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/Streams.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)(void);
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->getName();
100 sys::ScopedLock Writer(&*FunctionsLock);
101 ExFunc FnPtr = FuncNames[ExtName];
103 FnPtr = FuncNames["lle_X_"+F->getName()];
104 if (FnPtr == 0) // Try calling a generic function... if it exists...
105 FnPtr = (ExFunc)(intptr_t)sys::DynamicLibrary::SearchForAddressOfSymbol(
106 ("lle_X_"+F->getName()).c_str());
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 cerr << "Type could not be mapped for use with libffi.\n";
134 static void *ffiValueFor(const Type *Ty, const GenericValue &AV,
136 switch (Ty->getTypeID()) {
137 case Type::IntegerTyID:
138 switch (cast<IntegerType>(Ty)->getBitWidth()) {
140 int8_t *I8Ptr = (int8_t *) ArgDataPtr;
141 *I8Ptr = (int8_t) AV.IntVal.getZExtValue();
145 int16_t *I16Ptr = (int16_t *) ArgDataPtr;
146 *I16Ptr = (int16_t) AV.IntVal.getZExtValue();
150 int32_t *I32Ptr = (int32_t *) ArgDataPtr;
151 *I32Ptr = (int32_t) AV.IntVal.getZExtValue();
155 int64_t *I64Ptr = (int64_t *) ArgDataPtr;
156 *I64Ptr = (int64_t) AV.IntVal.getZExtValue();
160 case Type::FloatTyID: {
161 float *FloatPtr = (float *) ArgDataPtr;
162 *FloatPtr = AV.DoubleVal;
165 case Type::DoubleTyID: {
166 double *DoublePtr = (double *) ArgDataPtr;
167 *DoublePtr = AV.DoubleVal;
170 case Type::PointerTyID: {
171 void **PtrPtr = (void **) ArgDataPtr;
177 // TODO: Support other types such as StructTyID, ArrayTyID, OpaqueTyID, etc.
178 cerr << "Type value could not be mapped for use with libffi.\n";
183 static bool ffiInvoke(RawFunc Fn, Function *F,
184 const std::vector<GenericValue> &ArgVals,
185 const TargetData *TD, GenericValue &Result) {
187 const FunctionType *FTy = F->getFunctionType();
188 const unsigned NumArgs = F->arg_size();
190 // TODO: We don't have type information about the remaining arguments, because
191 // this information is never passed into ExecutionEngine::runFunction().
192 if (ArgVals.size() > NumArgs && F->isVarArg()) {
193 cerr << "Calling external var arg function '" << F->getName()
194 << "' is not supported by the Interpreter.\n";
198 unsigned ArgBytes = 0;
200 std::vector<ffi_type*> args(NumArgs);
201 for (Function::const_arg_iterator A = F->arg_begin(), E = F->arg_end();
203 const unsigned ArgNo = A->getArgNo();
204 const Type *ArgTy = FTy->getParamType(ArgNo);
205 args[ArgNo] = ffiTypeFor(ArgTy);
206 ArgBytes += TD->getTypeStoreSize(ArgTy);
209 uint8_t *ArgData = (uint8_t*) alloca(ArgBytes);
210 uint8_t *ArgDataPtr = ArgData;
211 std::vector<void*> values(NumArgs);
212 for (Function::const_arg_iterator A = F->arg_begin(), E = F->arg_end();
214 const unsigned ArgNo = A->getArgNo();
215 const Type *ArgTy = FTy->getParamType(ArgNo);
216 values[ArgNo] = ffiValueFor(ArgTy, ArgVals[ArgNo], ArgDataPtr);
217 ArgDataPtr += TD->getTypeStoreSize(ArgTy);
220 const Type *RetTy = FTy->getReturnType();
221 ffi_type *rtype = ffiTypeFor(RetTy);
223 if (ffi_prep_cif(&cif, FFI_DEFAULT_ABI, NumArgs, rtype, &args[0]) == FFI_OK) {
225 if (RetTy->getTypeID() != Type::VoidTyID)
226 ret = alloca(TD->getTypeStoreSize(RetTy));
227 ffi_call(&cif, Fn, ret, &values[0]);
228 switch (RetTy->getTypeID()) {
229 case Type::IntegerTyID:
230 switch (cast<IntegerType>(RetTy)->getBitWidth()) {
231 case 8: Result.IntVal = APInt(8 , *(int8_t *) ret); break;
232 case 16: Result.IntVal = APInt(16, *(int16_t*) ret); break;
233 case 32: Result.IntVal = APInt(32, *(int32_t*) ret); break;
234 case 64: Result.IntVal = APInt(64, *(int64_t*) ret); break;
237 case Type::FloatTyID: Result.FloatVal = *(float *) ret; break;
238 case Type::DoubleTyID: Result.DoubleVal = *(double*) ret; break;
239 case Type::PointerTyID: Result.PointerVal = *(void **) ret; break;
249 GenericValue Interpreter::callExternalFunction(Function *F,
250 const std::vector<GenericValue> &ArgVals) {
251 TheInterpreter = this;
253 FunctionsLock->acquire();
255 // Do a lookup to see if the function is in our cache... this should just be a
256 // deferred annotation!
257 std::map<const Function *, ExFunc>::iterator FI = ExportedFunctions->find(F);
258 if (ExFunc Fn = (FI == ExportedFunctions->end()) ? lookupFunction(F)
260 FunctionsLock->release();
261 return Fn(F->getFunctionType(), ArgVals);
265 std::map<const Function *, RawFunc>::iterator RF = RawFunctions->find(F);
267 if (RF == RawFunctions->end()) {
268 RawFn = (RawFunc)(intptr_t)
269 sys::DynamicLibrary::SearchForAddressOfSymbol(F->getName());
271 RawFunctions->insert(std::make_pair(F, RawFn)); // Cache for later
276 FunctionsLock->release();
279 if (RawFn != 0 && ffiInvoke(RawFn, F, ArgVals, getTargetData(), Result))
283 cerr << "Tried to execute an unknown external function: "
284 << F->getType()->getDescription() << " " << F->getName() << "\n";
285 if (F->getName() != "__main")
287 return GenericValue();
291 //===----------------------------------------------------------------------===//
292 // Functions "exported" to the running application...
294 extern "C" { // Don't add C++ manglings to llvm mangling :)
296 // void atexit(Function*)
297 GenericValue lle_X_atexit(const FunctionType *FT,
298 const std::vector<GenericValue> &Args) {
299 assert(Args.size() == 1);
300 TheInterpreter->addAtExitHandler((Function*)GVTOP(Args[0]));
307 GenericValue lle_X_exit(const FunctionType *FT,
308 const std::vector<GenericValue> &Args) {
309 TheInterpreter->exitCalled(Args[0]);
310 return GenericValue();
314 GenericValue lle_X_abort(const FunctionType *FT,
315 const std::vector<GenericValue> &Args) {
317 return GenericValue();
320 // int sprintf(char *, const char *, ...) - a very rough implementation to make
322 GenericValue lle_X_sprintf(const FunctionType *FT,
323 const std::vector<GenericValue> &Args) {
324 char *OutputBuffer = (char *)GVTOP(Args[0]);
325 const char *FmtStr = (const char *)GVTOP(Args[1]);
328 // printf should return # chars printed. This is completely incorrect, but
329 // close enough for now.
331 GV.IntVal = APInt(32, strlen(FmtStr));
334 case 0: return GV; // Null terminator...
335 default: // Normal nonspecial character
336 sprintf(OutputBuffer++, "%c", *FmtStr++);
338 case '\\': { // Handle escape codes
339 sprintf(OutputBuffer, "%c%c", *FmtStr, *(FmtStr+1));
340 FmtStr += 2; OutputBuffer += 2;
343 case '%': { // Handle format specifiers
344 char FmtBuf[100] = "", Buffer[1000] = "";
347 char Last = *FB++ = *FmtStr++;
348 unsigned HowLong = 0;
349 while (Last != 'c' && Last != 'd' && Last != 'i' && Last != 'u' &&
350 Last != 'o' && Last != 'x' && Last != 'X' && Last != 'e' &&
351 Last != 'E' && Last != 'g' && Last != 'G' && Last != 'f' &&
352 Last != 'p' && Last != 's' && Last != '%') {
353 if (Last == 'l' || Last == 'L') HowLong++; // Keep track of l's
354 Last = *FB++ = *FmtStr++;
360 strcpy(Buffer, "%"); break;
362 sprintf(Buffer, FmtBuf, uint32_t(Args[ArgNo++].IntVal.getZExtValue()));
369 TheInterpreter->getTargetData()->getPointerSizeInBits() == 64 &&
370 sizeof(long) < sizeof(int64_t)) {
371 // Make sure we use %lld with a 64 bit argument because we might be
372 // compiling LLI on a 32 bit compiler.
373 unsigned Size = strlen(FmtBuf);
374 FmtBuf[Size] = FmtBuf[Size-1];
376 FmtBuf[Size-1] = 'l';
378 sprintf(Buffer, FmtBuf, Args[ArgNo++].IntVal.getZExtValue());
380 sprintf(Buffer, FmtBuf,uint32_t(Args[ArgNo++].IntVal.getZExtValue()));
382 case 'e': case 'E': case 'g': case 'G': case 'f':
383 sprintf(Buffer, FmtBuf, Args[ArgNo++].DoubleVal); break;
385 sprintf(Buffer, FmtBuf, (void*)GVTOP(Args[ArgNo++])); break;
387 sprintf(Buffer, FmtBuf, (char*)GVTOP(Args[ArgNo++])); break;
388 default: cerr << "<unknown printf code '" << *FmtStr << "'!>";
391 strcpy(OutputBuffer, Buffer);
392 OutputBuffer += strlen(Buffer);
400 // int printf(const char *, ...) - a very rough implementation to make output
402 GenericValue lle_X_printf(const FunctionType *FT,
403 const std::vector<GenericValue> &Args) {
405 std::vector<GenericValue> NewArgs;
406 NewArgs.push_back(PTOGV((void*)&Buffer[0]));
407 NewArgs.insert(NewArgs.end(), Args.begin(), Args.end());
408 GenericValue GV = lle_X_sprintf(FT, NewArgs);
413 static void ByteswapSCANFResults(const char *Fmt, void *Arg0, void *Arg1,
414 void *Arg2, void *Arg3, void *Arg4, void *Arg5,
415 void *Arg6, void *Arg7, void *Arg8) {
416 void *Args[] = { Arg0, Arg1, Arg2, Arg3, Arg4, Arg5, Arg6, Arg7, Arg8, 0 };
418 // Loop over the format string, munging read values as appropriate (performs
419 // byteswaps as necessary).
423 // Read any flag characters that may be present...
424 bool Suppress = false;
427 bool LongLong = false; // long long or long double
431 case '*': Suppress = true; break;
432 case 'a': /*Allocate = true;*/ break; // We don't need to track this
433 case 'h': Half = true; break;
434 case 'l': Long = true; break;
436 case 'L': LongLong = true; break;
438 if (Fmt[-1] > '9' || Fmt[-1] < '0') // Ignore field width specs
444 // Read the conversion character
445 if (!Suppress && Fmt[-1] != '%') { // Nothing to do?
450 case 'i': case 'o': case 'u': case 'x': case 'X': case 'n': case 'p':
452 if (Long || LongLong) {
453 Size = 8; Ty = Type::Int64Ty;
455 Size = 4; Ty = Type::Int16Ty;
457 Size = 4; Ty = Type::Int32Ty;
461 case 'e': case 'g': case 'E':
463 if (Long || LongLong) {
464 Size = 8; Ty = Type::DoubleTy;
466 Size = 4; Ty = Type::FloatTy;
470 case 's': case 'c': case '[': // No byteswap needed
480 void *Arg = Args[ArgNo++];
481 memcpy(&GV, Arg, Size);
482 TheInterpreter->StoreValueToMemory(GV, (GenericValue*)Arg, Ty);
489 // int sscanf(const char *format, ...);
490 GenericValue lle_X_sscanf(const FunctionType *FT,
491 const std::vector<GenericValue> &args) {
492 assert(args.size() < 10 && "Only handle up to 10 args to sscanf right now!");
495 for (unsigned i = 0; i < args.size(); ++i)
496 Args[i] = (char*)GVTOP(args[i]);
499 GV.IntVal = APInt(32, sscanf(Args[0], Args[1], Args[2], Args[3], Args[4],
500 Args[5], Args[6], Args[7], Args[8], Args[9]));
501 ByteswapSCANFResults(Args[1], Args[2], Args[3], Args[4],
502 Args[5], Args[6], Args[7], Args[8], Args[9], 0);
506 // int scanf(const char *format, ...);
507 GenericValue lle_X_scanf(const FunctionType *FT,
508 const std::vector<GenericValue> &args) {
509 assert(args.size() < 10 && "Only handle up to 10 args to scanf right now!");
512 for (unsigned i = 0; i < args.size(); ++i)
513 Args[i] = (char*)GVTOP(args[i]);
516 GV.IntVal = APInt(32, scanf( Args[0], Args[1], Args[2], Args[3], Args[4],
517 Args[5], Args[6], Args[7], Args[8], Args[9]));
518 ByteswapSCANFResults(Args[0], Args[1], Args[2], Args[3], Args[4],
519 Args[5], Args[6], Args[7], Args[8], Args[9]);
523 // int fprintf(FILE *, const char *, ...) - a very rough implementation to make
525 GenericValue lle_X_fprintf(const FunctionType *FT,
526 const std::vector<GenericValue> &Args) {
527 assert(Args.size() >= 2);
529 std::vector<GenericValue> NewArgs;
530 NewArgs.push_back(PTOGV(Buffer));
531 NewArgs.insert(NewArgs.end(), Args.begin()+1, Args.end());
532 GenericValue GV = lle_X_sprintf(FT, NewArgs);
534 fputs(Buffer, (FILE *) GVTOP(Args[0]));
541 void Interpreter::initializeExternalFunctions() {
542 sys::ScopedLock Writer(&*FunctionsLock);
543 FuncNames["lle_X_atexit"] = lle_X_atexit;
544 FuncNames["lle_X_exit"] = lle_X_exit;
545 FuncNames["lle_X_abort"] = lle_X_abort;
547 FuncNames["lle_X_printf"] = lle_X_printf;
548 FuncNames["lle_X_sprintf"] = lle_X_sprintf;
549 FuncNames["lle_X_sscanf"] = lle_X_sscanf;
550 FuncNames["lle_X_scanf"] = lle_X_scanf;
551 FuncNames["lle_X_fprintf"] = lle_X_fprintf;