1 //===-- ClangHighlighter.cpp ----------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "ClangHighlighter.h" 10 11 #include "lldb/Host/FileSystem.h" 12 #include "lldb/Target/Language.h" 13 #include "lldb/Utility/AnsiTerminal.h" 14 #include "lldb/Utility/StreamString.h" 15 16 #include "clang/Basic/FileManager.h" 17 #include "clang/Basic/SourceManager.h" 18 #include "clang/Lex/Lexer.h" 19 #include "llvm/ADT/StringSet.h" 20 #include "llvm/Support/MemoryBuffer.h" 21 22 using namespace lldb_private; 23 24 bool ClangHighlighter::isKeyword(llvm::StringRef token) const { 25 return keywords.find(token) != keywords.end(); 26 } 27 28 ClangHighlighter::ClangHighlighter() { 29 #define KEYWORD(X, N) keywords.insert(#X); 30 #include "clang/Basic/TokenKinds.def" 31 } 32 33 /// Determines which style should be applied to the given token. 34 /// \param highlighter 35 /// The current highlighter that should use the style. 36 /// \param token 37 /// The current token. 38 /// \param tok_str 39 /// The string in the source code the token represents. 40 /// \param options 41 /// The style we use for coloring the source code. 42 /// \param in_pp_directive 43 /// If we are currently in a preprocessor directive. NOTE: This is 44 /// passed by reference and will be updated if the current token starts 45 /// or ends a preprocessor directive. 46 /// \return 47 /// The ColorStyle that should be applied to the token. 48 static HighlightStyle::ColorStyle 49 determineClangStyle(const ClangHighlighter &highlighter, 50 const clang::Token &token, llvm::StringRef tok_str, 51 const HighlightStyle &options, bool &in_pp_directive) { 52 using namespace clang; 53 54 if (token.is(tok::comment)) { 55 // If we were in a preprocessor directive before, we now left it. 56 in_pp_directive = false; 57 return options.comment; 58 } else if (in_pp_directive || token.getKind() == tok::hash) { 59 // Let's assume that the rest of the line is a PP directive. 60 in_pp_directive = true; 61 // Preprocessor directives are hard to match, so we have to hack this in. 62 return options.pp_directive; 63 } else if (tok::isStringLiteral(token.getKind())) 64 return options.string_literal; 65 else if (tok::isLiteral(token.getKind())) 66 return options.scalar_literal; 67 else if (highlighter.isKeyword(tok_str)) 68 return options.keyword; 69 else 70 switch (token.getKind()) { 71 case tok::raw_identifier: 72 case tok::identifier: 73 return options.identifier; 74 case tok::l_brace: 75 case tok::r_brace: 76 return options.braces; 77 case tok::l_square: 78 case tok::r_square: 79 return options.square_brackets; 80 case tok::l_paren: 81 case tok::r_paren: 82 return options.parentheses; 83 case tok::comma: 84 return options.comma; 85 case tok::coloncolon: 86 case tok::colon: 87 return options.colon; 88 89 case tok::amp: 90 case tok::ampamp: 91 case tok::ampequal: 92 case tok::star: 93 case tok::starequal: 94 case tok::plus: 95 case tok::plusplus: 96 case tok::plusequal: 97 case tok::minus: 98 case tok::arrow: 99 case tok::minusminus: 100 case tok::minusequal: 101 case tok::tilde: 102 case tok::exclaim: 103 case tok::exclaimequal: 104 case tok::slash: 105 case tok::slashequal: 106 case tok::percent: 107 case tok::percentequal: 108 case tok::less: 109 case tok::lessless: 110 case tok::lessequal: 111 case tok::lesslessequal: 112 case tok::spaceship: 113 case tok::greater: 114 case tok::greatergreater: 115 case tok::greaterequal: 116 case tok::greatergreaterequal: 117 case tok::caret: 118 case tok::caretequal: 119 case tok::pipe: 120 case tok::pipepipe: 121 case tok::pipeequal: 122 case tok::question: 123 case tok::equal: 124 case tok::equalequal: 125 return options.operators; 126 default: 127 break; 128 } 129 return HighlightStyle::ColorStyle(); 130 } 131 132 void ClangHighlighter::Highlight(const HighlightStyle &options, 133 llvm::StringRef line, 134 llvm::Optional<size_t> cursor_pos, 135 llvm::StringRef previous_lines, 136 Stream &result) const { 137 using namespace clang; 138 139 FileSystemOptions file_opts; 140 FileManager file_mgr(file_opts, 141 FileSystem::Instance().GetVirtualFileSystem()); 142 143 // The line might end in a backslash which would cause Clang to drop the 144 // backslash and the terminating new line. This makes sense when parsing C++, 145 // but when highlighting we care about preserving the backslash/newline. To 146 // not lose this information we remove the new line here so that Clang knows 147 // this is just a single line we are highlighting. We add back the newline 148 // after tokenizing. 149 llvm::StringRef line_ending = ""; 150 // There are a few legal line endings Clang recognizes and we need to 151 // temporarily remove from the string. 152 if (line.consume_back("\r\n")) 153 line_ending = "\r\n"; 154 else if (line.consume_back("\n")) 155 line_ending = "\n"; 156 else if (line.consume_back("\r")) 157 line_ending = "\r"; 158 159 unsigned line_number = previous_lines.count('\n') + 1U; 160 161 // Let's build the actual source code Clang needs and setup some utility 162 // objects. 163 std::string full_source = previous_lines.str() + line.str(); 164 llvm::IntrusiveRefCntPtr<DiagnosticIDs> diag_ids(new DiagnosticIDs()); 165 llvm::IntrusiveRefCntPtr<DiagnosticOptions> diags_opts( 166 new DiagnosticOptions()); 167 DiagnosticsEngine diags(diag_ids, diags_opts); 168 clang::SourceManager SM(diags, file_mgr); 169 auto buf = llvm::MemoryBuffer::getMemBuffer(full_source); 170 171 FileID FID = SM.createFileID(buf->getMemBufferRef()); 172 173 // Let's just enable the latest ObjC and C++ which should get most tokens 174 // right. 175 LangOptions Opts; 176 Opts.ObjC = true; 177 // FIXME: This should probably set CPlusPlus, CPlusPlus11, ... too 178 Opts.CPlusPlus17 = true; 179 Opts.LineComment = true; 180 181 Lexer lex(FID, buf->getMemBufferRef(), SM, Opts); 182 // The lexer should keep whitespace around. 183 lex.SetKeepWhitespaceMode(true); 184 185 // Keeps track if we have entered a PP directive. 186 bool in_pp_directive = false; 187 188 // True once we actually lexed the user provided line. 189 bool found_user_line = false; 190 191 // True if we already highlighted the token under the cursor, false otherwise. 192 bool highlighted_cursor = false; 193 Token token; 194 bool exit = false; 195 while (!exit) { 196 // Returns true if this is the last token we get from the lexer. 197 exit = lex.LexFromRawLexer(token); 198 199 bool invalid = false; 200 unsigned current_line_number = 201 SM.getSpellingLineNumber(token.getLocation(), &invalid); 202 if (current_line_number != line_number) 203 continue; 204 found_user_line = true; 205 206 // We don't need to print any tokens without a spelling line number. 207 if (invalid) 208 continue; 209 210 // Same as above but with the column number. 211 invalid = false; 212 unsigned start = SM.getSpellingColumnNumber(token.getLocation(), &invalid); 213 if (invalid) 214 continue; 215 // Column numbers start at 1, but indexes in our string start at 0. 216 --start; 217 218 // Annotations don't have a length, so let's skip them. 219 if (token.isAnnotation()) 220 continue; 221 222 // Extract the token string from our source code. 223 llvm::StringRef tok_str = line.substr(start, token.getLength()); 224 225 // If the token is just an empty string, we can skip all the work below. 226 if (tok_str.empty()) 227 continue; 228 229 // If the cursor is inside this token, we have to apply the 'selected' 230 // highlight style before applying the actual token color. 231 llvm::StringRef to_print = tok_str; 232 StreamString storage; 233 auto end = start + token.getLength(); 234 if (cursor_pos && end > *cursor_pos && !highlighted_cursor) { 235 highlighted_cursor = true; 236 options.selected.Apply(storage, tok_str); 237 to_print = storage.GetString(); 238 } 239 240 // See how we are supposed to highlight this token. 241 HighlightStyle::ColorStyle color = 242 determineClangStyle(*this, token, tok_str, options, in_pp_directive); 243 244 color.Apply(result, to_print); 245 } 246 247 // Add the line ending we trimmed before tokenizing. 248 result << line_ending; 249 250 // If we went over the whole file but couldn't find our own file, then 251 // somehow our setup was wrong. When we're in release mode we just give the 252 // user the normal line and pretend we don't know how to highlight it. In 253 // debug mode we bail out with an assert as this should never happen. 254 if (!found_user_line) { 255 result << line; 256 assert(false && "We couldn't find the user line in the input file?"); 257 } 258 } 259