//===--- InterpState.cpp - Interpreter for the constexpr VM -----*- 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

//

//===----------------------------------------------------------------------===//

#include "InterpState.h"

#include <limits>

#include "Function.h"

#include "InterpFrame.h"

#include "InterpStack.h"

#include "Opcode.h"

#include "PrimType.h"

#include "Program.h"

#include "State.h"

using namespace clang;

using namespace clang::interp;

using APSInt = llvm::APSInt;

InterpState::InterpState(State &Parent, Program &P, InterpStack &Stk,

                         Context &Ctx, SourceMapper *M)

    : Parent(Parent), M(M), P(P), Stk(Stk), Ctx(Ctx), Current(nullptr),

      CallStackDepth(Parent.getCallStackDepth() + 1) {}

InterpState::~InterpState() {

  while (Current) {

    InterpFrame *Next = Current->Caller;

    delete Current;

    Current = Next;

  }

  while (DeadBlocks) {

    DeadBlock *Next = DeadBlocks->Next;

    free(DeadBlocks);

    DeadBlocks = Next;

  }

}

Frame *InterpState::getCurrentFrame() {

  if (Current && Current->Caller) {

    return Current;

  } else {

    return Parent.getCurrentFrame();

  }

}

bool InterpState::reportOverflow(const Expr *E, const llvm::APSInt &Value) {

  QualType Type = E->getType();

  CCEDiag(E, diag::note_constexpr_overflow) << Value << Type;

  return noteUndefinedBehavior();

}

void InterpState::deallocate(Block *B) {

  Descriptor *Desc = B->getDescriptor();

  if (B->hasPointers()) {

    size_t Size = B->getSize();

    // Allocate a new block, transferring over pointers.

    char *Memory = reinterpret_cast<char *>(malloc(sizeof(DeadBlock) + Size));

    auto *D = new (Memory) DeadBlock(DeadBlocks, B);

    // Move data from one block to another.

    if (Desc->MoveFn)

      Desc->MoveFn(B, B->data(), D->data(), Desc);

  } else {

    // Free storage, if necessary.

    if (Desc->DtorFn)

      Desc->DtorFn(B, B->data(), Desc);

  }

}