summaryrefslogtreecommitdiff
path: root/lib/ExecutionEngine/Interpreter/ExternalFunctions.cpp
blob: 0d8cae2fea1c13019cb43dc464a6fc0e15a148a5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
//===-- ExternalFunctions.cpp - Implement External Functions --------------===//
// 
//  This file contains both code to deal with invoking "external" functions, but
//  also contains code that implements "exported" external functions.
//
//  External functions in LLI are implemented by dlopen'ing the lli executable
//  and using dlsym to look op the functions that we want to invoke.  If a
//  function is found, then the arguments are mangled and passed in to the
//  function call.
//
//===----------------------------------------------------------------------===//

#include "Interpreter.h"
#include "ExecutionAnnotations.h"
#include "llvm/Module.h"
#include "llvm/DerivedTypes.h"
#include "llvm/SymbolTable.h"
#include "llvm/Target/TargetData.h"
#include <map>
#include <dlfcn.h>
#include <link.h>
#include <math.h>
#include <stdio.h>
using std::vector;
using std::cout;

typedef GenericValue (*ExFunc)(FunctionType *, const vector<GenericValue> &);
static std::map<const Function *, ExFunc> Functions;
static std::map<std::string, ExFunc> FuncNames;

static Interpreter *TheInterpreter;

// getCurrentExecutablePath() - Return the directory that the lli executable
// lives in.
//
std::string Interpreter::getCurrentExecutablePath() const {
  Dl_info Info;
  if (dladdr(&TheInterpreter, &Info) == 0) return "";
  
  std::string LinkAddr(Info.dli_fname);
  unsigned SlashPos = LinkAddr.rfind('/');
  if (SlashPos != std::string::npos)
    LinkAddr.resize(SlashPos);    // Trim the executable name off...

  return LinkAddr;
}


static char getTypeID(const Type *Ty) {
  switch (Ty->getPrimitiveID()) {
  case Type::VoidTyID:    return 'V';
  case Type::BoolTyID:    return 'o';
  case Type::UByteTyID:   return 'B';
  case Type::SByteTyID:   return 'b';
  case Type::UShortTyID:  return 'S';
  case Type::ShortTyID:   return 's';
  case Type::UIntTyID:    return 'I';
  case Type::IntTyID:     return 'i';
  case Type::ULongTyID:   return 'L';
  case Type::LongTyID:    return 'l';
  case Type::FloatTyID:   return 'F';
  case Type::DoubleTyID:  return 'D';
  case Type::PointerTyID: return 'P';
  case Type::FunctionTyID:  return 'M';
  case Type::StructTyID:  return 'T';
  case Type::ArrayTyID:   return 'A';
  case Type::OpaqueTyID:  return 'O';
  default: return 'U';
  }
}

static ExFunc lookupFunction(const Function *M) {
  // Function not found, look it up... start by figuring out what the
  // composite function name should be.
  std::string ExtName = "lle_";
  const FunctionType *MT = M->getFunctionType();
  for (unsigned i = 0; const Type *Ty = MT->getContainedType(i); ++i)
    ExtName += getTypeID(Ty);
  ExtName += "_" + M->getName();

  //cout << "Tried: '" << ExtName << "'\n";
  ExFunc FnPtr = FuncNames[ExtName];
  if (FnPtr == 0)
    FnPtr = (ExFunc)dlsym(RTLD_DEFAULT, ExtName.c_str());
  if (FnPtr == 0)
    FnPtr = FuncNames["lle_X_"+M->getName()];
  if (FnPtr == 0)  // Try calling a generic function... if it exists...
    FnPtr = (ExFunc)dlsym(RTLD_DEFAULT, ("lle_X_"+M->getName()).c_str());
  if (FnPtr != 0)
    Functions.insert(std::make_pair(M, FnPtr));  // Cache for later
  return FnPtr;
}

GenericValue Interpreter::callExternalMethod(Function *M,
                                         const vector<GenericValue> &ArgVals) {
  TheInterpreter = this;

  // Do a lookup to see if the function is in our cache... this should just be a
  // defered annotation!
  std::map<const Function *, ExFunc>::iterator FI = Functions.find(M);
  ExFunc Fn = (FI == Functions.end()) ? lookupFunction(M) : FI->second;
  if (Fn == 0) {
    cout << "Tried to execute an unknown external function: "
	 << M->getType()->getDescription() << " " << M->getName() << "\n";
    return GenericValue();
  }

  // TODO: FIXME when types are not const!
  GenericValue Result = Fn(const_cast<FunctionType*>(M->getFunctionType()),
                           ArgVals);
  return Result;
}


//===----------------------------------------------------------------------===//
//  Functions "exported" to the running application...
//
extern "C" {  // Don't add C++ manglings to llvm mangling :)

// Implement void printstr([ubyte {x N}] *)
GenericValue lle_VP_printstr(FunctionType *M, const vector<GenericValue> &ArgVal){
  assert(ArgVal.size() == 1 && "printstr only takes one argument!");
  cout << (char*)ArgVal[0].PointerVal;
  return GenericValue();
}

// Implement 'void print(X)' for every type...
GenericValue lle_X_print(FunctionType *M, const vector<GenericValue> &ArgVals) {
  assert(ArgVals.size() == 1 && "generic print only takes one argument!");

  Interpreter::print(M->getParamTypes()[0], ArgVals[0]);
  return GenericValue();
}

// Implement 'void printVal(X)' for every type...
GenericValue lle_X_printVal(FunctionType *M, const vector<GenericValue> &ArgVal) {
  assert(ArgVal.size() == 1 && "generic print only takes one argument!");

  // Specialize print([ubyte {x N} ] *) and print(sbyte *)
  if (const PointerType *PTy = 
      dyn_cast<PointerType>(M->getParamTypes()[0].get()))
    if (PTy->getElementType() == Type::SByteTy ||
        isa<ArrayType>(PTy->getElementType())) {
      return lle_VP_printstr(M, ArgVal);
    }

  Interpreter::printValue(M->getParamTypes()[0], ArgVal[0]);
  return GenericValue();
}

// Implement 'void printString(X)'
// Argument must be [ubyte {x N} ] * or sbyte *
GenericValue lle_X_printString(FunctionType *M, const vector<GenericValue> &ArgVal) {
  assert(ArgVal.size() == 1 && "generic print only takes one argument!");
  return lle_VP_printstr(M, ArgVal);
}

// Implement 'void print<TYPE>(X)' for each primitive type or pointer type
#define PRINT_TYPE_FUNC(TYPENAME,TYPEID) \
  GenericValue lle_X_print##TYPENAME(FunctionType *M,\
                                     const vector<GenericValue> &ArgVal) {\
    assert(ArgVal.size() == 1 && "generic print only takes one argument!");\
    assert(M->getParamTypes()[0].get()->getPrimitiveID() == Type::TYPEID);\
    Interpreter::printValue(M->getParamTypes()[0], ArgVal[0]);\
    return GenericValue();\
  }

PRINT_TYPE_FUNC(SByte,   SByteTyID)
PRINT_TYPE_FUNC(UByte,   UByteTyID)
PRINT_TYPE_FUNC(Short,   ShortTyID)
PRINT_TYPE_FUNC(UShort,  UShortTyID)
PRINT_TYPE_FUNC(Int,     IntTyID)
PRINT_TYPE_FUNC(UInt,    UIntTyID)
PRINT_TYPE_FUNC(Long,    LongTyID)
PRINT_TYPE_FUNC(ULong,   ULongTyID)
PRINT_TYPE_FUNC(Float,   FloatTyID)
PRINT_TYPE_FUNC(Double,  DoubleTyID)
PRINT_TYPE_FUNC(Pointer, PointerTyID)


// void putchar(sbyte)
GenericValue lle_Vb_putchar(FunctionType *M, const vector<GenericValue> &Args) {
  cout << Args[0].SByteVal;
  return GenericValue();
}

// int putchar(int)
GenericValue lle_ii_putchar(FunctionType *M, const vector<GenericValue> &Args) {
  cout << ((char)Args[0].IntVal) << std::flush;
  return Args[0];
}

// void putchar(ubyte)
GenericValue lle_VB_putchar(FunctionType *M, const vector<GenericValue> &Args) {
  cout << Args[0].SByteVal << std::flush;
  return Args[0];
}

// void __main()
GenericValue lle_V___main(FunctionType *M, const vector<GenericValue> &Args) {
  return GenericValue();
}

// void exit(int)
GenericValue lle_X_exit(FunctionType *M, const vector<GenericValue> &Args) {
  TheInterpreter->exitCalled(Args[0]);
  return GenericValue();
}

// void abort(void)
GenericValue lle_X_abort(FunctionType *M, const vector<GenericValue> &Args) {
  std::cerr << "***PROGRAM ABORTED***!\n";
  GenericValue GV;
  GV.IntVal = 1;
  TheInterpreter->exitCalled(GV);
  return GenericValue();
}

// void *malloc(uint)
GenericValue lle_X_malloc(FunctionType *M, const vector<GenericValue> &Args) {
  assert(Args.size() == 1 && "Malloc expects one argument!");
  GenericValue GV;
  GV.PointerVal = (PointerTy)malloc(Args[0].UIntVal);
  return GV;
}

// void free(void *)
GenericValue lle_X_free(FunctionType *M, const vector<GenericValue> &Args) {
  assert(Args.size() == 1);
  free((void*)Args[0].PointerVal);
  return GenericValue();
}

// int atoi(char *)
GenericValue lle_X_atoi(FunctionType *M, const vector<GenericValue> &Args) {
  assert(Args.size() == 1);
  GenericValue GV;
  GV.IntVal = atoi((char*)Args[0].PointerVal);
  return GV;
}

// double pow(double, double)
GenericValue lle_X_pow(FunctionType *M, const vector<GenericValue> &Args) {
  assert(Args.size() == 2);
  GenericValue GV;
  GV.DoubleVal = pow(Args[0].DoubleVal, Args[1].DoubleVal);
  return GV;
}

// double exp(double)
GenericValue lle_X_exp(FunctionType *M, const vector<GenericValue> &Args) {
  assert(Args.size() == 1);
  GenericValue GV;
  GV.DoubleVal = exp(Args[0].DoubleVal);
  return GV;
}

// double sqrt(double)
GenericValue lle_X_sqrt(FunctionType *M, const vector<GenericValue> &Args) {
  assert(Args.size() == 1);
  GenericValue GV;
  GV.DoubleVal = sqrt(Args[0].DoubleVal);
  return GV;
}

// double log(double)
GenericValue lle_X_log(FunctionType *M, const vector<GenericValue> &Args) {
  assert(Args.size() == 1);
  GenericValue GV;
  GV.DoubleVal = log(Args[0].DoubleVal);
  return GV;
}

// int isnan(double value);
GenericValue lle_X_isnan(FunctionType *F, const vector<GenericValue> &Args) {
  assert(Args.size() == 1);
  GenericValue GV;
  GV.IntVal = isnan(Args[0].DoubleVal);
  return GV;
}

// double floor(double)
GenericValue lle_X_floor(FunctionType *M, const vector<GenericValue> &Args) {
  assert(Args.size() == 1);
  GenericValue GV;
  GV.DoubleVal = floor(Args[0].DoubleVal);
  return GV;
}

// double drand48()
GenericValue lle_X_drand48(FunctionType *M, const vector<GenericValue> &Args) {
  assert(Args.size() == 0);
  GenericValue GV;
  GV.DoubleVal = drand48();
  return GV;
}

// long lrand48()
GenericValue lle_X_lrand48(FunctionType *M, const vector<GenericValue> &Args) {
  assert(Args.size() == 0);
  GenericValue GV;
  GV.IntVal = lrand48();
  return GV;
}

// void srand48(long)
GenericValue lle_X_srand48(FunctionType *M, const vector<GenericValue> &Args) {
  assert(Args.size() == 1);
  srand48(Args[0].IntVal);
  return GenericValue();
}

// void srand(uint)
GenericValue lle_X_srand(FunctionType *M, const vector<GenericValue> &Args) {
  assert(Args.size() == 1);
  srand(Args[0].UIntVal);
  return GenericValue();
}

// int sprintf(sbyte *, sbyte *, ...) - a very rough implementation to make
// output useful.
GenericValue lle_X_sprintf(FunctionType *M, const vector<GenericValue> &Args) {
  char *OutputBuffer = (char *)Args[0].PointerVal;
  const char *FmtStr = (const char *)Args[1].PointerVal;
  unsigned ArgNo = 2;

  // printf should return # chars printed.  This is completely incorrect, but
  // close enough for now.
  GenericValue GV; GV.IntVal = strlen(FmtStr);
  while (1) {
    switch (*FmtStr) {
    case 0: return GV;             // Null terminator...
    default:                       // Normal nonspecial character
      sprintf(OutputBuffer++, "%c", *FmtStr++);
      break;
    case '\\': {                   // Handle escape codes
      sprintf(OutputBuffer, "%c%c", *FmtStr, *(FmtStr+1));
      FmtStr += 2; OutputBuffer += 2;
      break;
    }
    case '%': {                    // Handle format specifiers
      char FmtBuf[100] = "", Buffer[1000] = "";
      char *FB = FmtBuf;
      *FB++ = *FmtStr++;
      char Last = *FB++ = *FmtStr++;
      unsigned HowLong = 0;
      while (Last != 'c' && Last != 'd' && Last != 'i' && Last != 'u' &&
             Last != 'o' && Last != 'x' && Last != 'X' && Last != 'e' &&
             Last != 'E' && Last != 'g' && Last != 'G' && Last != 'f' &&
             Last != 'p' && Last != 's' && Last != '%') {
        if (Last == 'l' || Last == 'L') HowLong++;  // Keep track of l's
        Last = *FB++ = *FmtStr++;
      }
      *FB = 0;
      
      switch (Last) {
      case '%':
        sprintf(Buffer, FmtBuf); break;
      case 'c':
        sprintf(Buffer, FmtBuf, Args[ArgNo++].IntVal); break;
      case 'd': case 'i':
      case 'u': case 'o':
      case 'x': case 'X':
        if (HowLong >= 1) {
          if (HowLong == 1) {
            // Make sure we use %lld with a 64 bit argument because we might be
            // compiling LLI on a 32 bit compiler.
            unsigned Size = strlen(FmtBuf);
            FmtBuf[Size] = FmtBuf[Size-1];
            FmtBuf[Size+1] = 0;
            FmtBuf[Size-1] = 'l';
          }
          sprintf(Buffer, FmtBuf, Args[ArgNo++].ULongVal);
        } else
          sprintf(Buffer, FmtBuf, Args[ArgNo++].IntVal); break;
      case 'e': case 'E': case 'g': case 'G': case 'f':
        sprintf(Buffer, FmtBuf, Args[ArgNo++].DoubleVal); break;
      case 'p':
        sprintf(Buffer, FmtBuf, (void*)Args[ArgNo++].PointerVal); break;
      case 's': 
        sprintf(Buffer, FmtBuf, (char*)Args[ArgNo++].PointerVal); break;
      default:  cout << "<unknown printf code '" << *FmtStr << "'!>";
        ArgNo++; break;
      }
      strcpy(OutputBuffer, Buffer);
      OutputBuffer += strlen(Buffer);
      }
      break;
    }
  }
}

// int printf(sbyte *, ...) - a very rough implementation to make output useful.
GenericValue lle_X_printf(FunctionType *M, const vector<GenericValue> &Args) {
  char Buffer[10000];
  vector<GenericValue> NewArgs;
  GenericValue GV; GV.PointerVal = (PointerTy)Buffer;
  NewArgs.push_back(GV);
  NewArgs.insert(NewArgs.end(), Args.begin(), Args.end());
  GV = lle_X_sprintf(M, NewArgs);
  cout << Buffer;
  return GV;
}

// int sscanf(const char *format, ...);
GenericValue lle_X_sscanf(FunctionType *M, const vector<GenericValue> &args) {
  assert(args.size() < 10 && "Only handle up to 10 args to sscanf right now!");

  const char *Args[10];
  for (unsigned i = 0; i < args.size(); ++i)
    Args[i] = (const char*)args[i].PointerVal;

  GenericValue GV;
  GV.IntVal = sscanf(Args[0], Args[1], Args[2], Args[3], Args[4],
                     Args[5], Args[6], Args[7], Args[8], Args[9]);
  return GV;
}


// int clock(void) - Profiling implementation
GenericValue lle_i_clock(FunctionType *M, const vector<GenericValue> &Args) {
  extern int clock(void);
  GenericValue GV; GV.IntVal = clock();
  return GV;
}

//===----------------------------------------------------------------------===//
// IO Functions...
//===----------------------------------------------------------------------===//

// getFILE - Turn a pointer in the host address space into a legit pointer in
// the interpreter address space.  For the most part, this is an identity
// transformation, but if the program refers to stdio, stderr, stdin then they
// have pointers that are relative to the __iob array.  If this is the case,
// change the FILE into the REAL stdio stream.
// 
static FILE *getFILE(PointerTy Ptr) {
  static Module *LastMod = 0;
  static PointerTy IOBBase = 0;
  static unsigned FILESize;

  if (LastMod != &TheInterpreter->getModule()) { // Module change or initialize?
    Module *M = LastMod = &TheInterpreter->getModule();

    // Check to see if the currently loaded module contains an __iob symbol...
    GlobalVariable *IOB = 0;
    SymbolTable &ST = M->getSymbolTable();
    for (SymbolTable::iterator I = ST.begin(), E = ST.end(); I != E; ++I) {
      SymbolTable::VarMap &M = I->second;
      for (SymbolTable::VarMap::iterator J = M.begin(), E = M.end();
           J != E; ++J)
        if (J->first == "__iob")
          if ((IOB = dyn_cast<GlobalVariable>(J->second)))
            break;
      if (IOB) break;
    }

#if 0   /// FIXME!  __iob support for LLI
    // If we found an __iob symbol now, find out what the actual address it's
    // held in is...
    if (IOB) {
      // Get the address the array lives in...
      GlobalAddress *Address = 
        (GlobalAddress*)IOB->getOrCreateAnnotation(GlobalAddressAID);
      IOBBase = (PointerTy)(GenericValue*)Address->Ptr;

      // Figure out how big each element of the array is...
      const ArrayType *AT =
        dyn_cast<ArrayType>(IOB->getType()->getElementType());
      if (AT)
        FILESize = TD.getTypeSize(AT->getElementType());
      else
        FILESize = 16*8;  // Default size
    }
#endif
  }

  // Check to see if this is a reference to __iob...
  if (IOBBase) {
    unsigned FDNum = (Ptr-IOBBase)/FILESize;
    if (FDNum == 0)
      return stdin;
    else if (FDNum == 1)
      return stdout;
    else if (FDNum == 2)
      return stderr;
  }

  return (FILE*)Ptr;
}


// FILE *fopen(const char *filename, const char *mode);
GenericValue lle_X_fopen(FunctionType *M, const vector<GenericValue> &Args) {
  assert(Args.size() == 2);
  GenericValue GV;

  GV.PointerVal = (PointerTy)fopen((const char *)Args[0].PointerVal,
                                   (const char *)Args[1].PointerVal);
  return GV;
}

// int fclose(FILE *F);
GenericValue lle_X_fclose(FunctionType *M, const vector<GenericValue> &Args) {
  assert(Args.size() == 1);
  GenericValue GV;

  GV.IntVal = fclose(getFILE(Args[0].PointerVal));
  return GV;
}

// int feof(FILE *stream);
GenericValue lle_X_feof(FunctionType *M, const vector<GenericValue> &Args) {
  assert(Args.size() == 1);
  GenericValue GV;

  GV.IntVal = feof(getFILE(Args[0].PointerVal));
  return GV;
}

// size_t fread(void *ptr, size_t size, size_t nitems, FILE *stream);
GenericValue lle_X_fread(FunctionType *M, const vector<GenericValue> &Args) {
  assert(Args.size() == 4);
  GenericValue GV;

  GV.UIntVal = fread((void*)Args[0].PointerVal, Args[1].UIntVal,
                     Args[2].UIntVal, getFILE(Args[3].PointerVal));
  return GV;
}

// size_t fwrite(const void *ptr, size_t size, size_t nitems, FILE *stream);
GenericValue lle_X_fwrite(FunctionType *M, const vector<GenericValue> &Args) {
  assert(Args.size() == 4);
  GenericValue GV;

  GV.UIntVal = fwrite((void*)Args[0].PointerVal, Args[1].UIntVal,
                      Args[2].UIntVal, getFILE(Args[3].PointerVal));
  return GV;
}

// char *fgets(char *s, int n, FILE *stream);
GenericValue lle_X_fgets(FunctionType *M, const vector<GenericValue> &Args) {
  assert(Args.size() == 3);
  GenericValue GV;

  GV.PointerVal = (PointerTy)fgets((char*)Args[0].PointerVal, Args[1].IntVal,
                                   getFILE(Args[2].PointerVal));
  return GV;
}

// FILE *freopen(const char *path, const char *mode, FILE *stream);
GenericValue lle_X_freopen(FunctionType *M, const vector<GenericValue> &Args) {
  assert(Args.size() == 3);
  GenericValue GV;
  GV.PointerVal = (PointerTy)freopen((char*)Args[0].PointerVal,
                                     (char*)Args[1].PointerVal,
                                     getFILE(Args[2].PointerVal));
  return GV;
}

// int fflush(FILE *stream);
GenericValue lle_X_fflush(FunctionType *M, const vector<GenericValue> &Args) {
  assert(Args.size() == 1);
  GenericValue GV;
  GV.IntVal = fflush(getFILE(Args[0].PointerVal));
  return GV;
}

// int getc(FILE *stream);
GenericValue lle_X_getc(FunctionType *M, const vector<GenericValue> &Args) {
  assert(Args.size() == 1);
  GenericValue GV;
  GV.IntVal = getc(getFILE(Args[0].PointerVal));
  return GV;
}

// int fputc(int C, FILE *stream);
GenericValue lle_X_fputc(FunctionType *M, const vector<GenericValue> &Args) {
  assert(Args.size() == 2);
  GenericValue GV;
  GV.IntVal = fputc(Args[0].IntVal, getFILE(Args[1].PointerVal));
  return GV;
}

// int ungetc(int C, FILE *stream);
GenericValue lle_X_ungetc(FunctionType *M, const vector<GenericValue> &Args) {
  assert(Args.size() == 2);
  GenericValue GV;
  GV.IntVal = ungetc(Args[0].IntVal, getFILE(Args[1].PointerVal));
  return GV;
}

// int fprintf(FILE *,sbyte *, ...) - a very rough implementation to make output
// useful.
GenericValue lle_X_fprintf(FunctionType *M, const vector<GenericValue> &Args) {
  assert(Args.size() > 2);
  char Buffer[10000];
  vector<GenericValue> NewArgs;
  GenericValue GV; GV.PointerVal = (PointerTy)Buffer;
  NewArgs.push_back(GV);
  NewArgs.insert(NewArgs.end(), Args.begin()+1, Args.end());
  GV = lle_X_sprintf(M, NewArgs);

  fputs(Buffer, getFILE(Args[0].PointerVal));
  return GV;
}

} // End extern "C"


void Interpreter::initializeExternalMethods() {
  FuncNames["lle_VP_printstr"] = lle_VP_printstr;
  FuncNames["lle_X_print"] = lle_X_print;
  FuncNames["lle_X_printVal"] = lle_X_printVal;
  FuncNames["lle_X_printString"] = lle_X_printString;
  FuncNames["lle_X_printUByte"] = lle_X_printUByte;
  FuncNames["lle_X_printSByte"] = lle_X_printSByte;
  FuncNames["lle_X_printUShort"] = lle_X_printUShort;
  FuncNames["lle_X_printShort"] = lle_X_printShort;
  FuncNames["lle_X_printInt"] = lle_X_printInt;
  FuncNames["lle_X_printUInt"] = lle_X_printUInt;
  FuncNames["lle_X_printLong"] = lle_X_printLong;
  FuncNames["lle_X_printULong"] = lle_X_printULong;
  FuncNames["lle_X_printFloat"] = lle_X_printFloat;
  FuncNames["lle_X_printDouble"] = lle_X_printDouble;
  FuncNames["lle_X_printPointer"] = lle_X_printPointer;
  FuncNames["lle_Vb_putchar"]     = lle_Vb_putchar;
  FuncNames["lle_ii_putchar"]     = lle_ii_putchar;
  FuncNames["lle_VB_putchar"]     = lle_VB_putchar;
  FuncNames["lle_V___main"]       = lle_V___main;
  FuncNames["lle_X_exit"]         = lle_X_exit;
  FuncNames["lle_X_abort"]        = lle_X_abort;
  FuncNames["lle_X_malloc"]       = lle_X_malloc;
  FuncNames["lle_X_free"]         = lle_X_free;
  FuncNames["lle_X_atoi"]         = lle_X_atoi;
  FuncNames["lle_X_pow"]          = lle_X_pow;
  FuncNames["lle_X_exp"]          = lle_X_exp;
  FuncNames["lle_X_log"]          = lle_X_log;
  FuncNames["lle_X_isnan"]        = lle_X_isnan;
  FuncNames["lle_X_floor"]        = lle_X_floor;
  FuncNames["lle_X_srand"]        = lle_X_srand;
  FuncNames["lle_X_drand48"]      = lle_X_drand48;
  FuncNames["lle_X_srand48"]      = lle_X_srand48;
  FuncNames["lle_X_lrand48"]      = lle_X_lrand48;
  FuncNames["lle_X_sqrt"]         = lle_X_sqrt;
  FuncNames["lle_X_printf"]       = lle_X_printf;
  FuncNames["lle_X_sprintf"]      = lle_X_sprintf;
  FuncNames["lle_X_sscanf"]       = lle_X_sscanf;
  FuncNames["lle_i_clock"]        = lle_i_clock;
  FuncNames["lle_X_fopen"]        = lle_X_fopen;
  FuncNames["lle_X_fclose"]       = lle_X_fclose;
  FuncNames["lle_X_feof"]         = lle_X_feof;
  FuncNames["lle_X_fread"]        = lle_X_fread;
  FuncNames["lle_X_fwrite"]       = lle_X_fwrite;
  FuncNames["lle_X_fgets"]        = lle_X_fgets;
  FuncNames["lle_X_fflush"]       = lle_X_fflush;
  FuncNames["lle_X_fgetc"]        = lle_X_getc;
  FuncNames["lle_X_getc"]         = lle_X_getc;
  FuncNames["lle_X_fputc"]        = lle_X_fputc;
  FuncNames["lle_X_ungetc"]       = lle_X_ungetc;
  FuncNames["lle_X_fprintf"]      = lle_X_fprintf;
  FuncNames["lle_X_freopen"]      = lle_X_freopen;
}