// 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 ptrace

import (
	"os";
	"strconv";
	"syscall";
)

type amd64Regs struct {
	syscall.PtraceRegs;
	setter func (*syscall.PtraceRegs) os.Error;
}

var names = [...]string {
	"rax",
	"rbx",
	"rcx",
	"rdx",
	"rsi",
	"rdi",
	"rbp",
	"rsp",
	"r8",
	"r9",
	"r10",
	"r11",
	"r12",
	"r13",
	"r14",
	"r15",
	"rip",
	"eflags",
	"cs",
	"ss",
	"ds",
	"es",
	"fs",
	"gs",

	// PtraceRegs contains these registers, but I don't think
	// they're actually meaningful.
	//"orig_rax",
	//"fs_base",
	//"gs_base",
}

func (r *amd64Regs) PC() Word {
	return Word(r.Rip);
}

func (r *amd64Regs) SetPC(val Word) os.Error {
	r.Rip = uint64(val);
	return r.setter(&r.PtraceRegs);
}

func (r *amd64Regs) Link() Word {
	// TODO(austin)
	panic("No link register");
}

func (r *amd64Regs) SetLink(val Word) os.Error {
	panic("No link register");
}

func (r *amd64Regs) SP() Word {
	return Word(r.Rsp);
}

func (r *amd64Regs) SetSP(val Word) os.Error {
	r.Rsp = uint64(val);
	return r.setter(&r.PtraceRegs);
}

func (r *amd64Regs) Names() []string {
	return &names;
}

func (r *amd64Regs) Get(i int) Word {
	switch i {
	case 0: return Word(r.Rax);
	case 1: return Word(r.Rbx);
	case 2: return Word(r.Rcx);
	case 3: return Word(r.Rdx);
	case 4: return Word(r.Rsi);
	case 5: return Word(r.Rdi);
	case 6: return Word(r.Rbp);
	case 7: return Word(r.Rsp);
	case 8: return Word(r.R8);
	case 9: return Word(r.R9);
	case 10: return Word(r.R10);
	case 11: return Word(r.R11);
	case 12: return Word(r.R12);
	case 13: return Word(r.R13);
	case 14: return Word(r.R14);
	case 15: return Word(r.R15);
	case 16: return Word(r.Rip);
	case 17: return Word(r.Eflags);
	case 18: return Word(r.Cs);
	case 19: return Word(r.Ss);
	case 20: return Word(r.Ds);
	case 21: return Word(r.Es);
	case 22: return Word(r.Fs);
	case 23: return Word(r.Gs);
	}
	panic("invalid register index ", strconv.Itoa(i));
}

func (r *amd64Regs) Set(i int, val Word) os.Error {
	switch i {
	case 0: r.Rax = uint64(val);
	case 1: r.Rbx = uint64(val);
	case 2: r.Rcx = uint64(val);
	case 3: r.Rdx = uint64(val);
	case 4: r.Rsi = uint64(val);
	case 5: r.Rdi = uint64(val);
	case 6: r.Rbp = uint64(val);
	case 7: r.Rsp = uint64(val);
	case 8: r.R8 = uint64(val);
	case 9: r.R9 = uint64(val);
	case 10: r.R10 = uint64(val);
	case 11: r.R11 = uint64(val);
	case 12: r.R12 = uint64(val);
	case 13: r.R13 = uint64(val);
	case 14: r.R14 = uint64(val);
	case 15: r.R15 = uint64(val);
	case 16: r.Rip = uint64(val);
	case 17: r.Eflags = uint64(val);
	case 18: r.Cs = uint64(val);
	case 19: r.Ss = uint64(val);
	case 20: r.Ds = uint64(val);
	case 21: r.Es = uint64(val);
	case 22: r.Fs = uint64(val);
	case 23: r.Gs = uint64(val);
	default:
		panic("invalid register index ", strconv.Itoa(i));
	}
	return r.setter(&r.PtraceRegs);
}

func newRegs(regs *syscall.PtraceRegs, setter func (*syscall.PtraceRegs) os.Error) Regs {
	res := amd64Regs{};
	res.PtraceRegs = *regs;
	res.setter = setter;
	return &res;
}