1// Copyright 2018 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 makedeps
16
17import (
18	"bytes"
19	"fmt"
20	"io"
21	"strings"
22
23	"android/soong/androidmk/parser"
24)
25
26type Deps struct {
27	Output string
28	Inputs []string
29}
30
31func Parse(filename string, r io.Reader) (*Deps, error) {
32	p := parser.NewParser(filename, r)
33	nodes, errs := p.Parse()
34
35	if len(errs) == 1 {
36		return nil, errs[0]
37	} else if len(errs) > 1 {
38		return nil, fmt.Errorf("many errors: %v", errs)
39	}
40
41	pos := func(node parser.Node) string {
42		return p.Unpack(node.Pos()).String() + ": "
43	}
44
45	ret := &Deps{}
46
47	for _, node := range nodes {
48		switch x := node.(type) {
49		case *parser.Comment:
50			// Do nothing
51		case *parser.Rule:
52			if x.Recipe != "" {
53				return nil, fmt.Errorf("%sunexpected recipe in rule: %v", pos(node), x)
54			}
55
56			if !x.Target.Const() {
57				return nil, fmt.Errorf("%sunsupported variable expansion: %v", pos(node), x.Target.Dump())
58			}
59			outputs := x.Target.Words()
60			if len(outputs) > 0 {
61				ret.Output = outputs[0].Value(nil)
62			} else {
63				// TODO(b/141372861): put this back
64				//return nil, fmt.Errorf("%smissing output: %v", pos(node), x)
65			}
66
67			if !x.Prerequisites.Const() {
68				return nil, fmt.Errorf("%sunsupported variable expansion: %v", pos(node), x.Prerequisites.Dump())
69			}
70			for _, input := range x.Prerequisites.Words() {
71				ret.Inputs = append(ret.Inputs, input.Value(nil))
72			}
73		default:
74			return nil, fmt.Errorf("%sunexpected line: %#v", pos(node), node)
75		}
76	}
77
78	return ret, nil
79}
80
81func (d *Deps) Print() []byte {
82	// We don't really have to escape every \, but it's simpler,
83	// and ninja will handle it.
84	replacer := strings.NewReplacer(" ", "\\ ",
85		":", "\\:",
86		"#", "\\#",
87		"$", "$$",
88		"\\", "\\\\")
89
90	b := &bytes.Buffer{}
91	fmt.Fprintf(b, "%s:", replacer.Replace(d.Output))
92	for _, input := range d.Inputs {
93		fmt.Fprintf(b, " %s", replacer.Replace(input))
94	}
95	fmt.Fprintln(b)
96	return b.Bytes()
97}
98