delve/proc/stack.go
2015-06-20 15:29:33 -05:00

86 lines
2.2 KiB
Go

package proc
import (
"encoding/binary"
)
// Takes an offset from RSP and returns the address of the
// instruction the currect function is going to return to.
func (thread *Thread) ReturnAddress() (uint64, error) {
locations, err := thread.Stacktrace(1)
if err != nil {
return 0, err
}
return locations[0].PC, nil
}
// Returns the stack trace for thread
// Note that it doesn't include the current frame and the locations in the array are return addresses not call addresses
func (thread *Thread) Stacktrace(depth int) ([]Location, error) {
regs, err := thread.Registers()
if err != nil {
return nil, err
}
locations, err := thread.dbp.stacktrace(regs.PC(), regs.SP(), depth)
if err != nil {
return nil, err
}
return locations, nil
}
// Returns the stack trace for a goroutine
// Note that it doesn't include the current frame and the locations in the array are return addresses not call addresses
func (dbp *DebuggedProcess) GoroutineStacktrace(g *G, depth int) ([]Location, error) {
if g.thread != nil {
return g.thread.Stacktrace(depth)
}
return dbp.stacktrace(g.PC, g.SP, depth)
}
func (dbp *DebuggedProcess) GoroutineLocation(g *G) *Location {
f, l, fn := dbp.PCToLine(g.PC)
return &Location{PC: g.PC, File: f, Line: l, Fn: fn}
}
type NullAddrError struct{}
func (n NullAddrError) Error() string {
return "NULL address"
}
func (dbp *DebuggedProcess) stacktrace(pc, sp uint64, depth int) ([]Location, error) {
var (
ret = pc
data = make([]byte, dbp.arch.PtrSize())
btoffset int64
locations []Location
retaddr uintptr
)
for i := int64(0); i < int64(depth); i++ {
fde, err := dbp.frameEntries.FDEForPC(ret)
if err != nil {
return nil, err
}
btoffset += fde.ReturnAddressOffset(ret)
retaddr = uintptr(int64(sp) + btoffset + (i * int64(dbp.arch.PtrSize())))
if retaddr == 0 {
return nil, NullAddrError{}
}
_, err = readMemory(dbp.CurrentThread, retaddr, data)
if err != nil {
return nil, err
}
ret = binary.LittleEndian.Uint64(data)
if ret <= 0 {
break
}
f, l, fn := dbp.goSymTable.PCToLine(ret)
locations = append(locations, Location{PC: ret, File: f, Line: l, Fn: fn})
if fn != nil && fn.Name == "runtime.goexit" {
break
}
}
return locations, nil
}