delve/command/command.go
2014-08-23 08:20:56 -05:00

167 lines
3.2 KiB
Go

// Package command implements functions for responding to user
// input and dispatching to appropriate backend commands.
package command
import (
"debug/gosym"
"fmt"
"path/filepath"
"strconv"
"strings"
"github.com/derekparker/dbg/proctl"
)
type cmdfunc func(proc *proctl.DebuggedProcess, args ...string) error
type Commands struct {
cmds map[string]cmdfunc
}
// Returns a Commands struct with default commands defined.
func DebugCommands() *Commands {
cmds := map[string]cmdfunc{
"continue": cont,
"next": next,
"break": breakpoint,
"step": step,
"clear": clear,
"": nullCommand,
}
return &Commands{cmds}
}
// Register custom commands. Expects cf to be a func of type cmdfunc,
// returning only an error.
func (c *Commands) Register(cmdstr string, cf cmdfunc) {
c.cmds[cmdstr] = cf
}
// Find will look up the command function for the given command input.
// If it cannot find the command it will defualt to noCmdAvailable().
// If the command is an empty string it will replay the last command.
func (c *Commands) Find(cmdstr string) cmdfunc {
cmd, ok := c.cmds[cmdstr]
if !ok {
return noCmdAvailable
}
// Allow <enter> to replay last command
c.cmds[""] = cmd
return cmd
}
func CommandFunc(fn func() error) cmdfunc {
return func(p *proctl.DebuggedProcess, args ...string) error {
return fn()
}
}
func noCmdAvailable(p *proctl.DebuggedProcess, ars ...string) error {
return fmt.Errorf("command not available")
}
func nullCommand(p *proctl.DebuggedProcess, ars ...string) error {
return nil
}
func cont(p *proctl.DebuggedProcess, ars ...string) error {
return p.Continue()
}
func step(p *proctl.DebuggedProcess, args ...string) error {
err := p.Step()
if err != nil {
return err
}
regs, err := p.Registers()
if err != nil {
return err
}
f, l, _ := p.GoSymTable.PCToLine(regs.PC())
fmt.Printf("Stopped at: %s:%d\n", f, l)
return nil
}
func next(p *proctl.DebuggedProcess, args ...string) error {
err := p.Next()
if err != nil {
return err
}
regs, err := p.Registers()
if err != nil {
return err
}
f, l, _ := p.GoSymTable.PCToLine(regs.PC())
fmt.Printf("Stopped at: %s:%d\n", f, l)
return nil
}
func clear(p *proctl.DebuggedProcess, args ...string) error {
fname := args[0]
fn := p.GoSymTable.LookupFunc(fname)
if fn == nil {
return fmt.Errorf("No function named %s", fname)
}
bp, err := p.Clear(fn.Entry)
if err != nil {
return err
}
fmt.Printf("Breakpoint cleared at %#v for %s %s:%d\n", bp.Addr, bp.FunctionName, bp.File, bp.Line)
return nil
}
func breakpoint(p *proctl.DebuggedProcess, args ...string) error {
var (
fn *gosym.Func
pc uint64
fname = args[0]
)
if strings.ContainsRune(fname, ':') {
fl := strings.Split(fname, ":")
f, err := filepath.Abs(fl[0])
if err != nil {
return err
}
l, err := strconv.Atoi(fl[1])
if err != nil {
return err
}
pc, fn, err = p.GoSymTable.LineToPC(f, l)
if err != nil {
return err
}
} else {
fn = p.GoSymTable.LookupFunc(fname)
if fn == nil {
return fmt.Errorf("No function named %s", fname)
}
pc = fn.Entry
}
bp, err := p.Break(uintptr(pc))
if err != nil {
return err
}
fmt.Printf("Breakpoint set at %#v for %s %s:%d\n", bp.Addr, bp.FunctionName, bp.File, bp.Line)
return nil
}