terminal,service: better printing of suspended breakpoints (#3415)

Show the location expression that will be used to set a suspended
breakpoint in the breakpoints list.

Also change 'target' called without arguments to print a better error
message and 'target follow-exec' without the last argument to print the
state of follow-exec.

pkg/proc/breakpoints.go

@@ -1018,6 +1018,7 @@ type SetBreakpoint struct {
 	File         string
 	Line         int
 	Expr         func(*Target) []uint64
+	ExprString   string
 	PidAddrs     []PidAddr
 }
 

pkg/terminal/command.go

@@ -1702,8 +1702,15 @@ func breakpoints(t *Term, ctx callContext, args string) error {
 		enabled := "(enabled)"
 		if bp.Disabled {
 			enabled = "(disabled)"
+		} else if bp.ExprString != "" {
+			enabled = "(suspended)"
+		}
+		fmt.Fprintf(t.stdout, "%s %s", formatBreakpointName(bp, true), enabled)
+		if bp.ExprString != "" {
+			fmt.Fprintf(t.stdout, " at %s\n", bp.ExprString)
+		} else {
+			fmt.Fprintf(t.stdout, " at %v (%d)\n", t.formatBreakpointLocation(bp), bp.TotalHitCount)
 		}
-		fmt.Fprintf(t.stdout, "%s %s at %v (%d)\n", formatBreakpointName(bp, true), enabled, t.formatBreakpointLocation(bp), bp.TotalHitCount)
 
 		attrs := formatBreakpointAttrs("\t", bp, false)
 
@@ -3277,7 +3284,12 @@ func target(t *Term, ctx callContext, args string) error {
 		return nil
 	case "follow-exec":
 		if len(argv) == 1 {
-			return errors.New("not enough arguments")
+			if t.client.FollowExecEnabled() {
+				fmt.Fprintf(t.stdout, "Follow exec is enabled.\n")
+			} else {
+				fmt.Fprintf(t.stdout, "Follow exec is disabled.\n")
+			}
+			return nil
 		}
 		argv = config.Split2PartsBySpace(argv[1])
 		switch argv[0] {
@@ -3316,6 +3328,8 @@ func target(t *Term, ctx callContext, args string) error {
 			return fmt.Errorf("could not find target %d", pid)
 		}
 		return nil
+	case "":
+		return errors.New("not enough arguments for 'target'")
 	default:
 		return fmt.Errorf("unknown command 'target %s'", argv[0])
 	}

service/api/conversions.go

@@ -54,8 +54,11 @@ func ConvertLogicalBreakpoint(lbp *proc.LogicalBreakpoint) *Breakpoint {
 }
 
 // ConvertPhysicalBreakpoints adds informations from physical breakpoints to an API breakpoint.
-func ConvertPhysicalBreakpoints(b *Breakpoint, pids []int, bps []*proc.Breakpoint) {
+func ConvertPhysicalBreakpoints(b *Breakpoint, lbp *proc.LogicalBreakpoint, pids []int, bps []*proc.Breakpoint) {
 	if len(bps) == 0 {
+		if lbp != nil {
+			b.ExprString = lbp.Set.ExprString
+		}
 		return
 	}
 

service/api/types.go

@@ -92,6 +92,8 @@ type Breakpoint struct {
 	// FunctionName is the name of the function at the current breakpoint, and
 	// may not always be available.
 	FunctionName string `json:"functionName,omitempty"`
+	// ExprString is the string that will be used to set a suspended breakpoint.
+	ExprString string
 
 	// Breakpoint condition
 	Cond string

service/dap/server.go

@@ -1961,7 +1961,7 @@ func (s *Session) stoppedOnBreakpointGoroutineID(state *api.DebuggerState) (int6
 		return goid, nil
 	}
 	abp := api.ConvertLogicalBreakpoint(bp.Breakpoint.Logical)
-	api.ConvertPhysicalBreakpoints(abp, []int{0}, []*proc.Breakpoint{bp.Breakpoint})
+	api.ConvertPhysicalBreakpoints(abp, bp.Breakpoint.Logical, []int{0}, []*proc.Breakpoint{bp.Breakpoint})
 	return goid, abp
 }
 

service/debugger/debugger.go

@@ -617,7 +617,7 @@ func (d *Debugger) state(retLoadCfg *proc.LoadConfig, withBreakpointInfo bool) (
 	for t.Next() {
 		for _, bp := range t.Breakpoints().WatchOutOfScope {
 			abp := api.ConvertLogicalBreakpoint(bp.Logical)
-			api.ConvertPhysicalBreakpoints(abp, []int{t.Pid()}, []*proc.Breakpoint{bp})
+			api.ConvertPhysicalBreakpoints(abp, bp.Logical, []int{t.Pid()}, []*proc.Breakpoint{bp})
 			state.WatchOutOfScope = append(state.WatchOutOfScope, abp)
 		}
 	}
@@ -744,6 +744,7 @@ func (d *Debugger) CreateBreakpoint(requestedBp *api.Breakpoint, locExpr string,
 			}
 			return locs[0].PCs
 		}
+		setbp.ExprString = locExpr
 	}
 
 	id := requestedBp.ID
@@ -805,7 +806,7 @@ func (d *Debugger) convertBreakpoint(lbp *proc.LogicalBreakpoint) *api.Breakpoin
 			}
 		}
 	}
-	api.ConvertPhysicalBreakpoints(abp, pids, bps)
+	api.ConvertPhysicalBreakpoints(abp, lbp, pids, bps)
 	return abp
 }
 
@@ -1039,7 +1040,7 @@ func (d *Debugger) Breakpoints(all bool) []*api.Breakpoint {
 				} else {
 					abp = &api.Breakpoint{}
 				}
-				api.ConvertPhysicalBreakpoints(abp, []int{t.Pid()}, []*proc.Breakpoint{bp})
+				api.ConvertPhysicalBreakpoints(abp, bp.Logical, []int{t.Pid()}, []*proc.Breakpoint{bp})
 				abp.VerboseDescr = bp.VerboseDescr()
 				abps = append(abps, abp)
 			}