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
19 using namespace clang;
20 using namespace clang::interp;
21
22 using APSInt = llvm::APSInt;
23
InterpState(State & Parent,Program & P,InterpStack & Stk,Context & Ctx,SourceMapper * M)24 InterpState::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
~InterpState()29 InterpState::~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
getCurrentFrame()43 Frame *InterpState::getCurrentFrame() {
44 if (Current && Current->Caller) {
45 return Current;
46 } else {
47 return Parent.getCurrentFrame();
48 }
49 }
50
reportOverflow(const Expr * E,const llvm::APSInt & Value)51 bool 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
deallocate(Block * B)57 void 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