Golang llvm.ConstBitCast函數代碼示例

func (tm *TypeMap) interfaceRuntimeType(i *types.Interface) (global, ptr llvm.Value) {
	rtype := tm.makeRtype(i, reflect.Interface)
	interfaceType := llvm.ConstNull(tm.runtime.interfaceType.llvm)
	global, ptr = tm.makeRuntimeTypeGlobal(interfaceType, typeString(i))
	tm.types.Set(i, runtimeTypeInfo{global, ptr})
	interfaceType = llvm.ConstInsertValue(interfaceType, rtype, []uint32{0})
	methodset := tm.MethodSet(i)
	imethods := make([]llvm.Value, methodset.Len())
	for index := 0; index < methodset.Len(); index++ {
		method := methodset.At(index).Obj()
		imethod := llvm.ConstNull(tm.runtime.imethod.llvm)
		name := tm.globalStringPtr(method.Name())
		name = llvm.ConstBitCast(name, tm.runtime.imethod.llvm.StructElementTypes()[0])
		mtyp := tm.ToRuntime(method.Type())
		imethod = llvm.ConstInsertValue(imethod, name, []uint32{0})
		if !ast.IsExported(method.Name()) {
			pkgpath := tm.globalStringPtr(method.Pkg().Path())
			pkgpath = llvm.ConstBitCast(pkgpath, tm.runtime.imethod.llvm.StructElementTypes()[1])
			imethod = llvm.ConstInsertValue(imethod, pkgpath, []uint32{1})
		}
		imethod = llvm.ConstInsertValue(imethod, mtyp, []uint32{2})
		imethods[index] = imethod
	}
	imethodsSliceType := tm.runtime.interfaceType.llvm.StructElementTypes()[1]
	imethodsSlice := tm.makeSlice(imethods, imethodsSliceType)
	interfaceType = llvm.ConstInsertValue(interfaceType, imethodsSlice, []uint32{1})
	global.SetInitializer(interfaceType)
	return global, ptr
}

func (tm *TypeMap) interfaceRuntimeType(tstr string, i *types.Interface) (global, ptr llvm.Value) {
	rtype := tm.makeRtype(i, reflect.Interface)
	interfaceType := llvm.ConstNull(tm.runtimeInterfaceType)
	global, ptr = tm.makeRuntimeTypeGlobal(interfaceType)
	tm.types.record(tstr, global, ptr)
	interfaceType = llvm.ConstInsertValue(interfaceType, rtype, []uint32{0})
	methodset := i.MethodSet()
	imethods := make([]llvm.Value, methodset.Len())
	for index := 0; index < methodset.Len(); index++ {
		method := methodset.At(index).Obj()
		imethod := llvm.ConstNull(tm.runtimeImethod)
		name := tm.globalStringPtr(method.Name())
		name = llvm.ConstBitCast(name, tm.runtimeImethod.StructElementTypes()[0])
		//pkgpath := tm.globalStringPtr(tm.functions.objectdata[method].Package.Path())
		//pkgpath = llvm.ConstBitCast(name, tm.runtimeImethod.StructElementTypes()[1])
		mtyp := tm.ToRuntime(method.Type())
		imethod = llvm.ConstInsertValue(imethod, name, []uint32{0})
		//imethod = llvm.ConstInsertValue(imethod, pkgpath, []uint32{1})
		imethod = llvm.ConstInsertValue(imethod, mtyp, []uint32{2})
		imethods[index] = imethod
	}
	imethodsSliceType := tm.runtimeInterfaceType.StructElementTypes()[1]
	imethodsSlice := tm.makeSlice(imethods, imethodsSliceType)
	interfaceType = llvm.ConstInsertValue(interfaceType, imethodsSlice, []uint32{1})
	global.SetInitializer(interfaceType)
	return global, ptr
}

func (tm *TypeMap) uncommonType(n *types.Named, ptr bool) llvm.Value {
	uncommonTypeInit := llvm.ConstNull(tm.runtimeUncommonType)
	namePtr := tm.globalStringPtr(n.Obj().Name())
	uncommonTypeInit = llvm.ConstInsertValue(uncommonTypeInit, namePtr, []uint32{0})

	_, path := tm.qualifiedName(n)
	pkgpathPtr := tm.globalStringPtr(path)
	uncommonTypeInit = llvm.ConstInsertValue(uncommonTypeInit, pkgpathPtr, []uint32{1})

	methodset := tm.functions.methods(n)
	methodfuncs := methodset.nonptr
	if ptr {
		methodfuncs = methodset.ptr
	}

	// Store methods.
	methods := make([]llvm.Value, len(methodfuncs))
	for i, mfunc := range methodfuncs {
		ftyp := mfunc.Type().(*types.Signature)

		method := llvm.ConstNull(tm.runtimeMethod)
		name := tm.globalStringPtr(mfunc.Name())
		name = llvm.ConstBitCast(name, tm.runtimeMethod.StructElementTypes()[0])
		// name
		method = llvm.ConstInsertValue(method, name, []uint32{0})
		// pkgPath
		method = llvm.ConstInsertValue(method, pkgpathPtr, []uint32{1})
		// mtyp (method type, no receiver)
		{
			ftyp := types.NewSignature(nil, nil, ftyp.Params(), ftyp.Results(), ftyp.IsVariadic())
			mtyp := tm.ToRuntime(ftyp)
			method = llvm.ConstInsertValue(method, mtyp, []uint32{2})
		}
		// typ (function type, with receiver)
		typ := tm.ToRuntime(ftyp)
		method = llvm.ConstInsertValue(method, typ, []uint32{3})

		// tfn (standard method/function pointer for plain method calls)
		tfn := tm.resolver.Resolve(tm.functions.objectdata[mfunc].Ident).LLVMValue()
		tfn = llvm.ConstExtractValue(tfn, []uint32{0})
		tfn = llvm.ConstPtrToInt(tfn, tm.target.IntPtrType())

		// ifn (single-word receiver function pointer for interface calls)
		ifn := tfn
		if !ptr && tm.Sizeof(ftyp.Recv().Type()) > int64(tm.target.PointerSize()) {
			mfunc := methodset.lookup(mfunc.Name(), true)
			ifn = tm.resolver.Resolve(tm.functions.objectdata[mfunc].Ident).LLVMValue()
			ifn = llvm.ConstExtractValue(ifn, []uint32{0})
			ifn = llvm.ConstPtrToInt(ifn, tm.target.IntPtrType())
		}

		method = llvm.ConstInsertValue(method, ifn, []uint32{4})
		method = llvm.ConstInsertValue(method, tfn, []uint32{5})
		methods[i] = method
	}
	methodsSliceType := tm.runtimeUncommonType.StructElementTypes()[2]
	methodsSlice := tm.makeSlice(methods, methodsSliceType)
	uncommonTypeInit = llvm.ConstInsertValue(uncommonTypeInit, methodsSlice, []uint32{2})
	return uncommonTypeInit
}

func (tm *TypeMap) makeRuntimeTypeGlobal(v llvm.Value, name string) (global, ptr llvm.Value) {
	global = llvm.AddGlobal(tm.module, v.Type(), typeSymbol(name))
	global.SetInitializer(v)
	global.SetLinkage(llvm.LinkOnceAnyLinkage)
	ptr = llvm.ConstBitCast(global, llvm.PointerType(tm.runtime.rtype.llvm, 0))
	return global, ptr
}

func (tm *TypeMap) nameRuntimeType(n *types.Named) (global, ptr llvm.Value) {
	name := typeString(n)
	path := "runtime"
	if pkg := n.Obj().Pkg(); pkg != nil {
		path = pkg.Path()
	}
	if path != tm.pkgpath {
		// We're not compiling the package from whence the type came,
		// so we'll just create a pointer to it here.
		global := llvm.AddGlobal(tm.module, tm.runtime.rtype.llvm, typeSymbol(name))
		global.SetInitializer(llvm.ConstNull(tm.runtime.rtype.llvm))
		global.SetLinkage(llvm.CommonLinkage)
		return global, global
	}

	// If the underlying type is Basic, then we always create
	// a new global. Otherwise, we clone the value returned
	// from toRuntime in case it is cached and reused.
	underlying := n.Underlying()
	if basic, ok := underlying.(*types.Basic); ok {
		global, ptr = tm.basicRuntimeType(basic, true)
		global.SetName(typeSymbol(name))
	} else {
		global, ptr = tm.toRuntime(underlying)
		clone := llvm.AddGlobal(tm.module, global.Type().ElementType(), typeSymbol(name))
		clone.SetInitializer(global.Initializer())
		global = clone
		ptr = llvm.ConstBitCast(global, llvm.PointerType(tm.runtime.rtype.llvm, 0))
	}
	global.SetLinkage(llvm.ExternalLinkage)

	// Locate the rtype.
	underlyingRuntimeType := global.Initializer()
	rtype := underlyingRuntimeType
	if rtype.Type() != tm.runtime.rtype.llvm {
		rtype = llvm.ConstExtractValue(rtype, []uint32{0})
	}

	// Insert the uncommon type.
	uncommonTypeInit := tm.uncommonType(n, nil)
	uncommonType := llvm.AddGlobal(tm.module, uncommonTypeInit.Type(), "")
	uncommonType.SetInitializer(uncommonTypeInit)
	rtype = llvm.ConstInsertValue(rtype, uncommonType, []uint32{9})

	// Replace the rtype's string representation with the one from
	// uncommonType. XXX should we have the package name prepended? Probably.
	namePtr := llvm.ConstExtractValue(uncommonTypeInit, []uint32{0})
	rtype = llvm.ConstInsertValue(rtype, namePtr, []uint32{8})

	// Update the global's initialiser. Note that we take a copy
	// of the underlying type; we're not updating a shared type.
	if underlyingRuntimeType.Type() != tm.runtime.rtype.llvm {
		underlyingRuntimeType = llvm.ConstInsertValue(underlyingRuntimeType, rtype, []uint32{0})
	} else {
		underlyingRuntimeType = rtype
	}
	global.SetInitializer(underlyingRuntimeType)
	return global, ptr
}

func (tm *TypeMap) makeRuntimeTypeGlobal(v llvm.Value) (global, ptr llvm.Value) {
	// Each runtime type is preceded by an interface{}.
	initType := llvm.StructType([]llvm.Type{tm.runtimeType, v.Type()}, false)
	global = llvm.AddGlobal(tm.module, initType, "")
	ptr = llvm.ConstBitCast(global, llvm.PointerType(tm.runtimeType, 0))

	// interface{} containing v's *commonType representation.
	runtimeTypeValue := llvm.Undef(tm.runtimeType)
	zero := llvm.ConstNull(llvm.Int32Type())
	one := llvm.ConstInt(llvm.Int32Type(), 1, false)
	i8ptr := llvm.PointerType(llvm.Int8Type(), 0)
	if tm.commonTypePtrRuntimeType.IsNil() {
		// Create a dummy pointer value, which we'll update straight after
		// defining the runtime type info for commonType.
		tm.commonTypePtrRuntimeType = llvm.Undef(i8ptr)
		commonTypePtr := &types.Pointer{Base: tm.commonType}
		commonTypeGlobal, commonTypeRuntimeType := tm.makeRuntimeType(tm.commonType)
		tm.types[tm.commonType.String()] = runtimeTypeInfo{commonTypeGlobal, commonTypeRuntimeType}
		commonTypePtrGlobal, commonTypePtrRuntimeType := tm.makeRuntimeType(commonTypePtr)
		tm.types[commonTypePtr.String()] = runtimeTypeInfo{commonTypePtrGlobal, commonTypePtrRuntimeType}
		tm.commonTypePtrRuntimeType = llvm.ConstBitCast(commonTypePtrRuntimeType, i8ptr)
		if tm.pkgpath == tm.commonType.Package {
			// Update the interace{} header of the commonType/*commonType
			// runtime types we just created.
			for _, g := range [...]llvm.Value{commonTypeGlobal, commonTypePtrGlobal} {
				init := g.Initializer()
				typptr := tm.commonTypePtrRuntimeType
				runtimeTypeValue := llvm.ConstExtractValue(init, []uint32{0})
				runtimeTypeValue = llvm.ConstInsertValue(runtimeTypeValue, typptr, []uint32{0})
				init = llvm.ConstInsertValue(init, runtimeTypeValue, []uint32{0})
				g.SetInitializer(init)
			}
		}
	}
	commonTypePtr := llvm.ConstGEP(global, []llvm.Value{zero, one})
	commonTypePtr = llvm.ConstBitCast(commonTypePtr, i8ptr)
	runtimeTypeValue = llvm.ConstInsertValue(runtimeTypeValue, tm.commonTypePtrRuntimeType, []uint32{0})
	runtimeTypeValue = llvm.ConstInsertValue(runtimeTypeValue, commonTypePtr, []uint32{1})

	init := llvm.Undef(initType)
	init = llvm.ConstInsertValue(init, runtimeTypeValue, []uint32{0})
	init = llvm.ConstInsertValue(init, v, []uint32{1})
	global.SetInitializer(init)

	return global, ptr
}

func (tm *TypeMap) basicRuntimeType(b *types.Basic) llvm.Value {
	commonType := tm.makeCommonType(b, reflect.Kind(b.Kind))
	result := llvm.AddGlobal(tm.module, commonType.Type(), "")
	elementTypes := tm.runtimeCommonType.StructElementTypes()
	ptr := llvm.ConstBitCast(result, elementTypes[9])
	commonType = llvm.ConstInsertValue(commonType, ptr, []uint32{9})
	result.SetInitializer(commonType)
	return result
}

func (tm *TypeMap) structRuntimeType(s *types.Struct) (global, ptr llvm.Value) {
	rtype := tm.makeRtype(s, reflect.Struct)
	structType := llvm.ConstNull(tm.runtime.structType.llvm)
	structType = llvm.ConstInsertValue(structType, rtype, []uint32{0})
	global, ptr = tm.makeRuntimeTypeGlobal(structType, typeString(s))
	tm.types.Set(s, runtimeTypeInfo{global, ptr})
	fieldVars := make([]*types.Var, s.NumFields())
	for i := range fieldVars {
		fieldVars[i] = s.Field(i)
	}
	offsets := tm.Offsetsof(fieldVars)
	structFields := make([]llvm.Value, len(fieldVars))
	for i := range structFields {
		field := fieldVars[i]
		structField := llvm.ConstNull(tm.runtime.structField.llvm)
		if !field.Anonymous() {
			name := tm.globalStringPtr(field.Name())
			name = llvm.ConstBitCast(name, tm.runtime.structField.llvm.StructElementTypes()[0])
			structField = llvm.ConstInsertValue(structField, name, []uint32{0})
		}
		if !ast.IsExported(field.Name()) {
			pkgpath := tm.globalStringPtr(field.Pkg().Path())
			pkgpath = llvm.ConstBitCast(pkgpath, tm.runtime.structField.llvm.StructElementTypes()[1])
			structField = llvm.ConstInsertValue(structField, pkgpath, []uint32{1})
		}
		fieldType := tm.ToRuntime(field.Type())
		structField = llvm.ConstInsertValue(structField, fieldType, []uint32{2})
		if tag := s.Tag(i); tag != "" {
			tag := tm.globalStringPtr(tag)
			tag = llvm.ConstBitCast(tag, tm.runtime.structField.llvm.StructElementTypes()[3])
			structField = llvm.ConstInsertValue(structField, tag, []uint32{3})
		}
		offset := llvm.ConstInt(tm.runtime.structField.llvm.StructElementTypes()[4], uint64(offsets[i]), false)
		structField = llvm.ConstInsertValue(structField, offset, []uint32{4})
		structFields[i] = structField
	}
	structFieldsSliceType := tm.runtime.structType.llvm.StructElementTypes()[1]
	structFieldsSlice := tm.makeSlice(structFields, structFieldsSliceType)
	structType = llvm.ConstInsertValue(structType, structFieldsSlice, []uint32{1})
	global.SetInitializer(structType)
	return global, ptr
}

// globalStringPtr returns a *string with the specified value.
func (tm *TypeMap) globalStringPtr(value string) llvm.Value {
	strval := llvm.ConstString(value, false)
	strglobal := llvm.AddGlobal(tm.module, strval.Type(), "")
	strglobal.SetInitializer(strval)
	strglobal = llvm.ConstBitCast(strglobal, llvm.PointerType(llvm.Int8Type(), 0))
	strlen := llvm.ConstInt(tm.inttype, uint64(len(value)), false)
	str := llvm.ConstStruct([]llvm.Value{strglobal, strlen}, false)
	g := llvm.AddGlobal(tm.module, str.Type(), "")
	g.SetInitializer(str)
	return g
}

func (tm *TypeMap) interfaceRuntimeType(i *types.Interface) (global, ptr llvm.Value) {
	rtype := tm.makeRtype(i, reflect.Interface)
	interfaceType := llvm.ConstNull(tm.runtimeInterfaceType)
	interfaceType = llvm.ConstInsertValue(interfaceType, rtype, []uint32{0})

	imethods := make([]llvm.Value, i.NumMethods())
	for index := range imethods {
		method := i.Method(index)

		//name, pkgPath, type
		imethod := llvm.ConstNull(tm.runtimeImethod)
		name := tm.globalStringPtr(method.Name())
		name = llvm.ConstBitCast(name, tm.runtimeImethod.StructElementTypes()[0])

		imethod = llvm.ConstInsertValue(imethod, name, []uint32{0})
		//imethod = llvm.ConstInsertValue(imethod, , []uint32{1})
		//imethod = llvm.ConstInsertValue(imethod, , []uint32{2})
		imethods[index] = imethod
	}

	var imethodsGlobalPtr llvm.Value
	imethodPtrType := llvm.PointerType(tm.runtimeImethod, 0)
	if len(imethods) > 0 {
		imethodsArray := llvm.ConstArray(tm.runtimeImethod, imethods)
		imethodsGlobalPtr = llvm.AddGlobal(tm.module, imethodsArray.Type(), "")
		imethodsGlobalPtr.SetInitializer(imethodsArray)
		imethodsGlobalPtr = llvm.ConstBitCast(imethodsGlobalPtr, imethodPtrType)
	} else {
		imethodsGlobalPtr = llvm.ConstNull(imethodPtrType)
	}

	len_ := llvm.ConstInt(tm.inttype, uint64(i.NumMethods()), false)
	imethodsSliceType := tm.runtimeInterfaceType.StructElementTypes()[1]
	imethodsSlice := llvm.ConstNull(imethodsSliceType)
	imethodsSlice = llvm.ConstInsertValue(imethodsSlice, imethodsGlobalPtr, []uint32{0})
	imethodsSlice = llvm.ConstInsertValue(imethodsSlice, len_, []uint32{1})
	imethodsSlice = llvm.ConstInsertValue(imethodsSlice, len_, []uint32{2})
	interfaceType = llvm.ConstInsertValue(interfaceType, imethodsSlice, []uint32{1})
	return tm.makeRuntimeTypeGlobal(interfaceType)
}

func (tm *TypeMap) mapRuntimeType(m *types.Map) llvm.Value {
	result := llvm.AddGlobal(tm.module, tm.runtimeMapType, "")
	elementTypes := tm.runtimeCommonType.StructElementTypes()
	ptr := llvm.ConstBitCast(result, elementTypes[9])
	commonType := tm.makeCommonType(m, reflect.Map)
	commonType = llvm.ConstInsertValue(commonType, ptr, []uint32{9})

	init := llvm.ConstNull(tm.runtimeMapType)
	init = llvm.ConstInsertValue(init, commonType, []uint32{0})
	result.SetInitializer(init)

	// TODO set key, elem

	return result
}

func (tm *TypeMap) structRuntimeType(s *types.Struct) llvm.Value {
	result := llvm.AddGlobal(tm.module, tm.runtimeStructType, "")
	elementTypes := tm.runtimeCommonType.StructElementTypes()
	ptr := llvm.ConstBitCast(result, elementTypes[9])
	commonType := tm.makeCommonType(s, reflect.Struct)
	commonType = llvm.ConstInsertValue(commonType, ptr, []uint32{9})

	init := llvm.ConstNull(tm.runtimeStructType)
	init = llvm.ConstInsertValue(init, commonType, []uint32{0})
	result.SetInitializer(init)

	// TODO set fields

	//panic("unimplemented")
	return result
}

func (tm *TypeMap) nameRuntimeType(n *types.Name) llvm.Value {
	underlyingRuntimeType := tm.ToRuntime(n.Underlying).Initializer()
	result := llvm.AddGlobal(tm.module, underlyingRuntimeType.Type(), "")
	result.SetName("__llgo.reflect." + n.Obj.Name)
	elementTypes := tm.runtimeCommonType.StructElementTypes()
	ptr := llvm.ConstBitCast(result, elementTypes[9])
	commonType := llvm.ConstInsertValue(underlyingRuntimeType, ptr, []uint32{9})

	uncommonTypeInit := llvm.ConstNull(tm.runtimeUncommonType) // TODO
	uncommonType := llvm.AddGlobal(tm.module, uncommonTypeInit.Type(), "")
	uncommonType.SetInitializer(uncommonTypeInit)
	commonType = llvm.ConstInsertValue(commonType, uncommonType, []uint32{8})

	// TODO set string, uncommonType.
	result.SetInitializer(commonType)
	return result
}

func (tm *TypeMap) makeSlice(values []llvm.Value, slicetyp llvm.Type) llvm.Value {
	ptrtyp := slicetyp.StructElementTypes()[0]
	var globalptr llvm.Value
	if len(values) > 0 {
		array := llvm.ConstArray(ptrtyp.ElementType(), values)
		globalptr = llvm.AddGlobal(tm.module, array.Type(), "")
		globalptr.SetInitializer(array)
		globalptr = llvm.ConstBitCast(globalptr, ptrtyp)
	} else {
		globalptr = llvm.ConstNull(ptrtyp)
	}
	len_ := llvm.ConstInt(tm.inttype, uint64(len(values)), false)
	slice := llvm.ConstNull(slicetyp)
	slice = llvm.ConstInsertValue(slice, globalptr, []uint32{0})
	slice = llvm.ConstInsertValue(slice, len_, []uint32{1})
	slice = llvm.ConstInsertValue(slice, len_, []uint32{2})
	return slice
}

// convertI2V converts an interface to a value.
func (v *LLVMValue) convertI2V(typ types.Type) (result, success Value) {
	typptrType := llvm.PointerType(llvm.Int8Type(), 0)
	runtimeType := v.compiler.types.ToRuntime(typ)
	runtimeType = llvm.ConstBitCast(runtimeType, typptrType)
	vval := v.LLVMValue()

	builder := v.compiler.builder
	ifaceType := builder.CreateExtractValue(vval, 0, "")
	diff := builder.CreatePtrDiff(runtimeType, ifaceType, "")
	zero := llvm.ConstNull(diff.Type())
	predicate := builder.CreateICmp(llvm.IntEQ, diff, zero, "")

	// If result is zero, then we've got a match.
	end := llvm.InsertBasicBlock(builder.GetInsertBlock(), "end")
	end.MoveAfter(builder.GetInsertBlock())
	nonmatch := llvm.InsertBasicBlock(end, "nonmatch")
	match := llvm.InsertBasicBlock(nonmatch, "match")
	builder.CreateCondBr(predicate, match, nonmatch)

	builder.SetInsertPointAtEnd(match)
	matchResultValue := v.loadI2V(typ).LLVMValue()
	builder.CreateBr(end)

	builder.SetInsertPointAtEnd(nonmatch)
	nonmatchResultValue := llvm.ConstNull(matchResultValue.Type())
	builder.CreateBr(end)

	builder.SetInsertPointAtEnd(end)
	successValue := builder.CreatePHI(llvm.Int1Type(), "")
	resultValue := builder.CreatePHI(matchResultValue.Type(), "")

	successValues := []llvm.Value{llvm.ConstAllOnes(llvm.Int1Type()), llvm.ConstNull(llvm.Int1Type())}
	successBlocks := []llvm.BasicBlock{match, nonmatch}
	successValue.AddIncoming(successValues, successBlocks)
	success = v.compiler.NewLLVMValue(successValue, types.Bool)

	resultValues := []llvm.Value{matchResultValue, nonmatchResultValue}
	resultBlocks := []llvm.BasicBlock{match, nonmatch}
	resultValue.AddIncoming(resultValues, resultBlocks)
	result = v.compiler.NewLLVMValue(resultValue, typ)
	return result, success
}