xref: /freebsd/contrib/llvm-project/clang/lib/AST/Interp/InterpState.cpp (revision a7dea1671b87c07d2d266f836bfa8b58efc7c134)
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 
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 
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 
43 Frame *InterpState::getCurrentFrame() {
44   if (Current && Current->Caller) {
45     return Current;
46   } else {
47     return Parent.getCurrentFrame();
48   }
49 }
50 
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 
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