ExternalFunctions.cpp revision 199481
1//===-- ExternalFunctions.cpp - Implement External Functions --------------===// 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// This file contains both code to deal with invoking "external" functions, but 11// also contains code that implements "exported" external functions. 12// 13// There are currently two mechanisms for handling external functions in the 14// Interpreter. The first is to implement lle_* wrapper functions that are 15// specific to well-known library functions which manually translate the 16// arguments from GenericValues and make the call. If such a wrapper does 17// not exist, and libffi is available, then the Interpreter will attempt to 18// invoke the function using libffi, after finding its address. 19// 20//===----------------------------------------------------------------------===// 21 22#include "Interpreter.h" 23#include "llvm/DerivedTypes.h" 24#include "llvm/Module.h" 25#include "llvm/Config/config.h" // Detect libffi 26#include "llvm/Support/ErrorHandling.h" 27#include "llvm/System/DynamicLibrary.h" 28#include "llvm/Target/TargetData.h" 29#include "llvm/Support/ManagedStatic.h" 30#include "llvm/System/Mutex.h" 31#include <csignal> 32#include <cstdio> 33#include <map> 34#include <cmath> 35#include <cstring> 36 37#ifdef HAVE_FFI_CALL 38#ifdef HAVE_FFI_H 39#include <ffi.h> 40#define USE_LIBFFI 41#elif HAVE_FFI_FFI_H 42#include <ffi/ffi.h> 43#define USE_LIBFFI 44#endif 45#endif 46 47using namespace llvm; 48 49static ManagedStatic<sys::Mutex> FunctionsLock; 50 51typedef GenericValue (*ExFunc)(const FunctionType *, 52 const std::vector<GenericValue> &); 53static ManagedStatic<std::map<const Function *, ExFunc> > ExportedFunctions; 54static std::map<std::string, ExFunc> FuncNames; 55 56#ifdef USE_LIBFFI 57typedef void (*RawFunc)(); 58static ManagedStatic<std::map<const Function *, RawFunc> > RawFunctions; 59#endif 60 61static Interpreter *TheInterpreter; 62 63static char getTypeID(const Type *Ty) { 64 switch (Ty->getTypeID()) { 65 case Type::VoidTyID: return 'V'; 66 case Type::IntegerTyID: 67 switch (cast<IntegerType>(Ty)->getBitWidth()) { 68 case 1: return 'o'; 69 case 8: return 'B'; 70 case 16: return 'S'; 71 case 32: return 'I'; 72 case 64: return 'L'; 73 default: return 'N'; 74 } 75 case Type::FloatTyID: return 'F'; 76 case Type::DoubleTyID: return 'D'; 77 case Type::PointerTyID: return 'P'; 78 case Type::FunctionTyID:return 'M'; 79 case Type::StructTyID: return 'T'; 80 case Type::ArrayTyID: return 'A'; 81 case Type::OpaqueTyID: return 'O'; 82 default: return 'U'; 83 } 84} 85 86// Try to find address of external function given a Function object. 87// Please note, that interpreter doesn't know how to assemble a 88// real call in general case (this is JIT job), that's why it assumes, 89// that all external functions has the same (and pretty "general") signature. 90// The typical example of such functions are "lle_X_" ones. 91static ExFunc lookupFunction(const Function *F) { 92 // Function not found, look it up... start by figuring out what the 93 // composite function name should be. 94 std::string ExtName = "lle_"; 95 const FunctionType *FT = F->getFunctionType(); 96 for (unsigned i = 0, e = FT->getNumContainedTypes(); i != e; ++i) 97 ExtName += getTypeID(FT->getContainedType(i)); 98 ExtName + "_" + F->getNameStr(); 99 100 sys::ScopedLock Writer(*FunctionsLock); 101 ExFunc FnPtr = FuncNames[ExtName]; 102 if (FnPtr == 0) 103 FnPtr = FuncNames["lle_X_" + F->getNameStr()]; 104 if (FnPtr == 0) // Try calling a generic function... if it exists... 105 FnPtr = (ExFunc)(intptr_t) 106 sys::DynamicLibrary::SearchForAddressOfSymbol("lle_X_"+F->getNameStr()); 107 if (FnPtr != 0) 108 ExportedFunctions->insert(std::make_pair(F, FnPtr)); // Cache for later 109 return FnPtr; 110} 111 112#ifdef USE_LIBFFI 113static ffi_type *ffiTypeFor(const Type *Ty) { 114 switch (Ty->getTypeID()) { 115 case Type::VoidTyID: return &ffi_type_void; 116 case Type::IntegerTyID: 117 switch (cast<IntegerType>(Ty)->getBitWidth()) { 118 case 8: return &ffi_type_sint8; 119 case 16: return &ffi_type_sint16; 120 case 32: return &ffi_type_sint32; 121 case 64: return &ffi_type_sint64; 122 } 123 case Type::FloatTyID: return &ffi_type_float; 124 case Type::DoubleTyID: return &ffi_type_double; 125 case Type::PointerTyID: return &ffi_type_pointer; 126 default: break; 127 } 128 // TODO: Support other types such as StructTyID, ArrayTyID, OpaqueTyID, etc. 129 llvm_report_error("Type could not be mapped for use with libffi."); 130 return NULL; 131} 132 133static void *ffiValueFor(const Type *Ty, const GenericValue &AV, 134 void *ArgDataPtr) { 135 switch (Ty->getTypeID()) { 136 case Type::IntegerTyID: 137 switch (cast<IntegerType>(Ty)->getBitWidth()) { 138 case 8: { 139 int8_t *I8Ptr = (int8_t *) ArgDataPtr; 140 *I8Ptr = (int8_t) AV.IntVal.getZExtValue(); 141 return ArgDataPtr; 142 } 143 case 16: { 144 int16_t *I16Ptr = (int16_t *) ArgDataPtr; 145 *I16Ptr = (int16_t) AV.IntVal.getZExtValue(); 146 return ArgDataPtr; 147 } 148 case 32: { 149 int32_t *I32Ptr = (int32_t *) ArgDataPtr; 150 *I32Ptr = (int32_t) AV.IntVal.getZExtValue(); 151 return ArgDataPtr; 152 } 153 case 64: { 154 int64_t *I64Ptr = (int64_t *) ArgDataPtr; 155 *I64Ptr = (int64_t) AV.IntVal.getZExtValue(); 156 return ArgDataPtr; 157 } 158 } 159 case Type::FloatTyID: { 160 float *FloatPtr = (float *) ArgDataPtr; 161 *FloatPtr = AV.FloatVal; 162 return ArgDataPtr; 163 } 164 case Type::DoubleTyID: { 165 double *DoublePtr = (double *) ArgDataPtr; 166 *DoublePtr = AV.DoubleVal; 167 return ArgDataPtr; 168 } 169 case Type::PointerTyID: { 170 void **PtrPtr = (void **) ArgDataPtr; 171 *PtrPtr = GVTOP(AV); 172 return ArgDataPtr; 173 } 174 default: break; 175 } 176 // TODO: Support other types such as StructTyID, ArrayTyID, OpaqueTyID, etc. 177 llvm_report_error("Type value could not be mapped for use with libffi."); 178 return NULL; 179} 180 181static bool ffiInvoke(RawFunc Fn, Function *F, 182 const std::vector<GenericValue> &ArgVals, 183 const TargetData *TD, GenericValue &Result) { 184 ffi_cif cif; 185 const FunctionType *FTy = F->getFunctionType(); 186 const unsigned NumArgs = F->arg_size(); 187 188 // TODO: We don't have type information about the remaining arguments, because 189 // this information is never passed into ExecutionEngine::runFunction(). 190 if (ArgVals.size() > NumArgs && F->isVarArg()) { 191 llvm_report_error("Calling external var arg function '" + F->getName() 192 + "' is not supported by the Interpreter."); 193 } 194 195 unsigned ArgBytes = 0; 196 197 std::vector<ffi_type*> args(NumArgs); 198 for (Function::const_arg_iterator A = F->arg_begin(), E = F->arg_end(); 199 A != E; ++A) { 200 const unsigned ArgNo = A->getArgNo(); 201 const Type *ArgTy = FTy->getParamType(ArgNo); 202 args[ArgNo] = ffiTypeFor(ArgTy); 203 ArgBytes += TD->getTypeStoreSize(ArgTy); 204 } 205 206 SmallVector<uint8_t, 128> ArgData; 207 ArgData.resize(ArgBytes); 208 uint8_t *ArgDataPtr = ArgData.data(); 209 SmallVector<void*, 16> values(NumArgs); 210 for (Function::const_arg_iterator A = F->arg_begin(), E = F->arg_end(); 211 A != E; ++A) { 212 const unsigned ArgNo = A->getArgNo(); 213 const Type *ArgTy = FTy->getParamType(ArgNo); 214 values[ArgNo] = ffiValueFor(ArgTy, ArgVals[ArgNo], ArgDataPtr); 215 ArgDataPtr += TD->getTypeStoreSize(ArgTy); 216 } 217 218 const Type *RetTy = FTy->getReturnType(); 219 ffi_type *rtype = ffiTypeFor(RetTy); 220 221 if (ffi_prep_cif(&cif, FFI_DEFAULT_ABI, NumArgs, rtype, &args[0]) == FFI_OK) { 222 SmallVector<uint8_t, 128> ret; 223 if (RetTy->getTypeID() != Type::VoidTyID) 224 ret.resize(TD->getTypeStoreSize(RetTy)); 225 ffi_call(&cif, Fn, ret.data(), values.data()); 226 switch (RetTy->getTypeID()) { 227 case Type::IntegerTyID: 228 switch (cast<IntegerType>(RetTy)->getBitWidth()) { 229 case 8: Result.IntVal = APInt(8 , *(int8_t *) ret.data()); break; 230 case 16: Result.IntVal = APInt(16, *(int16_t*) ret.data()); break; 231 case 32: Result.IntVal = APInt(32, *(int32_t*) ret.data()); break; 232 case 64: Result.IntVal = APInt(64, *(int64_t*) ret.data()); break; 233 } 234 break; 235 case Type::FloatTyID: Result.FloatVal = *(float *) ret.data(); break; 236 case Type::DoubleTyID: Result.DoubleVal = *(double*) ret.data(); break; 237 case Type::PointerTyID: Result.PointerVal = *(void **) ret.data(); break; 238 default: break; 239 } 240 return true; 241 } 242 243 return false; 244} 245#endif // USE_LIBFFI 246 247GenericValue Interpreter::callExternalFunction(Function *F, 248 const std::vector<GenericValue> &ArgVals) { 249 TheInterpreter = this; 250 251 FunctionsLock->acquire(); 252 253 // Do a lookup to see if the function is in our cache... this should just be a 254 // deferred annotation! 255 std::map<const Function *, ExFunc>::iterator FI = ExportedFunctions->find(F); 256 if (ExFunc Fn = (FI == ExportedFunctions->end()) ? lookupFunction(F) 257 : FI->second) { 258 FunctionsLock->release(); 259 return Fn(F->getFunctionType(), ArgVals); 260 } 261 262#ifdef USE_LIBFFI 263 std::map<const Function *, RawFunc>::iterator RF = RawFunctions->find(F); 264 RawFunc RawFn; 265 if (RF == RawFunctions->end()) { 266 RawFn = (RawFunc)(intptr_t) 267 sys::DynamicLibrary::SearchForAddressOfSymbol(F->getName()); 268 if (RawFn != 0) 269 RawFunctions->insert(std::make_pair(F, RawFn)); // Cache for later 270 } else { 271 RawFn = RF->second; 272 } 273 274 FunctionsLock->release(); 275 276 GenericValue Result; 277 if (RawFn != 0 && ffiInvoke(RawFn, F, ArgVals, getTargetData(), Result)) 278 return Result; 279#endif // USE_LIBFFI 280 281 if (F->getName() == "__main") 282 errs() << "Tried to execute an unknown external function: " 283 << F->getType()->getDescription() << " __main\n"; 284 else 285 llvm_report_error("Tried to execute an unknown external function: " + 286 F->getType()->getDescription() + " " +F->getName()); 287#ifndef USE_LIBFFI 288 errs() << "Recompiling LLVM with --enable-libffi might help.\n"; 289#endif 290 return GenericValue(); 291} 292 293 294//===----------------------------------------------------------------------===// 295// Functions "exported" to the running application... 296// 297 298// Visual Studio warns about returning GenericValue in extern "C" linkage 299#ifdef _MSC_VER 300 #pragma warning(disable : 4190) 301#endif 302 303extern "C" { // Don't add C++ manglings to llvm mangling :) 304 305// void atexit(Function*) 306GenericValue lle_X_atexit(const FunctionType *FT, 307 const std::vector<GenericValue> &Args) { 308 assert(Args.size() == 1); 309 TheInterpreter->addAtExitHandler((Function*)GVTOP(Args[0])); 310 GenericValue GV; 311 GV.IntVal = 0; 312 return GV; 313} 314 315// void exit(int) 316GenericValue lle_X_exit(const FunctionType *FT, 317 const std::vector<GenericValue> &Args) { 318 TheInterpreter->exitCalled(Args[0]); 319 return GenericValue(); 320} 321 322// void abort(void) 323GenericValue lle_X_abort(const FunctionType *FT, 324 const std::vector<GenericValue> &Args) { 325 //FIXME: should we report or raise here? 326 //llvm_report_error("Interpreted program raised SIGABRT"); 327 raise (SIGABRT); 328 return GenericValue(); 329} 330 331// int sprintf(char *, const char *, ...) - a very rough implementation to make 332// output useful. 333GenericValue lle_X_sprintf(const FunctionType *FT, 334 const std::vector<GenericValue> &Args) { 335 char *OutputBuffer = (char *)GVTOP(Args[0]); 336 const char *FmtStr = (const char *)GVTOP(Args[1]); 337 unsigned ArgNo = 2; 338 339 // printf should return # chars printed. This is completely incorrect, but 340 // close enough for now. 341 GenericValue GV; 342 GV.IntVal = APInt(32, strlen(FmtStr)); 343 while (1) { 344 switch (*FmtStr) { 345 case 0: return GV; // Null terminator... 346 default: // Normal nonspecial character 347 sprintf(OutputBuffer++, "%c", *FmtStr++); 348 break; 349 case '\\': { // Handle escape codes 350 sprintf(OutputBuffer, "%c%c", *FmtStr, *(FmtStr+1)); 351 FmtStr += 2; OutputBuffer += 2; 352 break; 353 } 354 case '%': { // Handle format specifiers 355 char FmtBuf[100] = "", Buffer[1000] = ""; 356 char *FB = FmtBuf; 357 *FB++ = *FmtStr++; 358 char Last = *FB++ = *FmtStr++; 359 unsigned HowLong = 0; 360 while (Last != 'c' && Last != 'd' && Last != 'i' && Last != 'u' && 361 Last != 'o' && Last != 'x' && Last != 'X' && Last != 'e' && 362 Last != 'E' && Last != 'g' && Last != 'G' && Last != 'f' && 363 Last != 'p' && Last != 's' && Last != '%') { 364 if (Last == 'l' || Last == 'L') HowLong++; // Keep track of l's 365 Last = *FB++ = *FmtStr++; 366 } 367 *FB = 0; 368 369 switch (Last) { 370 case '%': 371 strcpy(Buffer, "%"); break; 372 case 'c': 373 sprintf(Buffer, FmtBuf, uint32_t(Args[ArgNo++].IntVal.getZExtValue())); 374 break; 375 case 'd': case 'i': 376 case 'u': case 'o': 377 case 'x': case 'X': 378 if (HowLong >= 1) { 379 if (HowLong == 1 && 380 TheInterpreter->getTargetData()->getPointerSizeInBits() == 64 && 381 sizeof(long) < sizeof(int64_t)) { 382 // Make sure we use %lld with a 64 bit argument because we might be 383 // compiling LLI on a 32 bit compiler. 384 unsigned Size = strlen(FmtBuf); 385 FmtBuf[Size] = FmtBuf[Size-1]; 386 FmtBuf[Size+1] = 0; 387 FmtBuf[Size-1] = 'l'; 388 } 389 sprintf(Buffer, FmtBuf, Args[ArgNo++].IntVal.getZExtValue()); 390 } else 391 sprintf(Buffer, FmtBuf,uint32_t(Args[ArgNo++].IntVal.getZExtValue())); 392 break; 393 case 'e': case 'E': case 'g': case 'G': case 'f': 394 sprintf(Buffer, FmtBuf, Args[ArgNo++].DoubleVal); break; 395 case 'p': 396 sprintf(Buffer, FmtBuf, (void*)GVTOP(Args[ArgNo++])); break; 397 case 's': 398 sprintf(Buffer, FmtBuf, (char*)GVTOP(Args[ArgNo++])); break; 399 default: 400 errs() << "<unknown printf code '" << *FmtStr << "'!>"; 401 ArgNo++; break; 402 } 403 strcpy(OutputBuffer, Buffer); 404 OutputBuffer += strlen(Buffer); 405 } 406 break; 407 } 408 } 409 return GV; 410} 411 412// int printf(const char *, ...) - a very rough implementation to make output 413// useful. 414GenericValue lle_X_printf(const FunctionType *FT, 415 const std::vector<GenericValue> &Args) { 416 char Buffer[10000]; 417 std::vector<GenericValue> NewArgs; 418 NewArgs.push_back(PTOGV((void*)&Buffer[0])); 419 NewArgs.insert(NewArgs.end(), Args.begin(), Args.end()); 420 GenericValue GV = lle_X_sprintf(FT, NewArgs); 421 outs() << Buffer; 422 return GV; 423} 424 425// int sscanf(const char *format, ...); 426GenericValue lle_X_sscanf(const FunctionType *FT, 427 const std::vector<GenericValue> &args) { 428 assert(args.size() < 10 && "Only handle up to 10 args to sscanf right now!"); 429 430 char *Args[10]; 431 for (unsigned i = 0; i < args.size(); ++i) 432 Args[i] = (char*)GVTOP(args[i]); 433 434 GenericValue GV; 435 GV.IntVal = APInt(32, sscanf(Args[0], Args[1], Args[2], Args[3], Args[4], 436 Args[5], Args[6], Args[7], Args[8], Args[9])); 437 return GV; 438} 439 440// int scanf(const char *format, ...); 441GenericValue lle_X_scanf(const FunctionType *FT, 442 const std::vector<GenericValue> &args) { 443 assert(args.size() < 10 && "Only handle up to 10 args to scanf right now!"); 444 445 char *Args[10]; 446 for (unsigned i = 0; i < args.size(); ++i) 447 Args[i] = (char*)GVTOP(args[i]); 448 449 GenericValue GV; 450 GV.IntVal = APInt(32, scanf( Args[0], Args[1], Args[2], Args[3], Args[4], 451 Args[5], Args[6], Args[7], Args[8], Args[9])); 452 return GV; 453} 454 455// int fprintf(FILE *, const char *, ...) - a very rough implementation to make 456// output useful. 457GenericValue lle_X_fprintf(const FunctionType *FT, 458 const std::vector<GenericValue> &Args) { 459 assert(Args.size() >= 2); 460 char Buffer[10000]; 461 std::vector<GenericValue> NewArgs; 462 NewArgs.push_back(PTOGV(Buffer)); 463 NewArgs.insert(NewArgs.end(), Args.begin()+1, Args.end()); 464 GenericValue GV = lle_X_sprintf(FT, NewArgs); 465 466 fputs(Buffer, (FILE *) GVTOP(Args[0])); 467 return GV; 468} 469 470} // End extern "C" 471 472// Done with externals; turn the warning back on 473#ifdef _MSC_VER 474 #pragma warning(default: 4190) 475#endif 476 477 478void Interpreter::initializeExternalFunctions() { 479 sys::ScopedLock Writer(*FunctionsLock); 480 FuncNames["lle_X_atexit"] = lle_X_atexit; 481 FuncNames["lle_X_exit"] = lle_X_exit; 482 FuncNames["lle_X_abort"] = lle_X_abort; 483 484 FuncNames["lle_X_printf"] = lle_X_printf; 485 FuncNames["lle_X_sprintf"] = lle_X_sprintf; 486 FuncNames["lle_X_sscanf"] = lle_X_sscanf; 487 FuncNames["lle_X_scanf"] = lle_X_scanf; 488 FuncNames["lle_X_fprintf"] = lle_X_fprintf; 489} 490