wip

internal/gen/gen.go

@@ -0,0 +1,34 @@
+package gen
+
+import (
+	"fmt"
+	"io"
+
+	"github.com/mmcloughlin/avo/internal/inst"
+)
+
+type Interface interface {
+	Generate(io.Writer, []*inst.Instruction) error
+}
+
+type Func func(io.Writer, []*inst.Instruction) error
+
+func (f Func) Generate(w io.Writer, is []*inst.Instruction) error {
+	return f(w, is)
+}
+
+type printer struct {
+	w   io.Writer
+	err error
+}
+
+func (p *printer) printf(format string, args ...interface{}) {
+	if p.err != nil {
+		return
+	}
+	_, p.err = fmt.Fprintf(p.w, format, args...)
+}
+
+func (p *printer) Err() error {
+	return p.err
+}

internal/gen/loadertest.go

@@ -0,0 +1,127 @@
+package gen
+
+import (
+	"io"
+	"strings"
+
+	"github.com/mmcloughlin/avo/internal/inst"
+)
+
+type LoaderTest struct{}
+
+func (l LoaderTest) Generate(w io.Writer, is []*inst.Instruction) error {
+	p := &printer{w: w}
+
+	p.printf("TEXT loadertest(SB), 0, $0\n")
+
+	for _, i := range is {
+		p.printf("\t// %s %s\n", i.Opcode, i.Summary)
+		for _, f := range i.Forms {
+			as := args(f.Operands)
+			p.printf("\t// %#v\n", f.Operands)
+			if as == nil {
+				p.printf("\t// skip\n")
+				continue
+			}
+			p.printf("\t%s\t%s\n", i.Opcode, strings.Join(as, ", "))
+		}
+		p.printf("\n")
+	}
+
+	p.printf("\tRET\n")
+
+	return p.Err()
+}
+
+func args(ops []inst.Operand) []string {
+	as := make([]string, len(ops))
+	for i, op := range ops {
+		a := arg(op.Type)
+		if a == "" {
+			return nil
+		}
+		as[i] = a
+	}
+	return as
+}
+
+// arg generates an argument for an operand of the given type.
+func arg(t string) string {
+	m := map[string]string{
+		// <xs:enumeration value="1" />
+		// <xs:enumeration value="3" />
+		// <xs:enumeration value="imm4" />
+		// <xs:enumeration value="imm8" />
+		// <xs:enumeration value="imm16" />
+		// <xs:enumeration value="imm32" />
+		// <xs:enumeration value="imm64" />
+		// <xs:enumeration value="al" />
+		// <xs:enumeration value="cl" />
+		// <xs:enumeration value="r8" />
+		// <xs:enumeration value="r8l" />
+		// <xs:enumeration value="ax" />
+		// <xs:enumeration value="r16" />
+		// <xs:enumeration value="r16l" />
+		// <xs:enumeration value="eax" />
+		// <xs:enumeration value="r32" />
+		// <xs:enumeration value="r32l" />
+		// <xs:enumeration value="rax" />
+		// <xs:enumeration value="r64" />
+		"r64": "R8",
+		// <xs:enumeration value="mm" />
+		// <xs:enumeration value="xmm0" />
+		// <xs:enumeration value="xmm" />
+		// <xs:enumeration value="xmm{k}" />
+		// <xs:enumeration value="xmm{k}{z}" />
+		// <xs:enumeration value="ymm" />
+		// <xs:enumeration value="ymm{k}" />
+		// <xs:enumeration value="ymm{k}{z}" />
+		// <xs:enumeration value="zmm" />
+		// <xs:enumeration value="zmm{k}" />
+		// <xs:enumeration value="zmm{k}{z}" />
+		// <xs:enumeration value="k" />
+		// <xs:enumeration value="k{k}" />
+		// <xs:enumeration value="moffs32" />
+		// <xs:enumeration value="moffs64" />
+		// <xs:enumeration value="m" />
+		// <xs:enumeration value="m8" />
+		// <xs:enumeration value="m16" />
+		// <xs:enumeration value="m16{k}{z}" />
+		// <xs:enumeration value="m32" />
+		// <xs:enumeration value="m32{k}" />
+		// <xs:enumeration value="m32{k}{z}" />
+		// <xs:enumeration value="m64" />
+		// <xs:enumeration value="m64{k}" />
+		// <xs:enumeration value="m64{k}{z}" />
+		// <xs:enumeration value="m128" />
+		// <xs:enumeration value="m128{k}{z}" />
+		// <xs:enumeration value="m256" />
+		// <xs:enumeration value="m256{k}{z}" />
+		// <xs:enumeration value="m512" />
+		// <xs:enumeration value="m512{k}{z}" />
+		// <xs:enumeration value="m64/m32bcst" />
+		// <xs:enumeration value="m128/m32bcst" />
+		// <xs:enumeration value="m256/m32bcst" />
+		// <xs:enumeration value="m512/m32bcst" />
+		// <xs:enumeration value="m128/m64bcst" />
+		// <xs:enumeration value="m256/m64bcst" />
+		// <xs:enumeration value="m512/m64bcst" />
+		// <xs:enumeration value="vm32x" />
+		// <xs:enumeration value="vm32x{k}" />
+		// <xs:enumeration value="vm64x" />
+		// <xs:enumeration value="vm64x{k}" />
+		// <xs:enumeration value="vm32y" />
+		// <xs:enumeration value="vm32y{k}" />
+		// <xs:enumeration value="vm64y" />
+		// <xs:enumeration value="vm64y{k}" />
+		// <xs:enumeration value="vm32z" />
+		// <xs:enumeration value="vm32z{k}" />
+		// <xs:enumeration value="vm64z" />
+		// <xs:enumeration value="vm64z{k}" />
+		// <xs:enumeration value="rel8" />
+		// <xs:enumeration value="rel32" />
+		// <xs:enumeration value="{er}" />
+		// <xs:enumeration value="{sae}" />
+	}
+	return m[t]
+}

internal/inst/types.go

@@ -2,6 +2,7 @@ package inst
 
 type Instruction struct {
 	Opcode  string
+	Summary string
 	Forms   []Form
 }
 
@@ -22,3 +23,33 @@ const (
 	W  Action = 0x2
 	RW Action = R | W
 )
+
+func ActionFromReadWrite(r, w bool) Action {
+	var a Action
+	if r {
+		a |= R
+	}
+	if w {
+		a |= W
+	}
+	return a
+}
+
+func (a Action) Read() bool {
+	return (a & R) != 0
+}
+
+func (a Action) Write() bool {
+	return (a & W) != 0
+}
+
+func (a Action) String() string {
+	s := ""
+	if a.Read() {
+		s += "r"
+	}
+	if a.Write() {
+		s += "w"
+	}
+	return s
+}

internal/load/ifind.sh

@@ -0,0 +1,20 @@
+#!/bin/bash
+
+inst=$1
+
+eval $(go env)
+
+section() {
+    echo '------------------------------------------'
+    echo $1
+    echo '------------------------------------------'
+}
+
+section 'stdlib cmd/'
+grep -iR ${inst} ${GOROOT}/src/cmd/{asm,internal/obj/x86}
+
+section 'x/arch/x86 repo'
+grep -iR ${inst} ${GOPATH}/src/golang.org/x/arch/x86/
+
+section '*_amd64.s files in stdlib'
+find ${GOROOT}/src -name '*_amd64.s' | xargs grep -i ${inst}

internal/load/load.go

@@ -0,0 +1,181 @@
+package load
+
+import (
+	"path/filepath"
+	"strconv"
+	"strings"
+
+	"github.com/mmcloughlin/avo/internal/inst"
+	"github.com/mmcloughlin/avo/internal/opcodescsv"
+	"github.com/mmcloughlin/avo/internal/opcodesxml"
+)
+
+const (
+	defaultCSVName        = "x86.v0.2.csv"
+	defaultOpcodesXMLName = "x86_64.xml"
+)
+
+type Loader struct {
+	X86CSVPath     string
+	OpcodesXMLPath string
+
+	alias map[opcodescsv.Alias]string
+}
+
+func NewLoaderFromDataDir(dir string) *Loader {
+	return &Loader{
+		X86CSVPath:     filepath.Join(dir, defaultCSVName),
+		OpcodesXMLPath: filepath.Join(dir, defaultOpcodesXMLName),
+	}
+}
+
+func (l *Loader) Load() ([]*inst.Instruction, error) {
+	if err := l.init(); err != nil {
+		return nil, err
+	}
+
+	// Load Opcodes XML file.
+	iset, err := opcodesxml.ReadFile(l.OpcodesXMLPath)
+	if err != nil {
+		return nil, err
+	}
+
+	// Load opcodes XML data, grouped by Go opcode.
+	im := map[string]*inst.Instruction{}
+	for _, i := range iset.Instructions {
+		for _, f := range i.Forms {
+			if !l.include(f) {
+				continue
+			}
+
+			opcode := l.goname(f)
+
+			if im[opcode] == nil {
+				im[opcode] = &inst.Instruction{
+					Opcode:  opcode,
+					Summary: i.Summary,
+				}
+			}
+
+			im[opcode].Forms = append(im[opcode].Forms, l.form(f))
+		}
+	}
+
+	// Convert to a slice to return.
+	is := make([]*inst.Instruction, 0, len(im))
+	for _, i := range im {
+		is = append(is, i)
+	}
+
+	return is, nil
+}
+
+func (l *Loader) init() error {
+	icsv, err := opcodescsv.ReadFile(l.X86CSVPath)
+	if err != nil {
+		return err
+	}
+
+	l.alias, err = opcodescsv.BuildAliasMap(icsv)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// include decides whether to include the instruction form in the avo listing.
+// This discards some opcodes that are not supported in Go.
+func (l Loader) include(f opcodesxml.Form) bool {
+	// Exclude certain ISAs simply not present in Go.
+	for _, isa := range f.ISA {
+		switch isa.ID {
+		case "TBM", "CLZERO", "MONITORX", "FEMMS":
+			return false
+		}
+	}
+
+	// x86 csv contains a number of CMOV* instructions which are actually not valid
+	// Go instructions. The valid Go forms should have different opcodes from GNU.
+	// Therefore a decent "heuristic" is CMOV* instructions that do not have
+	// aliases.
+	if strings.HasPrefix(f.GASName, "cmov") && l.lookupAlias(f) == "" {
+		return false
+	}
+
+	// Some specific exclusions.
+	switch f.GASName {
+	case "callq":
+		return false
+	}
+
+	return true
+}
+
+func (l Loader) lookupAlias(f opcodesxml.Form) string {
+	a := opcodescsv.Alias{Opcode: f.GASName, DataSize: datasize(f)}
+	return l.alias[a]
+}
+
+func (l Loader) goname(f opcodesxml.Form) string {
+	// Use go opcode from Opcodes XML where available.
+	if f.GoName != "" {
+		return f.GoName
+	}
+
+	// Return alias if available.
+	if a := l.lookupAlias(f); a != "" {
+		return a
+	}
+
+	n := strings.ToUpper(f.GASName)
+
+	// Some need data sizes added to them.
+	// TODO(mbm): is there a better way of determining which ones these are?
+	s := datasize(f)
+	suffix := map[int]string{16: "W", 32: "L", 64: "Q"}
+	switch n {
+	case "RDRAND", "RDSEED":
+		n += suffix[s]
+	}
+
+	return n
+}
+
+func (l Loader) form(f opcodesxml.Form) inst.Form {
+	return inst.Form{
+		Operands: operands(f.Operands),
+	}
+}
+
+// operands maps Opcodes XML operands to avo format.
+func operands(ops []opcodesxml.Operand) []inst.Operand {
+	r := make([]inst.Operand, 0, len(ops))
+	for _, op := range ops {
+		r = append(r, operand(op))
+	}
+	return r
+}
+
+// operand maps an Opcodes XML operand to avo format.
+func operand(op opcodesxml.Operand) inst.Operand {
+	return inst.Operand{
+		Type:   op.Type,
+		Action: inst.ActionFromReadWrite(op.Input, op.Output),
+	}
+}
+
+// datasize (intelligently) guesses the datasize of an instruction form.
+func datasize(f opcodesxml.Form) int {
+	for _, op := range f.Operands {
+		if !op.Output {
+			continue
+		}
+		for s := 8; s <= 64; s *= 2 {
+			if strings.HasSuffix(op.Type, strconv.Itoa(s)) {
+				return s
+			}
+		}
+	}
+	return 0
+}

internal/load/load_test.go

@@ -0,0 +1,31 @@
+package load_test
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/mmcloughlin/avo/internal/gen"
+	"github.com/mmcloughlin/avo/internal/inst"
+	"github.com/mmcloughlin/avo/internal/load"
+	"github.com/mmcloughlin/avo/internal/test"
+)
+
+func Load(t *testing.T) []*inst.Instruction {
+	t.Helper()
+	l := load.NewLoaderFromDataDir("testdata")
+	is, err := l.Load()
+	if err != nil {
+		t.Fatal(err)
+	}
+	return is
+}
+
+func TestAssembles(t *testing.T) {
+	is := Load(t)
+
+	g := &gen.LoaderTest{}
+	var buf bytes.Buffer
+	g.Generate(&buf, is)
+
+	test.Assembles(t, buf.Bytes())
+}

internal/load/testdata

@@ -0,0 +1 @@
+../data

internal/opcodescsv/analysis.go

@@ -0,0 +1,38 @@
+package opcodescsv
+
+import (
+	"strconv"
+	"strings"
+
+	"golang.org/x/arch/x86/x86csv"
+)
+
+type Alias struct {
+	Opcode   string
+	DataSize int
+}
+
+// BuildAliasMap constructs a map from AT&T/GNU/Intel to Go syntax.
+func BuildAliasMap(is []*x86csv.Inst) (map[Alias]string, error) {
+	m := map[Alias]string{}
+	for _, i := range is {
+		s, err := datasize(i.DataSize)
+		if err != nil {
+			return nil, err
+		}
+
+		for _, alt := range []string{i.IntelOpcode(), i.GNUOpcode()} {
+			if strings.ToUpper(alt) != i.GoOpcode() {
+				m[Alias{Opcode: strings.ToLower(alt), DataSize: s}] = i.GoOpcode()
+			}
+		}
+	}
+	return m, nil
+}
+
+func datasize(s string) (int, error) {
+	if s == "" {
+		return 0, nil
+	}
+	return strconv.Atoi(s)
+}

internal/opcodescsv/io.go

@@ -0,0 +1,19 @@
+package opcodescsv
+
+import (
+	"os"
+
+	"golang.org/x/arch/x86/x86csv"
+)
+
+// ReadFile reads the given x86 CSV file.
+func ReadFile(filename string) ([]*x86csv.Inst, error) {
+	f, err := os.Open(filename)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	r := x86csv.NewReader(f)
+	return r.ReadAll()
+}

internal/test/utils.go

@@ -0,0 +1,69 @@
+package test
+
+import (
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"testing"
+)
+
+// Assembles asserts that the given assembly code passes the go assembler.
+func Assembles(t *testing.T, asm []byte) {
+	t.Helper()
+
+	dir, clean := TempDir(t)
+	defer clean()
+
+	asmfilename := filepath.Join(dir, "asm.s")
+	if err := ioutil.WriteFile(asmfilename, asm, 0600); err != nil {
+		t.Fatal(err)
+	}
+
+	objfilename := filepath.Join(dir, "asm.o")
+
+	goexec(t, "tool", "asm", "-e", "-o", objfilename, asmfilename)
+}
+
+// TempDir creates a temp directory. Returns the path to the directory and a
+// cleanup function.
+func TempDir(t *testing.T) (string, func()) {
+	t.Helper()
+
+	dir, err := ioutil.TempDir("", "avo")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	return dir, func() {
+		if err := os.RemoveAll(dir); err != nil {
+			t.Fatal(err)
+		}
+	}
+}
+
+// gobin returns a best guess path to the "go" binary.
+func gobin() string {
+	var exeSuffix string
+	if runtime.GOOS == "windows" {
+		exeSuffix = ".exe"
+	}
+	path := filepath.Join(runtime.GOROOT(), "bin", "go"+exeSuffix)
+	if _, err := os.Stat(path); err == nil {
+		return path
+	}
+	return "go"
+}
+
+// goexec runs a "go" command and checks the output.
+func goexec(t *testing.T, arg ...string) {
+	t.Helper()
+	cmd := exec.Command(gobin(), arg...)
+	t.Logf("exec: %s", cmd.Args)
+	b, err := cmd.CombinedOutput()
+	t.Logf("output:\n%s\n", string(b))
+	if err != nil {
+		t.Fatal(err)
+	}
+}