1 //===-- ClangExpressionDeclMap.h --------------------------------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef liblldb_ClangExpressionDeclMap_h_ 11 #define liblldb_ClangExpressionDeclMap_h_ 12 13 // C Includes 14 #include <signal.h> 15 #include <stdint.h> 16 17 // C++ Includes 18 #include <vector> 19 20 // Other libraries and framework includes 21 // Project includes 22 #include "llvm/ADT/APInt.h" 23 #include "llvm/ADT/DenseMap.h" 24 #include "clang/AST/Decl.h" 25 #include "lldb/lldb-public.h" 26 #include "lldb/Core/ClangForward.h" 27 #include "lldb/Core/Value.h" 28 #include "lldb/Expression/ClangASTSource.h" 29 #include "lldb/Expression/ClangExpressionVariable.h" 30 #include "lldb/Expression/Materializer.h" 31 #include "lldb/Symbol/TaggedASTType.h" 32 #include "lldb/Symbol/SymbolContext.h" 33 #include "lldb/Target/ExecutionContext.h" 34 35 namespace lldb_private { 36 37 //---------------------------------------------------------------------- 38 /// @class ClangExpressionDeclMap ClangExpressionDeclMap.h "lldb/Expression/ClangExpressionDeclMap.h" 39 /// @brief Manages named entities that are defined in LLDB's debug information. 40 /// 41 /// The Clang parser uses the ClangASTSource as an interface to request named 42 /// entities from outside an expression. The ClangASTSource reports back, listing 43 /// all possible objects corresponding to a particular name. But it in turn 44 /// relies on ClangExpressionDeclMap, which performs several important functions. 45 /// 46 /// First, it records what variables and functions were looked up and what Decls 47 /// were returned for them. 48 /// 49 /// Second, it constructs a struct on behalf of IRForTarget, recording which 50 /// variables should be placed where and relaying this information back so that 51 /// IRForTarget can generate context-independent code. 52 /// 53 /// Third, it "materializes" this struct on behalf of the expression command, 54 /// finding the current values of each variable and placing them into the 55 /// struct so that it can be passed to the JITted version of the IR. 56 /// 57 /// Fourth and finally, it "dematerializes" the struct after the JITted code has 58 /// has executed, placing the new values back where it found the old ones. 59 //---------------------------------------------------------------------- 60 class ClangExpressionDeclMap : 61 public ClangASTSource 62 { 63 public: 64 //------------------------------------------------------------------ 65 /// Constructor 66 /// 67 /// Initializes class variables. 68 /// 69 /// @param[in] keep_result_in_memory 70 /// If true, inhibits the normal deallocation of the memory for 71 /// the result persistent variable, and instead marks the variable 72 /// as persisting. 73 /// 74 /// @param[in] exe_ctx 75 /// The execution context to use when parsing. 76 //------------------------------------------------------------------ 77 ClangExpressionDeclMap (bool keep_result_in_memory, 78 ExecutionContext &exe_ctx); 79 80 //------------------------------------------------------------------ 81 /// Destructor 82 //------------------------------------------------------------------ 83 ~ClangExpressionDeclMap (); 84 85 //------------------------------------------------------------------ 86 /// Enable the state needed for parsing and IR transformation. 87 /// 88 /// @param[in] exe_ctx 89 /// The execution context to use when finding types for variables. 90 /// Also used to find a "scratch" AST context to store result types. 91 /// 92 /// @param[in] materializer 93 /// If non-NULL, the materializer to populate with information about 94 /// the variables to use 95 /// 96 /// @return 97 /// True if parsing is possible; false if it is unsafe to continue. 98 //------------------------------------------------------------------ 99 bool 100 WillParse (ExecutionContext &exe_ctx, 101 Materializer *materializer); 102 103 //------------------------------------------------------------------ 104 /// [Used by ClangExpressionParser] For each variable that had an unknown 105 /// type at the beginning of parsing, determine its final type now. 106 /// 107 /// @return 108 /// True on success; false otherwise. 109 //------------------------------------------------------------------ 110 bool 111 ResolveUnknownTypes(); 112 113 //------------------------------------------------------------------ 114 /// Disable the state needed for parsing and IR transformation. 115 //------------------------------------------------------------------ 116 void 117 DidParse (); 118 119 //------------------------------------------------------------------ 120 /// [Used by IRForTarget] Add a variable to the list of persistent 121 /// variables for the process. 122 /// 123 /// @param[in] decl 124 /// The Clang declaration for the persistent variable, used for 125 /// lookup during parsing. 126 /// 127 /// @param[in] name 128 /// The name of the persistent variable, usually $something. 129 /// 130 /// @param[in] type 131 /// The type of the variable, in the Clang parser's context. 132 /// 133 /// @return 134 /// True on success; false otherwise. 135 //------------------------------------------------------------------ 136 bool 137 AddPersistentVariable (const clang::NamedDecl *decl, 138 const ConstString &name, 139 TypeFromParser type, 140 bool is_result, 141 bool is_lvalue); 142 143 //------------------------------------------------------------------ 144 /// [Used by IRForTarget] Add a variable to the struct that needs to 145 /// be materialized each time the expression runs. 146 /// 147 /// @param[in] decl 148 /// The Clang declaration for the variable. 149 /// 150 /// @param[in] name 151 /// The name of the variable. 152 /// 153 /// @param[in] value 154 /// The LLVM IR value for this variable. 155 /// 156 /// @param[in] size 157 /// The size of the variable in bytes. 158 /// 159 /// @param[in] alignment 160 /// The required alignment of the variable in bytes. 161 /// 162 /// @return 163 /// True on success; false otherwise. 164 //------------------------------------------------------------------ 165 bool 166 AddValueToStruct (const clang::NamedDecl *decl, 167 const ConstString &name, 168 llvm::Value *value, 169 size_t size, 170 off_t alignment); 171 172 //------------------------------------------------------------------ 173 /// [Used by IRForTarget] Finalize the struct, laying out the position 174 /// of each object in it. 175 /// 176 /// @return 177 /// True on success; false otherwise. 178 //------------------------------------------------------------------ 179 bool 180 DoStructLayout (); 181 182 //------------------------------------------------------------------ 183 /// [Used by IRForTarget] Get general information about the laid-out 184 /// struct after DoStructLayout() has been called. 185 /// 186 /// @param[out] num_elements 187 /// The number of elements in the struct. 188 /// 189 /// @param[out] size 190 /// The size of the struct, in bytes. 191 /// 192 /// @param[out] alignment 193 /// The alignment of the struct, in bytes. 194 /// 195 /// @return 196 /// True if the information could be retrieved; false otherwise. 197 //------------------------------------------------------------------ 198 bool 199 GetStructInfo (uint32_t &num_elements, 200 size_t &size, 201 off_t &alignment); 202 203 //------------------------------------------------------------------ 204 /// [Used by IRForTarget] Get specific information about one field 205 /// of the laid-out struct after DoStructLayout() has been called. 206 /// 207 /// @param[out] decl 208 /// The parsed Decl for the field, as generated by ClangASTSource 209 /// on ClangExpressionDeclMap's behalf. In the case of the result 210 /// value, this will have the name $__lldb_result even if the 211 /// result value ends up having the name $1. This is an 212 /// implementation detail of IRForTarget. 213 /// 214 /// @param[out] value 215 /// The IR value for the field (usually a GlobalVariable). In 216 /// the case of the result value, this will have the correct 217 /// name ($1, for instance). This is an implementation detail 218 /// of IRForTarget. 219 /// 220 /// @param[out] offset 221 /// The offset of the field from the beginning of the struct. 222 /// As long as the struct is aligned according to its required 223 /// alignment, this offset will align the field correctly. 224 /// 225 /// @param[out] name 226 /// The name of the field as used in materialization. 227 /// 228 /// @param[in] index 229 /// The index of the field about which information is requested. 230 /// 231 /// @return 232 /// True if the information could be retrieved; false otherwise. 233 //------------------------------------------------------------------ 234 bool 235 GetStructElement (const clang::NamedDecl *&decl, 236 llvm::Value *&value, 237 off_t &offset, 238 ConstString &name, 239 uint32_t index); 240 241 //------------------------------------------------------------------ 242 /// [Used by IRForTarget] Get information about a function given its 243 /// Decl. 244 /// 245 /// @param[in] decl 246 /// The parsed Decl for the Function, as generated by ClangASTSource 247 /// on ClangExpressionDeclMap's behalf. 248 /// 249 /// @param[out] ptr 250 /// The absolute address of the function in the target. 251 /// 252 /// @return 253 /// True if the information could be retrieved; false otherwise. 254 //------------------------------------------------------------------ 255 bool 256 GetFunctionInfo (const clang::NamedDecl *decl, 257 uint64_t &ptr); 258 259 //------------------------------------------------------------------ 260 /// [Used by IRForTarget] Get the address of a function given nothing 261 /// but its name. Some functions are needed but didn't get Decls made 262 /// during parsing -- specifically, sel_registerName is never called 263 /// in the generated IR but we need to call it nonetheless. 264 /// 265 /// @param[in] name 266 /// The name of the function. 267 /// 268 /// @param[out] ptr 269 /// The absolute address of the function in the target. 270 /// 271 /// @return 272 /// True if the address could be retrieved; false otherwise. 273 //------------------------------------------------------------------ 274 bool 275 GetFunctionAddress (const ConstString &name, 276 uint64_t &ptr); 277 278 //------------------------------------------------------------------ 279 /// [Used by IRForTarget] Get the address of a symbol given nothing 280 /// but its name. 281 /// 282 /// @param[in] target 283 /// The target to find the symbol in. If not provided, 284 /// then the current parsing context's Target. 285 /// 286 /// @param[in] process 287 /// The process to use. For Objective-C symbols, the process's 288 /// Objective-C language runtime may be queried if the process 289 /// is non-NULL. 290 /// 291 /// @param[in] name 292 /// The name of the symbol. 293 /// 294 /// @return 295 /// Valid load address for the symbol 296 //------------------------------------------------------------------ 297 lldb::addr_t 298 GetSymbolAddress (Target &target, 299 Process *process, 300 const ConstString &name, 301 lldb::SymbolType symbol_type); 302 303 lldb::addr_t 304 GetSymbolAddress (const ConstString &name, 305 lldb::SymbolType symbol_type); 306 307 //------------------------------------------------------------------ 308 /// [Used by IRInterpreter] Get basic target information. 309 /// 310 /// @param[out] byte_order 311 /// The byte order of the target. 312 /// 313 /// @param[out] address_byte_size 314 /// The size of a pointer in bytes. 315 /// 316 /// @return 317 /// True if the information could be determined; false 318 /// otherwise. 319 //------------------------------------------------------------------ 320 struct TargetInfo 321 { 322 lldb::ByteOrder byte_order; 323 size_t address_byte_size; 324 TargetInfoTargetInfo325 TargetInfo() : 326 byte_order(lldb::eByteOrderInvalid), 327 address_byte_size(0) 328 { 329 } 330 IsValidTargetInfo331 bool IsValid() 332 { 333 return (byte_order != lldb::eByteOrderInvalid && 334 address_byte_size != 0); 335 } 336 }; 337 TargetInfo GetTargetInfo(); 338 339 //------------------------------------------------------------------ 340 /// [Used by ClangASTSource] Find all entities matching a given name, 341 /// using a NameSearchContext to make Decls for them. 342 /// 343 /// @param[in] context 344 /// The NameSearchContext that can construct Decls for this name. 345 /// 346 /// @return 347 /// True on success; false otherwise. 348 //------------------------------------------------------------------ 349 void 350 FindExternalVisibleDecls (NameSearchContext &context); 351 352 //------------------------------------------------------------------ 353 /// Find all entities matching a given name in a given module/namespace, 354 /// using a NameSearchContext to make Decls for them. 355 /// 356 /// @param[in] context 357 /// The NameSearchContext that can construct Decls for this name. 358 /// 359 /// @param[in] module 360 /// If non-NULL, the module to query. 361 /// 362 /// @param[in] namespace_decl 363 /// If valid and module is non-NULL, the parent namespace. 364 /// 365 /// @param[in] name 366 /// The name as a plain C string. The NameSearchContext contains 367 /// a DeclarationName for the name so at first the name may seem 368 /// redundant, but ClangExpressionDeclMap operates in RTTI land so 369 /// it can't access DeclarationName. 370 /// 371 /// @param[in] current_id 372 /// The ID for the current FindExternalVisibleDecls invocation, 373 /// for logging purposes. 374 /// 375 /// @return 376 /// True on success; false otherwise. 377 //------------------------------------------------------------------ 378 void 379 FindExternalVisibleDecls (NameSearchContext &context, 380 lldb::ModuleSP module, 381 ClangNamespaceDecl &namespace_decl, 382 unsigned int current_id); 383 private: 384 ClangExpressionVariableList m_found_entities; ///< All entities that were looked up for the parser. 385 ClangExpressionVariableList m_struct_members; ///< All entities that need to be placed in the struct. 386 bool m_keep_result_in_memory; ///< True if result persistent variables generated by this expression should stay in memory. 387 388 //---------------------------------------------------------------------- 389 /// The following values should not live beyond parsing 390 //---------------------------------------------------------------------- 391 class ParserVars 392 { 393 public: ParserVars(ClangExpressionDeclMap & decl_map)394 ParserVars(ClangExpressionDeclMap &decl_map) : 395 m_exe_ctx(), 396 m_sym_ctx(), 397 m_persistent_vars(NULL), 398 m_enable_lookups(false), 399 m_materializer(NULL), 400 m_decl_map(decl_map) 401 { 402 } 403 404 Target * GetTarget()405 GetTarget() 406 { 407 if (m_exe_ctx.GetTargetPtr()) 408 return m_exe_ctx.GetTargetPtr(); 409 else if (m_sym_ctx.target_sp) 410 m_sym_ctx.target_sp.get(); 411 return NULL; 412 } 413 414 ExecutionContext m_exe_ctx; ///< The execution context to use when parsing. 415 SymbolContext m_sym_ctx; ///< The symbol context to use in finding variables and types. 416 ClangPersistentVariables *m_persistent_vars; ///< The persistent variables for the process. 417 bool m_enable_lookups; ///< Set to true during parsing if we have found the first "$__lldb" name. 418 TargetInfo m_target_info; ///< Basic information about the target. 419 Materializer *m_materializer; ///< If non-NULL, the materializer to use when reporting used variables. 420 private: 421 ClangExpressionDeclMap &m_decl_map; 422 DISALLOW_COPY_AND_ASSIGN (ParserVars); 423 }; 424 425 std::unique_ptr<ParserVars> m_parser_vars; 426 427 //---------------------------------------------------------------------- 428 /// Activate parser-specific variables 429 //---------------------------------------------------------------------- 430 void EnableParserVars()431 EnableParserVars() 432 { 433 if (!m_parser_vars.get()) 434 m_parser_vars.reset(new ParserVars(*this)); 435 } 436 437 //---------------------------------------------------------------------- 438 /// Deallocate parser-specific variables 439 //---------------------------------------------------------------------- 440 void DisableParserVars()441 DisableParserVars() 442 { 443 m_parser_vars.reset(); 444 } 445 446 //---------------------------------------------------------------------- 447 /// The following values contain layout information for the materialized 448 /// struct, but are not specific to a single materialization 449 //---------------------------------------------------------------------- 450 struct StructVars { StructVarsStructVars451 StructVars() : 452 m_struct_alignment(0), 453 m_struct_size(0), 454 m_struct_laid_out(false), 455 m_result_name(), 456 m_object_pointer_type(NULL, NULL) 457 { 458 } 459 460 off_t m_struct_alignment; ///< The alignment of the struct in bytes. 461 size_t m_struct_size; ///< The size of the struct in bytes. 462 bool m_struct_laid_out; ///< True if the struct has been laid out and the layout is valid (that is, no new fields have been added since). 463 ConstString m_result_name; ///< The name of the result variable ($1, for example) 464 TypeFromUser m_object_pointer_type; ///< The type of the "this" variable, if one exists 465 }; 466 467 std::unique_ptr<StructVars> m_struct_vars; 468 469 //---------------------------------------------------------------------- 470 /// Activate struct variables 471 //---------------------------------------------------------------------- 472 void EnableStructVars()473 EnableStructVars() 474 { 475 if (!m_struct_vars.get()) 476 m_struct_vars.reset(new struct StructVars); 477 } 478 479 //---------------------------------------------------------------------- 480 /// Deallocate struct variables 481 //---------------------------------------------------------------------- 482 void DisableStructVars()483 DisableStructVars() 484 { 485 m_struct_vars.reset(); 486 } 487 488 //---------------------------------------------------------------------- 489 /// Get this parser's ID for use in extracting parser- and JIT-specific 490 /// data from persistent variables. 491 //---------------------------------------------------------------------- 492 uint64_t GetParserID()493 GetParserID() 494 { 495 return (uint64_t)this; 496 } 497 498 //------------------------------------------------------------------ 499 /// Given a target, find a data symbol that has the given name. 500 /// 501 /// @param[in] target 502 /// The target to use as the basis for the search. 503 /// 504 /// @param[in] name 505 /// The name as a plain C string. 506 /// 507 /// @return 508 /// The LLDB Symbol found, or NULL if none was found. 509 //--------------------------------------------------------- 510 const Symbol * 511 FindGlobalDataSymbol (Target &target, 512 const ConstString &name); 513 514 //------------------------------------------------------------------ 515 /// Given a target, find a variable that matches the given name and 516 /// type. 517 /// 518 /// @param[in] target 519 /// The target to use as a basis for finding the variable. 520 /// 521 /// @param[in] module 522 /// If non-NULL, the module to search. 523 /// 524 /// @param[in] name 525 /// The name as a plain C string. 526 /// 527 /// @param[in] namespace_decl 528 /// If non-NULL and module is non-NULL, the parent namespace. 529 /// 530 /// @param[in] type 531 /// The required type for the variable. This function may be called 532 /// during parsing, in which case we don't know its type; hence the 533 /// default. 534 /// 535 /// @return 536 /// The LLDB Variable found, or NULL if none was found. 537 //------------------------------------------------------------------ 538 lldb::VariableSP 539 FindGlobalVariable (Target &target, 540 lldb::ModuleSP &module, 541 const ConstString &name, 542 ClangNamespaceDecl *namespace_decl, 543 TypeFromUser *type = NULL); 544 545 //------------------------------------------------------------------ 546 /// Get the value of a variable in a given execution context and return 547 /// the associated Types if needed. 548 /// 549 /// @param[in] var 550 /// The variable to evaluate. 551 /// 552 /// @param[out] var_location 553 /// The variable location value to fill in 554 /// 555 /// @param[out] found_type 556 /// The type of the found value, as it was found in the user process. 557 /// This is only useful when the variable is being inspected on behalf 558 /// of the parser, hence the default. 559 /// 560 /// @param[out] parser_type 561 /// The type of the found value, as it was copied into the parser's 562 /// AST context. This is only useful when the variable is being 563 /// inspected on behalf of the parser, hence the default. 564 /// 565 /// @param[in] decl 566 /// The Decl to be looked up. 567 /// 568 /// @return 569 /// Return true if the value was successfully filled in. 570 //------------------------------------------------------------------ 571 bool 572 GetVariableValue (lldb::VariableSP &var, 573 lldb_private::Value &var_location, 574 TypeFromUser *found_type = NULL, 575 TypeFromParser *parser_type = NULL); 576 577 //------------------------------------------------------------------ 578 /// Use the NameSearchContext to generate a Decl for the given LLDB 579 /// Variable, and put it in the Tuple list. 580 /// 581 /// @param[in] context 582 /// The NameSearchContext to use when constructing the Decl. 583 /// 584 /// @param[in] var 585 /// The LLDB Variable that needs a Decl. 586 /// 587 /// @param[in] valobj 588 /// The LLDB ValueObject for that variable. 589 //------------------------------------------------------------------ 590 void 591 AddOneVariable (NameSearchContext &context, 592 lldb::VariableSP var, 593 lldb::ValueObjectSP valobj, 594 unsigned int current_id); 595 596 //------------------------------------------------------------------ 597 /// Use the NameSearchContext to generate a Decl for the given 598 /// persistent variable, and put it in the list of found entities. 599 /// 600 /// @param[in] context 601 /// The NameSearchContext to use when constructing the Decl. 602 /// 603 /// @param[in] pvar 604 /// The persistent variable that needs a Decl. 605 /// 606 /// @param[in] current_id 607 /// The ID of the current invocation of FindExternalVisibleDecls 608 /// for logging purposes. 609 //------------------------------------------------------------------ 610 void 611 AddOneVariable (NameSearchContext &context, 612 lldb::ClangExpressionVariableSP &pvar_sp, 613 unsigned int current_id); 614 615 //------------------------------------------------------------------ 616 /// Use the NameSearchContext to generate a Decl for the given LLDB 617 /// symbol (treated as a variable), and put it in the list of found 618 /// entities. 619 /// 620 /// @param[in] context 621 /// The NameSearchContext to use when constructing the Decl. 622 /// 623 /// @param[in] var 624 /// The LLDB Variable that needs a Decl. 625 //------------------------------------------------------------------ 626 void 627 AddOneGenericVariable (NameSearchContext &context, 628 const Symbol &symbol, 629 unsigned int current_id); 630 631 //------------------------------------------------------------------ 632 /// Use the NameSearchContext to generate a Decl for the given 633 /// function. (Functions are not placed in the Tuple list.) Can 634 /// handle both fully typed functions and generic functions. 635 /// 636 /// @param[in] context 637 /// The NameSearchContext to use when constructing the Decl. 638 /// 639 /// @param[in] fun 640 /// The Function that needs to be created. If non-NULL, this is 641 /// a fully-typed function. 642 /// 643 /// @param[in] sym 644 /// The Symbol that corresponds to a function that needs to be 645 /// created with generic type (unitptr_t foo(...)). 646 //------------------------------------------------------------------ 647 void 648 AddOneFunction (NameSearchContext &context, 649 Function *fun, 650 Symbol *sym, 651 unsigned int current_id); 652 653 //------------------------------------------------------------------ 654 /// Use the NameSearchContext to generate a Decl for the given 655 /// register. 656 /// 657 /// @param[in] context 658 /// The NameSearchContext to use when constructing the Decl. 659 /// 660 /// @param[in] reg_info 661 /// The information corresponding to that register. 662 //------------------------------------------------------------------ 663 void 664 AddOneRegister (NameSearchContext &context, 665 const RegisterInfo *reg_info, 666 unsigned int current_id); 667 668 //------------------------------------------------------------------ 669 /// Use the NameSearchContext to generate a Decl for the given 670 /// type. (Types are not placed in the Tuple list.) 671 /// 672 /// @param[in] context 673 /// The NameSearchContext to use when constructing the Decl. 674 /// 675 /// @param[in] type 676 /// The type that needs to be created. 677 //------------------------------------------------------------------ 678 void 679 AddOneType (NameSearchContext &context, 680 TypeFromUser &type, 681 unsigned int current_id); 682 683 //------------------------------------------------------------------ 684 /// Copy a C++ class type into the parser's AST context and add a 685 /// member function declaration to it for the expression. 686 /// 687 /// @param[in] type 688 /// The type that needs to be created. 689 //------------------------------------------------------------------ 690 691 TypeFromParser 692 CopyClassType(TypeFromUser &type, 693 unsigned int current_id); 694 }; 695 696 } // namespace lldb_private 697 698 #endif // liblldb_ClangExpressionDeclMap_h_ 699