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// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package ogle
import (
"debug/proc"
"math"
)
type Arch interface {
// ToWord converts an array of up to 8 bytes in memory order
// to a word.
ToWord(data []byte) proc.Word
// FromWord converts a word to an array of up to 8 bytes in
// memory order.
FromWord(v proc.Word, out []byte)
// ToFloat32 converts a word to a float. The order of this
// word will be the order returned by ToWord on the memory
// representation of a float, and thus may require reversing.
ToFloat32(bits uint32) float32
// FromFloat32 converts a float to a word. This should return
// a word that can be passed to FromWord to get the memory
// representation of a float on this architecture.
FromFloat32(f float32) uint32
// ToFloat64 is to float64 as ToFloat32 is to float32.
ToFloat64(bits uint64) float64
// FromFloat64 is to float64 as FromFloat32 is to float32.
FromFloat64(f float64) uint64
// IntSize returns the number of bytes in an 'int'.
IntSize() int
// PtrSize returns the number of bytes in a 'uintptr'.
PtrSize() int
// FloatSize returns the number of bytes in a 'float'.
FloatSize() int
// Align rounds offset up to the appropriate offset for a
// basic type with the given width.
Align(offset, width int) int
// G returns the current G pointer.
G(regs proc.Regs) proc.Word
// ClosureSize returns the number of bytes expected by
// ParseClosure.
ClosureSize() int
// ParseClosure takes ClosureSize bytes read from a return PC
// in a remote process, determines if the code is a closure,
// and returns the frame size of the closure if it is.
ParseClosure(data []byte) (frame int, ok bool)
}
type ArchLSB struct{}
func (ArchLSB) ToWord(data []byte) proc.Word {
var v proc.Word
for i, b := range data {
v |= proc.Word(b) << (uint(i) * 8)
}
return v
}
func (ArchLSB) FromWord(v proc.Word, out []byte) {
for i := range out {
out[i] = byte(v)
v >>= 8
}
}
func (ArchLSB) ToFloat32(bits uint32) float32 {
// TODO(austin) Do these definitions depend on my current
// architecture?
return math.Float32frombits(bits)
}
func (ArchLSB) FromFloat32(f float32) uint32 { return math.Float32bits(f) }
func (ArchLSB) ToFloat64(bits uint64) float64 { return math.Float64frombits(bits) }
func (ArchLSB) FromFloat64(f float64) uint64 { return math.Float64bits(f) }
type ArchAlignedMultiple struct{}
func (ArchAlignedMultiple) Align(offset, width int) int {
return ((offset - 1) | (width - 1)) + 1
}
type amd64 struct {
ArchLSB
ArchAlignedMultiple
gReg int
}
func (a *amd64) IntSize() int { return 4 }
func (a *amd64) PtrSize() int { return 8 }
func (a *amd64) FloatSize() int { return 4 }
func (a *amd64) G(regs proc.Regs) proc.Word {
// See src/pkg/runtime/mkasmh
if a.gReg == -1 {
ns := regs.Names()
for i, n := range ns {
if n == "r15" {
a.gReg = i
break
}
}
}
return regs.Get(a.gReg)
}
func (a *amd64) ClosureSize() int { return 8 }
func (a *amd64) ParseClosure(data []byte) (int, bool) {
if data[0] == 0x48 && data[1] == 0x81 && data[2] == 0xc4 && data[7] == 0xc3 {
return int(a.ToWord(data[3:7]) + 8), true
}
return 0, false
}
var Amd64 = &amd64{gReg: -1}