1// Copyright 2016 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 proptools
16
17import "strings"
18
19// NinjaEscapeList takes a slice of strings that may contain characters that are meaningful to ninja
20// ($), and escapes each string so they will be passed to bash.  It is not necessary on input,
21// output, or dependency names, those are handled by ModuleContext.Build.  It is generally required
22// on strings from properties in Blueprint files that are used as Args to ModuleContext.Build.  A
23// new slice containing the escaped strings is returned.
24func NinjaEscapeList(slice []string) []string {
25	slice = append([]string(nil), slice...)
26	for i, s := range slice {
27		slice[i] = NinjaEscape(s)
28	}
29	return slice
30}
31
32// NinjaEscapeList takes a string that may contain characters that are meaningful to ninja
33// ($), and escapes it so it will be passed to bash.  It is not necessary on input,
34// output, or dependency names, those are handled by ModuleContext.Build.  It is generally required
35// on strings from properties in Blueprint files that are used as Args to ModuleContext.Build.  A
36// new slice containing the escaped strings is returned.
37func NinjaEscape(s string) string {
38	return ninjaEscaper.Replace(s)
39}
40
41var ninjaEscaper = strings.NewReplacer(
42	"$", "$$")
43
44// ShellEscapeList takes a slice of strings that may contain characters that are meaningful to bash and
45// escapes them if necessary by wrapping them in single quotes, and replacing internal single quotes with
46// '\'' (one single quote to end the quoting, a shell-escaped single quote to insert a real single
47// quote, and then a single quote to restarting quoting.  A new slice containing the escaped strings
48// is returned.
49func ShellEscapeList(slice []string) []string {
50	slice = append([]string(nil), slice...)
51
52	for i, s := range slice {
53		slice[i] = ShellEscape(s)
54	}
55	return slice
56
57}
58
59func shellUnsafeChar(r rune) bool {
60	switch {
61	case 'A' <= r && r <= 'Z',
62		'a' <= r && r <= 'z',
63		'0' <= r && r <= '9',
64		r == '_',
65		r == '+',
66		r == '-',
67		r == '=',
68		r == '.',
69		r == ',',
70		r == '/':
71		return false
72	default:
73		return true
74	}
75}
76
77// ShellEscape takes string that may contain characters that are meaningful to bash and
78// escapes it if necessary by wrapping it in single quotes, and replacing internal single quotes with
79// '\'' (one single quote to end the quoting, a shell-escaped single quote to insert a real single
80// quote, and then a single quote to restarting quoting.
81func ShellEscape(s string) string {
82	shellUnsafeCharNotSpace := func(r rune) bool {
83		return r != ' ' && shellUnsafeChar(r)
84	}
85
86	if strings.IndexFunc(s, shellUnsafeCharNotSpace) == -1 {
87		// No escaping necessary
88		return s
89	}
90
91	return `'` + singleQuoteReplacer.Replace(s) + `'`
92}
93
94// ShellEscapeIncludingSpaces escapes the input `s` in a similar way to ShellEscape except that
95// this treats spaces as meaningful characters.
96func ShellEscapeIncludingSpaces(s string) string {
97	if strings.IndexFunc(s, shellUnsafeChar) == -1 {
98		// No escaping necessary
99		return s
100	}
101
102	return `'` + singleQuoteReplacer.Replace(s) + `'`
103}
104
105func NinjaAndShellEscapeList(slice []string) []string {
106	return ShellEscapeList(NinjaEscapeList(slice))
107}
108
109func NinjaAndShellEscape(s string) string {
110	return ShellEscape(NinjaEscape(s))
111}
112
113var singleQuoteReplacer = strings.NewReplacer(`'`, `'\''`)
114