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