Debugger architecture interface and definitions for AMD64.

R=rsc
APPROVED=rsc
DELTA=114  (114 added, 0 deleted, 0 changed)
OCL=33957
CL=33962

usr/austin/ogle/arch.go

+// 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 (
+	"math";
+	"ptrace";
+)
+
+type Arch interface {
+	// ToWord converts an array of up to 8 bytes in memory order
+	// to a word.
+	ToWord(data []byte) ptrace.Word;
+	// FromWord converts a word to an array of up to 8 bytes in
+	// memory order.
+	FromWord(v ptrace.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 ptrace.Regs) ptrace.Word;
+}
+
+type ArchLSB struct {}
+
+func (ArchLSB) ToWord(data []byte) ptrace.Word {
+	var v ptrace.Word;
+	for i, b := range data {
+		v |= ptrace.Word(b) << (uint(i)*8);
+	}
+	return v;
+}
+
+func (ArchLSB) FromWord(v ptrace.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 ptrace.Regs) ptrace.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);
+}
+
+var Amd64 = &amd64{gReg: -1};