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"
42 typedef GenericValue (*ExFunc)(const FunctionType *,
43 const std::vector<GenericValue> &);
44 static ManagedStatic<std::map<const Function *, ExFunc> > ExportedFunctions;
45 static std::map<std::string, ExFunc> FuncNames;
48 typedef void (*RawFunc)(void);
49 static ManagedStatic<std::map<const Function *, RawFunc> > RawFunctions;
52 static Interpreter *TheInterpreter;
54 static char getTypeID(const Type *Ty) {
55 switch (Ty->getTypeID()) {
56 case Type::VoidTyID: return 'V';
57 case Type::IntegerTyID:
58 switch (cast<IntegerType>(Ty)->getBitWidth()) {
66 case Type::FloatTyID: return 'F';
67 case Type::DoubleTyID: return 'D';
68 case Type::PointerTyID: return 'P';
69 case Type::FunctionTyID:return 'M';
70 case Type::StructTyID: return 'T';
71 case Type::ArrayTyID: return 'A';
72 case Type::OpaqueTyID: return 'O';
77 // Try to find address of external function given a Function object.
78 // Please note, that interpreter doesn't know how to assemble a
79 // real call in general case (this is JIT job), that's why it assumes,
80 // that all external functions has the same (and pretty "general") signature.
81 // The typical example of such functions are "lle_X_" ones.
82 static ExFunc lookupFunction(const Function *F) {
83 // Function not found, look it up... start by figuring out what the
84 // composite function name should be.
85 std::string ExtName = "lle_";
86 const FunctionType *FT = F->getFunctionType();
87 for (unsigned i = 0, e = FT->getNumContainedTypes(); i != e; ++i)
88 ExtName += getTypeID(FT->getContainedType(i));
89 ExtName += "_" + F->getName();
91 ExFunc FnPtr = FuncNames[ExtName];
93 FnPtr = FuncNames["lle_X_"+F->getName()];
94 if (FnPtr == 0) // Try calling a generic function... if it exists...
95 FnPtr = (ExFunc)(intptr_t)sys::DynamicLibrary::SearchForAddressOfSymbol(
96 ("lle_X_"+F->getName()).c_str());
98 ExportedFunctions->insert(std::make_pair(F, FnPtr)); // Cache for later
103 static ffi_type *ffiTypeFor(const Type *Ty) {
104 switch (Ty->getTypeID()) {
105 case Type::VoidTyID: return &ffi_type_void;
106 case Type::IntegerTyID:
107 switch (cast<IntegerType>(Ty)->getBitWidth()) {
108 case 8: return &ffi_type_sint8;
109 case 16: return &ffi_type_sint16;
110 case 32: return &ffi_type_sint32;
111 case 64: return &ffi_type_sint64;
113 case Type::FloatTyID: return &ffi_type_float;
114 case Type::DoubleTyID: return &ffi_type_double;
115 case Type::PointerTyID: return &ffi_type_pointer;
118 // TODO: Support other types such as StructTyID, ArrayTyID, OpaqueTyID, etc.
119 cerr << "Type could not be mapped for use with libffi.\n";
124 static void *ffiValueFor(const Type *Ty, const GenericValue &AV,
126 switch (Ty->getTypeID()) {
127 case Type::IntegerTyID:
128 switch (cast<IntegerType>(Ty)->getBitWidth()) {
130 int8_t *I8Ptr = (int8_t *) ArgDataPtr;
131 *I8Ptr = (int8_t) AV.IntVal.getZExtValue();
135 int16_t *I16Ptr = (int16_t *) ArgDataPtr;
136 *I16Ptr = (int16_t) AV.IntVal.getZExtValue();
140 int32_t *I32Ptr = (int32_t *) ArgDataPtr;
141 *I32Ptr = (int32_t) AV.IntVal.getZExtValue();
145 int64_t *I64Ptr = (int64_t *) ArgDataPtr;
146 *I64Ptr = (int64_t) AV.IntVal.getZExtValue();
150 case Type::FloatTyID: {
151 float *FloatPtr = (float *) ArgDataPtr;
152 *FloatPtr = AV.FloatVal;
155 case Type::DoubleTyID: {
156 double *DoublePtr = (double *) ArgDataPtr;
157 *DoublePtr = AV.DoubleVal;
160 case Type::PointerTyID: {
161 void **PtrPtr = (void **) ArgDataPtr;
167 // TODO: Support other types such as StructTyID, ArrayTyID, OpaqueTyID, etc.
168 cerr << "Type value could not be mapped for use with libffi.\n";
173 static bool ffiInvoke(RawFunc Fn, Function *F,
174 const std::vector<GenericValue> &ArgVals,
175 const TargetData *TD, GenericValue &Result) {
177 const FunctionType *FTy = F->getFunctionType();
178 const unsigned NumArgs = F->arg_size();
180 // TODO: We don't have type information about the remaining arguments, because
181 // this information is never passed into ExecutionEngine::runFunction().
182 if (ArgVals.size() > NumArgs && F->isVarArg()) {
183 cerr << "Calling external var arg function '" << F->getName()
184 << "' is not supported by the Interpreter.\n";
188 unsigned ArgBytes = 0;
190 std::vector<ffi_type*> args(NumArgs);
191 for (Function::const_arg_iterator A = F->arg_begin(), E = F->arg_end();
193 const unsigned ArgNo = A->getArgNo();
194 const Type *ArgTy = FTy->getParamType(ArgNo);
195 args[ArgNo] = ffiTypeFor(ArgTy);
196 ArgBytes += TD->getTypeStoreSize(ArgTy);
199 uint8_t *ArgData = (uint8_t*) alloca(ArgBytes);
200 uint8_t *ArgDataPtr = ArgData;
201 std::vector<void*> values(NumArgs);
202 for (Function::const_arg_iterator A = F->arg_begin(), E = F->arg_end();
204 const unsigned ArgNo = A->getArgNo();
205 const Type *ArgTy = FTy->getParamType(ArgNo);
206 values[ArgNo] = ffiValueFor(ArgTy, ArgVals[ArgNo], ArgDataPtr);
207 ArgDataPtr += TD->getTypeStoreSize(ArgTy);
210 const Type *RetTy = FTy->getReturnType();
211 ffi_type *rtype = ffiTypeFor(RetTy);
213 if (ffi_prep_cif(&cif, FFI_DEFAULT_ABI, NumArgs, rtype, &args[0]) == FFI_OK) {
215 if (RetTy->getTypeID() != Type::VoidTyID)
216 ret = alloca(TD->getTypeStoreSize(RetTy));
217 ffi_call(&cif, Fn, ret, &values[0]);
218 switch (RetTy->getTypeID()) {
219 case Type::IntegerTyID:
220 switch (cast<IntegerType>(RetTy)->getBitWidth()) {
221 case 8: Result.IntVal = APInt(8 , *(int8_t *) ret); break;
222 case 16: Result.IntVal = APInt(16, *(int16_t*) ret); break;
223 case 32: Result.IntVal = APInt(32, *(int32_t*) ret); break;
224 case 64: Result.IntVal = APInt(64, *(int64_t*) ret); break;
227 case Type::FloatTyID: Result.FloatVal = *(float *) ret; break;
228 case Type::DoubleTyID: Result.DoubleVal = *(double*) ret; break;
229 case Type::PointerTyID: Result.PointerVal = *(void **) ret; break;
237 #endif // HAVE_LIBFFI
239 GenericValue Interpreter::callExternalFunction(Function *F,
240 const std::vector<GenericValue> &ArgVals) {
241 TheInterpreter = this;
243 // Do a lookup to see if the function is in our cache... this should just be a
244 // deferred annotation!
245 std::map<const Function *, ExFunc>::iterator FI = ExportedFunctions->find(F);
246 if (ExFunc Fn = (FI == ExportedFunctions->end()) ? lookupFunction(F)
248 return Fn(F->getFunctionType(), ArgVals);
251 std::map<const Function *, RawFunc>::iterator RF = RawFunctions->find(F);
253 if (RF == RawFunctions->end()) {
254 RawFn = (RawFunc)(intptr_t)
255 sys::DynamicLibrary::SearchForAddressOfSymbol(F->getName());
257 RawFunctions->insert(std::make_pair(F, RawFn)); // Cache for later
263 if (RawFn != 0 && ffiInvoke(RawFn, F, ArgVals, getTargetData(), Result))
265 #endif // HAVE_LIBFFI
267 cerr << "Tried to execute an unknown external function: "
268 << F->getType()->getDescription() << " " << F->getName() << "\n";
269 if (F->getName() != "__main")
271 return GenericValue();
275 //===----------------------------------------------------------------------===//
276 // Functions "exported" to the running application...
278 extern "C" { // Don't add C++ manglings to llvm mangling :)
280 // void atexit(Function*)
281 GenericValue lle_X_atexit(const FunctionType *FT,
282 const std::vector<GenericValue> &Args) {
283 assert(Args.size() == 1);
284 TheInterpreter->addAtExitHandler((Function*)GVTOP(Args[0]));
291 GenericValue lle_X_exit(const FunctionType *FT,
292 const std::vector<GenericValue> &Args) {
293 TheInterpreter->exitCalled(Args[0]);
294 return GenericValue();
298 GenericValue lle_X_abort(const FunctionType *FT,
299 const std::vector<GenericValue> &Args) {
301 return GenericValue();
304 // int sprintf(char *, const char *, ...) - a very rough implementation to make
306 GenericValue lle_X_sprintf(const FunctionType *FT,
307 const std::vector<GenericValue> &Args) {
308 char *OutputBuffer = (char *)GVTOP(Args[0]);
309 const char *FmtStr = (const char *)GVTOP(Args[1]);
312 // printf should return # chars printed. This is completely incorrect, but
313 // close enough for now.
315 GV.IntVal = APInt(32, strlen(FmtStr));
318 case 0: return GV; // Null terminator...
319 default: // Normal nonspecial character
320 sprintf(OutputBuffer++, "%c", *FmtStr++);
322 case '\\': { // Handle escape codes
323 sprintf(OutputBuffer, "%c%c", *FmtStr, *(FmtStr+1));
324 FmtStr += 2; OutputBuffer += 2;
327 case '%': { // Handle format specifiers
328 char FmtBuf[100] = "", Buffer[1000] = "";
331 char Last = *FB++ = *FmtStr++;
332 unsigned HowLong = 0;
333 while (Last != 'c' && Last != 'd' && Last != 'i' && Last != 'u' &&
334 Last != 'o' && Last != 'x' && Last != 'X' && Last != 'e' &&
335 Last != 'E' && Last != 'g' && Last != 'G' && Last != 'f' &&
336 Last != 'p' && Last != 's' && Last != '%') {
337 if (Last == 'l' || Last == 'L') HowLong++; // Keep track of l's
338 Last = *FB++ = *FmtStr++;
344 strcpy(Buffer, "%"); break;
346 sprintf(Buffer, FmtBuf, uint32_t(Args[ArgNo++].IntVal.getZExtValue()));
353 TheInterpreter->getTargetData()->getPointerSizeInBits() == 64 &&
354 sizeof(long) < sizeof(int64_t)) {
355 // Make sure we use %lld with a 64 bit argument because we might be
356 // compiling LLI on a 32 bit compiler.
357 unsigned Size = strlen(FmtBuf);
358 FmtBuf[Size] = FmtBuf[Size-1];
360 FmtBuf[Size-1] = 'l';
362 sprintf(Buffer, FmtBuf, Args[ArgNo++].IntVal.getZExtValue());
364 sprintf(Buffer, FmtBuf,uint32_t(Args[ArgNo++].IntVal.getZExtValue()));
366 case 'e': case 'E': case 'g': case 'G': case 'f':
367 sprintf(Buffer, FmtBuf, Args[ArgNo++].DoubleVal); break;
369 sprintf(Buffer, FmtBuf, (void*)GVTOP(Args[ArgNo++])); break;
371 sprintf(Buffer, FmtBuf, (char*)GVTOP(Args[ArgNo++])); break;
372 default: cerr << "<unknown printf code '" << *FmtStr << "'!>";
375 strcpy(OutputBuffer, Buffer);
376 OutputBuffer += strlen(Buffer);
384 // int printf(const char *, ...) - a very rough implementation to make output
386 GenericValue lle_X_printf(const FunctionType *FT,
387 const std::vector<GenericValue> &Args) {
389 std::vector<GenericValue> NewArgs;
390 NewArgs.push_back(PTOGV((void*)&Buffer[0]));
391 NewArgs.insert(NewArgs.end(), Args.begin(), Args.end());
392 GenericValue GV = lle_X_sprintf(FT, NewArgs);
397 static void ByteswapSCANFResults(const char *Fmt, void *Arg0, void *Arg1,
398 void *Arg2, void *Arg3, void *Arg4, void *Arg5,
399 void *Arg6, void *Arg7, void *Arg8) {
400 void *Args[] = { Arg0, Arg1, Arg2, Arg3, Arg4, Arg5, Arg6, Arg7, Arg8, 0 };
402 // Loop over the format string, munging read values as appropriate (performs
403 // byteswaps as necessary).
407 // Read any flag characters that may be present...
408 bool Suppress = false;
411 bool LongLong = false; // long long or long double
415 case '*': Suppress = true; break;
416 case 'a': /*Allocate = true;*/ break; // We don't need to track this
417 case 'h': Half = true; break;
418 case 'l': Long = true; break;
420 case 'L': LongLong = true; break;
422 if (Fmt[-1] > '9' || Fmt[-1] < '0') // Ignore field width specs
428 // Read the conversion character
429 if (!Suppress && Fmt[-1] != '%') { // Nothing to do?
434 case 'i': case 'o': case 'u': case 'x': case 'X': case 'n': case 'p':
436 if (Long || LongLong) {
437 Size = 8; Ty = Type::Int64Ty;
439 Size = 4; Ty = Type::Int16Ty;
441 Size = 4; Ty = Type::Int32Ty;
445 case 'e': case 'g': case 'E':
447 if (Long || LongLong) {
448 Size = 8; Ty = Type::DoubleTy;
450 Size = 4; Ty = Type::FloatTy;
454 case 's': case 'c': case '[': // No byteswap needed
464 void *Arg = Args[ArgNo++];
465 memcpy(&GV, Arg, Size);
466 TheInterpreter->StoreValueToMemory(GV, (GenericValue*)Arg, Ty);
473 // int sscanf(const char *format, ...);
474 GenericValue lle_X_sscanf(const FunctionType *FT,
475 const std::vector<GenericValue> &args) {
476 assert(args.size() < 10 && "Only handle up to 10 args to sscanf right now!");
479 for (unsigned i = 0; i < args.size(); ++i)
480 Args[i] = (char*)GVTOP(args[i]);
483 GV.IntVal = APInt(32, sscanf(Args[0], Args[1], Args[2], Args[3], Args[4],
484 Args[5], Args[6], Args[7], Args[8], Args[9]));
485 ByteswapSCANFResults(Args[1], Args[2], Args[3], Args[4],
486 Args[5], Args[6], Args[7], Args[8], Args[9], 0);
490 // int scanf(const char *format, ...);
491 GenericValue lle_X_scanf(const FunctionType *FT,
492 const std::vector<GenericValue> &args) {
493 assert(args.size() < 10 && "Only handle up to 10 args to scanf right now!");
496 for (unsigned i = 0; i < args.size(); ++i)
497 Args[i] = (char*)GVTOP(args[i]);
500 GV.IntVal = APInt(32, scanf( Args[0], Args[1], Args[2], Args[3], Args[4],
501 Args[5], Args[6], Args[7], Args[8], Args[9]));
502 ByteswapSCANFResults(Args[0], Args[1], Args[2], Args[3], Args[4],
503 Args[5], Args[6], Args[7], Args[8], Args[9]);
507 // int fprintf(FILE *, const char *, ...) - a very rough implementation to make
509 GenericValue lle_X_fprintf(const FunctionType *FT,
510 const std::vector<GenericValue> &Args) {
511 assert(Args.size() >= 2);
513 std::vector<GenericValue> NewArgs;
514 NewArgs.push_back(PTOGV(Buffer));
515 NewArgs.insert(NewArgs.end(), Args.begin()+1, Args.end());
516 GenericValue GV = lle_X_sprintf(FT, NewArgs);
518 fputs(Buffer, (FILE *) GVTOP(Args[0]));
525 void Interpreter::initializeExternalFunctions() {
526 FuncNames["lle_X_atexit"] = lle_X_atexit;
527 FuncNames["lle_X_exit"] = lle_X_exit;
528 FuncNames["lle_X_abort"] = lle_X_abort;
530 FuncNames["lle_X_printf"] = lle_X_printf;
531 FuncNames["lle_X_sprintf"] = lle_X_sprintf;
532 FuncNames["lle_X_sscanf"] = lle_X_sscanf;
533 FuncNames["lle_X_scanf"] = lle_X_scanf;
534 FuncNames["lle_X_fprintf"] = lle_X_fprintf;