func (tm *llvmTypeMap) basicLLVMType(b *types.Basic) llvm.Type {
	switch b.Kind() {
	case types.Bool:
		return llvm.Int1Type()
	case types.Int8, types.Uint8:
		return llvm.Int8Type()
	case types.Int16, types.Uint16:
		return llvm.Int16Type()
	case types.Int32, types.Uint32:
		return llvm.Int32Type()
	case types.Uint, types.Int:
		return tm.inttype
	case types.Int64, types.Uint64:
		return llvm.Int64Type()
	case types.Float32:
		return llvm.FloatType()
	case types.Float64:
		return llvm.DoubleType()
	case types.UnsafePointer, types.Uintptr:
		return tm.target.IntPtrType()
	case types.Complex64:
		f32 := llvm.FloatType()
		elements := []llvm.Type{f32, f32}
		return llvm.StructType(elements, false)
	case types.Complex128:
		f64 := llvm.DoubleType()
		elements := []llvm.Type{f64, f64}
		return llvm.StructType(elements, false)
	case types.String:
		i8ptr := llvm.PointerType(llvm.Int8Type(), 0)
		elements := []llvm.Type{i8ptr, tm.inttype}
		return llvm.StructType(elements, false)
	}
	panic(fmt.Sprint("unhandled kind: ", b.Kind))
}

func (tm *TypeMap) funcLLVMType(f *types.Func) llvm.Type {
	param_types := make([]llvm.Type, 0)

	// Add receiver parameter.
	if f.Recv != nil {
		recv_type := f.Recv.Type.(types.Type)
		param_types = append(param_types, tm.ToLLVM(recv_type))
	}

	for _, param := range f.Params {
		param_type := param.Type.(types.Type)
		param_types = append(param_types, tm.ToLLVM(param_type))
	}

	var return_type llvm.Type
	switch len(f.Results) {
	case 0:
		return_type = llvm.VoidType()
	case 1:
		return_type = tm.ToLLVM(f.Results[0].Type.(types.Type))
	default:
		elements := make([]llvm.Type, len(f.Results))
		for i, result := range f.Results {
			elements[i] = tm.ToLLVM(result.Type.(types.Type))
		}
		return_type = llvm.StructType(elements, false)
	}

	fn_type := llvm.FunctionType(return_type, param_types, false)
	return llvm.PointerType(fn_type, 0)
}

func (tm *TypeMap) basicLLVMType(b *types.Basic) llvm.Type {
	switch b.Kind {
	case types.BoolKind:
		return llvm.Int1Type()
	case types.Int8Kind, types.Uint8Kind:
		return llvm.Int8Type()
	case types.Int16Kind, types.Uint16Kind:
		return llvm.Int16Type()
	case types.Int32Kind, types.Uint32Kind:
		return llvm.Int32Type()
	case types.Int64Kind, types.Uint64Kind:
		return llvm.Int64Type()
	case types.Float32Kind:
		return llvm.FloatType()
	case types.Float64Kind:
		return llvm.DoubleType()
	case types.UnsafePointerKind, types.UintptrKind,
		types.UintKind, types.IntKind:
		return tm.target.IntPtrType()
	//case Complex64: TODO
	//case Complex128:
	//case UntypedInt:
	//case UntypedFloat:
	//case UntypedComplex:
	case types.StringKind:
		i8ptr := llvm.PointerType(llvm.Int8Type(), 0)
		elements := []llvm.Type{i8ptr, llvm.Int32Type()}
		return llvm.StructType(elements, false)
	}
	panic(fmt.Sprint("unhandled kind: ", b.Kind))
}

func (tm *TypeMap) sliceLLVMType(s *types.Slice) llvm.Type {
	elements := []llvm.Type{
		llvm.PointerType(tm.ToLLVM(s.Elt), 0),
		llvm.Int32Type(),
		llvm.Int32Type(),
	}
	return llvm.StructType(elements, false)
}

func (tm *LLVMTypeMap) funcLLVMType(tstr string, f *types.Signature) llvm.Type {
	typ, ok := tm.types[tstr]
	if !ok {
		// If there's a receiver change the receiver to an
		// additional (first) parameter, and take the value of
		// the resulting signature instead.
		var param_types []llvm.Type
		if recv := f.Recv(); recv != nil {
			params := f.Params()
			paramvars := make([]*types.Var, int(params.Len()+1))
			paramvars[0] = recv
			for i := 0; i < int(params.Len()); i++ {
				paramvars[i+1] = params.At(i)
			}
			params = types.NewTuple(paramvars...)
			f := types.NewSignature(nil, params, f.Results(), f.IsVariadic())
			return tm.ToLLVM(f)
		}

		typ = llvm.GlobalContext().StructCreateNamed("")
		tm.types[tstr] = typ

		params := f.Params()
		nparams := int(params.Len())
		for i := 0; i < nparams; i++ {
			typ := params.At(i).Type()
			if f.IsVariadic() && i == nparams-1 {
				typ = types.NewSlice(typ)
			}
			llvmtyp := tm.ToLLVM(typ)
			param_types = append(param_types, llvmtyp)
		}

		var return_type llvm.Type
		results := f.Results()
		switch nresults := int(results.Len()); nresults {
		case 0:
			return_type = llvm.VoidType()
		case 1:
			return_type = tm.ToLLVM(results.At(0).Type())
		default:
			elements := make([]llvm.Type, nresults)
			for i := range elements {
				result := results.At(i)
				elements[i] = tm.ToLLVM(result.Type())
			}
			return_type = llvm.StructType(elements, false)
		}

		fntyp := llvm.FunctionType(return_type, param_types, false)
		fnptrtyp := llvm.PointerType(fntyp, 0)
		i8ptr := llvm.PointerType(llvm.Int8Type(), 0)
		elements := []llvm.Type{fnptrtyp, i8ptr} // func, closure
		typ.StructSetBody(elements, false)
	}
	return typ
}

func (tm *llvmTypeMap) funcLLVMType(f *types.Signature, name string) llvm.Type {
	// If there's a receiver change the receiver to an
	// additional (first) parameter, and take the value of
	// the resulting signature instead.
	if recv := f.Recv(); recv != nil {
		params := f.Params()
		paramvars := make([]*types.Var, int(params.Len()+1))
		paramvars[0] = recv
		for i := 0; i < int(params.Len()); i++ {
			paramvars[i+1] = params.At(i)
		}
		params = types.NewTuple(paramvars...)
		f := types.NewSignature(nil, nil, params, f.Results(), f.Variadic())
		return tm.toLLVM(f, name)
	}

	if typ, ok := tm.types.At(f).(llvm.Type); ok {
		return typ
	}
	typ := llvm.GlobalContext().StructCreateNamed(name)
	tm.types.Set(f, typ)

	params := f.Params()
	param_types := make([]llvm.Type, params.Len())
	for i := range param_types {
		llvmtyp := tm.ToLLVM(params.At(i).Type())
		param_types[i] = llvmtyp
	}

	var return_type llvm.Type
	results := f.Results()
	switch nresults := int(results.Len()); nresults {
	case 0:
		return_type = llvm.VoidType()
	case 1:
		return_type = tm.ToLLVM(results.At(0).Type())
	default:
		elements := make([]llvm.Type, nresults)
		for i := range elements {
			result := results.At(i)
			elements[i] = tm.ToLLVM(result.Type())
		}
		return_type = llvm.StructType(elements, false)
	}

	fntyp := llvm.FunctionType(return_type, param_types, false)
	fnptrtyp := llvm.PointerType(fntyp, 0)
	i8ptr := llvm.PointerType(llvm.Int8Type(), 0)
	elements := []llvm.Type{fnptrtyp, i8ptr} // func, closure
	typ.StructSetBody(elements, false)
	return typ
}

func (tm *TypeMap) mapLLVMType(m *types.Map) llvm.Type {
	// XXX This map type will change in the future, when I get around to it.
	// At the moment, it's representing a really dumb singly linked list.
	list_type := llvm.GlobalContext().StructCreateNamed("")
	list_ptr_type := llvm.PointerType(list_type, 0)
	size_type := llvm.Int32Type()
	element_types := []llvm.Type{size_type, list_type}
	typ := llvm.StructType(element_types, false)
	tm.types[m] = typ

	list_element_types := []llvm.Type{
		list_ptr_type, tm.ToLLVM(m.Key), tm.ToLLVM(m.Elt)}
	list_type.StructSetBody(list_element_types, false)
	return typ
}

func (tm *TypeMap) interfaceLLVMType(i *types.Interface) llvm.Type {
	valptr_type := llvm.PointerType(llvm.Int8Type(), 0)
	typptr_type := valptr_type // runtimeCommonType may not be defined yet
	elements := make([]llvm.Type, 2+len(i.Methods))
	elements[0] = valptr_type // value
	elements[1] = typptr_type // type
	for n, m := range i.Methods {
		// Add an opaque pointer parameter to the function for the
		// struct pointer.
		fntype := m.Type.(*types.Func)
		receiver_type := &types.Pointer{Base: types.Int8}
		fntype.Recv = ast.NewObj(ast.Var, "")
		fntype.Recv.Type = receiver_type
		elements[n+2] = tm.ToLLVM(fntype)
	}
	return llvm.StructType(elements, false)
}

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
}

// makeClosure creates a closure from a function pointer and
// a set of bindings. The bindings are addresses of captured
// variables.
func (c *compiler) makeClosure(fn *LLVMValue, bindings []*LLVMValue) *LLVMValue {
	types := make([]llvm.Type, len(bindings))
	for i, binding := range bindings {
		types[i] = c.types.ToLLVM(binding.Type())
	}
	block := c.createTypeMalloc(llvm.StructType(types, false))
	for i, binding := range bindings {
		addressPtr := c.builder.CreateStructGEP(block, i, "")
		c.builder.CreateStore(binding.LLVMValue(), addressPtr)
	}
	block = c.builder.CreateBitCast(block, llvm.PointerType(llvm.Int8Type(), 0), "")
	// fn is a raw function pointer; ToLLVM yields {*fn, *uint8}.
	closure := llvm.Undef(c.types.ToLLVM(fn.Type()))
	fnptr := c.builder.CreateBitCast(fn.LLVMValue(), closure.Type().StructElementTypes()[0], "")
	closure = c.builder.CreateInsertValue(closure, fnptr, 0, "")
	closure = c.builder.CreateInsertValue(closure, block, 1, "")
	return c.NewValue(closure, fn.Type())
}

func (u *unit) resolveFunction(f *ssa.Function) *LLVMValue {
	if v, ok := u.globals[f]; ok {
		return v
	}
	name := f.String()
	if f.Enclosing != nil {
		// Anonymous functions are not guaranteed to
		// have unique identifiers at the global scope.
		name = f.Enclosing.String() + ":" + name
	}
	// It's possible that the function already exists in the module;
	// for example, if it's a runtime intrinsic that the compiler
	// has already referenced.
	llvmFunction := u.module.Module.NamedFunction(name)
	if llvmFunction.IsNil() {
		llvmType := u.llvmtypes.ToLLVM(f.Signature)
		llvmType = llvmType.StructElementTypes()[0].ElementType()
		if len(f.FreeVars) > 0 {
			// Add an implicit first argument.
			returnType := llvmType.ReturnType()
			paramTypes := llvmType.ParamTypes()
			vararg := llvmType.IsFunctionVarArg()
			blockElementTypes := make([]llvm.Type, len(f.FreeVars))
			for i, fv := range f.FreeVars {
				blockElementTypes[i] = u.llvmtypes.ToLLVM(fv.Type())
			}
			blockType := llvm.StructType(blockElementTypes, false)
			blockPtrType := llvm.PointerType(blockType, 0)
			paramTypes = append([]llvm.Type{blockPtrType}, paramTypes...)
			llvmType = llvm.FunctionType(returnType, paramTypes, vararg)
		}
		llvmFunction = llvm.AddFunction(u.module.Module, name, llvmType)
		if f.Enclosing != nil {
			llvmFunction.SetLinkage(llvm.PrivateLinkage)
		}
		u.undefinedFuncs[f] = true
	}
	v := u.NewValue(llvmFunction, f.Signature)
	u.globals[f] = v
	return v
}

func (tm *TypeMap) makeRuntimeTypeGlobal(v llvm.Value) (global, ptr llvm.Value) {
	runtimeTypeValue := llvm.ConstNull(tm.runtimeType)
	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))

	// Set ptrToThis in v's commonType.
	if v.Type() == tm.runtimeCommonType {
		v = llvm.ConstInsertValue(v, ptr, []uint32{9})
	} else {
		commonType := llvm.ConstExtractValue(v, []uint32{0})
		commonType = llvm.ConstInsertValue(commonType, ptr, []uint32{9})
		v = llvm.ConstInsertValue(v, commonType, []uint32{0})
	}

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

	return
}

func (c *compiler) VisitSelectorExpr(expr *ast.SelectorExpr) Value {
	selection := c.typeinfo.Selections[expr]

	// Imported package funcs/vars.
	if selection.Kind() == types.PackageObj {
		return c.Resolve(expr.Sel)
	}

	// Method expression. Returns an unbound function pointer.
	if selection.Kind() == types.MethodExpr {
		ftyp := c.typeinfo.Types[expr].(*types.Signature)
		recvtyp := ftyp.Params().At(0).Type()
		var name *types.Named
		var isptr bool
		if ptrtyp, ok := recvtyp.(*types.Pointer); ok {
			isptr = true
			name = ptrtyp.Elem().(*types.Named)
		} else {
			name = recvtyp.(*types.Named)
		}
		obj := c.methods(name).lookup(expr.Sel.Name, isptr)
		method := c.Resolve(c.objectdata[obj].Ident).(*LLVMValue)
		return c.NewValue(method.value, ftyp)
	}

	// Interface: search for method by name.
	lhs := c.VisitExpr(expr.X)
	name := expr.Sel.Name
	if iface, ok := lhs.Type().Underlying().(*types.Interface); ok {
		i := selection.Index()[0]
		ftype := selection.Type()
		methodset := iface.MethodSet()
		if methodset.At(i).Obj() != selection.Obj() {
			// TODO cache mapping from unsorted to sorted index.
			for j := 0; j < methodset.Len(); j++ {
				if methodset.At(j).Obj() == selection.Obj() {
					i = j
					break
				}
			}
		}

		structValue := lhs.LLVMValue()
		receiver := c.builder.CreateExtractValue(structValue, 1, "")
		f := c.builder.CreateExtractValue(structValue, i+2, "")
		types := []llvm.Type{f.Type(), receiver.Type()}
		llvmStructType := llvm.StructType(types, false)
		structValue = llvm.Undef(llvmStructType)
		structValue = c.builder.CreateInsertValue(structValue, f, 0, "")
		structValue = c.builder.CreateInsertValue(structValue, receiver, 1, "")
		return c.NewValue(structValue, ftype)
	}

	// Method.
	if selection.Kind() == types.MethodVal {
		var isptr bool
		typ := lhs.Type()
		if ptr, ok := typ.(*types.Pointer); ok {
			typ = ptr.Elem()
			isptr = true
		} else {
			isptr = lhs.(*LLVMValue).pointer != nil
		}
		recv := lhs.(*LLVMValue)
		if isptr && typ == lhs.Type() {
			recv = recv.pointer
		}
		method := c.methods(typ).lookup(name, isptr)
		if f, ok := method.(*types.Func); ok {
			method = c.methodfunc(f)
		}
		methodValue := c.Resolve(c.objectdata[method].Ident).LLVMValue()
		methodValue = c.builder.CreateExtractValue(methodValue, 0, "")
		recvValue := recv.LLVMValue()
		types := []llvm.Type{methodValue.Type(), recvValue.Type()}
		structType := llvm.StructType(types, false)
		value := llvm.Undef(structType)
		value = c.builder.CreateInsertValue(value, methodValue, 0, "")
		value = c.builder.CreateInsertValue(value, recvValue, 1, "")
		v := c.NewValue(value, method.Type())
		v.method = method
		return v
	}

	// Get a pointer to the field.
	fieldValue := lhs.(*LLVMValue)
	if fieldValue.pointer == nil {
		// If we've got a temporary (i.e. no pointer),
		// then load the value onto the stack.
		v := fieldValue.value
		stackptr := c.builder.CreateAlloca(v.Type(), "")
		c.builder.CreateStore(v, stackptr)
		ptrtyp := types.NewPointer(fieldValue.Type())
		fieldValue = c.NewValue(stackptr, ptrtyp).makePointee()
	}
	for _, i := range selection.Index() {
		if _, ok := fieldValue.Type().(*types.Pointer); ok {
			fieldValue = fieldValue.makePointee()
		}
		ptr := fieldValue.pointer.LLVMValue()
//.........这里部分代码省略.........

// makeDeferBlock creates a basic block for handling
// defer statements, and code is emitted to allocate and
// initialise a deferred function anchor point.
//
// This must be called before generating any code for
// the function body (not including allocating space
// for parameters and results).
func (c *compiler) makeDeferBlock(f *function, body *ast.BlockStmt) {
	currblock := c.builder.GetInsertBlock()
	defer c.builder.SetInsertPointAtEnd(currblock)

	// Create space for a pointer on the stack, which
	// we'll store the first panic structure in.
	//
	// TODO consider having stack space for one (or few)
	// defer statements, to avoid heap allocation.
	//
	// TODO delay this until just before the first "invoke"
	// instruction is emitted.
	f.deferblock = llvm.AddBasicBlock(currblock.Parent(), "defer")
	if hasCallExpr(body) {
		f.unwindblock = llvm.AddBasicBlock(currblock.Parent(), "unwind")
		f.unwindblock.MoveAfter(currblock)
		f.deferblock.MoveAfter(f.unwindblock)
	} else {
		f.deferblock.MoveAfter(currblock)
	}

	// Create a landingpad/unwind target basic block.
	if !f.unwindblock.IsNil() {
		c.builder.SetInsertPointAtEnd(f.unwindblock)
		i8ptr := llvm.PointerType(llvm.Int8Type(), 0)
		restyp := llvm.StructType([]llvm.Type{i8ptr, llvm.Int32Type()}, false)
		pers := c.module.Module.NamedFunction("__gxx_personality_v0")
		if pers.IsNil() {
			persftyp := llvm.FunctionType(llvm.Int32Type(), nil, true)
			pers = llvm.AddFunction(c.module.Module, "__gxx_personality_v0", persftyp)
		}
		lp := c.builder.CreateLandingPad(restyp, pers, 1, "")
		lp.AddClause(llvm.ConstNull(i8ptr))

		// Catch the exception.
		begin_catch := c.NamedFunction("__cxa_begin_catch", "func f(*int8) *int8")
		exception := c.builder.CreateExtractValue(llvm.Value(lp), 0, "")
		c.builder.CreateCall(begin_catch, []llvm.Value{exception}, "")
		end_catch := c.NamedFunction("__cxa_end_catch", "func f()")
		c.builder.CreateCall(end_catch, nil, "")

		c.builder.CreateBr(f.deferblock)
	}

	// Create a real return instruction.
	c.builder.SetInsertPointAtEnd(f.deferblock)
	rundefers := c.NamedFunction("runtime.rundefers", "func f()")
	c.builder.CreateCall(rundefers, nil, "")

	if f.results.Len() == 0 {
		c.builder.CreateRetVoid()
	} else {
		values := make([]llvm.Value, 0, f.results.Len())
		f.results.ForEach(func(v *types.Var) {
			value := c.objectdata[v].Value.LLVMValue()
			values = append(values, value)
		})
		if len(values) == 1 {
			c.builder.CreateRet(values[0])
		} else {
			c.builder.CreateAggregateRet(values)
		}
	}
}

func (compiler *compiler) Compile(fset *token.FileSet,
	pkg *ast.Package, importpath string,
	exprTypes map[ast.Expr]types.Type) (m *Module, err error) {
	// FIXME create a compilation state, rather than storing in 'compiler'.
	compiler.fileset = fset
	compiler.pkg = pkg
	compiler.importpath = importpath
	compiler.initfuncs = nil
	compiler.varinitfuncs = nil

	// Create a Builder, for building LLVM instructions.
	compiler.builder = llvm.GlobalContext().NewBuilder()
	defer compiler.builder.Dispose()

	// Create a TargetMachine from the OS & Arch.
	triple := compiler.GetTargetTriple()
	var machine llvm.TargetMachine
	for target := llvm.FirstTarget(); target.C != nil && machine.C == nil; target = target.NextTarget() {
		if target.Name() == compiler.targetArch {
			machine = target.CreateTargetMachine(triple, "", "",
				llvm.CodeGenLevelDefault,
				llvm.RelocDefault,
				llvm.CodeModelDefault)
			defer machine.Dispose()
		}
	}

	if machine.C == nil {
		err = fmt.Errorf("Invalid target triple: %s", triple)
		return
	}

	// Create a Module, which contains the LLVM bitcode. Dispose it on panic,
	// otherwise we'll set a finalizer at the end. The caller may invoke
	// Dispose manually, which will render the finalizer a no-op.
	modulename := pkg.Name
	compiler.target = machine.TargetData()
	compiler.module = &Module{llvm.NewModule(modulename), modulename, false}
	compiler.module.SetTarget(triple)
	compiler.module.SetDataLayout(compiler.target.String())
	defer func() {
		if e := recover(); e != nil {
			compiler.module.Dispose()
			panic(e)
			//err = e.(error)
		}
	}()

	// Create a mapping from objects back to packages, so we can create the
	// appropriate symbol names.
	compiler.pkgmap = createPackageMap(pkg, importpath)

	// Create a struct responsible for mapping static types to LLVM types,
	// and to runtime/dynamic type values.
	var resolver Resolver = compiler
	llvmtypemap := NewLLVMTypeMap(compiler.module.Module, compiler.target)
	compiler.FunctionCache = NewFunctionCache(compiler)
	compiler.types = NewTypeMap(llvmtypemap, importpath, exprTypes, compiler.FunctionCache, compiler.pkgmap, resolver)

	// Compile each file in the package.
	for _, file := range pkg.Files {
		file.Scope.Outer = pkg.Scope
		compiler.filescope = file.Scope
		compiler.scope = file.Scope
		compiler.fixConstDecls(file)
		for _, decl := range file.Decls {
			compiler.VisitDecl(decl)
		}
	}

	// Define intrinsics for use by the runtime: malloc, free, memcpy, etc.
	// These could be defined in LLVM IR, and may be moved there later.
	if pkg.Name == "runtime" {
		compiler.defineRuntimeIntrinsics()
	}

	// Export runtime type information.
	if pkg.Name == "runtime" {
		compiler.exportBuiltinRuntimeTypes()
	}

	// Create global constructors.
	//
	// XXX When imports are handled, we'll need to defer creating
	//     llvm.global_ctors until we create an executable. This is
	//     due to (a) imports having to be initialised before the
	//     importer, and (b) LLVM having no specified order of
	//     initialisation for ctors with the same priority.
	var initfuncs [][]Value
	if compiler.varinitfuncs != nil {
		initfuncs = append(initfuncs, compiler.varinitfuncs)
	}
	if compiler.initfuncs != nil {
		initfuncs = append(initfuncs, compiler.initfuncs)
	}
	if initfuncs != nil {
		elttypes := []llvm.Type{llvm.Int32Type(), llvm.PointerType(llvm.FunctionType(llvm.VoidType(), nil, false), 0)}
		ctortype := llvm.StructType(elttypes, false)
		var ctors []llvm.Value
		var priority uint64
//.........这里部分代码省略.........

func (compiler *compiler) Compile(fset *token.FileSet,
	pkg *ast.Package, importpath string,
	exprTypes map[ast.Expr]types.Type) (m *Module, err error) {

	// FIXME I'd prefer if we didn't modify global state. Perhaps
	// we should always take a copy of types.Universe?
	defer func() {
		types.Universe.Lookup("true").Data = types.Const{true}
		types.Universe.Lookup("false").Data = types.Const{false}
	}()

	// FIXME create a compilation state, rather than storing in 'compiler'.
	compiler.fileset = fset
	compiler.pkg = pkg
	compiler.importpath = importpath
	compiler.initfuncs = nil
	compiler.varinitfuncs = nil

	// Create a Builder, for building LLVM instructions.
	compiler.builder = llvm.GlobalContext().NewBuilder()
	defer compiler.builder.Dispose()

	// Create a Module, which contains the LLVM bitcode. Dispose it on panic,
	// otherwise we'll set a finalizer at the end. The caller may invoke
	// Dispose manually, which will render the finalizer a no-op.
	modulename := pkg.Name
	compiler.module = &Module{llvm.NewModule(modulename), modulename, false}
	compiler.module.SetTarget(compiler.TargetTriple)
	compiler.module.SetDataLayout(compiler.target.String())
	defer func() {
		if e := recover(); e != nil {
			compiler.module.Dispose()
			panic(e)
			//err = e.(error)
		}
	}()

	// Create a mapping from objects back to packages, so we can create the
	// appropriate symbol names.
	compiler.pkgmap = createPackageMap(pkg, importpath)

	// Create a struct responsible for mapping static types to LLVM types,
	// and to runtime/dynamic type values.
	var resolver Resolver = compiler
	compiler.FunctionCache = NewFunctionCache(compiler)
	compiler.types = NewTypeMap(compiler.llvmtypes, compiler.module.Module, importpath, exprTypes, compiler.FunctionCache, resolver)

	// Compile each file in the package.
	for _, file := range pkg.Files {
		file.Scope.Outer = pkg.Scope
		compiler.filescope = file.Scope
		compiler.scope = file.Scope
		compiler.fixConstDecls(file)
		for _, decl := range file.Decls {
			compiler.VisitDecl(decl)
		}
	}

	// Define intrinsics for use by the runtime: malloc, free, memcpy, etc.
	// These could be defined in LLVM IR, and may be moved there later.
	if pkg.Name == "runtime" {
		compiler.defineRuntimeIntrinsics()
	}

	// Export runtime type information.
	if pkg.Name == "runtime" {
		compiler.exportBuiltinRuntimeTypes()
	}

	// Create global constructors. The initfuncs/varinitfuncs
	// slices are in the order of visitation, and that is how
	// their priorities are assigned.
	//
	// The llgo linker (llgo-link) is responsible for reordering
	// global constructors according to package dependency order.
	var initfuncs [][]Value
	if compiler.varinitfuncs != nil {
		initfuncs = append(initfuncs, compiler.varinitfuncs)
	}
	if compiler.initfuncs != nil {
		initfuncs = append(initfuncs, compiler.initfuncs)
	}
	if initfuncs != nil {
		elttypes := []llvm.Type{llvm.Int32Type(), llvm.PointerType(llvm.FunctionType(llvm.VoidType(), nil, false), 0)}
		ctortype := llvm.StructType(elttypes, false)
		var ctors []llvm.Value
		var priority uint64 = 1
		for _, initfuncs := range initfuncs {
			for _, fn := range initfuncs {
				priorityval := llvm.ConstInt(llvm.Int32Type(), uint64(priority), false)
				struct_values := []llvm.Value{priorityval, fn.LLVMValue()}
				ctors = append(ctors, llvm.ConstStruct(struct_values, false))
				priority++
			}
		}
		global_ctors_init := llvm.ConstArray(ctortype, ctors)
		global_ctors_var := llvm.AddGlobal(compiler.module.Module, global_ctors_init.Type(), "llvm.global_ctors")
		global_ctors_var.SetInitializer(global_ctors_init)
		global_ctors_var.SetLinkage(llvm.AppendingLinkage)
	}
//.........这里部分代码省略.........

func (c *compiler) VisitFuncLit(lit *ast.FuncLit) Value {
	ftyp := c.types.expr[lit].Type.(*types.Signature)

	// Walk the function literal, promoting stack vars not defined
	// in the function literal, and storing the ident's for non-const
	// values not declared in the function literal.
	//
	// (First, set a dummy "stack" value for the params and results.)
	var dummyfunc LLVMValue
	dummyfunc.stack = &dummyfunc
	paramVars := ftyp.Params()
	resultVars := ftyp.Results()
	c.functions.push(&function{
		LLVMValue: &dummyfunc,
		results:   resultVars,
	})
	v := &identVisitor{compiler: c}
	ast.Walk(v, lit.Body)
	c.functions.pop()

	// Create closure by adding a context parameter to the function,
	// and bind it with the values of the stack vars found in the
	// step above.
	origfnpairtyp := c.types.ToLLVM(ftyp)
	fnpairtyp := origfnpairtyp
	fntyp := origfnpairtyp.StructElementTypes()[0].ElementType()
	if v.captures != nil {
		// Add the additional context param.
		ctxfields := make([]*types.Field, len(v.captures))
		for i, capturevar := range v.captures {
			ctxfields[i] = &types.Field{
				Type: types.NewPointer(capturevar.Type()),
			}
		}
		ctxtyp := types.NewPointer(types.NewStruct(ctxfields, nil))
		llvmctxtyp := c.types.ToLLVM(ctxtyp)
		rettyp := fntyp.ReturnType()
		paramtyps := append([]llvm.Type{llvmctxtyp}, fntyp.ParamTypes()...)
		vararg := fntyp.IsFunctionVarArg()
		fntyp = llvm.FunctionType(rettyp, paramtyps, vararg)
		opaqueptrtyp := origfnpairtyp.StructElementTypes()[1]
		elttyps := []llvm.Type{llvm.PointerType(fntyp, 0), opaqueptrtyp}
		fnpairtyp = llvm.StructType(elttyps, false)
	}

	fnptr := llvm.AddFunction(c.module.Module, "", fntyp)
	fnvalue := llvm.ConstNull(fnpairtyp)
	fnvalue = llvm.ConstInsertValue(fnvalue, fnptr, []uint32{0})
	currBlock := c.builder.GetInsertBlock()

	f := c.NewValue(fnvalue, ftyp)
	captureVars := types.NewTuple(v.captures...)
	c.buildFunction(f, captureVars, paramVars, resultVars, lit.Body, ftyp.IsVariadic())

	// Closure? Bind values to a context block.
	if v.captures != nil {
		// Store the free variables in the heap allocated block.
		block := c.createTypeMalloc(fntyp.ParamTypes()[0].ElementType())
		for i, contextvar := range v.captures {
			value := c.objectdata[contextvar].Value
			blockPtr := c.builder.CreateStructGEP(block, i, "")
			c.builder.CreateStore(value.pointer.LLVMValue(), blockPtr)
		}

		// Cast the function pointer type back to the original
		// type, without the context parameter.
		fnptr = llvm.ConstBitCast(fnptr, origfnpairtyp.StructElementTypes()[0])
		fnvalue = llvm.Undef(origfnpairtyp)
		fnvalue = llvm.ConstInsertValue(fnvalue, fnptr, []uint32{0})

		// Set the context value.
		i8ptr := llvm.PointerType(llvm.Int8Type(), 0)
		block = c.builder.CreateBitCast(block, i8ptr, "")
		fnvalue = c.builder.CreateInsertValue(fnvalue, block, 1, "")
		f.value = fnvalue
	} else {
		c.builder.SetInsertPointAtEnd(currBlock)
	}

	return f
}

// indirectFunction creates an indirect function from a
// given function and arguments, suitable for use with
// "defer" and "go".
func (c *compiler) indirectFunction(fn *LLVMValue, args []*LLVMValue) *LLVMValue {
	nilarytyp := types.NewSignature(nil, nil, nil, nil, false)
	if len(args) == 0 {
		val := fn.LLVMValue()
		ptr := c.builder.CreateExtractValue(val, 0, "")
		ctx := c.builder.CreateExtractValue(val, 1, "")
		fnval := llvm.Undef(c.types.ToLLVM(nilarytyp))
		ptr = c.builder.CreateBitCast(ptr, fnval.Type().StructElementTypes()[0], "")
		ctx = c.builder.CreateBitCast(ctx, fnval.Type().StructElementTypes()[1], "")
		fnval = c.builder.CreateInsertValue(fnval, ptr, 0, "")
		fnval = c.builder.CreateInsertValue(fnval, ctx, 1, "")
		return c.NewValue(fnval, nilarytyp)
	}

	// Check if function pointer or context pointer is global/null.
	fnval := fn.LLVMValue()
	fnptr := fnval
	var nctx int
	var fnctx llvm.Value
	var fnctxindex uint64
	var globalfn bool
	if fnptr.Type().TypeKind() == llvm.StructTypeKind {
		fnptr = c.builder.CreateExtractValue(fnval, 0, "")
		fnctx = c.builder.CreateExtractValue(fnval, 1, "")
		globalfn = !fnptr.IsAFunction().IsNil()
		if !globalfn {
			nctx++
		}
		if !fnctx.IsNull() {
			fnctxindex = uint64(nctx)
			nctx++
		}
	} else {
		// We've got a raw global function pointer. Convert to <ptr,ctx>.
		fnval = llvm.ConstNull(c.types.ToLLVM(fn.Type()))
		fnval = llvm.ConstInsertValue(fnval, fnptr, []uint32{0})
		fn = c.NewValue(fnval, fn.Type())
		fnctx = llvm.ConstExtractValue(fnval, []uint32{1})
		globalfn = true
	}

	i8ptr := llvm.PointerType(llvm.Int8Type(), 0)
	llvmargs := make([]llvm.Value, len(args)+nctx)
	llvmargtypes := make([]llvm.Type, len(args)+nctx)
	for i, arg := range args {
		llvmargs[i+nctx] = arg.LLVMValue()
		llvmargtypes[i+nctx] = llvmargs[i+nctx].Type()
	}
	if !globalfn {
		llvmargtypes[0] = fnptr.Type()
		llvmargs[0] = fnptr
	}
	if !fnctx.IsNull() {
		llvmargtypes[fnctxindex] = fnctx.Type()
		llvmargs[fnctxindex] = fnctx
	}

	// TODO(axw) investigate an option for go statements
	// to allocate argument structure on the stack in the
	// initiator, and block until the spawned goroutine
	// has loaded the arguments from it.
	structtyp := llvm.StructType(llvmargtypes, false)
	argstruct := c.createTypeMalloc(structtyp)
	for i, llvmarg := range llvmargs {
		argptr := c.builder.CreateGEP(argstruct, []llvm.Value{
			llvm.ConstInt(llvm.Int32Type(), 0, false),
			llvm.ConstInt(llvm.Int32Type(), uint64(i), false)}, "")
		c.builder.CreateStore(llvmarg, argptr)
	}

	// Create a function that will take a pointer to a structure of the type
	// defined above, or no parameters if there are none to pass.
	fntype := llvm.FunctionType(llvm.VoidType(), []llvm.Type{argstruct.Type()}, false)
	indirectfn := llvm.AddFunction(c.module.Module, "", fntype)
	i8argstruct := c.builder.CreateBitCast(argstruct, i8ptr, "")
	currblock := c.builder.GetInsertBlock()
	c.builder.SetInsertPointAtEnd(llvm.AddBasicBlock(indirectfn, "entry"))
	argstruct = indirectfn.Param(0)
	newargs := make([]*LLVMValue, len(args))
	for i := range llvmargs[nctx:] {
		argptr := c.builder.CreateGEP(argstruct, []llvm.Value{
			llvm.ConstInt(llvm.Int32Type(), 0, false),
			llvm.ConstInt(llvm.Int32Type(), uint64(i+nctx), false)}, "")
		newargs[i] = c.NewValue(c.builder.CreateLoad(argptr, ""), args[i].Type())
	}

	// Unless we've got a global function, extract the
	// function pointer from the context.
	if !globalfn {
		fnval = llvm.Undef(fnval.Type())
		fnptrptr := c.builder.CreateGEP(argstruct, []llvm.Value{
			llvm.ConstInt(llvm.Int32Type(), 0, false),
			llvm.ConstInt(llvm.Int32Type(), 0, false)}, "")
		fnptr = c.builder.CreateLoad(fnptrptr, "")
		fnval = c.builder.CreateInsertValue(fnval, fnptr, 0, "")
	}
	if !fnctx.IsNull() {
//.........这里部分代码省略.........

// indirectFunction creates an indirect function from a
// given function, suitable for use with "defer" and "go".
func (c *compiler) indirectFunction(fn *LLVMValue, args []Value, dotdotdot bool) *LLVMValue {
	nilarytyp := &types.Signature{}
	if len(args) == 0 {
		val := fn.LLVMValue()
		ptr := c.builder.CreateExtractValue(val, 0, "")
		ctx := c.builder.CreateExtractValue(val, 1, "")
		fnval := llvm.Undef(c.types.ToLLVM(nilarytyp))
		ptr = c.builder.CreateBitCast(ptr, fnval.Type().StructElementTypes()[0], "")
		ctx = c.builder.CreateBitCast(ctx, fnval.Type().StructElementTypes()[1], "")
		fnval = c.builder.CreateInsertValue(fnval, ptr, 0, "")
		fnval = c.builder.CreateInsertValue(fnval, ctx, 1, "")
		fn = c.NewValue(fnval, nilarytyp)
		return fn
	}

	// TODO check if function pointer is global. I suppose
	// the same can be done with the context ptr...
	fnval := fn.LLVMValue()
	fnptr := c.builder.CreateExtractValue(fnval, 0, "")
	ctx := c.builder.CreateExtractValue(fnval, 1, "")
	nctx := 1 // fnptr
	if !ctx.IsNull() {
		nctx++ // fnctx
	}

	i8ptr := llvm.PointerType(llvm.Int8Type(), 0)
	llvmargs := make([]llvm.Value, len(args)+nctx)
	llvmargtypes := make([]llvm.Type, len(args)+nctx)
	for i, arg := range args {
		llvmargs[i+nctx] = arg.LLVMValue()
		llvmargtypes[i+nctx] = llvmargs[i+nctx].Type()
	}
	llvmargtypes[0] = fnptr.Type()
	llvmargs[0] = fnptr
	if nctx > 1 {
		llvmargtypes[1] = ctx.Type()
		llvmargs[1] = ctx
	}

	structtyp := llvm.StructType(llvmargtypes, false)
	argstruct := c.createTypeMalloc(structtyp)
	for i, llvmarg := range llvmargs {
		argptr := c.builder.CreateGEP(argstruct, []llvm.Value{
			llvm.ConstInt(llvm.Int32Type(), 0, false),
			llvm.ConstInt(llvm.Int32Type(), uint64(i), false)}, "")
		c.builder.CreateStore(llvmarg, argptr)
	}

	// Create a function that will take a pointer to a structure of the type
	// defined above, or no parameters if there are none to pass.
	fntype := llvm.FunctionType(llvm.VoidType(), []llvm.Type{argstruct.Type()}, false)
	indirectfn := llvm.AddFunction(c.module.Module, "", fntype)
	i8argstruct := c.builder.CreateBitCast(argstruct, i8ptr, "")
	currblock := c.builder.GetInsertBlock()
	c.builder.SetInsertPointAtEnd(llvm.AddBasicBlock(indirectfn, "entry"))
	argstruct = indirectfn.Param(0)
	for i := range llvmargs[nctx:] {
		argptr := c.builder.CreateGEP(argstruct, []llvm.Value{
			llvm.ConstInt(llvm.Int32Type(), 0, false),
			llvm.ConstInt(llvm.Int32Type(), uint64(i+nctx), false)}, "")
		ptrtyp := types.NewPointer(args[i].Type())
		args[i] = c.NewValue(argptr, ptrtyp).makePointee()
	}

	// Extract the function pointer.
	// TODO if function is a global, elide.
	fnval = llvm.Undef(fnval.Type())
	fnptrptr := c.builder.CreateGEP(argstruct, []llvm.Value{
		llvm.ConstInt(llvm.Int32Type(), 0, false),
		llvm.ConstInt(llvm.Int32Type(), 0, false)}, "")
	fnptr = c.builder.CreateLoad(fnptrptr, "")
	fnval = c.builder.CreateInsertValue(fnval, fnptr, 0, "")
	if nctx > 1 {
		ctxptr := c.builder.CreateGEP(argstruct, []llvm.Value{
			llvm.ConstInt(llvm.Int32Type(), 0, false),
			llvm.ConstInt(llvm.Int32Type(), 1, false)}, "")
		ctx = c.builder.CreateLoad(ctxptr, "")
		fnval = c.builder.CreateInsertValue(fnval, ctx, 1, "")
		fn = c.NewValue(fnval, fn.Type())
	}
	c.createCall(fn, args, dotdotdot, false)

	// Indirect function calls' return values are always ignored.
	c.builder.CreateRetVoid()
	c.builder.SetInsertPointAtEnd(currblock)

	fnval = llvm.Undef(c.types.ToLLVM(nilarytyp))
	indirectfn = c.builder.CreateBitCast(indirectfn, fnval.Type().StructElementTypes()[0], "")
	fnval = c.builder.CreateInsertValue(fnval, indirectfn, 0, "")
	fnval = c.builder.CreateInsertValue(fnval, i8argstruct, 1, "")
	fn = c.NewValue(fnval, nilarytyp)
	return fn
}