1 //===--- Block.cpp - Allocated blocks for the interpreter -------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // Defines the classes describing allocated blocks. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "InterpBlock.h" 14 #include "Pointer.h" 15 16 using namespace clang; 17 using namespace clang::interp; 18 19 20 21 void Block::addPointer(Pointer *P) { 22 if (IsStatic) 23 return; 24 if (Pointers) 25 Pointers->Prev = P; 26 P->Next = Pointers; 27 P->Prev = nullptr; 28 Pointers = P; 29 } 30 31 void Block::removePointer(Pointer *P) { 32 if (IsStatic) 33 return; 34 if (Pointers == P) 35 Pointers = P->Next; 36 if (P->Prev) 37 P->Prev->Next = P->Next; 38 if (P->Next) 39 P->Next->Prev = P->Prev; 40 } 41 42 void Block::cleanup() { 43 if (Pointers == nullptr && IsDead) 44 (reinterpret_cast<DeadBlock *>(this + 1) - 1)->free(); 45 } 46 47 void Block::movePointer(Pointer *From, Pointer *To) { 48 if (IsStatic) 49 return; 50 To->Prev = From->Prev; 51 if (To->Prev) 52 To->Prev->Next = To; 53 To->Next = From->Next; 54 if (To->Next) 55 To->Next->Prev = To; 56 if (Pointers == From) 57 Pointers = To; 58 59 From->Prev = nullptr; 60 From->Next = nullptr; 61 } 62 63 DeadBlock::DeadBlock(DeadBlock *&Root, Block *Blk) 64 : Root(Root), B(Blk->Desc, Blk->IsStatic, Blk->IsExtern, /*isDead=*/true) { 65 // Add the block to the chain of dead blocks. 66 if (Root) 67 Root->Prev = this; 68 69 Next = Root; 70 Prev = nullptr; 71 Root = this; 72 73 // Transfer pointers. 74 B.Pointers = Blk->Pointers; 75 for (Pointer *P = Blk->Pointers; P; P = P->Next) 76 P->Pointee = &B; 77 } 78 79 void DeadBlock::free() { 80 if (Prev) 81 Prev->Next = Next; 82 if (Next) 83 Next->Prev = Prev; 84 if (Root == this) 85 Root = Next; 86 ::free(this); 87 } 88