lib/Transforms/Utils/BuildLibCalls.cpp - llvm - Git at Google

 //===- BuildLibCalls.cpp - Utility builder for libcalls -------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements some functions that will create standard C libcalls.
 //
 //===----------------------------------------------------------------------===//

 #include "llvm/Transforms/Utils/BuildLibCalls.h"
 #include "llvm/Type.h"
 #include "llvm/Constants.h"
 #include "llvm/Function.h"
 #include "llvm/Module.h"
 #include "llvm/Support/IRBuilder.h"
 #include "llvm/Target/TargetData.h"
 #include "llvm/LLVMContext.h"
 #include "llvm/Intrinsics.h"

 using namespace llvm;

 /// CastToCStr - Return V if it is an i8*, otherwise cast it to i8*.
 Value *llvm::CastToCStr(Value *V, IRBuilder<> &B) {
   return B.CreateBitCast(V, B.getInt8PtrTy(), "cstr");
 }

 /// EmitStrLen - Emit a call to the strlen function to the builder, for the
 /// specified pointer.  This always returns an integer value of size intptr_t.
 Value *llvm::EmitStrLen(Value *Ptr, IRBuilder<> &B, const TargetData *TD) {
   Module *M = B.GetInsertBlock()->getParent()->getParent();
   AttributeWithIndex AWI[2];
   AWI[0] = AttributeWithIndex::get(1, Attribute::NoCapture);
   AWI[1] = AttributeWithIndex::get(~0u, Attribute::ReadOnly |
                                    Attribute::NoUnwind);

   LLVMContext &Context = B.GetInsertBlock()->getContext();
   Constant *StrLen = M->getOrInsertFunction("strlen", AttrListPtr::get(AWI, 2),
                                             TD->getIntPtrType(Context),
                                             B.getInt8PtrTy(),
                                             NULL);
   CallInst *CI = B.CreateCall(StrLen, CastToCStr(Ptr, B), "strlen");
   if (const Function *F = dyn_cast<Function>(StrLen->stripPointerCasts()))
     CI->setCallingConv(F->getCallingConv());

   return CI;
 }

 /// EmitStrChr - Emit a call to the strchr function to the builder, for the
 /// specified pointer and character.  Ptr is required to be some pointer type,
 /// and the return value has 'i8*' type.
 Value *llvm::EmitStrChr(Value *Ptr, char C, IRBuilder<> &B,
                         const TargetData *TD) {
   Module *M = B.GetInsertBlock()->getParent()->getParent();
   AttributeWithIndex AWI =
     AttributeWithIndex::get(~0u, Attribute::ReadOnly | Attribute::NoUnwind);

   Type *I8Ptr = B.getInt8PtrTy();
   Type *I32Ty = B.getInt32Ty();
   Constant *StrChr = M->getOrInsertFunction("strchr", AttrListPtr::get(&AWI, 1),
                                             I8Ptr, I8Ptr, I32Ty, NULL);
   CallInst *CI = B.CreateCall2(StrChr, CastToCStr(Ptr, B),
                                ConstantInt::get(I32Ty, C), "strchr");
   if (const Function *F = dyn_cast<Function>(StrChr->stripPointerCasts()))
     CI->setCallingConv(F->getCallingConv());
   return CI;
 }

 /// EmitStrNCmp - Emit a call to the strncmp function to the builder.
 Value *llvm::EmitStrNCmp(Value *Ptr1, Value *Ptr2, Value *Len,
                          IRBuilder<> &B, const TargetData *TD) {
   Module *M = B.GetInsertBlock()->getParent()->getParent();
   AttributeWithIndex AWI[3];
   AWI[0] = AttributeWithIndex::get(1, Attribute::NoCapture);
   AWI[1] = AttributeWithIndex::get(2, Attribute::NoCapture);
   AWI[2] = AttributeWithIndex::get(~0u, Attribute::ReadOnly |
                                    Attribute::NoUnwind);

   LLVMContext &Context = B.GetInsertBlock()->getContext();
   Value *StrNCmp = M->getOrInsertFunction("strncmp", AttrListPtr::get(AWI, 3),
                                           B.getInt32Ty(),
                                           B.getInt8PtrTy(),
                                           B.getInt8PtrTy(),
                                           TD->getIntPtrType(Context), NULL);
   CallInst *CI = B.CreateCall3(StrNCmp, CastToCStr(Ptr1, B),
                                CastToCStr(Ptr2, B), Len, "strncmp");

   if (const Function *F = dyn_cast<Function>(StrNCmp->stripPointerCasts()))
     CI->setCallingConv(F->getCallingConv());

   return CI;
 }

 /// EmitStrCpy - Emit a call to the strcpy function to the builder, for the
 /// specified pointer arguments.
 Value *llvm::EmitStrCpy(Value *Dst, Value *Src, IRBuilder<> &B,
                         const TargetData *TD, StringRef Name) {
   Module *M = B.GetInsertBlock()->getParent()->getParent();
   AttributeWithIndex AWI[2];
   AWI[0] = AttributeWithIndex::get(2, Attribute::NoCapture);
   AWI[1] = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
   Type *I8Ptr = B.getInt8PtrTy();
   Value *StrCpy = M->getOrInsertFunction(Name, AttrListPtr::get(AWI, 2),
                                          I8Ptr, I8Ptr, I8Ptr, NULL);
   CallInst *CI = B.CreateCall2(StrCpy, CastToCStr(Dst, B), CastToCStr(Src, B),
                                Name);
   if (const Function *F = dyn_cast<Function>(StrCpy->stripPointerCasts()))
     CI->setCallingConv(F->getCallingConv());
   return CI;
 }

 /// EmitStrNCpy - Emit a call to the strncpy function to the builder, for the
 /// specified pointer arguments.
 Value *llvm::EmitStrNCpy(Value *Dst, Value *Src, Value *Len,
                          IRBuilder<> &B, const TargetData *TD, StringRef Name) {
   Module *M = B.GetInsertBlock()->getParent()->getParent();
   AttributeWithIndex AWI[2];
   AWI[0] = AttributeWithIndex::get(2, Attribute::NoCapture);
   AWI[1] = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
   Type *I8Ptr = B.getInt8PtrTy();
   Value *StrNCpy = M->getOrInsertFunction(Name, AttrListPtr::get(AWI, 2),
                                           I8Ptr, I8Ptr, I8Ptr,
                                           Len->getType(), NULL);
   CallInst *CI = B.CreateCall3(StrNCpy, CastToCStr(Dst, B), CastToCStr(Src, B),
                                Len, "strncpy");
   if (const Function *F = dyn_cast<Function>(StrNCpy->stripPointerCasts()))
     CI->setCallingConv(F->getCallingConv());
   return CI;
 }

 /// EmitMemCpyChk - Emit a call to the __memcpy_chk function to the builder.
 /// This expects that the Len and ObjSize have type 'intptr_t' and Dst/Src
 /// are pointers.
 Value *llvm::EmitMemCpyChk(Value *Dst, Value *Src, Value *Len, Value *ObjSize,
                            IRBuilder<> &B, const TargetData *TD) {
   Module *M = B.GetInsertBlock()->getParent()->getParent();
   AttributeWithIndex AWI;
   AWI = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
   LLVMContext &Context = B.GetInsertBlock()->getContext();
   Value *MemCpy = M->getOrInsertFunction("__memcpy_chk",
                                          AttrListPtr::get(&AWI, 1),
                                          B.getInt8PtrTy(),
                                          B.getInt8PtrTy(),
                                          B.getInt8PtrTy(),
                                          TD->getIntPtrType(Context),
                                          TD->getIntPtrType(Context), NULL);
   Dst = CastToCStr(Dst, B);
   Src = CastToCStr(Src, B);
   CallInst *CI = B.CreateCall4(MemCpy, Dst, Src, Len, ObjSize);
   if (const Function *F = dyn_cast<Function>(MemCpy->stripPointerCasts()))
     CI->setCallingConv(F->getCallingConv());
   return CI;
 }

 /// EmitMemChr - Emit a call to the memchr function.  This assumes that Ptr is
 /// a pointer, Val is an i32 value, and Len is an 'intptr_t' value.
 Value *llvm::EmitMemChr(Value *Ptr, Value *Val,
                         Value *Len, IRBuilder<> &B, const TargetData *TD) {
   Module *M = B.GetInsertBlock()->getParent()->getParent();
   AttributeWithIndex AWI;
   AWI = AttributeWithIndex::get(~0u, Attribute::ReadOnly | Attribute::NoUnwind);
   LLVMContext &Context = B.GetInsertBlock()->getContext();
   Value *MemChr = M->getOrInsertFunction("memchr", AttrListPtr::get(&AWI, 1),
                                          B.getInt8PtrTy(),
                                          B.getInt8PtrTy(),
                                          B.getInt32Ty(),
                                          TD->getIntPtrType(Context),
                                          NULL);
   CallInst *CI = B.CreateCall3(MemChr, CastToCStr(Ptr, B), Val, Len, "memchr");

   if (const Function *F = dyn_cast<Function>(MemChr->stripPointerCasts()))
     CI->setCallingConv(F->getCallingConv());

   return CI;
 }

 /// EmitMemCmp - Emit a call to the memcmp function.
 Value *llvm::EmitMemCmp(Value *Ptr1, Value *Ptr2,
                         Value *Len, IRBuilder<> &B, const TargetData *TD) {
   Module *M = B.GetInsertBlock()->getParent()->getParent();
   AttributeWithIndex AWI[3];
   AWI[0] = AttributeWithIndex::get(1, Attribute::NoCapture);
   AWI[1] = AttributeWithIndex::get(2, Attribute::NoCapture);
   AWI[2] = AttributeWithIndex::get(~0u, Attribute::ReadOnly |
                                    Attribute::NoUnwind);

   LLVMContext &Context = B.GetInsertBlock()->getContext();
   Value *MemCmp = M->getOrInsertFunction("memcmp", AttrListPtr::get(AWI, 3),
                                          B.getInt32Ty(),
                                          B.getInt8PtrTy(),
                                          B.getInt8PtrTy(),
                                          TD->getIntPtrType(Context), NULL);
   CallInst *CI = B.CreateCall3(MemCmp, CastToCStr(Ptr1, B), CastToCStr(Ptr2, B),
                                Len, "memcmp");

   if (const Function *F = dyn_cast<Function>(MemCmp->stripPointerCasts()))
     CI->setCallingConv(F->getCallingConv());

   return CI;
 }

 /// EmitUnaryFloatFnCall - Emit a call to the unary function named 'Name' (e.g.
 /// 'floor').  This function is known to take a single of type matching 'Op' and
 /// returns one value with the same type.  If 'Op' is a long double, 'l' is
 /// added as the suffix of name, if 'Op' is a float, we add a 'f' suffix.
 Value *llvm::EmitUnaryFloatFnCall(Value *Op, const char *Name,
                                   IRBuilder<> &B, const AttrListPtr &Attrs) {
   char NameBuffer[20];
   if (!Op->getType()->isDoubleTy()) {
     // If we need to add a suffix, copy into NameBuffer.
     unsigned NameLen = strlen(Name);
     assert(NameLen < sizeof(NameBuffer)-2);
     memcpy(NameBuffer, Name, NameLen);
     if (Op->getType()->isFloatTy())
       NameBuffer[NameLen] = 'f';  // floorf
     else
       NameBuffer[NameLen] = 'l';  // floorl
     NameBuffer[NameLen+1] = 0;
     Name = NameBuffer;
   }

   Module *M = B.GetInsertBlock()->getParent()->getParent();
   Value *Callee = M->getOrInsertFunction(Name, Op->getType(),
                                          Op->getType(), NULL);
   CallInst *CI = B.CreateCall(Callee, Op, Name);
   CI->setAttributes(Attrs);
   if (const Function *F = dyn_cast<Function>(Callee->stripPointerCasts()))
     CI->setCallingConv(F->getCallingConv());

   return CI;
 }

 /// EmitPutChar - Emit a call to the putchar function.  This assumes that Char
 /// is an integer.
 Value *llvm::EmitPutChar(Value *Char, IRBuilder<> &B, const TargetData *TD) {
   Module *M = B.GetInsertBlock()->getParent()->getParent();
   Value *PutChar = M->getOrInsertFunction("putchar", B.getInt32Ty(),
                                           B.getInt32Ty(), NULL);
   CallInst *CI = B.CreateCall(PutChar,
                               B.CreateIntCast(Char,
                               B.getInt32Ty(),
                               /*isSigned*/true,
                               "chari"),
                               "putchar");

   if (const Function *F = dyn_cast<Function>(PutChar->stripPointerCasts()))
     CI->setCallingConv(F->getCallingConv());
   return CI;
 }

 /// EmitPutS - Emit a call to the puts function.  This assumes that Str is
 /// some pointer.
 void llvm::EmitPutS(Value *Str, IRBuilder<> &B, const TargetData *TD) {
   Module *M = B.GetInsertBlock()->getParent()->getParent();
   AttributeWithIndex AWI[2];
   AWI[0] = AttributeWithIndex::get(1, Attribute::NoCapture);
   AWI[1] = AttributeWithIndex::get(~0u, Attribute::NoUnwind);

   Value *PutS = M->getOrInsertFunction("puts", AttrListPtr::get(AWI, 2),
                                        B.getInt32Ty(),
                                        B.getInt8PtrTy(),
                                        NULL);
   CallInst *CI = B.CreateCall(PutS, CastToCStr(Str, B), "puts");
   if (const Function *F = dyn_cast<Function>(PutS->stripPointerCasts()))
     CI->setCallingConv(F->getCallingConv());

 }

 /// EmitFPutC - Emit a call to the fputc function.  This assumes that Char is
 /// an integer and File is a pointer to FILE.
 void llvm::EmitFPutC(Value *Char, Value *File, IRBuilder<> &B,
                      const TargetData *TD) {
   Module *M = B.GetInsertBlock()->getParent()->getParent();
   AttributeWithIndex AWI[2];
   AWI[0] = AttributeWithIndex::get(2, Attribute::NoCapture);
   AWI[1] = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
   Constant *F;
   if (File->getType()->isPointerTy())
     F = M->getOrInsertFunction("fputc", AttrListPtr::get(AWI, 2),
                                B.getInt32Ty(),
                                B.getInt32Ty(), File->getType(),
                                NULL);
   else
     F = M->getOrInsertFunction("fputc",
                                B.getInt32Ty(),
                                B.getInt32Ty(),
                                File->getType(), NULL);
   Char = B.CreateIntCast(Char, B.getInt32Ty(), /*isSigned*/true,
                          "chari");
   CallInst *CI = B.CreateCall2(F, Char, File, "fputc");

   if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
     CI->setCallingConv(Fn->getCallingConv());
 }

 /// EmitFPutS - Emit a call to the puts function.  Str is required to be a
 /// pointer and File is a pointer to FILE.
 void llvm::EmitFPutS(Value *Str, Value *File, IRBuilder<> &B,
                      const TargetData *TD) {
   Module *M = B.GetInsertBlock()->getParent()->getParent();
   AttributeWithIndex AWI[3];
   AWI[0] = AttributeWithIndex::get(1, Attribute::NoCapture);
   AWI[1] = AttributeWithIndex::get(2, Attribute::NoCapture);
   AWI[2] = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
   Constant *F;
   if (File->getType()->isPointerTy())
     F = M->getOrInsertFunction("fputs", AttrListPtr::get(AWI, 3),
                                B.getInt32Ty(),
                                B.getInt8PtrTy(),
                                File->getType(), NULL);
   else
     F = M->getOrInsertFunction("fputs", B.getInt32Ty(),
                                B.getInt8PtrTy(),
                                File->getType(), NULL);
   CallInst *CI = B.CreateCall2(F, CastToCStr(Str, B), File, "fputs");

   if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
     CI->setCallingConv(Fn->getCallingConv());
 }

 /// EmitFWrite - Emit a call to the fwrite function.  This assumes that Ptr is
 /// a pointer, Size is an 'intptr_t', and File is a pointer to FILE.
 void llvm::EmitFWrite(Value *Ptr, Value *Size, Value *File,
                       IRBuilder<> &B, const TargetData *TD) {
   Module *M = B.GetInsertBlock()->getParent()->getParent();
   AttributeWithIndex AWI[3];
   AWI[0] = AttributeWithIndex::get(1, Attribute::NoCapture);
   AWI[1] = AttributeWithIndex::get(4, Attribute::NoCapture);
   AWI[2] = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
   LLVMContext &Context = B.GetInsertBlock()->getContext();
   Constant *F;
   if (File->getType()->isPointerTy())
     F = M->getOrInsertFunction("fwrite", AttrListPtr::get(AWI, 3),
                                TD->getIntPtrType(Context),
                                B.getInt8PtrTy(),
                                TD->getIntPtrType(Context),
                                TD->getIntPtrType(Context),
                                File->getType(), NULL);
   else
     F = M->getOrInsertFunction("fwrite", TD->getIntPtrType(Context),
                                B.getInt8PtrTy(),
                                TD->getIntPtrType(Context),
                                TD->getIntPtrType(Context),
                                File->getType(), NULL);
   CallInst *CI = B.CreateCall4(F, CastToCStr(Ptr, B), Size,
                         ConstantInt::get(TD->getIntPtrType(Context), 1), File);

   if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
     CI->setCallingConv(Fn->getCallingConv());
 }

 SimplifyFortifiedLibCalls::~SimplifyFortifiedLibCalls() { }

 bool SimplifyFortifiedLibCalls::fold(CallInst *CI, const TargetData *TD) {
   // We really need TargetData for later.
   if (!TD) return false;

   this->CI = CI;
   Function *Callee = CI->getCalledFunction();
   StringRef Name = Callee->getName();
   FunctionType *FT = Callee->getFunctionType();
   LLVMContext &Context = CI->getParent()->getContext();
   IRBuilder<> B(CI);

   if (Name == "__memcpy_chk") {
     // Check if this has the right signature.
     if (FT->getNumParams() != 4 || FT->getReturnType() != FT->getParamType(0) ||
         !FT->getParamType(0)->isPointerTy() ||
         !FT->getParamType(1)->isPointerTy() ||
         FT->getParamType(2) != TD->getIntPtrType(Context) ||
         FT->getParamType(3) != TD->getIntPtrType(Context))
       return false;

     if (isFoldable(3, 2, false)) {
       B.CreateMemCpy(CI->getArgOperand(0), CI->getArgOperand(1),
                      CI->getArgOperand(2), 1);
       replaceCall(CI->getArgOperand(0));
       return true;
     }
     return false;
   }

   // Should be similar to memcpy.
   if (Name == "__mempcpy_chk") {
     return false;
   }

   if (Name == "__memmove_chk") {
     // Check if this has the right signature.
     if (FT->getNumParams() != 4 || FT->getReturnType() != FT->getParamType(0) ||
         !FT->getParamType(0)->isPointerTy() ||
         !FT->getParamType(1)->isPointerTy() ||
         FT->getParamType(2) != TD->getIntPtrType(Context) ||
         FT->getParamType(3) != TD->getIntPtrType(Context))
       return false;

     if (isFoldable(3, 2, false)) {
       B.CreateMemMove(CI->getArgOperand(0), CI->getArgOperand(1),
                       CI->getArgOperand(2), 1);
       replaceCall(CI->getArgOperand(0));
       return true;
     }
     return false;
   }

   if (Name == "__memset_chk") {
     // Check if this has the right signature.
     if (FT->getNumParams() != 4 || FT->getReturnType() != FT->getParamType(0) ||
         !FT->getParamType(0)->isPointerTy() ||
         !FT->getParamType(1)->isIntegerTy() ||
         FT->getParamType(2) != TD->getIntPtrType(Context) ||
         FT->getParamType(3) != TD->getIntPtrType(Context))
       return false;

     if (isFoldable(3, 2, false)) {
       Value *Val = B.CreateIntCast(CI->getArgOperand(1), B.getInt8Ty(),
                                    false);
       B.CreateMemSet(CI->getArgOperand(0), Val, CI->getArgOperand(2), 1);
       replaceCall(CI->getArgOperand(0));
       return true;
     }
     return false;
   }

   if (Name == "__strcpy_chk" || Name == "__stpcpy_chk") {
     // Check if this has the right signature.
     if (FT->getNumParams() != 3 ||
         FT->getReturnType() != FT->getParamType(0) ||
         FT->getParamType(0) != FT->getParamType(1) ||
         FT->getParamType(0) != Type::getInt8PtrTy(Context) ||
         FT->getParamType(2) != TD->getIntPtrType(Context))
       return 0;


     // If a) we don't have any length information, or b) we know this will
     // fit then just lower to a plain st[rp]cpy. Otherwise we'll keep our
     // st[rp]cpy_chk call which may fail at runtime if the size is too long.
     // TODO: It might be nice to get a maximum length out of the possible
     // string lengths for varying.
     if (isFoldable(2, 1, true)) {
       Value *Ret = EmitStrCpy(CI->getArgOperand(0), CI->getArgOperand(1), B, TD,
                               Name.substr(2, 6));
       replaceCall(Ret);
       return true;
     }
     return false;
   }

   if (Name == "__strncpy_chk" || Name == "__stpncpy_chk") {
     // Check if this has the right signature.
     if (FT->getNumParams() != 4 || FT->getReturnType() != FT->getParamType(0) ||
         FT->getParamType(0) != FT->getParamType(1) ||
         FT->getParamType(0) != Type::getInt8PtrTy(Context) ||
         !FT->getParamType(2)->isIntegerTy() ||
         FT->getParamType(3) != TD->getIntPtrType(Context))
       return false;

     if (isFoldable(3, 2, false)) {
       Value *Ret = EmitStrNCpy(CI->getArgOperand(0), CI->getArgOperand(1),
                                CI->getArgOperand(2), B, TD, Name.substr(2, 7));
       replaceCall(Ret);
       return true;
     }
     return false;
   }

   if (Name == "__strcat_chk") {
     return false;
   }

   if (Name == "__strncat_chk") {
     return false;
   }

   return false;
 }
	//===- BuildLibCalls.cpp - Utility builder for libcalls -------------------===//
	//
	// The LLVM Compiler Infrastructure
	//
	// This file is distributed under the University of Illinois Open Source
	// License. See LICENSE.TXT for details.
	//
	//===----------------------------------------------------------------------===//
	//
	// This file implements some functions that will create standard C libcalls.
	//
	//===----------------------------------------------------------------------===//

	#include "llvm/Transforms/Utils/BuildLibCalls.h"
	#include "llvm/Type.h"
	#include "llvm/Constants.h"
	#include "llvm/Function.h"
	#include "llvm/Module.h"
	#include "llvm/Support/IRBuilder.h"
	#include "llvm/Target/TargetData.h"
	#include "llvm/LLVMContext.h"
	#include "llvm/Intrinsics.h"

	using namespace llvm;

	/// CastToCStr - Return V if it is an i8, otherwise cast it to i8.
	Value llvm::CastToCStr(Value V, IRBuilder<> &B) {
	return B.CreateBitCast(V, B.getInt8PtrTy(), "cstr");
	}

	/// EmitStrLen - Emit a call to the strlen function to the builder, for the
	/// specified pointer. This always returns an integer value of size intptr_t.
	Value llvm::EmitStrLen(Value Ptr, IRBuilder<> &B, const TargetData *TD) {
	Module *M = B.GetInsertBlock()->getParent()->getParent();
	AttributeWithIndex AWI[2];
	AWI[0] = AttributeWithIndex::get(1, Attribute::NoCapture);
	AWI[1] = AttributeWithIndex::get(~0u, Attribute::ReadOnly \|
	Attribute::NoUnwind);

	LLVMContext &Context = B.GetInsertBlock()->getContext();
	Constant *StrLen = M->getOrInsertFunction("strlen", AttrListPtr::get(AWI, 2),
	TD->getIntPtrType(Context),
	B.getInt8PtrTy(),
	NULL);
	CallInst *CI = B.CreateCall(StrLen, CastToCStr(Ptr, B), "strlen");
	if (const Function *F = dyn_cast<Function>(StrLen->stripPointerCasts()))
	CI->setCallingConv(F->getCallingConv());

	return CI;
	}

	/// EmitStrChr - Emit a call to the strchr function to the builder, for the
	/// specified pointer and character. Ptr is required to be some pointer type,
	/// and the return value has 'i8*' type.
	Value llvm::EmitStrChr(Value Ptr, char C, IRBuilder<> &B,
	const TargetData *TD) {
	Module *M = B.GetInsertBlock()->getParent()->getParent();
	AttributeWithIndex AWI =
	AttributeWithIndex::get(~0u, Attribute::ReadOnly \| Attribute::NoUnwind);

	Type *I8Ptr = B.getInt8PtrTy();
	Type *I32Ty = B.getInt32Ty();
	Constant *StrChr = M->getOrInsertFunction("strchr", AttrListPtr::get(&AWI, 1),
	I8Ptr, I8Ptr, I32Ty, NULL);
	CallInst *CI = B.CreateCall2(StrChr, CastToCStr(Ptr, B),
	ConstantInt::get(I32Ty, C), "strchr");
	if (const Function *F = dyn_cast<Function>(StrChr->stripPointerCasts()))
	CI->setCallingConv(F->getCallingConv());
	return CI;
	}

	/// EmitStrNCmp - Emit a call to the strncmp function to the builder.
	Value llvm::EmitStrNCmp(Value Ptr1, Value Ptr2, Value Len,
	IRBuilder<> &B, const TargetData *TD) {
	Module *M = B.GetInsertBlock()->getParent()->getParent();
	AttributeWithIndex AWI[3];
	AWI[0] = AttributeWithIndex::get(1, Attribute::NoCapture);
	AWI[1] = AttributeWithIndex::get(2, Attribute::NoCapture);
	AWI[2] = AttributeWithIndex::get(~0u, Attribute::ReadOnly \|
	Attribute::NoUnwind);

	LLVMContext &Context = B.GetInsertBlock()->getContext();
	Value *StrNCmp = M->getOrInsertFunction("strncmp", AttrListPtr::get(AWI, 3),
	B.getInt32Ty(),
	B.getInt8PtrTy(),
	B.getInt8PtrTy(),
	TD->getIntPtrType(Context), NULL);
	CallInst *CI = B.CreateCall3(StrNCmp, CastToCStr(Ptr1, B),
	CastToCStr(Ptr2, B), Len, "strncmp");

	if (const Function *F = dyn_cast<Function>(StrNCmp->stripPointerCasts()))
	CI->setCallingConv(F->getCallingConv());

	return CI;
	}

	/// EmitStrCpy - Emit a call to the strcpy function to the builder, for the
	/// specified pointer arguments.
	Value llvm::EmitStrCpy(Value Dst, Value *Src, IRBuilder<> &B,
	const TargetData *TD, StringRef Name) {
	Module *M = B.GetInsertBlock()->getParent()->getParent();
	AttributeWithIndex AWI[2];
	AWI[0] = AttributeWithIndex::get(2, Attribute::NoCapture);
	AWI[1] = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
	Type *I8Ptr = B.getInt8PtrTy();
	Value *StrCpy = M->getOrInsertFunction(Name, AttrListPtr::get(AWI, 2),
	I8Ptr, I8Ptr, I8Ptr, NULL);
	CallInst *CI = B.CreateCall2(StrCpy, CastToCStr(Dst, B), CastToCStr(Src, B),
	Name);
	if (const Function *F = dyn_cast<Function>(StrCpy->stripPointerCasts()))
	CI->setCallingConv(F->getCallingConv());
	return CI;
	}

	/// EmitStrNCpy - Emit a call to the strncpy function to the builder, for the
	/// specified pointer arguments.
	Value llvm::EmitStrNCpy(Value Dst, Value Src, Value Len,
	IRBuilder<> &B, const TargetData *TD, StringRef Name) {
	Module *M = B.GetInsertBlock()->getParent()->getParent();
	AttributeWithIndex AWI[2];
	AWI[0] = AttributeWithIndex::get(2, Attribute::NoCapture);
	AWI[1] = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
	Type *I8Ptr = B.getInt8PtrTy();
	Value *StrNCpy = M->getOrInsertFunction(Name, AttrListPtr::get(AWI, 2),
	I8Ptr, I8Ptr, I8Ptr,
	Len->getType(), NULL);
	CallInst *CI = B.CreateCall3(StrNCpy, CastToCStr(Dst, B), CastToCStr(Src, B),
	Len, "strncpy");
	if (const Function *F = dyn_cast<Function>(StrNCpy->stripPointerCasts()))
	CI->setCallingConv(F->getCallingConv());
	return CI;
	}

	/// EmitMemCpyChk - Emit a call to the __memcpy_chk function to the builder.
	/// This expects that the Len and ObjSize have type 'intptr_t' and Dst/Src
	/// are pointers.
	Value llvm::EmitMemCpyChk(Value Dst, Value Src, Value Len, Value *ObjSize,
	IRBuilder<> &B, const TargetData *TD) {
	Module *M = B.GetInsertBlock()->getParent()->getParent();
	AttributeWithIndex AWI;
	AWI = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
	LLVMContext &Context = B.GetInsertBlock()->getContext();
	Value *MemCpy = M->getOrInsertFunction("__memcpy_chk",
	AttrListPtr::get(&AWI, 1),
	B.getInt8PtrTy(),
	B.getInt8PtrTy(),
	B.getInt8PtrTy(),
	TD->getIntPtrType(Context),
	TD->getIntPtrType(Context), NULL);
	Dst = CastToCStr(Dst, B);
	Src = CastToCStr(Src, B);
	CallInst *CI = B.CreateCall4(MemCpy, Dst, Src, Len, ObjSize);
	if (const Function *F = dyn_cast<Function>(MemCpy->stripPointerCasts()))
	CI->setCallingConv(F->getCallingConv());
	return CI;
	}

	/// EmitMemChr - Emit a call to the memchr function. This assumes that Ptr is
	/// a pointer, Val is an i32 value, and Len is an 'intptr_t' value.
	Value llvm::EmitMemChr(Value Ptr, Value *Val,
	Value Len, IRBuilder<> &B, const TargetData TD) {
	Module *M = B.GetInsertBlock()->getParent()->getParent();
	AttributeWithIndex AWI;
	AWI = AttributeWithIndex::get(~0u, Attribute::ReadOnly \| Attribute::NoUnwind);
	LLVMContext &Context = B.GetInsertBlock()->getContext();
	Value *MemChr = M->getOrInsertFunction("memchr", AttrListPtr::get(&AWI, 1),
	B.getInt8PtrTy(),
	B.getInt8PtrTy(),
	B.getInt32Ty(),
	TD->getIntPtrType(Context),
	NULL);
	CallInst *CI = B.CreateCall3(MemChr, CastToCStr(Ptr, B), Val, Len, "memchr");

	if (const Function *F = dyn_cast<Function>(MemChr->stripPointerCasts()))
	CI->setCallingConv(F->getCallingConv());

	return CI;
	}

	/// EmitMemCmp - Emit a call to the memcmp function.
	Value llvm::EmitMemCmp(Value Ptr1, Value *Ptr2,
	Value Len, IRBuilder<> &B, const TargetData TD) {
	Module *M = B.GetInsertBlock()->getParent()->getParent();
	AttributeWithIndex AWI[3];
	AWI[0] = AttributeWithIndex::get(1, Attribute::NoCapture);
	AWI[1] = AttributeWithIndex::get(2, Attribute::NoCapture);
	AWI[2] = AttributeWithIndex::get(~0u, Attribute::ReadOnly \|
	Attribute::NoUnwind);

	LLVMContext &Context = B.GetInsertBlock()->getContext();
	Value *MemCmp = M->getOrInsertFunction("memcmp", AttrListPtr::get(AWI, 3),
	B.getInt32Ty(),
	B.getInt8PtrTy(),
	B.getInt8PtrTy(),
	TD->getIntPtrType(Context), NULL);
	CallInst *CI = B.CreateCall3(MemCmp, CastToCStr(Ptr1, B), CastToCStr(Ptr2, B),
	Len, "memcmp");

	if (const Function *F = dyn_cast<Function>(MemCmp->stripPointerCasts()))
	CI->setCallingConv(F->getCallingConv());

	return CI;
	}

	/// EmitUnaryFloatFnCall - Emit a call to the unary function named 'Name' (e.g.
	/// 'floor'). This function is known to take a single of type matching 'Op' and
	/// returns one value with the same type. If 'Op' is a long double, 'l' is
	/// added as the suffix of name, if 'Op' is a float, we add a 'f' suffix.
	Value llvm::EmitUnaryFloatFnCall(Value Op, const char *Name,
	IRBuilder<> &B, const AttrListPtr &Attrs) {
	char NameBuffer[20];
	if (!Op->getType()->isDoubleTy()) {
	// If we need to add a suffix, copy into NameBuffer.
	unsigned NameLen = strlen(Name);
	assert(NameLen < sizeof(NameBuffer)-2);
	memcpy(NameBuffer, Name, NameLen);
	if (Op->getType()->isFloatTy())
	NameBuffer[NameLen] = 'f'; // floorf
	else
	NameBuffer[NameLen] = 'l'; // floorl
	NameBuffer[NameLen+1] = 0;
	Name = NameBuffer;
	}

	Module *M = B.GetInsertBlock()->getParent()->getParent();
	Value *Callee = M->getOrInsertFunction(Name, Op->getType(),
	Op->getType(), NULL);
	CallInst *CI = B.CreateCall(Callee, Op, Name);
	CI->setAttributes(Attrs);
	if (const Function *F = dyn_cast<Function>(Callee->stripPointerCasts()))
	CI->setCallingConv(F->getCallingConv());

	return CI;
	}

	/// EmitPutChar - Emit a call to the putchar function. This assumes that Char
	/// is an integer.
	Value llvm::EmitPutChar(Value Char, IRBuilder<> &B, const TargetData *TD) {
	Module *M = B.GetInsertBlock()->getParent()->getParent();
	Value *PutChar = M->getOrInsertFunction("putchar", B.getInt32Ty(),
	B.getInt32Ty(), NULL);
	CallInst *CI = B.CreateCall(PutChar,
	B.CreateIntCast(Char,
	B.getInt32Ty(),
	/isSigned/true,
	"chari"),
	"putchar");

	if (const Function *F = dyn_cast<Function>(PutChar->stripPointerCasts()))
	CI->setCallingConv(F->getCallingConv());
	return CI;
	}

	/// EmitPutS - Emit a call to the puts function. This assumes that Str is
	/// some pointer.
	void llvm::EmitPutS(Value Str, IRBuilder<> &B, const TargetData TD) {
	Module *M = B.GetInsertBlock()->getParent()->getParent();
	AttributeWithIndex AWI[2];
	AWI[0] = AttributeWithIndex::get(1, Attribute::NoCapture);
	AWI[1] = AttributeWithIndex::get(~0u, Attribute::NoUnwind);

	Value *PutS = M->getOrInsertFunction("puts", AttrListPtr::get(AWI, 2),
	B.getInt32Ty(),
	B.getInt8PtrTy(),
	NULL);
	CallInst *CI = B.CreateCall(PutS, CastToCStr(Str, B), "puts");
	if (const Function *F = dyn_cast<Function>(PutS->stripPointerCasts()))
	CI->setCallingConv(F->getCallingConv());

	}

	/// EmitFPutC - Emit a call to the fputc function. This assumes that Char is
	/// an integer and File is a pointer to FILE.
	void llvm::EmitFPutC(Value Char, Value File, IRBuilder<> &B,
	const TargetData *TD) {
	Module *M = B.GetInsertBlock()->getParent()->getParent();
	AttributeWithIndex AWI[2];
	AWI[0] = AttributeWithIndex::get(2, Attribute::NoCapture);
	AWI[1] = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
	Constant *F;
	if (File->getType()->isPointerTy())
	F = M->getOrInsertFunction("fputc", AttrListPtr::get(AWI, 2),
	B.getInt32Ty(),
	B.getInt32Ty(), File->getType(),
	NULL);
	else
	F = M->getOrInsertFunction("fputc",
	B.getInt32Ty(),
	B.getInt32Ty(),
	File->getType(), NULL);
	Char = B.CreateIntCast(Char, B.getInt32Ty(), /isSigned/true,
	"chari");
	CallInst *CI = B.CreateCall2(F, Char, File, "fputc");

	if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
	CI->setCallingConv(Fn->getCallingConv());
	}

	/// EmitFPutS - Emit a call to the puts function. Str is required to be a
	/// pointer and File is a pointer to FILE.
	void llvm::EmitFPutS(Value Str, Value File, IRBuilder<> &B,
	const TargetData *TD) {
	Module *M = B.GetInsertBlock()->getParent()->getParent();
	AttributeWithIndex AWI[3];
	AWI[0] = AttributeWithIndex::get(1, Attribute::NoCapture);
	AWI[1] = AttributeWithIndex::get(2, Attribute::NoCapture);
	AWI[2] = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
	Constant *F;
	if (File->getType()->isPointerTy())
	F = M->getOrInsertFunction("fputs", AttrListPtr::get(AWI, 3),
	B.getInt32Ty(),
	B.getInt8PtrTy(),
	File->getType(), NULL);
	else
	F = M->getOrInsertFunction("fputs", B.getInt32Ty(),
	B.getInt8PtrTy(),
	File->getType(), NULL);
	CallInst *CI = B.CreateCall2(F, CastToCStr(Str, B), File, "fputs");

	if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
	CI->setCallingConv(Fn->getCallingConv());
	}

	/// EmitFWrite - Emit a call to the fwrite function. This assumes that Ptr is
	/// a pointer, Size is an 'intptr_t', and File is a pointer to FILE.
	void llvm::EmitFWrite(Value Ptr, Value Size, Value *File,
	IRBuilder<> &B, const TargetData *TD) {
	Module *M = B.GetInsertBlock()->getParent()->getParent();
	AttributeWithIndex AWI[3];
	AWI[0] = AttributeWithIndex::get(1, Attribute::NoCapture);
	AWI[1] = AttributeWithIndex::get(4, Attribute::NoCapture);
	AWI[2] = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
	LLVMContext &Context = B.GetInsertBlock()->getContext();
	Constant *F;
	if (File->getType()->isPointerTy())
	F = M->getOrInsertFunction("fwrite", AttrListPtr::get(AWI, 3),
	TD->getIntPtrType(Context),
	B.getInt8PtrTy(),
	TD->getIntPtrType(Context),
	TD->getIntPtrType(Context),
	File->getType(), NULL);
	else
	F = M->getOrInsertFunction("fwrite", TD->getIntPtrType(Context),
	B.getInt8PtrTy(),
	TD->getIntPtrType(Context),
	TD->getIntPtrType(Context),
	File->getType(), NULL);
	CallInst *CI = B.CreateCall4(F, CastToCStr(Ptr, B), Size,
	ConstantInt::get(TD->getIntPtrType(Context), 1), File);

	if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
	CI->setCallingConv(Fn->getCallingConv());
	}

	SimplifyFortifiedLibCalls::~SimplifyFortifiedLibCalls() { }

	bool SimplifyFortifiedLibCalls::fold(CallInst CI, const TargetData TD) {
	// We really need TargetData for later.
	if (!TD) return false;

	this->CI = CI;
	Function *Callee = CI->getCalledFunction();
	StringRef Name = Callee->getName();
	FunctionType *FT = Callee->getFunctionType();
	LLVMContext &Context = CI->getParent()->getContext();
	IRBuilder<> B(CI);

	if (Name == "__memcpy_chk") {
	// Check if this has the right signature.
	if (FT->getNumParams() != 4 \|\| FT->getReturnType() != FT->getParamType(0) \|\|
	!FT->getParamType(0)->isPointerTy() \|\|
	!FT->getParamType(1)->isPointerTy() \|\|
	FT->getParamType(2) != TD->getIntPtrType(Context) \|\|
	FT->getParamType(3) != TD->getIntPtrType(Context))
	return false;

	if (isFoldable(3, 2, false)) {
	B.CreateMemCpy(CI->getArgOperand(0), CI->getArgOperand(1),
	CI->getArgOperand(2), 1);
	replaceCall(CI->getArgOperand(0));
	return true;
	}
	return false;
	}

	// Should be similar to memcpy.
	if (Name == "__mempcpy_chk") {
	return false;
	}

	if (Name == "__memmove_chk") {
	// Check if this has the right signature.
	if (FT->getNumParams() != 4 \|\| FT->getReturnType() != FT->getParamType(0) \|\|
	!FT->getParamType(0)->isPointerTy() \|\|
	!FT->getParamType(1)->isPointerTy() \|\|
	FT->getParamType(2) != TD->getIntPtrType(Context) \|\|
	FT->getParamType(3) != TD->getIntPtrType(Context))
	return false;

	if (isFoldable(3, 2, false)) {
	B.CreateMemMove(CI->getArgOperand(0), CI->getArgOperand(1),
	CI->getArgOperand(2), 1);
	replaceCall(CI->getArgOperand(0));
	return true;
	}
	return false;
	}

	if (Name == "__memset_chk") {
	// Check if this has the right signature.
	if (FT->getNumParams() != 4 \|\| FT->getReturnType() != FT->getParamType(0) \|\|
	!FT->getParamType(0)->isPointerTy() \|\|
	!FT->getParamType(1)->isIntegerTy() \|\|
	FT->getParamType(2) != TD->getIntPtrType(Context) \|\|
	FT->getParamType(3) != TD->getIntPtrType(Context))
	return false;

	if (isFoldable(3, 2, false)) {
	Value *Val = B.CreateIntCast(CI->getArgOperand(1), B.getInt8Ty(),
	false);
	B.CreateMemSet(CI->getArgOperand(0), Val, CI->getArgOperand(2), 1);
	replaceCall(CI->getArgOperand(0));
	return true;
	}
	return false;
	}

	if (Name == "__strcpy_chk" \|\| Name == "__stpcpy_chk") {
	// Check if this has the right signature.
	if (FT->getNumParams() != 3 \|\|
	FT->getReturnType() != FT->getParamType(0) \|\|
	FT->getParamType(0) != FT->getParamType(1) \|\|
	FT->getParamType(0) != Type::getInt8PtrTy(Context) \|\|
	FT->getParamType(2) != TD->getIntPtrType(Context))
	return 0;


	// If a) we don't have any length information, or b) we know this will
	// fit then just lower to a plain st[rp]cpy. Otherwise we'll keep our
	// st[rp]cpy_chk call which may fail at runtime if the size is too long.
	// TODO: It might be nice to get a maximum length out of the possible
	// string lengths for varying.
	if (isFoldable(2, 1, true)) {
	Value *Ret = EmitStrCpy(CI->getArgOperand(0), CI->getArgOperand(1), B, TD,
	Name.substr(2, 6));
	replaceCall(Ret);
	return true;
	}
	return false;
	}

	if (Name == "__strncpy_chk" \|\| Name == "__stpncpy_chk") {
	// Check if this has the right signature.
	if (FT->getNumParams() != 4 \|\| FT->getReturnType() != FT->getParamType(0) \|\|
	FT->getParamType(0) != FT->getParamType(1) \|\|
	FT->getParamType(0) != Type::getInt8PtrTy(Context) \|\|
	!FT->getParamType(2)->isIntegerTy() \|\|
	FT->getParamType(3) != TD->getIntPtrType(Context))
	return false;

	if (isFoldable(3, 2, false)) {
	Value *Ret = EmitStrNCpy(CI->getArgOperand(0), CI->getArgOperand(1),
	CI->getArgOperand(2), B, TD, Name.substr(2, 7));
	replaceCall(Ret);
	return true;
	}
	return false;
	}

	if (Name == "__strcat_chk") {
	return false;
	}

	if (Name == "__strncat_chk") {
	return false;
	}

	return false;
	}