llvm-project/llvm/lib/VMCore/Attributes.cpp

548 lines
19 KiB
C++

//===-- Attributes.cpp - Implement AttributesList -------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the Attributes, AttributeImpl, AttrBuilder,
// AttributeListImpl, and AttributeSet classes.
//
//===----------------------------------------------------------------------===//
#include "llvm/Attributes.h"
#include "AttributesImpl.h"
#include "LLVMContextImpl.h"
#include "llvm/ADT/FoldingSet.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/Support/Atomic.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/Mutex.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Type.h"
using namespace llvm;
//===----------------------------------------------------------------------===//
// Attributes Implementation
//===----------------------------------------------------------------------===//
Attributes Attributes::get(LLVMContext &Context, ArrayRef<AttrVal> Vals) {
AttrBuilder B;
for (ArrayRef<AttrVal>::iterator I = Vals.begin(), E = Vals.end();
I != E; ++I)
B.addAttribute(*I);
return Attributes::get(Context, B);
}
Attributes Attributes::get(LLVMContext &Context, AttrBuilder &B) {
// If there are no attributes, return an empty Attributes class.
if (!B.hasAttributes())
return Attributes();
// Otherwise, build a key to look up the existing attributes.
LLVMContextImpl *pImpl = Context.pImpl;
FoldingSetNodeID ID;
ID.AddInteger(B.Raw());
void *InsertPoint;
AttributesImpl *PA = pImpl->AttrsSet.FindNodeOrInsertPos(ID, InsertPoint);
if (!PA) {
// If we didn't find any existing attributes of the same shape then create a
// new one and insert it.
PA = new AttributesImpl(B.Raw());
pImpl->AttrsSet.InsertNode(PA, InsertPoint);
}
// Return the AttributesList that we found or created.
return Attributes(PA);
}
bool Attributes::hasAttribute(AttrVal Val) const {
return Attrs && Attrs->hasAttribute(Val);
}
bool Attributes::hasAttributes() const {
return Attrs && Attrs->hasAttributes();
}
bool Attributes::hasAttributes(const Attributes &A) const {
return Attrs && Attrs->hasAttributes(A);
}
/// This returns the alignment field of an attribute as a byte alignment value.
unsigned Attributes::getAlignment() const {
if (!hasAttribute(Attributes::Alignment))
return 0;
return 1U << ((Attrs->getAlignment() >> 16) - 1);
}
/// This returns the stack alignment field of an attribute as a byte alignment
/// value.
unsigned Attributes::getStackAlignment() const {
if (!hasAttribute(Attributes::StackAlignment))
return 0;
return 1U << ((Attrs->getStackAlignment() >> 26) - 1);
}
uint64_t Attributes::Raw() const {
return Attrs ? Attrs->Raw() : 0;
}
Attributes Attributes::typeIncompatible(Type *Ty) {
AttrBuilder Incompatible;
if (!Ty->isIntegerTy())
// Attributes that only apply to integers.
Incompatible.addAttribute(Attributes::SExt)
.addAttribute(Attributes::ZExt);
if (!Ty->isPointerTy())
// Attributes that only apply to pointers.
Incompatible.addAttribute(Attributes::ByVal)
.addAttribute(Attributes::Nest)
.addAttribute(Attributes::NoAlias)
.addAttribute(Attributes::NoCapture)
.addAttribute(Attributes::StructRet);
return Attributes::get(Ty->getContext(), Incompatible);
}
/// encodeLLVMAttributesForBitcode - This returns an integer containing an
/// encoding of all the LLVM attributes found in the given attribute bitset.
/// Any change to this encoding is a breaking change to bitcode compatibility.
uint64_t Attributes::encodeLLVMAttributesForBitcode(Attributes Attrs) {
// FIXME: It doesn't make sense to store the alignment information as an
// expanded out value, we should store it as a log2 value. However, we can't
// just change that here without breaking bitcode compatibility. If this ever
// becomes a problem in practice, we should introduce new tag numbers in the
// bitcode file and have those tags use a more efficiently encoded alignment
// field.
// Store the alignment in the bitcode as a 16-bit raw value instead of a 5-bit
// log2 encoded value. Shift the bits above the alignment up by 11 bits.
uint64_t EncodedAttrs = Attrs.Raw() & 0xffff;
if (Attrs.hasAttribute(Attributes::Alignment))
EncodedAttrs |= Attrs.getAlignment() << 16;
EncodedAttrs |= (Attrs.Raw() & (0xffffULL << 21)) << 11;
return EncodedAttrs;
}
/// decodeLLVMAttributesForBitcode - This returns an attribute bitset containing
/// the LLVM attributes that have been decoded from the given integer. This
/// function must stay in sync with 'encodeLLVMAttributesForBitcode'.
Attributes Attributes::decodeLLVMAttributesForBitcode(LLVMContext &C,
uint64_t EncodedAttrs) {
// The alignment is stored as a 16-bit raw value from bits 31--16. We shift
// the bits above 31 down by 11 bits.
unsigned Alignment = (EncodedAttrs & (0xffffULL << 16)) >> 16;
assert((!Alignment || isPowerOf2_32(Alignment)) &&
"Alignment must be a power of two.");
AttrBuilder B(EncodedAttrs & 0xffff);
if (Alignment)
B.addAlignmentAttr(Alignment);
B.addRawValue((EncodedAttrs & (0xffffULL << 32)) >> 11);
return Attributes::get(C, B);
}
std::string Attributes::getAsString() const {
std::string Result;
if (hasAttribute(Attributes::ZExt))
Result += "zeroext ";
if (hasAttribute(Attributes::SExt))
Result += "signext ";
if (hasAttribute(Attributes::NoReturn))
Result += "noreturn ";
if (hasAttribute(Attributes::NoUnwind))
Result += "nounwind ";
if (hasAttribute(Attributes::UWTable))
Result += "uwtable ";
if (hasAttribute(Attributes::ReturnsTwice))
Result += "returns_twice ";
if (hasAttribute(Attributes::InReg))
Result += "inreg ";
if (hasAttribute(Attributes::NoAlias))
Result += "noalias ";
if (hasAttribute(Attributes::NoCapture))
Result += "nocapture ";
if (hasAttribute(Attributes::StructRet))
Result += "sret ";
if (hasAttribute(Attributes::ByVal))
Result += "byval ";
if (hasAttribute(Attributes::Nest))
Result += "nest ";
if (hasAttribute(Attributes::ReadNone))
Result += "readnone ";
if (hasAttribute(Attributes::ReadOnly))
Result += "readonly ";
if (hasAttribute(Attributes::OptimizeForSize))
Result += "optsize ";
if (hasAttribute(Attributes::NoInline))
Result += "noinline ";
if (hasAttribute(Attributes::InlineHint))
Result += "inlinehint ";
if (hasAttribute(Attributes::AlwaysInline))
Result += "alwaysinline ";
if (hasAttribute(Attributes::StackProtect))
Result += "ssp ";
if (hasAttribute(Attributes::StackProtectReq))
Result += "sspreq ";
if (hasAttribute(Attributes::NoRedZone))
Result += "noredzone ";
if (hasAttribute(Attributes::NoImplicitFloat))
Result += "noimplicitfloat ";
if (hasAttribute(Attributes::Naked))
Result += "naked ";
if (hasAttribute(Attributes::NonLazyBind))
Result += "nonlazybind ";
if (hasAttribute(Attributes::AddressSafety))
Result += "address_safety ";
if (hasAttribute(Attributes::MinSize))
Result += "minsize ";
if (hasAttribute(Attributes::StackAlignment)) {
Result += "alignstack(";
Result += utostr(getStackAlignment());
Result += ") ";
}
if (hasAttribute(Attributes::Alignment)) {
Result += "align ";
Result += utostr(getAlignment());
Result += " ";
}
// Trim the trailing space.
assert(!Result.empty() && "Unknown attribute!");
Result.erase(Result.end()-1);
return Result;
}
//===----------------------------------------------------------------------===//
// AttrBuilder Implementation
//===----------------------------------------------------------------------===//
AttrBuilder &AttrBuilder::addAttribute(Attributes::AttrVal Val){
Bits |= AttributesImpl::getAttrMask(Val);
return *this;
}
AttrBuilder &AttrBuilder::addRawValue(uint64_t Val) {
Bits |= Val;
return *this;
}
AttrBuilder &AttrBuilder::addAlignmentAttr(unsigned Align) {
if (Align == 0) return *this;
assert(isPowerOf2_32(Align) && "Alignment must be a power of two.");
assert(Align <= 0x40000000 && "Alignment too large.");
Bits |= (Log2_32(Align) + 1) << 16;
return *this;
}
AttrBuilder &AttrBuilder::addStackAlignmentAttr(unsigned Align){
// Default alignment, allow the target to define how to align it.
if (Align == 0) return *this;
assert(isPowerOf2_32(Align) && "Alignment must be a power of two.");
assert(Align <= 0x100 && "Alignment too large.");
Bits |= (Log2_32(Align) + 1) << 26;
return *this;
}
AttrBuilder &AttrBuilder::removeAttribute(Attributes::AttrVal Val) {
Bits &= ~AttributesImpl::getAttrMask(Val);
return *this;
}
AttrBuilder &AttrBuilder::addAttributes(const Attributes &A) {
Bits |= A.Raw();
return *this;
}
AttrBuilder &AttrBuilder::removeAttributes(const Attributes &A){
Bits &= ~A.Raw();
return *this;
}
bool AttrBuilder::hasAttribute(Attributes::AttrVal A) const {
return Bits & AttributesImpl::getAttrMask(A);
}
bool AttrBuilder::hasAttributes() const {
return Bits != 0;
}
bool AttrBuilder::hasAttributes(const Attributes &A) const {
return Bits & A.Raw();
}
bool AttrBuilder::hasAlignmentAttr() const {
return Bits & AttributesImpl::getAttrMask(Attributes::Alignment);
}
uint64_t AttrBuilder::getAlignment() const {
if (!hasAlignmentAttr())
return 0;
return 1ULL <<
(((Bits & AttributesImpl::getAttrMask(Attributes::Alignment)) >> 16) - 1);
}
uint64_t AttrBuilder::getStackAlignment() const {
if (!hasAlignmentAttr())
return 0;
return 1ULL <<
(((Bits & AttributesImpl::getAttrMask(Attributes::StackAlignment))>>26)-1);
}
//===----------------------------------------------------------------------===//
// AttributeImpl Definition
//===----------------------------------------------------------------------===//
uint64_t AttributesImpl::getAttrMask(uint64_t Val) {
switch (Val) {
case Attributes::None: return 0;
case Attributes::ZExt: return 1 << 0;
case Attributes::SExt: return 1 << 1;
case Attributes::NoReturn: return 1 << 2;
case Attributes::InReg: return 1 << 3;
case Attributes::StructRet: return 1 << 4;
case Attributes::NoUnwind: return 1 << 5;
case Attributes::NoAlias: return 1 << 6;
case Attributes::ByVal: return 1 << 7;
case Attributes::Nest: return 1 << 8;
case Attributes::ReadNone: return 1 << 9;
case Attributes::ReadOnly: return 1 << 10;
case Attributes::NoInline: return 1 << 11;
case Attributes::AlwaysInline: return 1 << 12;
case Attributes::OptimizeForSize: return 1 << 13;
case Attributes::StackProtect: return 1 << 14;
case Attributes::StackProtectReq: return 1 << 15;
case Attributes::Alignment: return 31 << 16;
case Attributes::NoCapture: return 1 << 21;
case Attributes::NoRedZone: return 1 << 22;
case Attributes::NoImplicitFloat: return 1 << 23;
case Attributes::Naked: return 1 << 24;
case Attributes::InlineHint: return 1 << 25;
case Attributes::StackAlignment: return 7 << 26;
case Attributes::ReturnsTwice: return 1 << 29;
case Attributes::UWTable: return 1 << 30;
case Attributes::NonLazyBind: return 1U << 31;
case Attributes::AddressSafety: return 1ULL << 32;
case Attributes::MinSize: return 1ULL << 33;
}
llvm_unreachable("Unsupported attribute type");
}
bool AttributesImpl::hasAttribute(uint64_t A) const {
return (Bits & getAttrMask(A)) != 0;
}
bool AttributesImpl::hasAttributes() const {
return Bits != 0;
}
bool AttributesImpl::hasAttributes(const Attributes &A) const {
return Bits & A.Raw(); // FIXME: Raw() won't work here in the future.
}
uint64_t AttributesImpl::getAlignment() const {
return Bits & getAttrMask(Attributes::Alignment);
}
uint64_t AttributesImpl::getStackAlignment() const {
return Bits & getAttrMask(Attributes::StackAlignment);
}
//===----------------------------------------------------------------------===//
// AttributeListImpl Definition
//===----------------------------------------------------------------------===//
AttributeSet AttributeSet::get(LLVMContext &C,
ArrayRef<AttributeWithIndex> Attrs) {
// If there are no attributes then return a null AttributesList pointer.
if (Attrs.empty())
return AttributeSet();
#ifndef NDEBUG
for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
assert(Attrs[i].Attrs.hasAttributes() &&
"Pointless attribute!");
assert((!i || Attrs[i-1].Index < Attrs[i].Index) &&
"Misordered AttributesList!");
}
#endif
// Otherwise, build a key to look up the existing attributes.
LLVMContextImpl *pImpl = C.pImpl;
FoldingSetNodeID ID;
AttributeListImpl::Profile(ID, Attrs);
void *InsertPoint;
AttributeListImpl *PA = pImpl->AttrsLists.FindNodeOrInsertPos(ID,
InsertPoint);
// If we didn't find any existing attributes of the same shape then
// create a new one and insert it.
if (!PA) {
PA = new AttributeListImpl(Attrs);
pImpl->AttrsLists.InsertNode(PA, InsertPoint);
}
// Return the AttributesList that we found or created.
return AttributeSet(PA);
}
//===----------------------------------------------------------------------===//
// AttributeSet Method Implementations
//===----------------------------------------------------------------------===//
const AttributeSet &AttributeSet::operator=(const AttributeSet &RHS) {
if (AttrList == RHS.AttrList) return *this;
AttrList = RHS.AttrList;
return *this;
}
/// getNumSlots - Return the number of slots used in this attribute list.
/// This is the number of arguments that have an attribute set on them
/// (including the function itself).
unsigned AttributeSet::getNumSlots() const {
return AttrList ? AttrList->Attrs.size() : 0;
}
/// getSlot - Return the AttributeWithIndex at the specified slot. This
/// holds a number plus a set of attributes.
const AttributeWithIndex &AttributeSet::getSlot(unsigned Slot) const {
assert(AttrList && Slot < AttrList->Attrs.size() && "Slot # out of range!");
return AttrList->Attrs[Slot];
}
/// getAttributes - The attributes for the specified index are returned.
/// Attributes for the result are denoted with Idx = 0. Function notes are
/// denoted with idx = ~0.
Attributes AttributeSet::getAttributes(unsigned Idx) const {
if (AttrList == 0) return Attributes();
const SmallVector<AttributeWithIndex, 4> &Attrs = AttrList->Attrs;
for (unsigned i = 0, e = Attrs.size(); i != e && Attrs[i].Index <= Idx; ++i)
if (Attrs[i].Index == Idx)
return Attrs[i].Attrs;
return Attributes();
}
/// hasAttrSomewhere - Return true if the specified attribute is set for at
/// least one parameter or for the return value.
bool AttributeSet::hasAttrSomewhere(Attributes::AttrVal Attr) const {
if (AttrList == 0) return false;
const SmallVector<AttributeWithIndex, 4> &Attrs = AttrList->Attrs;
for (unsigned i = 0, e = Attrs.size(); i != e; ++i)
if (Attrs[i].Attrs.hasAttribute(Attr))
return true;
return false;
}
unsigned AttributeSet::getNumAttrs() const {
return AttrList ? AttrList->Attrs.size() : 0;
}
Attributes &AttributeSet::getAttributesAtIndex(unsigned i) const {
assert(AttrList && "Trying to get an attribute from an empty list!");
assert(i < AttrList->Attrs.size() && "Index out of range!");
return AttrList->Attrs[i].Attrs;
}
AttributeSet AttributeSet::addAttr(LLVMContext &C, unsigned Idx,
Attributes Attrs) const {
Attributes OldAttrs = getAttributes(Idx);
#ifndef NDEBUG
// FIXME it is not obvious how this should work for alignment.
// For now, say we can't change a known alignment.
unsigned OldAlign = OldAttrs.getAlignment();
unsigned NewAlign = Attrs.getAlignment();
assert((!OldAlign || !NewAlign || OldAlign == NewAlign) &&
"Attempt to change alignment!");
#endif
AttrBuilder NewAttrs =
AttrBuilder(OldAttrs).addAttributes(Attrs);
if (NewAttrs == AttrBuilder(OldAttrs))
return *this;
SmallVector<AttributeWithIndex, 8> NewAttrList;
if (AttrList == 0)
NewAttrList.push_back(AttributeWithIndex::get(Idx, Attrs));
else {
const SmallVector<AttributeWithIndex, 4> &OldAttrList = AttrList->Attrs;
unsigned i = 0, e = OldAttrList.size();
// Copy attributes for arguments before this one.
for (; i != e && OldAttrList[i].Index < Idx; ++i)
NewAttrList.push_back(OldAttrList[i]);
// If there are attributes already at this index, merge them in.
if (i != e && OldAttrList[i].Index == Idx) {
Attrs =
Attributes::get(C, AttrBuilder(Attrs).
addAttributes(OldAttrList[i].Attrs));
++i;
}
NewAttrList.push_back(AttributeWithIndex::get(Idx, Attrs));
// Copy attributes for arguments after this one.
NewAttrList.insert(NewAttrList.end(),
OldAttrList.begin()+i, OldAttrList.end());
}
return get(C, NewAttrList);
}
AttributeSet AttributeSet::removeAttr(LLVMContext &C, unsigned Idx,
Attributes Attrs) const {
#ifndef NDEBUG
// FIXME it is not obvious how this should work for alignment.
// For now, say we can't pass in alignment, which no current use does.
assert(!Attrs.hasAttribute(Attributes::Alignment) &&
"Attempt to exclude alignment!");
#endif
if (AttrList == 0) return AttributeSet();
Attributes OldAttrs = getAttributes(Idx);
AttrBuilder NewAttrs =
AttrBuilder(OldAttrs).removeAttributes(Attrs);
if (NewAttrs == AttrBuilder(OldAttrs))
return *this;
SmallVector<AttributeWithIndex, 8> NewAttrList;
const SmallVector<AttributeWithIndex, 4> &OldAttrList = AttrList->Attrs;
unsigned i = 0, e = OldAttrList.size();
// Copy attributes for arguments before this one.
for (; i != e && OldAttrList[i].Index < Idx; ++i)
NewAttrList.push_back(OldAttrList[i]);
// If there are attributes already at this index, merge them in.
assert(OldAttrList[i].Index == Idx && "Attribute isn't set?");
Attrs = Attributes::get(C, AttrBuilder(OldAttrList[i].Attrs).
removeAttributes(Attrs));
++i;
if (Attrs.hasAttributes()) // If any attributes left for this param, add them.
NewAttrList.push_back(AttributeWithIndex::get(Idx, Attrs));
// Copy attributes for arguments after this one.
NewAttrList.insert(NewAttrList.end(),
OldAttrList.begin()+i, OldAttrList.end());
return get(C, NewAttrList);
}
void AttributeSet::dump() const {
dbgs() << "PAL[ ";
for (unsigned i = 0; i < getNumSlots(); ++i) {
const AttributeWithIndex &PAWI = getSlot(i);
dbgs() << "{" << PAWI.Index << "," << PAWI.Attrs.getAsString() << "} ";
}
dbgs() << "]\n";
}