Move print goroutine info into command

* DebuggedProcess method: `PrintGoroutinesInfo` -> `GoroutinesInfo`
* `goroutines` command in command/command.go now responsible for
  printing info.

command/command.go

@@ -158,7 +158,21 @@ func thread(p *proctl.DebuggedProcess, args ...string) error {
 }
 
 func goroutines(p *proctl.DebuggedProcess, args ...string) error {
-	return p.PrintGoroutinesInfo()
+	var fname string
+	gs, err := p.GoroutinesInfo()
+	if err != nil {
+		return err
+	}
+
+	fmt.Printf("[%d goroutines]\n", len(gs))
+	for _, g := range gs {
+		if g.Func != nil {
+			fname = g.Func.Name
+		}
+		fmt.Printf("Goroutine %d - %s:%d %s\n", g.Id, g.File, g.Line, fname)
+	}
+
+	return nil
 }
 
 func cont(p *proctl.DebuggedProcess, args ...string) error {

proctl/proctl.go

@@ -5,6 +5,7 @@ package proctl
 import (
 	"debug/dwarf"
 	"debug/gosym"
+	"encoding/binary"
 	"fmt"
 	"os"
 	"os/exec"
@@ -296,7 +297,7 @@ func (dbp *DebuggedProcess) next() error {
 		}
 		// Make sure we're on the same goroutine.
 		// TODO(dp) take into account goroutine exit.
-		if tg.id == curg.id {
+		if tg.Id == curg.Id {
 			if dbp.CurrentThread != thread {
 				dbp.SwitchThread(thread.Id)
 			}
@@ -377,6 +378,34 @@ func (dbp *DebuggedProcess) SwitchThread(tid int) error {
 	return fmt.Errorf("thread %d does not exist", tid)
 }
 
+func (dbp *DebuggedProcess) GoroutinesInfo() ([]*G, error) {
+	var (
+		allg   []*G
+		reader = dbp.dwarf.Reader()
+	)
+
+	allglen, err := allglenval(dbp, reader)
+	if err != nil {
+		return nil, err
+	}
+	reader.Seek(0)
+	allgentryaddr, err := addressFor(dbp, "runtime.allg", reader)
+	if err != nil {
+		return nil, err
+	}
+	faddr, err := dbp.CurrentThread.readMemory(uintptr(allgentryaddr), ptrsize)
+	allgptr := binary.LittleEndian.Uint64(faddr)
+
+	for i := uint64(0); i < allglen; i++ {
+		g, err := parseG(dbp, allgptr+(i*uint64(ptrsize)), reader)
+		if err != nil {
+			return nil, err
+		}
+		allg = append(allg, g)
+	}
+	return allg, nil
+}
+
 // Obtains register values from what Delve considers to be the current
 // thread of the traced process.
 func (dbp *DebuggedProcess) Registers() (Registers, error) {

proctl/variables.go

@@ -3,6 +3,7 @@ package proctl
 import (
 	"bytes"
 	"debug/dwarf"
+	"debug/gosym"
 	"encoding/binary"
 	"fmt"
 	"strconv"
@@ -32,8 +33,11 @@ type M struct {
 }
 
 type G struct {
-	id int
-	pc uint64
+	Id   int
+	PC   uint64
+	File string
+	Line int
+	Func *gosym.Func
 }
 
 const ptrsize uintptr = unsafe.Sizeof(int(1))
@@ -205,37 +209,6 @@ func parseAllMPtr(dbp *DebuggedProcess, reader *dwarf.Reader) (uint64, error) {
 	return uint64(addr), nil
 }
 
-func (dbp *DebuggedProcess) PrintGoroutinesInfo() error {
-	reader := dbp.dwarf.Reader()
-
-	allglen, err := allglenval(dbp, reader)
-	if err != nil {
-		return err
-	}
-	reader.Seek(0)
-	allgentryaddr, err := addressFor(dbp, "runtime.allg", reader)
-	if err != nil {
-		return err
-	}
-	fmt.Printf("[%d goroutines]\n", allglen)
-	faddr, err := dbp.CurrentThread.readMemory(uintptr(allgentryaddr), ptrsize)
-	allg := binary.LittleEndian.Uint64(faddr)
-
-	for i := uint64(0); i < allglen; i++ {
-		g, err := parseG(dbp, allg+(i*uint64(ptrsize)), reader)
-		if err != nil {
-			return err
-		}
-		f, l, fn := dbp.goSymTable.PCToLine(g.pc)
-		fname := ""
-		if fn != nil {
-			fname = fn.Name
-		}
-		fmt.Printf("Goroutine %d - %s:%d %s\n", g.id, f, l, fname)
-	}
-	return nil
-}
-
 func parseG(dbp *DebuggedProcess, addr uint64, reader *dwarf.Reader) (*G, error) {
 	gaddrbytes, err := dbp.CurrentThread.readMemory(uintptr(addr), ptrsize)
 	if err != nil {
@@ -263,7 +236,15 @@ func parseG(dbp *DebuggedProcess, addr uint64, reader *dwarf.Reader) (*G, error)
 		return nil, fmt.Errorf("error reading sched %s", err)
 	}
 	gopc := binary.LittleEndian.Uint64(schedbytes)
-	return &G{id: int(binary.LittleEndian.Uint64(goidbytes)), pc: gopc}, nil
+	f, l, fn := dbp.goSymTable.PCToLine(gopc)
+	g := &G{
+		Id:   int(binary.LittleEndian.Uint64(goidbytes)),
+		PC:   gopc,
+		File: f,
+		Line: l,
+		Func: fn,
+	}
+	return g, nil
 }
 
 func allglenval(dbp *DebuggedProcess, reader *dwarf.Reader) (uint64, error) {