Handle runtime.Breakpoint

_fixtures/testruntimebreakpoint.go

@@ -0,0 +1,11 @@
+package main
+
+import (
+	"fmt"
+	"runtime"
+)
+
+func main() {
+	runtime.Breakpoint()
+	fmt.Println("broke")
+}

proctl/proctl.go

@@ -554,6 +554,17 @@ func (dbp *DebuggedProcess) handleBreakpointOnThread(id int) (*ThreadContext, er
 	if dbp.halt {
 		return thread, nil
 	}
+	fn := dbp.goSymTable.PCToFunc(pc)
+	if fn != nil && fn.Name == "runtime.breakpoint" {
+		dbp.singleStep = true
+		defer func() { dbp.singleStep = false }()
+		for i := 0; i < 2; i++ {
+			if err := thread.Step(); err != nil {
+				return nil, err
+			}
+		}
+		return thread, nil
+	}
 	return nil, NoBreakPointError{addr: pc}
 }
 

proctl/proctl_test.go

@@ -294,6 +294,24 @@ func TestNextFunctionReturn(t *testing.T) {
 	testnext(testcases, "main.helloworld", t)
 }
 
+func TestRuntimeBreakpoint(t *testing.T) {
+	var testfile, _ = filepath.Abs("../_fixtures/testruntimebreakpoint")
+	withTestProcess(testfile, t, func(p *DebuggedProcess) {
+		err := p.Continue()
+		if err != nil {
+			t.Fatal(err)
+		}
+		pc, err := p.PC()
+		if err != nil {
+			t.Fatal(err)
+		}
+		_, l, _ := p.PCToLine(pc)
+		if l != 10 {
+			t.Fatal("did not respect breakpoint")
+		}
+	})
+}
+
 func TestFindReturnAddress(t *testing.T) {
 	var testfile, _ = filepath.Abs("../_fixtures/testnextprog")