1 //===-- ExternalFunctions.cpp - Implement External Functions --------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains both code to deal with invoking "external" functions, but
11 // also contains code that implements "exported" external functions.
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.
20 //===----------------------------------------------------------------------===//
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"
49 static ManagedStatic<sys::Mutex> FunctionsLock;
51 typedef GenericValue (*ExFunc)(const FunctionType *,
52 const std::vector<GenericValue> &);
53 static ManagedStatic<std::map<const Function *, ExFunc> > ExportedFunctions;
54 static std::map<std::string, ExFunc> FuncNames;
57 typedef void (*RawFunc)();
58 static ManagedStatic<std::map<const Function *, RawFunc> > RawFunctions;
61 static Interpreter *TheInterpreter;
63 static 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()) {
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';
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.
91 static 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();
100 sys::ScopedLock Writer(*FunctionsLock);
101 ExFunc FnPtr = FuncNames[ExtName];
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());
108 ExportedFunctions->insert(std::make_pair(F, FnPtr)); // Cache for later
113 static 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;
123 case Type::FloatTyID: return &ffi_type_float;
124 case Type::DoubleTyID: return &ffi_type_double;
125 case Type::PointerTyID: return &ffi_type_pointer;
128 // TODO: Support other types such as StructTyID, ArrayTyID, OpaqueTyID, etc.
129 llvm_report_error("Type could not be mapped for use with libffi.");
133 static void *ffiValueFor(const Type *Ty, const GenericValue &AV,
135 switch (Ty->getTypeID()) {
136 case Type::IntegerTyID:
137 switch (cast<IntegerType>(Ty)->getBitWidth()) {
139 int8_t *I8Ptr = (int8_t *) ArgDataPtr;
140 *I8Ptr = (int8_t) AV.IntVal.getZExtValue();
144 int16_t *I16Ptr = (int16_t *) ArgDataPtr;
145 *I16Ptr = (int16_t) AV.IntVal.getZExtValue();
149 int32_t *I32Ptr = (int32_t *) ArgDataPtr;
150 *I32Ptr = (int32_t) AV.IntVal.getZExtValue();
154 int64_t *I64Ptr = (int64_t *) ArgDataPtr;
155 *I64Ptr = (int64_t) AV.IntVal.getZExtValue();
159 case Type::FloatTyID: {
160 float *FloatPtr = (float *) ArgDataPtr;
161 *FloatPtr = AV.DoubleVal;
164 case Type::DoubleTyID: {
165 double *DoublePtr = (double *) ArgDataPtr;
166 *DoublePtr = AV.DoubleVal;
169 case Type::PointerTyID: {
170 void **PtrPtr = (void **) ArgDataPtr;
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.");
181 static bool ffiInvoke(RawFunc Fn, Function *F,
182 const std::vector<GenericValue> &ArgVals,
183 const TargetData *TD, GenericValue &Result) {
185 const FunctionType *FTy = F->getFunctionType();
186 const unsigned NumArgs = F->arg_size();
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.");
195 unsigned ArgBytes = 0;
197 std::vector<ffi_type*> args(NumArgs);
198 for (Function::const_arg_iterator A = F->arg_begin(), E = F->arg_end();
200 const unsigned ArgNo = A->getArgNo();
201 const Type *ArgTy = FTy->getParamType(ArgNo);
202 args[ArgNo] = ffiTypeFor(ArgTy);
203 ArgBytes += TD->getTypeStoreSize(ArgTy);
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();
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);
218 const Type *RetTy = FTy->getReturnType();
219 ffi_type *rtype = ffiTypeFor(RetTy);
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;
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;
247 GenericValue Interpreter::callExternalFunction(Function *F,
248 const std::vector<GenericValue> &ArgVals) {
249 TheInterpreter = this;
251 FunctionsLock->acquire();
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)
258 FunctionsLock->release();
259 return Fn(F->getFunctionType(), ArgVals);
263 std::map<const Function *, RawFunc>::iterator RF = RawFunctions->find(F);
265 if (RF == RawFunctions->end()) {
266 RawFn = (RawFunc)(intptr_t)
267 sys::DynamicLibrary::SearchForAddressOfSymbol(F->getName());
269 RawFunctions->insert(std::make_pair(F, RawFn)); // Cache for later
274 FunctionsLock->release();
277 if (RawFn != 0 && ffiInvoke(RawFn, F, ArgVals, getTargetData(), Result))
281 if (F->getName() == "__main")
282 errs() << "Tried to execute an unknown external function: "
283 << F->getType()->getDescription() << " __main\n";
285 llvm_report_error("Tried to execute an unknown external function: " +
286 F->getType()->getDescription() + " " +F->getName());
287 return GenericValue();
291 //===----------------------------------------------------------------------===//
292 // Functions "exported" to the running application...
295 // Visual Studio warns about returning GenericValue in extern "C" linkage
297 #pragma warning(disable : 4190)
300 extern "C" { // Don't add C++ manglings to llvm mangling :)
302 // void atexit(Function*)
303 GenericValue lle_X_atexit(const FunctionType *FT,
304 const std::vector<GenericValue> &Args) {
305 assert(Args.size() == 1);
306 TheInterpreter->addAtExitHandler((Function*)GVTOP(Args[0]));
313 GenericValue lle_X_exit(const FunctionType *FT,
314 const std::vector<GenericValue> &Args) {
315 TheInterpreter->exitCalled(Args[0]);
316 return GenericValue();
320 GenericValue lle_X_abort(const FunctionType *FT,
321 const std::vector<GenericValue> &Args) {
322 //FIXME: should we report or raise here?
323 //llvm_report_error("Interpreted program raised SIGABRT");
325 return GenericValue();
328 // int sprintf(char *, const char *, ...) - a very rough implementation to make
330 GenericValue lle_X_sprintf(const FunctionType *FT,
331 const std::vector<GenericValue> &Args) {
332 char *OutputBuffer = (char *)GVTOP(Args[0]);
333 const char *FmtStr = (const char *)GVTOP(Args[1]);
336 // printf should return # chars printed. This is completely incorrect, but
337 // close enough for now.
339 GV.IntVal = APInt(32, strlen(FmtStr));
342 case 0: return GV; // Null terminator...
343 default: // Normal nonspecial character
344 sprintf(OutputBuffer++, "%c", *FmtStr++);
346 case '\\': { // Handle escape codes
347 sprintf(OutputBuffer, "%c%c", *FmtStr, *(FmtStr+1));
348 FmtStr += 2; OutputBuffer += 2;
351 case '%': { // Handle format specifiers
352 char FmtBuf[100] = "", Buffer[1000] = "";
355 char Last = *FB++ = *FmtStr++;
356 unsigned HowLong = 0;
357 while (Last != 'c' && Last != 'd' && Last != 'i' && Last != 'u' &&
358 Last != 'o' && Last != 'x' && Last != 'X' && Last != 'e' &&
359 Last != 'E' && Last != 'g' && Last != 'G' && Last != 'f' &&
360 Last != 'p' && Last != 's' && Last != '%') {
361 if (Last == 'l' || Last == 'L') HowLong++; // Keep track of l's
362 Last = *FB++ = *FmtStr++;
368 strcpy(Buffer, "%"); break;
370 sprintf(Buffer, FmtBuf, uint32_t(Args[ArgNo++].IntVal.getZExtValue()));
377 TheInterpreter->getTargetData()->getPointerSizeInBits() == 64 &&
378 sizeof(long) < sizeof(int64_t)) {
379 // Make sure we use %lld with a 64 bit argument because we might be
380 // compiling LLI on a 32 bit compiler.
381 unsigned Size = strlen(FmtBuf);
382 FmtBuf[Size] = FmtBuf[Size-1];
384 FmtBuf[Size-1] = 'l';
386 sprintf(Buffer, FmtBuf, Args[ArgNo++].IntVal.getZExtValue());
388 sprintf(Buffer, FmtBuf,uint32_t(Args[ArgNo++].IntVal.getZExtValue()));
390 case 'e': case 'E': case 'g': case 'G': case 'f':
391 sprintf(Buffer, FmtBuf, Args[ArgNo++].DoubleVal); break;
393 sprintf(Buffer, FmtBuf, (void*)GVTOP(Args[ArgNo++])); break;
395 sprintf(Buffer, FmtBuf, (char*)GVTOP(Args[ArgNo++])); break;
397 errs() << "<unknown printf code '" << *FmtStr << "'!>";
400 strcpy(OutputBuffer, Buffer);
401 OutputBuffer += strlen(Buffer);
409 // int printf(const char *, ...) - a very rough implementation to make output
411 GenericValue lle_X_printf(const FunctionType *FT,
412 const std::vector<GenericValue> &Args) {
414 std::vector<GenericValue> NewArgs;
415 NewArgs.push_back(PTOGV((void*)&Buffer[0]));
416 NewArgs.insert(NewArgs.end(), Args.begin(), Args.end());
417 GenericValue GV = lle_X_sprintf(FT, NewArgs);
422 static void ByteswapSCANFResults(LLVMContext &C,
423 const char *Fmt, void *Arg0, void *Arg1,
424 void *Arg2, void *Arg3, void *Arg4, void *Arg5,
425 void *Arg6, void *Arg7, void *Arg8) {
426 void *Args[] = { Arg0, Arg1, Arg2, Arg3, Arg4, Arg5, Arg6, Arg7, Arg8, 0 };
428 // Loop over the format string, munging read values as appropriate (performs
429 // byteswaps as necessary).
433 // Read any flag characters that may be present...
434 bool Suppress = false;
437 bool LongLong = false; // long long or long double
441 case '*': Suppress = true; break;
442 case 'a': /*Allocate = true;*/ break; // We don't need to track this
443 case 'h': Half = true; break;
444 case 'l': Long = true; break;
446 case 'L': LongLong = true; break;
448 if (Fmt[-1] > '9' || Fmt[-1] < '0') // Ignore field width specs
454 // Read the conversion character
455 if (!Suppress && Fmt[-1] != '%') { // Nothing to do?
460 case 'i': case 'o': case 'u': case 'x': case 'X': case 'n': case 'p':
462 if (Long || LongLong) {
463 Size = 8; Ty = Type::getInt64Ty(C);
465 Size = 4; Ty = Type::getInt16Ty(C);
467 Size = 4; Ty = Type::getInt32Ty(C);
471 case 'e': case 'g': case 'E': case 'f':
472 if (Long || LongLong) {
473 Size = 8; Ty = Type::getDoubleTy(C);
475 Size = 4; Ty = Type::getFloatTy(C);
479 case 's': case 'c': case '[': // No byteswap needed
481 Ty = Type::getInt8Ty(C);
489 void *Arg = Args[ArgNo++];
490 memcpy(&GV, Arg, Size);
491 TheInterpreter->StoreValueToMemory(GV, (GenericValue*)Arg, Ty);
498 // int sscanf(const char *format, ...);
499 GenericValue lle_X_sscanf(const FunctionType *FT,
500 const std::vector<GenericValue> &args) {
501 assert(args.size() < 10 && "Only handle up to 10 args to sscanf right now!");
504 for (unsigned i = 0; i < args.size(); ++i)
505 Args[i] = (char*)GVTOP(args[i]);
508 GV.IntVal = APInt(32, sscanf(Args[0], Args[1], Args[2], Args[3], Args[4],
509 Args[5], Args[6], Args[7], Args[8], Args[9]));
513 // int scanf(const char *format, ...);
514 GenericValue lle_X_scanf(const FunctionType *FT,
515 const std::vector<GenericValue> &args) {
516 assert(args.size() < 10 && "Only handle up to 10 args to scanf right now!");
519 for (unsigned i = 0; i < args.size(); ++i)
520 Args[i] = (char*)GVTOP(args[i]);
523 GV.IntVal = APInt(32, scanf( Args[0], Args[1], Args[2], Args[3], Args[4],
524 Args[5], Args[6], Args[7], Args[8], Args[9]));
528 // int fprintf(FILE *, const char *, ...) - a very rough implementation to make
530 GenericValue lle_X_fprintf(const FunctionType *FT,
531 const std::vector<GenericValue> &Args) {
532 assert(Args.size() >= 2);
534 std::vector<GenericValue> NewArgs;
535 NewArgs.push_back(PTOGV(Buffer));
536 NewArgs.insert(NewArgs.end(), Args.begin()+1, Args.end());
537 GenericValue GV = lle_X_sprintf(FT, NewArgs);
539 fputs(Buffer, (FILE *) GVTOP(Args[0]));
545 // Done with externals; turn the warning back on
547 #pragma warning(default: 4190)
551 void Interpreter::initializeExternalFunctions() {
552 sys::ScopedLock Writer(*FunctionsLock);
553 FuncNames["lle_X_atexit"] = lle_X_atexit;
554 FuncNames["lle_X_exit"] = lle_X_exit;
555 FuncNames["lle_X_abort"] = lle_X_abort;
557 FuncNames["lle_X_printf"] = lle_X_printf;
558 FuncNames["lle_X_sprintf"] = lle_X_sprintf;
559 FuncNames["lle_X_sscanf"] = lle_X_sscanf;
560 FuncNames["lle_X_scanf"] = lle_X_scanf;
561 FuncNames["lle_X_fprintf"] = lle_X_fprintf;