120 lines · cpp
1//===--- InterpStack.cpp - Stack implementation for the VM ------*- 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-exception6//7//===----------------------------------------------------------------------===//8 9#include "InterpStack.h"10#include "Boolean.h"11#include "FixedPoint.h"12#include "Floating.h"13#include "Integral.h"14#include "MemberPointer.h"15#include "Pointer.h"16#include <cassert>17#include <cstdlib>18 19using namespace clang;20using namespace clang::interp;21 22InterpStack::~InterpStack() {23 if (Chunk && Chunk->Next)24 std::free(Chunk->Next);25 if (Chunk)26 std::free(Chunk);27}28 29// We keep the last chunk around to reuse.30void InterpStack::clear() {31 for (PrimType Item : llvm::reverse(ItemTypes)) {32 TYPE_SWITCH(Item, { this->discard<T>(); });33 }34 assert(ItemTypes.empty());35 assert(empty());36}37 38void InterpStack::clearTo(size_t NewSize) {39 if (NewSize == 0)40 return clear();41 if (NewSize == size())42 return;43 44 assert(NewSize <= size());45 for (PrimType Item : llvm::reverse(ItemTypes)) {46 TYPE_SWITCH(Item, { this->discard<T>(); });47 48 if (size() == NewSize)49 break;50 }51 52 // Note: discard() above already removed the types from ItemTypes.53 assert(size() == NewSize);54}55 56void *InterpStack::peekData(size_t Size) const {57 assert(Chunk && "Stack is empty!");58 59 if (LLVM_LIKELY(Size <= Chunk->size()))60 return reinterpret_cast<void *>(Chunk->start() + Chunk->Size - Size);61 62 StackChunk *Ptr = Chunk;63 while (Size > Ptr->size()) {64 Size -= Ptr->size();65 Ptr = Ptr->Prev;66 assert(Ptr && "Offset too large");67 }68 69 return reinterpret_cast<void *>(Ptr->start() + Ptr->Size - Size);70}71 72void InterpStack::shrink(size_t Size) {73 assert(Chunk && "Chunk is empty!");74 75 // Likely case is that we simply remove something from the current chunk.76 if (LLVM_LIKELY(Size <= Chunk->size())) {77 Chunk->Size -= Size;78 StackSize -= Size;79 return;80 }81 82 while (Size > Chunk->size()) {83 Size -= Chunk->size();84 if (Chunk->Next) {85 std::free(Chunk->Next);86 Chunk->Next = nullptr;87 }88 Chunk->Size = 0;89 Chunk = Chunk->Prev;90 assert(Chunk && "Offset too large");91 }92 93 Chunk->Size -= Size;94 StackSize -= Size;95}96 97void InterpStack::dump() const {98 llvm::errs() << "Items: " << ItemTypes.size() << ". Size: " << size() << '\n';99 if (ItemTypes.empty())100 return;101 102 size_t Index = 0;103 size_t Offset = 0;104 105 // The type of the item on the top of the stack is inserted to the back106 // of the vector, so the iteration has to happen backwards.107 for (PrimType Item : llvm::reverse(ItemTypes)) {108 Offset += align(primSize(Item));109 110 llvm::errs() << Index << '/' << Offset << ": ";111 TYPE_SWITCH(Item, {112 const T &V = peek<T>(Offset);113 llvm::errs() << V;114 });115 llvm::errs() << '\n';116 117 ++Index;118 }119}120