1 //===-- ClangFunction.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 lldb_ClangFunction_h_ 11 #define lldb_ClangFunction_h_ 12 13 // C Includes 14 // C++ Includes 15 #include <vector> 16 #include <list> 17 // Other libraries and framework includes 18 // Project includes 19 #include "lldb/Core/ClangForward.h" 20 #include "lldb/Core/Address.h" 21 #include "lldb/Core/ArchSpec.h" 22 #include "lldb/Core/Value.h" 23 #include "lldb/Core/ValueObjectList.h" 24 #include "lldb/Expression/ClangExpression.h" 25 #include "lldb/Target/Process.h" 26 27 namespace lldb_private 28 { 29 30 class ASTStructExtractor; 31 class ClangExpressionParser; 32 33 //---------------------------------------------------------------------- 34 /// @class ClangFunction ClangFunction.h "lldb/Expression/ClangFunction.h" 35 /// @brief Encapsulates a function that can be called. 36 /// 37 /// A given ClangFunction object can handle a single function signature. 38 /// Once constructed, it can set up any number of concurrent calls to 39 /// functions with that signature. 40 /// 41 /// It performs the call by synthesizing a structure that contains the pointer 42 /// to the function and the arguments that should be passed to that function, 43 /// and producing a special-purpose JIT-compiled function that accepts a void* 44 /// pointing to this struct as its only argument and calls the function in the 45 /// struct with the written arguments. This method lets Clang handle the 46 /// vagaries of function calling conventions. 47 /// 48 /// The simplest use of the ClangFunction is to construct it with a 49 /// function representative of the signature you want to use, then call 50 /// ExecuteFunction(ExecutionContext &, Stream &, Value &). 51 /// 52 /// If you need to reuse the arguments for several calls, you can call 53 /// InsertFunction() followed by WriteFunctionArguments(), which will return 54 /// the location of the args struct for the wrapper function in args_addr_ref. 55 /// 56 /// If you need to call the function on the thread plan stack, you can also 57 /// call InsertFunction() followed by GetThreadPlanToCallFunction(). 58 /// 59 /// Any of the methods that take arg_addr_ptr or arg_addr_ref can be passed 60 /// a pointer set to LLDB_INVALID_ADDRESS and new structure will be allocated 61 /// and its address returned in that variable. 62 /// 63 /// Any of the methods that take arg_addr_ptr can be passed NULL, and the 64 /// argument space will be managed for you. 65 //---------------------------------------------------------------------- 66 class ClangFunction : public ClangExpression 67 { 68 friend class ASTStructExtractor; 69 public: 70 //------------------------------------------------------------------ 71 /// Constructor 72 /// 73 /// @param[in] exe_scope 74 /// An execution context scope that gets us at least a target and 75 /// process. 76 /// 77 /// @param[in] function_ptr 78 /// The default function to be called. Can be overridden using 79 /// WriteFunctionArguments(). 80 /// 81 /// @param[in] ast_context 82 /// The AST context to evaluate argument types in. 83 /// 84 /// @param[in] arg_value_list 85 /// The default values to use when calling this function. Can 86 /// be overridden using WriteFunctionArguments(). 87 //------------------------------------------------------------------ 88 ClangFunction (ExecutionContextScope &exe_scope, 89 Function &function_ptr, 90 ClangASTContext *ast_context, 91 const ValueList &arg_value_list); 92 93 //------------------------------------------------------------------ 94 /// Constructor 95 /// 96 /// @param[in] exe_scope 97 /// An execution context scope that gets us at least a target and 98 /// process. 99 /// 100 /// @param[in] ast_context 101 /// The AST context to evaluate argument types in. 102 /// 103 /// @param[in] return_qualtype 104 /// An opaque Clang QualType for the function result. Should be 105 /// defined in ast_context. 106 /// 107 /// @param[in] function_address 108 /// The address of the function to call. 109 /// 110 /// @param[in] arg_value_list 111 /// The default values to use when calling this function. Can 112 /// be overridden using WriteFunctionArguments(). 113 //------------------------------------------------------------------ 114 ClangFunction (ExecutionContextScope &exe_scope, 115 const ClangASTType &return_type, 116 const Address& function_address, 117 const ValueList &arg_value_list); 118 119 //------------------------------------------------------------------ 120 /// Destructor 121 //------------------------------------------------------------------ 122 virtual 123 ~ClangFunction(); 124 125 //------------------------------------------------------------------ 126 /// Compile the wrapper function 127 /// 128 /// @param[in] errors 129 /// The stream to print parser errors to. 130 /// 131 /// @return 132 /// The number of errors. 133 //------------------------------------------------------------------ 134 unsigned 135 CompileFunction (Stream &errors); 136 137 //------------------------------------------------------------------ 138 /// Insert the default function wrapper and its default argument struct 139 /// 140 /// @param[in] exe_ctx 141 /// The execution context to insert the function and its arguments 142 /// into. 143 /// 144 /// @param[in,out] args_addr_ref 145 /// The address of the structure to write the arguments into. May 146 /// be LLDB_INVALID_ADDRESS; if it is, a new structure is allocated 147 /// and args_addr_ref is pointed to it. 148 /// 149 /// @param[in] errors 150 /// The stream to write errors to. 151 /// 152 /// @return 153 /// True on success; false otherwise. 154 //------------------------------------------------------------------ 155 bool 156 InsertFunction (ExecutionContext &exe_ctx, 157 lldb::addr_t &args_addr_ref, 158 Stream &errors); 159 160 //------------------------------------------------------------------ 161 /// Insert the default function wrapper (using the JIT) 162 /// 163 /// @param[in] exe_ctx 164 /// The execution context to insert the function and its arguments 165 /// into. 166 /// 167 /// @param[in] errors 168 /// The stream to write errors to. 169 /// 170 /// @return 171 /// True on success; false otherwise. 172 //------------------------------------------------------------------ 173 bool WriteFunctionWrapper (ExecutionContext &exe_ctx, 174 Stream &errors); 175 176 //------------------------------------------------------------------ 177 /// Insert the default function argument struct 178 /// 179 /// @param[in] exe_ctx 180 /// The execution context to insert the function and its arguments 181 /// into. 182 /// 183 /// @param[in,out] args_addr_ref 184 /// The address of the structure to write the arguments into. May 185 /// be LLDB_INVALID_ADDRESS; if it is, a new structure is allocated 186 /// and args_addr_ref is pointed to it. 187 /// 188 /// @param[in] errors 189 /// The stream to write errors to. 190 /// 191 /// @return 192 /// True on success; false otherwise. 193 //------------------------------------------------------------------ 194 bool WriteFunctionArguments (ExecutionContext &exe_ctx, 195 lldb::addr_t &args_addr_ref, 196 Stream &errors); 197 198 //------------------------------------------------------------------ 199 /// Insert an argument struct with a non-default function address and 200 /// non-default argument values 201 /// 202 /// @param[in] exe_ctx 203 /// The execution context to insert the function and its arguments 204 /// into. 205 /// 206 /// @param[in,out] args_addr_ref 207 /// The address of the structure to write the arguments into. May 208 /// be LLDB_INVALID_ADDRESS; if it is, a new structure is allocated 209 /// and args_addr_ref is pointed to it. 210 /// 211 /// @param[in] function_address 212 /// The address of the function to call. 213 /// 214 /// @param[in] arg_values 215 /// The values of the function's arguments. 216 /// 217 /// @param[in] errors 218 /// The stream to write errors to. 219 /// 220 /// @return 221 /// True on success; false otherwise. 222 //------------------------------------------------------------------ 223 bool WriteFunctionArguments (ExecutionContext &exe_ctx, 224 lldb::addr_t &args_addr_ref, 225 Address function_address, 226 ValueList &arg_values, 227 Stream &errors); 228 229 //------------------------------------------------------------------ 230 /// [Static] Execute a function, passing it a single void* parameter. 231 /// ClangFunction uses this to call the wrapper function. 232 /// 233 /// @param[in] exe_ctx 234 /// The execution context to insert the function and its arguments 235 /// into. 236 /// 237 /// @param[in] function_address 238 /// The address of the function in the target process. 239 /// 240 /// @param[in] void_arg 241 /// The value of the void* parameter. 242 /// 243 /// @param[in] stop_others 244 /// True if other threads should pause during execution. 245 /// 246 /// @param[in] try_all_threads 247 /// If the timeout expires, true if other threads should run. If 248 /// the function may try to take locks, this is useful. 249 /// 250 /// @param[in] unwind_on_error 251 /// If true, and the execution stops before completion, we unwind the 252 /// function call, and return the program state to what it was before the 253 /// execution. If false, we leave the program in the stopped state. 254 /// 255 /// @param[in] timeout_usec 256 /// Timeout value (0 for no timeout). If try_all_threads is true, then we 257 /// will try on one thread for the lesser of .25 sec and half the total timeout. 258 /// then switch to running all threads, otherwise this will be the total timeout. 259 /// 260 /// @param[in] errors 261 /// The stream to write errors to. 262 /// 263 /// @param[in] this_arg 264 /// If non-NULL, the function is invoked like a C++ method, with the 265 /// value pointed to by the pointer as its 'this' argument. 266 /// 267 /// @return 268 /// Returns one of the ExecutionResults enum indicating function call status. 269 //------------------------------------------------------------------ 270 static ExecutionResults 271 ExecuteFunction (ExecutionContext &exe_ctx, 272 lldb::addr_t function_address, 273 lldb::addr_t &void_arg, 274 bool stop_others, 275 bool try_all_threads, 276 bool unwind_on_error, 277 bool ignore_breakpoints, 278 uint32_t timeout_usec, 279 Stream &errors, 280 lldb::addr_t* this_arg = 0); 281 282 //------------------------------------------------------------------ 283 /// Run the function this ClangFunction was created with. 284 /// 285 /// This simple version will run the function stopping other threads 286 /// for a fixed timeout period (1000 usec) and if it does not complete, 287 /// we halt the process and try with all threads running. 288 /// 289 /// @param[in] exe_ctx 290 /// The thread & process in which this function will run. 291 /// 292 /// @param[in] errors 293 /// Errors will be written here if there are any. 294 /// 295 /// @param[out] results 296 /// The result value will be put here after running the function. 297 /// 298 /// @return 299 /// Returns one of the ExecutionResults enum indicating function call status. 300 //------------------------------------------------------------------ 301 ExecutionResults 302 ExecuteFunction(ExecutionContext &exe_ctx, 303 Stream &errors, 304 Value &results); 305 306 //------------------------------------------------------------------ 307 /// Run the function this ClangFunction was created with. 308 /// 309 /// This simple version will run the function obeying the stop_others 310 /// argument. There is no timeout. 311 /// 312 /// @param[in] exe_ctx 313 /// The thread & process in which this function will run. 314 /// 315 /// @param[in] errors 316 /// Errors will be written here if there are any. 317 /// 318 /// @param[in] stop_others 319 /// If \b true, run only this thread, if \b false let all threads run. 320 /// 321 /// @param[out] results 322 /// The result value will be put here after running the function. 323 /// 324 /// @return 325 /// Returns one of the ExecutionResults enum indicating function call status. 326 //------------------------------------------------------------------ 327 ExecutionResults 328 ExecuteFunction(ExecutionContext &exe_ctx, 329 Stream &errors, bool stop_others, 330 Value &results); 331 332 //------------------------------------------------------------------ 333 /// Run the function this ClangFunction was created with. 334 /// 335 /// This simple version will run the function on one thread. If \a timeout_usec 336 /// is not zero, we time out after that timeout. If \a try_all_threads is true, then we will 337 /// resume with all threads on, otherwise we halt the process, and eExecutionInterrupted will be returned. 338 /// 339 /// @param[in] exe_ctx 340 /// The thread & process in which this function will run. 341 /// 342 /// @param[in] errors 343 /// Errors will be written here if there are any. 344 /// 345 /// @param[in] timeout_usec 346 /// Timeout value (0 for no timeout). If try_all_threads is true, then we 347 /// will try on one thread for the lesser of .25 sec and half the total timeout. 348 /// then switch to running all threads, otherwise this will be the total timeout. 349 /// 350 /// @param[in] try_all_threads 351 /// If \b true, run only this thread, if \b false let all threads run. 352 /// 353 /// @param[out] results 354 /// The result value will be put here after running the function. 355 /// 356 /// @return 357 /// Returns one of the ExecutionResults enum indicating function call status. 358 //------------------------------------------------------------------ 359 ExecutionResults 360 ExecuteFunction(ExecutionContext &exe_ctx, 361 Stream &errors, 362 uint32_t single_thread_timeout_usec, 363 bool try_all_threads, 364 Value &results); 365 366 //------------------------------------------------------------------ 367 /// Run the function this ClangFunction was created with. 368 /// 369 /// This is the full version. 370 /// 371 /// @param[in] exe_ctx 372 /// The thread & process in which this function will run. 373 /// 374 /// @param[in] args_addr_ptr 375 /// If NULL, the function will take care of allocating & deallocating the wrapper 376 /// args structure. Otherwise, if set to LLDB_INVALID_ADDRESS, a new structure 377 /// will be allocated, filled and the address returned to you. You are responsible 378 /// for deallocating it. And if passed in with a value other than LLDB_INVALID_ADDRESS, 379 /// this should point to an already allocated structure with the values already written. 380 /// 381 /// @param[in] errors 382 /// Errors will be written here if there are any. 383 /// 384 /// @param[in] stop_others 385 /// If \b true, run only this thread, if \b false let all threads run. 386 /// 387 /// @param[in] timeout_usec 388 /// Timeout value (0 for no timeout). If try_all_threads is true, then we 389 /// will try on one thread for the lesser of .25 sec and half the total timeout. 390 /// then switch to running all threads, otherwise this will be the total timeout. 391 /// 392 /// 393 /// @param[in] try_all_threads 394 /// If \b true, run only this thread, if \b false let all threads run. 395 /// 396 /// @param[out] results 397 /// The result value will be put here after running the function. 398 /// 399 /// @return 400 /// Returns one of the ExecutionResults enum indicating function call status. 401 //------------------------------------------------------------------ 402 ExecutionResults 403 ExecuteFunction(ExecutionContext &exe_ctx, 404 lldb::addr_t *args_addr_ptr, 405 Stream &errors, 406 bool stop_others, 407 uint32_t timeout_usec, 408 bool try_all_threads, 409 bool unwind_on_error, 410 bool ignore_breakpoints, 411 Value &results); 412 413 //------------------------------------------------------------------ 414 /// [static] Get a thread plan to run a function. 415 /// 416 /// @param[in] exe_ctx 417 /// The execution context to insert the function and its arguments 418 /// into. 419 /// 420 /// @param[in] func_addr 421 /// The address of the function in the target process. 422 /// 423 /// @param[in] args_addr_ref 424 /// The value of the void* parameter. 425 /// 426 /// @param[in] errors 427 /// The stream to write errors to. 428 /// 429 /// @param[in] stop_others 430 /// True if other threads should pause during execution. 431 /// 432 /// @param[in] unwind_on_error 433 /// True if the thread plan may simply be discarded if an error occurs. 434 /// 435 /// @param[in] ignore_breakpoints 436 /// True if the expression execution will ignore breakpoint hits and continue executing. 437 /// 438 /// @param[in] this_arg 439 /// If non-NULL (and cmd_arg is NULL), the function is invoked like a C++ 440 /// method, with the value pointed to by the pointer as its 'this' 441 /// argument. 442 /// 443 /// @param[in] cmd_arg 444 /// If non-NULL, the function is invoked like an Objective-C method, with 445 /// this_arg in the 'self' slot and cmd_arg in the '_cmd' slot 446 /// 447 /// @return 448 /// A ThreadPlan for executing the function. 449 //------------------------------------------------------------------ 450 static ThreadPlan * 451 GetThreadPlanToCallFunction (ExecutionContext &exe_ctx, 452 lldb::addr_t func_addr, 453 lldb::addr_t &args_addr_ref, 454 Stream &errors, 455 bool stop_others, 456 bool unwind_on_error, 457 bool ignore_breakpoints, 458 lldb::addr_t *this_arg = 0, 459 lldb::addr_t *cmd_arg = 0); 460 461 //------------------------------------------------------------------ 462 /// Get a thread plan to run the function this ClangFunction was created with. 463 /// 464 /// @param[in] exe_ctx 465 /// The execution context to insert the function and its arguments 466 /// into. 467 /// 468 /// @param[in] func_addr 469 /// The address of the function in the target process. 470 /// 471 /// @param[in] args_addr_ref 472 /// The value of the void* parameter. 473 /// 474 /// @param[in] errors 475 /// The stream to write errors to. 476 /// 477 /// @param[in] stop_others 478 /// True if other threads should pause during execution. 479 /// 480 /// @param[in] unwind_on_error 481 /// True if the thread plan may simply be discarded if an error occurs. 482 /// 483 /// @return 484 /// A ThreadPlan for executing the function. 485 //------------------------------------------------------------------ 486 ThreadPlan * 487 GetThreadPlanToCallFunction (ExecutionContext &exe_ctx, 488 lldb::addr_t &args_addr_ref, 489 Stream &errors, 490 bool stop_others, 491 bool unwind_on_error = true, 492 bool ignore_breakpoints = true) 493 { 494 return ClangFunction::GetThreadPlanToCallFunction (exe_ctx, 495 m_jit_start_addr, 496 args_addr_ref, 497 errors, 498 stop_others, 499 unwind_on_error, 500 ignore_breakpoints); 501 } 502 503 //------------------------------------------------------------------ 504 /// Get the result of the function from its struct 505 /// 506 /// @param[in] exe_ctx 507 /// The execution context to retrieve the result from. 508 /// 509 /// @param[in] args_addr 510 /// The address of the argument struct. 511 /// 512 /// @param[in] ret_value 513 /// The value returned by the function. 514 /// 515 /// @return 516 /// True on success; false otherwise. 517 //------------------------------------------------------------------ 518 bool FetchFunctionResults (ExecutionContext &exe_ctx, 519 lldb::addr_t args_addr, 520 Value &ret_value); 521 522 //------------------------------------------------------------------ 523 /// Deallocate the arguments structure 524 /// 525 /// @param[in] exe_ctx 526 /// The execution context to insert the function and its arguments 527 /// into. 528 /// 529 /// @param[in] args_addr 530 /// The address of the argument struct. 531 //------------------------------------------------------------------ 532 void DeallocateFunctionResults (ExecutionContext &exe_ctx, 533 lldb::addr_t args_addr); 534 535 //------------------------------------------------------------------ 536 /// Interface for ClangExpression 537 //------------------------------------------------------------------ 538 539 //------------------------------------------------------------------ 540 /// Return the string that the parser should parse. Must be a full 541 /// translation unit. 542 //------------------------------------------------------------------ 543 const char * Text()544 Text () 545 { 546 return m_wrapper_function_text.c_str(); 547 } 548 549 //------------------------------------------------------------------ 550 /// Return the function name that should be used for executing the 551 /// expression. Text() should contain the definition of this 552 /// function. 553 //------------------------------------------------------------------ 554 const char * FunctionName()555 FunctionName () 556 { 557 return m_wrapper_function_name.c_str(); 558 } 559 560 //------------------------------------------------------------------ 561 /// Return the object that the parser should use when resolving external 562 /// values. May be NULL if everything should be self-contained. 563 //------------------------------------------------------------------ 564 ClangExpressionDeclMap * DeclMap()565 DeclMap () 566 { 567 return NULL; 568 } 569 570 //------------------------------------------------------------------ 571 /// Return the object that the parser should use when registering 572 /// local variables. May be NULL if the Expression doesn't care. 573 //------------------------------------------------------------------ 574 ClangExpressionVariableList * LocalVariables()575 LocalVariables () 576 { 577 return NULL; 578 } 579 580 //------------------------------------------------------------------ 581 /// Return the object that the parser should allow to access ASTs. 582 /// May be NULL if the ASTs do not need to be transformed. 583 /// 584 /// @param[in] passthrough 585 /// The ASTConsumer that the returned transformer should send 586 /// the ASTs to after transformation. 587 //------------------------------------------------------------------ 588 clang::ASTConsumer * 589 ASTTransformer (clang::ASTConsumer *passthrough); 590 591 //------------------------------------------------------------------ 592 /// Return true if validation code should be inserted into the 593 /// expression. 594 //------------------------------------------------------------------ 595 bool NeedsValidation()596 NeedsValidation () 597 { 598 return false; 599 } 600 601 //------------------------------------------------------------------ 602 /// Return true if external variables in the expression should be 603 /// resolved. 604 //------------------------------------------------------------------ 605 bool NeedsVariableResolution()606 NeedsVariableResolution () 607 { 608 return false; 609 } 610 611 ValueList GetArgumentValues()612 GetArgumentValues () const 613 { 614 return m_arg_values; 615 } 616 private: 617 //------------------------------------------------------------------ 618 // For ClangFunction only 619 //------------------------------------------------------------------ 620 621 std::unique_ptr<ClangExpressionParser> m_parser; ///< The parser responsible for compiling the function. 622 std::unique_ptr<IRExecutionUnit> m_execution_unit_ap; 623 624 Function *m_function_ptr; ///< The function we're going to call. May be NULL if we don't have debug info for the function. 625 Address m_function_addr; ///< If we don't have the FunctionSP, we at least need the address & return type. 626 ClangASTType m_function_return_type; ///< The opaque clang qual type for the function return type. 627 ClangASTContext *m_clang_ast_context; ///< This is the clang_ast_context that we're getting types from the and value, and the function return the function pointer is NULL. 628 629 std::string m_wrapper_function_name; ///< The name of the wrapper function. 630 std::string m_wrapper_function_text; ///< The contents of the wrapper function. 631 std::string m_wrapper_struct_name; ///< The name of the struct that contains the target function address, arguments, and result. 632 std::list<lldb::addr_t> m_wrapper_args_addrs; ///< The addresses of the arguments to the wrapper function. 633 634 bool m_struct_valid; ///< True if the ASTStructExtractor has populated the variables below. 635 636 //------------------------------------------------------------------ 637 /// These values are populated by the ASTStructExtractor 638 size_t m_struct_size; ///< The size of the argument struct, in bytes. 639 std::vector<uint64_t> m_member_offsets; ///< The offset of each member in the struct, in bytes. 640 uint64_t m_return_size; ///< The size of the result variable, in bytes. 641 uint64_t m_return_offset; ///< The offset of the result variable in the struct, in bytes. 642 //------------------------------------------------------------------ 643 644 ValueList m_arg_values; ///< The default values of the arguments. 645 646 bool m_compiled; ///< True if the wrapper function has already been parsed. 647 bool m_JITted; ///< True if the wrapper function has already been JIT-compiled. 648 }; 649 650 } // Namespace lldb_private 651 652 #endif // lldb_ClangFunction_h_ 653