proc: convert Arch into a struct (#1972)

Replace the interface type Arch with a struct with the same
functionality.

pkg/proc/amd64_arch.go

@@ -12,23 +12,6 @@ import (
 	"github.com/go-delve/delve/pkg/dwarf/op"
 )
 
-// AMD64 represents the AMD64 CPU architecture.
-type AMD64 struct {
-	gStructOffset uint64
-	goos          string
-
-	// crosscall2fn is the DIE of crosscall2, a function used by the go runtime
-	// to call C functions. This function in go 1.9 (and previous versions) had
-	// a bad frame descriptor which needs to be fixed to generate good stack
-	// traces.
-	crosscall2fn *Function
-
-	// sigreturnfn is the DIE of runtime.sigreturn, the return trampoline for
-	// the signal handler. See comment in FixFrameUnwindContext for a
-	// description of why this is needed.
-	sigreturnfn *Function
-}
-
 const (
 	amd64DwarfIPRegNum uint64 = 16
 	amd64DwarfSPRegNum uint64 = 7
@@ -39,51 +22,28 @@ var amd64BreakInstruction = []byte{0xCC}
 
 // AMD64Arch returns an initialized AMD64
 // struct.
-func AMD64Arch(goos string) *AMD64 {
-	return &AMD64{
-		goos: goos,
+func AMD64Arch(goos string) *Arch {
+	return &Arch{
+		Name:                             "amd64",
+		ptrSize:                          8,
+		maxInstructionLength:             15,
+		breakpointInstruction:            amd64BreakInstruction,
+		breakInstrMovesPC:                true,
+		derefTLS:                         goos == "windows",
+		prologues:                        prologuesAMD64,
+		fixFrameUnwindContext:            amd64FixFrameUnwindContext,
+		switchStack:                      amd64SwitchStack,
+		regSize:                          amd64RegSize,
+		RegistersToDwarfRegisters:        amd64RegistersToDwarfRegisters,
+		addrAndStackRegsToDwarfRegisters: amd64AddrAndStackRegsToDwarfRegisters,
+		DwarfRegisterToString:            amd64DwarfRegisterToString,
+		inhibitStepInto:                  func(*BinaryInfo, uint64) bool { return false },
+		asmDecode:                        amd64AsmDecode,
 	}
 }
 
-// PtrSize returns the size of a pointer
-// on this architecture.
-func (a *AMD64) PtrSize() int {
-	return 8
-}
-
-// MaxInstructionLength returns the maximum length of an instruction.
-func (a *AMD64) MaxInstructionLength() int {
-	return 15
-}
-
-// BreakpointInstruction returns the Breakpoint
-// instruction for this architecture.
-func (a *AMD64) BreakpointInstruction() []byte {
-	return amd64BreakInstruction
-}
-
-// BreakInstrMovesPC returns whether the
-// breakpoint instruction will change the value
-// of PC after being executed
-func (a *AMD64) BreakInstrMovesPC() bool {
-	return true
-}
-
-// BreakpointSize returns the size of the
-// breakpoint instruction on this architecture.
-func (a *AMD64) BreakpointSize() int {
-	return len(amd64BreakInstruction)
-}
-
-// DerefTLS returns true if the value of regs.TLS()+GStructOffset() is a
-// pointer to the G struct
-func (a *AMD64) DerefTLS() bool {
-	return a.goos == "windows"
-}
-
-// FixFrameUnwindContext adds default architecture rules to fctxt or returns
-// the default frame unwind context if fctxt is nil.
-func (a *AMD64) FixFrameUnwindContext(fctxt *frame.FrameContext, pc uint64, bi *BinaryInfo) *frame.FrameContext {
+func amd64FixFrameUnwindContext(fctxt *frame.FrameContext, pc uint64, bi *BinaryInfo) *frame.FrameContext {
+	a := bi.Arch
 	if a.sigreturnfn == nil {
 		a.sigreturnfn = bi.LookupFunc["runtime.sigreturn"]
 	}
@@ -138,7 +98,7 @@ func (a *AMD64) FixFrameUnwindContext(fctxt *frame.FrameContext, pc uint64, bi *
 	if a.crosscall2fn != nil && pc >= a.crosscall2fn.Entry && pc < a.crosscall2fn.End {
 		rule := fctxt.CFA
 		if rule.Offset == crosscall2SPOffsetBad {
-			switch a.goos {
+			switch bi.GOOS {
 			case "windows":
 				rule.Offset += crosscall2SPOffsetWindows
 			default:
@@ -168,10 +128,7 @@ func (a *AMD64) FixFrameUnwindContext(fctxt *frame.FrameContext, pc uint64, bi *
 // switch happens.
 const amd64cgocallSPOffsetSaveSlot = 0x28
 
-// SwitchStack will use the current frame to determine if it's time to
-// switch between the system stack and the goroutine stack or vice versa.
-// Sets it.atend when the top of the stack is reached.
-func (a *AMD64) SwitchStack(it *stackIterator, _ *op.DwarfRegisters) bool {
+func amd64SwitchStack(it *stackIterator, _ *op.DwarfRegisters) bool {
 	if it.frame.Current.Fn == nil {
 		return false
 	}
@@ -282,12 +239,12 @@ func (a *AMD64) SwitchStack(it *stackIterator, _ *op.DwarfRegisters) bool {
 	}
 }
 
-// RegSize returns the size (in bytes) of register regnum.
+// amd64RegSize returns the size (in bytes) of register regnum.
 // The mapping between hardware registers and DWARF registers is specified
 // in the System V ABI AMD64 Architecture Processor Supplement page 57,
 // figure 3.36
 // https://www.uclibc.org/docs/psABI-x86_64.pdf
-func (a *AMD64) RegSize(regnum uint64) int {
+func amd64RegSize(regnum uint64) int {
 	// XMM registers
 	if regnum > amd64DwarfIPRegNum && regnum <= 32 {
 		return 16
@@ -387,9 +344,7 @@ func maxAmd64DwarfRegister() int {
 	return max
 }
 
-// RegistersToDwarfRegisters converts hardware registers to the format used
-// by the DWARF expression interpreter.
-func (a *AMD64) RegistersToDwarfRegisters(staticBase uint64, regs Registers) op.DwarfRegisters {
+func amd64RegistersToDwarfRegisters(staticBase uint64, regs Registers) op.DwarfRegisters {
 	dregs := make([]*op.DwarfRegister, maxAmd64DwarfRegister()+1)
 
 	for _, reg := range regs.Slice(true) {
@@ -408,9 +363,7 @@ func (a *AMD64) RegistersToDwarfRegisters(staticBase uint64, regs Registers) op.
 	}
 }
 
-// AddrAndStackRegsToDwarfRegisters returns DWARF registers from the passed in
-// PC, SP, and BP registers in the format used by the DWARF expression interpreter.
-func (a *AMD64) AddrAndStackRegsToDwarfRegisters(staticBase, pc, sp, bp, lr uint64) op.DwarfRegisters {
+func amd64AddrAndStackRegsToDwarfRegisters(staticBase, pc, sp, bp, lr uint64) op.DwarfRegisters {
 	dregs := make([]*op.DwarfRegister, amd64DwarfIPRegNum+1)
 	dregs[amd64DwarfIPRegNum] = op.DwarfRegisterFromUint64(pc)
 	dregs[amd64DwarfSPRegNum] = op.DwarfRegisterFromUint64(sp)
@@ -426,8 +379,7 @@ func (a *AMD64) AddrAndStackRegsToDwarfRegisters(staticBase, pc, sp, bp, lr uint
 	}
 }
 
-// DwarfRegisterToString returns the name and value representation of the given register.
-func (a *AMD64) DwarfRegisterToString(i int, reg *op.DwarfRegister) (name string, floatingPoint bool, repr string) {
+func amd64DwarfRegisterToString(i int, reg *op.DwarfRegister) (name string, floatingPoint bool, repr string) {
 	name, ok := amd64DwarfToName[i]
 	if !ok {
 		name = fmt.Sprintf("unknown%d", i)
@@ -559,9 +511,3 @@ func formatX87Reg(b []byte) string {
 
 	return fmt.Sprintf("%#04x%016x\t%g", exponent, mantissa, f)
 }
-
-// InhibitStepInto returns whether StepBreakpoint can be set at pc.
-// Always return false on amd64.
-func (a *AMD64) InhibitStepInto(bi *BinaryInfo, pc uint64) bool {
-	return false
-}

pkg/proc/amd64_disasm.go

@@ -8,16 +8,10 @@ import (
 	"golang.org/x/arch/x86/x86asm"
 )
 
-// AsmDecode decodes the assembly instruction starting at mem[0:] into asmInst.
-// It assumes that the Loc and AtPC fields of asmInst have already been filled.
-func (a *AMD64) AsmDecode(asmInst *AsmInstruction, mem []byte, regs Registers, memrw MemoryReadWriter, bi *BinaryInfo) error {
+func amd64AsmDecode(asmInst *AsmInstruction, mem []byte, regs Registers, memrw MemoryReadWriter, bi *BinaryInfo) error {
 	return x86AsmDecode(asmInst, mem, regs, memrw, bi, 64)
 }
 
-func (a *AMD64) Prologues() []opcodeSeq {
-	return prologuesAMD64
-}
-
 // Possible stacksplit prologues are inserted by stacksplit in
 // $GOROOT/src/cmd/internal/obj/x86/obj6.go.
 // The stacksplit prologue will always begin with loading curg in CX, this

pkg/proc/arch.go

@@ -5,47 +5,87 @@ import (
 	"github.com/go-delve/delve/pkg/dwarf/op"
 )
 
-// Arch defines an interface for representing a
-// CPU architecture.
-type Arch interface {
-	// PtrSize returns the size of a pointer for the architecture.
-	PtrSize() int
-	// MaxInstructionLength is the maximum size in bytes of an instruction.
-	MaxInstructionLength() int
-	// AsmDecode decodes the assembly instruction starting at mem[0:] into asmInst.
+// Arch represents a CPU architecture.
+type Arch struct {
+	Name string // architecture name
+
+	ptrSize               int
+	maxInstructionLength  int
+	prologues             []opcodeSeq
+	breakpointInstruction []byte
+	breakInstrMovesPC     bool
+	derefTLS              bool
+
+	// asmDecode decodes the assembly instruction starting at mem[0:] into asmInst.
 	// It assumes that the Loc and AtPC fields of asmInst have already been filled.
-	AsmDecode(asmInst *AsmInstruction, mem []byte, regs Registers, memrw MemoryReadWriter, bi *BinaryInfo) error
-	// Prologues returns a list of stack split prologues
-	// that are inserted at function entry.
-	Prologues() []opcodeSeq
-	// BreakpointInstruction is the instruction that will trigger a breakpoint trap for
-	// the given architecture.
-	BreakpointInstruction() []byte
-	// BreakInstrMovesPC is true if hitting the breakpoint instruction advances the
-	// instruction counter by the size of the breakpoint instruction.
-	BreakInstrMovesPC() bool
-	// BreakpointSize is the size of the breakpoint instruction for the given architecture.
-	BreakpointSize() int
-	// DerefTLS is true if the G struct stored in the TLS section is a pointer
-	// and the address must be dereferenced to find to actual G struct.
-	DerefTLS() bool
-	// FixFrameUnwindContext applies architecture specific rules for unwinding a stack frame
+	asmDecode func(asmInst *AsmInstruction, mem []byte, regs Registers, memrw MemoryReadWriter, bi *BinaryInfo) error
+	// fixFrameUnwindContext applies architecture specific rules for unwinding a stack frame
 	// on the given arch.
-	FixFrameUnwindContext(*frame.FrameContext, uint64, *BinaryInfo) *frame.FrameContext
-	// SwitchStack will use the current frame to determine if it's time to
+	fixFrameUnwindContext func(*frame.FrameContext, uint64, *BinaryInfo) *frame.FrameContext
+	// switchStack will use the current frame to determine if it's time to
 	// switch between the system stack and the goroutine stack or vice versa.
-	SwitchStack(it *stackIterator, callFrameRegs *op.DwarfRegisters) bool
-	// RegSize returns the size (in bytes) of register regnum.
-	RegSize(uint64) int
+	switchStack func(it *stackIterator, callFrameRegs *op.DwarfRegisters) bool
+	// regSize returns the size (in bytes) of register regnum.
+	regSize func(uint64) int
 	// RegistersToDwarfRegisters maps hardware registers to DWARF registers.
-	RegistersToDwarfRegisters(uint64, Registers) op.DwarfRegisters
-	// AddrAndStackRegsToDwarfRegisters returns DWARF registers from the passed in
+	RegistersToDwarfRegisters func(uint64, Registers) op.DwarfRegisters
+	// addrAndStackRegsToDwarfRegisters returns DWARF registers from the passed in
 	// PC, SP, and BP registers in the format used by the DWARF expression interpreter.
-	AddrAndStackRegsToDwarfRegisters(uint64, uint64, uint64, uint64, uint64) op.DwarfRegisters
+	addrAndStackRegsToDwarfRegisters func(uint64, uint64, uint64, uint64, uint64) op.DwarfRegisters
 	// DwarfRegisterToString returns the name and value representation of the given register.
-	DwarfRegisterToString(int, *op.DwarfRegister) (string, bool, string)
-	// InhibitStepInto returns whether StepBreakpoint can be set at pc.
-	InhibitStepInto(bi *BinaryInfo, pc uint64) bool
+	DwarfRegisterToString func(int, *op.DwarfRegister) (string, bool, string)
+	// inhibitStepInto returns whether StepBreakpoint can be set at pc.
+	inhibitStepInto func(bi *BinaryInfo, pc uint64) bool
+
+	// crosscall2fn is the DIE of crosscall2, a function used by the go runtime
+	// to call C functions. This function in go 1.9 (and previous versions) had
+	// a bad frame descriptor which needs to be fixed to generate good stack
+	// traces.
+	crosscall2fn *Function
+
+	// sigreturnfn is the DIE of runtime.sigreturn, the return trampoline for
+	// the signal handler. See comment in FixFrameUnwindContext for a
+	// description of why this is needed.
+	sigreturnfn *Function
+}
+
+// PtrSize returns the size of a pointer for the architecture.
+func (a *Arch) PtrSize() int {
+	return a.ptrSize
+}
+
+// MaxInstructionLength is the maximum size in bytes of an instruction.
+func (a *Arch) MaxInstructionLength() int {
+	return a.maxInstructionLength
+}
+
+// Prologues returns a list of stack split prologues
+// that are inserted at function entry.
+func (a *Arch) Prologues() []opcodeSeq {
+	return a.prologues
+}
+
+// BreakpointInstruction is the instruction that will trigger a breakpoint trap for
+// the given architecture.
+func (a *Arch) BreakpointInstruction() []byte {
+	return a.breakpointInstruction
+}
+
+// BreakInstrMovesPC is true if hitting the breakpoint instruction advances the
+// instruction counter by the size of the breakpoint instruction.
+func (a *Arch) BreakInstrMovesPC() bool {
+	return a.breakInstrMovesPC
+}
+
+// BreakpointSize is the size of the breakpoint instruction for the given architecture.
+func (a *Arch) BreakpointSize() int {
+	return len(a.breakpointInstruction)
+}
+
+// DerefTLS is true if the G struct stored in the TLS section is a pointer
+// and the address must be dereferenced to find to actual G struct.
+func (a *Arch) DerefTLS() bool {
+	return a.derefTLS
 }
 
 // crosscall2 is defined in $GOROOT/src/runtime/cgo/asm_amd64.s.

pkg/proc/arm64_arch.go

@@ -12,23 +12,6 @@ import (
 	"golang.org/x/arch/arm64/arm64asm"
 )
 
-// ARM64 represents the ARM64 CPU architecture.
-type ARM64 struct {
-	gStructOffset uint64
-	goos          string
-
-	// crosscall2fn is the DIE of crosscall2, a function used by the go runtime
-	// to call C functions. This function in go 1.9 (and previous versions) had
-	// a bad frame descriptor which needs to be fixed to generate good stack
-	// traces.
-	crosscall2fn *Function
-
-	// sigreturnfn is the DIE of runtime.sigreturn, the return trampoline for
-	// the signal handler. See comment in FixFrameUnwindContext for a
-	// description of why this is needed.
-	sigreturnfn *Function
-}
-
 const (
 	arm64DwarfIPRegNum uint64 = 32
 	arm64DwarfSPRegNum uint64 = 31
@@ -40,50 +23,28 @@ var arm64BreakInstruction = []byte{0x0, 0x0, 0x20, 0xd4}
 
 // ARM64Arch returns an initialized ARM64
 // struct.
-func ARM64Arch(goos string) *ARM64 {
-	return &ARM64{
-		goos: goos,
+func ARM64Arch(goos string) *Arch {
+	return &Arch{
+		Name:                             "arm64",
+		ptrSize:                          8,
+		maxInstructionLength:             4,
+		breakpointInstruction:            arm64BreakInstruction,
+		breakInstrMovesPC:                false,
+		derefTLS:                         false,
+		prologues:                        prologuesARM64,
+		fixFrameUnwindContext:            arm64FixFrameUnwindContext,
+		switchStack:                      arm64SwitchStack,
+		regSize:                          arm64RegSize,
+		RegistersToDwarfRegisters:        arm64RegistersToDwarfRegisters,
+		addrAndStackRegsToDwarfRegisters: arm64AddrAndStackRegsToDwarfRegisters,
+		DwarfRegisterToString:            arm64DwarfRegisterToString,
+		inhibitStepInto:                  func(*BinaryInfo, uint64) bool { return false },
+		asmDecode:                        arm64AsmDecode,
 	}
 }
 
-// PtrSize returns the size of a pointer
-// on this architecture.
-func (a *ARM64) PtrSize() int {
-	return 8
-}
-
-// MaxInstructionLength returns the maximum length of an instruction.
-func (a *ARM64) MaxInstructionLength() int {
-	return 4
-}
-
-// BreakpointInstruction returns the Breakpoint
-// instruction for this architecture.
-func (a *ARM64) BreakpointInstruction() []byte {
-	return arm64BreakInstruction
-}
-
-// BreakInstrMovesPC returns whether the
-// breakpoint instruction will change the value
-// of PC after being executed
-func (a *ARM64) BreakInstrMovesPC() bool {
-	return false
-}
-
-// BreakpointSize returns the size of the
-// breakpoint instruction on this architecture.
-func (a *ARM64) BreakpointSize() int {
-	return len(arm64BreakInstruction)
-}
-
-// Always return false for now.
-func (a *ARM64) DerefTLS() bool {
-	return false
-}
-
-// FixFrameUnwindContext adds default architecture rules to fctxt or returns
-// the default frame unwind context if fctxt is nil.
-func (a *ARM64) FixFrameUnwindContext(fctxt *frame.FrameContext, pc uint64, bi *BinaryInfo) *frame.FrameContext {
+func arm64FixFrameUnwindContext(fctxt *frame.FrameContext, pc uint64, bi *BinaryInfo) *frame.FrameContext {
+	a := bi.Arch
 	if a.sigreturnfn == nil {
 		a.sigreturnfn = bi.LookupFunc["runtime.sigreturn"]
 	}
@@ -138,7 +99,7 @@ func (a *ARM64) FixFrameUnwindContext(fctxt *frame.FrameContext, pc uint64, bi *
 	if a.crosscall2fn != nil && pc >= a.crosscall2fn.Entry && pc < a.crosscall2fn.End {
 		rule := fctxt.CFA
 		if rule.Offset == crosscall2SPOffsetBad {
-			switch a.goos {
+			switch bi.GOOS {
 			case "windows":
 				rule.Offset += crosscall2SPOffsetWindows
 			default:
@@ -174,7 +135,7 @@ const arm64cgocallSPOffsetSaveSlot = 0x8
 const prevG0schedSPOffsetSaveSlot = 0x10
 const spAlign = 16
 
-func (a *ARM64) SwitchStack(it *stackIterator, callFrameRegs *op.DwarfRegisters) bool {
+func arm64SwitchStack(it *stackIterator, callFrameRegs *op.DwarfRegisters) bool {
 	if it.frame.Current.Fn != nil {
 		switch it.frame.Current.Fn.Name {
 		case "runtime.asmcgocall", "runtime.cgocallback_gofunc", "runtime.sigpanic":
@@ -270,7 +231,7 @@ func (a *ARM64) SwitchStack(it *stackIterator, callFrameRegs *op.DwarfRegisters)
 	return false
 }
 
-func (a *ARM64) RegSize(regnum uint64) int {
+func arm64RegSize(regnum uint64) int {
 	// fp registers
 	if regnum >= 64 && regnum <= 95 {
 		return 16
@@ -361,9 +322,7 @@ func maxArm64DwarfRegister() int {
 	return max
 }
 
-// RegistersToDwarfRegisters converts hardware registers to the format used
-// by the DWARF expression interpreter.
-func (a *ARM64) RegistersToDwarfRegisters(staticBase uint64, regs Registers) op.DwarfRegisters {
+func arm64RegistersToDwarfRegisters(staticBase uint64, regs Registers) op.DwarfRegisters {
 	dregs := make([]*op.DwarfRegister, maxArm64DwarfRegister()+1)
 
 	dregs[arm64DwarfIPRegNum] = op.DwarfRegisterFromUint64(regs.PC())
@@ -391,9 +350,7 @@ func (a *ARM64) RegistersToDwarfRegisters(staticBase uint64, regs Registers) op.
 	}
 }
 
-// AddrAndStackRegsToDwarfRegisters returns DWARF registers from the passed in
-// PC, SP, and BP registers in the format used by the DWARF expression interpreter.
-func (a *ARM64) AddrAndStackRegsToDwarfRegisters(staticBase, pc, sp, bp, lr uint64) op.DwarfRegisters {
+func arm64AddrAndStackRegsToDwarfRegisters(staticBase, pc, sp, bp, lr uint64) op.DwarfRegisters {
 	dregs := make([]*op.DwarfRegister, arm64DwarfIPRegNum+1)
 	dregs[arm64DwarfIPRegNum] = op.DwarfRegisterFromUint64(pc)
 	dregs[arm64DwarfSPRegNum] = op.DwarfRegisterFromUint64(sp)
@@ -411,7 +368,7 @@ func (a *ARM64) AddrAndStackRegsToDwarfRegisters(staticBase, pc, sp, bp, lr uint
 	}
 }
 
-func (a *ARM64) DwarfRegisterToString(i int, reg *op.DwarfRegister) (name string, floatingPoint bool, repr string) {
+func arm64DwarfRegisterToString(i int, reg *op.DwarfRegister) (name string, floatingPoint bool, repr string) {
 	// see arm64DwarfToHardware table for explanation
 	switch {
 	case i <= 30:
@@ -465,9 +422,3 @@ func (a *ARM64) DwarfRegisterToString(i int, reg *op.DwarfRegister) (name string
 	}
 	return name, false, fmt.Sprintf("%#x", reg.Bytes)
 }
-
-// InhibitStepInto returns whether StepBreakpoint can be set at pc.
-// Always return false on arm64.
-func (a *ARM64) InhibitStepInto(bi *BinaryInfo, pc uint64) bool {
-	return false
-}

pkg/proc/arm64_disasm.go

@@ -8,9 +8,7 @@ import (
 	"golang.org/x/arch/arm64/arm64asm"
 )
 
-// AsmDecode decodes the assembly instruction starting at mem[0:] into asmInst.
-// It assumes that the Loc and AtPC fields of asmInst have already been filled.
-func (a *ARM64) AsmDecode(asmInst *AsmInstruction, mem []byte, regs Registers, memrw MemoryReadWriter, bi *BinaryInfo) error {
+func arm64AsmDecode(asmInst *AsmInstruction, mem []byte, regs Registers, memrw MemoryReadWriter, bi *BinaryInfo) error {
 	asmInst.Size = 4
 	asmInst.Bytes = mem[:asmInst.Size]
 
@@ -35,10 +33,6 @@ func (a *ARM64) AsmDecode(asmInst *AsmInstruction, mem []byte, regs Registers, m
 	return nil
 }
 
-func (a *ARM64) Prologues() []opcodeSeq {
-	return prologuesARM64
-}
-
 func resolveCallArgARM64(inst *arm64asm.Inst, instAddr uint64, currentGoroutine bool, regs Registers, mem MemoryReadWriter, bininfo *BinaryInfo) *Location {
 	if inst.Op != arm64asm.BL && inst.Op != arm64asm.BLR {
 		return nil

pkg/proc/bininfo.go

@@ -43,7 +43,7 @@ const (
 // includes both the executable and also any loaded libraries).
 type BinaryInfo struct {
 	// Architecture of this binary.
-	Arch Arch
+	Arch *Arch
 
 	// GOOS operating system this binary is executing on.
 	GOOS string

pkg/proc/core/core.go

@@ -313,11 +313,6 @@ func (t *Thread) RestoreRegisters(proc.Registers) error {
 	return ErrChangeRegisterCore
 }
 
-// Arch returns the architecture the target is built for and executing on.
-func (t *Thread) Arch() proc.Arch {
-	return t.p.bi.Arch
-}
-
 // BinInfo returns information about the binary.
 func (t *Thread) BinInfo() *proc.BinaryInfo {
 	return t.p.bi

pkg/proc/core/core_test.go

@@ -185,7 +185,7 @@ func withCoreFile(t *testing.T, name, args string) *proc.Target {
 	return p
 }
 
-func logRegisters(t *testing.T, regs proc.Registers, arch proc.Arch) {
+func logRegisters(t *testing.T, regs proc.Registers, arch *proc.Arch) {
 	dregs := arch.RegistersToDwarfRegisters(0, regs)
 	for i, reg := range dregs.Regs {
 		if reg == nil {

pkg/proc/disasm.go

@@ -139,7 +139,7 @@ func disassemble(memrw MemoryReadWriter, regs Registers, breakpoints *Breakpoint
 		inst.Breakpoint = atbp
 		inst.AtPC = (regs != nil) && (curpc == pc)
 
-		bi.Arch.AsmDecode(&inst, mem, regs, memrw, bi)
+		bi.Arch.asmDecode(&inst, mem, regs, memrw, bi)
 
 		r = append(r, inst)
 

pkg/proc/gdbserial/gdbserver.go

@@ -1303,11 +1303,6 @@ func (t *Thread) RestoreRegisters(savedRegs proc.Registers) error {
 	return t.writeRegisters()
 }
 
-// Arch will return the CPU architecture for the target.
-func (t *Thread) Arch() proc.Arch {
-	return t.p.bi.Arch
-}
-
 // BinInfo will return information on the binary being debugged.
 func (t *Thread) BinInfo() *proc.BinaryInfo {
 	return t.p.bi

pkg/proc/i386_arch.go

@@ -8,23 +8,6 @@ import (
 	"strings"
 )
 
-// I386 represents the Intel386 CPU architecture.
-type I386 struct {
-	gStructOffset uint64
-	goos          string
-
-	// crosscall2fn is the DIE of crosscall2, a function used by the go runtime
-	// to call C functions. This function in go 1.9 (and previous versions) had
-	// a bad frame descriptor which needs to be fixed to generate good stack
-	// traces.
-	crosscall2fn *Function
-
-	// sigreturnfn is the DIE of runtime.sigreturn, the return trampoline for
-	// the signal handler. See comment in FixFrameUnwindContext for a
-	// description of why this is needed.
-	sigreturnfn *Function
-}
-
 const (
 	i386DwarfIPRegNum uint64 = 8
 	i386DwarfSPRegNum uint64 = 4
@@ -35,50 +18,28 @@ var i386BreakInstruction = []byte{0xCC}
 
 // I386Arch returns an initialized I386Arch
 // struct.
-func I386Arch(goos string) *I386 {
-	return &I386{
-		goos: goos,
+func I386Arch(goos string) *Arch {
+	return &Arch{
+		Name:                             "386",
+		ptrSize:                          4,
+		maxInstructionLength:             15,
+		breakpointInstruction:            i386BreakInstruction,
+		breakInstrMovesPC:                true,
+		derefTLS:                         false,
+		prologues:                        prologuesI386,
+		fixFrameUnwindContext:            i386FixFrameUnwindContext,
+		switchStack:                      i386SwitchStack,
+		regSize:                          i386RegSize,
+		RegistersToDwarfRegisters:        i386RegistersToDwarfRegisters,
+		addrAndStackRegsToDwarfRegisters: i386AddrAndStackRegsToDwarfRegisters,
+		DwarfRegisterToString:            i386DwarfRegisterToString,
+		inhibitStepInto:                  i386InhibitStepInto,
+		asmDecode:                        i386AsmDecode,
 	}
 }
 
-// PtrSize returns the size of a pointer
-// on this architecture.
-func (i *I386) PtrSize() int {
-	return 4
-}
-
-// MaxInstructionLength returns the maximum length of an instruction.
-func (i *I386) MaxInstructionLength() int {
-	return 15
-}
-
-// BreakpointInstruction returns the Breakpoint
-// instruction for this architecture.
-func (i *I386) BreakpointInstruction() []byte {
-	return i386BreakInstruction
-}
-
-// BreakInstrMovesPC returns whether the
-// breakpoint instruction will change the value
-// of PC after being executed
-func (i *I386) BreakInstrMovesPC() bool {
-	return true
-}
-
-// BreakpointSize returns the size of the
-// breakpoint instruction on this architecture.
-func (i *I386) BreakpointSize() int {
-	return len(i386BreakInstruction)
-}
-
-// TODO, Not sure, always return false for now. Need to test on windows.
-func (i *I386) DerefTLS() bool {
-	return false
-}
-
-// FixFrameUnwindContext adds default architecture rules to fctxt or returns
-// the default frame unwind context if fctxt is nil.
-func (i *I386) FixFrameUnwindContext(fctxt *frame.FrameContext, pc uint64, bi *BinaryInfo) *frame.FrameContext {
+func i386FixFrameUnwindContext(fctxt *frame.FrameContext, pc uint64, bi *BinaryInfo) *frame.FrameContext {
+	i := bi.Arch
 	if i.sigreturnfn == nil {
 		i.sigreturnfn = bi.LookupFunc["runtime.sigreturn"]
 	}
@@ -153,9 +114,7 @@ func (i *I386) FixFrameUnwindContext(fctxt *frame.FrameContext, pc uint64, bi *B
 }
 
 // SwitchStack will use the current frame to determine if it's time to
-// switch between the system stack and the goroutine stack or vice versa.
-// Sets it.atend when the top of the stack is reached.
-func (i *I386) SwitchStack(it *stackIterator, _ *op.DwarfRegisters) bool {
+func i386SwitchStack(it *stackIterator, _ *op.DwarfRegisters) bool {
 	if it.frame.Current.Fn == nil {
 		return false
 	}
@@ -214,7 +173,7 @@ func (i *I386) SwitchStack(it *stackIterator, _ *op.DwarfRegisters) bool {
 // in the System V ABI Intel386 Architecture Processor Supplement page 25,
 // table 2.14
 // https://www.uclibc.org/docs/psABI-i386.pdf
-func (i *I386) RegSize(regnum uint64) int {
+func i386RegSize(regnum uint64) int {
 	// XMM registers
 	if regnum >= 21 && regnum <= 36 {
 		return 16
@@ -293,7 +252,7 @@ func maxI386DwarfRegister() int {
 	return max
 }
 
-func (i *I386) RegistersToDwarfRegisters(staticBase uint64, regs Registers) op.DwarfRegisters {
+func i386RegistersToDwarfRegisters(staticBase uint64, regs Registers) op.DwarfRegisters {
 	dregs := make([]*op.DwarfRegister, maxI386DwarfRegister()+1)
 
 	for _, reg := range regs.Slice(true) {
@@ -312,9 +271,7 @@ func (i *I386) RegistersToDwarfRegisters(staticBase uint64, regs Registers) op.D
 	}
 }
 
-// AddrAndStackRegsToDwarfRegisters returns DWARF registers from the passed in
-// PC, SP, and BP registers in the format used by the DWARF expression interpreter.
-func (i *I386) AddrAndStackRegsToDwarfRegisters(staticBase, pc, sp, bp, lr uint64) op.DwarfRegisters {
+func i386AddrAndStackRegsToDwarfRegisters(staticBase, pc, sp, bp, lr uint64) op.DwarfRegisters {
 	dregs := make([]*op.DwarfRegister, i386DwarfIPRegNum+1)
 	dregs[i386DwarfIPRegNum] = op.DwarfRegisterFromUint64(pc)
 	dregs[i386DwarfSPRegNum] = op.DwarfRegisterFromUint64(sp)
@@ -330,7 +287,7 @@ func (i *I386) AddrAndStackRegsToDwarfRegisters(staticBase, pc, sp, bp, lr uint6
 	}
 }
 
-func (i *I386) DwarfRegisterToString(j int, reg *op.DwarfRegister) (name string, floatingPoint bool, repr string) {
+func i386DwarfRegisterToString(j int, reg *op.DwarfRegister) (name string, floatingPoint bool, repr string) {
 	name, ok := i386DwarfToName[j]
 	if !ok {
 		name = fmt.Sprintf("unknown%d", j)
@@ -356,11 +313,11 @@ func (i *I386) DwarfRegisterToString(j int, reg *op.DwarfRegister) (name string,
 	}
 }
 
-// InhibitStepInto returns whether StepBreakpoint can be set at pc.
+// i386InhibitStepInto returns whether StepBreakpoint can be set at pc.
 // When cgo or pie on 386 linux, compiler will insert more instructions (ex: call __x86.get_pc_thunk.).
 // StepBreakpoint shouldn't be set on __x86.get_pc_thunk and skip it.
 // See comments on stacksplit in $GOROOT/src/cmd/internal/obj/x86/obj6.go for generated instructions details.
-func (i *I386) InhibitStepInto(bi *BinaryInfo, pc uint64) bool {
+func i386InhibitStepInto(bi *BinaryInfo, pc uint64) bool {
 	if bi.SymNames != nil && bi.SymNames[pc] != nil &&
 		strings.HasPrefix(bi.SymNames[pc].Name, "__x86.get_pc_thunk.") {
 		return true

pkg/proc/i386_disasm.go

@@ -8,18 +8,10 @@ import (
 	"golang.org/x/arch/x86/x86asm"
 )
 
-// AsmDecode decodes the assembly instruction starting at mem[0:] into asmInst.
-// It assumes that the Loc and AtPC fields of asmInst have already been filled.
-func (i *I386) AsmDecode(asmInst *AsmInstruction, mem []byte, regs Registers, memrw MemoryReadWriter, bi *BinaryInfo) error {
+func i386AsmDecode(asmInst *AsmInstruction, mem []byte, regs Registers, memrw MemoryReadWriter, bi *BinaryInfo) error {
 	return x86AsmDecode(asmInst, mem, regs, memrw, bi, 32)
 }
 
-// Prologues returns a list of stack split prologues
-// that are inserted at function entry.
-func (i *I386) Prologues() []opcodeSeq {
-	return prologuesI386
-}
-
 // Possible stacksplit prologues are inserted by stacksplit in
 // $GOROOT/src/cmd/internal/obj/x86/obj6.go.
 // If 386 on linux when pie, the stacksplit prologue beigin with `call __x86.get_pc_thunk.` sometime.

pkg/proc/native/threads.go

@@ -94,12 +94,6 @@ func (t *Thread) Location() (*proc.Location, error) {
 	return &proc.Location{PC: pc, File: f, Line: l, Fn: fn}, nil
 }
 
-// Arch returns the architecture the binary is
-// compiled for and executing on.
-func (t *Thread) Arch() proc.Arch {
-	return t.dbp.bi.Arch
-}
-
 // BinInfo returns information on the binary.
 func (t *Thread) BinInfo() *proc.BinaryInfo {
 	return t.dbp.bi
@@ -124,7 +118,7 @@ func (t *Thread) SetCurrentBreakpoint(adjustPC bool) error {
 	// of PC after being executed we should look for breakpoints
 	// with bp.Addr == PC and there is no need to call SetPC
 	// after finding one.
-	adjustPC = adjustPC && t.Arch().BreakInstrMovesPC()
+	adjustPC = adjustPC && t.BinInfo().Arch.BreakInstrMovesPC()
 
 	if bp, ok := t.dbp.FindBreakpoint(pc, adjustPC); ok {
 		if adjustPC {

pkg/proc/stack.go

@@ -127,7 +127,7 @@ func (g *G) stackIterator(opts StacktraceOptions) (*stackIterator, error) {
 	so := g.variable.bi.PCToImage(g.PC)
 	return newStackIterator(
 		bi, g.variable.mem,
-		bi.Arch.AddrAndStackRegsToDwarfRegisters(so.StaticBase, g.PC, g.SP, g.BP, g.LR),
+		bi.Arch.addrAndStackRegsToDwarfRegisters(so.StaticBase, g.PC, g.SP, g.BP, g.LR),
 		g.stackhi, stkbar, g.stkbarPos, g, opts), nil
 }
 
@@ -246,7 +246,7 @@ func (it *stackIterator) Next() bool {
 	}
 
 	if it.opts&StacktraceSimple == 0 {
-		if it.bi.Arch.SwitchStack(it, &callFrameRegs) {
+		if it.bi.Arch.switchStack(it, &callFrameRegs) {
 			return true
 		}
 	}
@@ -268,7 +268,7 @@ func (it *stackIterator) switchToGoroutineStack() {
 	it.pc = it.g.PC
 	it.regs.Reg(it.regs.SPRegNum).Uint64Val = it.g.SP
 	it.regs.AddReg(it.regs.BPRegNum, op.DwarfRegisterFromUint64(it.g.BP))
-	if _, ok := it.bi.Arch.(*ARM64); ok {
+	if it.bi.Arch.Name == "arm64" {
 		it.regs.Reg(it.regs.LRRegNum).Uint64Val = it.g.LR
 	}
 }
@@ -414,9 +414,9 @@ func (it *stackIterator) advanceRegs() (callFrameRegs op.DwarfRegisters, ret uin
 	fde, err := it.bi.frameEntries.FDEForPC(it.pc)
 	var framectx *frame.FrameContext
 	if _, nofde := err.(*frame.ErrNoFDEForPC); nofde {
-		framectx = it.bi.Arch.FixFrameUnwindContext(nil, it.pc, it.bi)
+		framectx = it.bi.Arch.fixFrameUnwindContext(nil, it.pc, it.bi)
 	} else {
-		framectx = it.bi.Arch.FixFrameUnwindContext(fde.EstablishFrame(it.pc), it.pc, it.bi)
+		framectx = it.bi.Arch.fixFrameUnwindContext(fde.EstablishFrame(it.pc), it.pc, it.bi)
 	}
 
 	cfareg, err := it.executeFrameRegRule(0, framectx.CFA, 0)
@@ -455,7 +455,7 @@ func (it *stackIterator) advanceRegs() (callFrameRegs op.DwarfRegisters, ret uin
 		}
 	}
 
-	if _, ok := it.bi.Arch.(*ARM64); ok {
+	if it.bi.Arch.Name == "arm64" {
 		if ret == 0 && it.regs.Regs[it.regs.LRRegNum] != nil {
 			ret = it.regs.Regs[it.regs.LRRegNum].Uint64Val
 		}
@@ -515,7 +515,7 @@ func (it *stackIterator) executeFrameRegRule(regnum uint64, rule frame.DWRule, c
 }
 
 func (it *stackIterator) readRegisterAt(regnum uint64, addr uint64) (*op.DwarfRegister, error) {
-	buf := make([]byte, it.bi.Arch.RegSize(regnum))
+	buf := make([]byte, it.bi.Arch.regSize(regnum))
 	_, err := it.mem.ReadMemory(buf, uintptr(addr))
 	if err != nil {
 		return nil, err

pkg/proc/target.go

@@ -152,8 +152,7 @@ func (t *Target) SupportsFunctionCalls() bool {
 	if ok, _ := t.Process.Recorded(); ok {
 		return false
 	}
-	_, ok := t.Process.BinInfo().Arch.(*AMD64)
-	return ok
+	return t.Process.BinInfo().Arch.Name == "amd64"
 }
 
 // ClearAllGCache clears the internal Goroutine cache.

pkg/proc/target_exec.go

@@ -770,7 +770,7 @@ func setStepIntoBreakpoint(dbp Process, text []AsmInstruction, cond ast.Expr) er
 	pc := instr.DestLoc.PC
 
 	// Skip InhibitStepInto functions for different arch.
-	if dbp.BinInfo().Arch.InhibitStepInto(dbp.BinInfo(), pc) {
+	if dbp.BinInfo().Arch.inhibitStepInto(dbp.BinInfo(), pc) {
 		return nil
 	}
 

pkg/proc/threads.go

@@ -23,7 +23,6 @@ type Thread interface {
 
 	// RestoreRegisters restores saved registers
 	RestoreRegisters(Registers) error
-	Arch() Arch
 	BinInfo() *BinaryInfo
 	StepInstruction() error
 	// Blocked returns true if the thread is blocked

pkg/proc/types.go

@@ -46,7 +46,7 @@ type runtimeTypeDIE struct {
 	kind   int64
 }
 
-func pointerTo(typ godwarf.Type, arch Arch) godwarf.Type {
+func pointerTo(typ godwarf.Type, arch *Arch) godwarf.Type {
 	return &godwarf.PtrType{
 		CommonType: godwarf.CommonType{
 			ByteSize:    int64(arch.PtrSize()),

pkg/proc/variables.go

@@ -432,7 +432,7 @@ func getGVariable(thread Thread) (*Variable, error) {
 		}
 	}
 
-	return newGVariable(thread, uintptr(gaddr), thread.Arch().DerefTLS())
+	return newGVariable(thread, uintptr(gaddr), thread.BinInfo().Arch.DerefTLS())
 }
 
 func newGVariable(thread Thread, gaddr uintptr, deref bool) (*Variable, error) {
@@ -446,7 +446,7 @@ func newGVariable(thread Thread, gaddr uintptr, deref bool) (*Variable, error) {
 	if deref {
 		typ = &godwarf.PtrType{
 			CommonType: godwarf.CommonType{
-				ByteSize:    int64(thread.Arch().PtrSize()),
+				ByteSize:    int64(thread.BinInfo().Arch.PtrSize()),
 				Name:        "",
 				ReflectKind: reflect.Ptr,
 				Offset:      0,
@@ -1305,7 +1305,7 @@ func convertToEface(srcv, dstv *Variable) error {
 	return dstv.writeEmptyInterface(typeAddr, srcv)
 }
 
-func readStringInfo(mem MemoryReadWriter, arch Arch, addr uintptr) (uintptr, int64, error) {
+func readStringInfo(mem MemoryReadWriter, arch *Arch, addr uintptr) (uintptr, int64, error) {
 	// string data structure is always two ptrs in size. Addr, followed by len
 	// http://research.swtch.com/godata
 

service/api/conversions.go

@@ -329,7 +329,7 @@ func LoadConfigFromProc(cfg *proc.LoadConfig) *LoadConfig {
 }
 
 // ConvertRegisters converts proc.Register to api.Register for a slice.
-func ConvertRegisters(in op.DwarfRegisters, arch proc.Arch, floatingPoint bool) (out []Register) {
+func ConvertRegisters(in op.DwarfRegisters, arch *proc.Arch, floatingPoint bool) (out []Register) {
 	out = make([]Register, 0, len(in.Regs))
 	for i := range in.Regs {
 		reg := in.Reg(uint64(i))