llvm-6502/lib/VMCore/Attributes.cpp
Charles Davis 970bfcc7d8 Add a new 'hotpatch' attribute. This attribute will insert a two-byte no-op
instruction at the beginning of each function that has the attribute, allowing
the function to be easily hooked and/or patched.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117264 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-25 15:37:09 +00:00

338 lines
11 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 AttributesList class and Attribute utilities.
//
//===----------------------------------------------------------------------===//
#include "llvm/Attributes.h"
#include "llvm/Type.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/FoldingSet.h"
#include "llvm/System/Atomic.h"
#include "llvm/System/Mutex.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
//===----------------------------------------------------------------------===//
// Attribute Function Definitions
//===----------------------------------------------------------------------===//
std::string Attribute::getAsString(Attributes Attrs) {
std::string Result;
if (Attrs & Attribute::ZExt)
Result += "zeroext ";
if (Attrs & Attribute::SExt)
Result += "signext ";
if (Attrs & Attribute::NoReturn)
Result += "noreturn ";
if (Attrs & Attribute::NoUnwind)
Result += "nounwind ";
if (Attrs & Attribute::InReg)
Result += "inreg ";
if (Attrs & Attribute::NoAlias)
Result += "noalias ";
if (Attrs & Attribute::NoCapture)
Result += "nocapture ";
if (Attrs & Attribute::StructRet)
Result += "sret ";
if (Attrs & Attribute::ByVal)
Result += "byval ";
if (Attrs & Attribute::Nest)
Result += "nest ";
if (Attrs & Attribute::ReadNone)
Result += "readnone ";
if (Attrs & Attribute::ReadOnly)
Result += "readonly ";
if (Attrs & Attribute::OptimizeForSize)
Result += "optsize ";
if (Attrs & Attribute::NoInline)
Result += "noinline ";
if (Attrs & Attribute::InlineHint)
Result += "inlinehint ";
if (Attrs & Attribute::AlwaysInline)
Result += "alwaysinline ";
if (Attrs & Attribute::StackProtect)
Result += "ssp ";
if (Attrs & Attribute::StackProtectReq)
Result += "sspreq ";
if (Attrs & Attribute::NoRedZone)
Result += "noredzone ";
if (Attrs & Attribute::NoImplicitFloat)
Result += "noimplicitfloat ";
if (Attrs & Attribute::Naked)
Result += "naked ";
if (Attrs & Attribute::Hotpatch)
Result += "hotpatch ";
if (Attrs & Attribute::StackAlignment) {
Result += "alignstack(";
Result += utostr(Attribute::getStackAlignmentFromAttrs(Attrs));
Result += ") ";
}
if (Attrs & Attribute::Alignment) {
Result += "align ";
Result += utostr(Attribute::getAlignmentFromAttrs(Attrs));
Result += " ";
}
// Trim the trailing space.
assert(!Result.empty() && "Unknown attribute!");
Result.erase(Result.end()-1);
return Result;
}
Attributes Attribute::typeIncompatible(const Type *Ty) {
Attributes Incompatible = None;
if (!Ty->isIntegerTy())
// Attributes that only apply to integers.
Incompatible |= SExt | ZExt;
if (!Ty->isPointerTy())
// Attributes that only apply to pointers.
Incompatible |= ByVal | Nest | NoAlias | StructRet | NoCapture;
return Incompatible;
}
//===----------------------------------------------------------------------===//
// AttributeListImpl Definition
//===----------------------------------------------------------------------===//
namespace llvm {
class AttributeListImpl : public FoldingSetNode {
sys::cas_flag RefCount;
// AttributesList is uniqued, these should not be publicly available.
void operator=(const AttributeListImpl &); // Do not implement
AttributeListImpl(const AttributeListImpl &); // Do not implement
~AttributeListImpl(); // Private implementation
public:
SmallVector<AttributeWithIndex, 4> Attrs;
AttributeListImpl(const AttributeWithIndex *Attr, unsigned NumAttrs)
: Attrs(Attr, Attr+NumAttrs) {
RefCount = 0;
}
void AddRef() { sys::AtomicIncrement(&RefCount); }
void DropRef() {
sys::cas_flag old = sys::AtomicDecrement(&RefCount);
if (old == 0) delete this;
}
void Profile(FoldingSetNodeID &ID) const {
Profile(ID, Attrs.data(), Attrs.size());
}
static void Profile(FoldingSetNodeID &ID, const AttributeWithIndex *Attr,
unsigned NumAttrs) {
for (unsigned i = 0; i != NumAttrs; ++i)
ID.AddInteger(uint64_t(Attr[i].Attrs) << 32 | unsigned(Attr[i].Index));
}
};
}
static ManagedStatic<sys::SmartMutex<true> > ALMutex;
static ManagedStatic<FoldingSet<AttributeListImpl> > AttributesLists;
AttributeListImpl::~AttributeListImpl() {
sys::SmartScopedLock<true> Lock(*ALMutex);
AttributesLists->RemoveNode(this);
}
AttrListPtr AttrListPtr::get(const AttributeWithIndex *Attrs, unsigned NumAttrs) {
// If there are no attributes then return a null AttributesList pointer.
if (NumAttrs == 0)
return AttrListPtr();
#ifndef NDEBUG
for (unsigned i = 0; i != NumAttrs; ++i) {
assert(Attrs[i].Attrs != Attribute::None &&
"Pointless attribute!");
assert((!i || Attrs[i-1].Index < Attrs[i].Index) &&
"Misordered AttributesList!");
}
#endif
// Otherwise, build a key to look up the existing attributes.
FoldingSetNodeID ID;
AttributeListImpl::Profile(ID, Attrs, NumAttrs);
void *InsertPos;
sys::SmartScopedLock<true> Lock(*ALMutex);
AttributeListImpl *PAL =
AttributesLists->FindNodeOrInsertPos(ID, InsertPos);
// If we didn't find any existing attributes of the same shape then
// create a new one and insert it.
if (!PAL) {
PAL = new AttributeListImpl(Attrs, NumAttrs);
AttributesLists->InsertNode(PAL, InsertPos);
}
// Return the AttributesList that we found or created.
return AttrListPtr(PAL);
}
//===----------------------------------------------------------------------===//
// AttrListPtr Method Implementations
//===----------------------------------------------------------------------===//
AttrListPtr::AttrListPtr(AttributeListImpl *LI) : AttrList(LI) {
if (LI) LI->AddRef();
}
AttrListPtr::AttrListPtr(const AttrListPtr &P) : AttrList(P.AttrList) {
if (AttrList) AttrList->AddRef();
}
const AttrListPtr &AttrListPtr::operator=(const AttrListPtr &RHS) {
sys::SmartScopedLock<true> Lock(*ALMutex);
if (AttrList == RHS.AttrList) return *this;
if (AttrList) AttrList->DropRef();
AttrList = RHS.AttrList;
if (AttrList) AttrList->AddRef();
return *this;
}
AttrListPtr::~AttrListPtr() {
if (AttrList) AttrList->DropRef();
}
/// 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 AttrListPtr::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 &AttrListPtr::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 AttrListPtr::getAttributes(unsigned Idx) const {
if (AttrList == 0) return Attribute::None;
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 Attribute::None;
}
/// hasAttrSomewhere - Return true if the specified attribute is set for at
/// least one parameter or for the return value.
bool AttrListPtr::hasAttrSomewhere(Attributes 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 & Attr)
return true;
return false;
}
AttrListPtr AttrListPtr::addAttr(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.
Attributes OldAlign = OldAttrs & Attribute::Alignment;
Attributes NewAlign = Attrs & Attribute::Alignment;
assert((!OldAlign || !NewAlign || OldAlign == NewAlign) &&
"Attempt to change alignment!");
#endif
Attributes NewAttrs = OldAttrs | Attrs;
if (NewAttrs == 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 |= 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(NewAttrList.data(), NewAttrList.size());
}
AttrListPtr AttrListPtr::removeAttr(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 & Attribute::Alignment) && "Attempt to exclude alignment!");
#endif
if (AttrList == 0) return AttrListPtr();
Attributes OldAttrs = getAttributes(Idx);
Attributes NewAttrs = OldAttrs & ~Attrs;
if (NewAttrs == 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 = OldAttrList[i].Attrs & ~Attrs;
++i;
if (Attrs) // If any attributes left for this parameter, 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(NewAttrList.data(), NewAttrList.size());
}
void AttrListPtr::dump() const {
dbgs() << "PAL[ ";
for (unsigned i = 0; i < getNumSlots(); ++i) {
const AttributeWithIndex &PAWI = getSlot(i);
dbgs() << "{" << PAWI.Index << "," << PAWI.Attrs << "} ";
}
dbgs() << "]\n";
}