//===- 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/Intrinsics.h"
#include "llvm/LLVMContext.h"
#include "llvm/Module.h"
#include "llvm/Support/IRBuilder.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetLibraryInfo.h"
#include "llvm/LLVMContext.h"
#include "llvm/Intrinsics.h"
#include "llvm/ADT/SmallString.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, StringRef Name, IRBuilder<> &B,
const AttrListPtr &Attrs) {
SmallString<20> NameBuffer;
if (!Op->getType()->isDoubleTy()) {
// If we need to add a suffix, copy into NameBuffer.
NameBuffer += Name;
if (Op->getType()->isFloatTy())
NameBuffer += 'f'; // floorf
else
NameBuffer += 'l'; // floorl
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, const TargetLibraryInfo *TLI) {
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);
StringRef FPutsName = TLI->getName(LibFunc::fputs);
Constant *F;
if (File->getType()->isPointerTy())
F = M->getOrInsertFunction(FPutsName, AttrListPtr::get(AWI, 3),
B.getInt32Ty(),
B.getInt8PtrTy(),
File->getType(), NULL);
else
F = M->getOrInsertFunction(FPutsName, 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,
const TargetLibraryInfo *TLI) {
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();
StringRef FWriteName = TLI->getName(LibFunc::fwrite);
Constant *F;
if (File->getType()->isPointerTy())
F = M->getOrInsertFunction(FWriteName, AttrListPtr::get(AWI, 3),
TD->getIntPtrType(Context),
B.getInt8PtrTy(),
TD->getIntPtrType(Context),
TD->getIntPtrType(Context),
File->getType(), NULL);
else
F = M->getOrInsertFunction(FWriteName, 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;
}