scope.go - platform/build/blueprint - Gitiles

 // Copyright 2014 Google Inc. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.

 package blueprint

 import (
 	"fmt"
 	"strings"
 	"unicode"
 	"unicode/utf8"
 )

 // A Variable represents a global Ninja variable definition that will be written
 // to the output .ninja file.  A variable may contain references to other global
 // Ninja variables, but circular variable references are not allowed.
 type Variable interface {
 	packageContext() *PackageContext
 	name() string                                        // "foo"
 	fullName(pkgNames map[*PackageContext]string) string // "pkg.foo" or "path.to.pkg.foo"
 	value(config interface{}) (*ninjaString, error)
 	String() string
 }

 // A Pool represents a Ninja pool that will be written to the output .ninja
 // file.
 type Pool interface {
 	packageContext() *PackageContext
 	name() string                                        // "foo"
 	fullName(pkgNames map[*PackageContext]string) string // "pkg.foo" or "path.to.pkg.foo"
 	def(config interface{}) (*poolDef, error)
 	String() string
 }

 // A Rule represents a Ninja build rule that will be written to the output
 // .ninja file.
 type Rule interface {
 	packageContext() *PackageContext
 	name() string                                        // "foo"
 	fullName(pkgNames map[*PackageContext]string) string // "pkg.foo" or "path.to.pkg.foo"
 	def(config interface{}) (*ruleDef, error)
 	scope() *basicScope
 	isArg(argName string) bool
 	String() string
 }

 type basicScope struct {
 	parent    *basicScope
 	variables map[string]Variable
 	pools     map[string]Pool
 	rules     map[string]Rule
 	imports   map[string]*basicScope
 }

 func newScope(parent *basicScope) *basicScope {
 	return &basicScope{
 		parent:    parent,
 		variables: make(map[string]Variable),
 		pools:     make(map[string]Pool),
 		rules:     make(map[string]Rule),
 		imports:   make(map[string]*basicScope),
 	}
 }

 func makeRuleScope(parent *basicScope, argNames map[string]bool) *basicScope {
 	scope := newScope(parent)
 	for argName := range argNames {
 		_, err := scope.LookupVariable(argName)
 		if err != nil {
 			arg := &argVariable{argName}
 			err = scope.AddVariable(arg)
 			if err != nil {
 				// This should not happen.  We should have already checked that
 				// the name is valid and that the scope doesn't have a variable
 				// with this name.
 				panic(err)
 			}
 		}
 	}

 	// We treat built-in variables like arguments for the purpose of this scope.
 	for _, builtin := range builtinRuleArgs {
 		arg := &argVariable{builtin}
 		err := scope.AddVariable(arg)
 		if err != nil {
 			panic(err)
 		}
 	}

 	return scope
 }

 func (s *basicScope) LookupVariable(name string) (Variable, error) {
 	dotIndex := strings.IndexRune(name, '.')
 	if dotIndex >= 0 {
 		// The variable name looks like "pkg.var"
 		if dotIndex+1 == len(name) {
 			return nil, fmt.Errorf("variable name %q ends with a '.'", name)
 		}
 		if strings.ContainsRune(name[dotIndex+1:], '.') {
 			return nil, fmt.Errorf("variable name %q contains multiple '.' "+
 				"characters", name)
 		}

 		pkgName := name[:dotIndex]
 		varName := name[dotIndex+1:]

 		first, _ := utf8.DecodeRuneInString(varName)
 		if !unicode.IsUpper(first) {
 			return nil, fmt.Errorf("cannot refer to unexported name %q", name)
 		}

 		importedScope, err := s.lookupImportedScope(pkgName)
 		if err != nil {
 			return nil, err
 		}

 		v, ok := importedScope.variables[varName]
 		if !ok {
 			return nil, fmt.Errorf("package %q does not contain variable %q",
 				pkgName, varName)
 		}

 		return v, nil
 	} else {
 		// The variable name has no package part; just "var"
 		for ; s != nil; s = s.parent {
 			v, ok := s.variables[name]
 			if ok {
 				return v, nil
 			}
 		}
 		return nil, fmt.Errorf("undefined variable %q", name)
 	}
 }

 func (s *basicScope) IsRuleVisible(rule Rule) bool {
 	_, isBuiltin := rule.(*builtinRule)
 	if isBuiltin {
 		return true
 	}

 	name := rule.name()

 	for s != nil {
 		if s.rules[name] == rule {
 			return true
 		}

 		for _, import_ := range s.imports {
 			if import_.rules[name] == rule {
 				return true
 			}
 		}

 		s = s.parent
 	}

 	return false
 }

 func (s *basicScope) IsPoolVisible(pool Pool) bool {
 	name := pool.name()

 	for s != nil {
 		if s.pools[name] == pool {
 			return true
 		}

 		for _, import_ := range s.imports {
 			if import_.pools[name] == pool {
 				return true
 			}
 		}

 		s = s.parent
 	}

 	return false
 }

 func (s *basicScope) lookupImportedScope(pkgName string) (*basicScope, error) {
 	for ; s != nil; s = s.parent {
 		importedScope, ok := s.imports[pkgName]
 		if ok {
 			return importedScope, nil
 		}
 	}
 	return nil, fmt.Errorf("unknown imported package %q (missing call to "+
 		"blueprint.Import()?)", pkgName)
 }

 func (s *basicScope) AddImport(name string, importedScope *basicScope) error {
 	_, present := s.imports[name]
 	if present {
 		return fmt.Errorf("import %q is already defined in this scope", name)
 	}
 	s.imports[name] = importedScope
 	return nil
 }

 func (s *basicScope) AddVariable(v Variable) error {
 	name := v.name()
 	_, present := s.variables[name]
 	if present {
 		return fmt.Errorf("variable %q is already defined in this scope", name)
 	}
 	s.variables[name] = v
 	return nil
 }

 func (s *basicScope) AddPool(p Pool) error {
 	name := p.name()
 	_, present := s.pools[name]
 	if present {
 		return fmt.Errorf("pool %q is already defined in this scope", name)
 	}
 	s.pools[name] = p
 	return nil
 }

 func (s *basicScope) AddRule(r Rule) error {
 	name := r.name()
 	_, present := s.rules[name]
 	if present {
 		return fmt.Errorf("rule %q is already defined in this scope", name)
 	}
 	s.rules[name] = r
 	return nil
 }

 type localScope struct {
 	namePrefix string
 	scope      *basicScope
 }

 func newLocalScope(parent *basicScope, namePrefix string) *localScope {
 	return &localScope{
 		namePrefix: namePrefix,
 		scope:      newScope(parent),
 	}
 }

 // ReparentTo sets the localScope's parent scope to the scope of the given
 // package context.  This allows a ModuleContext and SingletonContext to call
 // a function defined in a different Go package and have that function retain
 // access to all of the package-scoped variables of its own package.
 func (s *localScope) ReparentTo(pctx *PackageContext) {
 	s.scope.parent = pctx.scope
 }

 func (s *localScope) LookupVariable(name string) (Variable, error) {
 	return s.scope.LookupVariable(name)
 }

 func (s *localScope) IsRuleVisible(rule Rule) bool {
 	return s.scope.IsRuleVisible(rule)
 }

 func (s *localScope) IsPoolVisible(pool Pool) bool {
 	return s.scope.IsPoolVisible(pool)
 }

 func (s *localScope) AddLocalVariable(name, value string) (*localVariable,
 	error) {

 	err := validateNinjaName(name)
 	if err != nil {
 		return nil, err
 	}

 	if strings.ContainsRune(name, '.') {
 		return nil, fmt.Errorf("local variable name %q contains '.'", name)
 	}

 	ninjaValue, err := parseNinjaString(s.scope, value)
 	if err != nil {
 		return nil, err
 	}

 	v := &localVariable{
 		namePrefix: s.namePrefix,
 		name_:      name,
 		value_:     ninjaValue,
 	}

 	err = s.scope.AddVariable(v)
 	if err != nil {
 		return nil, err
 	}

 	return v, nil
 }

 func (s *localScope) AddLocalRule(name string, params *RuleParams,
 	argNames ...string) (*localRule, error) {

 	err := validateNinjaName(name)
 	if err != nil {
 		return nil, err
 	}

 	err = validateArgNames(argNames)
 	if err != nil {
 		return nil, fmt.Errorf("invalid argument name: %s", err)
 	}

 	argNamesSet := make(map[string]bool)
 	for _, argName := range argNames {
 		argNamesSet[argName] = true
 	}

 	ruleScope := makeRuleScope(s.scope, argNamesSet)

 	def, err := parseRuleParams(ruleScope, params)
 	if err != nil {
 		return nil, err
 	}

 	r := &localRule{
 		namePrefix: s.namePrefix,
 		name_:      name,
 		def_:       def,
 		argNames:   argNamesSet,
 		scope_:     ruleScope,
 	}

 	err = s.scope.AddRule(r)
 	if err != nil {
 		return nil, err
 	}

 	return r, nil
 }

 type localVariable struct {
 	namePrefix string
 	name_      string
 	value_     *ninjaString
 }

 func (l *localVariable) packageContext() *PackageContext {
 	return nil
 }

 func (l *localVariable) name() string {
 	return l.name_
 }

 func (l *localVariable) fullName(pkgNames map[*PackageContext]string) string {
 	return l.namePrefix + l.name_
 }

 func (l *localVariable) value(interface{}) (*ninjaString, error) {
 	return l.value_, nil
 }

 func (l *localVariable) String() string {
 	return "<local var>:" + l.namePrefix + l.name_
 }

 type localRule struct {
 	namePrefix string
 	name_      string
 	def_       *ruleDef
 	argNames   map[string]bool
 	scope_     *basicScope
 }

 func (l *localRule) packageContext() *PackageContext {
 	return nil
 }

 func (l *localRule) name() string {
 	return l.name_
 }

 func (l *localRule) fullName(pkgNames map[*PackageContext]string) string {
 	return l.namePrefix + l.name_
 }

 func (l *localRule) def(interface{}) (*ruleDef, error) {
 	return l.def_, nil
 }

 func (r *localRule) scope() *basicScope {
 	return r.scope_
 }

 func (r *localRule) isArg(argName string) bool {
 	return r.argNames[argName]
 }

 func (r *localRule) String() string {
 	return "<local rule>:" + r.namePrefix + r.name_
 }
	// Copyright 2014 Google Inc. All rights reserved.
	//
	// Licensed under the Apache License, Version 2.0 (the "License");
	// you may not use this file except in compliance with the License.
	// You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS,
	// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	// See the License for the specific language governing permissions and
	// limitations under the License.

	package blueprint

	import (
	"fmt"
	"strings"
	"unicode"
	"unicode/utf8"
	)

	// A Variable represents a global Ninja variable definition that will be written
	// to the output .ninja file. A variable may contain references to other global
	// Ninja variables, but circular variable references are not allowed.
	type Variable interface {
	packageContext() *PackageContext
	name() string // "foo"
	fullName(pkgNames map[*PackageContext]string) string // "pkg.foo" or "path.to.pkg.foo"
	value(config interface{}) (*ninjaString, error)
	String() string
	}

	// A Pool represents a Ninja pool that will be written to the output .ninja
	// file.
	type Pool interface {
	packageContext() *PackageContext
	name() string // "foo"
	fullName(pkgNames map[*PackageContext]string) string // "pkg.foo" or "path.to.pkg.foo"
	def(config interface{}) (*poolDef, error)
	String() string
	}

	// A Rule represents a Ninja build rule that will be written to the output
	// .ninja file.
	type Rule interface {
	packageContext() *PackageContext
	name() string // "foo"
	fullName(pkgNames map[*PackageContext]string) string // "pkg.foo" or "path.to.pkg.foo"
	def(config interface{}) (*ruleDef, error)
	scope() *basicScope
	isArg(argName string) bool
	String() string
	}

	type basicScope struct {
	parent *basicScope
	variables map[string]Variable
	pools map[string]Pool
	rules map[string]Rule
	imports map[string]*basicScope
	}

	func newScope(parent basicScope) basicScope {
	return &basicScope{
	parent: parent,
	variables: make(map[string]Variable),
	pools: make(map[string]Pool),
	rules: make(map[string]Rule),
	imports: make(map[string]*basicScope),
	}
	}

	func makeRuleScope(parent basicScope, argNames map[string]bool) basicScope {
	scope := newScope(parent)
	for argName := range argNames {
	_, err := scope.LookupVariable(argName)
	if err != nil {
	arg := &argVariable{argName}
	err = scope.AddVariable(arg)
	if err != nil {
	// This should not happen. We should have already checked that
	// the name is valid and that the scope doesn't have a variable
	// with this name.
	panic(err)
	}
	}
	}

	// We treat built-in variables like arguments for the purpose of this scope.
	for _, builtin := range builtinRuleArgs {
	arg := &argVariable{builtin}
	err := scope.AddVariable(arg)
	if err != nil {
	panic(err)
	}
	}

	return scope
	}

	func (s *basicScope) LookupVariable(name string) (Variable, error) {
	dotIndex := strings.IndexRune(name, '.')
	if dotIndex >= 0 {
	// The variable name looks like "pkg.var"
	if dotIndex+1 == len(name) {
	return nil, fmt.Errorf("variable name %q ends with a '.'", name)
	}
	if strings.ContainsRune(name[dotIndex+1:], '.') {
	return nil, fmt.Errorf("variable name %q contains multiple '.' "+
	"characters", name)
	}

	pkgName := name[:dotIndex]
	varName := name[dotIndex+1:]

	first, _ := utf8.DecodeRuneInString(varName)
	if !unicode.IsUpper(first) {
	return nil, fmt.Errorf("cannot refer to unexported name %q", name)
	}

	importedScope, err := s.lookupImportedScope(pkgName)
	if err != nil {
	return nil, err
	}

	v, ok := importedScope.variables[varName]
	if !ok {
	return nil, fmt.Errorf("package %q does not contain variable %q",
	pkgName, varName)
	}

	return v, nil
	} else {
	// The variable name has no package part; just "var"
	for ; s != nil; s = s.parent {
	v, ok := s.variables[name]
	if ok {
	return v, nil
	}
	}
	return nil, fmt.Errorf("undefined variable %q", name)
	}
	}

	func (s *basicScope) IsRuleVisible(rule Rule) bool {
	_, isBuiltin := rule.(*builtinRule)
	if isBuiltin {
	return true
	}

	name := rule.name()

	for s != nil {
	if s.rules[name] == rule {
	return true
	}

	for _, import_ := range s.imports {
	if import_.rules[name] == rule {
	return true
	}
	}

	s = s.parent
	}

	return false
	}

	func (s *basicScope) IsPoolVisible(pool Pool) bool {
	name := pool.name()

	for s != nil {
	if s.pools[name] == pool {
	return true
	}

	for _, import_ := range s.imports {
	if import_.pools[name] == pool {
	return true
	}
	}

	s = s.parent
	}

	return false
	}

	func (s basicScope) lookupImportedScope(pkgName string) (basicScope, error) {
	for ; s != nil; s = s.parent {
	importedScope, ok := s.imports[pkgName]
	if ok {
	return importedScope, nil
	}
	}
	return nil, fmt.Errorf("unknown imported package %q (missing call to "+
	"blueprint.Import()?)", pkgName)
	}

	func (s basicScope) AddImport(name string, importedScope basicScope) error {
	_, present := s.imports[name]
	if present {
	return fmt.Errorf("import %q is already defined in this scope", name)
	}
	s.imports[name] = importedScope
	return nil
	}

	func (s *basicScope) AddVariable(v Variable) error {
	name := v.name()
	_, present := s.variables[name]
	if present {
	return fmt.Errorf("variable %q is already defined in this scope", name)
	}
	s.variables[name] = v
	return nil
	}

	func (s *basicScope) AddPool(p Pool) error {
	name := p.name()
	_, present := s.pools[name]
	if present {
	return fmt.Errorf("pool %q is already defined in this scope", name)
	}
	s.pools[name] = p
	return nil
	}

	func (s *basicScope) AddRule(r Rule) error {
	name := r.name()
	_, present := s.rules[name]
	if present {
	return fmt.Errorf("rule %q is already defined in this scope", name)
	}
	s.rules[name] = r
	return nil
	}

	type localScope struct {
	namePrefix string
	scope *basicScope
	}

	func newLocalScope(parent basicScope, namePrefix string) localScope {
	return &localScope{
	namePrefix: namePrefix,
	scope: newScope(parent),
	}
	}

	// ReparentTo sets the localScope's parent scope to the scope of the given
	// package context. This allows a ModuleContext and SingletonContext to call
	// a function defined in a different Go package and have that function retain
	// access to all of the package-scoped variables of its own package.
	func (s localScope) ReparentTo(pctx PackageContext) {
	s.scope.parent = pctx.scope
	}

	func (s *localScope) LookupVariable(name string) (Variable, error) {
	return s.scope.LookupVariable(name)
	}

	func (s *localScope) IsRuleVisible(rule Rule) bool {
	return s.scope.IsRuleVisible(rule)
	}

	func (s *localScope) IsPoolVisible(pool Pool) bool {
	return s.scope.IsPoolVisible(pool)
	}

	func (s localScope) AddLocalVariable(name, value string) (localVariable,
	error) {

	err := validateNinjaName(name)
	if err != nil {
	return nil, err
	}

	if strings.ContainsRune(name, '.') {
	return nil, fmt.Errorf("local variable name %q contains '.'", name)
	}

	ninjaValue, err := parseNinjaString(s.scope, value)
	if err != nil {
	return nil, err
	}

	v := &localVariable{
	namePrefix: s.namePrefix,
	name_: name,
	value_: ninjaValue,
	}

	err = s.scope.AddVariable(v)
	if err != nil {
	return nil, err
	}

	return v, nil
	}

	func (s localScope) AddLocalRule(name string, params RuleParams,
	argNames ...string) (*localRule, error) {

	err := validateNinjaName(name)
	if err != nil {
	return nil, err
	}

	err = validateArgNames(argNames)
	if err != nil {
	return nil, fmt.Errorf("invalid argument name: %s", err)
	}

	argNamesSet := make(map[string]bool)
	for _, argName := range argNames {
	argNamesSet[argName] = true
	}

	ruleScope := makeRuleScope(s.scope, argNamesSet)

	def, err := parseRuleParams(ruleScope, params)
	if err != nil {
	return nil, err
	}

	r := &localRule{
	namePrefix: s.namePrefix,
	name_: name,
	def_: def,
	argNames: argNamesSet,
	scope_: ruleScope,
	}

	err = s.scope.AddRule(r)
	if err != nil {
	return nil, err
	}

	return r, nil
	}

	type localVariable struct {
	namePrefix string
	name_ string
	value_ *ninjaString
	}

	func (l localVariable) packageContext() PackageContext {
	return nil
	}

	func (l *localVariable) name() string {
	return l.name_
	}

	func (l localVariable) fullName(pkgNames map[PackageContext]string) string {
	return l.namePrefix + l.name_
	}

	func (l localVariable) value(interface{}) (ninjaString, error) {
	return l.value_, nil
	}

	func (l *localVariable) String() string {
	return "<local var>:" + l.namePrefix + l.name_
	}

	type localRule struct {
	namePrefix string
	name_ string
	def_ *ruleDef
	argNames map[string]bool
	scope_ *basicScope
	}

	func (l localRule) packageContext() PackageContext {
	return nil
	}

	func (l *localRule) name() string {
	return l.name_
	}

	func (l localRule) fullName(pkgNames map[PackageContext]string) string {
	return l.namePrefix + l.name_
	}

	func (l localRule) def(interface{}) (ruleDef, error) {
	return l.def_, nil
	}

	func (r localRule) scope() basicScope {
	return r.scope_
	}

	func (r *localRule) isArg(argName string) bool {
	return r.argNames[argName]
	}

	func (r *localRule) String() string {
	return "<local rule>:" + r.namePrefix + r.name_
	}