1 //===- DynamicSize.cpp - Dynamic size 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 size information.
10 //
11 //===----------------------------------------------------------------------===//
12
13 #include "clang/StaticAnalyzer/Core/PathSensitive/DynamicSize.h"
14 #include "clang/AST/Expr.h"
15 #include "clang/Basic/LLVM.h"
16 #include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h"
17 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
18 #include "clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h"
19 #include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h"
20 #include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h"
21
22 namespace clang {
23 namespace ento {
24
getDynamicSize(ProgramStateRef State,const MemRegion * MR,SValBuilder & SVB)25 DefinedOrUnknownSVal getDynamicSize(ProgramStateRef State, const MemRegion *MR,
26 SValBuilder &SVB) {
27 return MR->getMemRegionManager().getStaticSize(MR, SVB);
28 }
29
getDynamicElementCount(ProgramStateRef State,const MemRegion * MR,SValBuilder & SVB,QualType ElementTy)30 DefinedOrUnknownSVal getDynamicElementCount(ProgramStateRef State,
31 const MemRegion *MR,
32 SValBuilder &SVB,
33 QualType ElementTy) {
34 MemRegionManager &MemMgr = MR->getMemRegionManager();
35 ASTContext &Ctx = MemMgr.getContext();
36
37 DefinedOrUnknownSVal Size = getDynamicSize(State, MR, SVB);
38 SVal ElementSizeV = SVB.makeIntVal(
39 Ctx.getTypeSizeInChars(ElementTy).getQuantity(), SVB.getArrayIndexType());
40
41 SVal DivisionV =
42 SVB.evalBinOp(State, BO_Div, Size, ElementSizeV, SVB.getArrayIndexType());
43
44 return DivisionV.castAs<DefinedOrUnknownSVal>();
45 }
46
getDynamicSizeWithOffset(ProgramStateRef State,const SVal & BufV)47 SVal getDynamicSizeWithOffset(ProgramStateRef State, const SVal &BufV) {
48 SValBuilder &SvalBuilder = State->getStateManager().getSValBuilder();
49 const MemRegion *MRegion = BufV.getAsRegion();
50 if (!MRegion)
51 return UnknownVal();
52 RegionOffset Offset = MRegion->getAsOffset();
53 if (Offset.hasSymbolicOffset())
54 return UnknownVal();
55 const MemRegion *BaseRegion = MRegion->getBaseRegion();
56 if (!BaseRegion)
57 return UnknownVal();
58
59 NonLoc OffsetInBytes = SvalBuilder.makeArrayIndex(
60 Offset.getOffset() /
61 MRegion->getMemRegionManager().getContext().getCharWidth());
62 DefinedOrUnknownSVal ExtentInBytes =
63 getDynamicSize(State, BaseRegion, SvalBuilder);
64
65 return SvalBuilder.evalBinOp(State, BinaryOperator::Opcode::BO_Sub,
66 ExtentInBytes, OffsetInBytes,
67 SvalBuilder.getArrayIndexType());
68 }
69
70 } // namespace ento
71 } // namespace clang
72