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[dev.cc] cmd/asm: rewrite to work with new obj API

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Considerable rewriting of the parser and assembler (code generator)
but it's simpler and shorter now. The internal Addr type is gone; so
is the package that held it. Parsing of operands goes directly into
obj.Addrs now.

There is a horrible hack regarding register pairs. It uses the Class
field to store the second register since it needs _some_ place to
put it but none is provided in the API. An alternative would be nice
but this works for now.

Once again creates identical .6 and .8 files as the old assembler.

Change-Id: I8207d6dfdfdb5bbed0bd870cb34ee0fe61c2fbfd
Reviewed-on: https://go-review.googlesource.com/4062
Reviewed-by: Russ Cox <rsc@golang.org>
This commit is contained in:
Rob Pike 2015-02-06 11:39:23 -08:00
parent 1fc330d8fe
commit cb19a20121
7 changed files with 332 additions and 614 deletions
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114
src/cmd/asm/internal/addr/addr.go
View File

@ -1,114 +0,0 @@
// +build ignore
// Copyright 2015 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 addr holds the definition of an instruction address.
package addr
// Addr represents a parsed address.
type Addr struct {
IsStatic bool // symbol<>
IsImmediateConstant bool // $3
IsImmediateAddress bool // $main·main(SB)
IsIndirect bool // (R1)
HasRegister bool // register is set
HasRegister2 bool // register2 is set
HasFloat bool // float is set
HasOffset bool // offset is set
HasString bool // string is set
Symbol string // "main·main"
Register int16 // R1
Register2 int16 // R1 in R0:R1
Offset int64 // 3
Float float64 // 1.0e2 (floating constant)
String string // "hi" (string constant)
Index int16 // R1 in (R1*8)
Scale int8 // 8 in (R1*8)
}
const (
// IsStatic does not appear here; Is and Has methods ignore it.
ImmediateConstant = 1 << iota
ImmediateAddress
Indirect
Symbol
Register
Register2
Offset
Float
String
Index
Scale
)
// Has reports whether the address has any of the specified elements.
// Indirect and immediate are not checked.
func (a *Addr) Has(mask int) bool {
if mask&Symbol != 0 && a.Symbol != "" {
return true
}
if mask&Register != 0 && a.HasRegister {
return true
}
if mask&Register2 != 0 && a.HasRegister2 {
return true
}
if mask&Offset != 0 && a.HasOffset {
return true
}
if mask&Float != 0 && a.HasFloat {
return true
}
if mask&String != 0 && a.HasString {
return true
}
if mask&Index != 0 && a.Index != 0 {
return true
}
if mask&Scale != 0 && a.Scale != 0 {
return true
}
return false
}
// Is reports whether the address has all the specified elements.
// Indirect and immediate are checked.
func (a *Addr) Is(mask int) bool {
if (mask&ImmediateConstant == 0) != !a.IsImmediateConstant {
return false
}
if (mask&ImmediateAddress == 0) != !a.IsImmediateAddress {
return false
}
if (mask&Indirect == 0) != !a.IsIndirect {
return false
}
if (mask&Symbol == 0) != (a.Symbol == "") {
return false
}
if (mask&Register == 0) != !a.HasRegister {
return false
}
if (mask&Register2 == 0) != !a.HasRegister2 {
return false
}
if (mask&Offset == 0) != !a.HasOffset {
// $0 has the immediate bit but value 0.
return false
}
if (mask&Float == 0) != !a.HasFloat {
return false
}
if (mask&String == 0) != !a.HasString {
return false
}
if (mask&Index == 0) != (a.Index == 0) {
return false
}
if (mask&Scale == 0) != (a.Scale == 0) {
return false
}
return true
}

62
src/cmd/asm/internal/arch/arch.go
View File

@ -1,5 +1,3 @@
// +build ignore
// Copyright 2015 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.
@ -23,22 +21,22 @@ const (
// Arch wraps the link architecture object with more architecture-specific information.
type Arch struct {
*obj.LinkArch
D_INDIR int // TODO: why not in LinkArch?
D_CONST2 int // TODO: why not in LinkArch?
// Register number of hardware stack pointer.
SP int
// Encoding of non-address.
NoAddr obj.Addr
// Map of instruction names to enumeration.
Instructions map[string]int
// Map of register names to enumeration.
Registers map[string]int
// Map of pseudo-instructions (TEXT, DATA etc.) to enumeration.
Pseudos map[string]int
Registers map[string]int16
// Instructions that take one operand whose result is a destination.
UnaryDestination map[int]bool
}
var Pseudos = map[string]int{
"DATA": obj.ADATA,
"FUNCDATA": obj.AFUNCDATA,
"GLOBL": obj.AGLOBL,
"PCDATA": obj.APCDATA,
"TEXT": obj.ATEXT,
}
// Set configures the architecture specified by GOARCH and returns its representation.
// It returns nil if GOARCH is not recognized.
func Set(GOARCH string) *Arch {
@ -53,21 +51,16 @@ func Set(GOARCH string) *Arch {
}
func arch386() *Arch {
noAddr := obj.Addr{
Type: i386.D_NONE,
Index: i386.D_NONE,
}
registers := make(map[string]int)
registers := make(map[string]int16)
// Create maps for easy lookup of instruction names etc.
// TODO: Should this be done in obj for us?
for i, s := range i386.Register {
registers[s] = i
registers[s] = int16(i + i386.REG_AL)
}
// Pseudo-registers.
registers["SB"] = RSB
registers["FP"] = RFP
registers["SP"] = RSP
registers["PC"] = RPC
instructions := make(map[string]int)
@ -108,13 +101,6 @@ func arch386() *Arch {
instructions["MOVOA"] = i386.AMOVO
instructions["MOVNTDQ"] = i386.AMOVNTO
pseudos := make(map[string]int) // TEXT, DATA etc.
pseudos["DATA"] = i386.ADATA
pseudos["FUNCDATA"] = i386.AFUNCDATA
pseudos["GLOBL"] = i386.AGLOBL
pseudos["PCDATA"] = i386.APCDATA
pseudos["TEXT"] = i386.ATEXT
unaryDestination := make(map[int]bool) // Instruction takes one operand and result is a destination.
// These instructions write to prog.To.
unaryDestination[i386.ABSWAPL] = true
@ -158,33 +144,23 @@ func arch386() *Arch {
return &Arch{
LinkArch: &i386.Link386,
D_INDIR: i386.D_INDIR,
D_CONST2: i386.D_CONST2,
SP: i386.D_SP,
NoAddr: noAddr,
Instructions: instructions,
Registers: registers,
Pseudos: pseudos,
UnaryDestination: unaryDestination,
}
}
func archAmd64() *Arch {
noAddr := obj.Addr{
Type: x86.D_NONE,
Index: x86.D_NONE,
}
registers := make(map[string]int)
registers := make(map[string]int16)
// Create maps for easy lookup of instruction names etc.
// TODO: Should this be done in obj for us?
for i, s := range x86.Register {
registers[s] = i
registers[s] = int16(i + x86.REG_AL)
}
// Pseudo-registers.
registers["SB"] = RSB
registers["FP"] = RFP
registers["SP"] = RSP
registers["PC"] = RPC
instructions := make(map[string]int)
@ -223,13 +199,6 @@ func archAmd64() *Arch {
instructions["MOVD"] = x86.AMOVQ
instructions["MOVDQ2Q"] = x86.AMOVQ
pseudos := make(map[string]int) // TEXT, DATA etc.
pseudos["DATA"] = x86.ADATA
pseudos["FUNCDATA"] = x86.AFUNCDATA
pseudos["GLOBL"] = x86.AGLOBL
pseudos["PCDATA"] = x86.APCDATA
pseudos["TEXT"] = x86.ATEXT
unaryDestination := make(map[int]bool) // Instruction takes one operand and result is a destination.
// These instructions write to prog.To.
unaryDestination[x86.ABSWAPL] = true
@ -282,13 +251,8 @@ func archAmd64() *Arch {
return &Arch{
LinkArch: &x86.Linkamd64,
D_INDIR: x86.D_INDIR,
D_CONST2: x86.D_NONE,
SP: x86.D_SP,
NoAddr: noAddr,
Instructions: instructions,
Registers: registers,
Pseudos: pseudos,
UnaryDestination: unaryDestination,
}
}

432
src/cmd/asm/internal/asm/asm.go
View File

@ -1,5 +1,3 @@
// +build ignore
// Copyright 2014 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.
@ -8,132 +6,18 @@ package asm
import (
"fmt"
"strings"
"text/scanner"
"cmd/asm/internal/addr"
"cmd/asm/internal/arch"
"cmd/asm/internal/flags"
"cmd/asm/internal/lex"
"cmd/internal/obj"
)
// TODO: This package has many numeric conversions that should be unnecessary.
// symbolType returns the extern/static etc. type appropriate for the symbol.
func (p *Parser) symbolType(a *addr.Addr) int {
switch a.Register {
case arch.RFP:
return p.arch.D_PARAM
case arch.RSP:
return p.arch.D_AUTO
case arch.RSB:
// See comment in addrToAddr.
if a.IsImmediateAddress {
return p.arch.D_ADDR
}
if a.IsStatic {
return p.arch.D_STATIC
}
return p.arch.D_EXTERN
}
p.errorf("invalid register for symbol %s", a.Symbol)
return 0
}
// staticVersion reports whether the data's Symbol has <>, as in data<>.
// It returns 1 for static, 0 for non-static, because that's what obj wants.
func staticVersion(a *addr.Addr) int {
if a.Symbol != "" && a.IsStatic {
return 1
}
return 0
}
// TODO: configure the architecture
// TODO: This is hacky and irregular. When obj settles down, rewrite for simplicity.
func (p *Parser) addrToAddr(a *addr.Addr) obj.Addr {
out := p.arch.NoAddr
if a.Has(addr.Symbol) {
// How to encode the symbols:
// syntax = Typ,Index
// $a(SB) = ADDR,EXTERN
// $a<>(SB) = ADDR,STATIC
// a(SB) = EXTERN,NONE
// a<>(SB) = STATIC,NONE
// The call to symbolType does the first column; we need to fix up Index here.
out.Type = int16(p.symbolType(a))
if a.IsImmediateAddress {
// Index field says whether it's a static.
switch a.Register {
case arch.RSB:
if a.IsStatic {
out.Index = uint8(p.arch.D_STATIC)
} else {
out.Index = uint8(p.arch.D_EXTERN)
}
default:
p.errorf("can't handle immediate address of %s not (SB)\n", a.Symbol)
}
}
out.Sym = obj.Linklookup(p.linkCtxt, a.Symbol, staticVersion(a))
} else if a.Has(addr.Register) {
// TODO: SP is tricky, and this isn't good enough.
// SP = D_SP
// 4(SP) = 4(D_SP)
// x+4(SP) = D_AUTO with sym=x TODO
out.Type = a.Register
if a.Register == arch.RSP {
out.Type = int16(p.arch.SP)
}
if a.IsIndirect {
out.Type += int16(p.arch.D_INDIR)
}
// a.Register2 handled in the instruction method; it's bizarre.
}
if a.Has(addr.Index) {
out.Index = uint8(a.Index) // TODO: out.Index == p.NoArch.Index should be same type as Register.
}
if a.Has(addr.Scale) {
out.Scale = a.Scale
}
if a.Has(addr.Offset) {
out.Offset = a.Offset
if a.Is(addr.Offset) {
// RHS of MOVL $0xf1, 0xf1 // crash
out.Type = int16(p.arch.D_INDIR + p.arch.D_NONE)
} else if a.IsImmediateConstant && out.Type == int16(p.arch.D_NONE) {
out.Type = int16(p.arch.D_CONST)
}
}
if a.Has(addr.Float) {
out.U.Dval = a.Float
out.Type = int16(p.arch.D_FCONST)
}
if a.Has(addr.String) {
out.U.Sval = a.String
out.Type = int16(p.arch.D_SCONST)
}
// TODO from https://go-review.googlesource.com/#/c/3196/ {
// There's a general rule underlying this special case and the one at line 91 (RHS OF MOVL $0xf1).
// Unless there's a $, it's an indirect.
// 4(R1)(R2*8)
// 4(R1)
// 4(R2*8)
// 4
// (R1)(R2*8)
// (R1)
// (R2*8)
// There should be a more general approach that doesn't just pick off cases.
// }
if a.IsIndirect && !a.Has(addr.Register) && a.Has(addr.Index) {
// LHS of LEAQ 0(BX*8), CX
out.Type = int16(p.arch.D_INDIR + p.arch.D_NONE)
}
return out
}
// append adds the Prog to the end of the program-thus-far.
// If doLabel is set, it also defines the labels collect for this Prog.
func (p *Parser) append(prog *obj.Prog, doLabel bool) {
if p.firstProg == nil {
p.firstProg = prog
@ -157,6 +41,23 @@ func (p *Parser) append(prog *obj.Prog, doLabel bool) {
}
}
func (p *Parser) validatePseudoSymbol(pseudo string, addr *obj.Addr, offsetOk bool) {
if addr.Name != obj.NAME_EXTERN && addr.Name != obj.NAME_STATIC || addr.Scale != 0 || addr.Reg != 0 {
p.errorf("%s symbol %q must be a symbol(SB)", pseudo, addr.Sym.Name)
}
if !offsetOk && addr.Offset != 0 {
p.errorf("%s symbol %q must not be offset from SB", pseudo, addr.Sym.Name)
}
}
func (p *Parser) evalInteger(pseudo string, operands []lex.Token) int64 {
addr := p.address(operands)
if addr.Type != obj.TYPE_MEM || addr.Name != 0 || addr.Reg != 0 || addr.Index != 0 {
p.errorf("%s: text flag must be an integer constant")
}
return addr.Offset
}
// asmText assembles a TEXT pseudo-op.
// TEXT runtime·sigtramp(SB),4,$0-0
func (p *Parser) asmText(word string, operands [][]lex.Token) {
@ -172,20 +73,14 @@ func (p *Parser) asmText(word string, operands [][]lex.Token) {
// Operand 0 is the symbol name in the form foo(SB).
// That means symbol plus indirect on SB and no offset.
nameAddr := p.address(operands[0])
if !nameAddr.Is(addr.Symbol|addr.Register|addr.Indirect) || nameAddr.Register != arch.RSB {
p.errorf("TEXT symbol %q must be an offset from SB", nameAddr.Symbol)
}
name := nameAddr.Symbol
p.validatePseudoSymbol("TEXT", &nameAddr, false)
name := nameAddr.Sym.Name
next := 1
// Next operand is the optional text flag, a literal integer.
flag := int8(0)
var flag = int64(0)
if len(operands) == 3 {
flagAddr := p.address(operands[next])
if !flagAddr.Is(addr.Offset) {
p.errorf("TEXT flag for %s must be an integer", name)
}
flag = int8(flagAddr.Offset)
flag = p.evalInteger("TEXT", operands[1])
next++
}
@ -223,31 +118,19 @@ func (p *Parser) asmText(word string, operands [][]lex.Token) {
}
prog := &obj.Prog{
Ctxt: p.linkCtxt,
As: int16(p.arch.ATEXT),
Lineno: int32(p.histLineNum),
From: obj.Addr{
Type: int16(p.symbolType(&nameAddr)),
Index: uint8(p.arch.D_NONE),
Sym: obj.Linklookup(p.linkCtxt, name, staticVersion(&nameAddr)),
Scale: flag,
As: obj.ATEXT,
Lineno: p.histLineNum,
From: nameAddr,
From3: obj.Addr{
Offset: flag,
},
To: obj.Addr{
Index: uint8(p.arch.D_NONE),
Type: obj.TYPE_TEXTSIZE,
Offset: frameSize,
// Argsize set below.
},
}
// Encoding of frameSize and argSize depends on architecture.
switch p.arch.Thechar {
case '6':
prog.To.Type = int16(p.arch.D_CONST)
prog.To.Offset = (argSize << 32) | frameSize
case '8':
prog.To.Type = int16(p.arch.D_CONST2)
prog.To.Offset = frameSize
prog.To.Offset2 = int32(argSize)
default:
p.errorf("internal error: can't encode TEXT $arg-frame")
}
prog.To.U.Argsize = int32(argSize)
p.append(prog, true)
}
@ -265,39 +148,36 @@ func (p *Parser) asmData(word string, operands [][]lex.Token) {
if n < 3 || op[n-2].ScanToken != '/' || op[n-1].ScanToken != scanner.Int {
p.errorf("expect /size for DATA argument")
}
scale := p.scale(op[n-1].String())
scale := p.parseScale(op[n-1].String())
op = op[:n-2]
nameAddr := p.address(op)
ok := nameAddr.Is(addr.Symbol|addr.Register|addr.Indirect) || nameAddr.Is(addr.Symbol|addr.Register|addr.Indirect|addr.Offset)
if !ok || nameAddr.Register != arch.RSB {
p.errorf("DATA symbol %q must be an offset from SB", nameAddr.Symbol)
}
name := strings.Replace(nameAddr.Symbol, "·", ".", 1)
p.validatePseudoSymbol("DATA", &nameAddr, true)
name := nameAddr.Sym.Name
// Operand 1 is an immediate constant or address.
valueAddr := p.address(operands[1])
if !valueAddr.IsImmediateConstant && !valueAddr.IsImmediateAddress {
switch valueAddr.Type {
case obj.TYPE_CONST, obj.TYPE_FCONST, obj.TYPE_SCONST, obj.TYPE_ADDR:
// OK
default:
p.errorf("DATA value must be an immediate constant or address")
}
// The addresses must not overlap. Easiest test: require monotonicity.
if lastAddr, ok := p.dataAddr[name]; ok && nameAddr.Offset < lastAddr {
p.errorf("overlapping DATA entry for %s", nameAddr.Symbol)
p.errorf("overlapping DATA entry for %s", name)
}
p.dataAddr[name] = nameAddr.Offset + int64(scale)
prog := &obj.Prog{
Ctxt: p.linkCtxt,
As: int16(p.arch.ADATA),
Lineno: int32(p.histLineNum),
From: obj.Addr{
Type: int16(p.symbolType(&nameAddr)),
Index: uint8(p.arch.D_NONE),
Sym: obj.Linklookup(p.linkCtxt, name, staticVersion(&nameAddr)),
Offset: nameAddr.Offset,
Scale: scale,
As: obj.ADATA,
Lineno: p.histLineNum,
From: nameAddr,
From3: obj.Addr{
Offset: int64(scale),
},
To: p.addrToAddr(&valueAddr),
To: valueAddr,
}
p.append(prog, false)
@ -313,46 +193,36 @@ func (p *Parser) asmGlobl(word string, operands [][]lex.Token) {
// Operand 0 has the general form foo<>+0x04(SB).
nameAddr := p.address(operands[0])
ok := nameAddr.Is(addr.Symbol|addr.Register|addr.Indirect) || nameAddr.Is(addr.Symbol|addr.Register|addr.Indirect|addr.Offset)
if !ok || nameAddr.Register != arch.RSB {
p.errorf("GLOBL symbol %q must be an offset from SB", nameAddr.Symbol)
}
name := strings.Replace(nameAddr.Symbol, "·", ".", 1)
p.validatePseudoSymbol("GLOBL", &nameAddr, false)
name := nameAddr.Sym.Name
next := 1
// If three operands, middle operand is a scale.
scale := int8(0)
op := operands[1]
// Next operand is the optional flag, a literal integer.
var flag = int64(0)
if len(operands) == 3 {
scaleAddr := p.address(op)
if !scaleAddr.Is(addr.Offset) {
p.errorf("GLOBL scale must be a constant")
}
scale = int8(scaleAddr.Offset)
op = operands[2]
flag = p.evalInteger("GLOBL", operands[1])
next++
}
// Final operand is an immediate constant.
sizeAddr := p.address(op)
if !sizeAddr.Is(addr.ImmediateConstant | addr.Offset) {
p.errorf("GLOBL size must be an immediate constant")
op := operands[next]
if len(op) < 2 || op[0].ScanToken != '$' || op[1].ScanToken != scanner.Int {
p.errorf("GLOBL %s: size must be an immediate constant", name)
}
size := sizeAddr.Offset
size := p.positiveAtoi(op[1].String())
// log.Printf("GLOBL %s %d, $%d", name, scale, size)
// log.Printf("GLOBL %s %d, $%d", name, flag, size)
prog := &obj.Prog{
Ctxt: p.linkCtxt,
As: int16(p.arch.AGLOBL),
Lineno: int32(p.histLineNum),
From: obj.Addr{
Type: int16(p.symbolType(&nameAddr)),
Index: uint8(p.arch.D_NONE),
Sym: obj.Linklookup(p.linkCtxt, name, staticVersion(&nameAddr)),
Offset: nameAddr.Offset,
Scale: scale,
As: obj.AGLOBL,
Lineno: p.histLineNum,
From: nameAddr,
From3: obj.Addr{
Offset: flag,
},
To: obj.Addr{
Type: int16(p.arch.D_CONST),
Index: uint8(p.arch.D_NONE),
Type: obj.TYPE_CONST,
Index: 0,
Offset: size,
},
}
@ -367,34 +237,24 @@ func (p *Parser) asmPCData(word string, operands [][]lex.Token) {
}
// Operand 0 must be an immediate constant.
addr0 := p.address(operands[0])
if !addr0.Is(addr.ImmediateConstant | addr.Offset) {
p.errorf("PCDATA value must be an immediate constant")
key := p.address(operands[0])
if key.Type != obj.TYPE_CONST {
p.errorf("PCDATA key must be an immediate constant")
}
value0 := addr0.Offset
// Operand 1 must be an immediate constant.
addr1 := p.address(operands[1])
if !addr1.Is(addr.ImmediateConstant | addr.Offset) {
value := p.address(operands[1])
if value.Type != obj.TYPE_CONST {
p.errorf("PCDATA value must be an immediate constant")
}
value1 := addr1.Offset
// log.Printf("PCDATA $%d, $%d", value0, value1)
// log.Printf("PCDATA $%d, $%d", key.Offset, value.Offset)
prog := &obj.Prog{
Ctxt: p.linkCtxt,
As: int16(p.arch.APCDATA),
Lineno: int32(p.histLineNum),
From: obj.Addr{
Type: int16(p.arch.D_CONST),
Index: uint8(p.arch.D_NONE),
Offset: value0,
},
To: obj.Addr{
Type: int16(p.arch.D_CONST),
Index: uint8(p.arch.D_NONE),
Offset: value1,
},
As: obj.APCDATA,
Lineno: p.histLineNum,
From: key,
To: value,
}
p.append(prog, true)
}
@ -408,37 +268,20 @@ func (p *Parser) asmFuncData(word string, operands [][]lex.Token) {
// Operand 0 must be an immediate constant.
valueAddr := p.address(operands[0])
if !valueAddr.Is(addr.ImmediateConstant | addr.Offset) {
p.errorf("FUNCDATA value must be an immediate constant")
if valueAddr.Type != obj.TYPE_CONST {
p.errorf("FUNCDATA value0 must be an immediate constant")
}
value0 := valueAddr.Offset
// Operand 1 is a symbol name in the form foo(SB).
// That means symbol plus indirect on SB and no offset.
nameAddr := p.address(operands[1])
ok := nameAddr.Is(addr.Symbol|addr.Register|addr.Indirect) || nameAddr.Is(addr.Symbol|addr.Register|addr.Indirect|addr.Offset)
if !ok || nameAddr.Register != arch.RSB {
p.errorf("FUNCDATA symbol %q must be an offset from SB", nameAddr.Symbol)
}
name := strings.Replace(nameAddr.Symbol, "·", ".", 1)
value1 := nameAddr.Offset
p.validatePseudoSymbol("FUNCDATA", &nameAddr, true)
// log.Printf("FUNCDATA $%d, %d", value0, value1)
prog := &obj.Prog{
Ctxt: p.linkCtxt,
As: int16(p.arch.AFUNCDATA),
Lineno: int32(p.histLineNum),
From: obj.Addr{
Type: int16(p.arch.D_CONST),
Index: uint8(p.arch.D_NONE),
Offset: value0,
},
To: obj.Addr{
Type: int16(p.symbolType(&nameAddr)),
Index: uint8(p.arch.D_NONE),
Sym: obj.Linklookup(p.linkCtxt, name, staticVersion(&nameAddr)),
Offset: value1,
},
As: obj.AFUNCDATA,
Lineno: p.histLineNum,
From: valueAddr,
To: nameAddr,
}
p.append(prog, true)
}
@ -447,58 +290,52 @@ func (p *Parser) asmFuncData(word string, operands [][]lex.Token) {
// JMP R1
// JMP exit
// JMP 3(PC)
func (p *Parser) asmJump(op int, a []addr.Addr) {
var target *addr.Addr
func (p *Parser) asmJump(op int, a []obj.Addr) {
var target *obj.Addr
switch len(a) {
default:
p.errorf("jump must have one or two addresses")
case 1:
target = &a[0]
case 2:
if !a[0].Is(0) {
p.errorf("two-address jump must have empty first address")
}
target = &a[1]
default:
p.errorf("wrong number of arguments to jump instruction")
}
prog := &obj.Prog{
Ctxt: p.linkCtxt,
Lineno: int32(p.histLineNum),
Lineno: p.histLineNum,
As: int16(op),
From: p.arch.NoAddr,
}
switch {
case target.Is(addr.Register):
case target.Type == obj.TYPE_REG:
// JMP R1
prog.To = p.addrToAddr(target)
case target.Is(addr.Symbol):
prog.To = *target
case target.Type == obj.TYPE_MEM && (target.Name == obj.NAME_EXTERN || target.Name == obj.NAME_STATIC):
// JMP main·morestack(SB)
isStatic := 0
if target.Name == obj.NAME_STATIC {
isStatic = 1
}
prog.To = obj.Addr{
Type: obj.TYPE_BRANCH,
Sym: obj.Linklookup(p.linkCtxt, target.Sym.Name, isStatic),
Index: 0,
Offset: target.Offset,
}
case target.Type == obj.TYPE_MEM && target.Reg == 0 && target.Offset == 0:
// JMP exit
targetProg := p.labels[target.Symbol]
targetProg := p.labels[target.Sym.Name]
if targetProg == nil {
p.toPatch = append(p.toPatch, Patch{prog, target.Symbol})
p.toPatch = append(p.toPatch, Patch{prog, target.Sym.Name})
} else {
p.branch(prog, targetProg)
}
case target.Is(addr.Register | addr.Indirect), target.Is(addr.Register | addr.Indirect | addr.Offset):
// JMP 4(AX)
if target.Register == arch.RPC {
case target.Type == obj.TYPE_MEM && target.Name == obj.NAME_NONE:
// JMP 4(PC)
if target.Reg == arch.RPC {
prog.To = obj.Addr{
Type: int16(p.arch.D_BRANCH),
Index: uint8(p.arch.D_NONE),
Type: obj.TYPE_BRANCH,
Offset: p.pc + 1 + target.Offset, // +1 because p.pc is incremented in link, below.
}
} else {
prog.To = p.addrToAddr(target)
}
case target.Is(addr.Symbol | addr.Indirect | addr.Register):
// JMP main·morestack(SB)
if target.Register != arch.RSB {
p.errorf("jmp to symbol must be SB-relative")
}
prog.To = obj.Addr{
Type: int16(p.arch.D_BRANCH),
Sym: obj.Linklookup(p.linkCtxt, target.Symbol, staticVersion(target)),
Index: uint8(p.arch.D_NONE),
Offset: target.Offset,
prog.To = *target
}
default:
p.errorf("cannot assemble jump %+v", target)
@ -520,62 +357,63 @@ func (p *Parser) patch() {
func (p *Parser) branch(jmp, target *obj.Prog) {
jmp.To = obj.Addr{
Type: int16(p.arch.D_BRANCH),
Index: uint8(p.arch.D_NONE),
Type: obj.TYPE_BRANCH,
Index: 0,
}
jmp.To.U.Branch = target
}
// asmInstruction assembles an instruction.
// MOVW R9, (R10)
func (p *Parser) asmInstruction(op int, a []addr.Addr) {
func (p *Parser) asmInstruction(op int, a []obj.Addr) {
prog := &obj.Prog{
Ctxt: p.linkCtxt,
Lineno: int32(p.histLineNum),
Lineno: p.histLineNum,
As: int16(op),
}
switch len(a) {
case 0:
prog.From = p.arch.NoAddr
prog.To = p.arch.NoAddr
// Nothing to do.
case 1:
if p.arch.UnaryDestination[op] {
prog.From = p.arch.NoAddr
prog.To = p.addrToAddr(&a[0])
// prog.From is no address.
prog.To = a[0]
} else {
prog.From = p.addrToAddr(&a[0])
prog.To = p.arch.NoAddr
prog.From = a[0]
// prog.To is no address.
}
case 2:
prog.From = p.addrToAddr(&a[0])
prog.To = p.addrToAddr(&a[1])
prog.From = a[0]
prog.To = a[1]
// DX:AX as a register pair can only appear on the RHS.
// Bizarrely, to obj it's specified by setting index on the LHS.
// TODO: can we fix this?
if a[1].Has(addr.Register2) {
if int(prog.From.Index) != p.arch.D_NONE {
p.errorf("register pair operand on RHS must have register on LHS")
if a[1].Class != 0 {
if a[0].Class != 0 {
p.errorf("register pair must be on LHS")
}
prog.From.Index = uint8(a[1].Register2)
prog.From.Index = int16(a[1].Class)
prog.To.Class = 0
}
case 3:
// CMPSD etc.; third operand is imm8, stored in offset, or a register.
prog.From = p.addrToAddr(&a[0])
prog.To = p.addrToAddr(&a[1])
switch {
case a[2].Is(addr.Offset):
prog.From = a[0]
prog.To = a[1]
switch a[2].Type {
case obj.TYPE_MEM:
prog.To.Offset = a[2].Offset
case a[2].Is(addr.Register):
case obj.TYPE_REG:
// Strange reodering.
prog.To = p.addrToAddr(&a[2])
prog.From = p.addrToAddr(&a[1])
if !a[0].IsImmediateConstant {
p.errorf("expected $value for 1st operand")
prog.To = a[2]
prog.From = a[1]
if a[0].Type != obj.TYPE_CONST {
p.errorf("expected immediate constant for 1st operand")
}
prog.To.Offset = a[0].Offset
default:
p.errorf("expected offset or register for 3rd operand")
}
default:
p.errorf("can't handle instruction with %d operands", len(a))
}

340
src/cmd/asm/internal/asm/parse.go
View File

@ -1,5 +1,3 @@
// +build ignore
// Copyright 2015 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.
@ -15,7 +13,6 @@ import (
"strconv"
"text/scanner"
"cmd/asm/internal/addr"
"cmd/asm/internal/arch"
"cmd/asm/internal/lex"
"cmd/internal/obj"
@ -24,8 +21,8 @@ import (
type Parser struct {
lex lex.TokenReader
lineNum int // Line number in source file.
histLineNum int // Cumulative line number across source files.
errorLine int // (Cumulative) line number of last error.
histLineNum int32 // Cumulative line number across source files.
errorLine int32 // (Cumulative) line number of last error.
errorCount int // Number of errors.
pc int64 // virtual PC; count of Progs; doesn't advance for GLOBL or DATA.
input []lex.Token
@ -33,7 +30,7 @@ type Parser struct {
pendingLabels []string // Labels to attach to next instruction.
labels map[string]*obj.Prog
toPatch []Patch
addr []addr.Addr
addr []obj.Addr
arch *arch.Arch
linkCtxt *obj.Link
firstProg *obj.Prog
@ -134,7 +131,7 @@ func (p *Parser) line() bool {
p.errorf("missing operand")
}
}
i := p.arch.Pseudos[word]
i := arch.Pseudos[word]
if i != 0 {
p.pseudo(i, word, operands)
return true
@ -150,11 +147,15 @@ func (p *Parser) line() bool {
func (p *Parser) instruction(op int, word string, operands [][]lex.Token) {
p.addr = p.addr[0:0]
isJump := word[0] == 'J' || word == "CALL" // TODO: do this better
for _, op := range operands {
p.addr = append(p.addr, p.address(op))
addr := p.address(op)
if !isJump && addr.Reg < 0 { // Jumps refer to PC, a pseudo.
p.errorf("illegal use of pseudo-register")
}
// Is it a jump? TODO
if word[0] == 'J' || word == "CALL" {
p.addr = append(p.addr, addr)
}
if isJump {
p.asmJump(op, p.addr)
return
}
@ -163,15 +164,15 @@ func (p *Parser) instruction(op int, word string, operands [][]lex.Token) {
func (p *Parser) pseudo(op int, word string, operands [][]lex.Token) {
switch op {
case p.arch.ATEXT:
case obj.ATEXT:
p.asmText(word, operands)
case p.arch.ADATA:
case obj.ADATA:
p.asmData(word, operands)
case p.arch.AGLOBL:
case obj.AGLOBL:
p.asmGlobl(word, operands)
case p.arch.APCDATA:
case obj.APCDATA:
p.asmPCData(word, operands)
case p.arch.AFUNCDATA:
case obj.AFUNCDATA:
p.asmFuncData(word, operands)
default:
p.errorf("unimplemented: %s", word)
@ -184,47 +185,15 @@ func (p *Parser) start(operand []lex.Token) {
}
// address parses the operand into a link address structure.
func (p *Parser) address(operand []lex.Token) addr.Addr {
func (p *Parser) address(operand []lex.Token) obj.Addr {
p.start(operand)
addr := addr.Addr{}
addr := obj.Addr{}
p.operand(&addr)
return addr
}
// parse (R). The opening paren is known to be there.
// The return value states whether it was a scaled mode.
func (p *Parser) parenRegister(a *addr.Addr) bool {
p.next()
tok := p.next()
if tok.ScanToken != scanner.Ident {
p.errorf("expected register, got %s", tok)
}
r, present := p.arch.Registers[tok.String()]
if !present {
p.errorf("expected register, found %s", tok.String())
}
a.IsIndirect = true
scaled := p.peek() == '*'
if scaled {
// (R*2)
p.next()
tok := p.get(scanner.Int)
a.Scale = p.scale(tok.String())
a.Index = int16(r) // TODO: r should have type int16 but is uint8.
} else {
if a.HasRegister {
p.errorf("multiple indirections")
}
a.HasRegister = true
a.Register = int16(r)
}
p.expect(')')
p.next()
return scaled
}
// scale converts a decimal string into a valid scale factor.
func (p *Parser) scale(s string) int8 {
// parseScale converts a decimal string into a valid scale factor.
func (p *Parser) parseScale(s string) int8 {
switch s {
case "1", "2", "4", "8":
return int8(s[0] - '0')
@ -233,120 +202,189 @@ func (p *Parser) scale(s string) int8 {
return 0
}
// parse (R) or (R)(R*scale). The opening paren is known to be there.
func (p *Parser) addressMode(a *addr.Addr) {
scaled := p.parenRegister(a)
if !scaled && p.peek() == '(' {
p.parenRegister(a)
}
}
// operand parses a general operand and stores the result in *a.
func (p *Parser) operand(a *addr.Addr) bool {
func (p *Parser) operand(a *obj.Addr) bool {
if len(p.input) == 0 {
p.errorf("empty operand: cannot happen")
return false
}
// General address (with a few exceptions) looks like
// $sym±offset(symkind)(reg)(index*scale)
// Every piece is optional, so we scan left to right and what
// we discover tells us where we are.
var prefix rune
switch tok := p.peek(); tok {
case '$', '*':
prefix = rune(tok)
p.next()
}
switch p.peek() {
case scanner.Ident:
tok := p.next()
if r1, r2, scale, ok := p.register(tok.String(), prefix); ok {
if scale != 0 {
p.errorf("expected simple register reference")
}
a.Type = obj.TYPE_REG
a.Reg = r1
if r2 != 0 {
// Form is R1:R2. It is on RHS and the second register
// needs to go into the LHS. This is a horrible hack. TODO.
a.Class = int8(r2)
}
break // Nothing can follow.
}
p.symbolReference(a, tok.String(), prefix)
case scanner.Int, scanner.Float, scanner.String, '+', '-', '~', '(':
if p.have(scanner.Float) {
if prefix != '$' {
p.errorf("floating-point constant must be an immediate")
}
a.Type = obj.TYPE_FCONST
a.U.Dval = p.floatExpr()
break
}
if p.have(scanner.String) {
if prefix != '$' {
p.errorf("string constant must be an immediate")
}
str, err := strconv.Unquote(p.get(scanner.String).String())
if err != nil {
p.errorf("string parse error: %s", err)
}
a.Type = obj.TYPE_SCONST
a.U.Sval = str
break
}
// Might be parenthesized arithmetic expression or (possibly scaled) register indirect.
// Peek into the input to discriminate.
if p.peek() == '(' && len(p.input[p.inputPos:]) >= 3 && p.input[p.inputPos+1].ScanToken == scanner.Ident {
// Register indirect (the identifier must be a register). The offset will be zero.
} else {
// Integer offset before register.
a.Offset = int64(p.expr())
}
if p.peek() != '(' {
// Just an integer.
switch prefix {
case '$':
p.next()
switch p.peek() {
case scanner.Ident:
a.IsImmediateAddress = true
p.operand(a) // TODO
case scanner.String:
a.IsImmediateConstant = true
a.HasString = true
a.String = p.atos(p.next().String())
case scanner.Int, scanner.Float, '+', '-', '~', '(':
a.IsImmediateConstant = true
if p.have(scanner.Float) {
a.HasFloat = true
a.Float = p.floatExpr()
} else {
a.HasOffset = true
a.Offset = int64(p.expr())
}
default:
p.errorf("illegal %s in immediate operand", p.next().String())
}
a.Type = obj.TYPE_CONST
case '*':
p.next()
tok := p.next()
r, present := p.arch.Registers[tok.String()]
if !present {
p.errorf("expected register; got %s", tok.String())
}
a.HasRegister = true
a.Register = int16(r)
case '(':
p.next()
if p.peek() == scanner.Ident {
p.back()
p.addressMode(a)
break
}
p.back()
fallthrough
case '+', '-', '~', scanner.Int, scanner.Float:
if p.have(scanner.Float) {
a.HasFloat = true
a.Float = p.floatExpr()
} else {
a.HasOffset = true
a.Offset = int64(p.expr())
}
if p.peek() != scanner.EOF {
p.expect('(')
p.addressMode(a)
}
case scanner.Ident:
tok := p.next()
// Either R or (most general) ident<>+4(SB)(R*scale).
if r, present := p.arch.Registers[tok.String()]; present {
a.HasRegister = true
a.Register = int16(r)
// Possibly register pair: DX:AX.
if p.peek() == ':' {
p.next()
tok = p.get(scanner.Ident)
a.HasRegister2 = true
a.Register2 = int16(p.arch.Registers[tok.String()])
}
break
}
// Weirdness with statics: Might now have "<>".
if p.peek() == '<' {
p.next()
p.get('>')
a.IsStatic = true
}
if p.peek() == '+' || p.peek() == '-' {
a.HasOffset = true
a.Offset = int64(p.expr())
}
a.Symbol = tok.String()
if p.peek() == scanner.EOF {
break
}
// Expect (SB) or (FP)
p.expect('(')
p.parenRegister(a)
if a.Register != arch.RSB && a.Register != arch.RFP && a.Register != arch.RSP {
p.errorf("expected SB, FP, or SP offset for %s", tok)
}
// Possibly have scaled register (CX*8).
if p.peek() != scanner.EOF {
p.expect('(')
p.addressMode(a)
}
a.Type = obj.TYPE_INDIR // Can appear but is illegal, will be rejected by the linker.
default:
p.errorf("unexpected %s in operand", p.next())
a.Type = obj.TYPE_MEM
}
break // Nothing can follow.
}
p.next()
tok := p.next()
r1, r2, scale, ok := p.register(tok.String(), 0)
if !ok {
p.errorf("indirect through non-register %s", tok)
}
if r2 != 0 {
p.errorf("indirect through register pair")
}
a.Type = obj.TYPE_MEM
if prefix == '$' {
a.Type = obj.TYPE_ADDR
}
a.Reg = r1
a.Scale = scale
p.get(')')
if scale == 0 && p.peek() == '(' {
p.next()
tok := p.next()
r1, r2, scale, ok = p.register(tok.String(), 0)
if !ok {
p.errorf("indirect through non-register %s", tok)
}
if r2 != 0 {
p.errorf("unimplemented two-register form")
}
a.Index = r1
a.Scale = scale
p.get(')')
}
}
p.expect(scanner.EOF)
return true
}
// register parses a register reference where there is no symbol present (as in 4(R0) not sym(SB)).
func (p *Parser) register(name string, prefix rune) (r1, r2 int16, scale int8, ok bool) {
// R1 or R1:R2 or R1*scale.
var present bool
r1, present = p.arch.Registers[name]
if !present {
return
}
if prefix != 0 {
p.errorf("prefix %c not allowed for register: $%s", prefix, name)
}
if p.peek() == ':' {
// 2nd register.
p.next()
name := p.next().String()
r2, present = p.arch.Registers[name]
if !present {
p.errorf("%s not a register", name)
}
}
if p.peek() == '*' {
// Scale
p.next()
scale = p.parseScale(p.next().String())
}
// TODO: Shifted register for ARM
return r1, r2, scale, true
}
// symbolReference parses a symbol that is known not to be a register.
func (p *Parser) symbolReference(a *obj.Addr, name string, prefix rune) {
// Identifier is a name.
switch prefix {
case 0:
a.Type = obj.TYPE_MEM
case '$':
a.Type = obj.TYPE_ADDR
case '*':
a.Type = obj.TYPE_INDIR
}
// Weirdness with statics: Might now have "<>".
isStatic := 0 // TODO: Really a boolean, but Linklookup wants a "version" integer.
if p.peek() == '<' {
isStatic = 1
p.next()
p.get('>')
}
if p.peek() == '+' || p.peek() == '-' {
a.Offset = int64(p.expr())
}
a.Sym = obj.Linklookup(p.linkCtxt, name, isStatic)
if p.peek() == scanner.EOF {
return
}
// Expect (SB) or (FP) or (SP).
p.get('(')
reg := p.get(scanner.Ident).String()
switch reg {
case "FP":
a.Name = obj.NAME_PARAM
case "SB":
a.Name = obj.NAME_EXTERN
if isStatic != 0 {
a.Name = obj.NAME_STATIC
}
case "SP":
a.Name = obj.NAME_AUTO // The pseudo-stack.
default:
p.errorf("expected SB, FP, or SP offset for %s", name)
}
a.Reg = 0 // There is no register here; these are pseudo-registers.
p.get(')')
}
// Note: There are two changes in the expression handling here
// compared to the old yacc/C implemenatations. Neither has
// much practical consequence because the expressions we

5
src/cmd/asm/internal/lex/lex.go
View File

@ -61,8 +61,9 @@ var (
// HistLine reports the cumulative source line number of the token,
// for use in the Prog structure for the linker. (It's always handling the
// instruction from the current lex line.)
func HistLine() int {
return histLine
// It returns int32 because that's what type ../asm prefers.
func HistLine() int32 {
return int32(histLine)
}
// NewLexer returns a lexer for the named file and the given link context.

7
src/cmd/asm/internal/lex/stack.go
View File

@ -22,13 +22,6 @@ func (s *Stack) Next() ScanToken {
tok := tos.Next()
for tok == scanner.EOF && len(s.tr) > 1 {
tos.Close()
/*
// If it's not a macro (a Slice at this point), pop the line history stack and close the file descriptor.
if _, isMacro := tos.(*Slice); !isMacro {
// TODO: close file descriptor.
obj.Linklinehist(linkCtxt, histLine, "<pop>", 0)
}
*/
// Pop the topmost item from the stack and resume with the next one down.
s.tr = s.tr[:len(s.tr)-1]
tok = s.Next()

2
src/cmd/asm/main.go
View File

@ -1,5 +1,3 @@
// +build ignore
// Copyright 2014 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.