LLVM  3.7.0
ExternalFunctions.cpp
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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/Config/config.h" // Detect libffi
24 #include "llvm/IR/DataLayout.h"
25 #include "llvm/IR/DerivedTypes.h"
26 #include "llvm/IR/Module.h"
30 #include "llvm/Support/Mutex.h"
32 #include <cmath>
33 #include <csignal>
34 #include <cstdio>
35 #include <cstring>
36 #include <map>
37 
38 #ifdef HAVE_FFI_CALL
39 #ifdef HAVE_FFI_H
40 #include <ffi.h>
41 #define USE_LIBFFI
42 #elif HAVE_FFI_FFI_H
43 #include <ffi/ffi.h>
44 #define USE_LIBFFI
45 #endif
46 #endif
47 
48 using namespace llvm;
49 
51 
55 
56 #ifdef USE_LIBFFI
57 typedef void (*RawFunc)();
59 #endif
60 
62 
63 static char getTypeID(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  default: return 'U';
82  }
83 }
84 
85 // Try to find address of external function given a Function object.
86 // Please note, that interpreter doesn't know how to assemble a
87 // real call in general case (this is JIT job), that's why it assumes,
88 // that all external functions has the same (and pretty "general") signature.
89 // The typical example of such functions are "lle_X_" ones.
90 static ExFunc lookupFunction(const Function *F) {
91  // Function not found, look it up... start by figuring out what the
92  // composite function name should be.
93  std::string ExtName = "lle_";
94  FunctionType *FT = F->getFunctionType();
95  for (unsigned i = 0, e = FT->getNumContainedTypes(); i != e; ++i)
96  ExtName += getTypeID(FT->getContainedType(i));
97  ExtName += ("_" + F->getName()).str();
98 
100  ExFunc FnPtr = (*FuncNames)[ExtName];
101  if (!FnPtr)
102  FnPtr = (*FuncNames)[("lle_X_" + F->getName()).str()];
103  if (!FnPtr) // Try calling a generic function... if it exists...
105  ("lle_X_" + F->getName()).str());
106  if (FnPtr)
107  ExportedFunctions->insert(std::make_pair(F, FnPtr)); // Cache for later
108  return FnPtr;
109 }
110 
111 #ifdef USE_LIBFFI
112 static ffi_type *ffiTypeFor(Type *Ty) {
113  switch (Ty->getTypeID()) {
114  case Type::VoidTyID: return &ffi_type_void;
115  case Type::IntegerTyID:
116  switch (cast<IntegerType>(Ty)->getBitWidth()) {
117  case 8: return &ffi_type_sint8;
118  case 16: return &ffi_type_sint16;
119  case 32: return &ffi_type_sint32;
120  case 64: return &ffi_type_sint64;
121  }
122  case Type::FloatTyID: return &ffi_type_float;
123  case Type::DoubleTyID: return &ffi_type_double;
124  case Type::PointerTyID: return &ffi_type_pointer;
125  default: break;
126  }
127  // TODO: Support other types such as StructTyID, ArrayTyID, OpaqueTyID, etc.
128  report_fatal_error("Type could not be mapped for use with libffi.");
129  return NULL;
130 }
131 
132 static void *ffiValueFor(Type *Ty, const GenericValue &AV,
133  void *ArgDataPtr) {
134  switch (Ty->getTypeID()) {
135  case Type::IntegerTyID:
136  switch (cast<IntegerType>(Ty)->getBitWidth()) {
137  case 8: {
138  int8_t *I8Ptr = (int8_t *) ArgDataPtr;
139  *I8Ptr = (int8_t) AV.IntVal.getZExtValue();
140  return ArgDataPtr;
141  }
142  case 16: {
143  int16_t *I16Ptr = (int16_t *) ArgDataPtr;
144  *I16Ptr = (int16_t) AV.IntVal.getZExtValue();
145  return ArgDataPtr;
146  }
147  case 32: {
148  int32_t *I32Ptr = (int32_t *) ArgDataPtr;
149  *I32Ptr = (int32_t) AV.IntVal.getZExtValue();
150  return ArgDataPtr;
151  }
152  case 64: {
153  int64_t *I64Ptr = (int64_t *) ArgDataPtr;
154  *I64Ptr = (int64_t) AV.IntVal.getZExtValue();
155  return ArgDataPtr;
156  }
157  }
158  case Type::FloatTyID: {
159  float *FloatPtr = (float *) ArgDataPtr;
160  *FloatPtr = AV.FloatVal;
161  return ArgDataPtr;
162  }
163  case Type::DoubleTyID: {
164  double *DoublePtr = (double *) ArgDataPtr;
165  *DoublePtr = AV.DoubleVal;
166  return ArgDataPtr;
167  }
168  case Type::PointerTyID: {
169  void **PtrPtr = (void **) ArgDataPtr;
170  *PtrPtr = GVTOP(AV);
171  return ArgDataPtr;
172  }
173  default: break;
174  }
175  // TODO: Support other types such as StructTyID, ArrayTyID, OpaqueTyID, etc.
176  report_fatal_error("Type value could not be mapped for use with libffi.");
177  return NULL;
178 }
179 
180 static bool ffiInvoke(RawFunc Fn, Function *F, ArrayRef<GenericValue> ArgVals,
181  const DataLayout *TD, GenericValue &Result) {
182  ffi_cif cif;
183  FunctionType *FTy = F->getFunctionType();
184  const unsigned NumArgs = F->arg_size();
185 
186  // TODO: We don't have type information about the remaining arguments, because
187  // this information is never passed into ExecutionEngine::runFunction().
188  if (ArgVals.size() > NumArgs && F->isVarArg()) {
189  report_fatal_error("Calling external var arg function '" + F->getName()
190  + "' is not supported by the Interpreter.");
191  }
192 
193  unsigned ArgBytes = 0;
194 
195  std::vector<ffi_type*> args(NumArgs);
196  for (Function::const_arg_iterator A = F->arg_begin(), E = F->arg_end();
197  A != E; ++A) {
198  const unsigned ArgNo = A->getArgNo();
199  Type *ArgTy = FTy->getParamType(ArgNo);
200  args[ArgNo] = ffiTypeFor(ArgTy);
201  ArgBytes += TD->getTypeStoreSize(ArgTy);
202  }
203 
205  ArgData.resize(ArgBytes);
206  uint8_t *ArgDataPtr = ArgData.data();
208  for (Function::const_arg_iterator A = F->arg_begin(), E = F->arg_end();
209  A != E; ++A) {
210  const unsigned ArgNo = A->getArgNo();
211  Type *ArgTy = FTy->getParamType(ArgNo);
212  values[ArgNo] = ffiValueFor(ArgTy, ArgVals[ArgNo], ArgDataPtr);
213  ArgDataPtr += TD->getTypeStoreSize(ArgTy);
214  }
215 
216  Type *RetTy = FTy->getReturnType();
217  ffi_type *rtype = ffiTypeFor(RetTy);
218 
219  if (ffi_prep_cif(&cif, FFI_DEFAULT_ABI, NumArgs, rtype, &args[0]) == FFI_OK) {
221  if (RetTy->getTypeID() != Type::VoidTyID)
222  ret.resize(TD->getTypeStoreSize(RetTy));
223  ffi_call(&cif, Fn, ret.data(), values.data());
224  switch (RetTy->getTypeID()) {
225  case Type::IntegerTyID:
226  switch (cast<IntegerType>(RetTy)->getBitWidth()) {
227  case 8: Result.IntVal = APInt(8 , *(int8_t *) ret.data()); break;
228  case 16: Result.IntVal = APInt(16, *(int16_t*) ret.data()); break;
229  case 32: Result.IntVal = APInt(32, *(int32_t*) ret.data()); break;
230  case 64: Result.IntVal = APInt(64, *(int64_t*) ret.data()); break;
231  }
232  break;
233  case Type::FloatTyID: Result.FloatVal = *(float *) ret.data(); break;
234  case Type::DoubleTyID: Result.DoubleVal = *(double*) ret.data(); break;
235  case Type::PointerTyID: Result.PointerVal = *(void **) ret.data(); break;
236  default: break;
237  }
238  return true;
239  }
240 
241  return false;
242 }
243 #endif // USE_LIBFFI
244 
246  ArrayRef<GenericValue> ArgVals) {
247  TheInterpreter = this;
248 
250 
251  // Do a lookup to see if the function is in our cache... this should just be a
252  // deferred annotation!
253  std::map<const Function *, ExFunc>::iterator FI = ExportedFunctions->find(F);
254  if (ExFunc Fn = (FI == ExportedFunctions->end()) ? lookupFunction(F)
255  : FI->second) {
256  Guard.unlock();
257  return Fn(F->getFunctionType(), ArgVals);
258  }
259 
260 #ifdef USE_LIBFFI
261  std::map<const Function *, RawFunc>::iterator RF = RawFunctions->find(F);
262  RawFunc RawFn;
263  if (RF == RawFunctions->end()) {
264  RawFn = (RawFunc)(intptr_t)
266  if (!RawFn)
267  RawFn = (RawFunc)(intptr_t)getPointerToGlobalIfAvailable(F);
268  if (RawFn != 0)
269  RawFunctions->insert(std::make_pair(F, RawFn)); // Cache for later
270  } else {
271  RawFn = RF->second;
272  }
273 
274  Guard.unlock();
275 
276  GenericValue Result;
277  if (RawFn != 0 && ffiInvoke(RawFn, F, ArgVals, getDataLayout(), 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() << " __main\n";
284  else
285  report_fatal_error("Tried to execute an unknown external function: " +
286  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 // void atexit(Function*)
300  ArrayRef<GenericValue> Args) {
301  assert(Args.size() == 1);
303  GenericValue GV;
304  GV.IntVal = 0;
305  return GV;
306 }
307 
308 // void exit(int)
310  TheInterpreter->exitCalled(Args[0]);
311  return GenericValue();
312 }
313 
314 // void abort(void)
316  //FIXME: should we report or raise here?
317  //report_fatal_error("Interpreted program raised SIGABRT");
318  raise (SIGABRT);
319  return GenericValue();
320 }
321 
322 // int sprintf(char *, const char *, ...) - a very rough implementation to make
323 // output useful.
325  ArrayRef<GenericValue> Args) {
326  char *OutputBuffer = (char *)GVTOP(Args[0]);
327  const char *FmtStr = (const char *)GVTOP(Args[1]);
328  unsigned ArgNo = 2;
329 
330  // printf should return # chars printed. This is completely incorrect, but
331  // close enough for now.
332  GenericValue GV;
333  GV.IntVal = APInt(32, strlen(FmtStr));
334  while (1) {
335  switch (*FmtStr) {
336  case 0: return GV; // Null terminator...
337  default: // Normal nonspecial character
338  sprintf(OutputBuffer++, "%c", *FmtStr++);
339  break;
340  case '\\': { // Handle escape codes
341  sprintf(OutputBuffer, "%c%c", *FmtStr, *(FmtStr+1));
342  FmtStr += 2; OutputBuffer += 2;
343  break;
344  }
345  case '%': { // Handle format specifiers
346  char FmtBuf[100] = "", Buffer[1000] = "";
347  char *FB = FmtBuf;
348  *FB++ = *FmtStr++;
349  char Last = *FB++ = *FmtStr++;
350  unsigned HowLong = 0;
351  while (Last != 'c' && Last != 'd' && Last != 'i' && Last != 'u' &&
352  Last != 'o' && Last != 'x' && Last != 'X' && Last != 'e' &&
353  Last != 'E' && Last != 'g' && Last != 'G' && Last != 'f' &&
354  Last != 'p' && Last != 's' && Last != '%') {
355  if (Last == 'l' || Last == 'L') HowLong++; // Keep track of l's
356  Last = *FB++ = *FmtStr++;
357  }
358  *FB = 0;
359 
360  switch (Last) {
361  case '%':
362  memcpy(Buffer, "%", 2); break;
363  case 'c':
364  sprintf(Buffer, FmtBuf, uint32_t(Args[ArgNo++].IntVal.getZExtValue()));
365  break;
366  case 'd': case 'i':
367  case 'u': case 'o':
368  case 'x': case 'X':
369  if (HowLong >= 1) {
370  if (HowLong == 1 &&
372  sizeof(long) < sizeof(int64_t)) {
373  // Make sure we use %lld with a 64 bit argument because we might be
374  // compiling LLI on a 32 bit compiler.
375  unsigned Size = strlen(FmtBuf);
376  FmtBuf[Size] = FmtBuf[Size-1];
377  FmtBuf[Size+1] = 0;
378  FmtBuf[Size-1] = 'l';
379  }
380  sprintf(Buffer, FmtBuf, Args[ArgNo++].IntVal.getZExtValue());
381  } else
382  sprintf(Buffer, FmtBuf,uint32_t(Args[ArgNo++].IntVal.getZExtValue()));
383  break;
384  case 'e': case 'E': case 'g': case 'G': case 'f':
385  sprintf(Buffer, FmtBuf, Args[ArgNo++].DoubleVal); break;
386  case 'p':
387  sprintf(Buffer, FmtBuf, (void*)GVTOP(Args[ArgNo++])); break;
388  case 's':
389  sprintf(Buffer, FmtBuf, (char*)GVTOP(Args[ArgNo++])); break;
390  default:
391  errs() << "<unknown printf code '" << *FmtStr << "'!>";
392  ArgNo++; break;
393  }
394  size_t Len = strlen(Buffer);
395  memcpy(OutputBuffer, Buffer, Len + 1);
396  OutputBuffer += Len;
397  }
398  break;
399  }
400  }
401  return GV;
402 }
403 
404 // int printf(const char *, ...) - a very rough implementation to make output
405 // useful.
407  ArrayRef<GenericValue> Args) {
408  char Buffer[10000];
409  std::vector<GenericValue> NewArgs;
410  NewArgs.push_back(PTOGV((void*)&Buffer[0]));
411  NewArgs.insert(NewArgs.end(), Args.begin(), Args.end());
412  GenericValue GV = lle_X_sprintf(FT, NewArgs);
413  outs() << Buffer;
414  return GV;
415 }
416 
417 // int sscanf(const char *format, ...);
419  ArrayRef<GenericValue> args) {
420  assert(args.size() < 10 && "Only handle up to 10 args to sscanf right now!");
421 
422  char *Args[10];
423  for (unsigned i = 0; i < args.size(); ++i)
424  Args[i] = (char*)GVTOP(args[i]);
425 
426  GenericValue GV;
427  GV.IntVal = APInt(32, sscanf(Args[0], Args[1], Args[2], Args[3], Args[4],
428  Args[5], Args[6], Args[7], Args[8], Args[9]));
429  return GV;
430 }
431 
432 // int scanf(const char *format, ...);
434  assert(args.size() < 10 && "Only handle up to 10 args to scanf right now!");
435 
436  char *Args[10];
437  for (unsigned i = 0; i < args.size(); ++i)
438  Args[i] = (char*)GVTOP(args[i]);
439 
440  GenericValue GV;
441  GV.IntVal = APInt(32, scanf( Args[0], Args[1], Args[2], Args[3], Args[4],
442  Args[5], Args[6], Args[7], Args[8], Args[9]));
443  return GV;
444 }
445 
446 // int fprintf(FILE *, const char *, ...) - a very rough implementation to make
447 // output useful.
449  ArrayRef<GenericValue> Args) {
450  assert(Args.size() >= 2);
451  char Buffer[10000];
452  std::vector<GenericValue> NewArgs;
453  NewArgs.push_back(PTOGV(Buffer));
454  NewArgs.insert(NewArgs.end(), Args.begin()+1, Args.end());
455  GenericValue GV = lle_X_sprintf(FT, NewArgs);
456 
457  fputs(Buffer, (FILE *) GVTOP(Args[0]));
458  return GV;
459 }
460 
462  ArrayRef<GenericValue> Args) {
463  int val = (int)Args[1].IntVal.getSExtValue();
464  size_t len = (size_t)Args[2].IntVal.getZExtValue();
465  memset((void *)GVTOP(Args[0]), val, len);
466  // llvm.memset.* returns void, lle_X_* returns GenericValue,
467  // so here we return GenericValue with IntVal set to zero
468  GenericValue GV;
469  GV.IntVal = 0;
470  return GV;
471 }
472 
474  ArrayRef<GenericValue> Args) {
475  memcpy(GVTOP(Args[0]), GVTOP(Args[1]),
476  (size_t)(Args[2].IntVal.getLimitedValue()));
477 
478  // llvm.memcpy* returns void, lle_X_* returns GenericValue,
479  // so here we return GenericValue with IntVal set to zero
480  GenericValue GV;
481  GV.IntVal = 0;
482  return GV;
483 }
484 
485 void Interpreter::initializeExternalFunctions() {
487  (*FuncNames)["lle_X_atexit"] = lle_X_atexit;
488  (*FuncNames)["lle_X_exit"] = lle_X_exit;
489  (*FuncNames)["lle_X_abort"] = lle_X_abort;
490 
491  (*FuncNames)["lle_X_printf"] = lle_X_printf;
492  (*FuncNames)["lle_X_sprintf"] = lle_X_sprintf;
493  (*FuncNames)["lle_X_sscanf"] = lle_X_sscanf;
494  (*FuncNames)["lle_X_scanf"] = lle_X_scanf;
495  (*FuncNames)["lle_X_fprintf"] = lle_X_fprintf;
496  (*FuncNames)["lle_X_memset"] = lle_X_memset;
497  (*FuncNames)["lle_X_memcpy"] = lle_X_memcpy;
498 }
ValuesClass< DataType > LLVM_END_WITH_NULL values(const char *Arg, DataType Val, const char *Desc,...)
Definition: CommandLine.h:536
A parsed version of the target data layout string in and methods for querying it. ...
Definition: DataLayout.h:104
PointerTy PointerVal
Definition: GenericValue.h:34
static void * SearchForAddressOfSymbol(const char *symbolName)
This function will search through all previously loaded dynamic libraries for the symbol symbolName...
raw_ostream & errs()
This returns a reference to a raw_ostream for standard error.
uint64_t getZExtValue() const
Get zero extended value.
Definition: APInt.h:1327
static Interpreter * TheInterpreter
static GenericValue lle_X_atexit(FunctionType *FT, ArrayRef< GenericValue > Args)
2: 32-bit floating point type
Definition: Type.h:58
void * getPointerToGlobalIfAvailable(StringRef S)
getPointerToGlobalIfAvailable - This returns the address of the specified global value if it is has a...
static GenericValue lle_X_exit(FunctionType *FT, ArrayRef< GenericValue > Args)
iterator end() const
Definition: ArrayRef.h:123
arg_iterator arg_end()
Definition: Function.h:480
12: Structures
Definition: Type.h:71
F(f)
static GenericValue lle_X_sprintf(FunctionType *FT, ArrayRef< GenericValue > Args)
14: Pointers
Definition: Type.h:73
11: Functions
Definition: Type.h:70
LLVM_ATTRIBUTE_NORETURN void report_fatal_error(const char *reason, bool gen_crash_diag=true)
Reports a serious error, calling any installed error handler.
static ExFunc lookupFunction(const Function *F)
size_t arg_size() const
Definition: Function.cpp:301
StringRef getName() const
Return a constant reference to the value's name.
Definition: Value.cpp:188
static GenericValue lle_X_sscanf(FunctionType *FT, ArrayRef< GenericValue > args)
FunctionType - Class to represent function types.
Definition: DerivedTypes.h:96
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory)...
Definition: ArrayRef.h:31
TypeID getTypeID() const
getTypeID - Return the type id for the type.
Definition: Type.h:134
size_t size() const
size - Get the array size.
Definition: ArrayRef.h:134
10: Arbitrary bit width integers
Definition: Type.h:69
raw_ostream & outs()
This returns a reference to a raw_ostream for standard output.
0: type with no size
Definition: Type.h:56
static ManagedStatic< sys::Mutex > FunctionsLock
Type * getParamType(unsigned i) const
Parameter type accessors.
Definition: DerivedTypes.h:131
static GenericValue lle_X_memcpy(FunctionType *FT, ArrayRef< GenericValue > Args)
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:45
static ManagedStatic< std::map< const Function *, ExFunc > > ExportedFunctions
Type * getContainedType(unsigned i) const
getContainedType - This method is used to implement the type iterator (defined at the end of the file...
Definition: Type.h:332
static ManagedStatic< std::map< std::string, ExFunc > > FuncNames
A pared-down imitation of std::unique_lock from C++11.
Definition: UniqueLock.h:28
void exitCalled(GenericValue GV)
Definition: Execution.cpp:820
iterator begin() const
Definition: ArrayRef.h:122
arg_iterator arg_begin()
Definition: Function.h:472
static GenericValue lle_X_abort(FunctionType *FT, ArrayRef< GenericValue > Args)
unsigned getNumContainedTypes() const
getNumContainedTypes - Return the number of types in the derived type.
Definition: Type.h:339
GenericValue(* ExFunc)(FunctionType *, ArrayRef< GenericValue >)
void * GVTOP(const GenericValue &GV)
Definition: GenericValue.h:50
13: Arrays
Definition: Type.h:72
This is a 'vector' (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:861
Module.h This file contains the declarations for the Module class.
static GenericValue lle_X_fprintf(FunctionType *FT, ArrayRef< GenericValue > Args)
GenericValue PTOGV(void *P)
Definition: GenericValue.h:49
Class for arbitrary precision integers.
Definition: APInt.h:73
static char getTypeID(Type *Ty)
PointerType * getType() const
Global values are always pointers.
Definition: GlobalValue.h:185
pointer data()
Return a pointer to the vector's buffer, even if empty().
Definition: SmallVector.h:134
const DataLayout * getDataLayout() const
FunctionType * getFunctionType() const
Definition: Function.cpp:227
unsigned getPointerSizeInBits(unsigned AS=0) const
Layout pointer size, in bits FIXME: The defaults need to be removed once all of the backends/clients ...
Definition: DataLayout.h:329
uint64_t getTypeStoreSize(Type *Ty) const
Returns the maximum number of bytes that may be overwritten by storing the specified type...
Definition: DataLayout.h:371
3: 64-bit floating point type
Definition: Type.h:59
Type * getReturnType() const
Definition: DerivedTypes.h:121
static GenericValue lle_X_memset(FunctionType *FT, ArrayRef< GenericValue > Args)
static GenericValue lle_X_printf(FunctionType *FT, ArrayRef< GenericValue > Args)
GenericValue callExternalFunction(Function *F, ArrayRef< GenericValue > ArgVals)
static GenericValue lle_X_scanf(FunctionType *FT, ArrayRef< GenericValue > args)
ManagedStatic - This transparently changes the behavior of global statics to be lazily constructed on...
Definition: ManagedStatic.h:61
bool isVarArg() const
isVarArg - Return true if this function takes a variable number of arguments.
Definition: Function.cpp:229
void resize(size_type N)
Definition: SmallVector.h:376