Ethan Nicholas | ca82a92 | 2017-09-07 09:39:50 -0400 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2017 Google Inc. |
| 3 | * |
| 4 | * Use of this source code is governed by a BSD-style license that can be |
| 5 | * found in the LICENSE file. |
| 6 | */ |
| 7 | |
Mike Klein | c0bd9f9 | 2019-04-23 12:05:21 -0500 | [diff] [blame] | 8 | #include "src/sksl/lex/NFAtoDFA.h" |
| 9 | #include "src/sksl/lex/RegexParser.h" |
Ethan Nicholas | ca82a92 | 2017-09-07 09:39:50 -0400 | [diff] [blame] | 10 | |
| 11 | #include <fstream> |
| 12 | #include <sstream> |
| 13 | #include <string> |
| 14 | |
| 15 | /** |
| 16 | * Processes a .lex file and produces .h and .cpp files which implement a lexical analyzer. The .lex |
| 17 | * file is a text file with one token definition per line. Each line is of the form: |
| 18 | * <TOKEN_NAME> = <pattern> |
| 19 | * where <pattern> is either a regular expression (e.g [0-9]) or a double-quoted literal string. |
| 20 | */ |
| 21 | |
| 22 | static constexpr const char* HEADER = |
| 23 | "/*\n" |
| 24 | " * Copyright 2017 Google Inc.\n" |
| 25 | " *\n" |
| 26 | " * Use of this source code is governed by a BSD-style license that can be\n" |
| 27 | " * found in the LICENSE file.\n" |
| 28 | " */\n" |
| 29 | "/*****************************************************************************************\n" |
| 30 | " ******************** This file was generated by sksllex. Do not edit. *******************\n" |
| 31 | " *****************************************************************************************/\n"; |
| 32 | |
| 33 | void writeH(const DFA& dfa, const char* lexer, const char* token, |
| 34 | const std::vector<std::string>& tokens, const char* hPath) { |
| 35 | std::ofstream out(hPath); |
Ethan Nicholas | d9d33c3 | 2018-06-12 11:05:59 -0400 | [diff] [blame] | 36 | SkASSERT(out.good()); |
Ethan Nicholas | ca82a92 | 2017-09-07 09:39:50 -0400 | [diff] [blame] | 37 | out << HEADER; |
| 38 | out << "#ifndef SKSL_" << lexer << "\n"; |
| 39 | out << "#define SKSL_" << lexer << "\n"; |
Ethan Nicholas | 6823b50 | 2021-06-15 11:42:07 -0400 | [diff] [blame] | 40 | out << "#include \"include/core/SkStringView.h\"\n"; |
Ethan Nicholas | ca82a92 | 2017-09-07 09:39:50 -0400 | [diff] [blame] | 41 | out << "#include <cstddef>\n"; |
| 42 | out << "#include <cstdint>\n"; |
| 43 | out << "namespace SkSL {\n"; |
| 44 | out << "\n"; |
| 45 | out << "struct " << token << " {\n"; |
Ethan Nicholas | 5a9e7fb | 2020-04-17 12:45:51 -0400 | [diff] [blame] | 46 | out << " enum class Kind {\n"; |
Ethan Nicholas | ca82a92 | 2017-09-07 09:39:50 -0400 | [diff] [blame] | 47 | for (const std::string& t : tokens) { |
Ethan Nicholas | 5a9e7fb | 2020-04-17 12:45:51 -0400 | [diff] [blame] | 48 | out << " TK_" << t << ",\n"; |
Ethan Nicholas | ca82a92 | 2017-09-07 09:39:50 -0400 | [diff] [blame] | 49 | } |
John Stiles | cc6961b | 2021-01-22 09:49:45 -0500 | [diff] [blame] | 50 | out << " TK_NONE,"; |
| 51 | out << R"( |
| 52 | }; |
| 53 | |
Ethan Nicholas | 5fad2b88 | 2021-09-27 10:39:18 -0400 | [diff] [blame^] | 54 | )" << token << "() {}"; |
John Stiles | cc6961b | 2021-01-22 09:49:45 -0500 | [diff] [blame] | 55 | |
Ethan Nicholas | 5fad2b88 | 2021-09-27 10:39:18 -0400 | [diff] [blame^] | 56 | out << token << R"((Kind kind, int32_t offset, int32_t length, int32_t line) |
John Stiles | cc6961b | 2021-01-22 09:49:45 -0500 | [diff] [blame] | 57 | : fKind(kind) |
| 58 | , fOffset(offset) |
Ethan Nicholas | 5fad2b88 | 2021-09-27 10:39:18 -0400 | [diff] [blame^] | 59 | , fLength(length) |
| 60 | , fLine(line) {} |
John Stiles | cc6961b | 2021-01-22 09:49:45 -0500 | [diff] [blame] | 61 | |
Ethan Nicholas | 5fad2b88 | 2021-09-27 10:39:18 -0400 | [diff] [blame^] | 62 | Kind fKind = Kind::TK_NONE; |
| 63 | int32_t fOffset = -1; |
| 64 | int32_t fLength = -1; |
| 65 | int32_t fLine = -1; |
John Stiles | cc6961b | 2021-01-22 09:49:45 -0500 | [diff] [blame] | 66 | }; |
| 67 | |
| 68 | class )" << lexer << R"( { |
| 69 | public: |
Ethan Nicholas | 6823b50 | 2021-06-15 11:42:07 -0400 | [diff] [blame] | 70 | void start(skstd::string_view text) { |
John Stiles | cc6961b | 2021-01-22 09:49:45 -0500 | [diff] [blame] | 71 | fText = text; |
John Stiles | cc6961b | 2021-01-22 09:49:45 -0500 | [diff] [blame] | 72 | fOffset = 0; |
Ethan Nicholas | 5fad2b88 | 2021-09-27 10:39:18 -0400 | [diff] [blame^] | 73 | fLine = 1; |
John Stiles | cc6961b | 2021-01-22 09:49:45 -0500 | [diff] [blame] | 74 | } |
| 75 | |
| 76 | )" << token << R"( next(); |
| 77 | |
Ethan Nicholas | 5fad2b88 | 2021-09-27 10:39:18 -0400 | [diff] [blame^] | 78 | struct Checkpoint { |
| 79 | int32_t fOffset; |
| 80 | int32_t fLine; |
| 81 | }; |
| 82 | |
| 83 | Checkpoint getCheckpoint() const { |
| 84 | return {fOffset, fLine}; |
John Stiles | cc6961b | 2021-01-22 09:49:45 -0500 | [diff] [blame] | 85 | } |
| 86 | |
Ethan Nicholas | 5fad2b88 | 2021-09-27 10:39:18 -0400 | [diff] [blame^] | 87 | void rewindToCheckpoint(Checkpoint checkpoint) { |
| 88 | fOffset = checkpoint.fOffset; |
| 89 | fLine = checkpoint.fLine; |
John Stiles | cc6961b | 2021-01-22 09:49:45 -0500 | [diff] [blame] | 90 | } |
| 91 | |
| 92 | private: |
Ethan Nicholas | 6823b50 | 2021-06-15 11:42:07 -0400 | [diff] [blame] | 93 | skstd::string_view fText; |
John Stiles | cc6961b | 2021-01-22 09:49:45 -0500 | [diff] [blame] | 94 | int32_t fOffset; |
Ethan Nicholas | 5fad2b88 | 2021-09-27 10:39:18 -0400 | [diff] [blame^] | 95 | int32_t fLine; |
John Stiles | cc6961b | 2021-01-22 09:49:45 -0500 | [diff] [blame] | 96 | }; |
| 97 | |
| 98 | } // namespace |
| 99 | #endif |
| 100 | )"; |
Ethan Nicholas | ca82a92 | 2017-09-07 09:39:50 -0400 | [diff] [blame] | 101 | } |
| 102 | |
| 103 | void writeCPP(const DFA& dfa, const char* lexer, const char* token, const char* include, |
| 104 | const char* cppPath) { |
| 105 | std::ofstream out(cppPath); |
Ethan Nicholas | d9d33c3 | 2018-06-12 11:05:59 -0400 | [diff] [blame] | 106 | SkASSERT(out.good()); |
Ethan Nicholas | ca82a92 | 2017-09-07 09:39:50 -0400 | [diff] [blame] | 107 | out << HEADER; |
| 108 | out << "#include \"" << include << "\"\n"; |
| 109 | out << "\n"; |
| 110 | out << "namespace SkSL {\n"; |
| 111 | out << "\n"; |
| 112 | |
| 113 | size_t states = 0; |
| 114 | for (const auto& row : dfa.fTransitions) { |
| 115 | states = std::max(states, row.size()); |
| 116 | } |
Brian Osman | bfcd782 | 2021-02-18 14:47:15 -0500 | [diff] [blame] | 117 | out << "using State = " << (states <= 256 ? "uint8_t" : "int16_t") << ";\n"; |
Ethan Nicholas | 10be9d5 | 2019-03-29 14:16:50 -0400 | [diff] [blame] | 118 | // arbitrarily-chosen character which is greater than START_CHAR and should not appear in actual |
| 119 | // input |
| 120 | out << "static const uint8_t INVALID_CHAR = 18;"; |
John Stiles | 31e4845 | 2021-09-13 13:47:04 -0400 | [diff] [blame] | 121 | out << "static const int8_t kMappings[" << dfa.fCharMappings.size() << "] = {\n "; |
Ethan Nicholas | 906126e | 2017-09-19 14:38:40 -0400 | [diff] [blame] | 122 | const char* separator = ""; |
| 123 | for (int m : dfa.fCharMappings) { |
| 124 | out << separator << std::to_string(m); |
| 125 | separator = ", "; |
| 126 | } |
| 127 | out << "\n};\n"; |
John Stiles | 31e4845 | 2021-09-13 13:47:04 -0400 | [diff] [blame] | 128 | out << "static const State kTransitions[" << dfa.fTransitions.size() << "][" |
| 129 | << states << "] = {\n"; |
Ethan Nicholas | 906126e | 2017-09-19 14:38:40 -0400 | [diff] [blame] | 130 | for (size_t c = 0; c < dfa.fTransitions.size(); ++c) { |
Ethan Nicholas | ca82a92 | 2017-09-07 09:39:50 -0400 | [diff] [blame] | 131 | out << " {"; |
Ethan Nicholas | 906126e | 2017-09-19 14:38:40 -0400 | [diff] [blame] | 132 | for (size_t j = 0; j < states; ++j) { |
| 133 | if ((size_t) c < dfa.fTransitions.size() && j < dfa.fTransitions[c].size()) { |
| 134 | out << " " << dfa.fTransitions[c][j] << ","; |
Ethan Nicholas | ca82a92 | 2017-09-07 09:39:50 -0400 | [diff] [blame] | 135 | } else { |
| 136 | out << " 0,"; |
| 137 | } |
| 138 | } |
| 139 | out << " },\n"; |
| 140 | } |
| 141 | out << "};\n"; |
| 142 | out << "\n"; |
| 143 | |
John Stiles | 31e4845 | 2021-09-13 13:47:04 -0400 | [diff] [blame] | 144 | out << "static const int8_t kAccepts[" << states << "] = {"; |
Ethan Nicholas | ca82a92 | 2017-09-07 09:39:50 -0400 | [diff] [blame] | 145 | for (size_t i = 0; i < states; ++i) { |
| 146 | if (i < dfa.fAccepts.size()) { |
| 147 | out << " " << dfa.fAccepts[i] << ","; |
| 148 | } else { |
Ethan Nicholas | 906126e | 2017-09-19 14:38:40 -0400 | [diff] [blame] | 149 | out << " " << INVALID << ","; |
Ethan Nicholas | ca82a92 | 2017-09-07 09:39:50 -0400 | [diff] [blame] | 150 | } |
| 151 | } |
| 152 | out << " };\n"; |
| 153 | out << "\n"; |
| 154 | |
John Stiles | cc6961b | 2021-01-22 09:49:45 -0500 | [diff] [blame] | 155 | out << token << " " << lexer << "::next() {"; |
| 156 | out << R"( |
| 157 | // note that we cheat here: normally a lexer needs to worry about the case |
| 158 | // where a token has a prefix which is not itself a valid token - for instance, |
| 159 | // maybe we have a valid token 'while', but 'w', 'wh', etc. are not valid |
| 160 | // tokens. Our grammar doesn't have this property, so we can simplify the logic |
| 161 | // a bit. |
| 162 | int32_t startOffset = fOffset; |
Ethan Nicholas | 6823b50 | 2021-06-15 11:42:07 -0400 | [diff] [blame] | 163 | if (startOffset == (int32_t)fText.length()) { |
Ethan Nicholas | 5fad2b88 | 2021-09-27 10:39:18 -0400 | [diff] [blame^] | 164 | return )" << token << "(" << token << R"(::Kind::TK_END_OF_FILE, startOffset, 0, fLine); |
John Stiles | cc6961b | 2021-01-22 09:49:45 -0500 | [diff] [blame] | 165 | } |
Brian Osman | bfcd782 | 2021-02-18 14:47:15 -0500 | [diff] [blame] | 166 | State state = 1; |
John Stiles | cc6961b | 2021-01-22 09:49:45 -0500 | [diff] [blame] | 167 | for (;;) { |
Ethan Nicholas | 6823b50 | 2021-06-15 11:42:07 -0400 | [diff] [blame] | 168 | if (fOffset >= (int32_t)fText.length()) { |
John Stiles | 31e4845 | 2021-09-13 13:47:04 -0400 | [diff] [blame] | 169 | if (kAccepts[state] == -1) { |
Ethan Nicholas | 5fad2b88 | 2021-09-27 10:39:18 -0400 | [diff] [blame^] | 170 | return Token(Token::Kind::TK_END_OF_FILE, startOffset, 0, fLine); |
John Stiles | cc6961b | 2021-01-22 09:49:45 -0500 | [diff] [blame] | 171 | } |
| 172 | break; |
| 173 | } |
| 174 | uint8_t c = (uint8_t) fText[fOffset]; |
| 175 | if (c <= 8 || c >= )" << dfa.fCharMappings.size() << R"() { |
| 176 | c = INVALID_CHAR; |
| 177 | } |
John Stiles | 31e4845 | 2021-09-13 13:47:04 -0400 | [diff] [blame] | 178 | State newState = kTransitions[kMappings[c]][state]; |
John Stiles | cc6961b | 2021-01-22 09:49:45 -0500 | [diff] [blame] | 179 | if (!newState) { |
| 180 | break; |
| 181 | } |
| 182 | state = newState; |
| 183 | ++fOffset; |
Ethan Nicholas | 5fad2b88 | 2021-09-27 10:39:18 -0400 | [diff] [blame^] | 184 | if (c == '\n') { |
| 185 | ++fLine; |
| 186 | } |
John Stiles | cc6961b | 2021-01-22 09:49:45 -0500 | [diff] [blame] | 187 | } |
John Stiles | 31e4845 | 2021-09-13 13:47:04 -0400 | [diff] [blame] | 188 | Token::Kind kind = ()" << token << R"(::Kind) kAccepts[state]; |
Ethan Nicholas | 5fad2b88 | 2021-09-27 10:39:18 -0400 | [diff] [blame^] | 189 | return )" << token << R"((kind, startOffset, fOffset - startOffset, fLine); |
John Stiles | cc6961b | 2021-01-22 09:49:45 -0500 | [diff] [blame] | 190 | } |
| 191 | |
| 192 | } // namespace |
| 193 | )"; |
Ethan Nicholas | ca82a92 | 2017-09-07 09:39:50 -0400 | [diff] [blame] | 194 | } |
| 195 | |
| 196 | void process(const char* inPath, const char* lexer, const char* token, const char* hPath, |
| 197 | const char* cppPath) { |
| 198 | NFA nfa; |
| 199 | std::vector<std::string> tokens; |
| 200 | tokens.push_back("END_OF_FILE"); |
| 201 | std::string line; |
| 202 | std::ifstream in(inPath); |
| 203 | while (std::getline(in, line)) { |
Ethan Nicholas | f3c8f5d | 2020-08-20 13:09:14 +0000 | [diff] [blame] | 204 | if (line.length() == 0) { |
| 205 | continue; |
| 206 | } |
| 207 | if (line.length() >= 2 && line[0] == '/' && line[1] == '/') { |
| 208 | continue; |
| 209 | } |
Ethan Nicholas | ca82a92 | 2017-09-07 09:39:50 -0400 | [diff] [blame] | 210 | std::istringstream split(line); |
| 211 | std::string name, delimiter, pattern; |
| 212 | if (split >> name >> delimiter >> pattern) { |
Ethan Nicholas | d9d33c3 | 2018-06-12 11:05:59 -0400 | [diff] [blame] | 213 | SkASSERT(split.eof()); |
| 214 | SkASSERT(name != ""); |
| 215 | SkASSERT(delimiter == "="); |
| 216 | SkASSERT(pattern != ""); |
Ethan Nicholas | ca82a92 | 2017-09-07 09:39:50 -0400 | [diff] [blame] | 217 | tokens.push_back(name); |
| 218 | if (pattern[0] == '"') { |
Ethan Nicholas | d9d33c3 | 2018-06-12 11:05:59 -0400 | [diff] [blame] | 219 | SkASSERT(pattern.size() > 2 && pattern[pattern.size() - 1] == '"'); |
Ethan Nicholas | ca82a92 | 2017-09-07 09:39:50 -0400 | [diff] [blame] | 220 | RegexNode node = RegexNode(RegexNode::kChar_Kind, pattern[1]); |
| 221 | for (size_t i = 2; i < pattern.size() - 1; ++i) { |
| 222 | node = RegexNode(RegexNode::kConcat_Kind, node, |
| 223 | RegexNode(RegexNode::kChar_Kind, pattern[i])); |
| 224 | } |
| 225 | nfa.addRegex(node); |
| 226 | } |
| 227 | else { |
| 228 | nfa.addRegex(RegexParser().parse(pattern)); |
| 229 | } |
| 230 | } |
| 231 | } |
| 232 | NFAtoDFA converter(&nfa); |
| 233 | DFA dfa = converter.convert(); |
| 234 | writeH(dfa, lexer, token, tokens, hPath); |
Mike Klein | c0bd9f9 | 2019-04-23 12:05:21 -0500 | [diff] [blame] | 235 | writeCPP(dfa, lexer, token, (std::string("src/sksl/SkSL") + lexer + ".h").c_str(), cppPath); |
Ethan Nicholas | ca82a92 | 2017-09-07 09:39:50 -0400 | [diff] [blame] | 236 | } |
| 237 | |
| 238 | int main(int argc, const char** argv) { |
| 239 | if (argc != 6) { |
| 240 | printf("usage: sksllex <input.lex> <lexername> <tokenname> <output.h> <output.cpp>\n"); |
| 241 | exit(1); |
| 242 | } |
| 243 | process(argv[1], argv[2], argv[3], argv[4], argv[5]); |
| 244 | return 0; |
| 245 | } |