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1// Copyright 2015 Google Inc. All rights reserved
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//      http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15package kati
16
17import (
18	"strings"
19
20	"github.com/golang/glog"
21)
22
23type ast interface {
24	eval(*Evaluator) error
25	show()
26}
27
28type assignAST struct {
29	srcpos
30	lhs Value
31	rhs Value
32	op  string
33	opt string // "override", "export"
34}
35
36func (ast *assignAST) eval(ev *Evaluator) error {
37	return ev.evalAssign(ast)
38}
39
40func (ast *assignAST) evalRHS(ev *Evaluator, lhs string) (Var, error) {
41	origin := "file"
42	if ast.filename == bootstrapMakefileName {
43		origin = "default"
44	}
45	if ast.opt == "override" {
46		origin = "override"
47	}
48	// TODO(ukai): handle ast.opt == "export"
49	switch ast.op {
50	case ":=":
51		switch v := ast.rhs.(type) {
52		case literal:
53			return &simpleVar{value: []string{v.String()}, origin: origin}, nil
54		case tmpval:
55			return &simpleVar{value: []string{v.String()}, origin: origin}, nil
56		default:
57			var buf evalBuffer
58			buf.resetSep()
59			err := v.Eval(&buf, ev)
60			if err != nil {
61				return nil, err
62			}
63			return &simpleVar{value: []string{buf.String()}, origin: origin}, nil
64		}
65	case "=":
66		return &recursiveVar{expr: ast.rhs, origin: origin}, nil
67	case "+=":
68		prev := ev.lookupVarInCurrentScope(lhs)
69		if !prev.IsDefined() {
70			return &recursiveVar{expr: ast.rhs, origin: origin}, nil
71		}
72		return prev.AppendVar(ev, ast.rhs)
73	case "?=":
74		prev := ev.lookupVarInCurrentScope(lhs)
75		if prev.IsDefined() {
76			return prev, nil
77		}
78		return &recursiveVar{expr: ast.rhs, origin: origin}, nil
79	}
80	return nil, ast.errorf("unknown assign op: %q", ast.op)
81}
82
83func (ast *assignAST) show() {
84	glog.Infof("%s %s %s %q", ast.opt, ast.lhs, ast.op, ast.rhs)
85}
86
87// maybeRuleAST is an ast for rule line.
88// Note we cannot be sure what this is, until all variables in |expr|
89// are expanded.
90type maybeRuleAST struct {
91	srcpos
92	isRule bool // found literal ':'
93	expr   Value
94	assign *assignAST // target specific var
95	semi   []byte     // after ';' if ';' exists
96}
97
98func (ast *maybeRuleAST) eval(ev *Evaluator) error {
99	return ev.evalMaybeRule(ast)
100}
101
102func (ast *maybeRuleAST) show() {
103	glog.Info(ast.expr)
104}
105
106type commandAST struct {
107	srcpos
108	cmd string
109}
110
111func (ast *commandAST) eval(ev *Evaluator) error {
112	return ev.evalCommand(ast)
113}
114
115func (ast *commandAST) show() {
116	glog.Infof("\t%s", strings.Replace(ast.cmd, "\n", `\n`, -1))
117}
118
119type includeAST struct {
120	srcpos
121	expr string
122	op   string
123}
124
125func (ast *includeAST) eval(ev *Evaluator) error {
126	return ev.evalInclude(ast)
127}
128
129func (ast *includeAST) show() {
130	glog.Infof("include %s", ast.expr)
131}
132
133type ifAST struct {
134	srcpos
135	op         string
136	lhs        Value
137	rhs        Value // Empty if |op| is ifdef or ifndef.
138	trueStmts  []ast
139	falseStmts []ast
140}
141
142func (ast *ifAST) eval(ev *Evaluator) error {
143	return ev.evalIf(ast)
144}
145
146func (ast *ifAST) show() {
147	// TODO
148	glog.Info("if")
149}
150
151type exportAST struct {
152	srcpos
153	expr     []byte
154	hasEqual bool
155	export   bool
156}
157
158func (ast *exportAST) eval(ev *Evaluator) error {
159	return ev.evalExport(ast)
160}
161
162func (ast *exportAST) show() {
163	// TODO
164	glog.Info("export")
165}
166
167type vpathAST struct {
168	srcpos
169	expr Value
170}
171
172func (ast *vpathAST) eval(ev *Evaluator) error {
173	return ev.evalVpath(ast)
174}
175
176func (ast *vpathAST) show() {
177	glog.Infof("vpath %s", ast.expr.String())
178}
179