,7 +62,14 @@ Type "help" followed by the name of a command for more information about it.`
 	dlv config substitutePath -clear
 	
 		Adds or removes a path substitution rule. If -clear is used all substitutePath rules are removed.
-		See also Documentation/cli/substitutepath.md.`
+		See also Documentation/cli/substitutepath.md.
+
+	dlv config showPprofLabels <label>
+	dlv config showPprofLabels -clear <label>
+	dlv config showPprofLabels -clear
+
+		Adds or removes a label key to show in the callstack view. If -clear is used without an argument,
+		all labels are removed.`
 	msgSources = `Print list of source files.
 
 	dlv sources [<regex>]
@@ -138,7 +145,7 @@ func (s *Session) evaluateConfig(_, _ int, expr string) (string, error) {
 					Areas: []dap.InvalidatedAreas{"variables"},
 				},
 			})
-		case "goroutineFilters", "hideSystemGoroutines":
+		case "goroutineFilters", "hideSystemGoroutines", "showPprofLabels":
 			// Thread related data has become invalidated.
 			s.send(&dap.InvalidatedEvent{
 				Event: *newEvent("invalidated"),

service/dap/config.go

@@ -37,6 +37,15 @@ func configureSet(sargs *launchAttachArgs, args string) (bool, string, error) {
 		return true, config.ConfigureListByName(sargs, cfgname, "cfgName"), nil
 	}
 
+	if cfgname == "showPprofLabels" {
+		err := configureSetShowPprofLabels(sargs, rest)
+		if err != nil {
+			return false, "", err
+		}
+		// Print the updated labels
+		return true, config.ConfigureListByName(sargs, cfgname, "cfgName"), nil
+	}
+
 	err := config.ConfigureSetSimple(rest, cfgname, field)
 	if err != nil {
 		return false, "", err
@@ -85,3 +94,37 @@ func configureSetSubstitutePath(args *launchAttachArgs, rest string) error {
 	}
 	return nil
 }
+
+func configureSetShowPprofLabels(args *launchAttachArgs, rest string) error {
+	if strings.TrimSpace(rest) == "-clear" {
+		args.ShowPprofLabels = args.ShowPprofLabels[:0]
+		return nil
+	}
+	delete := false
+	argv := config.SplitQuotedFields(rest, '"')
+	if len(argv) == 2 && argv[0] == "-clear" {
+		argv = argv[1:]
+		delete = true
+	}
+	switch len(argv) {
+	case 0:
+		// do nothing, let caller show the current list of labels
+		return nil
+	case 1:
+		if delete {
+			for i := range args.ShowPprofLabels {
+				if args.ShowPprofLabels[i] == argv[0] {
+					copy(args.ShowPprofLabels[i:], args.ShowPprofLabels[i+1:])
+					args.ShowPprofLabels = args.ShowPprofLabels[:len(args.ShowPprofLabels)-1]
+					return nil
+				}
+			}
+			return fmt.Errorf("could not find label %q", argv[0])
+		} else {
+			args.ShowPprofLabels = append(args.ShowPprofLabels, argv[0])
+		}
+	default:
+		return fmt.Errorf("too many arguments to \"config showPprofLabels\"")
+	}
+	return nil
+}

service/dap/config_test.go

@@ -18,26 +18,28 @@ func TestListConfig(t *testing.T) {
 			args: args{
 				args: &launchAttachArgs{},
 			},
-			want: formatConfig(0, false, false, "", false, [][2]string{}),
+			want: formatConfig(0, false, false, "", []string{}, false, [][2]string{}),
 		},
 		{
 			name: "default values",
 			args: args{
 				args: &defaultArgs,
 			},
-			want: formatConfig(50, false, false, "", false, [][2]string{}),
+			want: formatConfig(50, false, false, "", []string{}, false, [][2]string{}),
 		},
 		{
 			name: "custom values",
 			args: args{
 				args: &launchAttachArgs{
 					StackTraceDepth:              35,
 					ShowGlobalVariables:          true,
+					GoroutineFilters:             "SomeFilter",
+					ShowPprofLabels:              []string{"SomeLabel"},
 					substitutePathClientToServer: [][2]string{{"hello", "world"}},
 					substitutePathServerToClient: [][2]string{{"world", "hello"}},
 				},
 			},
-			want: formatConfig(35, true, false, "", false, [][2]string{{"hello", "world"}}),
+			want: formatConfig(35, true, false, "SomeFilter", []string{"SomeLabel"}, false, [][2]string{{"hello", "world"}}),
 		},
 	}
 	for _, tt := range tests {

service/dap/server.go

@@ -222,6 +222,11 @@ type launchAttachArgs struct {
 	ShowRegisters bool `cfgName:"showRegisters"`
 	// GoroutineFilters are the filters used when loading goroutines.
 	GoroutineFilters string `cfgName:"goroutineFilters"`
+	// ShowPprofLabels is an array of keys of pprof labels to show as a
+	// goroutine name in the threads view. If the array has one element, only
+	// that label's value will be shown; otherwise, each of the labels will be
+	// shown as "key:value". To show all labels, specify the single element "*".
+	ShowPprofLabels []string `cfgName:"showPprofLabels"`
 	// HideSystemGoroutines indicates if system goroutines should be removed from threads
 	// responses.
 	HideSystemGoroutines bool `cfgName:"hideSystemGoroutines"`
@@ -241,6 +246,7 @@ var defaultArgs = launchAttachArgs{
 	HideSystemGoroutines:         false,
 	ShowRegisters:                false,
 	GoroutineFilters:             "",
+	ShowPprofLabels:              []string{},
 	substitutePathClientToServer: [][2]string{},
 	substitutePathServerToClient: [][2]string{},
 }
@@ -353,6 +359,7 @@ func (s *Session) setLaunchAttachArgs(args LaunchAttachCommonConfig) {
 	s.args.ShowRegisters = args.ShowRegisters
 	s.args.HideSystemGoroutines = args.HideSystemGoroutines
 	s.args.GoroutineFilters = args.GoroutineFilters
+	s.args.ShowPprofLabels = args.ShowPprofLabels
 	if paths := args.SubstitutePath; len(paths) > 0 {
 		clientToServer := make([][2]string, 0, len(paths))
 		serverToClient := make([][2]string, 0, len(paths))
@@ -1815,10 +1822,41 @@ func (s *Session) onThreadsRequest(request *dap.ThreadsRequest) {
 			if g.Thread != nil && g.Thread.ThreadID() != 0 {
 				thread = fmt.Sprintf(" (Thread %d)", g.Thread.ThreadID())
 			}
+			var labels strings.Builder
+			writeLabelsForKeys := func(keys []string) {
+				for _, k := range keys {
+					labelValue := g.Labels()[k]
+					if labelValue != "" {
+						labels.WriteByte(' ')
+						labels.WriteString(k)
+						labels.WriteByte(':')
+						labels.WriteString(labelValue)
+					}
+				}
+			}
+			if len(s.args.ShowPprofLabels) == 1 {
+				labelKey := s.args.ShowPprofLabels[0]
+				if labelKey == "*" {
+					keys := make([]string, 0, len(g.Labels()))
+					for k := range g.Labels() {
+						keys = append(keys, k)
+					}
+					sort.Strings(keys)
+					writeLabelsForKeys(keys)
+				} else {
+					labelValue := g.Labels()[labelKey]
+					if labelValue != "" {
+						labels.WriteByte(' ')
+						labels.WriteString(labelValue)
+					}
+				}
+			} else {
+				writeLabelsForKeys(s.args.ShowPprofLabels)
+			}
 			// File name and line number are communicated via `stackTrace`
 			// so no need to include them here.
 			loc := g.UserCurrent()
-			threads[i].Name = fmt.Sprintf("%s[Go %d] %s%s", selected, g.ID, fnName(&loc), thread)
+			threads[i].Name = fmt.Sprintf("%s[Go %d%s] %s%s", selected, g.ID, labels.String(), fnName(&loc), thread)
 			threads[i].Id = int(g.ID)
 		}
 	}

service/dap/server_test.go

@@ -1396,6 +1396,68 @@ func TestSelectedThreadsRequest(t *testing.T) {
 	})
 }
 
+func TestGoroutineLabels(t *testing.T) {
+	tests := []struct {
+		showPprofLabelsConfig   []string
+		expectedPrefixWithLabel string
+	}{
+		{[]string{}, "* [Go 1]"},
+		{[]string{"k1"}, "* [Go 1 v1]"},
+		{[]string{"k2"}, "* [Go 1 v2]"},
+		{[]string{"k2", "k1"}, "* [Go 1 k2:v2 k1:v1]"}, // When passing keys explicitly, we show them in the given order
+		{[]string{"unknown"}, "* [Go 1]"},
+		{[]string{"unknown", "k1"}, "* [Go 1 k1:v1]"},
+		{[]string{"*"}, "* [Go 1 k1:v1 k2:v2]"}, // Special case for showing all labels; labels are shown sorted by key
+	}
+	for _, tc := range tests {
+		runTest(t, "goroutineLabels", func(client *daptest.Client, fixture protest.Fixture) {
+			runDebugSessionWithBPs(t, client, "launch",
+				// Launch
+				func() {
+					client.LaunchRequestWithArgs(map[string]interface{}{
+						"mode":                 "exec",
+						"program":              fixture.Path,
+						"hideSystemGoroutines": true,
+						"showPprofLabels":      tc.showPprofLabelsConfig,
+						"stopOnEntry":          !stopOnEntry,
+					})
+				},
+				// Breakpoints are set within the program
+				"", []int{},
+				[]onBreakpoint{{
+					execute: func() {
+						client.ThreadsRequest()
+						tr := client.ExpectThreadsResponse(t)
+						if len(tr.Body.Threads) != 1 {
+							t.Errorf("got %d threads, expected 1\n", len(tr.Body.Threads))
+						}
+						// The first breakpoint is before the call to pprof.Do; no labels yet:
+						expectedPrefix := "* [Go 1]"
+						if !strings.HasPrefix(tr.Body.Threads[0].Name, expectedPrefix) {
+							t.Errorf("got %s, expected %s\n", tr.Body.Threads[0].Name, expectedPrefix)
+						}
+
+						client.ContinueRequest(1)
+						client.ExpectContinueResponse(t)
+						client.ExpectStoppedEvent(t)
+						checkStop(t, client, 1, "main.f", 21)
+						client.ThreadsRequest()
+						tr = client.ExpectThreadsResponse(t)
+						if len(tr.Body.Threads) != 1 {
+							t.Errorf("got %d threads, expected 1\n", len(tr.Body.Threads))
+						}
+						// The second breakpoint is inside pprof.Do, so there are labels:
+						if !strings.HasPrefix(tr.Body.Threads[0].Name, tc.expectedPrefixWithLabel) {
+							t.Errorf("got %s, expected %s\n", tr.Body.Threads[0].Name, tc.expectedPrefixWithLabel)
+						}
+					},
+					disconnect: true,
+				}},
+			)
+		})
+	}
+}
+
 func TestHideSystemGoroutinesRequest(t *testing.T) {
 	tests := []struct{ hideSystemGoroutines bool }{
 		{hideSystemGoroutines: true},
@@ -4054,15 +4116,16 @@ func TestEvaluateRequest(t *testing.T) {
 	})
 }
 
-func formatConfig(depth int, showGlobals, showRegisters bool, goroutineFilters string, hideSystemGoroutines bool, substitutePath [][2]string) string {
+func formatConfig(depth int, showGlobals, showRegisters bool, goroutineFilters string, showPprofLabels []string, hideSystemGoroutines bool, substitutePath [][2]string) string {
 	formatStr := `stackTraceDepth	%d
 showGlobalVariables	%v
 showRegisters	%v
 goroutineFilters	%q
+showPprofLabels	%v
 hideSystemGoroutines	%v
 substitutePath	%v
 `
-	return fmt.Sprintf(formatStr, depth, showGlobals, showRegisters, goroutineFilters, hideSystemGoroutines, substitutePath)
+	return fmt.Sprintf(formatStr, depth, showGlobals, showRegisters, goroutineFilters, showPprofLabels, hideSystemGoroutines, substitutePath)
 }
 
 func TestEvaluateCommandRequest(t *testing.T) {
@@ -4099,7 +4162,7 @@ Type 'dlv help' followed by a command for full documentation.
 
 					client.EvaluateRequest("dlv config -list", 1000, "repl")
 					got = client.ExpectEvaluateResponse(t)
-					checkEval(t, got, formatConfig(50, false, false, "", false, [][2]string{}), noChildren)
+					checkEval(t, got, formatConfig(50, false, false, "", []string{}, false, [][2]string{}), noChildren)
 
 					// Read and modify showGlobalVariables.
 					client.EvaluateRequest("dlv config -list showGlobalVariables", 1000, "repl")
@@ -4120,7 +4183,7 @@ Type 'dlv help' followed by a command for full documentation.
 
 					client.EvaluateRequest("dlv config -list", 1000, "repl")
 					got = client.ExpectEvaluateResponse(t)
-					checkEval(t, got, formatConfig(50, true, false, "", false, [][2]string{}), noChildren)
+					checkEval(t, got, formatConfig(50, true, false, "", []string{}, false, [][2]string{}), noChildren)
 
 					client.ScopesRequest(1000)
 					scopes = client.ExpectScopesResponse(t)

service/dap/types.go

@@ -190,6 +190,12 @@ type LaunchAttachCommonConfig struct {
 	// https://github.com/go-delve/delve/blob/master/Documentation/cli/README.md#goroutines
 	GoroutineFilters string `json:"goroutineFilters,omitempty"`
 
+	// Array of string values indicating the keys of pprof labels to show as a
+	// goroutine name in the threads view. If the array has one element, only
+	// that label's value will be shown; otherwise, each of the labels will be
+	// shown as "key:value". To show all labels, specify the single element "*".
+	ShowPprofLabels []string `json:"showPprofLabels,omitempty"`
+
 	// An array of mappings from a local path (client) to the remote path (debugger).
 	// This setting is useful when working in a file system with symbolic links,
 	// running remote debugging, or debugging an executable compiled externally.