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 /// Run the function this ClangFunction was created with. 231 /// 232 /// This is the full version. 233 /// 234 /// @param[in] exe_ctx 235 /// The thread & process in which this function will run. 236 /// 237 /// @param[in] args_addr_ptr 238 /// If NULL, the function will take care of allocating & deallocating the wrapper 239 /// args structure. Otherwise, if set to LLDB_INVALID_ADDRESS, a new structure 240 /// will be allocated, filled and the address returned to you. You are responsible 241 /// for deallocating it. And if passed in with a value other than LLDB_INVALID_ADDRESS, 242 /// this should point to an already allocated structure with the values already written. 243 /// 244 /// @param[in] errors 245 /// Errors will be written here if there are any. 246 /// 247 /// @param[in] options 248 /// The options for this expression execution. 249 /// 250 /// @param[out] results 251 /// The result value will be put here after running the function. 252 /// 253 /// @return 254 /// Returns one of the ExecutionResults enum indicating function call status. 255 //------------------------------------------------------------------ 256 ExecutionResults 257 ExecuteFunction(ExecutionContext &exe_ctx, 258 lldb::addr_t *args_addr_ptr, 259 const EvaluateExpressionOptions &options, 260 Stream &errors, 261 Value &results); 262 263 //------------------------------------------------------------------ 264 /// Get a thread plan to run the function this ClangFunction was created with. 265 /// 266 /// @param[in] exe_ctx 267 /// The execution context to insert the function and its arguments 268 /// into. 269 /// 270 /// @param[in] func_addr 271 /// The address of the function in the target process. 272 /// 273 /// @param[in] args_addr 274 /// The address of the argument struct. 275 /// 276 /// @param[in] errors 277 /// The stream to write errors to. 278 /// 279 /// @param[in] stop_others 280 /// True if other threads should pause during execution. 281 /// 282 /// @param[in] unwind_on_error 283 /// True if the thread plan may simply be discarded if an error occurs. 284 /// 285 /// @return 286 /// A ThreadPlan for executing the function. 287 //------------------------------------------------------------------ 288 ThreadPlan * 289 GetThreadPlanToCallFunction (ExecutionContext &exe_ctx, 290 lldb::addr_t args_addr, 291 const EvaluateExpressionOptions &options, 292 Stream &errors); 293 294 //------------------------------------------------------------------ 295 /// Get the result of the function from its struct 296 /// 297 /// @param[in] exe_ctx 298 /// The execution context to retrieve the result from. 299 /// 300 /// @param[in] args_addr 301 /// The address of the argument struct. 302 /// 303 /// @param[out] ret_value 304 /// The value returned by the function. 305 /// 306 /// @return 307 /// True on success; false otherwise. 308 //------------------------------------------------------------------ 309 bool FetchFunctionResults (ExecutionContext &exe_ctx, 310 lldb::addr_t args_addr, 311 Value &ret_value); 312 313 //------------------------------------------------------------------ 314 /// Deallocate the arguments structure 315 /// 316 /// @param[in] exe_ctx 317 /// The execution context to insert the function and its arguments 318 /// into. 319 /// 320 /// @param[in] args_addr 321 /// The address of the argument struct. 322 //------------------------------------------------------------------ 323 void DeallocateFunctionResults (ExecutionContext &exe_ctx, 324 lldb::addr_t args_addr); 325 326 //------------------------------------------------------------------ 327 /// Interface for ClangExpression 328 //------------------------------------------------------------------ 329 330 //------------------------------------------------------------------ 331 /// Return the string that the parser should parse. Must be a full 332 /// translation unit. 333 //------------------------------------------------------------------ 334 const char * Text()335 Text () 336 { 337 return m_wrapper_function_text.c_str(); 338 } 339 340 //------------------------------------------------------------------ 341 /// Return the function name that should be used for executing the 342 /// expression. Text() should contain the definition of this 343 /// function. 344 //------------------------------------------------------------------ 345 const char * FunctionName()346 FunctionName () 347 { 348 return m_wrapper_function_name.c_str(); 349 } 350 351 //------------------------------------------------------------------ 352 /// Return the object that the parser should use when resolving external 353 /// values. May be NULL if everything should be self-contained. 354 //------------------------------------------------------------------ 355 ClangExpressionDeclMap * DeclMap()356 DeclMap () 357 { 358 return NULL; 359 } 360 361 //------------------------------------------------------------------ 362 /// Return the object that the parser should use when registering 363 /// local variables. May be NULL if the Expression doesn't care. 364 //------------------------------------------------------------------ 365 ClangExpressionVariableList * LocalVariables()366 LocalVariables () 367 { 368 return NULL; 369 } 370 371 //------------------------------------------------------------------ 372 /// Return the object that the parser should allow to access ASTs. 373 /// May be NULL if the ASTs do not need to be transformed. 374 /// 375 /// @param[in] passthrough 376 /// The ASTConsumer that the returned transformer should send 377 /// the ASTs to after transformation. 378 //------------------------------------------------------------------ 379 clang::ASTConsumer * 380 ASTTransformer (clang::ASTConsumer *passthrough); 381 382 //------------------------------------------------------------------ 383 /// Return true if validation code should be inserted into the 384 /// expression. 385 //------------------------------------------------------------------ 386 bool NeedsValidation()387 NeedsValidation () 388 { 389 return false; 390 } 391 392 //------------------------------------------------------------------ 393 /// Return true if external variables in the expression should be 394 /// resolved. 395 //------------------------------------------------------------------ 396 bool NeedsVariableResolution()397 NeedsVariableResolution () 398 { 399 return false; 400 } 401 402 ValueList GetArgumentValues()403 GetArgumentValues () const 404 { 405 return m_arg_values; 406 } 407 private: 408 //------------------------------------------------------------------ 409 // For ClangFunction only 410 //------------------------------------------------------------------ 411 412 std::unique_ptr<ClangExpressionParser> m_parser; ///< The parser responsible for compiling the function. 413 std::unique_ptr<IRExecutionUnit> m_execution_unit_ap; 414 415 Function *m_function_ptr; ///< The function we're going to call. May be NULL if we don't have debug info for the function. 416 Address m_function_addr; ///< If we don't have the FunctionSP, we at least need the address & return type. 417 ClangASTType m_function_return_type; ///< The opaque clang qual type for the function return type. 418 419 std::string m_wrapper_function_name; ///< The name of the wrapper function. 420 std::string m_wrapper_function_text; ///< The contents of the wrapper function. 421 std::string m_wrapper_struct_name; ///< The name of the struct that contains the target function address, arguments, and result. 422 std::list<lldb::addr_t> m_wrapper_args_addrs; ///< The addresses of the arguments to the wrapper function. 423 424 std::unique_ptr<ASTStructExtractor> m_struct_extractor; ///< The class that generates the argument struct below. 425 426 bool m_struct_valid; ///< True if the ASTStructExtractor has populated the variables below. 427 428 //------------------------------------------------------------------ 429 /// These values are populated by the ASTStructExtractor 430 size_t m_struct_size; ///< The size of the argument struct, in bytes. 431 std::vector<uint64_t> m_member_offsets; ///< The offset of each member in the struct, in bytes. 432 uint64_t m_return_size; ///< The size of the result variable, in bytes. 433 uint64_t m_return_offset; ///< The offset of the result variable in the struct, in bytes. 434 //------------------------------------------------------------------ 435 436 ValueList m_arg_values; ///< The default values of the arguments. 437 438 bool m_compiled; ///< True if the wrapper function has already been parsed. 439 bool m_JITted; ///< True if the wrapper function has already been JIT-compiled. 440 }; 441 442 } // Namespace lldb_private 443 444 #endif // lldb_ClangFunction_h_ 445