var.go - platform/build/kati - Git at Google

 // Copyright 2015 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 kati

 import (
 	"bytes"
 	"fmt"
 	"io"
 	"strings"
 )

 // Var is an interface of make variable.
 type Var interface {
 	Value
 	Append(*Evaluator, string) (Var, error)
 	AppendVar(*Evaluator, Value) (Var, error)
 	Flavor() string
 	Origin() string
 	IsDefined() bool
 }

 type targetSpecificVar struct {
 	v  Var
 	op string
 }

 func (v *targetSpecificVar) Append(ev *Evaluator, s string) (Var, error) {
 	nv, err := v.v.Append(ev, s)
 	if err != nil {
 		return nil, err
 	}
 	return &targetSpecificVar{
 		v:  nv,
 		op: v.op,
 	}, nil
 }
 func (v *targetSpecificVar) AppendVar(ev *Evaluator, v2 Value) (Var, error) {
 	nv, err := v.v.AppendVar(ev, v2)
 	if err != nil {
 		return nil, err
 	}
 	return &targetSpecificVar{
 		v:  nv,
 		op: v.op,
 	}, nil
 }
 func (v *targetSpecificVar) Flavor() string {
 	return v.v.Flavor()
 }
 func (v *targetSpecificVar) Origin() string {
 	return v.v.Origin()
 }
 func (v *targetSpecificVar) IsDefined() bool {
 	return v.v.IsDefined()
 }
 func (v *targetSpecificVar) String() string {
 	// TODO: If we add the info of |op| a test starts
 	// failing. Shouldn't we use this only for debugging?
 	return v.v.String()
 	// return v.v.String() + " (op=" + v.op + ")"
 }
 func (v *targetSpecificVar) Eval(w evalWriter, ev *Evaluator) error {
 	return v.v.Eval(w, ev)
 }

 func (v *targetSpecificVar) serialize() serializableVar {
 	return serializableVar{
 		Type:     v.op,
 		Children: []serializableVar{v.v.serialize()},
 	}
 }

 func (v *targetSpecificVar) dump(d *dumpbuf) {
 	d.Byte(valueTypeTSV)
 	d.Str(v.op)
 	v.v.dump(d)
 }

 type simpleVar struct {
 	// space separated. note that each string may contain spaces, so
 	// it is not word list.
 	value  []string
 	origin string
 }

 func (v *simpleVar) Flavor() string  { return "simple" }
 func (v *simpleVar) Origin() string  { return v.origin }
 func (v *simpleVar) IsDefined() bool { return true }

 func (v *simpleVar) String() string { return strings.Join(v.value, " ") }
 func (v *simpleVar) Eval(w evalWriter, ev *Evaluator) error {
 	space := false
 	for _, v := range v.value {
 		if space {
 			writeByte(w, ' ')
 		}
 		io.WriteString(w, v)
 		space = true
 	}
 	return nil
 }
 func (v *simpleVar) serialize() serializableVar {
 	return serializableVar{
 		Type:   "simple",
 		V:      v.String(),
 		Origin: v.origin,
 	}
 }
 func (v *simpleVar) dump(d *dumpbuf) {
 	d.Byte(valueTypeSimple)
 	d.Int(len(v.value))
 	for _, v := range v.value {
 		d.Str(v)
 	}
 	d.Str(v.origin)
 }

 func (v *simpleVar) Append(ev *Evaluator, s string) (Var, error) {
 	val, _, err := parseExpr([]byte(s), nil, parseOp{})
 	if err != nil {
 		return nil, err
 	}
 	abuf := newEbuf()
 	err = val.Eval(abuf, ev)
 	if err != nil {
 		return nil, err
 	}
 	v.value = append(v.value, abuf.String())
 	abuf.release()
 	return v, nil
 }

 func (v *simpleVar) AppendVar(ev *Evaluator, val Value) (Var, error) {
 	abuf := newEbuf()
 	err := val.Eval(abuf, ev)
 	if err != nil {
 		return nil, err
 	}
 	v.value = append(v.value, abuf.String())
 	abuf.release()
 	return v, nil
 }

 type automaticVar struct {
 	value []byte
 }

 func (v *automaticVar) Flavor() string  { return "simple" }
 func (v *automaticVar) Origin() string  { return "automatic" }
 func (v *automaticVar) IsDefined() bool { return true }

 func (v *automaticVar) String() string { return string(v.value) }
 func (v *automaticVar) Eval(w evalWriter, ev *Evaluator) error {
 	w.Write(v.value)
 	return nil
 }
 func (v *automaticVar) serialize() serializableVar {
 	return serializableVar{Type: ""}
 }
 func (v *automaticVar) dump(d *dumpbuf) {
 	d.err = fmt.Errorf("cannnot dump automatic var:%s", v.value)
 }

 func (v *automaticVar) Append(ev *Evaluator, s string) (Var, error) {
 	val, _, err := parseExpr([]byte(s), nil, parseOp{})
 	if err != nil {
 		return nil, err
 	}
 	abuf := newEbuf()
 	err = val.Eval(abuf, ev)
 	if err != nil {
 		return nil, err
 	}
 	value := []string{string(v.value), abuf.String()}
 	abuf.release()
 	return &simpleVar{
 		value:  value,
 		origin: "file",
 	}, nil
 }

 func (v *automaticVar) AppendVar(ev *Evaluator, val Value) (Var, error) {
 	abuf := newEbuf()
 	err := val.Eval(abuf, ev)
 	if err != nil {
 		return nil, err
 	}
 	value := []string{string(v.value), abuf.String()}
 	abuf.release()
 	return &simpleVar{
 		value:  value,
 		origin: "file",
 	}, nil
 }

 type recursiveVar struct {
 	expr   Value
 	origin string
 }

 func (v *recursiveVar) Flavor() string  { return "recursive" }
 func (v *recursiveVar) Origin() string  { return v.origin }
 func (v *recursiveVar) IsDefined() bool { return true }

 func (v *recursiveVar) String() string { return v.expr.String() }
 func (v *recursiveVar) Eval(w evalWriter, ev *Evaluator) error {
 	v.expr.Eval(w, ev)
 	return nil
 }
 func (v *recursiveVar) serialize() serializableVar {
 	return serializableVar{
 		Type:     "recursive",
 		Children: []serializableVar{v.expr.serialize()},
 		Origin:   v.origin,
 	}
 }
 func (v *recursiveVar) dump(d *dumpbuf) {
 	d.Byte(valueTypeRecursive)
 	v.expr.dump(d)
 	d.Str(v.origin)
 }

 func (v *recursiveVar) Append(_ *Evaluator, s string) (Var, error) {
 	var exp expr
 	if e, ok := v.expr.(expr); ok {
 		exp = append(e, literal(" "))
 	} else {
 		exp = expr{v.expr, literal(" ")}
 	}
 	sv, _, err := parseExpr([]byte(s), nil, parseOp{alloc: true})
 	if err != nil {
 		return nil, err
 	}
 	if aexpr, ok := sv.(expr); ok {
 		exp = append(exp, aexpr...)
 	} else {
 		exp = append(exp, sv)
 	}
 	v.expr = exp
 	return v, nil
 }

 func (v *recursiveVar) AppendVar(ev *Evaluator, val Value) (Var, error) {
 	var buf bytes.Buffer
 	buf.WriteString(v.expr.String())
 	buf.WriteByte(' ')
 	buf.WriteString(val.String())
 	e, _, err := parseExpr(buf.Bytes(), nil, parseOp{alloc: true})
 	if err != nil {
 		return nil, err
 	}
 	v.expr = e
 	return v, nil
 }

 type undefinedVar struct{}

 func (undefinedVar) Flavor() string  { return "undefined" }
 func (undefinedVar) Origin() string  { return "undefined" }
 func (undefinedVar) IsDefined() bool { return false }
 func (undefinedVar) String() string  { return "" }
 func (undefinedVar) Eval(_ evalWriter, _ *Evaluator) error {
 	return nil
 }
 func (undefinedVar) serialize() serializableVar {
 	return serializableVar{Type: "undefined"}
 }
 func (undefinedVar) dump(d *dumpbuf) {
 	d.Byte(valueTypeUndefined)
 }

 func (undefinedVar) Append(*Evaluator, string) (Var, error) {
 	return undefinedVar{}, nil
 }

 func (undefinedVar) AppendVar(_ *Evaluator, val Value) (Var, error) {
 	return undefinedVar{}, nil
 }

 // Vars is a map for make variables.
 type Vars map[string]Var

 // usedEnvs tracks what environment variables are used.
 var usedEnvs = map[string]bool{}

 // Lookup looks up named make variable.
 func (vt Vars) Lookup(name string) Var {
 	if v, ok := vt[name]; ok {
 		if strings.HasPrefix(v.Origin(), "environment") {
 			usedEnvs[name] = true
 		}
 		return v
 	}
 	return undefinedVar{}
 }

 // origin precedence
 //  override / environment override
 //  command line
 //  file
 //  environment
 //  default
 // TODO(ukai): is this correct order?
 var originPrecedence = map[string]int{
 	"override":             4,
 	"environment override": 4,
 	"command line":         3,
 	"file":                 2,
 	"environment":          2,
 	"default":              1,
 	"undefined":            0,
 	"automatic":            0,
 }

 // Assign assigns v to name.
 func (vt Vars) Assign(name string, v Var) {
 	vo := v.Origin()
 	// assign automatic always win.
 	// assign new value to automatic always win.
 	if vo != "automatic" {
 		vp := originPrecedence[v.Origin()]
 		var op int
 		if ov, ok := vt[name]; ok {
 			op = originPrecedence[ov.Origin()]
 		}
 		if op > vp {
 			return
 		}
 	}
 	vt[name] = v
 }

 // NewVars creates new Vars.
 func NewVars(vt Vars) Vars {
 	r := make(Vars)
 	r.Merge(vt)
 	return r
 }

 // Merge merges vt2 into vt.
 func (vt Vars) Merge(vt2 Vars) {
 	for k, v := range vt2 {
 		vt[k] = v
 	}
 }

 // save saves value of the variable named name.
 // calling returned value will restore to the old value at the time
 // when save called.
 func (vt Vars) save(name string) func() {
 	if v, ok := vt[name]; ok {
 		return func() {
 			vt[name] = v
 		}
 	}
 	return func() {
 		delete(vt, name)
 	}
 }
	// Copyright 2015 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 kati

	import (
	"bytes"
	"fmt"
	"io"
	"strings"
	)

	// Var is an interface of make variable.
	type Var interface {
	Value
	Append(*Evaluator, string) (Var, error)
	AppendVar(*Evaluator, Value) (Var, error)
	Flavor() string
	Origin() string
	IsDefined() bool
	}

	type targetSpecificVar struct {
	v Var
	op string
	}

	func (v targetSpecificVar) Append(ev Evaluator, s string) (Var, error) {
	nv, err := v.v.Append(ev, s)
	if err != nil {
	return nil, err
	}
	return &targetSpecificVar{
	v: nv,
	op: v.op,
	}, nil
	}
	func (v targetSpecificVar) AppendVar(ev Evaluator, v2 Value) (Var, error) {
	nv, err := v.v.AppendVar(ev, v2)
	if err != nil {
	return nil, err
	}
	return &targetSpecificVar{
	v: nv,
	op: v.op,
	}, nil
	}
	func (v *targetSpecificVar) Flavor() string {
	return v.v.Flavor()
	}
	func (v *targetSpecificVar) Origin() string {
	return v.v.Origin()
	}
	func (v *targetSpecificVar) IsDefined() bool {
	return v.v.IsDefined()
	}
	func (v *targetSpecificVar) String() string {
	// TODO: If we add the info of \|op\| a test starts
	// failing. Shouldn't we use this only for debugging?
	return v.v.String()
	// return v.v.String() + " (op=" + v.op + ")"
	}
	func (v targetSpecificVar) Eval(w evalWriter, ev Evaluator) error {
	return v.v.Eval(w, ev)
	}

	func (v *targetSpecificVar) serialize() serializableVar {
	return serializableVar{
	Type: v.op,
	Children: []serializableVar{v.v.serialize()},
	}
	}

	func (v targetSpecificVar) dump(d dumpbuf) {
	d.Byte(valueTypeTSV)
	d.Str(v.op)
	v.v.dump(d)
	}

	type simpleVar struct {
	// space separated. note that each string may contain spaces, so
	// it is not word list.
	value []string
	origin string
	}

	func (v *simpleVar) Flavor() string { return "simple" }
	func (v *simpleVar) Origin() string { return v.origin }
	func (v *simpleVar) IsDefined() bool { return true }

	func (v *simpleVar) String() string { return strings.Join(v.value, " ") }
	func (v simpleVar) Eval(w evalWriter, ev Evaluator) error {
	space := false
	for _, v := range v.value {
	if space {
	writeByte(w, ' ')
	}
	io.WriteString(w, v)
	space = true
	}
	return nil
	}
	func (v *simpleVar) serialize() serializableVar {
	return serializableVar{
	Type: "simple",
	V: v.String(),
	Origin: v.origin,
	}
	}
	func (v simpleVar) dump(d dumpbuf) {
	d.Byte(valueTypeSimple)
	d.Int(len(v.value))
	for _, v := range v.value {
	d.Str(v)
	}
	d.Str(v.origin)
	}

	func (v simpleVar) Append(ev Evaluator, s string) (Var, error) {
	val, _, err := parseExpr([]byte(s), nil, parseOp{})
	if err != nil {
	return nil, err
	}
	abuf := newEbuf()
	err = val.Eval(abuf, ev)
	if err != nil {
	return nil, err
	}
	v.value = append(v.value, abuf.String())
	abuf.release()
	return v, nil
	}

	func (v simpleVar) AppendVar(ev Evaluator, val Value) (Var, error) {
	abuf := newEbuf()
	err := val.Eval(abuf, ev)
	if err != nil {
	return nil, err
	}
	v.value = append(v.value, abuf.String())
	abuf.release()
	return v, nil
	}

	type automaticVar struct {
	value []byte
	}

	func (v *automaticVar) Flavor() string { return "simple" }
	func (v *automaticVar) Origin() string { return "automatic" }
	func (v *automaticVar) IsDefined() bool { return true }

	func (v *automaticVar) String() string { return string(v.value) }
	func (v automaticVar) Eval(w evalWriter, ev Evaluator) error {
	w.Write(v.value)
	return nil
	}
	func (v *automaticVar) serialize() serializableVar {
	return serializableVar{Type: ""}
	}
	func (v automaticVar) dump(d dumpbuf) {
	d.err = fmt.Errorf("cannnot dump automatic var:%s", v.value)
	}

	func (v automaticVar) Append(ev Evaluator, s string) (Var, error) {
	val, _, err := parseExpr([]byte(s), nil, parseOp{})
	if err != nil {
	return nil, err
	}
	abuf := newEbuf()
	err = val.Eval(abuf, ev)
	if err != nil {
	return nil, err
	}
	value := []string{string(v.value), abuf.String()}
	abuf.release()
	return &simpleVar{
	value: value,
	origin: "file",
	}, nil
	}

	func (v automaticVar) AppendVar(ev Evaluator, val Value) (Var, error) {
	abuf := newEbuf()
	err := val.Eval(abuf, ev)
	if err != nil {
	return nil, err
	}
	value := []string{string(v.value), abuf.String()}
	abuf.release()
	return &simpleVar{
	value: value,
	origin: "file",
	}, nil
	}

	type recursiveVar struct {
	expr Value
	origin string
	}

	func (v *recursiveVar) Flavor() string { return "recursive" }
	func (v *recursiveVar) Origin() string { return v.origin }
	func (v *recursiveVar) IsDefined() bool { return true }

	func (v *recursiveVar) String() string { return v.expr.String() }
	func (v recursiveVar) Eval(w evalWriter, ev Evaluator) error {
	v.expr.Eval(w, ev)
	return nil
	}
	func (v *recursiveVar) serialize() serializableVar {
	return serializableVar{
	Type: "recursive",
	Children: []serializableVar{v.expr.serialize()},
	Origin: v.origin,
	}
	}
	func (v recursiveVar) dump(d dumpbuf) {
	d.Byte(valueTypeRecursive)
	v.expr.dump(d)
	d.Str(v.origin)
	}

	func (v recursiveVar) Append(_ Evaluator, s string) (Var, error) {
	var exp expr
	if e, ok := v.expr.(expr); ok {
	exp = append(e, literal(" "))
	} else {
	exp = expr{v.expr, literal(" ")}
	}
	sv, _, err := parseExpr([]byte(s), nil, parseOp{alloc: true})
	if err != nil {
	return nil, err
	}
	if aexpr, ok := sv.(expr); ok {
	exp = append(exp, aexpr...)
	} else {
	exp = append(exp, sv)
	}
	v.expr = exp
	return v, nil
	}

	func (v recursiveVar) AppendVar(ev Evaluator, val Value) (Var, error) {
	var buf bytes.Buffer
	buf.WriteString(v.expr.String())
	buf.WriteByte(' ')
	buf.WriteString(val.String())
	e, _, err := parseExpr(buf.Bytes(), nil, parseOp{alloc: true})
	if err != nil {
	return nil, err
	}
	v.expr = e
	return v, nil
	}

	type undefinedVar struct{}

	func (undefinedVar) Flavor() string { return "undefined" }
	func (undefinedVar) Origin() string { return "undefined" }
	func (undefinedVar) IsDefined() bool { return false }
	func (undefinedVar) String() string { return "" }
	func (undefinedVar) Eval(_ evalWriter, _ *Evaluator) error {
	return nil
	}
	func (undefinedVar) serialize() serializableVar {
	return serializableVar{Type: "undefined"}
	}
	func (undefinedVar) dump(d *dumpbuf) {
	d.Byte(valueTypeUndefined)
	}

	func (undefinedVar) Append(*Evaluator, string) (Var, error) {
	return undefinedVar{}, nil
	}

	func (undefinedVar) AppendVar(_ *Evaluator, val Value) (Var, error) {
	return undefinedVar{}, nil
	}

	// Vars is a map for make variables.
	type Vars map[string]Var

	// usedEnvs tracks what environment variables are used.
	var usedEnvs = map[string]bool{}

	// Lookup looks up named make variable.
	func (vt Vars) Lookup(name string) Var {
	if v, ok := vt[name]; ok {
	if strings.HasPrefix(v.Origin(), "environment") {
	usedEnvs[name] = true
	}
	return v
	}
	return undefinedVar{}
	}

	// origin precedence
	// override / environment override
	// command line
	// file
	// environment
	// default
	// TODO(ukai): is this correct order?
	var originPrecedence = map[string]int{
	"override": 4,
	"environment override": 4,
	"command line": 3,
	"file": 2,
	"environment": 2,
	"default": 1,
	"undefined": 0,
	"automatic": 0,
	}

	// Assign assigns v to name.
	func (vt Vars) Assign(name string, v Var) {
	vo := v.Origin()
	// assign automatic always win.
	// assign new value to automatic always win.
	if vo != "automatic" {
	vp := originPrecedence[v.Origin()]
	var op int
	if ov, ok := vt[name]; ok {
	op = originPrecedence[ov.Origin()]
	}
	if op > vp {
	return
	}
	}
	vt[name] = v
	}

	// NewVars creates new Vars.
	func NewVars(vt Vars) Vars {
	r := make(Vars)
	r.Merge(vt)
	return r
	}

	// Merge merges vt2 into vt.
	func (vt Vars) Merge(vt2 Vars) {
	for k, v := range vt2 {
	vt[k] = v
	}
	}

	// save saves value of the variable named name.
	// calling returned value will restore to the old value at the time
	// when save called.
	func (vt Vars) save(name string) func() {
	if v, ok := vt[name]; ok {
	return func() {
	vt[name] = v
	}
	}
	return func() {
	delete(vt, name)
	}
	}