SizeOffsetType ObjectSizeOffsetVisitor::visitCallSite(CallSite CS) {
Optional<AllocFnsTy> FnData = getAllocationSize(CS.getInstruction(), TLI);
if (!FnData)
return unknown();
// Handle strdup-like functions separately.
if (FnData->AllocTy == StrDupLike) {
APInt Size(IntTyBits, GetStringLength(CS.getArgument(0)));
if (!Size)
return unknown();
// Strndup limits strlen.
if (FnData->FstParam > 0) {
ConstantInt *Arg =
dyn_cast<ConstantInt>(CS.getArgument(FnData->FstParam));
if (!Arg)
return unknown();
APInt MaxSize = Arg->getValue().zextOrSelf(IntTyBits);
if (Size.ugt(MaxSize))
Size = MaxSize + 1;
}
return std::make_pair(Size, Zero);
}
ConstantInt *Arg = dyn_cast<ConstantInt>(CS.getArgument(FnData->FstParam));
if (!Arg)
return unknown();
APInt Size = Arg->getValue();
if (!CheckedZextOrTrunc(Size))
return unknown();
// Size is determined by just 1 parameter.
if (FnData->SndParam < 0)
return std::make_pair(Size, Zero);
Arg = dyn_cast<ConstantInt>(CS.getArgument(FnData->SndParam));
if (!Arg)
return unknown();
APInt NumElems = Arg->getValue();
if (!CheckedZextOrTrunc(NumElems))
return unknown();
bool Overflow;
Size = Size.umul_ov(NumElems, Overflow);
return Overflow ? unknown() : std::make_pair(Size, Zero);
// TODO: handle more standard functions (+ wchar cousins):
// - strdup / strndup
// - strcpy / strncpy
// - strcat / strncat
// - memcpy / memmove
// - strcat / strncat
// - memset
}
APInt swift::constantFoldBinaryWithOverflow(APInt lhs, APInt rhs,
bool &Overflow,
llvm::Intrinsic::ID ID) {
switch (ID) {
default: llvm_unreachable("Invalid case");
case llvm::Intrinsic::sadd_with_overflow:
return lhs.sadd_ov(rhs, Overflow);
case llvm::Intrinsic::uadd_with_overflow:
return lhs.uadd_ov(rhs, Overflow);
case llvm::Intrinsic::ssub_with_overflow:
return lhs.ssub_ov(rhs, Overflow);
case llvm::Intrinsic::usub_with_overflow:
return lhs.usub_ov(rhs, Overflow);
case llvm::Intrinsic::smul_with_overflow:
return lhs.smul_ov(rhs, Overflow);
case llvm::Intrinsic::umul_with_overflow:
return lhs.umul_ov(rhs, Overflow);
}
}
SizeOffsetType ObjectSizeOffsetVisitor::visitCallSite(CallSite CS) {
Optional<AllocFnsTy> FnData = getAllocationSize(CS.getInstruction(), TLI);
if (!FnData)
return unknown();
// Handle strdup-like functions separately.
if (FnData->AllocTy == StrDupLike) {
APInt Size(IntTyBits, GetStringLength(CS.getArgument(0)));
if (!Size)
return unknown();
// Strndup limits strlen.
if (FnData->FstParam > 0) {
ConstantInt *Arg =
dyn_cast<ConstantInt>(CS.getArgument(FnData->FstParam));
if (!Arg)
return unknown();
APInt MaxSize = Arg->getValue().zextOrSelf(IntTyBits);
if (Size.ugt(MaxSize))
Size = MaxSize + 1;
}
return std::make_pair(Size, Zero);
}
ConstantInt *Arg = dyn_cast<ConstantInt>(CS.getArgument(FnData->FstParam));
if (!Arg)
return unknown();
// When we're compiling N-bit code, and the user uses parameters that are
// greater than N bits (e.g. uint64_t on a 32-bit build), we can run into
// trouble with APInt size issues. This function handles resizing + overflow
// checks for us.
auto CheckedZextOrTrunc = [&](APInt &I) {
// More bits than we can handle. Checking the bit width isn't necessary, but
// it's faster than checking active bits, and should give `false` in the
// vast majority of cases.
if (I.getBitWidth() > IntTyBits && I.getActiveBits() > IntTyBits)
return false;
if (I.getBitWidth() != IntTyBits)
I = I.zextOrTrunc(IntTyBits);
return true;
};
APInt Size = Arg->getValue();
if (!CheckedZextOrTrunc(Size))
return unknown();
// Size is determined by just 1 parameter.
if (FnData->SndParam < 0)
return std::make_pair(Size, Zero);
Arg = dyn_cast<ConstantInt>(CS.getArgument(FnData->SndParam));
if (!Arg)
return unknown();
APInt NumElems = Arg->getValue();
if (!CheckedZextOrTrunc(NumElems))
return unknown();
bool Overflow;
Size = Size.umul_ov(NumElems, Overflow);
return Overflow ? unknown() : std::make_pair(Size, Zero);
// TODO: handle more standard functions (+ wchar cousins):
// - strdup / strndup
// - strcpy / strncpy
// - strcat / strncat
// - memcpy / memmove
// - strcat / strncat
// - memset
}