llvm-project/clang/lib/AST/ByteCode/InterpBlock.cpp
Timm Baeder 25c137e43b
[clang][bytecode] Save a per-block dynamic allocation ID (#154094)
This fixes an old todo item about wrong allocation counting and some
diagnostic differences.
2025-08-19 06:52:21 +02:00

134 lines
3.0 KiB
C++

//===--- Block.cpp - Allocated blocks for the interpreter -------*- 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
//
//===----------------------------------------------------------------------===//
//
// Defines the classes describing allocated blocks.
//
//===----------------------------------------------------------------------===//
#include "InterpBlock.h"
#include "Pointer.h"
using namespace clang;
using namespace clang::interp;
void Block::addPointer(Pointer *P) {
assert(P);
#ifndef NDEBUG
assert(!hasPointer(P));
#endif
if (Pointers)
Pointers->PointeeStorage.BS.Prev = P;
P->PointeeStorage.BS.Next = Pointers;
P->PointeeStorage.BS.Prev = nullptr;
Pointers = P;
#ifndef NDEBUG
assert(hasPointer(P));
#endif
}
void Block::removePointer(Pointer *P) {
assert(P->isBlockPointer());
assert(P);
#ifndef NDEBUG
assert(hasPointer(P));
#endif
BlockPointer &BP = P->PointeeStorage.BS;
if (Pointers == P)
Pointers = BP.Next;
if (BP.Prev)
BP.Prev->PointeeStorage.BS.Next = BP.Next;
if (BP.Next)
BP.Next->PointeeStorage.BS.Prev = BP.Prev;
P->PointeeStorage.BS.Pointee = nullptr;
#ifndef NDEBUG
assert(!hasPointer(P));
#endif
}
void Block::cleanup() {
if (Pointers == nullptr && !isDynamic() && isDead())
(reinterpret_cast<DeadBlock *>(this + 1) - 1)->free();
}
void Block::replacePointer(Pointer *Old, Pointer *New) {
assert(Old);
assert(Old->isBlockPointer());
assert(New);
assert(New->isBlockPointer());
assert(Old != New);
#ifndef NDEBUG
assert(hasPointer(Old));
#endif
BlockPointer &OldBP = Old->PointeeStorage.BS;
BlockPointer &NewBP = New->PointeeStorage.BS;
if (OldBP.Prev)
OldBP.Prev->PointeeStorage.BS.Next = New;
if (OldBP.Next)
OldBP.Next->PointeeStorage.BS.Prev = New;
NewBP.Prev = OldBP.Prev;
NewBP.Next = OldBP.Next;
if (Pointers == Old)
Pointers = New;
OldBP.Pointee = nullptr;
NewBP.Pointee = this;
#ifndef NDEBUG
assert(!hasPointer(Old));
assert(hasPointer(New));
#endif
}
#ifndef NDEBUG
bool Block::hasPointer(const Pointer *P) const {
for (const Pointer *C = Pointers; C; C = C->asBlockPointer().Next) {
if (C == P)
return true;
}
return false;
}
#endif
DeadBlock::DeadBlock(DeadBlock *&Root, Block *Blk)
: Root(Root), B(~0u, Blk->Desc, Blk->isExtern(), Blk->IsStatic,
Blk->isWeak(), Blk->isDummy(), /*IsDead=*/true) {
// Add the block to the chain of dead blocks.
if (Root)
Root->Prev = this;
Next = Root;
Prev = nullptr;
Root = this;
B.DynAllocId = Blk->DynAllocId;
// Transfer pointers.
B.Pointers = Blk->Pointers;
for (Pointer *P = Blk->Pointers; P; P = P->asBlockPointer().Next)
P->PointeeStorage.BS.Pointee = &B;
Blk->Pointers = nullptr;
}
void DeadBlock::free() {
assert(!B.isInitialized());
if (Prev)
Prev->Next = Next;
if (Next)
Next->Prev = Prev;
if (Root == this)
Root = Next;
std::free(this);
}