1 // Copyright (c) 2013 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include "tools/gn/escape.h" 6 7 #include "base/containers/stack_container.h" 8 #include "base/logging.h" 9 10 namespace { 11 12 // A "1" in this lookup table means that char is valid in the Posix shell. 13 const char kShellValid[0x80] = { 14 // 00-1f: all are invalid 15 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 16 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 17 // ' ' ! " # $ % & ' ( ) * + , - . / 18 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 19 // 0 1 2 3 4 5 6 7 8 9 : ; < = > ? 20 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 0, 21 // @ A B C D E F G H I J K L M N O 22 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 23 // P Q R S T U V W X Y Z [ \ ] ^ _ 24 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 25 // ` a b c d e f g h i j k l m n o 26 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 27 // p q r s t u v w x y z { | } ~ 28 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 0 }; 29 30 // Append one character to the given string, escaping it for Ninja. 31 // 32 // Ninja's escaping rules are very simple. We always escape colons even 33 // though they're OK in many places, in case the resulting string is used on 34 // the left-hand-side of a rule. 35 template<typename DestString> 36 inline void NinjaEscapeChar(char ch, DestString* dest) { 37 if (ch == '$' || ch == ' ' || ch == ':') 38 dest->push_back('$'); 39 dest->push_back(ch); 40 } 41 42 template<typename DestString> 43 void EscapeStringToString_Ninja(const base::StringPiece& str, 44 const EscapeOptions& options, 45 DestString* dest, 46 bool* needed_quoting) { 47 for (size_t i = 0; i < str.size(); i++) 48 NinjaEscapeChar(str[i], dest); 49 if (needed_quoting) 50 *needed_quoting = false; 51 } 52 53 // Escape for CommandLineToArgvW and additionally escape Ninja characters. 54 // 55 // The basic algorithm is if the string doesn't contain any parse-affecting 56 // characters, don't do anything (other than the Ninja processing). If it does, 57 // quote the string, and backslash-escape all quotes and backslashes. 58 // See: 59 // http://blogs.msdn.com/b/twistylittlepassagesallalike/archive/2011/04/23/everyone-quotes-arguments-the-wrong-way.aspx 60 // http://blogs.msdn.com/b/oldnewthing/archive/2010/09/17/10063629.aspx 61 template<typename DestString> 62 void EscapeStringToString_WindowsNinjaFork(const base::StringPiece& str, 63 const EscapeOptions& options, 64 DestString* dest, 65 bool* needed_quoting) { 66 // We assume we don't have any whitespace chars that aren't spaces. 67 DCHECK(str.find_first_of("\r\n\v\t") == std::string::npos); 68 69 if (str.find_first_of(" \"") == std::string::npos) { 70 // Simple case, don't quote. 71 EscapeStringToString_Ninja(str, options, dest, needed_quoting); 72 } else { 73 if (!options.inhibit_quoting) 74 dest->push_back('"'); 75 76 for (size_t i = 0; i < str.size(); i++) { 77 // Count backslashes in case they're followed by a quote. 78 size_t backslash_count = 0; 79 while (i < str.size() && str[i] == '\\') { 80 i++; 81 backslash_count++; 82 } 83 if (i == str.size()) { 84 // Backslashes at end of string. Backslash-escape all of them since 85 // they'll be followed by a quote. 86 dest->append(backslash_count * 2, '\\'); 87 } else if (str[i] == '"') { 88 // 0 or more backslashes followed by a quote. Backslash-escape the 89 // backslashes, then backslash-escape the quote. 90 dest->append(backslash_count * 2 + 1, '\\'); 91 dest->push_back('"'); 92 } else { 93 // Non-special Windows character, just escape for Ninja. Also, add any 94 // backslashes we read previously, these are literals. 95 dest->append(backslash_count, '\\'); 96 NinjaEscapeChar(str[i], dest); 97 } 98 } 99 100 if (!options.inhibit_quoting) 101 dest->push_back('"'); 102 if (needed_quoting) 103 *needed_quoting = true; 104 } 105 } 106 107 template<typename DestString> 108 void EscapeStringToString_PosixNinjaFork(const base::StringPiece& str, 109 const EscapeOptions& options, 110 DestString* dest, 111 bool* needed_quoting) { 112 for (size_t i = 0; i < str.size(); i++) { 113 if (str[i] == '$' || str[i] == ' ') { 114 // Space and $ are special to both Ninja and the shell. '$' escape for 115 // Ninja, then backslash-escape for the shell. 116 dest->push_back('\\'); 117 dest->push_back('$'); 118 dest->push_back(str[i]); 119 } else if (str[i] == ':') { 120 // Colon is the only other Ninja special char, which is not special to 121 // the shell. 122 dest->push_back('$'); 123 dest->push_back(':'); 124 } else if (static_cast<unsigned>(str[i]) >= 0x80 || 125 !kShellValid[static_cast<int>(str[i])]) { 126 // All other invalid shell chars get backslash-escaped. 127 dest->push_back('\\'); 128 dest->push_back(str[i]); 129 } else { 130 // Everything else is a literal. 131 dest->push_back(str[i]); 132 } 133 } 134 } 135 136 template<typename DestString> 137 void EscapeStringToString(const base::StringPiece& str, 138 const EscapeOptions& options, 139 DestString* dest, 140 bool* needed_quoting) { 141 switch (options.mode) { 142 case ESCAPE_NONE: 143 dest->append(str.data(), str.size()); 144 break; 145 case ESCAPE_NINJA: 146 EscapeStringToString_Ninja(str, options, dest, needed_quoting); 147 break; 148 case ESCAPE_NINJA_COMMAND: 149 switch (options.platform) { 150 case ESCAPE_PLATFORM_CURRENT: 151 #if defined(OS_WIN) 152 EscapeStringToString_WindowsNinjaFork(str, options, dest, 153 needed_quoting); 154 #else 155 EscapeStringToString_PosixNinjaFork(str, options, dest, 156 needed_quoting); 157 #endif 158 break; 159 case ESCAPE_PLATFORM_WIN: 160 EscapeStringToString_WindowsNinjaFork(str, options, dest, 161 needed_quoting); 162 break; 163 case ESCAPE_PLATFORM_POSIX: 164 EscapeStringToString_PosixNinjaFork(str, options, dest, 165 needed_quoting); 166 break; 167 default: 168 NOTREACHED(); 169 } 170 break; 171 default: 172 NOTREACHED(); 173 } 174 } 175 176 } // namespace 177 178 std::string EscapeString(const base::StringPiece& str, 179 const EscapeOptions& options, 180 bool* needed_quoting) { 181 std::string result; 182 result.reserve(str.size() + 4); // Guess we'll add a couple of extra chars. 183 EscapeStringToString(str, options, &result, needed_quoting); 184 return result; 185 } 186 187 void EscapeStringToStream(std::ostream& out, 188 const base::StringPiece& str, 189 const EscapeOptions& options) { 190 base::StackString<256> escaped; 191 EscapeStringToString(str, options, &escaped.container(), NULL); 192 if (!escaped->empty()) 193 out.write(escaped->data(), escaped->size()); 194 } 195
