func (c *compiler) VisitFuncProtoDecl(f *ast.FuncDecl) *LLVMValue {
	if f.Name.Obj != nil {
		if result, ok := f.Name.Obj.Data.(*LLVMValue); ok {
			return result
		}
	}

	var ftyp *types.Func
	fname := f.Name.String()
	if f.Recv == nil && fname == "init" {
		// Make "init" functions anonymous.
		fname = ""
		// "init" functions aren't recorded by the parser, so f.Name.Obj is
		// not set.
		ftyp = &types.Func{ /* no params or result */ }
	} else {
		ftyp = f.Name.Obj.Type.(*types.Func)
		if ftyp.Recv != nil {
			recv := ftyp.Recv.Type.(types.Type)
			fname = fmt.Sprintf("%s.%s", recv, fname)
		} else if c.module.Name != "main" || fname != "main" {
			pkgname := c.pkgmap[f.Name.Obj]
			fname = pkgname + "." + fname
		}
	}

	// gcimporter may produce multiple AST objects for the same function.
	fn := c.module.Module.NamedFunction(fname)
	if fn.IsNil() {
		llvmftyp := c.types.ToLLVM(ftyp).ElementType()
		fn = llvm.AddFunction(c.module.Module, fname, llvmftyp)
		if ftyp.Recv != nil {
			// Create an interface function if the receiver is
			// not a pointer type.
			recvtyp := ftyp.Recv.Type.(types.Type)
			if _, ptr := recvtyp.(*types.Pointer); !ptr {
				returntyp := llvmftyp.ReturnType()
				paramtypes := llvmftyp.ParamTypes()
				paramtypes[0] = llvm.PointerType(paramtypes[0], 0)
				ifntyp := llvm.FunctionType(returntyp, paramtypes, false)
				llvm.AddFunction(c.module.Module, "*"+fname, ifntyp)
			}
		}
	}
	result := c.NewLLVMValue(fn, ftyp)
	if f.Name.Obj != nil {
		f.Name.Obj.Data = result
		f.Name.Obj.Type = ftyp
	}
	return result
}

func (c *compiler) defineMemcpyFunction(fn llvm.Value) {
	entry := llvm.AddBasicBlock(fn, "entry")
	c.builder.SetInsertPointAtEnd(entry)
	dst, src, size := fn.Param(0), fn.Param(1), fn.Param(2)

	pint8 := llvm.PointerType(llvm.Int8Type(), 0)
	dst = c.builder.CreateIntToPtr(dst, pint8, "")
	src = c.builder.CreateIntToPtr(src, pint8, "")

	sizeType := size.Type()
	sizeBits := sizeType.IntTypeWidth()
	memcpyName := "llvm.memcpy.p0i8.p0i8.i" + strconv.Itoa(sizeBits)
	memcpy := c.module.NamedFunction(memcpyName)
	if memcpy.IsNil() {
		paramtypes := []llvm.Type{
			pint8, pint8, size.Type(), llvm.Int32Type(), llvm.Int1Type()}
		memcpyType := llvm.FunctionType(llvm.VoidType(), paramtypes, false)
		memcpy = llvm.AddFunction(c.module.Module, memcpyName, memcpyType)
	}

	args := []llvm.Value{
		dst, src, size,
		llvm.ConstInt(llvm.Int32Type(), 1, false), // single byte alignment
		llvm.ConstInt(llvm.Int1Type(), 0, false),  // not volatile
	}
	c.builder.CreateCall(memcpy, args, "")
	c.builder.CreateRetVoid()
}

func addExterns(m *llgo.Module) {
	CharPtr := llvm.PointerType(llvm.Int8Type(), 0)
	fn_type := llvm.FunctionType(
		llvm.Int32Type(), []llvm.Type{CharPtr}, false)
	fflush := llvm.AddFunction(m.Module, "fflush", fn_type)
	fflush.SetFunctionCallConv(llvm.CCallConv)
}

func (c *compiler) compareStrings(lhs, rhs *LLVMValue, op token.Token) *LLVMValue {
	strcmp := c.module.Module.NamedFunction("runtime.strcmp")
	if strcmp.IsNil() {
		string_type := c.types.ToLLVM(types.String)
		param_types := []llvm.Type{string_type, string_type}
		func_type := llvm.FunctionType(llvm.Int32Type(), param_types, false)
		strcmp = llvm.AddFunction(c.module.Module, "runtime.strcmp", func_type)
	}
	args := []llvm.Value{lhs.LLVMValue(), rhs.LLVMValue()}
	result := c.builder.CreateCall(strcmp, args, "")
	zero := llvm.ConstNull(llvm.Int32Type())
	var pred llvm.IntPredicate
	switch op {
	case token.EQL:
		pred = llvm.IntEQ
	case token.LSS:
		pred = llvm.IntSLT
	case token.GTR:
		pred = llvm.IntSGT
	case token.LEQ:
		pred = llvm.IntSLE
	case token.GEQ:
		pred = llvm.IntSGE
	case token.NEQ:
		panic("NEQ is handled in LLVMValue.BinaryOp")
	default:
		panic("unreachable")
	}
	result = c.builder.CreateICmp(pred, result, zero, "")
	return c.NewLLVMValue(result, types.Bool)
}

// mapInsert inserts a key into a map, returning a pointer to the memory
// location for the value.
func (c *compiler) mapInsert(m *LLVMValue, key Value) *LLVMValue {
	mapType := m.Type().(*types.Map)
	mapinsert := c.module.Module.NamedFunction("runtime.mapinsert")
	ptrType := c.target.IntPtrType()
	if mapinsert.IsNil() {
		// params: dynamic type, mapptr, keyptr
		paramTypes := []llvm.Type{ptrType, ptrType, ptrType}
		funcType := llvm.FunctionType(ptrType, paramTypes, false)
		mapinsert = llvm.AddFunction(c.module.Module, "runtime.mapinsert", funcType)
	}
	args := make([]llvm.Value, 3)
	args[0] = llvm.ConstPtrToInt(c.types.ToRuntime(m.Type()), ptrType)
	args[1] = c.builder.CreatePtrToInt(m.pointer.LLVMValue(), ptrType, "")

	if lv, islv := key.(*LLVMValue); islv && lv.pointer != nil {
		args[2] = c.builder.CreatePtrToInt(lv.pointer.LLVMValue(), ptrType, "")
	}
	if args[2].IsNil() {
		// Create global constant, so we can take its address.
		global := llvm.AddGlobal(c.module.Module, c.types.ToLLVM(key.Type()), "")
		global.SetGlobalConstant(true)
		global.SetInitializer(key.LLVMValue())
		args[2] = c.builder.CreatePtrToInt(global, ptrType, "")
	}

	eltPtrType := &types.Pointer{Base: mapType.Elt}
	result := c.builder.CreateCall(mapinsert, args, "")
	result = c.builder.CreateIntToPtr(result, c.types.ToLLVM(eltPtrType), "")
	value := c.NewLLVMValue(result, eltPtrType)
	return value.makePointee()
}

// interfacesEqual compares two interfaces for equality, returning
// a dynamic boolean value.
func (lhs *LLVMValue) compareI2I(rhs *LLVMValue) Value {
	c := lhs.compiler
	b := c.builder

	lhsValue := b.CreateExtractValue(lhs.LLVMValue(), 0, "")
	rhsValue := b.CreateExtractValue(rhs.LLVMValue(), 0, "")
	lhsType := b.CreateExtractValue(lhs.LLVMValue(), 1, "")
	rhsType := b.CreateExtractValue(rhs.LLVMValue(), 1, "")

	llvmUintptr := c.target.IntPtrType()
	runtimeCompareI2I := c.module.Module.NamedFunction("runtime.compareI2I")
	if runtimeCompareI2I.IsNil() {
		args := []llvm.Type{llvmUintptr, llvmUintptr, llvmUintptr, llvmUintptr}
		functype := llvm.FunctionType(llvm.Int1Type(), args, false)
		runtimeCompareI2I = llvm.AddFunction(
			c.module.Module, "runtime.compareI2I", functype)
	}

	args := []llvm.Value{
		c.builder.CreatePtrToInt(lhsType, llvmUintptr, ""),
		c.builder.CreatePtrToInt(rhsType, llvmUintptr, ""),
		c.builder.CreatePtrToInt(lhsValue, llvmUintptr, ""),
		c.builder.CreatePtrToInt(rhsValue, llvmUintptr, ""),
	}

	result := c.builder.CreateCall(runtimeCompareI2I, args, "")
	return c.NewLLVMValue(result, types.Bool)
}

// contextFunction creates a wrapper function that
// has the same signature as the specified function,
// but has an additional first parameter that accepts
// and ignores the function context value.
//
// contextFunction must be called with a global function
// pointer.
func contextFunction(c *compiler, f *LLVMValue) *LLVMValue {
	defer c.builder.SetInsertPointAtEnd(c.builder.GetInsertBlock())
	resultType := c.llvmtypes.ToLLVM(f.Type())
	fnptr := f.LLVMValue()
	contextType := resultType.StructElementTypes()[1]
	llfntyp := fnptr.Type().ElementType()
	llfntyp = llvm.FunctionType(
		llfntyp.ReturnType(),
		append([]llvm.Type{contextType}, llfntyp.ParamTypes()...),
		llfntyp.IsFunctionVarArg(),
	)
	wrapper := llvm.AddFunction(c.module.Module, fnptr.Name()+".ctx", llfntyp)
	wrapper.SetLinkage(llvm.PrivateLinkage)
	entry := llvm.AddBasicBlock(wrapper, "entry")
	c.builder.SetInsertPointAtEnd(entry)
	args := make([]llvm.Value, len(llfntyp.ParamTypes())-1)
	for i := range args {
		args[i] = wrapper.Param(i + 1)
	}
	result := c.builder.CreateCall(fnptr, args, "")
	switch nresults := f.Type().(*types.Signature).Results().Len(); nresults {
	case 0:
		c.builder.CreateRetVoid()
	case 1:
		c.builder.CreateRet(result)
	default:
		results := make([]llvm.Value, nresults)
		for i := range results {
			results[i] = c.builder.CreateExtractValue(result, i, "")
		}
		c.builder.CreateAggregateRet(results)
	}
	return c.NewValue(wrapper, f.Type())
}

func (c *compiler) VisitFuncProtoDecl(f *ast.FuncDecl) Value {
	var fn_type *types.Func
	fn_name := f.Name.String()

	exported := ast.IsExported(fn_name)
	if fn_name == "init" {
		// Make "init" functions anonymous.
		fn_name = ""
		// "init" functions aren't recorded by the parser, so f.Name.Obj is
		// not set.
		fn_type = &types.Func{ /* no params or result */ }
	} else {
		fn_type = f.Name.Obj.Type.(*types.Func)
		if c.module.Name == "main" && fn_name == "main" {
			exported = true
		} else {
			pkgname := c.pkgmap[f.Name.Obj]
			fn_name = pkgname + "." + fn_name
		}
	}

	llvm_fn_type := c.types.ToLLVM(fn_type).ElementType()
	fn := llvm.AddFunction(c.module.Module, fn_name, llvm_fn_type)
	if exported {
		fn.SetLinkage(llvm.ExternalLinkage)
	}

	result := c.NewLLVMValue(fn, fn_type)
	if f.Name.Obj != nil {
		f.Name.Obj.Data = result
		f.Name.Obj.Type = fn_type
	}
	return result
}

func (c *compiler) VisitFuncLit(lit *ast.FuncLit) Value {
	ftyp := c.types.expr[lit].(*types.Func)
	fn_value := llvm.AddFunction(c.module.Module, "", c.types.ToLLVM(ftyp).ElementType())
	fn_value.SetFunctionCallConv(llvm.FastCallConv)
	defer c.builder.SetInsertPointAtEnd(c.builder.GetInsertBlock())
	f := c.NewLLVMValue(fn_value, ftyp)
	c.buildFunction(f, ftyp.Params, lit.Body)
	return f
}

func getPrintf(module llvm.Module) llvm.Value {
	printf := module.NamedFunction("printf")
	if printf.IsNil() {
		charPtr := llvm.PointerType(llvm.Int8Type(), 0)
		ftyp := llvm.FunctionType(llvm.Int32Type(), []llvm.Type{charPtr}, true)
		printf = llvm.AddFunction(module, "printf", ftyp)
		printf.SetFunctionCallConv(llvm.CCallConv)
	}
	return printf
}

func getFflush(module llvm.Module) llvm.Value {
	fflush := module.NamedFunction("fflush")
	if fflush.IsNil() {
		voidPtr := llvm.PointerType(llvm.Int8Type(), 0)
		ftyp := llvm.FunctionType(llvm.Int32Type(), []llvm.Type{voidPtr}, false)
		fflush = llvm.AddFunction(module, "fflush", ftyp)
		fflush.SetFunctionCallConv(llvm.CCallConv)
	}
	return fflush
}

func (c *FunctionCache) NamedFunction(name string, signature string) llvm.Value {
	f, _ := c.functions[name+":"+signature]
	if !f.IsNil() {
		return f
	}

	if strings.HasPrefix(name, c.module.Name+".") {
		obj := c.pkg.Scope.Lookup(name[len(c.module.Name)+1:])
		value := c.Resolve(obj)
		f = value.LLVMValue()
	} else {
		fset := token.NewFileSet()
		code := `package runtime;import("unsafe");` + signature + `{panic()}`
		file, err := parser.ParseFile(fset, "", code, 0)
		if err != nil {
			panic(err)
		}

		// Parse the runtime package, since we may need to refer to
		// its types. TODO cache the package.
		buildpkg, err := build.Import("github.com/axw/llgo/pkg/runtime", "", 0)
		if err != nil {
			panic(err)
		}
		runtimefiles := make([]string, len(buildpkg.GoFiles))
		for i, f := range buildpkg.GoFiles {
			runtimefiles[i] = path.Join(buildpkg.Dir, f)
		}

		files, err := parseFiles(fset, runtimefiles)
		if err != nil {
			panic(err)
		}
		files["<src>"] = file
		pkg, err := ast.NewPackage(fset, files, types.GcImport, types.Universe)
		if err != nil {
			panic(err)
		}

		_, err = types.Check(fset, pkg)
		if err != nil {
			panic(err)
		}

		fdecl := file.Decls[len(file.Decls)-1].(*ast.FuncDecl)
		ftype := fdecl.Name.Obj.Type.(*types.Func)
		llvmfptrtype := c.types.ToLLVM(ftype)
		f = llvm.AddFunction(c.module.Module, name, llvmfptrtype.ElementType())
		if !strings.HasPrefix(name, "llvm.") {
			f.SetLinkage(llvm.AvailableExternallyLinkage)
		}
	}
	c.functions[name+":"+signature] = f
	return f
}

func (c *compiler) createMainFunction() error {
	// In a PNaCl program (plugin), there should not be a "main.main";
	// instead, we expect a "main.CreateModule" function.
	// See pkg/nacl/ppapi/ppapi.go for more details.
	mainMain := c.module.NamedFunction("main.main")
	/*
		if c.pnacl {
			// PNaCl's libppapi_stub.a implements "main", which simply
			// calls through to PpapiPluginMain. We define our own "main"
			// so that we can capture argc/argv.
			if !mainMain.IsNil() {
				return fmt.Errorf("Found main.main")
			}
			pluginMain := c.RuntimeFunction("PpapiPluginMain", "func() int32")

			// Synthesise a main which has no return value. We could cast
			// PpapiPluginMain, but this is potentially unsafe as its
			// calling convention is unspecified.
			ftyp := llvm.FunctionType(llvm.VoidType(), nil, false)
			mainMain = llvm.AddFunction(c.module.Module, "main.main", ftyp)
			entry := llvm.AddBasicBlock(mainMain, "entry")
			c.builder.SetInsertPointAtEnd(entry)
			c.builder.CreateCall(pluginMain, nil, "")
			c.builder.CreateRetVoid()
		} else */{
		mainMain = c.module.NamedFunction("main.main")
	}

	if mainMain.IsNil() {
		return fmt.Errorf("Could not find main.main")
	}

	// runtime.main is called by main, with argc, argv, argp,
	// and a pointer to main.main, which must be a niladic
	// function with no result.
	runtimeMain := c.runtime.main.LLVMValue()

	ptrptr := llvm.PointerType(llvm.PointerType(llvm.Int8Type(), 0), 0)
	ftyp := llvm.FunctionType(llvm.Int32Type(), []llvm.Type{llvm.Int32Type(), ptrptr, ptrptr}, true)
	main := llvm.AddFunction(c.module.Module, "main", ftyp)

	c.builder.SetCurrentDebugLocation(c.debug.MDNode(nil))
	entry := llvm.AddBasicBlock(main, "entry")
	c.builder.SetInsertPointAtEnd(entry)
	runtimeMainParamTypes := runtimeMain.Type().ElementType().ParamTypes()
	args := []llvm.Value{
		main.Param(0), // argc
		main.Param(1), // argv
		main.Param(2), // argp
		c.builder.CreateBitCast(mainMain, runtimeMainParamTypes[3], ""),
	}
	result := c.builder.CreateCall(runtimeMain, args, "")
	c.builder.CreateRet(result)
	return nil
}

func (c *compiler) makeFunc(ident *ast.Ident, ftyp *types.Signature) *LLVMValue {
	fname := ident.String()
	if ftyp.Recv() == nil && fname == "init" {
		// Make "init" functions anonymous.
		fname = ""
	} else {
		var pkgname string
		if recv := ftyp.Recv(); recv != nil {
			var recvname string
			switch recvtyp := recv.Type().(type) {
			case *types.Pointer:
				if named, ok := recvtyp.Elem().(*types.Named); ok {
					obj := named.Obj()
					recvname = "*" + obj.Name()
					pkgname = obj.Pkg().Path()
				}
			case *types.Named:
				named := recvtyp
				obj := named.Obj()
				recvname = obj.Name()
				pkgname = obj.Pkg().Path()
			}

			if recvname != "" {
				fname = fmt.Sprintf("%s.%s", recvname, fname)
			} else {
				// If the receiver is an unnamed struct, we're
				// synthesising a method for an unnamed struct
				// type. There's no meaningful name to give the
				// function, so leave it up to LLVM.
				fname = ""
			}
		} else {
			obj := c.typeinfo.Objects[ident]
			pkgname = obj.Pkg().Path()
		}
		if fname != "" {
			fname = pkgname + "." + fname
		}
	}

	// gcimporter may produce multiple AST objects for the same function.
	llvmftyp := c.types.ToLLVM(ftyp)
	var fn llvm.Value
	if fname != "" {
		fn = c.module.Module.NamedFunction(fname)
	}
	if fn.IsNil() {
		llvmfptrtyp := llvmftyp.StructElementTypes()[0].ElementType()
		fn = llvm.AddFunction(c.module.Module, fname, llvmfptrtyp)
	}
	fn = llvm.ConstInsertValue(llvm.ConstNull(llvmftyp), fn, []uint32{0})
	return c.NewValue(fn, ftyp)
}

func (c *compiler) concatenateStrings(lhs, rhs *LLVMValue) *LLVMValue {
	strcat := c.module.Module.NamedFunction("runtime.strcat")
	if strcat.IsNil() {
		string_type := c.types.ToLLVM(types.String)
		param_types := []llvm.Type{string_type, string_type}
		func_type := llvm.FunctionType(string_type, param_types, false)
		strcat = llvm.AddFunction(c.module.Module, "runtime.strcat", func_type)
	}
	args := []llvm.Value{lhs.LLVMValue(), rhs.LLVMValue()}
	result := c.builder.CreateCall(strcat, args, "")
	return c.NewLLVMValue(result, types.String)
}

func (c *FunctionCache) NamedFunction(name string, signature string) llvm.Value {
	f, _ := c.functions[name+":"+signature]
	if !f.IsNil() {
		return f
	}

	if strings.HasPrefix(name, c.module.Name+".") {
		obj := c.pkg.Scope.Lookup(name[len(c.module.Name)+1:])
		value := c.Resolve(obj)
		f = value.LLVMValue()
	} else {
		fset := token.NewFileSet()
		code := `package runtime;import("unsafe");` + signature + `{panic()}`
		file, err := parser.ParseFile(fset, "", code, 0)
		if err != nil {
			panic(err)
		}

		// Parse the runtime package, since we may need to refer to
		// its types. Can't be cached, because type-checking can't
		// be done twice on the AST.
		buildpkg, err := build.Import("github.com/axw/llgo/pkg/runtime", "", 0)
		if err != nil {
			panic(err)
		}

		// All types visible to the compiler are in "types.go".
		runtimefiles := []string{path.Join(buildpkg.Dir, "types.go")}

		files, err := parseFiles(fset, runtimefiles)
		if err != nil {
			panic(err)
		}
		files["<src>"] = file

		pkg, err := ast.NewPackage(fset, files, types.GcImport, types.Universe)
		if err != nil {
			panic(err)
		}

		_, err = types.Check("", c.compiler, fset, pkg)
		if err != nil {
			panic(err)
		}

		fdecl := file.Decls[len(file.Decls)-1].(*ast.FuncDecl)
		ftype := fdecl.Name.Obj.Type.(*types.Func)
		llvmfptrtype := c.types.ToLLVM(ftype)
		f = llvm.AddFunction(c.module.Module, name, llvmfptrtype.ElementType())
	}
	c.functions[name+":"+signature] = f
	return f
}

func getnewgoroutine(module llvm.Module) llvm.Value {
	fn := module.NamedFunction("llgo_newgoroutine")
	if fn.IsNil() {
		i8Ptr := llvm.PointerType(llvm.Int8Type(), 0)
		VoidFnPtr := llvm.PointerType(llvm.FunctionType(
			llvm.VoidType(), []llvm.Type{i8Ptr}, false), 0)
		i32 := llvm.Int32Type()
		fn_type := llvm.FunctionType(
			llvm.VoidType(), []llvm.Type{VoidFnPtr, i8Ptr, i32}, true)
		fn = llvm.AddFunction(module, "llgo_newgoroutine", fn_type)
		fn.SetFunctionCallConv(llvm.CCallConv)
	}
	return fn
}

func (c *FunctionCache) NamedFunction(name string, signature string) llvm.Value {
	f, _ := c.functions[name+":"+signature]
	if !f.IsNil() {
		return f
	}

	if strings.HasPrefix(name, c.module.Name+".") {
		obj := c.pkg.Scope().Lookup(name[len(c.module.Name)+1:])
		if obj == nil {
			panic("Missing function: " + name)
		}
		value := c.Resolve(c.objectdata[obj].Ident)
		f = llvm.ConstExtractValue(value.LLVMValue(), []uint32{0})
	} else {
		fset := token.NewFileSet()
		code := `package runtime;import("unsafe");` + signature + `{panic("")}`
		file, err := parser.ParseFile(fset, "", code, 0)
		if err != nil {
			panic(err)
		}

		// Parse the runtime package, since we may need to refer to
		// its types. Can't be cached, because type-checking can't
		// be done twice on the AST.
		buildpkg, err := build.Import("github.com/axw/llgo/pkg/runtime", "", 0)
		if err != nil {
			panic(err)
		}

		// All types visible to the compiler are in "types.go".
		runtimefiles := []string{path.Join(buildpkg.Dir, "types.go")}

		files, err := parseFiles(fset, runtimefiles)
		if err != nil {
			panic(err)
		}
		files = append(files, file)
		_, _, err = c.typecheck("runtime", fset, files)
		if err != nil {
			panic(err)
		}

		fdecl := file.Decls[len(file.Decls)-1].(*ast.FuncDecl)
		ftype := c.objects[fdecl.Name].Type().(*types.Signature)
		llvmfntyp := c.types.ToLLVM(ftype).StructElementTypes()[0].ElementType()
		f = llvm.AddFunction(c.module.Module, name, llvmfntyp)
	}
	c.functions[name+":"+signature] = f
	return f
}

func (c *compiler) VisitFuncProtoDecl(f *ast.FuncDecl) *LLVMValue {
	if f.Name.Obj != nil {
		if result, ok := f.Name.Obj.Data.(*LLVMValue); ok {
			return result
		}
	}

	var fn_type *types.Func
	fn_name := f.Name.String()
	if f.Recv == nil && fn_name == "init" {
		// Make "init" functions anonymous.
		fn_name = ""
		// "init" functions aren't recorded by the parser, so f.Name.Obj is
		// not set.
		fn_type = &types.Func{ /* no params or result */ }
	} else {
		fn_type = f.Name.Obj.Type.(*types.Func)
		if c.module.Name != "main" || fn_name != "main" {
			if fn_type.Recv != nil {
				recv := fn_type.Recv
				if recvtyp, ok := recv.Type.(*types.Pointer); ok {
					recv = recvtyp.Base.(*types.Name).Obj
				} else {
					recv = recv.Type.(*types.Name).Obj
				}
				pkgname := c.pkgmap[recv]
				fn_name = pkgname + "." + recv.Name + "." + fn_name
			} else {
				pkgname := c.pkgmap[f.Name.Obj]
				fn_name = pkgname + "." + fn_name
			}
		}
	}

	llvm_fn_type := c.types.ToLLVM(fn_type).ElementType()

	// gcimporter may produce multiple AST objects for the same function.
	fn := c.module.Module.NamedFunction(fn_name)
	if fn.IsNil() {
		fn = llvm.AddFunction(c.module.Module, fn_name, llvm_fn_type)
	}
	result := c.NewLLVMValue(fn, fn_type)
	if f.Name.Obj != nil {
		f.Name.Obj.Data = result
		f.Name.Obj.Type = fn_type
	}
	return result
}

func (c *FunctionCache) NamedFunction(name string, signature string) llvm.Value {
	f, _ := c.functions[name+":"+signature]
	if !f.IsNil() {
		return f
	}

	if strings.HasPrefix(name, c.module.Name+".") {
		obj := c.pkg.Scope().Lookup(name[len(c.module.Name)+1:])
		if obj == nil {
			panic("Missing function: " + name)
		}
		value := c.Resolve(c.objectdata[obj].Ident)
		f = llvm.ConstExtractValue(value.LLVMValue(), []uint32{0})
	} else {
		if c.runtimetypespkg == nil {
			// Parse the runtime package, since we may need to refer to
			// its types.
			buildpkg, err := build.Import("github.com/axw/llgo/pkg/runtime", "", 0)
			if err != nil {
				panic(err)
			}

			// All types visible to the compiler are in "types.go".
			runtimefiles := []string{path.Join(buildpkg.Dir, "types.go")}

			fset := token.NewFileSet()
			files, err := parseFiles(fset, runtimefiles)
			if err != nil {
				panic(err)
			}
			c.runtimetypespkg, err = c.typecheck("runtime", fset, files)
			if err != nil {
				panic(err)
			}
		}

		pkg := c.runtimetypespkg
		scope := pkg.Scope().Child(0)
		ftype, _, err := types.Eval(signature+"{panic()}", pkg, scope)
		if err != nil {
			panic(err)
		}
		llvmfntyp := c.types.ToLLVM(ftype).StructElementTypes()[0].ElementType()
		f = llvm.AddFunction(c.module.Module, name, llvmfntyp)
	}
	c.functions[name+":"+signature] = f
	return f
}