clang 17.0.0git
DynamicExtent.cpp
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1//===- DynamicExtent.cpp - Dynamic extent related APIs ----------*- 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// This file defines APIs that track and query dynamic extent information.
10//
11//===----------------------------------------------------------------------===//
12
14#include "clang/AST/Expr.h"
15#include "clang/Basic/LLVM.h"
21
24
25namespace clang {
26namespace ento {
27
28DefinedOrUnknownSVal getDynamicExtent(ProgramStateRef State,
29 const MemRegion *MR, SValBuilder &SVB) {
30 MR = MR->StripCasts();
31
32 if (const DefinedOrUnknownSVal *Size = State->get<DynamicExtentMap>(MR))
33 return *Size;
34
35 return MR->getMemRegionManager().getStaticSize(MR, SVB);
36}
37
38DefinedOrUnknownSVal getElementExtent(QualType Ty, SValBuilder &SVB) {
39 return SVB.makeIntVal(SVB.getContext().getTypeSizeInChars(Ty).getQuantity(),
40 SVB.getArrayIndexType());
41}
42
43DefinedOrUnknownSVal getDynamicElementCount(ProgramStateRef State,
44 const MemRegion *MR,
45 SValBuilder &SVB,
46 QualType ElementTy) {
47 assert(MR != nullptr && "Not-null region expected");
48 MR = MR->StripCasts();
49
50 DefinedOrUnknownSVal Size = getDynamicExtent(State, MR, SVB);
51 SVal ElementSize = getElementExtent(ElementTy, SVB);
52
53 SVal ElementCount =
54 SVB.evalBinOp(State, BO_Div, Size, ElementSize, SVB.getArrayIndexType());
55
56 return ElementCount.castAs<DefinedOrUnknownSVal>();
57}
58
59SVal getDynamicExtentWithOffset(ProgramStateRef State, SVal BufV) {
60 SValBuilder &SvalBuilder = State->getStateManager().getSValBuilder();
61 const MemRegion *MRegion = BufV.getAsRegion();
62 if (!MRegion)
63 return UnknownVal();
64 RegionOffset Offset = MRegion->getAsOffset();
65 if (Offset.hasSymbolicOffset())
66 return UnknownVal();
67 const MemRegion *BaseRegion = MRegion->getBaseRegion();
68 if (!BaseRegion)
69 return UnknownVal();
70
71 NonLoc OffsetInBytes = SvalBuilder.makeArrayIndex(
72 Offset.getOffset() /
73 MRegion->getMemRegionManager().getContext().getCharWidth());
74 DefinedOrUnknownSVal ExtentInBytes =
75 getDynamicExtent(State, BaseRegion, SvalBuilder);
76
77 return SvalBuilder.evalBinOp(State, BinaryOperator::Opcode::BO_Sub,
78 ExtentInBytes, OffsetInBytes,
79 SvalBuilder.getArrayIndexType());
80}
81
82ProgramStateRef setDynamicExtent(ProgramStateRef State, const MemRegion *MR,
83 DefinedOrUnknownSVal Size, SValBuilder &SVB) {
84 MR = MR->StripCasts();
85
86 if (Size.isUnknown())
87 return State;
88
89 return State->set<DynamicExtentMap>(MR->StripCasts(), Size);
90}
91
92} // namespace ento
93} // namespace clang
unsigned Offset
Definition: Format.cpp:2778
Forward-declares and imports various common LLVM datatypes that clang wants to use unqualified.
#define REGISTER_MAP_WITH_PROGRAMSTATE(Name, Key, Value)
Declares an immutable map of type NameTy, suitable for placement into the ProgramState.
MemRegion - The root abstract class for all memory regions.
Definition: MemRegion.h:95
DefinedOrUnknownSVal getDynamicElementCount(ProgramStateRef State, const MemRegion *MR, SValBuilder &SVB, QualType Ty)
IntrusiveRefCntPtr< const ProgramState > ProgramStateRef
SVal getDynamicExtentWithOffset(ProgramStateRef State, SVal BufV)
Get the dynamic extent for a symbolic value that represents a buffer.
DefinedOrUnknownSVal getDynamicExtent(ProgramStateRef State, const MemRegion *MR, SValBuilder &SVB)
DefinedOrUnknownSVal getElementExtent(QualType Ty, SValBuilder &SVB)
ProgramStateRef setDynamicExtent(ProgramStateRef State, const MemRegion *MR, DefinedOrUnknownSVal Extent, SValBuilder &SVB)
Set the dynamic extent Extent of the region MR.