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/Symbol/ClangASTType.h" 26 #include "lldb/Target/Process.h" 27 28 namespace lldb_private 29 { 30 31 class ASTStructExtractor; 32 class ClangExpressionParser; 33 34 //---------------------------------------------------------------------- 35 /// @class ClangFunction ClangFunction.h "lldb/Expression/ClangFunction.h" 36 /// @brief Encapsulates a function that can be called. 37 /// 38 /// A given ClangFunction object can handle a single function signature. 39 /// Once constructed, it can set up any number of concurrent calls to 40 /// functions with that signature. 41 /// 42 /// It performs the call by synthesizing a structure that contains the pointer 43 /// to the function and the arguments that should be passed to that function, 44 /// and producing a special-purpose JIT-compiled function that accepts a void* 45 /// pointing to this struct as its only argument and calls the function in the 46 /// struct with the written arguments. This method lets Clang handle the 47 /// vagaries of function calling conventions. 48 /// 49 /// The simplest use of the ClangFunction is to construct it with a 50 /// function representative of the signature you want to use, then call 51 /// ExecuteFunction(ExecutionContext &, Stream &, Value &). 52 /// 53 /// If you need to reuse the arguments for several calls, you can call 54 /// InsertFunction() followed by WriteFunctionArguments(), which will return 55 /// the location of the args struct for the wrapper function in args_addr_ref. 56 /// 57 /// If you need to call the function on the thread plan stack, you can also 58 /// call InsertFunction() followed by GetThreadPlanToCallFunction(). 59 /// 60 /// Any of the methods that take arg_addr_ptr or arg_addr_ref can be passed 61 /// a pointer set to LLDB_INVALID_ADDRESS and new structure will be allocated 62 /// and its address returned in that variable. 63 /// 64 /// Any of the methods that take arg_addr_ptr can be passed NULL, and the 65 /// argument space will be managed for you. 66 //---------------------------------------------------------------------- 67 class ClangFunction : public ClangExpression 68 { 69 friend class ASTStructExtractor; 70 public: 71 //------------------------------------------------------------------ 72 /// Constructor 73 /// 74 /// @param[in] exe_scope 75 /// An execution context scope that gets us at least a target and 76 /// process. 77 /// 78 /// @param[in] function_ptr 79 /// The default function to be called. Can be overridden using 80 /// WriteFunctionArguments(). 81 /// 82 /// @param[in] ast_context 83 /// The AST context to evaluate argument types in. 84 /// 85 /// @param[in] arg_value_list 86 /// The default values to use when calling this function. Can 87 /// be overridden using WriteFunctionArguments(). 88 //------------------------------------------------------------------ 89 ClangFunction (ExecutionContextScope &exe_scope, 90 Function &function_ptr, 91 ClangASTContext *ast_context, 92 const ValueList &arg_value_list, 93 const char *name); 94 95 //------------------------------------------------------------------ 96 /// Constructor 97 /// 98 /// @param[in] exe_scope 99 /// An execution context scope that gets us at least a target and 100 /// process. 101 /// 102 /// @param[in] ast_context 103 /// The AST context to evaluate argument types in. 104 /// 105 /// @param[in] return_qualtype 106 /// An opaque Clang QualType for the function result. Should be 107 /// defined in ast_context. 108 /// 109 /// @param[in] function_address 110 /// The address of the function to call. 111 /// 112 /// @param[in] arg_value_list 113 /// The default values to use when calling this function. Can 114 /// be overridden using WriteFunctionArguments(). 115 //------------------------------------------------------------------ 116 ClangFunction (ExecutionContextScope &exe_scope, 117 const ClangASTType &return_type, 118 const Address& function_address, 119 const ValueList &arg_value_list, 120 const char *name); 121 122 //------------------------------------------------------------------ 123 /// Destructor 124 //------------------------------------------------------------------ 125 virtual 126 ~ClangFunction(); 127 128 //------------------------------------------------------------------ 129 /// Compile the wrapper function 130 /// 131 /// @param[in] errors 132 /// The stream to print parser errors to. 133 /// 134 /// @return 135 /// The number of errors. 136 //------------------------------------------------------------------ 137 unsigned 138 CompileFunction (Stream &errors); 139 140 //------------------------------------------------------------------ 141 /// Insert the default function wrapper and its default argument struct 142 /// 143 /// @param[in] exe_ctx 144 /// The execution context to insert the function and its arguments 145 /// into. 146 /// 147 /// @param[in,out] args_addr_ref 148 /// The address of the structure to write the arguments into. May 149 /// be LLDB_INVALID_ADDRESS; if it is, a new structure is allocated 150 /// and args_addr_ref is pointed to it. 151 /// 152 /// @param[in] errors 153 /// The stream to write errors to. 154 /// 155 /// @return 156 /// True on success; false otherwise. 157 //------------------------------------------------------------------ 158 bool 159 InsertFunction (ExecutionContext &exe_ctx, 160 lldb::addr_t &args_addr_ref, 161 Stream &errors); 162 163 //------------------------------------------------------------------ 164 /// Insert the default function wrapper (using the JIT) 165 /// 166 /// @param[in] exe_ctx 167 /// The execution context to insert the function and its arguments 168 /// into. 169 /// 170 /// @param[in] errors 171 /// The stream to write errors to. 172 /// 173 /// @return 174 /// True on success; false otherwise. 175 //------------------------------------------------------------------ 176 bool WriteFunctionWrapper (ExecutionContext &exe_ctx, 177 Stream &errors); 178 179 //------------------------------------------------------------------ 180 /// Insert the default function argument struct 181 /// 182 /// @param[in] exe_ctx 183 /// The execution context to insert the function and its arguments 184 /// into. 185 /// 186 /// @param[in,out] args_addr_ref 187 /// The address of the structure to write the arguments into. May 188 /// be LLDB_INVALID_ADDRESS; if it is, a new structure is allocated 189 /// and args_addr_ref is pointed to it. 190 /// 191 /// @param[in] errors 192 /// The stream to write errors to. 193 /// 194 /// @return 195 /// True on success; false otherwise. 196 //------------------------------------------------------------------ 197 bool WriteFunctionArguments (ExecutionContext &exe_ctx, 198 lldb::addr_t &args_addr_ref, 199 Stream &errors); 200 201 //------------------------------------------------------------------ 202 /// Insert an argument struct with a non-default function address and 203 /// non-default argument values 204 /// 205 /// @param[in] exe_ctx 206 /// The execution context to insert the function and its arguments 207 /// into. 208 /// 209 /// @param[in,out] args_addr_ref 210 /// The address of the structure to write the arguments into. May 211 /// be LLDB_INVALID_ADDRESS; if it is, a new structure is allocated 212 /// and args_addr_ref is pointed to it. 213 /// 214 /// @param[in] function_address 215 /// The address of the function to call. 216 /// 217 /// @param[in] arg_values 218 /// The values of the function's arguments. 219 /// 220 /// @param[in] errors 221 /// The stream to write errors to. 222 /// 223 /// @return 224 /// True on success; false otherwise. 225 //------------------------------------------------------------------ 226 bool WriteFunctionArguments (ExecutionContext &exe_ctx, 227 lldb::addr_t &args_addr_ref, 228 Address function_address, 229 ValueList &arg_values, 230 Stream &errors); 231 232 //------------------------------------------------------------------ 233 /// Run the function this ClangFunction was created with. 234 /// 235 /// This is the full version. 236 /// 237 /// @param[in] exe_ctx 238 /// The thread & process in which this function will run. 239 /// 240 /// @param[in] args_addr_ptr 241 /// If NULL, the function will take care of allocating & deallocating the wrapper 242 /// args structure. Otherwise, if set to LLDB_INVALID_ADDRESS, a new structure 243 /// will be allocated, filled and the address returned to you. You are responsible 244 /// for deallocating it. And if passed in with a value other than LLDB_INVALID_ADDRESS, 245 /// this should point to an already allocated structure with the values already written. 246 /// 247 /// @param[in] errors 248 /// Errors will be written here if there are any. 249 /// 250 /// @param[in] options 251 /// The options for this expression execution. 252 /// 253 /// @param[out] results 254 /// The result value will be put here after running the function. 255 /// 256 /// @return 257 /// Returns one of the ExpressionResults enum indicating function call status. 258 //------------------------------------------------------------------ 259 lldb::ExpressionResults 260 ExecuteFunction(ExecutionContext &exe_ctx, 261 lldb::addr_t *args_addr_ptr, 262 const EvaluateExpressionOptions &options, 263 Stream &errors, 264 Value &results); 265 266 //------------------------------------------------------------------ 267 /// Get a thread plan to run the function this ClangFunction was created with. 268 /// 269 /// @param[in] exe_ctx 270 /// The execution context to insert the function and its arguments 271 /// into. 272 /// 273 /// @param[in] func_addr 274 /// The address of the function in the target process. 275 /// 276 /// @param[in] args_addr 277 /// The address of the argument struct. 278 /// 279 /// @param[in] errors 280 /// The stream to write errors to. 281 /// 282 /// @param[in] stop_others 283 /// True if other threads should pause during execution. 284 /// 285 /// @param[in] unwind_on_error 286 /// True if the thread plan may simply be discarded if an error occurs. 287 /// 288 /// @return 289 /// A ThreadPlan shared pointer for executing the function. 290 //------------------------------------------------------------------ 291 lldb::ThreadPlanSP 292 GetThreadPlanToCallFunction (ExecutionContext &exe_ctx, 293 lldb::addr_t args_addr, 294 const EvaluateExpressionOptions &options, 295 Stream &errors); 296 297 //------------------------------------------------------------------ 298 /// Get the result of the function from its struct 299 /// 300 /// @param[in] exe_ctx 301 /// The execution context to retrieve the result from. 302 /// 303 /// @param[in] args_addr 304 /// The address of the argument struct. 305 /// 306 /// @param[out] ret_value 307 /// The value returned by the function. 308 /// 309 /// @return 310 /// True on success; false otherwise. 311 //------------------------------------------------------------------ 312 bool FetchFunctionResults (ExecutionContext &exe_ctx, 313 lldb::addr_t args_addr, 314 Value &ret_value); 315 316 //------------------------------------------------------------------ 317 /// Deallocate the arguments structure 318 /// 319 /// @param[in] exe_ctx 320 /// The execution context to insert the function and its arguments 321 /// into. 322 /// 323 /// @param[in] args_addr 324 /// The address of the argument struct. 325 //------------------------------------------------------------------ 326 void DeallocateFunctionResults (ExecutionContext &exe_ctx, 327 lldb::addr_t args_addr); 328 329 //------------------------------------------------------------------ 330 /// Interface for ClangExpression 331 //------------------------------------------------------------------ 332 333 //------------------------------------------------------------------ 334 /// Return the string that the parser should parse. Must be a full 335 /// translation unit. 336 //------------------------------------------------------------------ 337 const char * Text()338 Text () 339 { 340 return m_wrapper_function_text.c_str(); 341 } 342 343 //------------------------------------------------------------------ 344 /// Return the function name that should be used for executing the 345 /// expression. Text() should contain the definition of this 346 /// function. 347 //------------------------------------------------------------------ 348 const char * FunctionName()349 FunctionName () 350 { 351 return m_wrapper_function_name.c_str(); 352 } 353 354 //------------------------------------------------------------------ 355 /// Return the object that the parser should use when resolving external 356 /// values. May be NULL if everything should be self-contained. 357 //------------------------------------------------------------------ 358 ClangExpressionDeclMap * DeclMap()359 DeclMap () 360 { 361 return NULL; 362 } 363 364 //------------------------------------------------------------------ 365 /// Return the object that the parser should use when registering 366 /// local variables. May be NULL if the Expression doesn't care. 367 //------------------------------------------------------------------ 368 ClangExpressionVariableList * LocalVariables()369 LocalVariables () 370 { 371 return NULL; 372 } 373 374 //------------------------------------------------------------------ 375 /// Return the object that the parser should allow to access ASTs. 376 /// May be NULL if the ASTs do not need to be transformed. 377 /// 378 /// @param[in] passthrough 379 /// The ASTConsumer that the returned transformer should send 380 /// the ASTs to after transformation. 381 //------------------------------------------------------------------ 382 clang::ASTConsumer * 383 ASTTransformer (clang::ASTConsumer *passthrough); 384 385 //------------------------------------------------------------------ 386 /// Return true if validation code should be inserted into the 387 /// expression. 388 //------------------------------------------------------------------ 389 bool NeedsValidation()390 NeedsValidation () 391 { 392 return false; 393 } 394 395 //------------------------------------------------------------------ 396 /// Return true if external variables in the expression should be 397 /// resolved. 398 //------------------------------------------------------------------ 399 bool NeedsVariableResolution()400 NeedsVariableResolution () 401 { 402 return false; 403 } 404 405 ValueList GetArgumentValues()406 GetArgumentValues () const 407 { 408 return m_arg_values; 409 } 410 private: 411 //------------------------------------------------------------------ 412 // For ClangFunction only 413 //------------------------------------------------------------------ 414 415 // Note: the parser needs to be destructed before the execution unit, so 416 // declare the execution unit first. 417 std::shared_ptr<IRExecutionUnit> m_execution_unit_sp; 418 std::unique_ptr<ClangExpressionParser> m_parser; ///< The parser responsible for compiling the function. 419 lldb::ModuleWP m_jit_module_wp; 420 std::string m_name; ///< The name of this clang function - for debugging purposes. 421 422 Function *m_function_ptr; ///< The function we're going to call. May be NULL if we don't have debug info for the function. 423 Address m_function_addr; ///< If we don't have the FunctionSP, we at least need the address & return type. 424 ClangASTType m_function_return_type; ///< The opaque clang qual type for the function return type. 425 426 std::string m_wrapper_function_name; ///< The name of the wrapper function. 427 std::string m_wrapper_function_text; ///< The contents of the wrapper function. 428 std::string m_wrapper_struct_name; ///< The name of the struct that contains the target function address, arguments, and result. 429 std::list<lldb::addr_t> m_wrapper_args_addrs; ///< The addresses of the arguments to the wrapper function. 430 431 std::unique_ptr<ASTStructExtractor> m_struct_extractor; ///< The class that generates the argument struct below. 432 433 bool m_struct_valid; ///< True if the ASTStructExtractor has populated the variables below. 434 435 //------------------------------------------------------------------ 436 /// These values are populated by the ASTStructExtractor 437 size_t m_struct_size; ///< The size of the argument struct, in bytes. 438 std::vector<uint64_t> m_member_offsets; ///< The offset of each member in the struct, in bytes. 439 uint64_t m_return_size; ///< The size of the result variable, in bytes. 440 uint64_t m_return_offset; ///< The offset of the result variable in the struct, in bytes. 441 //------------------------------------------------------------------ 442 443 ValueList m_arg_values; ///< The default values of the arguments. 444 445 bool m_compiled; ///< True if the wrapper function has already been parsed. 446 bool m_JITted; ///< True if the wrapper function has already been JIT-compiled. 447 }; 448 449 } // Namespace lldb_private 450 451 #endif // lldb_ClangFunction_h_ 452