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| //===--- Pointer.cpp - Types for the constexpr VM ---------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "Pointer.h"
#include "Block.h"
#include "Function.h"
#include "PrimType.h"
using namespace clang;
using namespace clang::interp;
Pointer::Pointer(Block *Pointee) : Pointer(Pointee, 0, 0) {}
Pointer::Pointer(const Pointer &P) : Pointer(P.Pointee, P.Base, P.Offset) {}
Pointer::Pointer(Pointer &&P)
: Pointee(P.Pointee), Base(P.Base), Offset(P.Offset) {
if (Pointee)
Pointee->movePointer(&P, this);
}
Pointer::Pointer(Block *Pointee, unsigned Base, unsigned Offset)
: Pointee(Pointee), Base(Base), Offset(Offset) {
assert((Base == RootPtrMark || Base % alignof(void *) == 0) && "wrong base");
if (Pointee)
Pointee->addPointer(this);
}
Pointer::~Pointer() {
if (Pointee) {
Pointee->removePointer(this);
Pointee->cleanup();
}
}
void Pointer::operator=(const Pointer &P) {
Block *Old = Pointee;
if (Pointee)
Pointee->removePointer(this);
Offset = P.Offset;
Base = P.Base;
Pointee = P.Pointee;
if (Pointee)
Pointee->addPointer(this);
if (Old)
Old->cleanup();
}
void Pointer::operator=(Pointer &&P) {
Block *Old = Pointee;
if (Pointee)
Pointee->removePointer(this);
Offset = P.Offset;
Base = P.Base;
Pointee = P.Pointee;
if (Pointee)
Pointee->movePointer(&P, this);
if (Old)
Old->cleanup();
}
APValue Pointer::toAPValue() const {
APValue::LValueBase Base;
llvm::SmallVector<APValue::LValuePathEntry, 5> Path;
CharUnits Offset;
bool IsNullPtr;
bool IsOnePastEnd;
if (isZero()) {
Base = static_cast<const Expr *>(nullptr);
IsNullPtr = true;
IsOnePastEnd = false;
Offset = CharUnits::Zero();
} else {
// Build the lvalue base from the block.
Descriptor *Desc = getDeclDesc();
if (auto *VD = Desc->asValueDecl())
Base = VD;
else if (auto *E = Desc->asExpr())
Base = E;
else
llvm_unreachable("Invalid allocation type");
// Not a null pointer.
IsNullPtr = false;
if (isUnknownSizeArray()) {
IsOnePastEnd = false;
Offset = CharUnits::Zero();
} else {
// TODO: compute the offset into the object.
Offset = CharUnits::Zero();
// Build the path into the object.
Pointer Ptr = *this;
while (Ptr.isField()) {
if (Ptr.isArrayElement()) {
Path.push_back(APValue::LValuePathEntry::ArrayIndex(Ptr.getIndex()));
Ptr = Ptr.getArray();
} else {
// TODO: figure out if base is virtual
bool IsVirtual = false;
// Create a path entry for the field.
Descriptor *Desc = Ptr.getFieldDesc();
if (auto *BaseOrMember = Desc->asDecl()) {
Path.push_back(APValue::LValuePathEntry({BaseOrMember, IsVirtual}));
Ptr = Ptr.getBase();
continue;
}
llvm_unreachable("Invalid field type");
}
}
IsOnePastEnd = isOnePastEnd();
}
}
return APValue(Base, Offset, Path, IsOnePastEnd, IsNullPtr);
}
bool Pointer::isInitialized() const {
assert(Pointee && "Cannot check if null pointer was initialized");
Descriptor *Desc = getFieldDesc();
if (Desc->isPrimitiveArray()) {
if (Pointee->IsStatic)
return true;
// Primitive array field are stored in a bitset.
InitMap *Map = getInitMap();
if (!Map)
return false;
if (Map == (InitMap *)-1)
return true;
return Map->isInitialized(getIndex());
} else {
// Field has its bit in an inline descriptor.
return Base == 0 || getInlineDesc()->IsInitialized;
}
}
void Pointer::initialize() const {
assert(Pointee && "Cannot initialize null pointer");
Descriptor *Desc = getFieldDesc();
if (Desc->isPrimitiveArray()) {
if (!Pointee->IsStatic) {
// Primitive array initializer.
InitMap *&Map = getInitMap();
if (Map == (InitMap *)-1)
return;
if (Map == nullptr)
Map = InitMap::allocate(Desc->getNumElems());
if (Map->initialize(getIndex())) {
free(Map);
Map = (InitMap *)-1;
}
}
} else {
// Field has its bit in an inline descriptor.
assert(Base != 0 && "Only composite fields can be initialised");
getInlineDesc()->IsInitialized = true;
}
}
void Pointer::activate() const {
// Field has its bit in an inline descriptor.
assert(Base != 0 && "Only composite fields can be initialised");
getInlineDesc()->IsActive = true;
}
void Pointer::deactivate() const {
// TODO: this only appears in constructors, so nothing to deactivate.
}
bool Pointer::hasSameBase(const Pointer &A, const Pointer &B) {
return A.Pointee == B.Pointee;
}
bool Pointer::hasSameArray(const Pointer &A, const Pointer &B) {
return A.Base == B.Base && A.getFieldDesc()->IsArray;
}
|