clang 17.0.0git
Go to the documentation of this file.
1//===--- InterpState.cpp - Interpreter for the constexpr VM -----*- C++ -*-===//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
9#include "InterpState.h"
10#include "InterpFrame.h"
11#include "InterpStack.h"
12#include "Program.h"
13#include "State.h"
15using namespace clang;
16using namespace clang::interp;
19 Context &Ctx, SourceMapper *M)
20 : Parent(Parent), M(M), P(P), Stk(Stk), Ctx(Ctx), Current(nullptr) {}
23 while (Current) {
24 InterpFrame *Next = Current->Caller;
25 delete Current;
26 Current = Next;
27 }
29 while (DeadBlocks) {
30 DeadBlock *Next = DeadBlocks->Next;
31 free(DeadBlocks);
32 DeadBlocks = Next;
33 }
37 if (Current && Current->Caller)
38 return Current;
39 return Parent.getCurrentFrame();
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();
49 Descriptor *Desc = B->getDescriptor();
50 if (B->hasPointers()) {
51 size_t Size = B->getSize();
53 // Allocate a new block, transferring over pointers.
54 char *Memory = reinterpret_cast<char *>(malloc(sizeof(DeadBlock) + Size));
55 auto *D = new (Memory) DeadBlock(DeadBlocks, B);
57 // Move data from one block to another.
58 if (Desc->MoveFn)
59 Desc->MoveFn(B, B->data(), D->data(), Desc);
60 } else {
61 // Free storage, if necessary.
62 if (Desc->DtorFn)
63 Desc->DtorFn(B, B->data(), Desc);
64 }
NodeId Parent
Definition: ASTDiff.cpp:191
StringRef P
This represents one expression.
Definition: Expr.h:110
QualType getType() const
Definition: Expr.h:142
A (possibly-)qualified type.
Definition: Type.h:736
The base class of the type hierarchy.
Definition: Type.h:1568
A memory block, either on the stack or in the heap.
Definition: InterpBlock.h:49
unsigned getSize() const
Returns the size of the block.
Definition: InterpBlock.h:71
Descriptor * getDescriptor() const
Returns the block's descriptor.
Definition: InterpBlock.h:61
char * data()
Returns a pointer to the stored data.
Definition: InterpBlock.h:77
bool hasPointers() const
Checks if the block has any live pointers.
Definition: InterpBlock.h:63
Holds all information required to evaluate constexpr code in a module.
Definition: Context.h:35
Descriptor for a dead block.
Definition: InterpBlock.h:147
Base class for stack frames, shared between VM and walker.
Definition: Frame.h:25
Frame storing local variables.
Definition: InterpFrame.h:28
InterpFrame * Caller
The frame of the previous function.
Definition: InterpFrame.h:31
Stack frame storing temporaries and parameters.
Definition: InterpStack.h:25
bool reportOverflow(const Expr *E, const llvm::APSInt &Value)
Reports overflow and return true if evaluation should continue.
Definition: InterpState.cpp:42
bool noteUndefinedBehavior() override
Definition: InterpState.h:68
Frame * getCurrentFrame() override
Definition: InterpState.cpp:36
InterpFrame * Current
The current frame.
Definition: InterpState.h:108
InterpState(State &Parent, Program &P, InterpStack &Stk, Context &Ctx, SourceMapper *M=nullptr)
Definition: InterpState.cpp:18
void deallocate(Block *B)
Deallocates a pointer.
Definition: InterpState.cpp:48
The program contains and links the bytecode for all functions.
Definition: Program.h:40
Interface for classes which map locations to sources.
Definition: Source.h:91
Interface for the VM to interact with the AST walker's context.
Definition: State.h:55
virtual Frame * getCurrentFrame()=0
OptionalDiagnostic CCEDiag(SourceLocation Loc, diag::kind DiagId=diag::note_invalid_subexpr_in_const_expr, unsigned ExtraNotes=0)
Diagnose that the evaluation does not produce a C++11 core constant expression.
Definition: State.cpp:42
Describes a memory block created by an allocation site.
Definition: Descriptor.h:76
const BlockMoveFn MoveFn
Definition: Descriptor.h:115
const BlockDtorFn DtorFn
Definition: Descriptor.h:114