1//===- BuildLibCalls.cpp - Utility builder for libcalls -------------------===//
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 implements some functions that will create standard C libcalls.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/Transforms/Utils/BuildLibCalls.h"
15#include "llvm/ADT/SmallString.h"
16#include "llvm/IR/Constants.h"
17#include "llvm/IR/DataLayout.h"
18#include "llvm/IR/Function.h"
19#include "llvm/IR/IRBuilder.h"
20#include "llvm/IR/Intrinsics.h"
21#include "llvm/IR/LLVMContext.h"
22#include "llvm/IR/Module.h"
23#include "llvm/IR/Type.h"
24#include "llvm/Target/TargetLibraryInfo.h"
25
26using namespace llvm;
27
28/// CastToCStr - Return V if it is an i8*, otherwise cast it to i8*.
29Value *llvm::CastToCStr(Value *V, IRBuilder<> &B) {
30  unsigned AS = V->getType()->getPointerAddressSpace();
31  return B.CreateBitCast(V, B.getInt8PtrTy(AS), "cstr");
32}
33
34/// EmitStrLen - Emit a call to the strlen function to the builder, for the
35/// specified pointer.  This always returns an integer value of size intptr_t.
36Value *llvm::EmitStrLen(Value *Ptr, IRBuilder<> &B, const DataLayout *TD,
37                        const TargetLibraryInfo *TLI) {
38  if (!TLI->has(LibFunc::strlen))
39    return nullptr;
40
41  Module *M = B.GetInsertBlock()->getParent()->getParent();
42  AttributeSet AS[2];
43  AS[0] = AttributeSet::get(M->getContext(), 1, Attribute::NoCapture);
44  Attribute::AttrKind AVs[2] = { Attribute::ReadOnly, Attribute::NoUnwind };
45  AS[1] = AttributeSet::get(M->getContext(), AttributeSet::FunctionIndex,
46                            ArrayRef<Attribute::AttrKind>(AVs, 2));
47
48  LLVMContext &Context = B.GetInsertBlock()->getContext();
49  Constant *StrLen = M->getOrInsertFunction("strlen",
50                                            AttributeSet::get(M->getContext(),
51                                                              AS),
52                                            TD->getIntPtrType(Context),
53                                            B.getInt8PtrTy(),
54                                            NULL);
55  CallInst *CI = B.CreateCall(StrLen, CastToCStr(Ptr, B), "strlen");
56  if (const Function *F = dyn_cast<Function>(StrLen->stripPointerCasts()))
57    CI->setCallingConv(F->getCallingConv());
58
59  return CI;
60}
61
62/// EmitStrNLen - Emit a call to the strnlen function to the builder, for the
63/// specified pointer.  Ptr is required to be some pointer type, MaxLen must
64/// be of size_t type, and the return value has 'intptr_t' type.
65Value *llvm::EmitStrNLen(Value *Ptr, Value *MaxLen, IRBuilder<> &B,
66                         const DataLayout *TD, const TargetLibraryInfo *TLI) {
67  if (!TLI->has(LibFunc::strnlen))
68    return nullptr;
69
70  Module *M = B.GetInsertBlock()->getParent()->getParent();
71  AttributeSet AS[2];
72  AS[0] = AttributeSet::get(M->getContext(), 1, Attribute::NoCapture);
73  Attribute::AttrKind AVs[2] = { Attribute::ReadOnly, Attribute::NoUnwind };
74  AS[1] = AttributeSet::get(M->getContext(), AttributeSet::FunctionIndex,
75                            ArrayRef<Attribute::AttrKind>(AVs, 2));
76
77  LLVMContext &Context = B.GetInsertBlock()->getContext();
78  Constant *StrNLen = M->getOrInsertFunction("strnlen",
79                                             AttributeSet::get(M->getContext(),
80                                                              AS),
81                                             TD->getIntPtrType(Context),
82                                             B.getInt8PtrTy(),
83                                             TD->getIntPtrType(Context),
84                                             NULL);
85  CallInst *CI = B.CreateCall2(StrNLen, CastToCStr(Ptr, B), MaxLen, "strnlen");
86  if (const Function *F = dyn_cast<Function>(StrNLen->stripPointerCasts()))
87    CI->setCallingConv(F->getCallingConv());
88
89  return CI;
90}
91
92/// EmitStrChr - Emit a call to the strchr function to the builder, for the
93/// specified pointer and character.  Ptr is required to be some pointer type,
94/// and the return value has 'i8*' type.
95Value *llvm::EmitStrChr(Value *Ptr, char C, IRBuilder<> &B,
96                        const DataLayout *TD, const TargetLibraryInfo *TLI) {
97  if (!TLI->has(LibFunc::strchr))
98    return nullptr;
99
100  Module *M = B.GetInsertBlock()->getParent()->getParent();
101  Attribute::AttrKind AVs[2] = { Attribute::ReadOnly, Attribute::NoUnwind };
102  AttributeSet AS =
103    AttributeSet::get(M->getContext(), AttributeSet::FunctionIndex,
104                      ArrayRef<Attribute::AttrKind>(AVs, 2));
105
106  Type *I8Ptr = B.getInt8PtrTy();
107  Type *I32Ty = B.getInt32Ty();
108  Constant *StrChr = M->getOrInsertFunction("strchr",
109                                            AttributeSet::get(M->getContext(),
110                                                             AS),
111                                            I8Ptr, I8Ptr, I32Ty, NULL);
112  CallInst *CI = B.CreateCall2(StrChr, CastToCStr(Ptr, B),
113                               ConstantInt::get(I32Ty, C), "strchr");
114  if (const Function *F = dyn_cast<Function>(StrChr->stripPointerCasts()))
115    CI->setCallingConv(F->getCallingConv());
116  return CI;
117}
118
119/// EmitStrNCmp - Emit a call to the strncmp function to the builder.
120Value *llvm::EmitStrNCmp(Value *Ptr1, Value *Ptr2, Value *Len,
121                         IRBuilder<> &B, const DataLayout *TD,
122                         const TargetLibraryInfo *TLI) {
123  if (!TLI->has(LibFunc::strncmp))
124    return nullptr;
125
126  Module *M = B.GetInsertBlock()->getParent()->getParent();
127  AttributeSet AS[3];
128  AS[0] = AttributeSet::get(M->getContext(), 1, Attribute::NoCapture);
129  AS[1] = AttributeSet::get(M->getContext(), 2, Attribute::NoCapture);
130  Attribute::AttrKind AVs[2] = { Attribute::ReadOnly, Attribute::NoUnwind };
131  AS[2] = AttributeSet::get(M->getContext(), AttributeSet::FunctionIndex,
132                            ArrayRef<Attribute::AttrKind>(AVs, 2));
133
134  LLVMContext &Context = B.GetInsertBlock()->getContext();
135  Value *StrNCmp = M->getOrInsertFunction("strncmp",
136                                          AttributeSet::get(M->getContext(),
137                                                           AS),
138                                          B.getInt32Ty(),
139                                          B.getInt8PtrTy(),
140                                          B.getInt8PtrTy(),
141                                          TD->getIntPtrType(Context), NULL);
142  CallInst *CI = B.CreateCall3(StrNCmp, CastToCStr(Ptr1, B),
143                               CastToCStr(Ptr2, B), Len, "strncmp");
144
145  if (const Function *F = dyn_cast<Function>(StrNCmp->stripPointerCasts()))
146    CI->setCallingConv(F->getCallingConv());
147
148  return CI;
149}
150
151/// EmitStrCpy - Emit a call to the strcpy function to the builder, for the
152/// specified pointer arguments.
153Value *llvm::EmitStrCpy(Value *Dst, Value *Src, IRBuilder<> &B,
154                        const DataLayout *TD, const TargetLibraryInfo *TLI,
155                        StringRef Name) {
156  if (!TLI->has(LibFunc::strcpy))
157    return nullptr;
158
159  Module *M = B.GetInsertBlock()->getParent()->getParent();
160  AttributeSet AS[2];
161  AS[0] = AttributeSet::get(M->getContext(), 2, Attribute::NoCapture);
162  AS[1] = AttributeSet::get(M->getContext(), AttributeSet::FunctionIndex,
163                            Attribute::NoUnwind);
164  Type *I8Ptr = B.getInt8PtrTy();
165  Value *StrCpy = M->getOrInsertFunction(Name,
166                                         AttributeSet::get(M->getContext(), AS),
167                                         I8Ptr, I8Ptr, I8Ptr, NULL);
168  CallInst *CI = B.CreateCall2(StrCpy, CastToCStr(Dst, B), CastToCStr(Src, B),
169                               Name);
170  if (const Function *F = dyn_cast<Function>(StrCpy->stripPointerCasts()))
171    CI->setCallingConv(F->getCallingConv());
172  return CI;
173}
174
175/// EmitStrNCpy - Emit a call to the strncpy function to the builder, for the
176/// specified pointer arguments.
177Value *llvm::EmitStrNCpy(Value *Dst, Value *Src, Value *Len,
178                         IRBuilder<> &B, const DataLayout *TD,
179                         const TargetLibraryInfo *TLI, StringRef Name) {
180  if (!TLI->has(LibFunc::strncpy))
181    return nullptr;
182
183  Module *M = B.GetInsertBlock()->getParent()->getParent();
184  AttributeSet AS[2];
185  AS[0] = AttributeSet::get(M->getContext(), 2, Attribute::NoCapture);
186  AS[1] = AttributeSet::get(M->getContext(), AttributeSet::FunctionIndex,
187                            Attribute::NoUnwind);
188  Type *I8Ptr = B.getInt8PtrTy();
189  Value *StrNCpy = M->getOrInsertFunction(Name,
190                                          AttributeSet::get(M->getContext(),
191                                                            AS),
192                                          I8Ptr, I8Ptr, I8Ptr,
193                                          Len->getType(), NULL);
194  CallInst *CI = B.CreateCall3(StrNCpy, CastToCStr(Dst, B), CastToCStr(Src, B),
195                               Len, "strncpy");
196  if (const Function *F = dyn_cast<Function>(StrNCpy->stripPointerCasts()))
197    CI->setCallingConv(F->getCallingConv());
198  return CI;
199}
200
201/// EmitMemCpyChk - Emit a call to the __memcpy_chk function to the builder.
202/// This expects that the Len and ObjSize have type 'intptr_t' and Dst/Src
203/// are pointers.
204Value *llvm::EmitMemCpyChk(Value *Dst, Value *Src, Value *Len, Value *ObjSize,
205                           IRBuilder<> &B, const DataLayout *TD,
206                           const TargetLibraryInfo *TLI) {
207  if (!TLI->has(LibFunc::memcpy_chk))
208    return nullptr;
209
210  Module *M = B.GetInsertBlock()->getParent()->getParent();
211  AttributeSet AS;
212  AS = AttributeSet::get(M->getContext(), AttributeSet::FunctionIndex,
213                         Attribute::NoUnwind);
214  LLVMContext &Context = B.GetInsertBlock()->getContext();
215  Value *MemCpy = M->getOrInsertFunction("__memcpy_chk",
216                                         AttributeSet::get(M->getContext(), AS),
217                                         B.getInt8PtrTy(),
218                                         B.getInt8PtrTy(),
219                                         B.getInt8PtrTy(),
220                                         TD->getIntPtrType(Context),
221                                         TD->getIntPtrType(Context), NULL);
222  Dst = CastToCStr(Dst, B);
223  Src = CastToCStr(Src, B);
224  CallInst *CI = B.CreateCall4(MemCpy, Dst, Src, Len, ObjSize);
225  if (const Function *F = dyn_cast<Function>(MemCpy->stripPointerCasts()))
226    CI->setCallingConv(F->getCallingConv());
227  return CI;
228}
229
230/// EmitMemChr - Emit a call to the memchr function.  This assumes that Ptr is
231/// a pointer, Val is an i32 value, and Len is an 'intptr_t' value.
232Value *llvm::EmitMemChr(Value *Ptr, Value *Val,
233                        Value *Len, IRBuilder<> &B, const DataLayout *TD,
234                        const TargetLibraryInfo *TLI) {
235  if (!TLI->has(LibFunc::memchr))
236    return nullptr;
237
238  Module *M = B.GetInsertBlock()->getParent()->getParent();
239  AttributeSet AS;
240  Attribute::AttrKind AVs[2] = { Attribute::ReadOnly, Attribute::NoUnwind };
241  AS = AttributeSet::get(M->getContext(), AttributeSet::FunctionIndex,
242                         ArrayRef<Attribute::AttrKind>(AVs, 2));
243  LLVMContext &Context = B.GetInsertBlock()->getContext();
244  Value *MemChr = M->getOrInsertFunction("memchr",
245                                         AttributeSet::get(M->getContext(), AS),
246                                         B.getInt8PtrTy(),
247                                         B.getInt8PtrTy(),
248                                         B.getInt32Ty(),
249                                         TD->getIntPtrType(Context),
250                                         NULL);
251  CallInst *CI = B.CreateCall3(MemChr, CastToCStr(Ptr, B), Val, Len, "memchr");
252
253  if (const Function *F = dyn_cast<Function>(MemChr->stripPointerCasts()))
254    CI->setCallingConv(F->getCallingConv());
255
256  return CI;
257}
258
259/// EmitMemCmp - Emit a call to the memcmp function.
260Value *llvm::EmitMemCmp(Value *Ptr1, Value *Ptr2,
261                        Value *Len, IRBuilder<> &B, const DataLayout *TD,
262                        const TargetLibraryInfo *TLI) {
263  if (!TLI->has(LibFunc::memcmp))
264    return nullptr;
265
266  Module *M = B.GetInsertBlock()->getParent()->getParent();
267  AttributeSet AS[3];
268  AS[0] = AttributeSet::get(M->getContext(), 1, Attribute::NoCapture);
269  AS[1] = AttributeSet::get(M->getContext(), 2, Attribute::NoCapture);
270  Attribute::AttrKind AVs[2] = { Attribute::ReadOnly, Attribute::NoUnwind };
271  AS[2] = AttributeSet::get(M->getContext(), AttributeSet::FunctionIndex,
272                            ArrayRef<Attribute::AttrKind>(AVs, 2));
273
274  LLVMContext &Context = B.GetInsertBlock()->getContext();
275  Value *MemCmp = M->getOrInsertFunction("memcmp",
276                                         AttributeSet::get(M->getContext(), AS),
277                                         B.getInt32Ty(),
278                                         B.getInt8PtrTy(),
279                                         B.getInt8PtrTy(),
280                                         TD->getIntPtrType(Context), NULL);
281  CallInst *CI = B.CreateCall3(MemCmp, CastToCStr(Ptr1, B), CastToCStr(Ptr2, B),
282                               Len, "memcmp");
283
284  if (const Function *F = dyn_cast<Function>(MemCmp->stripPointerCasts()))
285    CI->setCallingConv(F->getCallingConv());
286
287  return CI;
288}
289
290/// Append a suffix to the function name according to the type of 'Op'.
291static void AppendTypeSuffix(Value *Op, StringRef &Name, SmallString<20> &NameBuffer) {
292  if (!Op->getType()->isDoubleTy()) {
293      NameBuffer += Name;
294
295    if (Op->getType()->isFloatTy())
296      NameBuffer += 'f';
297    else
298      NameBuffer += 'l';
299
300    Name = NameBuffer;
301  }
302  return;
303}
304
305/// EmitUnaryFloatFnCall - Emit a call to the unary function named 'Name' (e.g.
306/// 'floor').  This function is known to take a single of type matching 'Op' and
307/// returns one value with the same type.  If 'Op' is a long double, 'l' is
308/// added as the suffix of name, if 'Op' is a float, we add a 'f' suffix.
309Value *llvm::EmitUnaryFloatFnCall(Value *Op, StringRef Name, IRBuilder<> &B,
310                                  const AttributeSet &Attrs) {
311  SmallString<20> NameBuffer;
312  AppendTypeSuffix(Op, Name, NameBuffer);
313
314  Module *M = B.GetInsertBlock()->getParent()->getParent();
315  Value *Callee = M->getOrInsertFunction(Name, Op->getType(),
316                                         Op->getType(), NULL);
317  CallInst *CI = B.CreateCall(Callee, Op, Name);
318  CI->setAttributes(Attrs);
319  if (const Function *F = dyn_cast<Function>(Callee->stripPointerCasts()))
320    CI->setCallingConv(F->getCallingConv());
321
322  return CI;
323}
324
325/// EmitBinaryFloatFnCall - Emit a call to the binary function named 'Name'
326/// (e.g. 'fmin').  This function is known to take type matching 'Op1' and 'Op2'
327/// and return one value with the same type.  If 'Op1/Op2' are long double, 'l'
328/// is added as the suffix of name, if 'Op1/Op2' is a float, we add a 'f'
329/// suffix.
330Value *llvm::EmitBinaryFloatFnCall(Value *Op1, Value *Op2, StringRef Name,
331                                  IRBuilder<> &B, const AttributeSet &Attrs) {
332  SmallString<20> NameBuffer;
333  AppendTypeSuffix(Op1, Name, NameBuffer);
334
335  Module *M = B.GetInsertBlock()->getParent()->getParent();
336  Value *Callee = M->getOrInsertFunction(Name, Op1->getType(),
337                                         Op1->getType(), Op2->getType(), NULL);
338  CallInst *CI = B.CreateCall2(Callee, Op1, Op2, Name);
339  CI->setAttributes(Attrs);
340  if (const Function *F = dyn_cast<Function>(Callee->stripPointerCasts()))
341    CI->setCallingConv(F->getCallingConv());
342
343  return CI;
344}
345
346/// EmitPutChar - Emit a call to the putchar function.  This assumes that Char
347/// is an integer.
348Value *llvm::EmitPutChar(Value *Char, IRBuilder<> &B, const DataLayout *TD,
349                         const TargetLibraryInfo *TLI) {
350  if (!TLI->has(LibFunc::putchar))
351    return nullptr;
352
353  Module *M = B.GetInsertBlock()->getParent()->getParent();
354  Value *PutChar = M->getOrInsertFunction("putchar", B.getInt32Ty(),
355                                          B.getInt32Ty(), NULL);
356  CallInst *CI = B.CreateCall(PutChar,
357                              B.CreateIntCast(Char,
358                              B.getInt32Ty(),
359                              /*isSigned*/true,
360                              "chari"),
361                              "putchar");
362
363  if (const Function *F = dyn_cast<Function>(PutChar->stripPointerCasts()))
364    CI->setCallingConv(F->getCallingConv());
365  return CI;
366}
367
368/// EmitPutS - Emit a call to the puts function.  This assumes that Str is
369/// some pointer.
370Value *llvm::EmitPutS(Value *Str, IRBuilder<> &B, const DataLayout *TD,
371                      const TargetLibraryInfo *TLI) {
372  if (!TLI->has(LibFunc::puts))
373    return nullptr;
374
375  Module *M = B.GetInsertBlock()->getParent()->getParent();
376  AttributeSet AS[2];
377  AS[0] = AttributeSet::get(M->getContext(), 1, Attribute::NoCapture);
378  AS[1] = AttributeSet::get(M->getContext(), AttributeSet::FunctionIndex,
379                            Attribute::NoUnwind);
380
381  Value *PutS = M->getOrInsertFunction("puts",
382                                       AttributeSet::get(M->getContext(), AS),
383                                       B.getInt32Ty(),
384                                       B.getInt8PtrTy(),
385                                       NULL);
386  CallInst *CI = B.CreateCall(PutS, CastToCStr(Str, B), "puts");
387  if (const Function *F = dyn_cast<Function>(PutS->stripPointerCasts()))
388    CI->setCallingConv(F->getCallingConv());
389  return CI;
390}
391
392/// EmitFPutC - Emit a call to the fputc function.  This assumes that Char is
393/// an integer and File is a pointer to FILE.
394Value *llvm::EmitFPutC(Value *Char, Value *File, IRBuilder<> &B,
395                       const DataLayout *TD, const TargetLibraryInfo *TLI) {
396  if (!TLI->has(LibFunc::fputc))
397    return nullptr;
398
399  Module *M = B.GetInsertBlock()->getParent()->getParent();
400  AttributeSet AS[2];
401  AS[0] = AttributeSet::get(M->getContext(), 2, Attribute::NoCapture);
402  AS[1] = AttributeSet::get(M->getContext(), AttributeSet::FunctionIndex,
403                            Attribute::NoUnwind);
404  Constant *F;
405  if (File->getType()->isPointerTy())
406    F = M->getOrInsertFunction("fputc",
407                               AttributeSet::get(M->getContext(), AS),
408                               B.getInt32Ty(),
409                               B.getInt32Ty(), File->getType(),
410                               NULL);
411  else
412    F = M->getOrInsertFunction("fputc",
413                               B.getInt32Ty(),
414                               B.getInt32Ty(),
415                               File->getType(), NULL);
416  Char = B.CreateIntCast(Char, B.getInt32Ty(), /*isSigned*/true,
417                         "chari");
418  CallInst *CI = B.CreateCall2(F, Char, File, "fputc");
419
420  if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
421    CI->setCallingConv(Fn->getCallingConv());
422  return CI;
423}
424
425/// EmitFPutS - Emit a call to the puts function.  Str is required to be a
426/// pointer and File is a pointer to FILE.
427Value *llvm::EmitFPutS(Value *Str, Value *File, IRBuilder<> &B,
428                       const DataLayout *TD, const TargetLibraryInfo *TLI) {
429  if (!TLI->has(LibFunc::fputs))
430    return nullptr;
431
432  Module *M = B.GetInsertBlock()->getParent()->getParent();
433  AttributeSet AS[3];
434  AS[0] = AttributeSet::get(M->getContext(), 1, Attribute::NoCapture);
435  AS[1] = AttributeSet::get(M->getContext(), 2, Attribute::NoCapture);
436  AS[2] = AttributeSet::get(M->getContext(), AttributeSet::FunctionIndex,
437                            Attribute::NoUnwind);
438  StringRef FPutsName = TLI->getName(LibFunc::fputs);
439  Constant *F;
440  if (File->getType()->isPointerTy())
441    F = M->getOrInsertFunction(FPutsName,
442                               AttributeSet::get(M->getContext(), AS),
443                               B.getInt32Ty(),
444                               B.getInt8PtrTy(),
445                               File->getType(), NULL);
446  else
447    F = M->getOrInsertFunction(FPutsName, B.getInt32Ty(),
448                               B.getInt8PtrTy(),
449                               File->getType(), NULL);
450  CallInst *CI = B.CreateCall2(F, CastToCStr(Str, B), File, "fputs");
451
452  if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
453    CI->setCallingConv(Fn->getCallingConv());
454  return CI;
455}
456
457/// EmitFWrite - Emit a call to the fwrite function.  This assumes that Ptr is
458/// a pointer, Size is an 'intptr_t', and File is a pointer to FILE.
459Value *llvm::EmitFWrite(Value *Ptr, Value *Size, Value *File,
460                        IRBuilder<> &B, const DataLayout *TD,
461                        const TargetLibraryInfo *TLI) {
462  if (!TLI->has(LibFunc::fwrite))
463    return nullptr;
464
465  Module *M = B.GetInsertBlock()->getParent()->getParent();
466  AttributeSet AS[3];
467  AS[0] = AttributeSet::get(M->getContext(), 1, Attribute::NoCapture);
468  AS[1] = AttributeSet::get(M->getContext(), 4, Attribute::NoCapture);
469  AS[2] = AttributeSet::get(M->getContext(), AttributeSet::FunctionIndex,
470                            Attribute::NoUnwind);
471  LLVMContext &Context = B.GetInsertBlock()->getContext();
472  StringRef FWriteName = TLI->getName(LibFunc::fwrite);
473  Constant *F;
474  if (File->getType()->isPointerTy())
475    F = M->getOrInsertFunction(FWriteName,
476                               AttributeSet::get(M->getContext(), AS),
477                               TD->getIntPtrType(Context),
478                               B.getInt8PtrTy(),
479                               TD->getIntPtrType(Context),
480                               TD->getIntPtrType(Context),
481                               File->getType(), NULL);
482  else
483    F = M->getOrInsertFunction(FWriteName, TD->getIntPtrType(Context),
484                               B.getInt8PtrTy(),
485                               TD->getIntPtrType(Context),
486                               TD->getIntPtrType(Context),
487                               File->getType(), NULL);
488  CallInst *CI = B.CreateCall4(F, CastToCStr(Ptr, B), Size,
489                        ConstantInt::get(TD->getIntPtrType(Context), 1), File);
490
491  if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
492    CI->setCallingConv(Fn->getCallingConv());
493  return CI;
494}
495
496SimplifyFortifiedLibCalls::~SimplifyFortifiedLibCalls() { }
497
498bool SimplifyFortifiedLibCalls::fold(CallInst *CI, const DataLayout *TD,
499                                     const TargetLibraryInfo *TLI) {
500  // We really need DataLayout for later.
501  if (!TD) return false;
502
503  this->CI = CI;
504  Function *Callee = CI->getCalledFunction();
505  StringRef Name = Callee->getName();
506  FunctionType *FT = Callee->getFunctionType();
507  LLVMContext &Context = CI->getParent()->getContext();
508  IRBuilder<> B(CI);
509
510  if (Name == "__memcpy_chk") {
511    // Check if this has the right signature.
512    if (FT->getNumParams() != 4 || FT->getReturnType() != FT->getParamType(0) ||
513        !FT->getParamType(0)->isPointerTy() ||
514        !FT->getParamType(1)->isPointerTy() ||
515        FT->getParamType(2) != TD->getIntPtrType(Context) ||
516        FT->getParamType(3) != TD->getIntPtrType(Context))
517      return false;
518
519    if (isFoldable(3, 2, false)) {
520      B.CreateMemCpy(CI->getArgOperand(0), CI->getArgOperand(1),
521                     CI->getArgOperand(2), 1);
522      replaceCall(CI->getArgOperand(0));
523      return true;
524    }
525    return false;
526  }
527
528  // Should be similar to memcpy.
529  if (Name == "__mempcpy_chk") {
530    return false;
531  }
532
533  if (Name == "__memmove_chk") {
534    // Check if this has the right signature.
535    if (FT->getNumParams() != 4 || FT->getReturnType() != FT->getParamType(0) ||
536        !FT->getParamType(0)->isPointerTy() ||
537        !FT->getParamType(1)->isPointerTy() ||
538        FT->getParamType(2) != TD->getIntPtrType(Context) ||
539        FT->getParamType(3) != TD->getIntPtrType(Context))
540      return false;
541
542    if (isFoldable(3, 2, false)) {
543      B.CreateMemMove(CI->getArgOperand(0), CI->getArgOperand(1),
544                      CI->getArgOperand(2), 1);
545      replaceCall(CI->getArgOperand(0));
546      return true;
547    }
548    return false;
549  }
550
551  if (Name == "__memset_chk") {
552    // Check if this has the right signature.
553    if (FT->getNumParams() != 4 || FT->getReturnType() != FT->getParamType(0) ||
554        !FT->getParamType(0)->isPointerTy() ||
555        !FT->getParamType(1)->isIntegerTy() ||
556        FT->getParamType(2) != TD->getIntPtrType(Context) ||
557        FT->getParamType(3) != TD->getIntPtrType(Context))
558      return false;
559
560    if (isFoldable(3, 2, false)) {
561      Value *Val = B.CreateIntCast(CI->getArgOperand(1), B.getInt8Ty(),
562                                   false);
563      B.CreateMemSet(CI->getArgOperand(0), Val, CI->getArgOperand(2), 1);
564      replaceCall(CI->getArgOperand(0));
565      return true;
566    }
567    return false;
568  }
569
570  if (Name == "__strcpy_chk" || Name == "__stpcpy_chk") {
571    // Check if this has the right signature.
572    if (FT->getNumParams() != 3 ||
573        FT->getReturnType() != FT->getParamType(0) ||
574        FT->getParamType(0) != FT->getParamType(1) ||
575        FT->getParamType(0) != Type::getInt8PtrTy(Context) ||
576        FT->getParamType(2) != TD->getIntPtrType(Context))
577      return 0;
578
579
580    // If a) we don't have any length information, or b) we know this will
581    // fit then just lower to a plain st[rp]cpy. Otherwise we'll keep our
582    // st[rp]cpy_chk call which may fail at runtime if the size is too long.
583    // TODO: It might be nice to get a maximum length out of the possible
584    // string lengths for varying.
585    if (isFoldable(2, 1, true)) {
586      Value *Ret = EmitStrCpy(CI->getArgOperand(0), CI->getArgOperand(1), B, TD,
587                              TLI, Name.substr(2, 6));
588      if (!Ret)
589        return false;
590      replaceCall(Ret);
591      return true;
592    }
593    return false;
594  }
595
596  if (Name == "__strncpy_chk" || Name == "__stpncpy_chk") {
597    // Check if this has the right signature.
598    if (FT->getNumParams() != 4 || FT->getReturnType() != FT->getParamType(0) ||
599        FT->getParamType(0) != FT->getParamType(1) ||
600        FT->getParamType(0) != Type::getInt8PtrTy(Context) ||
601        !FT->getParamType(2)->isIntegerTy() ||
602        FT->getParamType(3) != TD->getIntPtrType(Context))
603      return false;
604
605    if (isFoldable(3, 2, false)) {
606      Value *Ret = EmitStrNCpy(CI->getArgOperand(0), CI->getArgOperand(1),
607                               CI->getArgOperand(2), B, TD, TLI,
608                               Name.substr(2, 7));
609      if (!Ret)
610        return false;
611      replaceCall(Ret);
612      return true;
613    }
614    return false;
615  }
616
617  if (Name == "__strcat_chk") {
618    return false;
619  }
620
621  if (Name == "__strncat_chk") {
622    return false;
623  }
624
625  return false;
626}
627