1//===--- InterpState.cpp - Interpreter for the constexpr 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-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "InterpState.h"
10#include "InterpFrame.h"
11#include "InterpStack.h"
12#include "Program.h"
13#include "State.h"
14
15using namespace clang;
16using namespace clang::interp;
17
18InterpState::InterpState(State &Parent, Program &P, InterpStack &Stk,
19                         Context &Ctx, SourceMapper *M)
20    : Parent(Parent), M(M), P(P), Stk(Stk), Ctx(Ctx), Current(nullptr) {}
21
22InterpState::~InterpState() {
23  while (Current) {
24    InterpFrame *Next = Current->Caller;
25    delete Current;
26    Current = Next;
27  }
28
29  while (DeadBlocks) {
30    DeadBlock *Next = DeadBlocks->Next;
31    std::free(DeadBlocks);
32    DeadBlocks = Next;
33  }
34}
35
36Frame *InterpState::getCurrentFrame() {
37  if (Current && Current->Caller)
38    return Current;
39  return Parent.getCurrentFrame();
40}
41
42bool InterpState::reportOverflow(const Expr *E, const llvm::APSInt &Value) {
43  QualType Type = E->getType();
44  CCEDiag(E, diag::note_constexpr_overflow) << Value << Type;
45  return noteUndefinedBehavior();
46}
47
48void InterpState::deallocate(Block *B) {
49  assert(B);
50  const Descriptor *Desc = B->getDescriptor();
51  assert(Desc);
52
53  if (B->hasPointers()) {
54    size_t Size = B->getSize();
55
56    // Allocate a new block, transferring over pointers.
57    char *Memory =
58        reinterpret_cast<char *>(std::malloc(sizeof(DeadBlock) + Size));
59    auto *D = new (Memory) DeadBlock(DeadBlocks, B);
60
61    // Move data and metadata from the old block to the new (dead)block.
62    if (Desc->MoveFn) {
63      Desc->MoveFn(B, B->data(), D->data(), Desc);
64      if (Desc->getMetadataSize() > 0)
65        std::memcpy(D->rawData(), B->rawData(), Desc->getMetadataSize());
66    }
67
68    // We moved the contents over to the DeadBlock.
69    B->IsInitialized = false;
70  } else {
71    B->invokeDtor();
72  }
73}
74