tinygo/tgo.go
2018-04-12 15:19:20 +02:00

296 строки
7,2 КиБ
Go

package main
import (
"errors"
"flag"
"fmt"
"go/ast"
"go/constant"
"go/token"
"os"
"golang.org/x/tools/go/loader"
"llvm.org/llvm/bindings/go/llvm"
)
func init() {
llvm.InitializeAllTargets()
llvm.InitializeAllTargetMCs()
llvm.InitializeAllTargetInfos()
llvm.InitializeAllAsmParsers()
llvm.InitializeAllAsmPrinters()
}
type Compiler struct {
mod llvm.Module
ctx llvm.Context
builder llvm.Builder
machine llvm.TargetMachine
stringType llvm.Type
stringPtrType llvm.Type
printstringFunc llvm.Value
printintFunc llvm.Value
printspaceFunc llvm.Value
printnlFunc llvm.Value
}
func NewCompiler(path, triple string) (*Compiler, error) {
c := &Compiler{}
target, err := llvm.GetTargetFromTriple(triple)
if err != nil {
return nil, err
}
c.machine = target.CreateTargetMachine(triple, "", "", llvm.CodeGenLevelDefault, llvm.RelocDefault, llvm.CodeModelDefault)
c.mod = llvm.NewModule(path)
c.ctx = c.mod.Context()
c.builder = c.ctx.NewBuilder()
// Length-prefixed string.
c.stringType = llvm.StructType([]llvm.Type{llvm.Int32Type(), llvm.ArrayType(llvm.Int8Type(), 0)}, false)
c.stringPtrType = llvm.PointerType(c.stringType, 0)
printstringType := llvm.FunctionType(llvm.VoidType(), []llvm.Type{c.stringPtrType}, false)
c.printstringFunc = llvm.AddFunction(c.mod, "__go_printstring", printstringType)
printintType := llvm.FunctionType(llvm.VoidType(), []llvm.Type{llvm.Int32Type()}, false)
c.printintFunc = llvm.AddFunction(c.mod, "__go_printint", printintType)
printspaceType := llvm.FunctionType(llvm.VoidType(), nil, false)
c.printspaceFunc = llvm.AddFunction(c.mod, "__go_printspace", printspaceType)
printnlType := llvm.FunctionType(llvm.VoidType(), nil, false)
c.printnlFunc = llvm.AddFunction(c.mod, "__go_printnl", printnlType)
return c, nil
}
func (c *Compiler) Parse(path string) error {
config := loader.Config {
// TODO: TypeChecker.Sizes
// TODO: Build (build.Context) - GOOS, GOARCH, GOPATH, etc
}
config.CreateFromFilenames("main", path)
program, err := config.Load()
if err != nil {
return err
}
pkgInfo := program.Created[0] // main?
if len(pkgInfo.Errors) != 0 {
return pkgInfo.Errors[0] // TODO: better error checking
}
fmt.Println("package:", pkgInfo.Pkg.Name())
for _, file := range pkgInfo.Files {
err := c.parseFile(pkgInfo.Pkg.Name(), file)
if err != nil {
return err
}
}
return nil
}
func (c *Compiler) parseFile(pkgName string, file *ast.File) error {
for _, decl := range file.Decls {
switch v := decl.(type) {
case *ast.FuncDecl:
err := c.parseFunc(pkgName, v)
if err != nil {
return err
}
default:
return errors.New("unknown declaration")
}
}
return nil
}
func (c *Compiler) parseFunc(pkgName string, f *ast.FuncDecl) error {
fmt.Println("func:", f.Name)
var fnType llvm.Type
if f.Type.Results == nil {
fnType = llvm.FunctionType(llvm.VoidType(), nil, false)
} else {
return errors.New("todo: return values")
}
fn := llvm.AddFunction(c.mod, pkgName + "." + f.Name.Name, fnType)
start := c.ctx.AddBasicBlock(fn, "start")
c.builder.SetInsertPointAtEnd(start)
// TODO: external functions
for _, stmt := range f.Body.List {
err := c.parseStmt(stmt)
if err != nil {
return err
}
}
if f.Type.Results == nil {
c.builder.CreateRetVoid()
//} else if len(f.Type.Results.List) == 1 {
// c.builder.CreateRet(llvm.ConstInt(llvm.Int32Type(), 0, false))
}
return nil
}
func (c *Compiler) parseStmt(stmt ast.Node) error {
switch v := stmt.(type) {
case *ast.ExprStmt:
err := c.parseExpr(v.X)
if err != nil {
return err
}
default:
return errors.New("unknown stmt")
}
return nil
}
func (c *Compiler) parseExpr(expr ast.Expr) error {
switch v := expr.(type) {
case *ast.CallExpr:
name := v.Fun.(*ast.Ident).Name
fmt.Printf(" call: %s\n", name)
printnl := false
if name == "println" {
printnl = true
} else if name == "print" {
} else {
return errors.New("todo: call anything other than println()")
}
for i, arg := range v.Args {
if i >= 1 {
c.builder.CreateCall(c.printspaceFunc, nil, "")
}
switch arg := arg.(type) {
case *ast.BasicLit:
fmt.Printf(" arg: %s\n", arg.Value)
val := constant.MakeFromLiteral(arg.Value, arg.Kind, 0)
switch arg.Kind {
case token.STRING:
str := constant.StringVal(val)
strVal := c.ctx.ConstString(str, false)
strLen := llvm.ConstInt(llvm.Int32Type(), uint64(len(str)), false)
strObj := llvm.ConstStruct([]llvm.Value{strLen, strVal}, false)
ptr := llvm.AddGlobal(c.mod, strObj.Type(), ".str")
ptr.SetInitializer(strObj)
ptr.SetLinkage(llvm.InternalLinkage)
ptrCast := llvm.ConstPointerCast(ptr, c.stringPtrType)
c.builder.CreateCall(c.printstringFunc, []llvm.Value{ptrCast}, "")
case token.INT:
n, _ := constant.Int64Val(val) // TODO: do something with the 'exact' return value?
val := llvm.ConstInt(llvm.Int32Type(), uint64(n), true)
c.builder.CreateCall(c.printintFunc, []llvm.Value{val}, "")
default:
return errors.New("todo: print anything other than strings")
}
default:
return errors.New("unknown arg type")
}
}
if printnl {
c.builder.CreateCall(c.printnlFunc, nil, "")
}
default:
return errors.New("unknown expr")
}
return nil
}
// IR returns the whole IR as a human-readable string.
func (c *Compiler) IR() string {
return c.mod.String()
}
func (c *Compiler) Verify() error {
return llvm.VerifyModule(c.mod, llvm.PrintMessageAction)
}
func (c *Compiler) Optimize(optLevel int) {
builder := llvm.NewPassManagerBuilder()
defer builder.Dispose()
builder.SetOptLevel(optLevel)
builder.UseInlinerWithThreshold(200) // TODO depend on opt level, and -Os
funcPasses := llvm.NewFunctionPassManagerForModule(c.mod)
defer funcPasses.Dispose()
builder.PopulateFunc(funcPasses)
modPasses := llvm.NewPassManager()
defer modPasses.Dispose()
builder.Populate(modPasses)
modPasses.Run(c.mod)
}
func (c *Compiler) EmitObject(path string) error {
buf, err := c.machine.EmitToMemoryBuffer(c.mod, llvm.ObjectFile)
if err != nil {
return err
}
f, err := os.OpenFile(path, os.O_RDWR|os.O_CREATE, 0666)
if err != nil {
return err
}
f.Write(buf.Bytes())
f.Close()
return nil
}
// Helper function for Compiler object.
func Compile(inpath, outpath, target string, printIR bool) error {
c, err := NewCompiler(inpath, target)
if err != nil {
return err
}
err = c.Parse(inpath)
if err != nil {
return err
}
if err := c.Verify(); err != nil {
return err
}
c.Optimize(2)
if err := c.Verify(); err != nil {
return err
}
if printIR {
fmt.Println(c.IR())
}
err = c.EmitObject(outpath)
if err != nil {
return err
}
return nil
}
func main() {
outpath := flag.String("o", "", "output filename")
target := flag.String("target", llvm.DefaultTargetTriple(), "LLVM target")
printIR := flag.Bool("printir", false, "print LLVM IR after optimizing")
flag.Parse()
if *outpath == "" || flag.NArg() != 1 {
fmt.Fprintf(os.Stderr, "usage: %s [-printir] [-target=<target>] -o <output> <input>", os.Args[0])
flag.PrintDefaults()
return
}
err := Compile(flag.Args()[0], *outpath, *target, *printIR)
if err != nil {
fmt.Fprintln(os.Stderr, "error:", err)
os.Exit(1)
}
}