1 //===-- ClangExpressionSourceCode.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 "ClangExpressionSourceCode.h" 10 11 #include "clang/Basic/CharInfo.h" 12 #include "clang/Basic/FileManager.h" 13 #include "clang/Basic/SourceManager.h" 14 #include "clang/Lex/Lexer.h" 15 #include "llvm/ADT/StringRef.h" 16 17 #include "Plugins/ExpressionParser/Clang/ClangModulesDeclVendor.h" 18 #include "Plugins/ExpressionParser/Clang/ClangPersistentVariables.h" 19 #include "lldb/Symbol/Block.h" 20 #include "lldb/Symbol/CompileUnit.h" 21 #include "lldb/Symbol/DebugMacros.h" 22 #include "lldb/Symbol/TypeSystem.h" 23 #include "lldb/Symbol/VariableList.h" 24 #include "lldb/Target/ExecutionContext.h" 25 #include "lldb/Target/Language.h" 26 #include "lldb/Target/Platform.h" 27 #include "lldb/Target/StackFrame.h" 28 #include "lldb/Target/Target.h" 29 #include "lldb/Utility/StreamString.h" 30 31 using namespace lldb_private; 32 33 #define PREFIX_NAME "<lldb wrapper prefix>" 34 35 const llvm::StringRef ClangExpressionSourceCode::g_prefix_file_name = PREFIX_NAME; 36 37 const char *ClangExpressionSourceCode::g_expression_prefix = 38 "#line 1 \"" PREFIX_NAME R"(" 39 #ifndef offsetof 40 #define offsetof(t, d) __builtin_offsetof(t, d) 41 #endif 42 #ifndef NULL 43 #define NULL (__null) 44 #endif 45 #ifndef Nil 46 #define Nil (__null) 47 #endif 48 #ifndef nil 49 #define nil (__null) 50 #endif 51 #ifndef YES 52 #define YES ((BOOL)1) 53 #endif 54 #ifndef NO 55 #define NO ((BOOL)0) 56 #endif 57 typedef __INT8_TYPE__ int8_t; 58 typedef __UINT8_TYPE__ uint8_t; 59 typedef __INT16_TYPE__ int16_t; 60 typedef __UINT16_TYPE__ uint16_t; 61 typedef __INT32_TYPE__ int32_t; 62 typedef __UINT32_TYPE__ uint32_t; 63 typedef __INT64_TYPE__ int64_t; 64 typedef __UINT64_TYPE__ uint64_t; 65 typedef __INTPTR_TYPE__ intptr_t; 66 typedef __UINTPTR_TYPE__ uintptr_t; 67 typedef __SIZE_TYPE__ size_t; 68 typedef __PTRDIFF_TYPE__ ptrdiff_t; 69 typedef unsigned short unichar; 70 extern "C" 71 { 72 int printf(const char * __restrict, ...); 73 } 74 )"; 75 76 namespace { 77 78 class AddMacroState { 79 enum State { 80 CURRENT_FILE_NOT_YET_PUSHED, 81 CURRENT_FILE_PUSHED, 82 CURRENT_FILE_POPPED 83 }; 84 85 public: 86 AddMacroState(const FileSpec ¤t_file, const uint32_t current_file_line) 87 : m_state(CURRENT_FILE_NOT_YET_PUSHED), m_current_file(current_file), 88 m_current_file_line(current_file_line) {} 89 90 void StartFile(const FileSpec &file) { 91 m_file_stack.push_back(file); 92 if (file == m_current_file) 93 m_state = CURRENT_FILE_PUSHED; 94 } 95 96 void EndFile() { 97 if (m_file_stack.size() == 0) 98 return; 99 100 FileSpec old_top = m_file_stack.back(); 101 m_file_stack.pop_back(); 102 if (old_top == m_current_file) 103 m_state = CURRENT_FILE_POPPED; 104 } 105 106 // An entry is valid if it occurs before the current line in the current 107 // file. 108 bool IsValidEntry(uint32_t line) { 109 switch (m_state) { 110 case CURRENT_FILE_NOT_YET_PUSHED: 111 return true; 112 case CURRENT_FILE_PUSHED: 113 // If we are in file included in the current file, the entry should be 114 // added. 115 if (m_file_stack.back() != m_current_file) 116 return true; 117 118 return line < m_current_file_line; 119 default: 120 return false; 121 } 122 } 123 124 private: 125 std::vector<FileSpec> m_file_stack; 126 State m_state; 127 FileSpec m_current_file; 128 uint32_t m_current_file_line; 129 }; 130 131 } // anonymous namespace 132 133 static void AddMacros(const DebugMacros *dm, CompileUnit *comp_unit, 134 AddMacroState &state, StreamString &stream) { 135 if (dm == nullptr) 136 return; 137 138 for (size_t i = 0; i < dm->GetNumMacroEntries(); i++) { 139 const DebugMacroEntry &entry = dm->GetMacroEntryAtIndex(i); 140 uint32_t line; 141 142 switch (entry.GetType()) { 143 case DebugMacroEntry::DEFINE: 144 if (state.IsValidEntry(entry.GetLineNumber())) 145 stream.Printf("#define %s\n", entry.GetMacroString().AsCString()); 146 else 147 return; 148 break; 149 case DebugMacroEntry::UNDEF: 150 if (state.IsValidEntry(entry.GetLineNumber())) 151 stream.Printf("#undef %s\n", entry.GetMacroString().AsCString()); 152 else 153 return; 154 break; 155 case DebugMacroEntry::START_FILE: 156 line = entry.GetLineNumber(); 157 if (state.IsValidEntry(line)) 158 state.StartFile(entry.GetFileSpec(comp_unit)); 159 else 160 return; 161 break; 162 case DebugMacroEntry::END_FILE: 163 state.EndFile(); 164 break; 165 case DebugMacroEntry::INDIRECT: 166 AddMacros(entry.GetIndirectDebugMacros(), comp_unit, state, stream); 167 break; 168 default: 169 // This is an unknown/invalid entry. Ignore. 170 break; 171 } 172 } 173 } 174 175 lldb_private::ClangExpressionSourceCode::ClangExpressionSourceCode( 176 llvm::StringRef filename, llvm::StringRef name, llvm::StringRef prefix, 177 llvm::StringRef body, Wrapping wrap, WrapKind wrap_kind) 178 : ExpressionSourceCode(name, prefix, body, wrap), m_wrap_kind(wrap_kind) { 179 // Use #line markers to pretend that we have a single-line source file 180 // containing only the user expression. This will hide our wrapper code 181 // from the user when we render diagnostics with Clang. 182 m_start_marker = "#line 1 \"" + filename.str() + "\"\n"; 183 m_end_marker = "\n;\n#line 1 \"<lldb wrapper suffix>\"\n"; 184 } 185 186 namespace { 187 /// Allows checking if a token is contained in a given expression. 188 class TokenVerifier { 189 /// The tokens we found in the expression. 190 llvm::StringSet<> m_tokens; 191 192 public: 193 TokenVerifier(std::string body); 194 /// Returns true iff the given expression body contained a token with the 195 /// given content. 196 bool hasToken(llvm::StringRef token) const { 197 return m_tokens.find(token) != m_tokens.end(); 198 } 199 }; 200 } // namespace 201 202 TokenVerifier::TokenVerifier(std::string body) { 203 using namespace clang; 204 205 // We only care about tokens and not their original source locations. If we 206 // move the whole expression to only be in one line we can simplify the 207 // following code that extracts the token contents. 208 std::replace(body.begin(), body.end(), '\n', ' '); 209 std::replace(body.begin(), body.end(), '\r', ' '); 210 211 FileSystemOptions file_opts; 212 FileManager file_mgr(file_opts, 213 FileSystem::Instance().GetVirtualFileSystem()); 214 215 // Let's build the actual source code Clang needs and setup some utility 216 // objects. 217 llvm::IntrusiveRefCntPtr<DiagnosticIDs> diag_ids(new DiagnosticIDs()); 218 llvm::IntrusiveRefCntPtr<DiagnosticOptions> diags_opts( 219 new DiagnosticOptions()); 220 DiagnosticsEngine diags(diag_ids, diags_opts); 221 clang::SourceManager SM(diags, file_mgr); 222 auto buf = llvm::MemoryBuffer::getMemBuffer(body); 223 224 FileID FID = SM.createFileID(buf->getMemBufferRef()); 225 226 // Let's just enable the latest ObjC and C++ which should get most tokens 227 // right. 228 LangOptions Opts; 229 Opts.ObjC = true; 230 Opts.DollarIdents = true; 231 Opts.CPlusPlus17 = true; 232 Opts.LineComment = true; 233 234 Lexer lex(FID, buf->getMemBufferRef(), SM, Opts); 235 236 Token token; 237 bool exit = false; 238 while (!exit) { 239 // Returns true if this is the last token we get from the lexer. 240 exit = lex.LexFromRawLexer(token); 241 242 // Extract the column number which we need to extract the token content. 243 // Our expression is just one line, so we don't need to handle any line 244 // numbers here. 245 bool invalid = false; 246 unsigned start = SM.getSpellingColumnNumber(token.getLocation(), &invalid); 247 if (invalid) 248 continue; 249 // Column numbers start at 1, but indexes in our string start at 0. 250 --start; 251 252 // Annotations don't have a length, so let's skip them. 253 if (token.isAnnotation()) 254 continue; 255 256 // Extract the token string from our source code and store it. 257 std::string token_str = body.substr(start, token.getLength()); 258 if (token_str.empty()) 259 continue; 260 m_tokens.insert(token_str); 261 } 262 } 263 264 void ClangExpressionSourceCode::AddLocalVariableDecls( 265 const lldb::VariableListSP &var_list_sp, StreamString &stream, 266 const std::string &expr) const { 267 TokenVerifier tokens(expr); 268 269 for (size_t i = 0; i < var_list_sp->GetSize(); i++) { 270 lldb::VariableSP var_sp = var_list_sp->GetVariableAtIndex(i); 271 272 ConstString var_name = var_sp->GetName(); 273 274 275 // We can check for .block_descriptor w/o checking for langauge since this 276 // is not a valid identifier in either C or C++. 277 if (!var_name || var_name == ".block_descriptor") 278 continue; 279 280 if (!expr.empty() && !tokens.hasToken(var_name.GetStringRef())) 281 continue; 282 283 const bool is_objc = m_wrap_kind == WrapKind::ObjCInstanceMethod || 284 m_wrap_kind == WrapKind::ObjCStaticMethod; 285 if ((var_name == "self" || var_name == "_cmd") && is_objc) 286 continue; 287 288 if (var_name == "this" && m_wrap_kind == WrapKind::CppMemberFunction) 289 continue; 290 291 stream.Printf("using $__lldb_local_vars::%s;\n", var_name.AsCString()); 292 } 293 } 294 295 bool ClangExpressionSourceCode::GetText( 296 std::string &text, ExecutionContext &exe_ctx, bool add_locals, 297 bool force_add_all_locals, llvm::ArrayRef<std::string> modules) const { 298 const char *target_specific_defines = "typedef signed char BOOL;\n"; 299 std::string module_macros; 300 llvm::raw_string_ostream module_macros_stream(module_macros); 301 302 Target *target = exe_ctx.GetTargetPtr(); 303 if (target) { 304 if (target->GetArchitecture().GetMachine() == llvm::Triple::aarch64 || 305 target->GetArchitecture().GetMachine() == llvm::Triple::aarch64_32) { 306 target_specific_defines = "typedef bool BOOL;\n"; 307 } 308 if (target->GetArchitecture().GetMachine() == llvm::Triple::x86_64) { 309 if (lldb::PlatformSP platform_sp = target->GetPlatform()) { 310 static ConstString g_platform_ios_simulator("ios-simulator"); 311 if (platform_sp->GetPluginName() == g_platform_ios_simulator) { 312 target_specific_defines = "typedef bool BOOL;\n"; 313 } 314 } 315 } 316 317 ClangModulesDeclVendor *decl_vendor = target->GetClangModulesDeclVendor(); 318 auto *persistent_vars = llvm::cast<ClangPersistentVariables>( 319 target->GetPersistentExpressionStateForLanguage(lldb::eLanguageTypeC)); 320 if (decl_vendor && persistent_vars) { 321 const ClangModulesDeclVendor::ModuleVector &hand_imported_modules = 322 persistent_vars->GetHandLoadedClangModules(); 323 ClangModulesDeclVendor::ModuleVector modules_for_macros; 324 325 for (ClangModulesDeclVendor::ModuleID module : hand_imported_modules) { 326 modules_for_macros.push_back(module); 327 } 328 329 if (target->GetEnableAutoImportClangModules()) { 330 if (StackFrame *frame = exe_ctx.GetFramePtr()) { 331 if (Block *block = frame->GetFrameBlock()) { 332 SymbolContext sc; 333 334 block->CalculateSymbolContext(&sc); 335 336 if (sc.comp_unit) { 337 StreamString error_stream; 338 339 decl_vendor->AddModulesForCompileUnit( 340 *sc.comp_unit, modules_for_macros, error_stream); 341 } 342 } 343 } 344 } 345 346 decl_vendor->ForEachMacro( 347 modules_for_macros, 348 [&module_macros_stream](llvm::StringRef token, 349 llvm::StringRef expansion) -> bool { 350 // Check if the macro hasn't already been defined in the 351 // g_expression_prefix (which defines a few builtin macros). 352 module_macros_stream << "#ifndef " << token << "\n"; 353 module_macros_stream << expansion << "\n"; 354 module_macros_stream << "#endif\n"; 355 return false; 356 }); 357 } 358 } 359 360 StreamString debug_macros_stream; 361 StreamString lldb_local_var_decls; 362 if (StackFrame *frame = exe_ctx.GetFramePtr()) { 363 const SymbolContext &sc = frame->GetSymbolContext( 364 lldb::eSymbolContextCompUnit | lldb::eSymbolContextLineEntry); 365 366 if (sc.comp_unit && sc.line_entry.IsValid()) { 367 DebugMacros *dm = sc.comp_unit->GetDebugMacros(); 368 if (dm) { 369 AddMacroState state(sc.line_entry.file, sc.line_entry.line); 370 AddMacros(dm, sc.comp_unit, state, debug_macros_stream); 371 } 372 } 373 374 if (add_locals) 375 if (target->GetInjectLocalVariables(&exe_ctx)) { 376 lldb::VariableListSP var_list_sp = 377 frame->GetInScopeVariableList(false, true); 378 AddLocalVariableDecls(var_list_sp, lldb_local_var_decls, 379 force_add_all_locals ? "" : m_body); 380 } 381 } 382 383 if (m_wrap) { 384 // Generate a list of @import statements that will import the specified 385 // module into our expression. 386 std::string module_imports; 387 for (const std::string &module : modules) { 388 module_imports.append("@import "); 389 module_imports.append(module); 390 module_imports.append(";\n"); 391 } 392 393 StreamString wrap_stream; 394 395 wrap_stream.Printf("%s\n%s\n%s\n%s\n%s\n", g_expression_prefix, 396 module_macros.c_str(), debug_macros_stream.GetData(), 397 target_specific_defines, m_prefix.c_str()); 398 399 // First construct a tagged form of the user expression so we can find it 400 // later: 401 std::string tagged_body; 402 tagged_body.append(m_start_marker); 403 tagged_body.append(m_body); 404 tagged_body.append(m_end_marker); 405 406 switch (m_wrap_kind) { 407 case WrapKind::Function: 408 wrap_stream.Printf("%s" 409 "void \n" 410 "%s(void *$__lldb_arg) \n" 411 "{ \n" 412 " %s; \n" 413 "%s" 414 "} \n", 415 module_imports.c_str(), m_name.c_str(), 416 lldb_local_var_decls.GetData(), tagged_body.c_str()); 417 break; 418 case WrapKind::CppMemberFunction: 419 wrap_stream.Printf("%s" 420 "void \n" 421 "$__lldb_class::%s(void *$__lldb_arg) \n" 422 "{ \n" 423 " %s; \n" 424 "%s" 425 "} \n", 426 module_imports.c_str(), m_name.c_str(), 427 lldb_local_var_decls.GetData(), tagged_body.c_str()); 428 break; 429 case WrapKind::ObjCInstanceMethod: 430 wrap_stream.Printf( 431 "%s" 432 "@interface $__lldb_objc_class ($__lldb_category) \n" 433 "-(void)%s:(void *)$__lldb_arg; \n" 434 "@end \n" 435 "@implementation $__lldb_objc_class ($__lldb_category) \n" 436 "-(void)%s:(void *)$__lldb_arg \n" 437 "{ \n" 438 " %s; \n" 439 "%s" 440 "} \n" 441 "@end \n", 442 module_imports.c_str(), m_name.c_str(), m_name.c_str(), 443 lldb_local_var_decls.GetData(), tagged_body.c_str()); 444 break; 445 446 case WrapKind::ObjCStaticMethod: 447 wrap_stream.Printf( 448 "%s" 449 "@interface $__lldb_objc_class ($__lldb_category) \n" 450 "+(void)%s:(void *)$__lldb_arg; \n" 451 "@end \n" 452 "@implementation $__lldb_objc_class ($__lldb_category) \n" 453 "+(void)%s:(void *)$__lldb_arg \n" 454 "{ \n" 455 " %s; \n" 456 "%s" 457 "} \n" 458 "@end \n", 459 module_imports.c_str(), m_name.c_str(), m_name.c_str(), 460 lldb_local_var_decls.GetData(), tagged_body.c_str()); 461 break; 462 } 463 464 text = std::string(wrap_stream.GetString()); 465 } else { 466 text.append(m_body); 467 } 468 469 return true; 470 } 471 472 bool ClangExpressionSourceCode::GetOriginalBodyBounds( 473 std::string transformed_text, size_t &start_loc, size_t &end_loc) { 474 start_loc = transformed_text.find(m_start_marker); 475 if (start_loc == std::string::npos) 476 return false; 477 start_loc += m_start_marker.size(); 478 end_loc = transformed_text.find(m_end_marker); 479 return end_loc != std::string::npos; 480 } 481