softonik/tinygo
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Код Задачи Слияния Проекты Выпуски Пакеты Вики Активность Действия
tinygo/compiler/compiler.go
Ayke van Laethem 2a0a7722f9 compiler: lower func values to switch + direct call 
This has several advantages, among them:
  - Many passes (heap-to-stack, dead arg elimination, inlining) do not
    work with function pointer calls. Making them normal function calls
    improves their effectiveness.
  - Goroutine lowering to LLVM coroutines does not currently support
    function pointers. By eliminating function pointers, coroutine
    lowering gets support for them for free.
    This is especially useful for WebAssembly.
Because of the second point, this work is currently only enabled for the
WebAssembly target.
2019-04-17 23:12:59 +02:00

2796 строки
93 КиБ
Go
Исходный Авторство История

package compiler
import (
"errors"
"fmt"
"go/build"
"go/constant"
"go/token"
"go/types"
"os"
"path/filepath"
"runtime"
"strconv"
"strings"
"github.com/tinygo-org/tinygo/ir"
"github.com/tinygo-org/tinygo/loader"
"golang.org/x/tools/go/ssa"
"tinygo.org/x/go-llvm"
)
func init() {
llvm.InitializeAllTargets()
llvm.InitializeAllTargetMCs()
llvm.InitializeAllTargetInfos()
llvm.InitializeAllAsmParsers()
llvm.InitializeAllAsmPrinters()
}
// Configure the compiler.
type Config struct {
Triple string // LLVM target triple, e.g. x86_64-unknown-linux-gnu (empty string means default)
CPU string // LLVM CPU name, e.g. atmega328p (empty string means default)
GOOS string //
GOARCH string //
GC string // garbage collection strategy
CFlags []string // cflags to pass to cgo
LDFlags []string // ldflags to pass to cgo
DumpSSA bool // dump Go SSA, for compiler debugging
Debug bool // add debug symbols for gdb
RootDir string // GOROOT for TinyGo
GOPATH string // GOPATH, like `go env GOPATH`
BuildTags []string // build tags for TinyGo (empty means {Config.GOOS/Config.GOARCH})
}
type Compiler struct {
Config
mod llvm.Module
ctx llvm.Context
builder llvm.Builder
dibuilder *llvm.DIBuilder
cu llvm.Metadata
difiles map[string]llvm.Metadata
ditypes map[string]llvm.Metadata
machine llvm.TargetMachine
targetData llvm.TargetData
intType llvm.Type
i8ptrType llvm.Type // for convenience
funcPtrAddrSpace int
uintptrType llvm.Type
initFuncs []llvm.Value
interfaceInvokeWrappers []interfaceInvokeWrapper
ir *ir.Program
}
type Frame struct {
fn *ir.Function
locals map[ssa.Value]llvm.Value // local variables
blockEntries map[*ssa.BasicBlock]llvm.BasicBlock // a *ssa.BasicBlock may be split up
blockExits map[*ssa.BasicBlock]llvm.BasicBlock // these are the exit blocks
currentBlock *ssa.BasicBlock
phis []Phi
taskHandle llvm.Value
deferPtr llvm.Value
difunc llvm.Metadata
allDeferFuncs []interface{}
deferFuncs map[*ir.Function]int
deferInvokeFuncs map[string]int
deferClosureFuncs map[*ir.Function]int
}
type Phi struct {
ssa *ssa.Phi
llvm llvm.Value
}
func NewCompiler(pkgName string, config Config) (*Compiler, error) {
if config.Triple == "" {
config.Triple = llvm.DefaultTargetTriple()
}
if len(config.BuildTags) == 0 {
config.BuildTags = []string{config.GOOS, config.GOARCH}
}
c := &Compiler{
Config: config,
difiles: make(map[string]llvm.Metadata),
ditypes: make(map[string]llvm.Metadata),
}
target, err := llvm.GetTargetFromTriple(config.Triple)
if err != nil {
return nil, err
}
c.machine = target.CreateTargetMachine(config.Triple, config.CPU, "", llvm.CodeGenLevelDefault, llvm.RelocStatic, llvm.CodeModelDefault)
c.targetData = c.machine.CreateTargetData()
c.ctx = llvm.NewContext()
c.mod = c.ctx.NewModule(pkgName)
c.mod.SetTarget(config.Triple)
c.mod.SetDataLayout(c.targetData.String())
c.builder = c.ctx.NewBuilder()
if c.Debug {
c.dibuilder = llvm.NewDIBuilder(c.mod)
}
c.uintptrType = c.ctx.IntType(c.targetData.PointerSize() * 8)
if c.targetData.PointerSize() <= 4 {
// 8, 16, 32 bits targets
c.intType = c.ctx.Int32Type()
} else if c.targetData.PointerSize() == 8 {
// 64 bits target
c.intType = c.ctx.Int64Type()
} else {
panic("unknown pointer size")
}
c.i8ptrType = llvm.PointerType(c.ctx.Int8Type(), 0)
dummyFuncType := llvm.FunctionType(c.ctx.VoidType(), nil, false)
dummyFunc := llvm.AddFunction(c.mod, "tinygo.dummy", dummyFuncType)
c.funcPtrAddrSpace = dummyFunc.Type().PointerAddressSpace()
dummyFunc.EraseFromParentAsFunction()
return c, nil
}
func (c *Compiler) Packages() []*loader.Package {
return c.ir.LoaderProgram.Sorted()
}
// Return the LLVM module. Only valid after a successful compile.
func (c *Compiler) Module() llvm.Module {
return c.mod
}
// Return the LLVM target data object. Only valid after a successful compile.
func (c *Compiler) TargetData() llvm.TargetData {
return c.targetData
}
// selectGC picks an appropriate GC strategy if none was provided.
func (c *Compiler) selectGC() string {
gc := c.GC
if gc == "" {
gc = "dumb"
}
return gc
}
// Compile the given package path or .go file path. Return an error when this
// fails (in any stage).
func (c *Compiler) Compile(mainPath string) error {
// Prefix the GOPATH with the system GOROOT, as GOROOT is already set to
// the TinyGo root.
overlayGopath := c.GOPATH
if overlayGopath == "" {
overlayGopath = runtime.GOROOT()
} else {
overlayGopath = runtime.GOROOT() + string(filepath.ListSeparator) + overlayGopath
}
wd, err := os.Getwd()
if err != nil {
return err
}
lprogram := &loader.Program{
Build: &build.Context{
GOARCH: c.GOARCH,
GOOS: c.GOOS,
GOROOT: runtime.GOROOT(),
GOPATH: c.GOPATH,
CgoEnabled: true,
UseAllFiles: false,
Compiler: "gc", // must be one of the recognized compilers
BuildTags: append([]string{"tinygo", "gc." + c.selectGC()}, c.BuildTags...),
},
OverlayBuild: &build.Context{
GOARCH: c.GOARCH,
GOOS: c.GOOS,
GOROOT: c.RootDir,
GOPATH: overlayGopath,
CgoEnabled: true,
UseAllFiles: false,
Compiler: "gc", // must be one of the recognized compilers
BuildTags: append([]string{"tinygo", "gc." + c.selectGC()}, c.BuildTags...),
},
ShouldOverlay: func(path string) bool {
switch path {
case "machine", "os", "reflect", "runtime", "sync":
return true
default:
if strings.HasPrefix(path, "device/") || strings.HasPrefix(path, "examples/") {
return true
} else if path == "syscall" {
for _, tag := range c.BuildTags {
if tag == "avr" || tag == "cortexm" || tag == "darwin" {
return true
}
}
}
}
return false
},
TypeChecker: types.Config{
Sizes: &StdSizes{
IntSize: int64(c.targetData.TypeAllocSize(c.intType)),
PtrSize: int64(c.targetData.PointerSize()),
MaxAlign: int64(c.targetData.PrefTypeAlignment(c.i8ptrType)),
},
},
Dir: wd,
CFlags: c.CFlags,
}
if strings.HasSuffix(mainPath, ".go") {
_, err = lprogram.ImportFile(mainPath)
if err != nil {
return err
}
} else {
_, err = lprogram.Import(mainPath, wd)
if err != nil {
return err
}
}
_, err = lprogram.Import("runtime", "")
if err != nil {
return err
}
err = lprogram.Parse()
if err != nil {
return err
}
c.ir = ir.NewProgram(lprogram, mainPath)
// Run a simple dead code elimination pass.
c.ir.SimpleDCE()
// Initialize debug information.
if c.Debug {
c.cu = c.dibuilder.CreateCompileUnit(llvm.DICompileUnit{
Language: llvm.DW_LANG_Go,
File: mainPath,
Dir: "",
Producer: "TinyGo",
Optimized: true,
})
}
var frames []*Frame
// Declare all named struct types.
for _, t := range c.ir.NamedTypes {
if named, ok := t.Type.Type().(*types.Named); ok {
if _, ok := named.Underlying().(*types.Struct); ok {
t.LLVMType = c.ctx.StructCreateNamed(named.Obj().Pkg().Path() + "." + named.Obj().Name())
}
}
}
// Define all named struct types.
for _, t := range c.ir.NamedTypes {
if named, ok := t.Type.Type().(*types.Named); ok {
if st, ok := named.Underlying().(*types.Struct); ok {
llvmType, err := c.getLLVMType(st)
if err != nil {
return err
}
t.LLVMType.StructSetBody(llvmType.StructElementTypes(), false)
}
}
}
// Declare all globals.
for _, g := range c.ir.Globals {
typ := g.Type().(*types.Pointer).Elem()
llvmType, err := c.getLLVMType(typ)
if err != nil {
return err
}
global := c.mod.NamedGlobal(g.LinkName())
if global.IsNil() {
global = llvm.AddGlobal(c.mod, llvmType, g.LinkName())
}
g.LLVMGlobal = global
if !g.IsExtern() {
global.SetLinkage(llvm.InternalLinkage)
initializer, err := c.getZeroValue(llvmType)
if err != nil {
return err
}
global.SetInitializer(initializer)
}
}
// Declare all functions.
for _, f := range c.ir.Functions {
frame, err := c.parseFuncDecl(f)
if err != nil {
return err
}
frames = append(frames, frame)
}
// Add definitions to declarations.
for _, frame := range frames {
if frame.fn.Synthetic == "package initializer" {
c.initFuncs = append(c.initFuncs, frame.fn.LLVMFn)
}
if frame.fn.CName() != "" {
continue
}
if frame.fn.Blocks == nil {
continue // external function
}
err := c.parseFunc(frame)
if err != nil {
return err
}
}
// Define the already declared functions that wrap methods for use in
// interfaces.
for _, state := range c.interfaceInvokeWrappers {
err = c.createInterfaceInvokeWrapper(state)
if err != nil {
return err
}
}
// After all packages are imported, add a synthetic initializer function
// that calls the initializer of each package.
initFn := c.ir.GetFunction(c.ir.Program.ImportedPackage("runtime").Members["initAll"].(*ssa.Function))
initFn.LLVMFn.SetLinkage(llvm.InternalLinkage)
initFn.LLVMFn.SetUnnamedAddr(true)
if c.Debug {
difunc, err := c.attachDebugInfo(initFn)
if err != nil {
return err
}
pos := c.ir.Program.Fset.Position(initFn.Pos())
c.builder.SetCurrentDebugLocation(uint(pos.Line), uint(pos.Column), difunc, llvm.Metadata{})
}
block := c.ctx.AddBasicBlock(initFn.LLVMFn, "entry")
c.builder.SetInsertPointAtEnd(block)
for _, fn := range c.initFuncs {
c.builder.CreateCall(fn, []llvm.Value{llvm.Undef(c.i8ptrType), llvm.Undef(c.i8ptrType)}, "")
}
c.builder.CreateRetVoid()
// Conserve for goroutine lowering. Without marking these as external, they
// would be optimized away.
realMain := c.mod.NamedFunction(c.ir.MainPkg().Pkg.Path() + ".main")
realMain.SetLinkage(llvm.ExternalLinkage) // keep alive until goroutine lowering
c.mod.NamedFunction("runtime.alloc").SetLinkage(llvm.ExternalLinkage)
c.mod.NamedFunction("runtime.free").SetLinkage(llvm.ExternalLinkage)
c.mod.NamedFunction("runtime.chanSend").SetLinkage(llvm.ExternalLinkage)
c.mod.NamedFunction("runtime.chanRecv").SetLinkage(llvm.ExternalLinkage)
c.mod.NamedFunction("runtime.sleepTask").SetLinkage(llvm.ExternalLinkage)
c.mod.NamedFunction("runtime.activateTask").SetLinkage(llvm.ExternalLinkage)
c.mod.NamedFunction("runtime.scheduler").SetLinkage(llvm.ExternalLinkage)
// Load some attributes
getAttr := func(attrName string) llvm.Attribute {
attrKind := llvm.AttributeKindID(attrName)
return c.ctx.CreateEnumAttribute(attrKind, 0)
}
nocapture := getAttr("nocapture")
writeonly := getAttr("writeonly")
readonly := getAttr("readonly")
// Tell the optimizer that runtime.alloc is an allocator, meaning that it
// returns values that are never null and never alias to an existing value.
for _, attrName := range []string{"noalias", "nonnull"} {
c.mod.NamedFunction("runtime.alloc").AddAttributeAtIndex(0, getAttr(attrName))
}
// See emitNilCheck in asserts.go.
c.mod.NamedFunction("runtime.isnil").AddAttributeAtIndex(1, nocapture)
// Memory copy operations do not capture pointers, even though some weird
// pointer arithmetic is happening in the Go implementation.
for _, fnName := range []string{"runtime.memcpy", "runtime.memmove"} {
fn := c.mod.NamedFunction(fnName)
fn.AddAttributeAtIndex(1, nocapture)
fn.AddAttributeAtIndex(1, writeonly)
fn.AddAttributeAtIndex(2, nocapture)
fn.AddAttributeAtIndex(2, readonly)
}
// see: https://reviews.llvm.org/D18355
if c.Debug {
c.mod.AddNamedMetadataOperand("llvm.module.flags",
c.ctx.MDNode([]llvm.Metadata{
llvm.ConstInt(c.ctx.Int32Type(), 1, false).ConstantAsMetadata(), // Error on mismatch
llvm.GlobalContext().MDString("Debug Info Version"),
llvm.ConstInt(c.ctx.Int32Type(), 3, false).ConstantAsMetadata(), // DWARF version
}),
)
c.dibuilder.Finalize()
}
return nil
}
func (c *Compiler) getLLVMType(goType types.Type) (llvm.Type, error) {
switch typ := goType.(type) {
case *types.Array:
elemType, err := c.getLLVMType(typ.Elem())
if err != nil {
return llvm.Type{}, err
}
return llvm.ArrayType(elemType, int(typ.Len())), nil
case *types.Basic:
switch typ.Kind() {
case types.Bool, types.UntypedBool:
return c.ctx.Int1Type(), nil
case types.Int8, types.Uint8:
return c.ctx.Int8Type(), nil
case types.Int16, types.Uint16:
return c.ctx.Int16Type(), nil
case types.Int32, types.Uint32:
return c.ctx.Int32Type(), nil
case types.Int, types.Uint:
return c.intType, nil
case types.Int64, types.Uint64:
return c.ctx.Int64Type(), nil
case types.Float32:
return c.ctx.FloatType(), nil
case types.Float64:
return c.ctx.DoubleType(), nil
case types.Complex64:
return c.ctx.StructType([]llvm.Type{c.ctx.FloatType(), c.ctx.FloatType()}, false), nil
case types.Complex128:
return c.ctx.StructType([]llvm.Type{c.ctx.DoubleType(), c.ctx.DoubleType()}, false), nil
case types.String, types.UntypedString:
return c.mod.GetTypeByName("runtime._string"), nil
case types.Uintptr:
return c.uintptrType, nil
case types.UnsafePointer:
return c.i8ptrType, nil
default:
return llvm.Type{}, errors.New("todo: unknown basic type: " + typ.String())
}
case *types.Chan:
return llvm.PointerType(c.mod.GetTypeByName("runtime.channel"), 0), nil
case *types.Interface:
return c.mod.GetTypeByName("runtime._interface"), nil
case *types.Map:
return llvm.PointerType(c.mod.GetTypeByName("runtime.hashmap"), 0), nil
case *types.Named:
if _, ok := typ.Underlying().(*types.Struct); ok {
llvmType := c.mod.GetTypeByName(typ.Obj().Pkg().Path() + "." + typ.Obj().Name())
if llvmType.IsNil() {
return llvm.Type{}, errors.New("type not found: " + typ.Obj().Pkg().Path() + "." + typ.Obj().Name())
}
return llvmType, nil
}
return c.getLLVMType(typ.Underlying())
case *types.Pointer:
ptrTo, err := c.getLLVMType(typ.Elem())
if err != nil {
return llvm.Type{}, err
}
return llvm.PointerType(ptrTo, 0), nil
case *types.Signature: // function value
return c.getFuncType(typ)
case *types.Slice:
elemType, err := c.getLLVMType(typ.Elem())
if err != nil {
return llvm.Type{}, err
}
members := []llvm.Type{
llvm.PointerType(elemType, 0),
c.uintptrType, // len
c.uintptrType, // cap
}
return c.ctx.StructType(members, false), nil
case *types.Struct:
members := make([]llvm.Type, typ.NumFields())
for i := 0; i < typ.NumFields(); i++ {
member, err := c.getLLVMType(typ.Field(i).Type())
if err != nil {
return llvm.Type{}, err
}
members[i] = member
}
if len(members) > 2 && typ.Field(0).Name() == "C union" {
// Not a normal struct but a C union emitted by cgo.
// Such a field name cannot be entered in regular Go code, this must
// be manually inserted in the AST so this is safe.
maxAlign := 0
maxSize := uint64(0)
mainType := members[0]
for _, member := range members {
align := c.targetData.ABITypeAlignment(member)
size := c.targetData.TypeAllocSize(member)
if align > maxAlign {
maxAlign = align
mainType = member
} else if align == maxAlign && size > maxSize {
maxAlign = align
maxSize = size
mainType = member
} else if size > maxSize {
maxSize = size
}
}
members = []llvm.Type{mainType}
mainTypeSize := c.targetData.TypeAllocSize(mainType)
if mainTypeSize < maxSize {
members = append(members, llvm.ArrayType(c.ctx.Int8Type(), int(maxSize-mainTypeSize)))
}
}
return c.ctx.StructType(members, false), nil
case *types.Tuple:
members := make([]llvm.Type, typ.Len())
for i := 0; i < typ.Len(); i++ {
member, err := c.getLLVMType(typ.At(i).Type())
if err != nil {
return llvm.Type{}, err
}
members[i] = member
}
return c.ctx.StructType(members, false), nil
default:
return llvm.Type{}, errors.New("todo: unknown type: " + goType.String())
}
}
// Return a zero LLVM value for any LLVM type. Setting this value as an
// initializer has the same effect as setting 'zeroinitializer' on a value.
// Sadly, I haven't found a way to do it directly with the Go API but this works
// just fine.
func (c *Compiler) getZeroValue(typ llvm.Type) (llvm.Value, error) {
switch typ.TypeKind() {
case llvm.ArrayTypeKind:
subTyp := typ.ElementType()
subVal, err := c.getZeroValue(subTyp)
if err != nil {
return llvm.Value{}, err
}
vals := make([]llvm.Value, typ.ArrayLength())
for i := range vals {
vals[i] = subVal
}
return llvm.ConstArray(subTyp, vals), nil
case llvm.FloatTypeKind, llvm.DoubleTypeKind:
return llvm.ConstFloat(typ, 0.0), nil
case llvm.IntegerTypeKind:
return llvm.ConstInt(typ, 0, false), nil
case llvm.PointerTypeKind:
return llvm.ConstPointerNull(typ), nil
case llvm.StructTypeKind:
types := typ.StructElementTypes()
vals := make([]llvm.Value, len(types))
for i, subTyp := range types {
val, err := c.getZeroValue(subTyp)
if err != nil {
return llvm.Value{}, err
}
vals[i] = val
}
if typ.StructName() != "" {
return llvm.ConstNamedStruct(typ, vals), nil
} else {
return c.ctx.ConstStruct(vals, false), nil
}
default:
return llvm.Value{}, errors.New("todo: LLVM zero initializer: " + typ.String())
}
}
// Is this a pointer type of some sort? Can be unsafe.Pointer or any *T pointer.
func isPointer(typ types.Type) bool {
if _, ok := typ.(*types.Pointer); ok {
return true
} else if typ, ok := typ.(*types.Basic); ok && typ.Kind() == types.UnsafePointer {
return true
} else {
return false
}
}
// Get the DWARF type for this Go type.
func (c *Compiler) getDIType(typ types.Type) (llvm.Metadata, error) {
name := typ.String()
if dityp, ok := c.ditypes[name]; ok {
return dityp, nil
} else {
llvmType, err := c.getLLVMType(typ)
if err != nil {
return llvm.Metadata{}, err
}
sizeInBytes := c.targetData.TypeAllocSize(llvmType)
var encoding llvm.DwarfTypeEncoding
switch typ := typ.(type) {
case *types.Basic:
if typ.Info()&types.IsBoolean != 0 {
encoding = llvm.DW_ATE_boolean
} else if typ.Info()&types.IsFloat != 0 {
encoding = llvm.DW_ATE_float
} else if typ.Info()&types.IsComplex != 0 {
encoding = llvm.DW_ATE_complex_float
} else if typ.Info()&types.IsUnsigned != 0 {
encoding = llvm.DW_ATE_unsigned
} else if typ.Info()&types.IsInteger != 0 {
encoding = llvm.DW_ATE_signed
} else if typ.Kind() == types.UnsafePointer {
encoding = llvm.DW_ATE_address
}
case *types.Pointer:
encoding = llvm.DW_ATE_address
}
// TODO: other types
dityp = c.dibuilder.CreateBasicType(llvm.DIBasicType{
Name: name,
SizeInBits: sizeInBytes * 8,
Encoding: encoding,
})
c.ditypes[name] = dityp
return dityp, nil
}
}
func (c *Compiler) parseFuncDecl(f *ir.Function) (*Frame, error) {
frame := &Frame{
fn: f,
locals: make(map[ssa.Value]llvm.Value),
blockEntries: make(map[*ssa.BasicBlock]llvm.BasicBlock),
blockExits: make(map[*ssa.BasicBlock]llvm.BasicBlock),
}
var retType llvm.Type
if f.Signature.Results() == nil {
retType = c.ctx.VoidType()
} else if f.Signature.Results().Len() == 1 {
var err error
retType, err = c.getLLVMType(f.Signature.Results().At(0).Type())
if err != nil {
return nil, err
}
} else {
results := make([]llvm.Type, 0, f.Signature.Results().Len())
for i := 0; i < f.Signature.Results().Len(); i++ {
typ, err := c.getLLVMType(f.Signature.Results().At(i).Type())
if err != nil {
return nil, err
}
results = append(results, typ)
}
retType = c.ctx.StructType(results, false)
}
var paramTypes []llvm.Type
for _, param := range f.Params {
paramType, err := c.getLLVMType(param.Type())
if err != nil {
return nil, err
}
paramTypeFragments := c.expandFormalParamType(paramType)
paramTypes = append(paramTypes, paramTypeFragments...)
}
// Add an extra parameter as the function context. This context is used in
// closures and bound methods, but should be optimized away when not used.
if !f.IsExported() {
paramTypes = append(paramTypes, c.i8ptrType) // context
paramTypes = append(paramTypes, c.i8ptrType) // parent coroutine
}
fnType := llvm.FunctionType(retType, paramTypes, false)
name := f.LinkName()
frame.fn.LLVMFn = c.mod.NamedFunction(name)
if frame.fn.LLVMFn.IsNil() {
frame.fn.LLVMFn = llvm.AddFunction(c.mod, name, fnType)
}
return frame, nil
}
func (c *Compiler) attachDebugInfo(f *ir.Function) (llvm.Metadata, error) {
pos := c.ir.Program.Fset.Position(f.Syntax().Pos())
return c.attachDebugInfoRaw(f, f.LLVMFn, "", pos.Filename, pos.Line)
}
func (c *Compiler) attachDebugInfoRaw(f *ir.Function, llvmFn llvm.Value, suffix, filename string, line int) (llvm.Metadata, error) {
if _, ok := c.difiles[filename]; !ok {
dir, file := filepath.Split(filename)
if dir != "" {
dir = dir[:len(dir)-1]
}
c.difiles[filename] = c.dibuilder.CreateFile(file, dir)
}
// Debug info for this function.
diparams := make([]llvm.Metadata, 0, len(f.Params))
for _, param := range f.Params {
ditype, err := c.getDIType(param.Type())
if err != nil {
return llvm.Metadata{}, err
}
diparams = append(diparams, ditype)
}
diFuncType := c.dibuilder.CreateSubroutineType(llvm.DISubroutineType{
File: c.difiles[filename],
Parameters: diparams,
Flags: 0, // ?
})
difunc := c.dibuilder.CreateFunction(c.difiles[filename], llvm.DIFunction{
Name: f.RelString(nil) + suffix,
LinkageName: f.LinkName() + suffix,
File: c.difiles[filename],
Line: line,
Type: diFuncType,
LocalToUnit: true,
IsDefinition: true,
ScopeLine: 0,
Flags: llvm.FlagPrototyped,
Optimized: true,
})
llvmFn.SetSubprogram(difunc)
return difunc, nil
}
func (c *Compiler) parseFunc(frame *Frame) error {
if c.DumpSSA {
fmt.Printf("\nfunc %s:\n", frame.fn.Function)
}
if !frame.fn.IsExported() {
frame.fn.LLVMFn.SetLinkage(llvm.InternalLinkage)
frame.fn.LLVMFn.SetUnnamedAddr(true)
}
if frame.fn.IsInterrupt() && strings.HasPrefix(c.Triple, "avr") {
frame.fn.LLVMFn.SetFunctionCallConv(85) // CallingConv::AVR_SIGNAL
}
// Add debug info, if needed.
if c.Debug {
if frame.fn.Synthetic == "package initializer" {
// Package initializers have no debug info. Create some fake debug
// info to at least have *something*.
difunc, err := c.attachDebugInfoRaw(frame.fn, frame.fn.LLVMFn, "", "", 0)
if err != nil {
return err
}
frame.difunc = difunc
} else if frame.fn.Syntax() != nil {
// Create debug info file if needed.
difunc, err := c.attachDebugInfo(frame.fn)
if err != nil {
return err
}
frame.difunc = difunc
}
pos := c.ir.Program.Fset.Position(frame.fn.Pos())
c.builder.SetCurrentDebugLocation(uint(pos.Line), uint(pos.Column), frame.difunc, llvm.Metadata{})
}
// Pre-create all basic blocks in the function.
for _, block := range frame.fn.DomPreorder() {
llvmBlock := c.ctx.AddBasicBlock(frame.fn.LLVMFn, block.Comment)
frame.blockEntries[block] = llvmBlock
frame.blockExits[block] = llvmBlock
}
entryBlock := frame.blockEntries[frame.fn.Blocks[0]]
c.builder.SetInsertPointAtEnd(entryBlock)
// Load function parameters
llvmParamIndex := 0
for i, param := range frame.fn.Params {
llvmType, err := c.getLLVMType(param.Type())
if err != nil {
return err
}
fields := make([]llvm.Value, 0, 1)
for range c.expandFormalParamType(llvmType) {
fields = append(fields, frame.fn.LLVMFn.Param(llvmParamIndex))
llvmParamIndex++
}
frame.locals[param] = c.collapseFormalParam(llvmType, fields)
// Add debug information to this parameter (if available)
if c.Debug && frame.fn.Syntax() != nil {
pos := c.ir.Program.Fset.Position(frame.fn.Syntax().Pos())
dityp, err := c.getDIType(param.Type())
if err != nil {
return err
}
c.dibuilder.CreateParameterVariable(frame.difunc, llvm.DIParameterVariable{
Name: param.Name(),
File: c.difiles[pos.Filename],
Line: pos.Line,
Type: dityp,
AlwaysPreserve: true,
ArgNo: i + 1,
})
// TODO: set the value of this parameter.
}
}
// Load free variables from the context. This is a closure (or bound
// method).
var context llvm.Value
if !frame.fn.IsExported() {
parentHandle := frame.fn.LLVMFn.LastParam()
parentHandle.SetName("parentHandle")
context = llvm.PrevParam(parentHandle)
context.SetName("context")
}
if len(frame.fn.FreeVars) != 0 {
// Determine the context type. It's a struct containing all variables.
freeVarTypes := make([]llvm.Type, 0, len(frame.fn.FreeVars))
for _, freeVar := range frame.fn.FreeVars {
typ, err := c.getLLVMType(freeVar.Type())
if err != nil {
return err
}
freeVarTypes = append(freeVarTypes, typ)
}
contextType := c.ctx.StructType(freeVarTypes, false)
// Get a correctly-typed pointer to the context.
contextAlloc := llvm.Value{}
if c.targetData.TypeAllocSize(contextType) <= c.targetData.TypeAllocSize(c.i8ptrType) {
// Context stored directly in pointer. Load it using an alloca.
contextRawAlloc := c.builder.CreateAlloca(llvm.PointerType(c.i8ptrType, 0), "context.raw.alloc")
contextRawValue := c.builder.CreateBitCast(context, llvm.PointerType(c.i8ptrType, 0), "context.raw.value")
c.builder.CreateStore(contextRawValue, contextRawAlloc)
contextAlloc = c.builder.CreateBitCast(contextRawAlloc, llvm.PointerType(contextType, 0), "context.alloc")
} else {
// Context stored in the heap. Bitcast the passed-in pointer to the
// correct pointer type.
contextAlloc = c.builder.CreateBitCast(context, llvm.PointerType(contextType, 0), "context.raw.ptr")
}
// Load each free variable from the context.
// A free variable is always a pointer when this is a closure, but it
// can be another type when it is a wrapper for a bound method (these
// wrappers are generated by the ssa package).
for i, freeVar := range frame.fn.FreeVars {
indices := []llvm.Value{
llvm.ConstInt(c.ctx.Int32Type(), 0, false),
llvm.ConstInt(c.ctx.Int32Type(), uint64(i), false),
}
gep := c.builder.CreateInBoundsGEP(contextAlloc, indices, "")
frame.locals[freeVar] = c.builder.CreateLoad(gep, "")
}
}
if frame.fn.Recover != nil {
// This function has deferred function calls. Set some things up for
// them.
c.deferInitFunc(frame)
}
// Fill blocks with instructions.
for _, block := range frame.fn.DomPreorder() {
if c.DumpSSA {
fmt.Printf("%d: %s:\n", block.Index, block.Comment)
}
c.builder.SetInsertPointAtEnd(frame.blockEntries[block])
frame.currentBlock = block
for _, instr := range block.Instrs {
if _, ok := instr.(*ssa.DebugRef); ok {
continue
}
if c.DumpSSA {
if val, ok := instr.(ssa.Value); ok && val.Name() != "" {
fmt.Printf("\t%s = %s\n", val.Name(), val.String())
} else {
fmt.Printf("\t%s\n", instr.String())
}
}
err := c.parseInstr(frame, instr)
if err != nil {
return err
}
}
if frame.fn.Name() == "init" && len(block.Instrs) == 0 {
c.builder.CreateRetVoid()
}
}
// Resolve phi nodes
for _, phi := range frame.phis {
block := phi.ssa.Block()
for i, edge := range phi.ssa.Edges {
llvmVal, err := c.parseExpr(frame, edge)
if err != nil {
return err
}
llvmBlock := frame.blockExits[block.Preds[i]]
phi.llvm.AddIncoming([]llvm.Value{llvmVal}, []llvm.BasicBlock{llvmBlock})
}
}
return nil
}
func (c *Compiler) parseInstr(frame *Frame, instr ssa.Instruction) error {
if c.Debug {
pos := c.ir.Program.Fset.Position(instr.Pos())
c.builder.SetCurrentDebugLocation(uint(pos.Line), uint(pos.Column), frame.difunc, llvm.Metadata{})
}
switch instr := instr.(type) {
case ssa.Value:
value, err := c.parseExpr(frame, instr)
frame.locals[instr] = value
return err
case *ssa.DebugRef:
return nil // ignore
case *ssa.Defer:
return c.emitDefer(frame, instr)
case *ssa.Go:
if instr.Call.IsInvoke() {
return c.makeError(instr.Pos(), "todo: go on method receiver")
}
callee := instr.Call.StaticCallee()
if callee == nil {
return c.makeError(instr.Pos(), "todo: go on non-direct function (function pointer, etc.)")
}
calleeFn := c.ir.GetFunction(callee)
// Mark this function as a 'go' invocation and break invalid
// interprocedural optimizations. For example, heap-to-stack
// transformations are not sound as goroutines can outlive their parent.
calleeType := calleeFn.LLVMFn.Type()
calleeValue := c.builder.CreateBitCast(calleeFn.LLVMFn, c.i8ptrType, "")
calleeValue = c.createRuntimeCall("makeGoroutine", []llvm.Value{calleeValue}, "")
calleeValue = c.builder.CreateBitCast(calleeValue, calleeType, "")
// Get all function parameters to pass to the goroutine.
var params []llvm.Value
for _, param := range instr.Call.Args {
val, err := c.parseExpr(frame, param)
if err != nil {
return err
}
params = append(params, val)
}
if !calleeFn.IsExported() {
params = append(params, llvm.Undef(c.i8ptrType)) // context parameter
params = append(params, llvm.Undef(c.i8ptrType)) // parent coroutine handle
}
c.createCall(calleeValue, params, "")
return nil
case *ssa.If:
cond, err := c.parseExpr(frame, instr.Cond)
if err != nil {
return err
}
block := instr.Block()
blockThen := frame.blockEntries[block.Succs[0]]
blockElse := frame.blockEntries[block.Succs[1]]
c.builder.CreateCondBr(cond, blockThen, blockElse)
return nil
case *ssa.Jump:
blockJump := frame.blockEntries[instr.Block().Succs[0]]
c.builder.CreateBr(blockJump)
return nil
case *ssa.MapUpdate:
m, err := c.parseExpr(frame, instr.Map)
if err != nil {
return err
}
key, err := c.parseExpr(frame, instr.Key)
if err != nil {
return err
}
value, err := c.parseExpr(frame, instr.Value)
if err != nil {
return err
}
mapType := instr.Map.Type().Underlying().(*types.Map)
return c.emitMapUpdate(mapType.Key(), m, key, value, instr.Pos())
case *ssa.Panic:
value, err := c.parseExpr(frame, instr.X)
if err != nil {
return err
}
c.createRuntimeCall("_panic", []llvm.Value{value}, "")
c.builder.CreateUnreachable()
return nil
case *ssa.Return:
if len(instr.Results) == 0 {
c.builder.CreateRetVoid()
return nil
} else if len(instr.Results) == 1 {
val, err := c.parseExpr(frame, instr.Results[0])
if err != nil {
return err
}
c.builder.CreateRet(val)
return nil
} else {
// Multiple return values. Put them all in a struct.
retVal, err := c.getZeroValue(frame.fn.LLVMFn.Type().ElementType().ReturnType())
if err != nil {
return err
}
for i, result := range instr.Results {
val, err := c.parseExpr(frame, result)
if err != nil {
return err
}
retVal = c.builder.CreateInsertValue(retVal, val, i, "")
}
c.builder.CreateRet(retVal)
return nil
}
case *ssa.RunDefers:
return c.emitRunDefers(frame)
case *ssa.Send:
return c.emitChanSend(frame, instr)
case *ssa.Store:
llvmAddr, err := c.parseExpr(frame, instr.Addr)
if err != nil {
return err
}
llvmVal, err := c.parseExpr(frame, instr.Val)
if err != nil {
return err
}
if c.targetData.TypeAllocSize(llvmVal.Type()) == 0 {
// nothing to store
return nil
}
store := c.builder.CreateStore(llvmVal, llvmAddr)
valType := instr.Addr.Type().Underlying().(*types.Pointer).Elem()
if c.ir.IsVolatile(valType) {
// Volatile store, for memory-mapped registers.
store.SetVolatile(true)
}
return nil
default:
return c.makeError(instr.Pos(), "unknown instruction: "+instr.String())
}
}
func (c *Compiler) parseBuiltin(frame *Frame, args []ssa.Value, callName string, pos token.Pos) (llvm.Value, error) {
switch callName {
case "append":
src, err := c.parseExpr(frame, args[0])
if err != nil {
return llvm.Value{}, err
}
elems, err := c.parseExpr(frame, args[1])
if err != nil {
return llvm.Value{}, err
}
srcBuf := c.builder.CreateExtractValue(src, 0, "append.srcBuf")
srcPtr := c.builder.CreateBitCast(srcBuf, c.i8ptrType, "append.srcPtr")
srcLen := c.builder.CreateExtractValue(src, 1, "append.srcLen")
srcCap := c.builder.CreateExtractValue(src, 2, "append.srcCap")
elemsBuf := c.builder.CreateExtractValue(elems, 0, "append.elemsBuf")
elemsPtr := c.builder.CreateBitCast(elemsBuf, c.i8ptrType, "append.srcPtr")
elemsLen := c.builder.CreateExtractValue(elems, 1, "append.elemsLen")
elemType := srcBuf.Type().ElementType()
elemSize := llvm.ConstInt(c.uintptrType, c.targetData.TypeAllocSize(elemType), false)
result := c.createRuntimeCall("sliceAppend", []llvm.Value{srcPtr, elemsPtr, srcLen, srcCap, elemsLen, elemSize}, "append.new")
newPtr := c.builder.CreateExtractValue(result, 0, "append.newPtr")
newBuf := c.builder.CreateBitCast(newPtr, srcBuf.Type(), "append.newBuf")
newLen := c.builder.CreateExtractValue(result, 1, "append.newLen")
newCap := c.builder.CreateExtractValue(result, 2, "append.newCap")
newSlice := llvm.Undef(src.Type())
newSlice = c.builder.CreateInsertValue(newSlice, newBuf, 0, "")
newSlice = c.builder.CreateInsertValue(newSlice, newLen, 1, "")
newSlice = c.builder.CreateInsertValue(newSlice, newCap, 2, "")
return newSlice, nil
case "cap":
value, err := c.parseExpr(frame, args[0])
if err != nil {
return llvm.Value{}, err
}
var llvmCap llvm.Value
switch args[0].Type().(type) {
case *types.Chan:
// Channel. Buffered channels haven't been implemented yet so always
// return 0.
llvmCap = llvm.ConstInt(c.intType, 0, false)
case *types.Slice:
llvmCap = c.builder.CreateExtractValue(value, 2, "cap")
default:
return llvm.Value{}, c.makeError(pos, "todo: cap: unknown type")
}
if c.targetData.TypeAllocSize(llvmCap.Type()) < c.targetData.TypeAllocSize(c.intType) {
llvmCap = c.builder.CreateZExt(llvmCap, c.intType, "len.int")
}
return llvmCap, nil
case "close":
return llvm.Value{}, c.emitChanClose(frame, args[0])
case "complex":
r, err := c.parseExpr(frame, args[0])
if err != nil {
return llvm.Value{}, err
}
i, err := c.parseExpr(frame, args[1])
if err != nil {
return llvm.Value{}, err
}
t := args[0].Type().Underlying().(*types.Basic)
var cplx llvm.Value
switch t.Kind() {
case types.Float32:
cplx = llvm.Undef(c.ctx.StructType([]llvm.Type{c.ctx.FloatType(), c.ctx.FloatType()}, false))
case types.Float64:
cplx = llvm.Undef(c.ctx.StructType([]llvm.Type{c.ctx.DoubleType(), c.ctx.DoubleType()}, false))
default:
return llvm.Value{}, c.makeError(pos, "unsupported type in complex builtin: "+t.String())
}
cplx = c.builder.CreateInsertValue(cplx, r, 0, "")
cplx = c.builder.CreateInsertValue(cplx, i, 1, "")
return cplx, nil
case "copy":
dst, err := c.parseExpr(frame, args[0])
if err != nil {
return llvm.Value{}, err
}
src, err := c.parseExpr(frame, args[1])
if err != nil {
return llvm.Value{}, err
}
dstLen := c.builder.CreateExtractValue(dst, 1, "copy.dstLen")
srcLen := c.builder.CreateExtractValue(src, 1, "copy.srcLen")
dstBuf := c.builder.CreateExtractValue(dst, 0, "copy.dstArray")
srcBuf := c.builder.CreateExtractValue(src, 0, "copy.srcArray")
elemType := dstBuf.Type().ElementType()
dstBuf = c.builder.CreateBitCast(dstBuf, c.i8ptrType, "copy.dstPtr")
srcBuf = c.builder.CreateBitCast(srcBuf, c.i8ptrType, "copy.srcPtr")
elemSize := llvm.ConstInt(c.uintptrType, c.targetData.TypeAllocSize(elemType), false)
return c.createRuntimeCall("sliceCopy", []llvm.Value{dstBuf, srcBuf, dstLen, srcLen, elemSize}, "copy.n"), nil
case "delete":
m, err := c.parseExpr(frame, args[0])
if err != nil {
return llvm.Value{}, err
}
key, err := c.parseExpr(frame, args[1])
if err != nil {
return llvm.Value{}, err
}
return llvm.Value{}, c.emitMapDelete(args[1].Type(), m, key, pos)
case "imag":
cplx, err := c.parseExpr(frame, args[0])
if err != nil {
return llvm.Value{}, err
}
return c.builder.CreateExtractValue(cplx, 1, "imag"), nil
case "len":
value, err := c.parseExpr(frame, args[0])
if err != nil {
return llvm.Value{}, err
}
var llvmLen llvm.Value
switch args[0].Type().Underlying().(type) {
case *types.Basic, *types.Slice:
// string or slice
llvmLen = c.builder.CreateExtractValue(value, 1, "len")
case *types.Chan:
// Channel. Buffered channels haven't been implemented yet so always
// return 0.
llvmLen = llvm.ConstInt(c.intType, 0, false)
case *types.Map:
llvmLen = c.createRuntimeCall("hashmapLen", []llvm.Value{value}, "len")
default:
return llvm.Value{}, c.makeError(pos, "todo: len: unknown type")
}
if c.targetData.TypeAllocSize(llvmLen.Type()) < c.targetData.TypeAllocSize(c.intType) {
llvmLen = c.builder.CreateZExt(llvmLen, c.intType, "len.int")
}
return llvmLen, nil
case "print", "println":
for i, arg := range args {
if i >= 1 && callName == "println" {
c.createRuntimeCall("printspace", nil, "")
}
value, err := c.parseExpr(frame, arg)
if err != nil {
return llvm.Value{}, err
}
typ := arg.Type().Underlying()
switch typ := typ.(type) {
case *types.Basic:
switch typ.Kind() {
case types.String, types.UntypedString:
c.createRuntimeCall("printstring", []llvm.Value{value}, "")
case types.Uintptr:
c.createRuntimeCall("printptr", []llvm.Value{value}, "")
case types.UnsafePointer:
ptrValue := c.builder.CreatePtrToInt(value, c.uintptrType, "")
c.createRuntimeCall("printptr", []llvm.Value{ptrValue}, "")
default:
// runtime.print{int,uint}{8,16,32,64}
if typ.Info()&types.IsInteger != 0 {
name := "print"
if typ.Info()&types.IsUnsigned != 0 {
name += "uint"
} else {
name += "int"
}
name += strconv.FormatUint(c.targetData.TypeAllocSize(value.Type())*8, 10)
c.createRuntimeCall(name, []llvm.Value{value}, "")
} else if typ.Kind() == types.Bool {
c.createRuntimeCall("printbool", []llvm.Value{value}, "")
} else if typ.Kind() == types.Float32 {
c.createRuntimeCall("printfloat32", []llvm.Value{value}, "")
} else if typ.Kind() == types.Float64 {
c.createRuntimeCall("printfloat64", []llvm.Value{value}, "")
} else if typ.Kind() == types.Complex64 {
c.createRuntimeCall("printcomplex64", []llvm.Value{value}, "")
} else if typ.Kind() == types.Complex128 {
c.createRuntimeCall("printcomplex128", []llvm.Value{value}, "")
} else {
return llvm.Value{}, c.makeError(pos, "unknown basic arg type: "+typ.String())
}
}
case *types.Interface:
c.createRuntimeCall("printitf", []llvm.Value{value}, "")
case *types.Map:
c.createRuntimeCall("printmap", []llvm.Value{value}, "")
case *types.Pointer:
ptrValue := c.builder.CreatePtrToInt(value, c.uintptrType, "")
c.createRuntimeCall("printptr", []llvm.Value{ptrValue}, "")
default:
return llvm.Value{}, c.makeError(pos, "unknown arg type: "+typ.String())
}
}
if callName == "println" {
c.createRuntimeCall("printnl", nil, "")
}
return llvm.Value{}, nil // print() or println() returns void
case "real":
cplx, err := c.parseExpr(frame, args[0])
if err != nil {
return llvm.Value{}, err
}
return c.builder.CreateExtractValue(cplx, 0, "real"), nil
case "recover":
return c.createRuntimeCall("_recover", nil, ""), nil
case "ssa:wrapnilchk":
// TODO: do an actual nil check?
return c.parseExpr(frame, args[0])
default:
return llvm.Value{}, c.makeError(pos, "todo: builtin: "+callName)
}
}
func (c *Compiler) parseFunctionCall(frame *Frame, args []ssa.Value, llvmFn, context llvm.Value, exported bool) (llvm.Value, error) {
var params []llvm.Value
for _, param := range args {
val, err := c.parseExpr(frame, param)
if err != nil {
return llvm.Value{}, err
}
params = append(params, val)
}
if !exported {
// This function takes a context parameter.
// Add it to the end of the parameter list.
params = append(params, context)
// Parent coroutine handle.
params = append(params, llvm.Undef(c.i8ptrType))
}
return c.createCall(llvmFn, params, ""), nil
}
func (c *Compiler) parseCall(frame *Frame, instr *ssa.CallCommon) (llvm.Value, error) {
if instr.IsInvoke() {
fnCast, args, err := c.getInvokeCall(frame, instr)
if err != nil {
return llvm.Value{}, err
}
return c.createCall(fnCast, args, ""), nil
}
// Try to call the function directly for trivially static calls.
if fn := instr.StaticCallee(); fn != nil {
switch fn.RelString(nil) {
case "device/arm.ReadRegister":
return c.emitReadRegister(instr.Args)
case "device/arm.Asm", "device/avr.Asm":
return c.emitAsm(instr.Args)
case "device/arm.AsmFull", "device/avr.AsmFull":
return c.emitAsmFull(frame, instr)
case "device/arm.SVCall0", "device/arm.SVCall1", "device/arm.SVCall2", "device/arm.SVCall3", "device/arm.SVCall4":
return c.emitSVCall(frame, instr.Args)
case "syscall.Syscall", "syscall.Syscall6", "syscall.Syscall9":
return c.emitSyscall(frame, instr)
}
targetFunc := c.ir.GetFunction(fn)
if targetFunc.LLVMFn.IsNil() {
return llvm.Value{}, c.makeError(instr.Pos(), "undefined function: "+targetFunc.LinkName())
}
var context llvm.Value
switch value := instr.Value.(type) {
case *ssa.Function:
// Regular function call. No context is necessary.
context = llvm.Undef(c.i8ptrType)
case *ssa.MakeClosure:
// A call on a func value, but the callee is trivial to find. For
// example: immediately applied functions.
funcValue, err := c.parseExpr(frame, value)
if err != nil {
return llvm.Value{}, err
}
context = c.extractFuncContext(funcValue)
default:
panic("StaticCallee returned an unexpected value")
}
return c.parseFunctionCall(frame, instr.Args, targetFunc.LLVMFn, context, targetFunc.IsExported())
}
// Builtin or function pointer.
switch call := instr.Value.(type) {
case *ssa.Builtin:
return c.parseBuiltin(frame, instr.Args, call.Name(), instr.Pos())
default: // function pointer
value, err := c.parseExpr(frame, instr.Value)
if err != nil {
return llvm.Value{}, err
}
// This is a func value, which cannot be called directly. We have to
// extract the function pointer and context first from the func value.
funcPtr, context, err := c.decodeFuncValue(value, instr.Value.Type().(*types.Signature))
if err != nil {
return llvm.Value{}, err
}
c.emitNilCheck(frame, funcPtr, "fpcall")
return c.parseFunctionCall(frame, instr.Args, funcPtr, context, false)
}
}
func (c *Compiler) parseExpr(frame *Frame, expr ssa.Value) (llvm.Value, error) {
if value, ok := frame.locals[expr]; ok {
// Value is a local variable that has already been computed.
if value.IsNil() {
return llvm.Value{}, c.makeError(expr.Pos(), "undefined local var (from cgo?)")
}
return value, nil
}
switch expr := expr.(type) {
case *ssa.Alloc:
typ, err := c.getLLVMType(expr.Type().Underlying().(*types.Pointer).Elem())
if err != nil {
return llvm.Value{}, err
}
var buf llvm.Value
if expr.Heap {
size := c.targetData.TypeAllocSize(typ)
// Calculate ^uintptr(0)
maxSize := llvm.ConstNot(llvm.ConstInt(c.uintptrType, 0, false)).ZExtValue()
if size > maxSize {
// Size would be truncated if truncated to uintptr.
return llvm.Value{}, c.makeError(expr.Pos(), fmt.Sprintf("value is too big (%v bytes)", size))
}
// TODO: escape analysis
sizeValue := llvm.ConstInt(c.uintptrType, size, false)
buf = c.createRuntimeCall("alloc", []llvm.Value{sizeValue}, expr.Comment)
buf = c.builder.CreateBitCast(buf, llvm.PointerType(typ, 0), "")
} else {
buf = c.builder.CreateAlloca(typ, expr.Comment)
if c.targetData.TypeAllocSize(typ) != 0 {
zero, err := c.getZeroValue(typ)
if err != nil {
return llvm.Value{}, err
}
c.builder.CreateStore(zero, buf) // zero-initialize var
}
}
return buf, nil
case *ssa.BinOp:
x, err := c.parseExpr(frame, expr.X)
if err != nil {
return llvm.Value{}, err
}
y, err := c.parseExpr(frame, expr.Y)
if err != nil {
return llvm.Value{}, err
}
return c.parseBinOp(expr.Op, expr.X.Type(), x, y, expr.Pos())
case *ssa.Call:
// Passing the current task here to the subroutine. It is only used when
// the subroutine is blocking.
return c.parseCall(frame, expr.Common())
case *ssa.ChangeInterface:
// Do not change between interface types: always use the underlying
// (concrete) type in the type number of the interface. Every method
// call on an interface will do a lookup which method to call.
// This is different from how the official Go compiler works, because of
// heap allocation and because it's easier to implement, see:
// https://research.swtch.com/interfaces
return c.parseExpr(frame, expr.X)
case *ssa.ChangeType:
// This instruction changes the type, but the underlying value remains
// the same. This is often a no-op, but sometimes we have to change the
// LLVM type as well.
x, err := c.parseExpr(frame, expr.X)
if err != nil {
return llvm.Value{}, err
}
llvmType, err := c.getLLVMType(expr.Type())
if err != nil {
return llvm.Value{}, err
}
if x.Type() == llvmType {
// Different Go type but same LLVM type (for example, named int).
// This is the common case.
return x, nil
}
// Figure out what kind of type we need to cast.
switch llvmType.TypeKind() {
case llvm.StructTypeKind:
// Unfortunately, we can't just bitcast structs. We have to
// actually create a new struct of the correct type and insert the
// values from the previous struct in there.
value := llvm.Undef(llvmType)
for i := 0; i < llvmType.StructElementTypesCount(); i++ {
field := c.builder.CreateExtractValue(x, i, "changetype.field")
value = c.builder.CreateInsertValue(value, field, i, "changetype.struct")
}
return value, nil
case llvm.PointerTypeKind:
// This can happen with pointers to structs. This case is easy:
// simply bitcast the pointer to the destination type.
return c.builder.CreateBitCast(x, llvmType, "changetype.pointer"), nil
default:
return llvm.Value{}, errors.New("todo: unknown ChangeType type: " + expr.X.Type().String())
}
case *ssa.Const:
return c.parseConst(frame.fn.LinkName(), expr)
case *ssa.Convert:
x, err := c.parseExpr(frame, expr.X)
if err != nil {
return llvm.Value{}, err
}
return c.parseConvert(expr.X.Type(), expr.Type(), x, expr.Pos())
case *ssa.Extract:
value, err := c.parseExpr(frame, expr.Tuple)
if err != nil {
return llvm.Value{}, err
}
result := c.builder.CreateExtractValue(value, expr.Index, "")
return result, nil
case *ssa.Field:
value, err := c.parseExpr(frame, expr.X)
if err != nil {
return llvm.Value{}, err
}
if s := expr.X.Type().Underlying().(*types.Struct); s.NumFields() > 2 && s.Field(0).Name() == "C union" {
// Extract a field from a CGo union.
// This could be done directly, but as this is a very infrequent
// operation it's much easier to bitcast it through an alloca.
resultType, err := c.getLLVMType(expr.Type())
if err != nil {
return llvm.Value{}, err
}
alloca := c.builder.CreateAlloca(value.Type(), "")
c.builder.CreateStore(value, alloca)
bitcast := c.builder.CreateBitCast(alloca, llvm.PointerType(resultType, 0), "")
return c.builder.CreateLoad(bitcast, ""), nil
}
result := c.builder.CreateExtractValue(value, expr.Field, "")
return result, nil
case *ssa.FieldAddr:
val, err := c.parseExpr(frame, expr.X)
if err != nil {
return llvm.Value{}, err
}
// Check for nil pointer before calculating the address, from the spec:
// > For an operand x of type T, the address operation &x generates a
// > pointer of type *T to x. [...] If the evaluation of x would cause a
// > run-time panic, then the evaluation of &x does too.
c.emitNilCheck(frame, val, "gep")
if s := expr.X.Type().(*types.Pointer).Elem().Underlying().(*types.Struct); s.NumFields() > 2 && s.Field(0).Name() == "C union" {
// This is not a regular struct but actually an union.
// That simplifies things, as we can just bitcast the pointer to the
// right type.
ptrType, err := c.getLLVMType(expr.Type())
if err != nil {
return llvm.Value{}, nil
}
return c.builder.CreateBitCast(val, ptrType, ""), nil
} else {
// Do a GEP on the pointer to get the field address.
indices := []llvm.Value{
llvm.ConstInt(c.ctx.Int32Type(), 0, false),
llvm.ConstInt(c.ctx.Int32Type(), uint64(expr.Field), false),
}
return c.builder.CreateGEP(val, indices, ""), nil
}
case *ssa.Function:
fn := c.ir.GetFunction(expr)
if fn.IsExported() {
return llvm.Value{}, c.makeError(expr.Pos(), "cannot use an exported function as value")
}
return c.createFuncValue(fn.LLVMFn, llvm.Undef(c.i8ptrType), fn.Signature)
case *ssa.Global:
value := c.ir.GetGlobal(expr).LLVMGlobal
if value.IsNil() {
return llvm.Value{}, c.makeError(expr.Pos(), "global not found: "+c.ir.GetGlobal(expr).LinkName())
}
return value, nil
case *ssa.Index:
array, err := c.parseExpr(frame, expr.X)
if err != nil {
return llvm.Value{}, err
}
index, err := c.parseExpr(frame, expr.Index)
if err != nil {
return llvm.Value{}, err
}
// Check bounds.
arrayLen := expr.X.Type().(*types.Array).Len()
arrayLenLLVM := llvm.ConstInt(c.uintptrType, uint64(arrayLen), false)
c.emitLookupBoundsCheck(frame, arrayLenLLVM, index, expr.Index.Type())
// Can't load directly from array (as index is non-constant), so have to
// do it using an alloca+gep+load.
alloca := c.builder.CreateAlloca(array.Type(), "index.alloca")
c.builder.CreateStore(array, alloca)
zero := llvm.ConstInt(c.ctx.Int32Type(), 0, false)
ptr := c.builder.CreateGEP(alloca, []llvm.Value{zero, index}, "index.gep")
return c.builder.CreateLoad(ptr, "index.load"), nil
case *ssa.IndexAddr:
val, err := c.parseExpr(frame, expr.X)
if err != nil {
return llvm.Value{}, err
}
index, err := c.parseExpr(frame, expr.Index)
if err != nil {
return llvm.Value{}, err
}
// Get buffer pointer and length
var bufptr, buflen llvm.Value
switch ptrTyp := expr.X.Type().Underlying().(type) {
case *types.Pointer:
typ := expr.X.Type().Underlying().(*types.Pointer).Elem().Underlying()
switch typ := typ.(type) {
case *types.Array:
bufptr = val
buflen = llvm.ConstInt(c.uintptrType, uint64(typ.Len()), false)
// Check for nil pointer before calculating the address, from
// the spec:
// > For an operand x of type T, the address operation &x
// > generates a pointer of type *T to x. [...] If the
// > evaluation of x would cause a run-time panic, then the
// > evaluation of &x does too.
c.emitNilCheck(frame, bufptr, "gep")
default:
return llvm.Value{}, c.makeError(expr.Pos(), "todo: indexaddr: "+typ.String())
}
case *types.Slice:
bufptr = c.builder.CreateExtractValue(val, 0, "indexaddr.ptr")
buflen = c.builder.CreateExtractValue(val, 1, "indexaddr.len")
default:
return llvm.Value{}, c.makeError(expr.Pos(), "todo: indexaddr: "+ptrTyp.String())
}
// Bounds check.
c.emitLookupBoundsCheck(frame, buflen, index, expr.Index.Type())
switch expr.X.Type().Underlying().(type) {
case *types.Pointer:
indices := []llvm.Value{
llvm.ConstInt(c.ctx.Int32Type(), 0, false),
index,
}
return c.builder.CreateGEP(bufptr, indices, ""), nil
case *types.Slice:
return c.builder.CreateGEP(bufptr, []llvm.Value{index}, ""), nil
default:
panic("unreachable")
}
case *ssa.Lookup:
value, err := c.parseExpr(frame, expr.X)
if err != nil {
return llvm.Value{}, nil
}
index, err := c.parseExpr(frame, expr.Index)
if err != nil {
return llvm.Value{}, nil
}
switch xType := expr.X.Type().Underlying().(type) {
case *types.Basic:
// Value type must be a string, which is a basic type.
if xType.Info()&types.IsString == 0 {
panic("lookup on non-string?")
}
// Bounds check.
length := c.builder.CreateExtractValue(value, 1, "len")
c.emitLookupBoundsCheck(frame, length, index, expr.Index.Type())
// Lookup byte
buf := c.builder.CreateExtractValue(value, 0, "")
bufPtr := c.builder.CreateGEP(buf, []llvm.Value{index}, "")
return c.builder.CreateLoad(bufPtr, ""), nil
case *types.Map:
valueType := expr.Type()
if expr.CommaOk {
valueType = valueType.(*types.Tuple).At(0).Type()
}
return c.emitMapLookup(xType.Key(), valueType, value, index, expr.CommaOk, expr.Pos())
default:
panic("unknown lookup type: " + expr.String())
}
case *ssa.MakeChan:
return c.emitMakeChan(expr)
case *ssa.MakeClosure:
return c.parseMakeClosure(frame, expr)
case *ssa.MakeInterface:
val, err := c.parseExpr(frame, expr.X)
if err != nil {
return llvm.Value{}, err
}
return c.parseMakeInterface(val, expr.X.Type(), expr.Pos())
case *ssa.MakeMap:
mapType := expr.Type().Underlying().(*types.Map)
llvmKeyType, err := c.getLLVMType(mapType.Key().Underlying())
if err != nil {
return llvm.Value{}, err
}
llvmValueType, err := c.getLLVMType(mapType.Elem().Underlying())
if err != nil {
return llvm.Value{}, err
}
keySize := c.targetData.TypeAllocSize(llvmKeyType)
valueSize := c.targetData.TypeAllocSize(llvmValueType)
llvmKeySize := llvm.ConstInt(c.ctx.Int8Type(), keySize, false)
llvmValueSize := llvm.ConstInt(c.ctx.Int8Type(), valueSize, false)
hashmap := c.createRuntimeCall("hashmapMake", []llvm.Value{llvmKeySize, llvmValueSize}, "")
return hashmap, nil
case *ssa.MakeSlice:
sliceLen, err := c.parseExpr(frame, expr.Len)
if err != nil {
return llvm.Value{}, nil
}
sliceCap, err := c.parseExpr(frame, expr.Cap)
if err != nil {
return llvm.Value{}, nil
}
sliceType := expr.Type().Underlying().(*types.Slice)
llvmElemType, err := c.getLLVMType(sliceType.Elem())
if err != nil {
return llvm.Value{}, nil
}
elemSize := c.targetData.TypeAllocSize(llvmElemType)
elemSizeValue := llvm.ConstInt(c.uintptrType, elemSize, false)
// Calculate (^uintptr(0)) >> 1, which is the max value that fits in
// uintptr if uintptr were signed.
maxSize := llvm.ConstLShr(llvm.ConstNot(llvm.ConstInt(c.uintptrType, 0, false)), llvm.ConstInt(c.uintptrType, 1, false))
if elemSize > maxSize.ZExtValue() {
// This seems to be checked by the typechecker already, but let's
// check it again just to be sure.
return llvm.Value{}, c.makeError(expr.Pos(), fmt.Sprintf("slice element type is too big (%v bytes)", elemSize))
}
// Bounds checking.
c.emitSliceBoundsCheck(frame, maxSize, sliceLen, sliceCap, expr.Len.Type().(*types.Basic), expr.Cap.Type().(*types.Basic))
// Allocate the backing array.
// TODO: escape analysis
sliceCapCast, err := c.parseConvert(expr.Cap.Type(), types.Typ[types.Uintptr], sliceCap, expr.Pos())
if err != nil {
return llvm.Value{}, err
}
sliceSize := c.builder.CreateBinOp(llvm.Mul, elemSizeValue, sliceCapCast, "makeslice.cap")
slicePtr := c.createRuntimeCall("alloc", []llvm.Value{sliceSize}, "makeslice.buf")
slicePtr = c.builder.CreateBitCast(slicePtr, llvm.PointerType(llvmElemType, 0), "makeslice.array")
// Extend or truncate if necessary. This is safe as we've already done
// the bounds check.
sliceLen, err = c.parseConvert(expr.Len.Type(), types.Typ[types.Uintptr], sliceLen, expr.Pos())
if err != nil {
return llvm.Value{}, err
}
sliceCap, err = c.parseConvert(expr.Cap.Type(), types.Typ[types.Uintptr], sliceCap, expr.Pos())
if err != nil {
return llvm.Value{}, err
}
// Create the slice.
slice := c.ctx.ConstStruct([]llvm.Value{
llvm.Undef(slicePtr.Type()),
llvm.Undef(c.uintptrType),
llvm.Undef(c.uintptrType),
}, false)
slice = c.builder.CreateInsertValue(slice, slicePtr, 0, "")
slice = c.builder.CreateInsertValue(slice, sliceLen, 1, "")
slice = c.builder.CreateInsertValue(slice, sliceCap, 2, "")
return slice, nil
case *ssa.Next:
rangeVal := expr.Iter.(*ssa.Range).X
llvmRangeVal, err := c.parseExpr(frame, rangeVal)
if err != nil {
return llvm.Value{}, err
}
it, err := c.parseExpr(frame, expr.Iter)
if err != nil {
return llvm.Value{}, err
}
if expr.IsString {
return c.createRuntimeCall("stringNext", []llvm.Value{llvmRangeVal, it}, "range.next"), nil
} else { // map
llvmKeyType, err := c.getLLVMType(rangeVal.Type().Underlying().(*types.Map).Key())
if err != nil {
return llvm.Value{}, err
}
llvmValueType, err := c.getLLVMType(rangeVal.Type().Underlying().(*types.Map).Elem())
if err != nil {
return llvm.Value{}, err
}
mapKeyAlloca := c.builder.CreateAlloca(llvmKeyType, "range.key")
mapKeyPtr := c.builder.CreateBitCast(mapKeyAlloca, c.i8ptrType, "range.keyptr")
mapValueAlloca := c.builder.CreateAlloca(llvmValueType, "range.value")
mapValuePtr := c.builder.CreateBitCast(mapValueAlloca, c.i8ptrType, "range.valueptr")
ok := c.createRuntimeCall("hashmapNext", []llvm.Value{llvmRangeVal, it, mapKeyPtr, mapValuePtr}, "range.next")
tuple := llvm.Undef(c.ctx.StructType([]llvm.Type{c.ctx.Int1Type(), llvmKeyType, llvmValueType}, false))
tuple = c.builder.CreateInsertValue(tuple, ok, 0, "")
tuple = c.builder.CreateInsertValue(tuple, c.builder.CreateLoad(mapKeyAlloca, ""), 1, "")
tuple = c.builder.CreateInsertValue(tuple, c.builder.CreateLoad(mapValueAlloca, ""), 2, "")
return tuple, nil
}
case *ssa.Phi:
t, err := c.getLLVMType(expr.Type())
if err != nil {
return llvm.Value{}, err
}
phi := c.builder.CreatePHI(t, "")
frame.phis = append(frame.phis, Phi{expr, phi})
return phi, nil
case *ssa.Range:
var iteratorType llvm.Type
switch typ := expr.X.Type().Underlying().(type) {
case *types.Basic: // string
iteratorType = c.mod.GetTypeByName("runtime.stringIterator")
case *types.Map:
iteratorType = c.mod.GetTypeByName("runtime.hashmapIterator")
default:
panic("unknown type in range: " + typ.String())
}
it := c.builder.CreateAlloca(iteratorType, "range.it")
zero, err := c.getZeroValue(iteratorType)
if err != nil {
return llvm.Value{}, nil
}
c.builder.CreateStore(zero, it)
return it, nil
case *ssa.Select:
if len(expr.States) == 0 {
// Shortcuts for some simple selects.
llvmType, err := c.getLLVMType(expr.Type())
if err != nil {
return llvm.Value{}, err
}
if expr.Blocking {
// Blocks forever:
// select {}
c.createRuntimeCall("deadlockStub", nil, "")
return llvm.Undef(llvmType), nil
} else {
// No-op:
// select {
// default:
// }
retval := llvm.Undef(llvmType)
retval = c.builder.CreateInsertValue(retval, llvm.ConstInt(c.intType, 0xffffffffffffffff, true), 0, "")
return retval, nil // {-1, false}
}
}
return llvm.Value{}, c.makeError(expr.Pos(), "unimplemented: "+expr.String())
case *ssa.Slice:
if expr.Max != nil {
return llvm.Value{}, c.makeError(expr.Pos(), "todo: full slice expressions (with max): "+expr.Type().String())
}
value, err := c.parseExpr(frame, expr.X)
if err != nil {
return llvm.Value{}, err
}
var lowType, highType *types.Basic
var low, high llvm.Value
if expr.Low != nil {
lowType = expr.Low.Type().Underlying().(*types.Basic)
low, err = c.parseExpr(frame, expr.Low)
if err != nil {
return llvm.Value{}, nil
}
if low.Type().IntTypeWidth() < c.uintptrType.IntTypeWidth() {
if lowType.Info()&types.IsUnsigned != 0 {
low = c.builder.CreateZExt(low, c.uintptrType, "")
} else {
low = c.builder.CreateSExt(low, c.uintptrType, "")
}
}
} else {
lowType = types.Typ[types.Uintptr]
low = llvm.ConstInt(c.uintptrType, 0, false)
}
if expr.High != nil {
highType = expr.High.Type().Underlying().(*types.Basic)
high, err = c.parseExpr(frame, expr.High)
if err != nil {
return llvm.Value{}, nil
}
if high.Type().IntTypeWidth() < c.uintptrType.IntTypeWidth() {
if highType.Info()&types.IsUnsigned != 0 {
high = c.builder.CreateZExt(high, c.uintptrType, "")
} else {
high = c.builder.CreateSExt(high, c.uintptrType, "")
}
}
} else {
highType = types.Typ[types.Uintptr]
}
switch typ := expr.X.Type().Underlying().(type) {
case *types.Pointer: // pointer to array
// slice an array
length := typ.Elem().Underlying().(*types.Array).Len()
llvmLen := llvm.ConstInt(c.uintptrType, uint64(length), false)
if high.IsNil() {
high = llvmLen
}
indices := []llvm.Value{
llvm.ConstInt(c.ctx.Int32Type(), 0, false),
low,
}
c.emitSliceBoundsCheck(frame, llvmLen, low, high, lowType, highType)
// Truncate ints bigger than uintptr. This is after the bounds
// check so it's safe.
if c.targetData.TypeAllocSize(high.Type()) > c.targetData.TypeAllocSize(c.uintptrType) {
high = c.builder.CreateTrunc(high, c.uintptrType, "")
}
if c.targetData.TypeAllocSize(low.Type()) > c.targetData.TypeAllocSize(c.uintptrType) {
low = c.builder.CreateTrunc(low, c.uintptrType, "")
}
sliceLen := c.builder.CreateSub(high, low, "slice.len")
slicePtr := c.builder.CreateGEP(value, indices, "slice.ptr")
sliceCap := c.builder.CreateSub(llvmLen, low, "slice.cap")
slice := c.ctx.ConstStruct([]llvm.Value{
llvm.Undef(slicePtr.Type()),
llvm.Undef(c.uintptrType),
llvm.Undef(c.uintptrType),
}, false)
slice = c.builder.CreateInsertValue(slice, slicePtr, 0, "")
slice = c.builder.CreateInsertValue(slice, sliceLen, 1, "")
slice = c.builder.CreateInsertValue(slice, sliceCap, 2, "")
return slice, nil
case *types.Slice:
// slice a slice
oldPtr := c.builder.CreateExtractValue(value, 0, "")
oldLen := c.builder.CreateExtractValue(value, 1, "")
oldCap := c.builder.CreateExtractValue(value, 2, "")
if high.IsNil() {
high = oldLen
}
c.emitSliceBoundsCheck(frame, oldCap, low, high, lowType, highType)
// Truncate ints bigger than uintptr. This is after the bounds
// check so it's safe.
if c.targetData.TypeAllocSize(low.Type()) > c.targetData.TypeAllocSize(c.uintptrType) {
low = c.builder.CreateTrunc(low, c.uintptrType, "")
}
if c.targetData.TypeAllocSize(high.Type()) > c.targetData.TypeAllocSize(c.uintptrType) {
high = c.builder.CreateTrunc(high, c.uintptrType, "")
}
newPtr := c.builder.CreateGEP(oldPtr, []llvm.Value{low}, "")
newLen := c.builder.CreateSub(high, low, "")
newCap := c.builder.CreateSub(oldCap, low, "")
slice := c.ctx.ConstStruct([]llvm.Value{
llvm.Undef(newPtr.Type()),
llvm.Undef(c.uintptrType),
llvm.Undef(c.uintptrType),
}, false)
slice = c.builder.CreateInsertValue(slice, newPtr, 0, "")
slice = c.builder.CreateInsertValue(slice, newLen, 1, "")
slice = c.builder.CreateInsertValue(slice, newCap, 2, "")
return slice, nil
case *types.Basic:
if typ.Info()&types.IsString == 0 {
return llvm.Value{}, c.makeError(expr.Pos(), "unknown slice type: "+typ.String())
}
// slice a string
oldPtr := c.builder.CreateExtractValue(value, 0, "")
oldLen := c.builder.CreateExtractValue(value, 1, "")
if high.IsNil() {
high = oldLen
}
c.emitSliceBoundsCheck(frame, oldLen, low, high, lowType, highType)
// Truncate ints bigger than uintptr. This is after the bounds
// check so it's safe.
if c.targetData.TypeAllocSize(low.Type()) > c.targetData.TypeAllocSize(c.uintptrType) {
low = c.builder.CreateTrunc(low, c.uintptrType, "")
}
if c.targetData.TypeAllocSize(high.Type()) > c.targetData.TypeAllocSize(c.uintptrType) {
high = c.builder.CreateTrunc(high, c.uintptrType, "")
}
newPtr := c.builder.CreateGEP(oldPtr, []llvm.Value{low}, "")
newLen := c.builder.CreateSub(high, low, "")
str, err := c.getZeroValue(c.mod.GetTypeByName("runtime._string"))
if err != nil {
return llvm.Value{}, err
}
str = c.builder.CreateInsertValue(str, newPtr, 0, "")
str = c.builder.CreateInsertValue(str, newLen, 1, "")
return str, nil
default:
return llvm.Value{}, c.makeError(expr.Pos(), "unknown slice type: "+typ.String())
}
case *ssa.TypeAssert:
return c.parseTypeAssert(frame, expr)
case *ssa.UnOp:
return c.parseUnOp(frame, expr)
default:
return llvm.Value{}, c.makeError(expr.Pos(), "todo: unknown expression: "+expr.String())
}
}
func (c *Compiler) parseBinOp(op token.Token, typ types.Type, x, y llvm.Value, pos token.Pos) (llvm.Value, error) {
switch typ := typ.Underlying().(type) {
case *types.Basic:
if typ.Info()&types.IsInteger != 0 {
// Operations on integers
signed := typ.Info()&types.IsUnsigned == 0
switch op {
case token.ADD: // +
return c.builder.CreateAdd(x, y, ""), nil
case token.SUB: // -
return c.builder.CreateSub(x, y, ""), nil
case token.MUL: // *
return c.builder.CreateMul(x, y, ""), nil
case token.QUO: // /
if signed {
return c.builder.CreateSDiv(x, y, ""), nil
} else {
return c.builder.CreateUDiv(x, y, ""), nil
}
case token.REM: // %
if signed {
return c.builder.CreateSRem(x, y, ""), nil
} else {
return c.builder.CreateURem(x, y, ""), nil
}
case token.AND: // &
return c.builder.CreateAnd(x, y, ""), nil
case token.OR: // |
return c.builder.CreateOr(x, y, ""), nil
case token.XOR: // ^
return c.builder.CreateXor(x, y, ""), nil
case token.SHL, token.SHR:
sizeX := c.targetData.TypeAllocSize(x.Type())
sizeY := c.targetData.TypeAllocSize(y.Type())
if sizeX > sizeY {
// x and y must have equal sizes, make Y bigger in this case.
// y is unsigned, this has been checked by the Go type checker.
y = c.builder.CreateZExt(y, x.Type(), "")
} else if sizeX < sizeY {
// What about shifting more than the integer width?
// I'm not entirely sure what the Go spec is on that, but as
// Intel CPUs have undefined behavior when shifting more
// than the integer width I'm assuming it is also undefined
// in Go.
y = c.builder.CreateTrunc(y, x.Type(), "")
}
switch op {
case token.SHL: // <<
return c.builder.CreateShl(x, y, ""), nil
case token.SHR: // >>
if signed {
return c.builder.CreateAShr(x, y, ""), nil
} else {
return c.builder.CreateLShr(x, y, ""), nil
}
default:
panic("unreachable")
}
case token.EQL: // ==
return c.builder.CreateICmp(llvm.IntEQ, x, y, ""), nil
case token.NEQ: // !=
return c.builder.CreateICmp(llvm.IntNE, x, y, ""), nil
case token.AND_NOT: // &^
// Go specific. Calculate "and not" with x & (~y)
inv := c.builder.CreateNot(y, "") // ~y
return c.builder.CreateAnd(x, inv, ""), nil
case token.LSS: // <
if signed {
return c.builder.CreateICmp(llvm.IntSLT, x, y, ""), nil
} else {
return c.builder.CreateICmp(llvm.IntULT, x, y, ""), nil
}
case token.LEQ: // <=
if signed {
return c.builder.CreateICmp(llvm.IntSLE, x, y, ""), nil
} else {
return c.builder.CreateICmp(llvm.IntULE, x, y, ""), nil
}
case token.GTR: // >
if signed {
return c.builder.CreateICmp(llvm.IntSGT, x, y, ""), nil
} else {
return c.builder.CreateICmp(llvm.IntUGT, x, y, ""), nil
}
case token.GEQ: // >=
if signed {
return c.builder.CreateICmp(llvm.IntSGE, x, y, ""), nil
} else {
return c.builder.CreateICmp(llvm.IntUGE, x, y, ""), nil
}
default:
panic("binop on integer: " + op.String())
}
} else if typ.Info()&types.IsFloat != 0 {
// Operations on floats
switch op {
case token.ADD: // +
return c.builder.CreateFAdd(x, y, ""), nil
case token.SUB: // -
return c.builder.CreateFSub(x, y, ""), nil
case token.MUL: // *
return c.builder.CreateFMul(x, y, ""), nil
case token.QUO: // /
return c.builder.CreateFDiv(x, y, ""), nil
case token.EQL: // ==
return c.builder.CreateFCmp(llvm.FloatUEQ, x, y, ""), nil
case token.NEQ: // !=
return c.builder.CreateFCmp(llvm.FloatUNE, x, y, ""), nil
case token.LSS: // <
return c.builder.CreateFCmp(llvm.FloatULT, x, y, ""), nil
case token.LEQ: // <=
return c.builder.CreateFCmp(llvm.FloatULE, x, y, ""), nil
case token.GTR: // >
return c.builder.CreateFCmp(llvm.FloatUGT, x, y, ""), nil
case token.GEQ: // >=
return c.builder.CreateFCmp(llvm.FloatUGE, x, y, ""), nil
default:
panic("binop on float: " + op.String())
}
} else if typ.Info()&types.IsComplex != 0 {
r1 := c.builder.CreateExtractValue(x, 0, "r1")
r2 := c.builder.CreateExtractValue(y, 0, "r2")
i1 := c.builder.CreateExtractValue(x, 1, "i1")
i2 := c.builder.CreateExtractValue(y, 1, "i2")
switch op {
case token.EQL: // ==
req := c.builder.CreateFCmp(llvm.FloatOEQ, r1, r2, "")
ieq := c.builder.CreateFCmp(llvm.FloatOEQ, i1, i2, "")
return c.builder.CreateAnd(req, ieq, ""), nil
case token.NEQ: // !=
req := c.builder.CreateFCmp(llvm.FloatOEQ, r1, r2, "")
ieq := c.builder.CreateFCmp(llvm.FloatOEQ, i1, i2, "")
neq := c.builder.CreateAnd(req, ieq, "")
return c.builder.CreateNot(neq, ""), nil
default:
return llvm.Value{}, c.makeError(pos, "todo: binop on complex number: "+op.String())
}
} else if typ.Info()&types.IsBoolean != 0 {
// Operations on booleans
switch op {
case token.EQL: // ==
return c.builder.CreateICmp(llvm.IntEQ, x, y, ""), nil
case token.NEQ: // !=
return c.builder.CreateICmp(llvm.IntNE, x, y, ""), nil
default:
panic("binop on bool: " + op.String())
}
} else if typ.Kind() == types.UnsafePointer {
// Operations on pointers
switch op {
case token.EQL: // ==
return c.builder.CreateICmp(llvm.IntEQ, x, y, ""), nil
case token.NEQ: // !=
return c.builder.CreateICmp(llvm.IntNE, x, y, ""), nil
default:
panic("binop on pointer: " + op.String())
}
} else if typ.Info()&types.IsString != 0 {
// Operations on strings
switch op {
case token.ADD: // +
return c.createRuntimeCall("stringConcat", []llvm.Value{x, y}, ""), nil
case token.EQL: // ==
return c.createRuntimeCall("stringEqual", []llvm.Value{x, y}, ""), nil
case token.NEQ: // !=
result := c.createRuntimeCall("stringEqual", []llvm.Value{x, y}, "")
return c.builder.CreateNot(result, ""), nil
case token.LSS: // <
return c.createRuntimeCall("stringLess", []llvm.Value{x, y}, ""), nil
case token.LEQ: // <=
result := c.createRuntimeCall("stringLess", []llvm.Value{y, x}, "")
return c.builder.CreateNot(result, ""), nil
case token.GTR: // >
result := c.createRuntimeCall("stringLess", []llvm.Value{x, y}, "")
return c.builder.CreateNot(result, ""), nil
case token.GEQ: // >=
return c.createRuntimeCall("stringLess", []llvm.Value{y, x}, ""), nil
default:
panic("binop on string: " + op.String())
}
} else {
return llvm.Value{}, c.makeError(pos, "todo: unknown basic type in binop: "+typ.String())
}
case *types.Signature:
// Get raw scalars from the function value and compare those.
// Function values may be implemented in multiple ways, but they all
// have some way of getting a scalar value identifying the function.
// This is safe: function pointers are generally not comparable
// against each other, only against nil. So one of these has to be nil.
x = c.extractFuncScalar(x)
y = c.extractFuncScalar(y)
switch op {
case token.EQL: // ==
return c.builder.CreateICmp(llvm.IntEQ, x, y, ""), nil
case token.NEQ: // !=
return c.builder.CreateICmp(llvm.IntNE, x, y, ""), nil
default:
return llvm.Value{}, c.makeError(pos, "binop on signature: "+op.String())
}
case *types.Interface:
switch op {
case token.EQL, token.NEQ: // ==, !=
result := c.createRuntimeCall("interfaceEqual", []llvm.Value{x, y}, "")
if op == token.NEQ {
result = c.builder.CreateNot(result, "")
}
return result, nil
default:
return llvm.Value{}, c.makeError(pos, "binop on interface: "+op.String())
}
case *types.Map, *types.Pointer:
// Maps are in general not comparable, but can be compared against nil
// (which is a nil pointer). This means they can be trivially compared
// by treating them as a pointer.
switch op {
case token.EQL: // ==
return c.builder.CreateICmp(llvm.IntEQ, x, y, ""), nil
case token.NEQ: // !=
return c.builder.CreateICmp(llvm.IntNE, x, y, ""), nil
default:
return llvm.Value{}, c.makeError(pos, "todo: binop on pointer: "+op.String())
}
case *types.Slice:
// Slices are in general not comparable, but can be compared against
// nil. Assume at least one of them is nil to make the code easier.
xPtr := c.builder.CreateExtractValue(x, 0, "")
yPtr := c.builder.CreateExtractValue(y, 0, "")
switch op {
case token.EQL: // ==
return c.builder.CreateICmp(llvm.IntEQ, xPtr, yPtr, ""), nil
case token.NEQ: // !=
return c.builder.CreateICmp(llvm.IntNE, xPtr, yPtr, ""), nil
default:
return llvm.Value{}, c.makeError(pos, "todo: binop on slice: "+op.String())
}
case *types.Array:
// Compare each array element and combine the result. From the spec:
// Array values are comparable if values of the array element type
// are comparable. Two array values are equal if their corresponding
// elements are equal.
result := llvm.ConstInt(c.ctx.Int1Type(), 1, true)
for i := 0; i < int(typ.Len()); i++ {
xField := c.builder.CreateExtractValue(x, i, "")
yField := c.builder.CreateExtractValue(y, i, "")
fieldEqual, err := c.parseBinOp(token.EQL, typ.Elem(), xField, yField, pos)
if err != nil {
return llvm.Value{}, err
}
result = c.builder.CreateAnd(result, fieldEqual, "")
}
switch op {
case token.EQL: // ==
return result, nil
case token.NEQ: // !=
return c.builder.CreateNot(result, ""), nil
default:
return llvm.Value{}, c.makeError(pos, "unknown: binop on struct: "+op.String())
}
case *types.Struct:
// Compare each struct field and combine the result. From the spec:
// Struct values are comparable if all their fields are comparable.
// Two struct values are equal if their corresponding non-blank
// fields are equal.
result := llvm.ConstInt(c.ctx.Int1Type(), 1, true)
for i := 0; i < typ.NumFields(); i++ {
if typ.Field(i).Name() == "_" {
// skip blank fields
continue
}
fieldType := typ.Field(i).Type()
xField := c.builder.CreateExtractValue(x, i, "")
yField := c.builder.CreateExtractValue(y, i, "")
fieldEqual, err := c.parseBinOp(token.EQL, fieldType, xField, yField, pos)
if err != nil {
return llvm.Value{}, err
}
result = c.builder.CreateAnd(result, fieldEqual, "")
}
switch op {
case token.EQL: // ==
return result, nil
case token.NEQ: // !=
return c.builder.CreateNot(result, ""), nil
default:
return llvm.Value{}, c.makeError(pos, "unknown: binop on struct: "+op.String())
}
default:
return llvm.Value{}, c.makeError(pos, "todo: binop type: "+typ.String())
}
}
func (c *Compiler) parseConst(prefix string, expr *ssa.Const) (llvm.Value, error) {
switch typ := expr.Type().Underlying().(type) {
case *types.Basic:
llvmType, err := c.getLLVMType(typ)
if err != nil {
return llvm.Value{}, err
}
if typ.Info()&types.IsBoolean != 0 {
b := constant.BoolVal(expr.Value)
n := uint64(0)
if b {
n = 1
}
return llvm.ConstInt(llvmType, n, false), nil
} else if typ.Info()&types.IsString != 0 {
str := constant.StringVal(expr.Value)
strLen := llvm.ConstInt(c.uintptrType, uint64(len(str)), false)
objname := prefix + "$string"
global := llvm.AddGlobal(c.mod, llvm.ArrayType(c.ctx.Int8Type(), len(str)), objname)
global.SetInitializer(c.ctx.ConstString(str, false))
global.SetLinkage(llvm.InternalLinkage)
global.SetGlobalConstant(true)
global.SetUnnamedAddr(true)
zero := llvm.ConstInt(c.ctx.Int32Type(), 0, false)
strPtr := c.builder.CreateInBoundsGEP(global, []llvm.Value{zero, zero}, "")
strObj := llvm.ConstNamedStruct(c.mod.GetTypeByName("runtime._string"), []llvm.Value{strPtr, strLen})
return strObj, nil
} else if typ.Kind() == types.UnsafePointer {
if !expr.IsNil() {
value, _ := constant.Uint64Val(expr.Value)
return llvm.ConstIntToPtr(llvm.ConstInt(c.uintptrType, value, false), c.i8ptrType), nil
}
return llvm.ConstNull(c.i8ptrType), nil
} else if typ.Info()&types.IsUnsigned != 0 {
n, _ := constant.Uint64Val(expr.Value)
return llvm.ConstInt(llvmType, n, false), nil
} else if typ.Info()&types.IsInteger != 0 { // signed
n, _ := constant.Int64Val(expr.Value)
return llvm.ConstInt(llvmType, uint64(n), true), nil
} else if typ.Info()&types.IsFloat != 0 {
n, _ := constant.Float64Val(expr.Value)
return llvm.ConstFloat(llvmType, n), nil
} else if typ.Kind() == types.Complex64 {
r, err := c.parseConst(prefix, ssa.NewConst(constant.Real(expr.Value), types.Typ[types.Float32]))
if err != nil {
return llvm.Value{}, err
}
i, err := c.parseConst(prefix, ssa.NewConst(constant.Imag(expr.Value), types.Typ[types.Float32]))
if err != nil {
return llvm.Value{}, err
}
cplx := llvm.Undef(c.ctx.StructType([]llvm.Type{c.ctx.FloatType(), c.ctx.FloatType()}, false))
cplx = c.builder.CreateInsertValue(cplx, r, 0, "")
cplx = c.builder.CreateInsertValue(cplx, i, 1, "")
return cplx, nil
} else if typ.Kind() == types.Complex128 {
r, err := c.parseConst(prefix, ssa.NewConst(constant.Real(expr.Value), types.Typ[types.Float64]))
if err != nil {
return llvm.Value{}, err
}
i, err := c.parseConst(prefix, ssa.NewConst(constant.Imag(expr.Value), types.Typ[types.Float64]))
if err != nil {
return llvm.Value{}, err
}
cplx := llvm.Undef(c.ctx.StructType([]llvm.Type{c.ctx.DoubleType(), c.ctx.DoubleType()}, false))
cplx = c.builder.CreateInsertValue(cplx, r, 0, "")
cplx = c.builder.CreateInsertValue(cplx, i, 1, "")
return cplx, nil
} else {
return llvm.Value{}, errors.New("todo: unknown constant: " + expr.String())
}
case *types.Chan:
sig, err := c.getLLVMType(expr.Type())
if err != nil {
return llvm.Value{}, err
}
return c.getZeroValue(sig)
case *types.Signature:
if expr.Value != nil {
return llvm.Value{}, errors.New("non-nil signature constant")
}
sig, err := c.getLLVMType(expr.Type())
if err != nil {
return llvm.Value{}, err
}
return c.getZeroValue(sig)
case *types.Interface:
if expr.Value != nil {
return llvm.Value{}, errors.New("non-nil interface constant")
}
// Create a generic nil interface with no dynamic type (typecode=0).
fields := []llvm.Value{
llvm.ConstInt(c.uintptrType, 0, false),
llvm.ConstPointerNull(c.i8ptrType),
}
itf := llvm.ConstNamedStruct(c.mod.GetTypeByName("runtime._interface"), fields)
return itf, nil
case *types.Pointer:
if expr.Value != nil {
return llvm.Value{}, errors.New("non-nil pointer constant")
}
llvmType, err := c.getLLVMType(typ)
if err != nil {
return llvm.Value{}, err
}
return llvm.ConstPointerNull(llvmType), nil
case *types.Slice:
if expr.Value != nil {
return llvm.Value{}, errors.New("non-nil slice constant")
}
elemType, err := c.getLLVMType(typ.Elem())
if err != nil {
return llvm.Value{}, err
}
llvmPtr := llvm.ConstPointerNull(llvm.PointerType(elemType, 0))
llvmLen := llvm.ConstInt(c.uintptrType, 0, false)
slice := c.ctx.ConstStruct([]llvm.Value{
llvmPtr, // backing array
llvmLen, // len
llvmLen, // cap
}, false)
return slice, nil
case *types.Map:
if !expr.IsNil() {
// I believe this is not allowed by the Go spec.
panic("non-nil map constant")
}
llvmType, err := c.getLLVMType(typ)
if err != nil {
return llvm.Value{}, err
}
return c.getZeroValue(llvmType)
default:
return llvm.Value{}, errors.New("todo: unknown constant: " + expr.String())
}
}
func (c *Compiler) parseConvert(typeFrom, typeTo types.Type, value llvm.Value, pos token.Pos) (llvm.Value, error) {
llvmTypeFrom := value.Type()
llvmTypeTo, err := c.getLLVMType(typeTo)
if err != nil {
return llvm.Value{}, err
}
// Conversion between unsafe.Pointer and uintptr.
isPtrFrom := isPointer(typeFrom.Underlying())
isPtrTo := isPointer(typeTo.Underlying())
if isPtrFrom && !isPtrTo {
return c.builder.CreatePtrToInt(value, llvmTypeTo, ""), nil
} else if !isPtrFrom && isPtrTo {
if !value.IsABinaryOperator().IsNil() && value.InstructionOpcode() == llvm.Add {
// This is probably a pattern like the following:
// unsafe.Pointer(uintptr(ptr) + index)
// Used in functions like memmove etc. for lack of pointer
// arithmetic. Convert it to real pointer arithmatic here.
ptr := value.Operand(0)
index := value.Operand(1)
if !index.IsAPtrToIntInst().IsNil() {
// Swap if necessary, if ptr and index are reversed.
ptr, index = index, ptr
}
if !ptr.IsAPtrToIntInst().IsNil() {
origptr := ptr.Operand(0)
if origptr.Type() == c.i8ptrType {
// This pointer can be calculated from the original
// ptrtoint instruction with a GEP. The leftover inttoptr
// instruction is trivial to optimize away.
return c.builder.CreateGEP(origptr, []llvm.Value{index}, ""), nil
}
}
}
return c.builder.CreateIntToPtr(value, llvmTypeTo, ""), nil
}
// Conversion between pointers and unsafe.Pointer.
if isPtrFrom && isPtrTo {
return c.builder.CreateBitCast(value, llvmTypeTo, ""), nil
}
switch typeTo := typeTo.Underlying().(type) {
case *types.Basic:
sizeFrom := c.targetData.TypeAllocSize(llvmTypeFrom)
if typeTo.Info()&types.IsString != 0 {
switch typeFrom := typeFrom.Underlying().(type) {
case *types.Basic:
// Assume a Unicode code point, as that is the only possible
// value here.
// Cast to an i32 value as expected by
// runtime.stringFromUnicode.
if sizeFrom > 4 {
value = c.builder.CreateTrunc(value, c.ctx.Int32Type(), "")
} else if sizeFrom < 4 && typeTo.Info()&types.IsUnsigned != 0 {
value = c.builder.CreateZExt(value, c.ctx.Int32Type(), "")
} else if sizeFrom < 4 {
value = c.builder.CreateSExt(value, c.ctx.Int32Type(), "")
}
return c.createRuntimeCall("stringFromUnicode", []llvm.Value{value}, ""), nil
case *types.Slice:
switch typeFrom.Elem().(*types.Basic).Kind() {
case types.Byte:
return c.createRuntimeCall("stringFromBytes", []llvm.Value{value}, ""), nil
default:
return llvm.Value{}, c.makeError(pos, "todo: convert to string: "+typeFrom.String())
}
default:
return llvm.Value{}, c.makeError(pos, "todo: convert to string: "+typeFrom.String())
}
}
typeFrom := typeFrom.Underlying().(*types.Basic)
sizeTo := c.targetData.TypeAllocSize(llvmTypeTo)
if typeFrom.Info()&types.IsInteger != 0 && typeTo.Info()&types.IsInteger != 0 {
// Conversion between two integers.
if sizeFrom > sizeTo {
return c.builder.CreateTrunc(value, llvmTypeTo, ""), nil
} else if typeFrom.Info()&types.IsUnsigned != 0 { // if unsigned
return c.builder.CreateZExt(value, llvmTypeTo, ""), nil
} else { // if signed
return c.builder.CreateSExt(value, llvmTypeTo, ""), nil
}
}
if typeFrom.Info()&types.IsFloat != 0 && typeTo.Info()&types.IsFloat != 0 {
// Conversion between two floats.
if sizeFrom > sizeTo {
return c.builder.CreateFPTrunc(value, llvmTypeTo, ""), nil
} else if sizeFrom < sizeTo {
return c.builder.CreateFPExt(value, llvmTypeTo, ""), nil
} else {
return value, nil
}
}
if typeFrom.Info()&types.IsFloat != 0 && typeTo.Info()&types.IsInteger != 0 {
// Conversion from float to int.
if typeTo.Info()&types.IsUnsigned != 0 { // if unsigned
return c.builder.CreateFPToUI(value, llvmTypeTo, ""), nil
} else { // if signed
return c.builder.CreateFPToSI(value, llvmTypeTo, ""), nil
}
}
if typeFrom.Info()&types.IsInteger != 0 && typeTo.Info()&types.IsFloat != 0 {
// Conversion from int to float.
if typeFrom.Info()&types.IsUnsigned != 0 { // if unsigned
return c.builder.CreateUIToFP(value, llvmTypeTo, ""), nil
} else { // if signed
return c.builder.CreateSIToFP(value, llvmTypeTo, ""), nil
}
}
if typeFrom.Kind() == types.Complex128 && typeTo.Kind() == types.Complex64 {
// Conversion from complex128 to complex64.
r := c.builder.CreateExtractValue(value, 0, "real.f64")
i := c.builder.CreateExtractValue(value, 1, "imag.f64")
r = c.builder.CreateFPTrunc(r, c.ctx.FloatType(), "real.f32")
i = c.builder.CreateFPTrunc(i, c.ctx.FloatType(), "imag.f32")
cplx := llvm.Undef(c.ctx.StructType([]llvm.Type{c.ctx.FloatType(), c.ctx.FloatType()}, false))
cplx = c.builder.CreateInsertValue(cplx, r, 0, "")
cplx = c.builder.CreateInsertValue(cplx, i, 1, "")
return cplx, nil
}
if typeFrom.Kind() == types.Complex64 && typeTo.Kind() == types.Complex128 {
// Conversion from complex64 to complex128.
r := c.builder.CreateExtractValue(value, 0, "real.f32")
i := c.builder.CreateExtractValue(value, 1, "imag.f32")
r = c.builder.CreateFPExt(r, c.ctx.DoubleType(), "real.f64")
i = c.builder.CreateFPExt(i, c.ctx.DoubleType(), "imag.f64")
cplx := llvm.Undef(c.ctx.StructType([]llvm.Type{c.ctx.DoubleType(), c.ctx.DoubleType()}, false))
cplx = c.builder.CreateInsertValue(cplx, r, 0, "")
cplx = c.builder.CreateInsertValue(cplx, i, 1, "")
return cplx, nil
}
return llvm.Value{}, c.makeError(pos, "todo: convert: basic non-integer type: "+typeFrom.String()+" -> "+typeTo.String())
case *types.Slice:
if basic, ok := typeFrom.(*types.Basic); !ok || basic.Info()&types.IsString == 0 {
panic("can only convert from a string to a slice")
}
elemType := typeTo.Elem().Underlying().(*types.Basic) // must be byte or rune
switch elemType.Kind() {
case types.Byte:
return c.createRuntimeCall("stringToBytes", []llvm.Value{value}, ""), nil
default:
return llvm.Value{}, c.makeError(pos, "todo: convert from string: "+elemType.String())
}
default:
return llvm.Value{}, c.makeError(pos, "todo: convert "+typeTo.String()+" <- "+typeFrom.String())
}
}
func (c *Compiler) parseUnOp(frame *Frame, unop *ssa.UnOp) (llvm.Value, error) {
x, err := c.parseExpr(frame, unop.X)
if err != nil {
return llvm.Value{}, err
}
switch unop.Op {
case token.NOT: // !x
return c.builder.CreateNot(x, ""), nil
case token.SUB: // -x
if typ, ok := unop.X.Type().Underlying().(*types.Basic); ok {
if typ.Info()&types.IsInteger != 0 {
return c.builder.CreateSub(llvm.ConstInt(x.Type(), 0, false), x, ""), nil
} else if typ.Info()&types.IsFloat != 0 {
return c.builder.CreateFSub(llvm.ConstFloat(x.Type(), 0.0), x, ""), nil
} else {
return llvm.Value{}, c.makeError(unop.Pos(), "todo: unknown basic type for negate: "+typ.String())
}
} else {
return llvm.Value{}, c.makeError(unop.Pos(), "todo: unknown type for negate: "+unop.X.Type().Underlying().String())
}
case token.MUL: // *x, dereference pointer
valType := unop.X.Type().Underlying().(*types.Pointer).Elem()
if c.targetData.TypeAllocSize(x.Type().ElementType()) == 0 {
// zero-length data
return c.getZeroValue(x.Type().ElementType())
} else if strings.HasSuffix(unop.X.String(), "$funcaddr") {
// CGo function pointer. The cgo part has rewritten CGo function
// pointers as stub global variables of the form:
// var C.add unsafe.Pointer
// Instead of a load from the global, create a bitcast of the
// function pointer itself.
global := c.ir.GetGlobal(unop.X.(*ssa.Global))
name := global.LinkName()[:len(global.LinkName())-len("$funcaddr")]
fn := c.mod.NamedFunction(name)
return c.builder.CreateBitCast(fn, c.i8ptrType, ""), nil
} else {
c.emitNilCheck(frame, x, "deref")
load := c.builder.CreateLoad(x, "")
if c.ir.IsVolatile(valType) {
// Volatile load, for memory-mapped registers.
load.SetVolatile(true)
}
return load, nil
}
case token.XOR: // ^x, toggle all bits in integer
return c.builder.CreateXor(x, llvm.ConstInt(x.Type(), ^uint64(0), false), ""), nil
case token.ARROW: // <-x, receive from channel
return c.emitChanRecv(frame, unop)
default:
return llvm.Value{}, c.makeError(unop.Pos(), "todo: unknown unop")
}
}
// 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) ApplyFunctionSections() {
// Put every function in a separate section. This makes it possible for the
// linker to remove dead code (-ffunction-sections).
llvmFn := c.mod.FirstFunction()
for !llvmFn.IsNil() {
if !llvmFn.IsDeclaration() {
name := llvmFn.Name()
llvmFn.SetSection(".text." + name)
}
llvmFn = llvm.NextFunction(llvmFn)
}
}
// Turn all global constants into global variables. This works around a
// limitation on Harvard architectures (e.g. AVR), where constant and
// non-constant pointers point to a different address space.
func (c *Compiler) NonConstGlobals() {
global := c.mod.FirstGlobal()
for !global.IsNil() {
global.SetGlobalConstant(false)
global = llvm.NextGlobal(global)
}
}
// When -wasm-abi flag set to "js" (default),
// replace i64 in an external function with a stack-allocated i64*, to work
// around the lack of 64-bit integers in JavaScript (commonly used together with
// WebAssembly). Once that's resolved, this pass may be avoided.
// See also the -wasm-abi= flag
// https://github.com/WebAssembly/design/issues/1172
func (c *Compiler) ExternalInt64AsPtr() error {
int64Type := c.ctx.Int64Type()
int64PtrType := llvm.PointerType(int64Type, 0)
for fn := c.mod.FirstFunction(); !fn.IsNil(); fn = llvm.NextFunction(fn) {
if fn.Linkage() != llvm.ExternalLinkage {
// Only change externally visible functions (exports and imports).
continue
}
if strings.HasPrefix(fn.Name(), "llvm.") || strings.HasPrefix(fn.Name(), "runtime.") {
// Do not try to modify the signature of internal LLVM functions and
// assume that runtime functions are only temporarily exported for
// coroutine lowering.
continue
}
hasInt64 := false
paramTypes := []llvm.Type{}
// Check return type for 64-bit integer.
fnType := fn.Type().ElementType()
returnType := fnType.ReturnType()
if returnType == int64Type {
hasInt64 = true
paramTypes = append(paramTypes, int64PtrType)
returnType = c.ctx.VoidType()
}
// Check param types for 64-bit integers.
for param := fn.FirstParam(); !param.IsNil(); param = llvm.NextParam(param) {
if param.Type() == int64Type {
hasInt64 = true
paramTypes = append(paramTypes, int64PtrType)
} else {
paramTypes = append(paramTypes, param.Type())
}
}
if !hasInt64 {
// No i64 in the paramter list.
continue
}
// Add $i64wrapper to the real function name as it is only used
// internally.
// Add a new function with the correct signature that is exported.
name := fn.Name()
fn.SetName(name + "$i64wrap")
externalFnType := llvm.FunctionType(returnType, paramTypes, fnType.IsFunctionVarArg())
externalFn := llvm.AddFunction(c.mod, name, externalFnType)
if fn.IsDeclaration() {
// Just a declaration: the definition doesn't exist on the Go side
// so it cannot be called from external code.
// Update all users to call the external function.
// The old $i64wrapper function could be removed, but it may as well
// be left in place.
for use := fn.FirstUse(); !use.IsNil(); use = use.NextUse() {
call := use.User()
c.builder.SetInsertPointBefore(call)
callParams := []llvm.Value{}
var retvalAlloca llvm.Value
if fnType.ReturnType() == int64Type {
retvalAlloca = c.builder.CreateAlloca(int64Type, "i64asptr")
callParams = append(callParams, retvalAlloca)
}
for i := 0; i < call.OperandsCount()-1; i++ {
operand := call.Operand(i)
if operand.Type() == int64Type {
// Pass a stack-allocated pointer instead of the value
// itself.
alloca := c.builder.CreateAlloca(int64Type, "i64asptr")
c.builder.CreateStore(operand, alloca)
callParams = append(callParams, alloca)
} else {
// Unchanged parameter.
callParams = append(callParams, operand)
}
}
if fnType.ReturnType() == int64Type {
// Pass a stack-allocated pointer as the first parameter
// where the return value should be stored, instead of using
// the regular return value.
c.builder.CreateCall(externalFn, callParams, call.Name())
returnValue := c.builder.CreateLoad(retvalAlloca, "retval")
call.ReplaceAllUsesWith(returnValue)
call.EraseFromParentAsInstruction()
} else {
newCall := c.builder.CreateCall(externalFn, callParams, call.Name())
call.ReplaceAllUsesWith(newCall)
call.EraseFromParentAsInstruction()
}
}
} else {
// The function has a definition in Go. This means that it may still
// be called both Go and from external code.
// Keep existing calls with the existing convention in place (for
// better performance), but export a new wrapper function with the
// correct calling convention.
fn.SetLinkage(llvm.InternalLinkage)
fn.SetUnnamedAddr(true)
entryBlock := llvm.AddBasicBlock(externalFn, "entry")
c.builder.SetInsertPointAtEnd(entryBlock)
var callParams []llvm.Value
if fnType.ReturnType() == int64Type {
return errors.New("not yet implemented: exported function returns i64 with -wasm-abi=js; " +
"see https://tinygo.org/compiler-internals/calling-convention/")
}
for i, origParam := range fn.Params() {
paramValue := externalFn.Param(i)
if origParam.Type() == int64Type {
paramValue = c.builder.CreateLoad(paramValue, "i64")
}
callParams = append(callParams, paramValue)
}
retval := c.builder.CreateCall(fn, callParams, "")
if retval.Type().TypeKind() == llvm.VoidTypeKind {
c.builder.CreateRetVoid()
} else {
c.builder.CreateRet(retval)
}
}
}
return nil
}
// Emit object file (.o).
func (c *Compiler) EmitObject(path string) error {
llvmBuf, err := c.machine.EmitToMemoryBuffer(c.mod, llvm.ObjectFile)
if err != nil {
return err
}
return c.writeFile(llvmBuf.Bytes(), path)
}
// Emit LLVM bitcode file (.bc).
func (c *Compiler) EmitBitcode(path string) error {
data := llvm.WriteBitcodeToMemoryBuffer(c.mod).Bytes()
return c.writeFile(data, path)
}
// Emit LLVM IR source file (.ll).
func (c *Compiler) EmitText(path string) error {
data := []byte(c.mod.String())
return c.writeFile(data, path)
}
// Write the data to the file specified by path.
func (c *Compiler) writeFile(data []byte, path string) error {
// Write output to file
f, err := os.OpenFile(path, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0666)
if err != nil {
return err
}
_, err = f.Write(data)
if err != nil {
return err
}
return f.Close()
}
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