llvm-project/clang/lib/AST/Interp/Block.cpp

88 lines
1.9 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 "Block.h"
#include "Pointer.h"
using namespace clang;
using namespace clang::interp;
void Block::addPointer(Pointer *P) {
if (IsStatic)
return;
if (Pointers)
Pointers->Prev = P;
P->Next = Pointers;
P->Prev = nullptr;
Pointers = P;
}
void Block::removePointer(Pointer *P) {
if (IsStatic)
return;
if (Pointers == P)
Pointers = P->Next;
if (P->Prev)
P->Prev->Next = P->Next;
if (P->Next)
P->Next->Prev = P->Prev;
}
void Block::cleanup() {
if (Pointers == nullptr && IsDead)
(reinterpret_cast<DeadBlock *>(this + 1) - 1)->free();
}
void Block::movePointer(Pointer *From, Pointer *To) {
if (IsStatic)
return;
To->Prev = From->Prev;
if (To->Prev)
To->Prev->Next = To;
To->Next = From->Next;
if (To->Next)
To->Next->Prev = To;
if (Pointers == From)
Pointers = To;
From->Prev = nullptr;
From->Next = nullptr;
}
DeadBlock::DeadBlock(DeadBlock *&Root, Block *Blk)
: Root(Root), B(Blk->Desc, Blk->IsStatic, Blk->IsExtern, /*isDead=*/true) {
// Add the block to the chain of dead blocks.
if (Root)
Root->Prev = this;
Next = Root;
Prev = nullptr;
Root = this;
// Transfer pointers.
B.Pointers = Blk->Pointers;
for (Pointer *P = Blk->Pointers; P; P = P->Next)
P->Pointee = &B;
}
void DeadBlock::free() {
if (Prev)
Prev->Next = Next;
if (Next)
Next->Prev = Prev;
if (Root == this)
Root = Next;
::free(this);
}