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 <limits>
11#include "Function.h"
12#include "InterpFrame.h"
13#include "InterpStack.h"
14#include "Opcode.h"
15#include "PrimType.h"
16#include "Program.h"
17#include "State.h"
18
19using namespace clang;
20using namespace clang::interp;
21
22using APSInt = llvm::APSInt;
23
24InterpState::InterpState(State &Parent, Program &P, InterpStack &Stk,
25                         Context &Ctx, SourceMapper *M)
26    : Parent(Parent), M(M), P(P), Stk(Stk), Ctx(Ctx), Current(nullptr),
27      CallStackDepth(Parent.getCallStackDepth() + 1) {}
28
29InterpState::~InterpState() {
30  while (Current) {
31    InterpFrame *Next = Current->Caller;
32    delete Current;
33    Current = Next;
34  }
35
36  while (DeadBlocks) {
37    DeadBlock *Next = DeadBlocks->Next;
38    free(DeadBlocks);
39    DeadBlocks = Next;
40  }
41}
42
43Frame *InterpState::getCurrentFrame() {
44  if (Current && Current->Caller) {
45    return Current;
46  } else {
47    return Parent.getCurrentFrame();
48  }
49}
50
51bool InterpState::reportOverflow(const Expr *E, const llvm::APSInt &Value) {
52  QualType Type = E->getType();
53  CCEDiag(E, diag::note_constexpr_overflow) << Value << Type;
54  return noteUndefinedBehavior();
55}
56
57void InterpState::deallocate(Block *B) {
58  Descriptor *Desc = B->getDescriptor();
59  if (B->hasPointers()) {
60    size_t Size = B->getSize();
61
62    // Allocate a new block, transferring over pointers.
63    char *Memory = reinterpret_cast<char *>(malloc(sizeof(DeadBlock) + Size));
64    auto *D = new (Memory) DeadBlock(DeadBlocks, B);
65
66    // Move data from one block to another.
67    if (Desc->MoveFn)
68      Desc->MoveFn(B, B->data(), D->data(), Desc);
69  } else {
70    // Free storage, if necessary.
71    if (Desc->DtorFn)
72      Desc->DtorFn(B, B->data(), Desc);
73  }
74}
75