softonik/tinygo
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tinygo/compiler/compiler.go
Ayke van Laethem 6c6a43310a
compiler: fix invalid incoming block in complex typeassert flow 
A single *ssa.BasicBlock may be split in multiple LLVM basic blocks due
to typeassert instructions. This means the incoming block and outgoing
block are different. PHI nodes need to get the result from the outgoing
block, which was fixed before, but incoming branches need to branch to
the incoming block, not the outgoing block.

Branching to the outgoing block led to a LLVM verification error when
compiling the fmt package.

Originally found in (*fmt.pp).handleMethods.
2018-10-23 15:00:37 +02:00

3582 строки
124 КиБ
Go
Исходный Авторство История

package compiler
import (
"errors"
"fmt"
"go/build"
"go/constant"
"go/token"
"go/types"
"os"
"path/filepath"
"regexp"
"runtime"
"strconv"
"strings"
"github.com/aykevl/go-llvm"
"github.com/aykevl/tinygo/ir"
"go/parser"
"golang.org/x/tools/go/loader"
"golang.org/x/tools/go/ssa"
)
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)
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 {runtime.GOOS/runtime.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
uintptrType llvm.Type
lenType llvm.Type
coroIdFunc llvm.Value
coroSizeFunc llvm.Value
coroBeginFunc llvm.Value
coroSuspendFunc llvm.Value
coroEndFunc llvm.Value
coroFreeFunc llvm.Value
initFuncs []llvm.Value
deferFuncs []*ir.Function
ctxDeferFuncs []ContextDeferFunction
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
blocking bool
taskHandle llvm.Value
cleanupBlock llvm.BasicBlock
suspendBlock llvm.BasicBlock
deferPtr llvm.Value
difunc llvm.Metadata
}
type Phi struct {
ssa *ssa.Phi
llvm llvm.Value
}
// A thunk for a defer that defers calling a function pointer with context.
type ContextDeferFunction struct {
fn llvm.Value
deferStruct []llvm.Type
signature *types.Signature
}
func NewCompiler(pkgName string, config Config) (*Compiler, error) {
if config.Triple == "" {
config.Triple = llvm.DefaultTargetTriple()
}
if len(config.BuildTags) == 0 {
config.BuildTags = []string{runtime.GOOS, runtime.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, "", "", 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()
c.dibuilder = llvm.NewDIBuilder(c.mod)
// Depends on platform (32bit or 64bit), but fix it here for now.
c.intType = c.ctx.Int32Type()
c.uintptrType = c.ctx.IntType(c.targetData.PointerSize() * 8)
if c.targetData.PointerSize() < 4 {
// 16 or 8 bits target with smaller length type
c.lenType = c.uintptrType
} else {
c.lenType = c.ctx.Int32Type() // also defined as runtime.lenType
}
c.i8ptrType = llvm.PointerType(c.ctx.Int8Type(), 0)
coroIdType := llvm.FunctionType(c.ctx.TokenType(), []llvm.Type{c.ctx.Int32Type(), c.i8ptrType, c.i8ptrType, c.i8ptrType}, false)
c.coroIdFunc = llvm.AddFunction(c.mod, "llvm.coro.id", coroIdType)
coroSizeType := llvm.FunctionType(c.ctx.Int32Type(), nil, false)
c.coroSizeFunc = llvm.AddFunction(c.mod, "llvm.coro.size.i32", coroSizeType)
coroBeginType := llvm.FunctionType(c.i8ptrType, []llvm.Type{c.ctx.TokenType(), c.i8ptrType}, false)
c.coroBeginFunc = llvm.AddFunction(c.mod, "llvm.coro.begin", coroBeginType)
coroSuspendType := llvm.FunctionType(c.ctx.Int8Type(), []llvm.Type{c.ctx.TokenType(), c.ctx.Int1Type()}, false)
c.coroSuspendFunc = llvm.AddFunction(c.mod, "llvm.coro.suspend", coroSuspendType)
coroEndType := llvm.FunctionType(c.ctx.Int1Type(), []llvm.Type{c.i8ptrType, c.ctx.Int1Type()}, false)
c.coroEndFunc = llvm.AddFunction(c.mod, "llvm.coro.end", coroEndType)
coroFreeType := llvm.FunctionType(c.i8ptrType, []llvm.Type{c.ctx.TokenType(), c.i8ptrType}, false)
c.coroFreeFunc = llvm.AddFunction(c.mod, "llvm.coro.free", coroFreeType)
return c, nil
}
// Return the LLVM module. Only valid after a successful compile.
func (c *Compiler) Module() llvm.Module {
return c.mod
}
// 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 {
tripleSplit := strings.Split(c.Triple, "-")
// Prefix the GOPATH with the system GOROOT, as GOROOT is already set to
// the TinyGo root.
gopath := c.GOPATH
if gopath == "" {
gopath = runtime.GOROOT()
} else {
gopath = runtime.GOROOT() + string(filepath.ListSeparator) + gopath
}
config := loader.Config{
TypeChecker: types.Config{
Sizes: &StdSizes{
IntSize: int64(c.targetData.TypeAllocSize(c.intType)),
PtrSize: int64(c.targetData.PointerSize()),
MaxAlign: int64(c.targetData.PrefTypeAlignment(c.i8ptrType)),
},
},
Build: &build.Context{
GOARCH: tripleSplit[0],
GOOS: tripleSplit[2],
GOROOT: c.RootDir,
GOPATH: gopath,
CgoEnabled: true,
UseAllFiles: false,
Compiler: "gc", // must be one of the recognized compilers
BuildTags: append([]string{"tgo"}, c.BuildTags...),
},
ParserMode: parser.ParseComments,
}
config.Import("runtime")
if strings.HasSuffix(mainPath, ".go") {
config.CreateFromFilenames("main", mainPath)
} else {
config.Import(mainPath)
}
lprogram, err := config.Load()
if err != nil {
return err
}
c.ir = ir.NewProgram(lprogram, mainPath)
// Run some DCE and analysis passes. The results are later used by the
// compiler.
c.ir.SimpleDCE() // remove most dead code
c.ir.AnalyseCallgraph() // set up callgraph
c.ir.AnalyseInterfaceConversions() // determine which types are converted to an interface
c.ir.AnalyseFunctionPointers() // determine which function pointer signatures need context
c.ir.AnalyseBlockingRecursive() // make all parents of blocking calls blocking (transitively)
c.ir.AnalyseGoCalls() // check whether we need a scheduler
// Initialize debug information.
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. These will get an initializer when parsing "package
// initializer" functions.
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)
}
// Find and interpret package initializers.
for _, frame := range frames {
if frame.fn.Synthetic == "package initializer" {
c.initFuncs = append(c.initFuncs, frame.fn.LLVMFn)
if len(frame.fn.Blocks) != 1 {
panic("unexpected number of basic blocks in package initializer")
}
// Try to interpret as much as possible of the init() function.
// Whenever it hits an instruction that it doesn't understand, it
// bails out and leaves the rest to the compiler (so initialization
// continues at runtime).
// This should only happen when it hits a function call or the end
// of the block, ideally.
err := c.ir.Interpret(frame.fn.Blocks[0], c.DumpSSA)
if err != nil {
return err
}
err = c.parseFunc(frame)
if err != nil {
return err
}
}
}
// Set values for globals (after package initializer has been interpreted).
for _, g := range c.ir.Globals {
if g.Initializer() == nil {
continue
}
err := c.parseGlobalInitializer(g)
if err != nil {
return err
}
}
// Add definitions to declarations.
for _, frame := range frames {
if frame.fn.CName() != "" {
continue
}
if frame.fn.Blocks == nil {
continue // external function
}
var err error
if frame.fn.Synthetic == "package initializer" {
continue // already done
} else {
err = c.parseFunc(frame)
}
if err != nil {
return err
}
}
// Create deferred function wrappers.
for _, fn := range c.deferFuncs {
// This function gets a single parameter which is a pointer to a struct
// (the defer frame).
// This struct starts with the values of runtime._defer, but after that
// follow the real function parameters.
// The job of this wrapper is to extract these parameters and to call
// the real function with them.
llvmFn := c.mod.NamedFunction(fn.LinkName() + "$defer")
llvmFn.SetLinkage(llvm.InternalLinkage)
entry := c.ctx.AddBasicBlock(llvmFn, "entry")
c.builder.SetInsertPointAtEnd(entry)
deferRawPtr := llvmFn.Param(0)
// Get the real param type and cast to it.
valueTypes := []llvm.Type{llvmFn.Type(), llvm.PointerType(c.mod.GetTypeByName("runtime._defer"), 0)}
for _, param := range fn.Params {
llvmType, err := c.getLLVMType(param.Type())
if err != nil {
return err
}
valueTypes = append(valueTypes, llvmType)
}
deferFrameType := c.ctx.StructType(valueTypes, false)
deferFramePtr := c.builder.CreateBitCast(deferRawPtr, llvm.PointerType(deferFrameType, 0), "deferFrame")
// Extract the params from the struct.
forwardParams := []llvm.Value{}
zero := llvm.ConstInt(c.ctx.Int32Type(), 0, false)
for i := range fn.Params {
gep := c.builder.CreateGEP(deferFramePtr, []llvm.Value{zero, llvm.ConstInt(c.ctx.Int32Type(), uint64(i+2), false)}, "gep")
forwardParam := c.builder.CreateLoad(gep, "param")
forwardParams = append(forwardParams, forwardParam)
}
// Call real function (of which this is a wrapper).
c.createCall(fn.LLVMFn, forwardParams, "")
c.builder.CreateRetVoid()
}
// Create wrapper for deferred function pointer call.
for _, thunk := range c.ctxDeferFuncs {
// This function gets a single parameter which is a pointer to a struct
// (the defer frame).
// This struct starts with the values of runtime._defer, but after that
// follows the closure and then the real parameters.
// The job of this wrapper is to extract this closure and these
// parameters and to call the function pointer with them.
llvmFn := thunk.fn
llvmFn.SetLinkage(llvm.InternalLinkage)
entry := c.ctx.AddBasicBlock(llvmFn, "entry")
// TODO: set the debug location - perhaps the location of the rundefers
// call?
c.builder.SetInsertPointAtEnd(entry)
deferRawPtr := llvmFn.Param(0)
// Get the real param type and cast to it.
deferFrameType := c.ctx.StructType(thunk.deferStruct, false)
deferFramePtr := c.builder.CreateBitCast(deferRawPtr, llvm.PointerType(deferFrameType, 0), "defer.frame")
// Extract the params from the struct.
forwardParams := []llvm.Value{}
zero := llvm.ConstInt(c.ctx.Int32Type(), 0, false)
for i := 3; i < len(thunk.deferStruct); i++ {
gep := c.builder.CreateGEP(deferFramePtr, []llvm.Value{zero, llvm.ConstInt(c.ctx.Int32Type(), uint64(i), false)}, "")
forwardParam := c.builder.CreateLoad(gep, "param")
forwardParams = append(forwardParams, forwardParam)
}
// Extract the closure from the struct.
fpGEP := c.builder.CreateGEP(deferFramePtr, []llvm.Value{
zero,
llvm.ConstInt(c.ctx.Int32Type(), 2, false),
llvm.ConstInt(c.ctx.Int32Type(), 1, false),
}, "closure.fp.ptr")
fp := c.builder.CreateLoad(fpGEP, "closure.fp")
contextGEP := c.builder.CreateGEP(deferFramePtr, []llvm.Value{
zero,
llvm.ConstInt(c.ctx.Int32Type(), 2, false),
llvm.ConstInt(c.ctx.Int32Type(), 0, false),
}, "closure.context.ptr")
context := c.builder.CreateLoad(contextGEP, "closure.context")
forwardParams = append(forwardParams, context)
// Cast the function pointer in the closure to the correct function
// pointer type.
closureType, err := c.getLLVMType(thunk.signature)
if err != nil {
return err
}
fpType := closureType.StructElementTypes()[1]
fpCast := c.builder.CreateBitCast(fp, fpType, "closure.fp.cast")
// Call real function (of which this is a wrapper).
c.createCall(fpCast, forwardParams, "")
c.builder.CreateRetVoid()
}
// 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)
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, nil, "")
}
c.builder.CreateRetVoid()
mainWrapper := c.ir.GetFunction(c.ir.Program.ImportedPackage("runtime").Members["mainWrapper"].(*ssa.Function))
mainWrapper.LLVMFn.SetLinkage(llvm.InternalLinkage)
difunc, err = c.attachDebugInfo(mainWrapper)
if err != nil {
return err
}
pos = c.ir.Program.Fset.Position(mainWrapper.Pos())
c.builder.SetCurrentDebugLocation(uint(pos.Line), uint(pos.Column), difunc, llvm.Metadata{})
block = c.ctx.AddBasicBlock(mainWrapper.LLVMFn, "entry")
c.builder.SetInsertPointAtEnd(block)
realMain := c.mod.NamedFunction(c.ir.MainPkg().Pkg.Path() + ".main")
if c.ir.NeedsScheduler() {
coroutine := c.builder.CreateCall(realMain, []llvm.Value{llvm.ConstPointerNull(c.i8ptrType)}, "")
scheduler := c.mod.NamedFunction("runtime.scheduler")
c.builder.CreateCall(scheduler, []llvm.Value{coroutine}, "")
} else {
c.builder.CreateCall(realMain, nil, "")
}
c.builder.CreateRetVoid()
// Initialize runtime type information, for interfaces.
// See src/runtime/interface.go for more details.
dynamicTypes := c.ir.AllDynamicTypes()
numDynamicTypes := 0
for _, meta := range dynamicTypes {
numDynamicTypes += len(meta.Methods)
}
ranges := make([]llvm.Value, 0, len(dynamicTypes))
funcPointers := make([]llvm.Value, 0, numDynamicTypes)
signatures := make([]llvm.Value, 0, numDynamicTypes)
startIndex := 0
rangeType := c.mod.GetTypeByName("runtime.methodSetRange")
for _, meta := range dynamicTypes {
rangeValues := []llvm.Value{
llvm.ConstInt(c.ctx.Int16Type(), uint64(startIndex), false),
llvm.ConstInt(c.ctx.Int16Type(), uint64(len(meta.Methods)), false),
}
rangeValue := llvm.ConstNamedStruct(rangeType, rangeValues)
ranges = append(ranges, rangeValue)
methods := make([]*types.Selection, 0, len(meta.Methods))
for _, method := range meta.Methods {
methods = append(methods, method)
}
c.ir.SortMethods(methods)
for _, method := range methods {
f := c.ir.GetFunction(c.ir.Program.MethodValue(method))
if f.LLVMFn.IsNil() {
return errors.New("cannot find function: " + f.LinkName())
}
fn, err := c.wrapInterfaceInvoke(f)
if err != nil {
return err
}
fnPtr := llvm.ConstBitCast(fn, c.i8ptrType)
funcPointers = append(funcPointers, fnPtr)
signatureNum := c.ir.MethodNum(method.Obj().(*types.Func))
signature := llvm.ConstInt(c.ctx.Int16Type(), uint64(signatureNum), false)
signatures = append(signatures, signature)
}
startIndex += len(meta.Methods)
}
interfaceTypes := c.ir.AllInterfaces()
interfaceIndex := make([]llvm.Value, len(interfaceTypes))
interfaceLengths := make([]llvm.Value, len(interfaceTypes))
interfaceMethods := make([]llvm.Value, 0)
for i, itfType := range interfaceTypes {
if itfType.Type.NumMethods() > 0xff {
return errors.New("too many methods for interface " + itfType.Type.String())
}
interfaceIndex[i] = llvm.ConstInt(c.ctx.Int16Type(), uint64(i), false)
interfaceLengths[i] = llvm.ConstInt(c.ctx.Int8Type(), uint64(itfType.Type.NumMethods()), false)
funcs := make([]*types.Func, itfType.Type.NumMethods())
for i := range funcs {
funcs[i] = itfType.Type.Method(i)
}
c.ir.SortFuncs(funcs)
for _, f := range funcs {
id := llvm.ConstInt(c.ctx.Int16Type(), uint64(c.ir.MethodNum(f)), false)
interfaceMethods = append(interfaceMethods, id)
}
}
if len(ranges) >= 1<<16 {
return errors.New("method call numbers do not fit in a 16-bit integer")
}
// Replace the pre-created arrays with the generated arrays.
rangeArray := llvm.ConstArray(rangeType, ranges)
rangeArrayNewGlobal := llvm.AddGlobal(c.mod, rangeArray.Type(), "runtime.methodSetRanges.tmp")
rangeArrayNewGlobal.SetInitializer(rangeArray)
rangeArrayNewGlobal.SetLinkage(llvm.InternalLinkage)
rangeArrayOldGlobal := c.mod.NamedGlobal("runtime.methodSetRanges")
rangeArrayOldGlobal.ReplaceAllUsesWith(llvm.ConstBitCast(rangeArrayNewGlobal, rangeArrayOldGlobal.Type()))
rangeArrayOldGlobal.EraseFromParentAsGlobal()
rangeArrayNewGlobal.SetName("runtime.methodSetRanges")
funcArray := llvm.ConstArray(c.i8ptrType, funcPointers)
funcArrayNewGlobal := llvm.AddGlobal(c.mod, funcArray.Type(), "runtime.methodSetFunctions.tmp")
funcArrayNewGlobal.SetInitializer(funcArray)
funcArrayNewGlobal.SetLinkage(llvm.InternalLinkage)
funcArrayOldGlobal := c.mod.NamedGlobal("runtime.methodSetFunctions")
funcArrayOldGlobal.ReplaceAllUsesWith(llvm.ConstBitCast(funcArrayNewGlobal, funcArrayOldGlobal.Type()))
funcArrayOldGlobal.EraseFromParentAsGlobal()
funcArrayNewGlobal.SetName("runtime.methodSetFunctions")
signatureArray := llvm.ConstArray(c.ctx.Int16Type(), signatures)
signatureArrayNewGlobal := llvm.AddGlobal(c.mod, signatureArray.Type(), "runtime.methodSetSignatures.tmp")
signatureArrayNewGlobal.SetInitializer(signatureArray)
signatureArrayNewGlobal.SetLinkage(llvm.InternalLinkage)
signatureArrayOldGlobal := c.mod.NamedGlobal("runtime.methodSetSignatures")
signatureArrayOldGlobal.ReplaceAllUsesWith(llvm.ConstBitCast(signatureArrayNewGlobal, signatureArrayOldGlobal.Type()))
signatureArrayOldGlobal.EraseFromParentAsGlobal()
signatureArrayNewGlobal.SetName("runtime.methodSetSignatures")
interfaceIndexArray := llvm.ConstArray(c.ctx.Int16Type(), interfaceIndex)
interfaceIndexArrayNewGlobal := llvm.AddGlobal(c.mod, interfaceIndexArray.Type(), "runtime.interfaceIndex.tmp")
interfaceIndexArrayNewGlobal.SetInitializer(interfaceIndexArray)
interfaceIndexArrayNewGlobal.SetLinkage(llvm.InternalLinkage)
interfaceIndexArrayOldGlobal := c.mod.NamedGlobal("runtime.interfaceIndex")
interfaceIndexArrayOldGlobal.ReplaceAllUsesWith(llvm.ConstBitCast(interfaceIndexArrayNewGlobal, interfaceIndexArrayOldGlobal.Type()))
interfaceIndexArrayOldGlobal.EraseFromParentAsGlobal()
interfaceIndexArrayNewGlobal.SetName("runtime.interfaceIndex")
interfaceLengthsArray := llvm.ConstArray(c.ctx.Int8Type(), interfaceLengths)
interfaceLengthsArrayNewGlobal := llvm.AddGlobal(c.mod, interfaceLengthsArray.Type(), "runtime.interfaceLengths.tmp")
interfaceLengthsArrayNewGlobal.SetInitializer(interfaceLengthsArray)
interfaceLengthsArrayNewGlobal.SetLinkage(llvm.InternalLinkage)
interfaceLengthsArrayOldGlobal := c.mod.NamedGlobal("runtime.interfaceLengths")
interfaceLengthsArrayOldGlobal.ReplaceAllUsesWith(llvm.ConstBitCast(interfaceLengthsArrayNewGlobal, interfaceLengthsArrayOldGlobal.Type()))
interfaceLengthsArrayOldGlobal.EraseFromParentAsGlobal()
interfaceLengthsArrayNewGlobal.SetName("runtime.interfaceLengths")
interfaceMethodsArray := llvm.ConstArray(c.ctx.Int16Type(), interfaceMethods)
interfaceMethodsArrayNewGlobal := llvm.AddGlobal(c.mod, interfaceMethodsArray.Type(), "runtime.interfaceMethods.tmp")
interfaceMethodsArrayNewGlobal.SetInitializer(interfaceMethodsArray)
interfaceMethodsArrayNewGlobal.SetLinkage(llvm.InternalLinkage)
interfaceMethodsArrayOldGlobal := c.mod.NamedGlobal("runtime.interfaceMethods")
interfaceMethodsArrayOldGlobal.ReplaceAllUsesWith(llvm.ConstBitCast(interfaceMethodsArrayNewGlobal, interfaceMethodsArrayOldGlobal.Type()))
interfaceMethodsArrayOldGlobal.EraseFromParentAsGlobal()
interfaceMethodsArrayNewGlobal.SetName("runtime.interfaceMethods")
c.mod.NamedGlobal("runtime.firstTypeWithMethods").SetInitializer(llvm.ConstInt(c.ctx.Int16Type(), uint64(c.ir.FirstDynamicType()), false))
// see: https://reviews.llvm.org/D18355
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 llvm.VectorType(c.ctx.FloatType(), 2), nil
case types.Complex128:
return llvm.VectorType(c.ctx.DoubleType(), 2), 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 pointer
// return value
var err error
var returnType llvm.Type
if typ.Results().Len() == 0 {
returnType = c.ctx.VoidType()
} else if typ.Results().Len() == 1 {
returnType, err = c.getLLVMType(typ.Results().At(0).Type())
if err != nil {
return llvm.Type{}, err
}
} else {
// Multiple return values. Put them together in a struct.
members := make([]llvm.Type, typ.Results().Len())
for i := 0; i < typ.Results().Len(); i++ {
returnType, err := c.getLLVMType(typ.Results().At(i).Type())
if err != nil {
return llvm.Type{}, err
}
members[i] = returnType
}
returnType = c.ctx.StructType(members, false)
}
// param values
var paramTypes []llvm.Type
if typ.Recv() != nil {
recv, err := c.getLLVMType(typ.Recv().Type())
if err != nil {
return llvm.Type{}, err
}
if recv.StructName() == "runtime._interface" {
recv = c.i8ptrType
}
paramTypes = append(paramTypes, c.expandFormalParamType(recv)...)
}
params := typ.Params()
for i := 0; i < params.Len(); i++ {
subType, err := c.getLLVMType(params.At(i).Type())
if err != nil {
return llvm.Type{}, err
}
paramTypes = append(paramTypes, c.expandFormalParamType(subType)...)
}
var ptr llvm.Type
if c.ir.SignatureNeedsContext(typ) {
// make a closure type (with a function pointer type inside):
// {context, funcptr}
paramTypes = append(paramTypes, c.i8ptrType)
ptr = llvm.PointerType(llvm.FunctionType(returnType, paramTypes, false), 0)
ptr = c.ctx.StructType([]llvm.Type{c.i8ptrType, ptr}, false)
} else {
// make a simple function pointer
ptr = llvm.PointerType(llvm.FunctionType(returnType, paramTypes, false), 0)
}
return ptr, nil
case *types.Slice:
elemType, err := c.getLLVMType(typ.Elem())
if err != nil {
return llvm.Type{}, err
}
members := []llvm.Type{
llvm.PointerType(elemType, 0),
c.lenType, // len
c.lenType, // 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
}
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
}
case llvm.VectorTypeKind:
zero, err := c.getZeroValue(typ.ElementType())
if err != nil {
return llvm.Value{}, err
}
vals := make([]llvm.Value, typ.VectorSize())
for i := range vals {
vals[i] = zero
}
return llvm.ConstVector(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
}
}
// Wrap an interface method function pointer. The wrapper takes in a pointer to
// the underlying value, dereferences it, and calls the real method. This
// wrapper is only needed when the interface value actually doesn't fit in a
// pointer and a pointer to the value must be created.
func (c *Compiler) wrapInterfaceInvoke(f *ir.Function) (llvm.Value, error) {
receiverType, err := c.getLLVMType(f.Params[0].Type())
if err != nil {
return llvm.Value{}, err
}
expandedReceiverType := c.expandFormalParamType(receiverType)
if c.targetData.TypeAllocSize(receiverType) <= c.targetData.TypeAllocSize(c.i8ptrType) && len(expandedReceiverType) == 1 {
// nothing to wrap
return f.LLVMFn, nil
}
// create wrapper function
fnType := f.LLVMFn.Type().ElementType()
paramTypes := append([]llvm.Type{c.i8ptrType}, fnType.ParamTypes()[len(expandedReceiverType):]...)
wrapFnType := llvm.FunctionType(fnType.ReturnType(), paramTypes, false)
wrapper := llvm.AddFunction(c.mod, f.LinkName()+"$invoke", wrapFnType)
wrapper.SetLinkage(llvm.InternalLinkage)
// add debug info
pos := c.ir.Program.Fset.Position(f.Pos())
difunc, err := c.attachDebugInfoRaw(f, wrapper, "$invoke", pos.Filename, pos.Line)
if err != nil {
return llvm.Value{}, err
}
c.builder.SetCurrentDebugLocation(uint(pos.Line), uint(pos.Column), difunc, llvm.Metadata{})
// set up IR builder
block := c.ctx.AddBasicBlock(wrapper, "entry")
c.builder.SetInsertPointAtEnd(block)
var receiverPtr llvm.Value
if c.targetData.TypeAllocSize(receiverType) > c.targetData.TypeAllocSize(c.i8ptrType) {
// The receiver is passed in using a pointer. We have to load it here
// and pass it by value to the real function.
// Load the underlying value.
receiverPtrType := llvm.PointerType(receiverType, 0)
receiverPtr = c.builder.CreateBitCast(wrapper.Param(0), receiverPtrType, "receiver.ptr")
} else if len(expandedReceiverType) != 1 {
// The value is stored in the interface, but it is of type struct which
// is expanded to multiple parameters (e.g. {i8, i8}). So we have to
// receive the struct as parameter, expand it, and pass it on to the
// real function.
// Cast the passed-in i8* to the struct value (using an alloca) and
// extract its values.
alloca := c.builder.CreateAlloca(c.i8ptrType, "receiver.alloca")
c.builder.CreateStore(wrapper.Param(0), alloca)
receiverPtr = c.builder.CreateBitCast(alloca, llvm.PointerType(receiverType, 0), "receiver.ptr")
} else {
panic("unreachable")
}
receiverValue := c.builder.CreateLoad(receiverPtr, "receiver")
params := append(c.expandFormalParam(receiverValue), wrapper.Params()[1:]...)
if fnType.ReturnType().TypeKind() == llvm.VoidTypeKind {
c.builder.CreateCall(f.LLVMFn, params, "")
c.builder.CreateRetVoid()
} else {
ret := c.builder.CreateCall(f.LLVMFn, params, "ret")
c.builder.CreateRet(ret)
}
return wrapper, 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),
blocking: c.ir.IsBlocking(f),
}
var retType llvm.Type
if frame.blocking {
if f.Signature.Results() != nil {
return nil, errors.New("todo: return values in blocking function")
}
retType = c.i8ptrType
} else 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
if frame.blocking {
paramTypes = append(paramTypes, c.i8ptrType) // parent coroutine
}
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...)
}
if c.ir.FunctionNeedsContext(f) {
// This function gets an extra parameter: the context pointer (for
// closures and bound methods). Add it as an extra paramter here.
paramTypes = append(paramTypes, c.i8ptrType)
}
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)
}
if c.Debug && f.Synthetic == "package initializer" {
difunc, err := c.attachDebugInfoRaw(f, f.LLVMFn, "", "", 0)
if err != nil {
return nil, err
}
frame.difunc = difunc
} else if c.Debug && f.Syntax() != nil && len(f.Blocks) != 0 {
// Create debug info file if needed.
difunc, err := c.attachDebugInfo(f)
if err != nil {
return nil, err
}
frame.difunc = difunc
}
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
}
// Create a new global hashmap bucket, for map initialization.
func (c *Compiler) initMapNewBucket(prefix string, mapType *types.Map) (llvm.Value, uint64, uint64, error) {
llvmKeyType, err := c.getLLVMType(mapType.Key().Underlying())
if err != nil {
return llvm.Value{}, 0, 0, err
}
llvmValueType, err := c.getLLVMType(mapType.Elem().Underlying())
if err != nil {
return llvm.Value{}, 0, 0, err
}
keySize := c.targetData.TypeAllocSize(llvmKeyType)
valueSize := c.targetData.TypeAllocSize(llvmValueType)
bucketType := c.ctx.StructType([]llvm.Type{
llvm.ArrayType(c.ctx.Int8Type(), 8), // tophash
c.i8ptrType, // next bucket
llvm.ArrayType(llvmKeyType, 8), // key type
llvm.ArrayType(llvmValueType, 8), // value type
}, false)
bucketValue, err := c.getZeroValue(bucketType)
if err != nil {
return llvm.Value{}, 0, 0, err
}
bucket := llvm.AddGlobal(c.mod, bucketType, prefix+"$hashmap$bucket")
bucket.SetInitializer(bucketValue)
bucket.SetLinkage(llvm.InternalLinkage)
return bucket, keySize, valueSize, nil
}
func (c *Compiler) parseGlobalInitializer(g *ir.Global) error {
if g.IsExtern() {
return nil
}
llvmValue, err := c.getInterpretedValue(g.LinkName(), g.Initializer())
if err != nil {
return err
}
g.LLVMGlobal.SetInitializer(llvmValue)
return nil
}
// Turn a computed Value type (ConstValue, ArrayValue, etc.) into a LLVM value.
// This is used to set the initializer of globals after they have been
// calculated by the package initializer interpreter.
func (c *Compiler) getInterpretedValue(prefix string, value ir.Value) (llvm.Value, error) {
switch value := value.(type) {
case *ir.ArrayValue:
vals := make([]llvm.Value, len(value.Elems))
for i, elem := range value.Elems {
val, err := c.getInterpretedValue(prefix+"$arrayval", elem)
if err != nil {
return llvm.Value{}, err
}
vals[i] = val
}
subTyp, err := c.getLLVMType(value.ElemType)
if err != nil {
return llvm.Value{}, err
}
return llvm.ConstArray(subTyp, vals), nil
case *ir.ConstValue:
return c.parseConst(prefix, value.Expr)
case *ir.FunctionValue:
if value.Elem == nil {
llvmType, err := c.getLLVMType(value.Type)
if err != nil {
return llvm.Value{}, err
}
return c.getZeroValue(llvmType)
}
fn := c.ir.GetFunction(value.Elem)
ptr := fn.LLVMFn
if c.ir.SignatureNeedsContext(fn.Signature) {
// Create closure value: {context, function pointer}
ptr = c.ctx.ConstStruct([]llvm.Value{llvm.ConstPointerNull(c.i8ptrType), ptr}, false)
}
return ptr, nil
case *ir.GlobalValue:
zero := llvm.ConstInt(c.ctx.Int32Type(), 0, false)
ptr := llvm.ConstInBoundsGEP(value.Global.LLVMGlobal, []llvm.Value{zero})
return ptr, nil
case *ir.InterfaceValue:
underlying := llvm.ConstPointerNull(c.i8ptrType) // could be any 0 value
if value.Elem != nil {
elem, err := c.getInterpretedValue(prefix, value.Elem)
if err != nil {
return llvm.Value{}, err
}
underlying = elem
}
return c.parseMakeInterface(underlying, value.Type, prefix)
case *ir.MapValue:
// Create initial bucket.
firstBucketGlobal, keySize, valueSize, err := c.initMapNewBucket(prefix, value.Type)
if err != nil {
return llvm.Value{}, err
}
// Insert each key/value pair in the hashmap.
bucketGlobal := firstBucketGlobal
for i, key := range value.Keys {
llvmKey, err := c.getInterpretedValue(prefix, key)
if err != nil {
return llvm.Value{}, nil
}
llvmValue, err := c.getInterpretedValue(prefix, value.Values[i])
if err != nil {
return llvm.Value{}, nil
}
constVal := key.(*ir.ConstValue).Expr
var keyBuf []byte
switch constVal.Type().Underlying().(*types.Basic).Kind() {
case types.String, types.UntypedString:
keyBuf = []byte(constant.StringVal(constVal.Value))
case types.Int:
keyBuf = make([]byte, c.targetData.TypeAllocSize(c.intType))
n, _ := constant.Uint64Val(constVal.Value)
for i := range keyBuf {
keyBuf[i] = byte(n)
n >>= 8
}
default:
return llvm.Value{}, errors.New("todo: init: map key not implemented: " + constVal.Type().Underlying().String())
}
hash := hashmapHash(keyBuf)
if i%8 == 0 && i != 0 {
// Bucket is full, create a new one.
newBucketGlobal, _, _, err := c.initMapNewBucket(prefix, value.Type)
if err != nil {
return llvm.Value{}, err
}
zero := llvm.ConstInt(c.ctx.Int32Type(), 0, false)
newBucketPtr := llvm.ConstInBoundsGEP(newBucketGlobal, []llvm.Value{zero})
newBucketPtrCast := llvm.ConstBitCast(newBucketPtr, c.i8ptrType)
// insert pointer into old bucket
bucket := bucketGlobal.Initializer()
bucket = llvm.ConstInsertValue(bucket, newBucketPtrCast, []uint32{1})
bucketGlobal.SetInitializer(bucket)
// switch to next bucket
bucketGlobal = newBucketGlobal
}
tophashValue := llvm.ConstInt(c.ctx.Int8Type(), uint64(hashmapTopHash(hash)), false)
bucket := bucketGlobal.Initializer()
bucket = llvm.ConstInsertValue(bucket, tophashValue, []uint32{0, uint32(i % 8)})
bucket = llvm.ConstInsertValue(bucket, llvmKey, []uint32{2, uint32(i % 8)})
bucket = llvm.ConstInsertValue(bucket, llvmValue, []uint32{3, uint32(i % 8)})
bucketGlobal.SetInitializer(bucket)
}
// Create the hashmap itself.
zero := llvm.ConstInt(c.ctx.Int32Type(), 0, false)
bucketPtr := llvm.ConstInBoundsGEP(firstBucketGlobal, []llvm.Value{zero})
hashmapType := c.mod.GetTypeByName("runtime.hashmap")
hashmap := llvm.ConstNamedStruct(hashmapType, []llvm.Value{
llvm.ConstPointerNull(llvm.PointerType(hashmapType, 0)), // next
llvm.ConstBitCast(bucketPtr, c.i8ptrType), // buckets
llvm.ConstInt(c.lenType, uint64(len(value.Keys)), false), // count
llvm.ConstInt(c.ctx.Int8Type(), keySize, false), // keySize
llvm.ConstInt(c.ctx.Int8Type(), valueSize, false), // valueSize
llvm.ConstInt(c.ctx.Int8Type(), 0, false), // bucketBits
})
// Create a pointer to this hashmap.
hashmapPtr := llvm.AddGlobal(c.mod, hashmap.Type(), prefix+"$hashmap")
hashmapPtr.SetInitializer(hashmap)
hashmapPtr.SetLinkage(llvm.InternalLinkage)
return llvm.ConstInBoundsGEP(hashmapPtr, []llvm.Value{zero}), nil
case *ir.PointerBitCastValue:
elem, err := c.getInterpretedValue(prefix, value.Elem)
if err != nil {
return llvm.Value{}, err
}
llvmType, err := c.getLLVMType(value.Type)
if err != nil {
return llvm.Value{}, err
}
return llvm.ConstBitCast(elem, llvmType), nil
case *ir.PointerToUintptrValue:
elem, err := c.getInterpretedValue(prefix, value.Elem)
if err != nil {
return llvm.Value{}, err
}
return llvm.ConstPtrToInt(elem, c.uintptrType), nil
case *ir.PointerValue:
if value.Elem == nil {
typ, err := c.getLLVMType(value.Type)
if err != nil {
return llvm.Value{}, err
}
return llvm.ConstPointerNull(typ), nil
}
elem, err := c.getInterpretedValue(prefix, *value.Elem)
if err != nil {
return llvm.Value{}, err
}
obj := llvm.AddGlobal(c.mod, elem.Type(), prefix+"$ptrvalue")
obj.SetInitializer(elem)
obj.SetLinkage(llvm.InternalLinkage)
elem = obj
zero := llvm.ConstInt(c.ctx.Int32Type(), 0, false)
ptr := llvm.ConstInBoundsGEP(elem, []llvm.Value{zero})
return ptr, nil
case *ir.SliceValue:
var globalPtr llvm.Value
var arrayLength uint64
if value.Array == nil {
arrayType, err := c.getLLVMType(value.Type.Elem())
if err != nil {
return llvm.Value{}, err
}
globalPtr = llvm.ConstPointerNull(llvm.PointerType(arrayType, 0))
} else {
// make array
array, err := c.getInterpretedValue(prefix, value.Array)
if err != nil {
return llvm.Value{}, err
}
// make global from array
global := llvm.AddGlobal(c.mod, array.Type(), prefix+"$array")
global.SetInitializer(array)
global.SetLinkage(llvm.InternalLinkage)
// get pointer to global
zero := llvm.ConstInt(c.ctx.Int32Type(), 0, false)
globalPtr = c.builder.CreateInBoundsGEP(global, []llvm.Value{zero, zero}, "")
arrayLength = uint64(len(value.Array.Elems))
}
// make slice
sliceTyp, err := c.getLLVMType(value.Type)
if err != nil {
return llvm.Value{}, err
}
llvmLen := llvm.ConstInt(c.lenType, arrayLength, false)
slice := llvm.ConstNamedStruct(sliceTyp, []llvm.Value{
globalPtr, // ptr
llvmLen, // len
llvmLen, // cap
})
return slice, nil
case *ir.StructValue:
fields := make([]llvm.Value, len(value.Fields))
for i, elem := range value.Fields {
field, err := c.getInterpretedValue(prefix, elem)
if err != nil {
return llvm.Value{}, err
}
fields[i] = field
}
switch value.Type.(type) {
case *types.Named:
llvmType, err := c.getLLVMType(value.Type)
if err != nil {
return llvm.Value{}, err
}
return llvm.ConstNamedStruct(llvmType, fields), nil
case *types.Struct:
return c.ctx.ConstStruct(fields, false), nil
default:
return llvm.Value{}, errors.New("init: unknown struct type: " + value.Type.String())
}
case *ir.ZeroBasicValue:
llvmType, err := c.getLLVMType(value.Type)
if err != nil {
return llvm.Value{}, err
}
return c.getZeroValue(llvmType)
default:
return llvm.Value{}, errors.New("init: unknown initializer type: " + fmt.Sprintf("%#v", value))
}
}
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)
}
if frame.fn.IsInterrupt() && strings.HasPrefix(c.Triple, "avr") {
frame.fn.LLVMFn.SetFunctionCallConv(85) // CallingConv::AVR_SIGNAL
}
if c.Debug {
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
}
if frame.blocking {
frame.cleanupBlock = c.ctx.AddBasicBlock(frame.fn.LLVMFn, "task.cleanup")
frame.suspendBlock = c.ctx.AddBasicBlock(frame.fn.LLVMFn, "task.suspend")
}
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).
if len(frame.fn.FreeVars) != 0 {
if !c.ir.FunctionNeedsContext(frame.fn) {
panic("free variables on function without context")
}
context := frame.fn.LLVMFn.LastParam()
context.SetName("context")
// 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), "")
contextRawValue := c.builder.CreateBitCast(context, llvm.PointerType(c.i8ptrType, 0), "")
c.builder.CreateStore(contextRawValue, contextRawAlloc)
contextAlloc = c.builder.CreateBitCast(contextRawAlloc, llvm.PointerType(contextType, 0), "")
} 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), "")
}
// 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 {
// Create defer list pointer.
deferType := llvm.PointerType(c.mod.GetTypeByName("runtime._defer"), 0)
frame.deferPtr = c.builder.CreateAlloca(deferType, "deferPtr")
c.builder.CreateStore(llvm.ConstPointerNull(deferType), frame.deferPtr)
}
if frame.blocking {
// Coroutine initialization.
taskState := c.builder.CreateAlloca(c.mod.GetTypeByName("runtime.taskState"), "task.state")
stateI8 := c.builder.CreateBitCast(taskState, c.i8ptrType, "task.state.i8")
id := c.builder.CreateCall(c.coroIdFunc, []llvm.Value{
llvm.ConstInt(c.ctx.Int32Type(), 0, false),
stateI8,
llvm.ConstNull(c.i8ptrType),
llvm.ConstNull(c.i8ptrType),
}, "task.token")
size := c.builder.CreateCall(c.coroSizeFunc, nil, "task.size")
if c.targetData.TypeAllocSize(size.Type()) > c.targetData.TypeAllocSize(c.uintptrType) {
size = c.builder.CreateTrunc(size, c.uintptrType, "task.size.uintptr")
} else if c.targetData.TypeAllocSize(size.Type()) < c.targetData.TypeAllocSize(c.uintptrType) {
size = c.builder.CreateZExt(size, c.uintptrType, "task.size.uintptr")
}
data := c.createRuntimeCall("alloc", []llvm.Value{size}, "task.data")
frame.taskHandle = c.builder.CreateCall(c.coroBeginFunc, []llvm.Value{id, data}, "task.handle")
// Coroutine cleanup. Free resources associated with this coroutine.
c.builder.SetInsertPointAtEnd(frame.cleanupBlock)
mem := c.builder.CreateCall(c.coroFreeFunc, []llvm.Value{id, frame.taskHandle}, "task.data.free")
c.createRuntimeCall("free", []llvm.Value{mem}, "")
// re-insert parent coroutine
c.createRuntimeCall("yieldToScheduler", []llvm.Value{frame.fn.LLVMFn.FirstParam()}, "")
c.builder.CreateBr(frame.suspendBlock)
// Coroutine suspend. A call to llvm.coro.suspend() will branch here.
c.builder.SetInsertPointAtEnd(frame.suspendBlock)
c.builder.CreateCall(c.coroEndFunc, []llvm.Value{frame.taskHandle, llvm.ConstInt(c.ctx.Int1Type(), 0, false)}, "unused")
c.builder.CreateRet(frame.taskHandle)
}
// 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)
if err == ir.ErrCGoWrapper {
// Ignore CGo global variables which we don't use.
return nil
}
frame.locals[instr] = value
return err
case *ssa.DebugRef:
return nil // ignore
case *ssa.Defer:
// The pointer to the previous defer struct, which we will replace to
// make a linked list.
next := c.builder.CreateLoad(frame.deferPtr, "defer.next")
deferFuncType := llvm.FunctionType(c.ctx.VoidType(), []llvm.Type{next.Type()}, false)
var values []llvm.Value
var valueTypes []llvm.Type
if callee, ok := instr.Call.Value.(*ssa.Function); ok && !instr.Call.IsInvoke() {
// Regular function call.
fn := c.ir.GetFunction(callee)
// Try to find the wrapper $defer function.
deferName := fn.LinkName() + "$defer"
callback := c.mod.NamedFunction(deferName)
if callback.IsNil() {
// Not found, have to add it.
callback = llvm.AddFunction(c.mod, deferName, deferFuncType)
c.deferFuncs = append(c.deferFuncs, fn)
}
// Collect all values to be put in the struct (starting with
// runtime._defer fields).
values = []llvm.Value{callback, next}
valueTypes = []llvm.Type{callback.Type(), next.Type()}
for _, param := range instr.Call.Args {
llvmParam, err := c.parseExpr(frame, param)
if err != nil {
return err
}
values = append(values, llvmParam)
valueTypes = append(valueTypes, llvmParam.Type())
}
} else if makeClosure, ok := instr.Call.Value.(*ssa.MakeClosure); ok {
// Immediately applied function literal with free variables.
closure, err := c.parseExpr(frame, instr.Call.Value)
if err != nil {
return err
}
// Hopefully, LLVM will merge equivalent functions.
deferName := frame.fn.LinkName() + "$fpdefer"
callback := llvm.AddFunction(c.mod, deferName, deferFuncType)
// Collect all values to be put in the struct (starting with
// runtime._defer fields, followed by the closure).
values = []llvm.Value{callback, next, closure}
valueTypes = []llvm.Type{callback.Type(), next.Type(), closure.Type()}
for _, param := range instr.Call.Args {
llvmParam, err := c.parseExpr(frame, param)
if err != nil {
return err
}
values = append(values, llvmParam)
valueTypes = append(valueTypes, llvmParam.Type())
}
thunk := ContextDeferFunction{
callback,
valueTypes,
makeClosure.Fn.(*ssa.Function).Signature,
}
c.ctxDeferFuncs = append(c.ctxDeferFuncs, thunk)
} else {
return errors.New("todo: defer on uncommon function call type")
}
// Make a struct out of the collected values to put in the defer frame.
deferFrameType := c.ctx.StructType(valueTypes, false)
deferFrame, err := c.getZeroValue(deferFrameType)
if err != nil {
return err
}
for i, value := range values {
deferFrame = c.builder.CreateInsertValue(deferFrame, value, i, "")
}
// Put this struct in an alloca.
alloca := c.builder.CreateAlloca(deferFrameType, "defer.alloca")
c.builder.CreateStore(deferFrame, alloca)
// Push it on top of the linked list by replacing deferPtr.
allocaCast := c.builder.CreateBitCast(alloca, next.Type(), "defer.alloca.cast")
c.builder.CreateStore(allocaCast, frame.deferPtr)
return nil
case *ssa.Go:
if instr.Common().Method != nil {
return errors.New("todo: go on method receiver")
}
// Execute non-blocking calls (including builtins) directly.
// parentHandle param is ignored.
if !c.ir.IsBlocking(c.ir.GetFunction(instr.Common().Value.(*ssa.Function))) {
_, err := c.parseCall(frame, instr.Common(), llvm.Value{})
return err // probably nil
}
// Start this goroutine.
// parentHandle is nil, as the goroutine has no parent frame (it's a new
// stack).
handle, err := c.parseCall(frame, instr.Common(), llvm.Value{})
if err != nil {
return err
}
c.createRuntimeCall("yieldToScheduler", []llvm.Value{handle}, "")
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)
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 frame.blocking {
if len(instr.Results) != 0 {
return errors.New("todo: return values from blocking function")
}
// Final suspend.
continuePoint := c.builder.CreateCall(c.coroSuspendFunc, []llvm.Value{
llvm.ConstNull(c.ctx.TokenType()),
llvm.ConstInt(c.ctx.Int1Type(), 1, false), // final=true
}, "")
sw := c.builder.CreateSwitch(continuePoint, frame.suspendBlock, 2)
sw.AddCase(llvm.ConstInt(c.ctx.Int8Type(), 1, false), frame.cleanupBlock)
return nil
} else {
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:
deferData := c.builder.CreateLoad(frame.deferPtr, "")
c.createRuntimeCall("rundefers", []llvm.Value{deferData}, "")
return nil
case *ssa.Store:
llvmAddr, err := c.parseExpr(frame, instr.Addr)
if err == ir.ErrCGoWrapper {
// Ignore CGo global variables which we don't use.
return nil
}
if err != nil {
return err
}
llvmVal, err := c.parseExpr(frame, instr.Val)
if err != nil {
return err
}
store := c.builder.CreateStore(llvmVal, llvmAddr)
valType := instr.Addr.Type().(*types.Pointer).Elem()
if c.ir.IsVolatile(valType) {
// Volatile store, for memory-mapped registers.
store.SetVolatile(true)
}
return nil
default:
return errors.New("unknown instruction: " + instr.String())
}
}
func (c *Compiler) parseBuiltin(frame *Frame, args []ssa.Value, callName string) (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
}
switch args[0].Type().(type) {
case *types.Slice:
return c.builder.CreateExtractValue(value, 2, "cap"), nil
default:
return llvm.Value{}, errors.New("todo: cap: unknown type")
}
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(llvm.VectorType(c.ctx.FloatType(), 2))
case types.Float64:
cplx = llvm.Undef(llvm.VectorType(c.ctx.DoubleType(), 2))
default:
return llvm.Value{}, errors.New("unsupported type in complex builtin: " + t.String())
}
cplx = c.builder.CreateInsertElement(cplx, r, llvm.ConstInt(c.ctx.Int8Type(), 0, false), "")
cplx = c.builder.CreateInsertElement(cplx, i, llvm.ConstInt(c.ctx.Int8Type(), 1, false), "")
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)
case "imag":
cplx, err := c.parseExpr(frame, args[0])
if err != nil {
return llvm.Value{}, err
}
index := llvm.ConstInt(c.ctx.Int32Type(), 1, false)
return c.builder.CreateExtractElement(cplx, index, "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.Map:
indices := []llvm.Value{
llvm.ConstInt(c.ctx.Int32Type(), 0, false),
llvm.ConstInt(c.ctx.Int32Type(), 2, false), // hashmap.count
}
ptr := c.builder.CreateGEP(value, indices, "lenptr")
llvmLen = c.builder.CreateLoad(ptr, "len")
default:
return llvm.Value{}, errors.New("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{}, errors.New("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{}, errors.New("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
}
index := llvm.ConstInt(c.ctx.Int32Type(), 0, false)
return c.builder.CreateExtractElement(cplx, index, "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{}, errors.New("todo: builtin: " + callName)
}
}
func (c *Compiler) parseFunctionCall(frame *Frame, args []ssa.Value, llvmFn, context llvm.Value, blocking bool, parentHandle llvm.Value) (llvm.Value, error) {
var params []llvm.Value
if blocking {
if parentHandle.IsNil() {
// Started from 'go' statement.
params = append(params, llvm.ConstNull(c.i8ptrType))
} else {
// Blocking function calls another blocking function.
params = append(params, parentHandle)
}
}
for _, param := range args {
val, err := c.parseExpr(frame, param)
if err != nil {
return llvm.Value{}, err
}
params = append(params, val)
}
if !context.IsNil() {
// This function takes a context parameter.
// Add it to the end of the parameter list.
params = append(params, context)
}
if frame.blocking && llvmFn.Name() == "time.Sleep" {
// Set task state to TASK_STATE_SLEEP and set the duration.
c.createRuntimeCall("sleepTask", []llvm.Value{frame.taskHandle, params[0]}, "")
// Yield to scheduler.
continuePoint := c.builder.CreateCall(c.coroSuspendFunc, []llvm.Value{
llvm.ConstNull(c.ctx.TokenType()),
llvm.ConstInt(c.ctx.Int1Type(), 0, false),
}, "")
wakeup := c.ctx.InsertBasicBlock(llvm.NextBasicBlock(c.builder.GetInsertBlock()), "task.wakeup")
sw := c.builder.CreateSwitch(continuePoint, frame.suspendBlock, 2)
sw.AddCase(llvm.ConstInt(c.ctx.Int8Type(), 0, false), wakeup)
sw.AddCase(llvm.ConstInt(c.ctx.Int8Type(), 1, false), frame.cleanupBlock)
c.builder.SetInsertPointAtEnd(wakeup)
return llvm.Value{}, nil
}
result := c.createCall(llvmFn, params, "")
if blocking && !parentHandle.IsNil() {
// Calling a blocking function as a regular function call.
// This is done by passing the current coroutine as a parameter to the
// new coroutine and dropping the current coroutine from the scheduler
// (with the TASK_STATE_CALL state). When the subroutine is finished, it
// will reactivate the parent (this frame) in it's destroy function.
c.createRuntimeCall("yieldToScheduler", []llvm.Value{result}, "")
// Set task state to TASK_STATE_CALL.
c.createRuntimeCall("waitForAsyncCall", []llvm.Value{frame.taskHandle}, "")
// Yield to the scheduler.
continuePoint := c.builder.CreateCall(c.coroSuspendFunc, []llvm.Value{
llvm.ConstNull(c.ctx.TokenType()),
llvm.ConstInt(c.ctx.Int1Type(), 0, false),
}, "")
resume := c.ctx.InsertBasicBlock(llvm.NextBasicBlock(c.builder.GetInsertBlock()), "task.callComplete")
sw := c.builder.CreateSwitch(continuePoint, frame.suspendBlock, 2)
sw.AddCase(llvm.ConstInt(c.ctx.Int8Type(), 0, false), resume)
sw.AddCase(llvm.ConstInt(c.ctx.Int8Type(), 1, false), frame.cleanupBlock)
c.builder.SetInsertPointAtEnd(resume)
}
return result, nil
}
func (c *Compiler) parseCall(frame *Frame, instr *ssa.CallCommon, parentHandle llvm.Value) (llvm.Value, error) {
if instr.IsInvoke() {
// Call an interface method with dynamic dispatch.
itf, err := c.parseExpr(frame, instr.Value) // interface
if err != nil {
return llvm.Value{}, err
}
llvmFnType, err := c.getLLVMType(instr.Method.Type())
if err != nil {
return llvm.Value{}, err
}
if c.ir.SignatureNeedsContext(instr.Method.Type().(*types.Signature)) {
// This is somewhat of a hack.
// getLLVMType() has created a closure type for us, but we don't
// actually want a closure type as an interface call can never be a
// closure call. So extract the function pointer type from the
// closure.
// This happens because somewhere the same function signature is
// used in a closure or bound method.
llvmFnType = llvmFnType.Subtypes()[1]
}
values := []llvm.Value{
itf,
llvm.ConstInt(c.ctx.Int16Type(), uint64(c.ir.MethodNum(instr.Method)), false),
}
fn := c.createRuntimeCall("interfaceMethod", values, "invoke.func")
fnCast := c.builder.CreateBitCast(fn, llvmFnType, "invoke.func.cast")
receiverValue := c.builder.CreateExtractValue(itf, 1, "invoke.func.receiver")
args := []llvm.Value{receiverValue}
for _, arg := range instr.Args {
val, err := c.parseExpr(frame, arg)
if err != nil {
return llvm.Value{}, err
}
args = append(args, val)
}
if c.ir.SignatureNeedsContext(instr.Method.Type().(*types.Signature)) {
// This function takes an extra context parameter. An interface call
// cannot also be a closure but we have to supply the nil pointer
// anyway.
args = append(args, llvm.ConstPointerNull(c.i8ptrType))
}
// TODO: blocking methods (needs analysis)
return c.createCall(fnCast, args, ""), nil
}
// Try to call the function directly for trivially static calls.
if fn := instr.StaticCallee(); fn != nil {
if fn.RelString(nil) == "device/arm.Asm" || fn.RelString(nil) == "device/avr.Asm" {
// Magic function: insert inline assembly instead of calling it.
fnType := llvm.FunctionType(c.ctx.VoidType(), []llvm.Type{}, false)
asm := constant.StringVal(instr.Args[0].(*ssa.Const).Value)
target := llvm.InlineAsm(fnType, asm, "", true, false, 0)
return c.builder.CreateCall(target, nil, ""), nil
}
if fn.RelString(nil) == "device/arm.AsmFull" || fn.RelString(nil) == "device/avr.AsmFull" {
asmString := constant.StringVal(instr.Args[0].(*ssa.Const).Value)
registers := map[string]llvm.Value{}
registerMap := instr.Args[1].(*ssa.MakeMap)
for _, r := range *registerMap.Referrers() {
switch r := r.(type) {
case *ssa.DebugRef:
// ignore
case *ssa.MapUpdate:
if r.Block() != registerMap.Block() {
return llvm.Value{}, errors.New("register value map must be created in the same basic block")
}
key := constant.StringVal(r.Key.(*ssa.Const).Value)
//println("value:", r.Value.(*ssa.MakeInterface).X.String())
value, err := c.parseExpr(frame, r.Value.(*ssa.MakeInterface).X)
if err != nil {
return llvm.Value{}, err
}
registers[key] = value
case *ssa.Call:
if r.Common() == instr {
break
}
default:
return llvm.Value{}, errors.New("don't know how to handle argument to inline assembly: " + r.String())
}
}
// TODO: handle dollar signs in asm string
registerNumbers := map[string]int{}
var err error
argTypes := []llvm.Type{}
args := []llvm.Value{}
constraints := []string{}
asmString = regexp.MustCompile("\\{[a-zA-Z]+\\}").ReplaceAllStringFunc(asmString, func(s string) string {
// TODO: skip strings like {r4} etc. that look like ARM push/pop
// instructions.
name := s[1 : len(s)-1]
if _, ok := registers[name]; !ok {
if err == nil {
err = errors.New("unknown register name: " + name)
}
return s
}
if _, ok := registerNumbers[name]; !ok {
registerNumbers[name] = len(registerNumbers)
argTypes = append(argTypes, registers[name].Type())
args = append(args, registers[name])
switch registers[name].Type().TypeKind() {
case llvm.IntegerTypeKind:
constraints = append(constraints, "r")
case llvm.PointerTypeKind:
constraints = append(constraints, "*m")
default:
err = errors.New("unknown type in inline assembly for value: " + name)
return s
}
}
return fmt.Sprintf("${%v}", registerNumbers[name])
})
if err != nil {
return llvm.Value{}, err
}
fnType := llvm.FunctionType(c.ctx.VoidType(), argTypes, false)
target := llvm.InlineAsm(fnType, asmString, strings.Join(constraints, ","), true, false, 0)
return c.builder.CreateCall(target, args, ""), nil
}
targetFunc := c.ir.GetFunction(fn)
if targetFunc.LLVMFn.IsNil() {
return llvm.Value{}, errors.New("undefined function: " + targetFunc.LinkName())
}
var context llvm.Value
if c.ir.FunctionNeedsContext(targetFunc) {
// This function call is to a (potential) closure, not a regular
// function. See whether it is a closure and if so, call it as such.
// Else, supply a dummy nil pointer as the last parameter.
var err error
if mkClosure, ok := instr.Value.(*ssa.MakeClosure); ok {
// closure is {context, function pointer}
closure, err := c.parseExpr(frame, mkClosure)
if err != nil {
return llvm.Value{}, err
}
context = c.builder.CreateExtractValue(closure, 0, "")
} else {
context, err = c.getZeroValue(c.i8ptrType)
if err != nil {
return llvm.Value{}, err
}
}
}
return c.parseFunctionCall(frame, instr.Args, targetFunc.LLVMFn, context, c.ir.IsBlocking(targetFunc), parentHandle)
}
// Builtin or function pointer.
switch call := instr.Value.(type) {
case *ssa.Builtin:
return c.parseBuiltin(frame, instr.Args, call.Name())
default: // function pointer
value, err := c.parseExpr(frame, instr.Value)
if err != nil {
return llvm.Value{}, err
}
// TODO: blocking function pointers (needs analysis)
var context llvm.Value
if c.ir.SignatureNeedsContext(instr.Signature()) {
// 'value' is a closure, not a raw function pointer.
// Extract the function pointer and the context pointer.
// closure: {context, function pointer}
context = c.builder.CreateExtractValue(value, 0, "")
value = c.builder.CreateExtractValue(value, 1, "")
}
return c.parseFunctionCall(frame, instr.Args, value, context, false, parentHandle)
}
}
func (c *Compiler) emitBoundsCheck(frame *Frame, arrayLen, index llvm.Value, indexType types.Type) {
if frame.fn.IsNoBounds() {
// The //go:nobounds pragma was added to the function to avoid bounds
// checking.
return
}
// Sometimes, the index can be e.g. an uint8 or int8, and we have to
// correctly extend that type.
if index.Type().IntTypeWidth() < arrayLen.Type().IntTypeWidth() {
if indexType.(*types.Basic).Info()&types.IsUnsigned == 0 {
index = c.builder.CreateZExt(index, arrayLen.Type(), "")
} else {
index = c.builder.CreateSExt(index, arrayLen.Type(), "")
}
}
// Optimize away trivial cases.
// LLVM would do this anyway with interprocedural optimizations, but it
// helps to see cases where bounds check elimination would really help.
if index.IsConstant() && arrayLen.IsConstant() && !arrayLen.IsUndef() {
index := index.SExtValue()
arrayLen := arrayLen.SExtValue()
if index >= 0 && index < arrayLen {
return
}
}
if index.Type().IntTypeWidth() > c.intType.IntTypeWidth() {
// Index is too big for the regular bounds check. Use the one for int64.
c.createRuntimeCall("lookupBoundsCheckLong", []llvm.Value{arrayLen, index}, "")
} else {
c.createRuntimeCall("lookupBoundsCheck", []llvm.Value{arrayLen, index}, "")
}
}
func (c *Compiler) emitSliceBoundsCheck(frame *Frame, length, low, high llvm.Value) {
if frame.fn.IsNoBounds() {
// The //go:nobounds pragma was added to the function to avoid bounds
// checking.
return
}
if low.Type().IntTypeWidth() > 32 || high.Type().IntTypeWidth() > 32 {
if low.Type().IntTypeWidth() < 64 {
low = c.builder.CreateSExt(low, c.ctx.Int64Type(), "")
}
if high.Type().IntTypeWidth() < 64 {
high = c.builder.CreateSExt(high, c.ctx.Int64Type(), "")
}
c.createRuntimeCall("sliceBoundsCheckLong", []llvm.Value{length, low, high}, "")
} else {
c.createRuntimeCall("sliceBoundsCheck", []llvm.Value{length, low, high}, "")
}
}
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{}, errors.New("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 {
// TODO: escape analysis
size := llvm.ConstInt(c.uintptrType, c.targetData.TypeAllocSize(typ), false)
buf = c.createRuntimeCall("alloc", []llvm.Value{size}, expr.Comment)
buf = c.builder.CreateBitCast(buf, llvm.PointerType(typ, 0), "")
} else {
buf = c.builder.CreateAlloca(typ, expr.Comment)
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().Underlying(), x, y)
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(), frame.taskHandle)
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:
x, err := c.parseExpr(frame, expr.X)
if err != nil {
return llvm.Value{}, err
}
// The only case when we need to bitcast is when casting between named
// struct types, as those are actually different in LLVM. Let's just
// bitcast all struct types for ease of use.
if _, ok := expr.Type().Underlying().(*types.Struct); ok {
llvmType, err := c.getLLVMType(expr.X.Type())
if err != nil {
return llvm.Value{}, err
}
return c.builder.CreateBitCast(x, llvmType, "changetype"), nil
}
return x, nil
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)
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
}
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
}
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)
ptr := fn.LLVMFn
if c.ir.FunctionNeedsContext(fn) {
// Create closure for function pointer.
// Closure is: {context, function pointer}
ptr = c.ctx.ConstStruct([]llvm.Value{
llvm.ConstPointerNull(c.i8ptrType),
ptr,
}, false)
}
return ptr, nil
case *ssa.Global:
if strings.HasPrefix(expr.Name(), "__cgofn__cgo_") || strings.HasPrefix(expr.Name(), "_cgo_") {
// Ignore CGo global variables which we don't use.
return llvm.Value{}, ir.ErrCGoWrapper
}
value := c.ir.GetGlobal(expr).LLVMGlobal
if value.IsNil() {
return llvm.Value{}, errors.New("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.lenType, uint64(arrayLen), false)
c.emitBoundsCheck(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(), "")
c.builder.CreateStore(array, alloca)
zero := llvm.ConstInt(c.ctx.Int32Type(), 0, false)
ptr := c.builder.CreateGEP(alloca, []llvm.Value{zero, index}, "")
return c.builder.CreateLoad(ptr, ""), 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().(*types.Pointer).Elem().Underlying()
switch typ := typ.(type) {
case *types.Array:
bufptr = val
buflen = llvm.ConstInt(c.lenType, uint64(typ.Len()), false)
default:
return llvm.Value{}, errors.New("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{}, errors.New("todo: indexaddr: " + ptrTyp.String())
}
// Bounds check.
// LLVM optimizes this away in most cases.
c.emitBoundsCheck(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.
// LLVM optimizes this away in most cases.
length, err := c.parseBuiltin(frame, []ssa.Value{expr.X}, "len")
if err != nil {
return llvm.Value{}, err // shouldn't happen
}
c.emitBoundsCheck(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)
default:
panic("unknown lookup type: " + expr.String())
}
case *ssa.MakeClosure:
// A closure returns a function pointer with context:
// {context, fp}
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(), "")
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)
// Bounds checking.
if !frame.fn.IsNoBounds() {
c.createRuntimeCall("sliceBoundsCheckMake", []llvm.Value{sliceLen, sliceCap}, "")
}
// Allocate the backing array.
// TODO: escape analysis
elemSizeValue := llvm.ConstInt(c.uintptrType, elemSize, false)
sliceCapCast, err := c.parseConvert(expr.Cap.Type(), types.Typ[types.Uintptr], sliceCap)
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")
if c.targetData.TypeAllocSize(sliceLen.Type()) > c.targetData.TypeAllocSize(c.lenType) {
sliceLen = c.builder.CreateTrunc(sliceLen, c.lenType, "")
sliceCap = c.builder.CreateTrunc(sliceCap, c.lenType, "")
}
// Create the slice.
slice := c.ctx.ConstStruct([]llvm.Value{
llvm.Undef(slicePtr.Type()),
llvm.Undef(c.lenType),
llvm.Undef(c.lenType),
}, 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().(*types.Map).Key())
if err != nil {
return llvm.Value{}, err
}
llvmValueType, err := c.getLLVMType(rangeVal.Type().(*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.Slice:
if expr.Max != nil {
return llvm.Value{}, errors.New("todo: full slice expressions (with max): " + expr.Type().String())
}
value, err := c.parseExpr(frame, expr.X)
if err != nil {
return llvm.Value{}, err
}
var low, high llvm.Value
if expr.Low == nil {
low = llvm.ConstInt(c.intType, 0, false)
} else {
low, err = c.parseExpr(frame, expr.Low)
if err != nil {
return llvm.Value{}, nil
}
}
if expr.High != nil {
high, err = c.parseExpr(frame, expr.High)
if err != nil {
return llvm.Value{}, nil
}
}
switch typ := expr.X.Type().Underlying().(type) {
case *types.Pointer: // pointer to array
// slice an array
length := typ.Elem().(*types.Array).Len()
llvmLen := llvm.ConstInt(c.lenType, uint64(length), false)
llvmLenInt := llvm.ConstInt(c.intType, uint64(length), false)
if high.IsNil() {
high = llvmLenInt
}
indices := []llvm.Value{
llvm.ConstInt(c.ctx.Int32Type(), 0, false),
low,
}
slicePtr := c.builder.CreateGEP(value, indices, "slice.ptr")
sliceLen := c.builder.CreateSub(high, low, "slice.len")
sliceCap := c.builder.CreateSub(llvmLenInt, low, "slice.cap")
// This check is optimized away in most cases.
c.emitSliceBoundsCheck(frame, llvmLen, low, high)
if c.targetData.TypeAllocSize(sliceLen.Type()) > c.targetData.TypeAllocSize(c.lenType) {
sliceLen = c.builder.CreateTrunc(sliceLen, c.lenType, "")
sliceCap = c.builder.CreateTrunc(sliceCap, c.lenType, "")
}
slice := c.ctx.ConstStruct([]llvm.Value{
llvm.Undef(slicePtr.Type()),
llvm.Undef(c.lenType),
llvm.Undef(c.lenType),
}, 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, oldLen, low, high)
if c.targetData.TypeAllocSize(low.Type()) > c.targetData.TypeAllocSize(c.lenType) {
low = c.builder.CreateTrunc(low, c.lenType, "")
}
if c.targetData.TypeAllocSize(high.Type()) > c.targetData.TypeAllocSize(c.lenType) {
high = c.builder.CreateTrunc(high, c.lenType, "")
}
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.lenType),
llvm.Undef(c.lenType),
}, 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{}, errors.New("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)
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{}, errors.New("unknown slice type: " + typ.String())
}
case *ssa.TypeAssert:
itf, err := c.parseExpr(frame, expr.X)
if err != nil {
return llvm.Value{}, err
}
assertedType, err := c.getLLVMType(expr.AssertedType)
if err != nil {
return llvm.Value{}, err
}
valueNil, err := c.getZeroValue(assertedType)
if err != nil {
return llvm.Value{}, err
}
actualTypeNum := c.builder.CreateExtractValue(itf, 0, "interface.type")
commaOk := llvm.Value{}
if itf, ok := expr.AssertedType.Underlying().(*types.Interface); ok {
// Type assert on interface type.
// This is slightly non-trivial: at runtime the list of methods
// needs to be checked to see whether it implements the interface.
// At the same time, the interface value itself is unchanged.
itfTypeNum := c.ir.InterfaceNum(itf)
itfTypeNumValue := llvm.ConstInt(c.ctx.Int16Type(), uint64(itfTypeNum), false)
commaOk = c.createRuntimeCall("interfaceImplements", []llvm.Value{actualTypeNum, itfTypeNumValue}, "")
} else {
// Type assert on concrete type.
// This is easy: just compare the type number.
assertedTypeNum, typeExists := c.ir.TypeNum(expr.AssertedType)
if !typeExists {
// Static analysis has determined this type assert will never apply.
// Using undef here so that LLVM knows we'll never get here and
// can optimize accordingly.
undef := llvm.Undef(assertedType)
commaOk := llvm.ConstInt(c.ctx.Int1Type(), 0, false)
if expr.CommaOk {
return c.ctx.ConstStruct([]llvm.Value{undef, commaOk}, false), nil
} else {
c.createRuntimeCall("interfaceTypeAssert", []llvm.Value{commaOk}, "")
return undef, nil
}
}
if assertedTypeNum >= 1<<16 {
return llvm.Value{}, errors.New("interface typecodes do not fit in a 16-bit integer")
}
assertedTypeNumValue := llvm.ConstInt(c.ctx.Int16Type(), uint64(assertedTypeNum), false)
commaOk = c.builder.CreateICmp(llvm.IntEQ, assertedTypeNumValue, actualTypeNum, "")
}
// Add 2 new basic blocks (that should get optimized away): one for the
// 'ok' case and one for all instructions following this type assert.
// This is necessary because we need to insert the casted value or the
// nil value based on whether the assert was successful. Casting before
// this check tells LLVM that it can use this value and may
// speculatively dereference pointers before the check. This can lead to
// a miscompilation resulting in a segfault at runtime.
// Additionally, this is even required by the Go spec: a failed
// typeassert should return a zero value, not an incorrectly casted
// value.
prevBlock := c.builder.GetInsertBlock()
okBlock := c.ctx.AddBasicBlock(frame.fn.LLVMFn, "typeassert.ok")
nextBlock := c.ctx.AddBasicBlock(frame.fn.LLVMFn, "typeassert.next")
frame.blockExits[frame.currentBlock] = nextBlock // adjust outgoing block for phi nodes
c.builder.CreateCondBr(commaOk, okBlock, nextBlock)
// Retrieve the value from the interface if the type assert was
// successful.
c.builder.SetInsertPointAtEnd(okBlock)
var valueOk llvm.Value
if _, ok := expr.AssertedType.Underlying().(*types.Interface); ok {
// Type assert on interface type. Easy: just return the same
// interface value.
valueOk = itf
} else {
// Type assert on concrete type. Extract the underlying type from
// the interface (but only after checking it matches).
valuePtr := c.builder.CreateExtractValue(itf, 1, "typeassert.value.ptr")
if c.targetData.TypeAllocSize(assertedType) > c.targetData.TypeAllocSize(c.i8ptrType) {
// Value was stored in an allocated buffer, load it from there.
valuePtrCast := c.builder.CreateBitCast(valuePtr, llvm.PointerType(assertedType, 0), "")
valueOk = c.builder.CreateLoad(valuePtrCast, "typeassert.value.ok")
} else {
// Value was stored directly in the interface.
switch assertedType.TypeKind() {
case llvm.IntegerTypeKind:
valueOk = c.builder.CreatePtrToInt(valuePtr, assertedType, "typeassert.value.ok")
case llvm.PointerTypeKind:
valueOk = c.builder.CreateBitCast(valuePtr, assertedType, "typeassert.value.ok")
case llvm.StructTypeKind:
// A bitcast would be useful here, but bitcast doesn't allow
// aggregate types. So we'll bitcast it using an alloca.
// Hopefully this will get optimized away.
mem := c.builder.CreateAlloca(c.i8ptrType, "")
c.builder.CreateStore(valuePtr, mem)
memStructPtr := c.builder.CreateBitCast(mem, llvm.PointerType(assertedType, 0), "")
valueOk = c.builder.CreateLoad(memStructPtr, "typeassert.value.ok")
default:
return llvm.Value{}, errors.New("todo: typeassert: bitcast small types")
}
}
}
c.builder.CreateBr(nextBlock)
// Continue after the if statement.
c.builder.SetInsertPointAtEnd(nextBlock)
phi := c.builder.CreatePHI(assertedType, "typeassert.value")
phi.AddIncoming([]llvm.Value{valueNil, valueOk}, []llvm.BasicBlock{prevBlock, okBlock})
if expr.CommaOk {
tuple := c.ctx.ConstStruct([]llvm.Value{llvm.Undef(assertedType), llvm.Undef(c.ctx.Int1Type())}, false) // create empty tuple
tuple = c.builder.CreateInsertValue(tuple, phi, 0, "") // insert value
tuple = c.builder.CreateInsertValue(tuple, commaOk, 1, "") // insert 'comma ok' boolean
return tuple, nil
} else {
// This is kind of dirty as the branch above becomes mostly useless,
// but hopefully this gets optimized away.
c.createRuntimeCall("interfaceTypeAssert", []llvm.Value{commaOk}, "")
return phi, nil
}
case *ssa.UnOp:
return c.parseUnOp(frame, expr)
default:
return llvm.Value{}, errors.New("todo: unknown expression: " + expr.String())
}
}
func (c *Compiler) parseBinOp(op token.Token, typ types.Type, x, y llvm.Value) (llvm.Value, error) {
switch typ := typ.(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:
return llvm.Value{}, errors.New("todo: 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.REM: // %
return c.builder.CreateFRem(x, y, ""), nil
case token.EQL: // ==
return c.builder.CreateFCmp(llvm.FloatOEQ, x, y, ""), nil
case token.NEQ: // !=
return c.builder.CreateFCmp(llvm.FloatONE, x, y, ""), nil
case token.LSS: // <
return c.builder.CreateFCmp(llvm.FloatOLT, x, y, ""), nil
case token.LEQ: // <=
return c.builder.CreateFCmp(llvm.FloatOLE, x, y, ""), nil
case token.GTR: // >
return c.builder.CreateFCmp(llvm.FloatOGT, x, y, ""), nil
case token.GEQ: // >=
return c.builder.CreateFCmp(llvm.FloatOGE, x, y, ""), nil
default:
return llvm.Value{}, errors.New("todo: binop on float: " + 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:
return llvm.Value{}, errors.New("todo: binop on boolean: " + 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:
return llvm.Value{}, errors.New("todo: 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, token.NEQ: // ==, !=
result := c.createRuntimeCall("stringEqual", []llvm.Value{x, y}, "")
if op == token.NEQ {
result = c.builder.CreateNot(result, "")
}
return result, nil
default:
return llvm.Value{}, errors.New("todo: binop on string: " + op.String())
}
} else {
return llvm.Value{}, errors.New("todo: unknown basic type in binop: " + typ.String())
}
case *types.Signature:
if c.ir.SignatureNeedsContext(typ) {
// This is a closure, not a function pointer. Get the underlying
// function pointer.
// This is safe: function pointers are generally not comparable
// against each other, only against nil. So one or both has to be
// nil, so we can ignore the contents of the closure.
x = c.builder.CreateExtractValue(x, 1, "")
y = c.builder.CreateExtractValue(y, 1, "")
}
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{}, errors.New("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{}, errors.New("binop on interface: " + op.String())
}
case *types.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{}, errors.New("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{}, errors.New("todo: binop on slice: " + 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)
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{}, errors.New("unknown: binop on struct: " + op.String())
}
return result, nil
default:
return llvm.Value{}, errors.New("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.lenType, 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.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(llvm.VectorType(c.ctx.DoubleType(), 2))
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.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.ctx.Int16Type(), 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.lenType, 0, false)
slice := c.ctx.ConstStruct([]llvm.Value{
llvmPtr, // backing array
llvmLen, // len
llvmLen, // cap
}, false)
return slice, nil
default:
return llvm.Value{}, errors.New("todo: unknown constant: " + expr.String())
}
}
func (c *Compiler) parseConvert(typeFrom, typeTo types.Type, value llvm.Value) (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 {
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{}, errors.New("todo: convert to string: " + typeFrom.String())
}
default:
return llvm.Value{}, errors.New("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 typeTo.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 { // to signed int
return c.builder.CreateFPToSI(value, llvmTypeTo, ""), nil
} else { // to unsigned int
return c.builder.CreateFPToUI(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 { // from signed int
return c.builder.CreateSIToFP(value, llvmTypeTo, ""), nil
} else { // from unsigned int
return c.builder.CreateUIToFP(value, llvmTypeTo, ""), nil
}
}
if typeFrom.Kind() == types.Complex128 && typeTo.Kind() == types.Complex64 {
// Conversion from complex128 to complex64.
r := c.builder.CreateExtractElement(value, llvm.ConstInt(c.ctx.Int32Type(), 0, false), "real.f64")
i := c.builder.CreateExtractElement(value, llvm.ConstInt(c.ctx.Int32Type(), 1, false), "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(llvm.VectorType(c.ctx.FloatType(), 2))
cplx = c.builder.CreateInsertElement(cplx, r, llvm.ConstInt(c.ctx.Int8Type(), 0, false), "")
cplx = c.builder.CreateInsertElement(cplx, i, llvm.ConstInt(c.ctx.Int8Type(), 1, false), "")
return cplx, nil
}
if typeFrom.Kind() == types.Complex64 && typeTo.Kind() == types.Complex128 {
// Conversion from complex64 to complex128.
r := c.builder.CreateExtractElement(value, llvm.ConstInt(c.ctx.Int32Type(), 0, false), "real.f32")
i := c.builder.CreateExtractElement(value, llvm.ConstInt(c.ctx.Int32Type(), 1, false), "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(llvm.VectorType(c.ctx.DoubleType(), 2))
cplx = c.builder.CreateInsertElement(cplx, r, llvm.ConstInt(c.ctx.Int8Type(), 0, false), "")
cplx = c.builder.CreateInsertElement(cplx, i, llvm.ConstInt(c.ctx.Int8Type(), 1, false), "")
return cplx, nil
}
return llvm.Value{}, errors.New("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{}, errors.New("todo: convert from string: " + elemType.String())
}
default:
return llvm.Value{}, errors.New("todo: convert " + typeTo.String() + " <- " + typeFrom.String())
}
}
func (c *Compiler) parseMakeClosure(frame *Frame, expr *ssa.MakeClosure) (llvm.Value, error) {
if len(expr.Bindings) == 0 {
panic("unexpected: MakeClosure without bound variables")
}
f := c.ir.GetFunction(expr.Fn.(*ssa.Function))
if !c.ir.FunctionNeedsContext(f) {
// Maybe AnalyseFunctionPointers didn't run?
panic("MakeClosure on function signature without context")
}
// Collect all bound variables.
boundVars := make([]llvm.Value, 0, len(expr.Bindings))
boundVarTypes := make([]llvm.Type, 0, len(expr.Bindings))
for _, binding := range expr.Bindings {
// The context stores the bound variables.
llvmBoundVar, err := c.parseExpr(frame, binding)
if err != nil {
return llvm.Value{}, err
}
boundVars = append(boundVars, llvmBoundVar)
boundVarTypes = append(boundVarTypes, llvmBoundVar.Type())
}
contextType := c.ctx.StructType(boundVarTypes, false)
// Allocate memory for the context.
contextAlloc := llvm.Value{}
contextHeapAlloc := llvm.Value{}
if c.targetData.TypeAllocSize(contextType) <= c.targetData.TypeAllocSize(c.i8ptrType) {
// Context fits in a pointer - e.g. when it is a pointer. Store it
// directly in the stack after a convert.
// Because contextType is a struct and we have to cast it to a *i8,
// store it in an alloca first for bitcasting (store+bitcast+load).
contextAlloc = c.builder.CreateAlloca(contextType, "")
} else {
// Context is bigger than a pointer, so allocate it on the heap.
size := c.targetData.TypeAllocSize(contextType)
sizeValue := llvm.ConstInt(c.uintptrType, size, false)
contextHeapAlloc = c.createRuntimeCall("alloc", []llvm.Value{sizeValue}, "")
contextAlloc = c.builder.CreateBitCast(contextHeapAlloc, llvm.PointerType(contextType, 0), "")
}
// Store all bound variables in the alloca or heap pointer.
for i, boundVar := range boundVars {
indices := []llvm.Value{
llvm.ConstInt(c.ctx.Int32Type(), 0, false),
llvm.ConstInt(c.ctx.Int32Type(), uint64(i), false),
}
gep := c.builder.CreateInBoundsGEP(contextAlloc, indices, "")
c.builder.CreateStore(boundVar, gep)
}
context := llvm.Value{}
if c.targetData.TypeAllocSize(contextType) <= c.targetData.TypeAllocSize(c.i8ptrType) {
// Load value (as *i8) from the alloca.
contextAlloc = c.builder.CreateBitCast(contextAlloc, llvm.PointerType(c.i8ptrType, 0), "")
context = c.builder.CreateLoad(contextAlloc, "")
} else {
// Get the original heap allocation pointer, which already is an
// *i8.
context = contextHeapAlloc
}
// Get the function signature type, which is a closure type.
// A closure is a tuple of {context, function pointer}.
typ, err := c.getLLVMType(f.Signature)
if err != nil {
return llvm.Value{}, err
}
// Create the closure, which is a struct: {context, function pointer}.
closure, err := c.getZeroValue(typ)
if err != nil {
return llvm.Value{}, err
}
closure = c.builder.CreateInsertValue(closure, f.LLVMFn, 1, "")
closure = c.builder.CreateInsertValue(closure, context, 0, "")
return closure, nil
}
func (c *Compiler) parseMakeInterface(val llvm.Value, typ types.Type, global string) (llvm.Value, error) {
var itfValue llvm.Value
size := c.targetData.TypeAllocSize(val.Type())
if size > c.targetData.TypeAllocSize(c.i8ptrType) {
if global != "" {
// Allocate in a global variable.
global := llvm.AddGlobal(c.mod, val.Type(), global+"$itfvalue")
global.SetInitializer(val)
global.SetLinkage(llvm.InternalLinkage)
global.SetGlobalConstant(true)
zero := llvm.ConstInt(c.ctx.Int32Type(), 0, false)
itfValueRaw := llvm.ConstInBoundsGEP(global, []llvm.Value{zero, zero})
itfValue = llvm.ConstBitCast(itfValueRaw, c.i8ptrType)
} else {
// Allocate on the heap and put a pointer in the interface.
// TODO: escape analysis.
sizeValue := llvm.ConstInt(c.uintptrType, size, false)
itfValue = c.createRuntimeCall("alloc", []llvm.Value{sizeValue}, "")
itfValueCast := c.builder.CreateBitCast(itfValue, llvm.PointerType(val.Type(), 0), "")
c.builder.CreateStore(val, itfValueCast)
}
} else {
// Directly place the value in the interface.
switch val.Type().TypeKind() {
case llvm.IntegerTypeKind:
itfValue = c.builder.CreateIntToPtr(val, c.i8ptrType, "")
case llvm.PointerTypeKind:
itfValue = c.builder.CreateBitCast(val, c.i8ptrType, "")
case llvm.StructTypeKind:
// A bitcast would be useful here, but bitcast doesn't allow
// aggregate types. So we'll bitcast it using an alloca.
// Hopefully this will get optimized away.
mem := c.builder.CreateAlloca(c.i8ptrType, "")
memStructPtr := c.builder.CreateBitCast(mem, llvm.PointerType(val.Type(), 0), "")
c.builder.CreateStore(val, memStructPtr)
itfValue = c.builder.CreateLoad(mem, "")
default:
return llvm.Value{}, errors.New("todo: makeinterface: cast small type to i8*")
}
}
itfTypeNum, _ := c.ir.TypeNum(typ)
if itfTypeNum >= 1<<16 {
return llvm.Value{}, errors.New("interface typecodes do not fit in a 16-bit integer")
}
itf := llvm.ConstNamedStruct(c.mod.GetTypeByName("runtime._interface"), []llvm.Value{llvm.ConstInt(c.ctx.Int16Type(), uint64(itfTypeNum), false), llvm.Undef(c.i8ptrType)})
itf = c.builder.CreateInsertValue(itf, itfValue, 1, "")
return itf, nil
}
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{}, errors.New("todo: unknown basic type for negate: " + typ.String())
}
} else {
return llvm.Value{}, errors.New("todo: unknown type for negate: " + unop.X.Type().Underlying().String())
}
case token.MUL: // *x, dereference pointer
valType := unop.X.Type().(*types.Pointer).Elem()
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
default:
return llvm.Value{}, errors.New("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, 0)
}
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)
}
}
// 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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