Bug Summary

File:clang/lib/AST/Interp/Descriptor.cpp
Warning:line 99, column 7
Called C++ object pointer is null

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name Descriptor.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mthread-model posix -mframe-pointer=none -relaxed-aliasing -fmath-errno -fno-rounding-math -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-10/lib/clang/10.0.0 -D CLANG_VENDOR="Debian " -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/build-llvm/tools/clang/lib/AST -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/AST -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/include -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/build-llvm/include -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-10/lib/clang/10.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/build-llvm/tools/clang/lib/AST -fdebug-prefix-map=/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809=. -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -fobjc-runtime=gcc -fno-common -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -o /tmp/scan-build-2019-12-09-002921-48462-1 -x c++ /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/AST/Interp/Descriptor.cpp
1//===--- Descriptor.cpp - Types 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 "Descriptor.h"
10#include "Pointer.h"
11#include "PrimType.h"
12#include "Record.h"
13
14using namespace clang;
15using namespace clang::interp;
16
17template <typename T>
18static void ctorTy(Block *, char *Ptr, bool, bool, bool, Descriptor *) {
19 new (Ptr) T();
20}
21
22template <typename T> static void dtorTy(Block *, char *Ptr, Descriptor *) {
23 reinterpret_cast<T *>(Ptr)->~T();
24}
25
26template <typename T>
27static void moveTy(Block *, char *Src, char *Dst, Descriptor *) {
28 auto *SrcPtr = reinterpret_cast<T *>(Src);
29 auto *DstPtr = reinterpret_cast<T *>(Dst);
30 new (DstPtr) T(std::move(*SrcPtr));
31}
32
33template <typename T>
34static void ctorArrayTy(Block *, char *Ptr, bool, bool, bool, Descriptor *D) {
35 for (unsigned I = 0, NE = D->getNumElems(); I < NE; ++I) {
36 new (&reinterpret_cast<T *>(Ptr)[I]) T();
37 }
38}
39
40template <typename T>
41static void dtorArrayTy(Block *, char *Ptr, Descriptor *D) {
42 for (unsigned I = 0, NE = D->getNumElems(); I < NE; ++I) {
43 reinterpret_cast<T *>(Ptr)[I].~T();
44 }
45}
46
47template <typename T>
48static void moveArrayTy(Block *, char *Src, char *Dst, Descriptor *D) {
49 for (unsigned I = 0, NE = D->getNumElems(); I < NE; ++I) {
50 auto *SrcPtr = &reinterpret_cast<T *>(Src)[I];
51 auto *DstPtr = &reinterpret_cast<T *>(Dst)[I];
52 new (DstPtr) T(std::move(*SrcPtr));
53 }
54}
55
56static void ctorArrayDesc(Block *B, char *Ptr, bool IsConst, bool IsMutable,
57 bool IsActive, Descriptor *D) {
58 const unsigned NumElems = D->getNumElems();
59 const unsigned ElemSize =
60 D->ElemDesc->getAllocSize() + sizeof(InlineDescriptor);
61
62 unsigned ElemOffset = 0;
63 for (unsigned I = 0; I < NumElems; ++I, ElemOffset += ElemSize) {
64 auto *ElemPtr = Ptr + ElemOffset;
65 auto *Desc = reinterpret_cast<InlineDescriptor *>(ElemPtr);
66 auto *ElemLoc = reinterpret_cast<char *>(Desc + 1);
67 auto *SD = D->ElemDesc;
68
69 Desc->Offset = ElemOffset + sizeof(InlineDescriptor);
70 Desc->Desc = SD;
71 Desc->IsInitialized = true;
72 Desc->IsBase = false;
73 Desc->IsActive = IsActive;
74 Desc->IsConst = IsConst || D->IsConst;
75 Desc->IsMutable = IsMutable || D->IsMutable;
76 if (auto Fn = D->ElemDesc->CtorFn)
77 Fn(B, ElemLoc, Desc->IsConst, Desc->IsMutable, IsActive, D->ElemDesc);
78 }
79}
80
81static void dtorArrayDesc(Block *B, char *Ptr, Descriptor *D) {
82 const unsigned NumElems = D->getNumElems();
83 const unsigned ElemSize =
84 D->ElemDesc->getAllocSize() + sizeof(InlineDescriptor);
85
86 unsigned ElemOffset = 0;
87 for (unsigned I = 0; I < NumElems; ++I, ElemOffset += ElemSize) {
88 auto *ElemPtr = Ptr + ElemOffset;
89 auto *Desc = reinterpret_cast<InlineDescriptor *>(ElemPtr);
90 auto *ElemLoc = reinterpret_cast<char *>(Desc + 1);
91 if (auto Fn = D->ElemDesc->DtorFn)
92 Fn(B, ElemLoc, D->ElemDesc);
93 }
94}
95
96static void moveArrayDesc(Block *B, char *Src, char *Dst, Descriptor *D) {
97 const unsigned NumElems = D->getNumElems();
98 const unsigned ElemSize =
99 D->ElemDesc->getAllocSize() + sizeof(InlineDescriptor);
Called C++ object pointer is null
100
101 unsigned ElemOffset = 0;
102 for (unsigned I = 0; I < NumElems; ++I, ElemOffset += ElemSize) {
103 auto *SrcPtr = Src + ElemOffset;
104 auto *DstPtr = Dst + ElemOffset;
105
106 auto *SrcDesc = reinterpret_cast<InlineDescriptor *>(SrcPtr);
107 auto *SrcElemLoc = reinterpret_cast<char *>(SrcDesc + 1);
108 auto *DstDesc = reinterpret_cast<InlineDescriptor *>(DstPtr);
109 auto *DstElemLoc = reinterpret_cast<char *>(DstDesc + 1);
110
111 *DstDesc = *SrcDesc;
112 if (auto Fn = D->ElemDesc->MoveFn)
113 Fn(B, SrcElemLoc, DstElemLoc, D->ElemDesc);
114 }
115}
116
117static void ctorRecord(Block *B, char *Ptr, bool IsConst, bool IsMutable,
118 bool IsActive, Descriptor *D) {
119 const bool IsUnion = D->ElemRecord->isUnion();
120 auto CtorSub = [=](unsigned SubOff, Descriptor *F, bool IsBase) {
121 auto *Desc = reinterpret_cast<InlineDescriptor *>(Ptr + SubOff) - 1;
122 Desc->Offset = SubOff;
123 Desc->Desc = F;
124 Desc->IsInitialized = (B->isStatic() || F->IsArray) && !IsBase;
125 Desc->IsBase = IsBase;
126 Desc->IsActive = IsActive && !IsUnion;
127 Desc->IsConst = IsConst || F->IsConst;
128 Desc->IsMutable = IsMutable || F->IsMutable;
129 if (auto Fn = F->CtorFn)
130 Fn(B, Ptr + SubOff, Desc->IsConst, Desc->IsMutable, Desc->IsActive, F);
131 };
132 for (const auto &B : D->ElemRecord->bases())
133 CtorSub(B.Offset, B.Desc, /*isBase=*/true);
134 for (const auto &F : D->ElemRecord->fields())
135 CtorSub(F.Offset, F.Desc, /*isBase=*/false);
136 for (const auto &V : D->ElemRecord->virtual_bases())
137 CtorSub(V.Offset, V.Desc, /*isBase=*/true);
138}
139
140static void dtorRecord(Block *B, char *Ptr, Descriptor *D) {
141 auto DtorSub = [=](unsigned SubOff, Descriptor *F) {
142 if (auto Fn = F->DtorFn)
143 Fn(B, Ptr + SubOff, F);
144 };
145 for (const auto &F : D->ElemRecord->bases())
146 DtorSub(F.Offset, F.Desc);
147 for (const auto &F : D->ElemRecord->fields())
148 DtorSub(F.Offset, F.Desc);
149 for (const auto &F : D->ElemRecord->virtual_bases())
150 DtorSub(F.Offset, F.Desc);
151}
152
153static void moveRecord(Block *B, char *Src, char *Dst, Descriptor *D) {
154 for (const auto &F : D->ElemRecord->fields()) {
155 auto FieldOff = F.Offset;
156 auto FieldDesc = F.Desc;
157
158 *(reinterpret_cast<Descriptor **>(Dst + FieldOff) - 1) = FieldDesc;
159 if (auto Fn = FieldDesc->MoveFn)
160 Fn(B, Src + FieldOff, Dst + FieldOff, FieldDesc);
161 }
162}
163
164static BlockCtorFn getCtorPrim(PrimType Type) {
165 COMPOSITE_TYPE_SWITCH(Type, return ctorTy<T>, return nullptr)switch (Type) { case PT_Ptr: { using T = PrimConv<PT_Ptr>
::T; do {return ctorTy<T>;} while(0); break; } default:
do { return nullptr; } while(0); break; }
;
166}
167
168static BlockDtorFn getDtorPrim(PrimType Type) {
169 COMPOSITE_TYPE_SWITCH(Type, return dtorTy<T>, return nullptr)switch (Type) { case PT_Ptr: { using T = PrimConv<PT_Ptr>
::T; do {return dtorTy<T>;} while(0); break; } default:
do { return nullptr; } while(0); break; }
;
170}
171
172static BlockMoveFn getMovePrim(PrimType Type) {
173 COMPOSITE_TYPE_SWITCH(Type, return moveTy<T>, return nullptr)switch (Type) { case PT_Ptr: { using T = PrimConv<PT_Ptr>
::T; do {return moveTy<T>;} while(0); break; } default:
do { return nullptr; } while(0); break; }
;
174}
175
176static BlockCtorFn getCtorArrayPrim(PrimType Type) {
177 COMPOSITE_TYPE_SWITCH(Type, return ctorArrayTy<T>, return nullptr)switch (Type) { case PT_Ptr: { using T = PrimConv<PT_Ptr>
::T; do {return ctorArrayTy<T>;} while(0); break; } default
: do { return nullptr; } while(0); break; }
;
178}
179
180static BlockDtorFn getDtorArrayPrim(PrimType Type) {
181 COMPOSITE_TYPE_SWITCH(Type, return dtorArrayTy<T>, return nullptr)switch (Type) { case PT_Ptr: { using T = PrimConv<PT_Ptr>
::T; do {return dtorArrayTy<T>;} while(0); break; } default
: do { return nullptr; } while(0); break; }
;
182}
183
184static BlockMoveFn getMoveArrayPrim(PrimType Type) {
185 COMPOSITE_TYPE_SWITCH(Type, return moveArrayTy<T>, return nullptr)switch (Type) { case PT_Ptr: { using T = PrimConv<PT_Ptr>
::T; do {return moveArrayTy<T>;} while(0); break; } default
: do { return nullptr; } while(0); break; }
;
186}
187
188Descriptor::Descriptor(const DeclTy &D, PrimType Type, bool IsConst,
189 bool IsTemporary, bool IsMutable)
190 : Source(D), ElemSize(primSize(Type)), Size(ElemSize), AllocSize(Size),
191 IsConst(IsConst), IsMutable(IsMutable), IsTemporary(IsTemporary),
192 CtorFn(getCtorPrim(Type)), DtorFn(getDtorPrim(Type)),
193 MoveFn(getMovePrim(Type)) {
194 assert(Source && "Missing source")((Source && "Missing source") ? static_cast<void>
(0) : __assert_fail ("Source && \"Missing source\"",
"/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/AST/Interp/Descriptor.cpp"
, 194, __PRETTY_FUNCTION__))
;
195}
196
197Descriptor::Descriptor(const DeclTy &D, PrimType Type, size_t NumElems,
198 bool IsConst, bool IsTemporary, bool IsMutable)
199 : Source(D), ElemSize(primSize(Type)), Size(ElemSize * NumElems),
200 AllocSize(align(Size) + sizeof(InitMap *)), IsConst(IsConst),
201 IsMutable(IsMutable), IsTemporary(IsTemporary), IsArray(true),
202 CtorFn(getCtorArrayPrim(Type)), DtorFn(getDtorArrayPrim(Type)),
203 MoveFn(getMoveArrayPrim(Type)) {
204 assert(Source && "Missing source")((Source && "Missing source") ? static_cast<void>
(0) : __assert_fail ("Source && \"Missing source\"",
"/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/AST/Interp/Descriptor.cpp"
, 204, __PRETTY_FUNCTION__))
;
205}
206
207Descriptor::Descriptor(const DeclTy &D, PrimType Type, bool IsTemporary,
208 UnknownSize)
209 : Source(D), ElemSize(primSize(Type)), Size(UnknownSizeMark),
210 AllocSize(alignof(void *)), IsConst(true), IsMutable(false),
211 IsTemporary(IsTemporary), IsArray(true), CtorFn(getCtorArrayPrim(Type)),
212 DtorFn(getDtorArrayPrim(Type)), MoveFn(getMoveArrayPrim(Type)) {
213 assert(Source && "Missing source")((Source && "Missing source") ? static_cast<void>
(0) : __assert_fail ("Source && \"Missing source\"",
"/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/AST/Interp/Descriptor.cpp"
, 213, __PRETTY_FUNCTION__))
;
214}
215
216Descriptor::Descriptor(const DeclTy &D, Descriptor *Elem, unsigned NumElems,
217 bool IsConst, bool IsTemporary, bool IsMutable)
218 : Source(D), ElemSize(Elem->getAllocSize() + sizeof(InlineDescriptor)),
219 Size(ElemSize * NumElems),
220 AllocSize(std::max<size_t>(alignof(void *), Size)), ElemDesc(Elem),
221 IsConst(IsConst), IsMutable(IsMutable), IsTemporary(IsTemporary),
222 IsArray(true), CtorFn(ctorArrayDesc), DtorFn(dtorArrayDesc),
223 MoveFn(moveArrayDesc) {
224 assert(Source && "Missing source")((Source && "Missing source") ? static_cast<void>
(0) : __assert_fail ("Source && \"Missing source\"",
"/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/AST/Interp/Descriptor.cpp"
, 224, __PRETTY_FUNCTION__))
;
225}
226
227Descriptor::Descriptor(const DeclTy &D, Descriptor *Elem, bool IsTemporary,
228 UnknownSize)
229 : Source(D), ElemSize(Elem->getAllocSize() + sizeof(InlineDescriptor)),
230 Size(UnknownSizeMark), AllocSize(alignof(void *)), ElemDesc(Elem),
231 IsConst(true), IsMutable(false), IsTemporary(IsTemporary), IsArray(true),
232 CtorFn(ctorArrayDesc), DtorFn(dtorArrayDesc), MoveFn(moveArrayDesc) {
233 assert(Source && "Missing source")((Source && "Missing source") ? static_cast<void>
(0) : __assert_fail ("Source && \"Missing source\"",
"/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/AST/Interp/Descriptor.cpp"
, 233, __PRETTY_FUNCTION__))
;
234}
235
236Descriptor::Descriptor(const DeclTy &D, Record *R, bool IsConst,
237 bool IsTemporary, bool IsMutable)
238 : Source(D), ElemSize(std::max<size_t>(alignof(void *), R->getFullSize())),
239 Size(ElemSize), AllocSize(Size), ElemRecord(R), IsConst(IsConst),
240 IsMutable(IsMutable), IsTemporary(IsTemporary), CtorFn(ctorRecord),
241 DtorFn(dtorRecord), MoveFn(moveRecord) {
242 assert(Source && "Missing source")((Source && "Missing source") ? static_cast<void>
(0) : __assert_fail ("Source && \"Missing source\"",
"/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/AST/Interp/Descriptor.cpp"
, 242, __PRETTY_FUNCTION__))
;
243}
244
245QualType Descriptor::getType() const {
246 if (auto *E = asExpr())
247 return E->getType();
248 if (auto *D = asValueDecl())
249 return D->getType();
250 llvm_unreachable("Invalid descriptor type")::llvm::llvm_unreachable_internal("Invalid descriptor type", "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/AST/Interp/Descriptor.cpp"
, 250)
;
251}
252
253SourceLocation Descriptor::getLocation() const {
254 if (auto *D = Source.dyn_cast<const Decl *>())
255 return D->getLocation();
256 if (auto *E = Source.dyn_cast<const Expr *>())
257 return E->getExprLoc();
258 llvm_unreachable("Invalid descriptor type")::llvm::llvm_unreachable_internal("Invalid descriptor type", "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/AST/Interp/Descriptor.cpp"
, 258)
;
259}
260
261InitMap::InitMap(unsigned N) : UninitFields(N) {
262 for (unsigned I = 0; I < N / PER_FIELD; ++I) {
263 data()[I] = 0;
264 }
265}
266
267InitMap::T *InitMap::data() {
268 auto *Start = reinterpret_cast<char *>(this) + align(sizeof(InitMap));
269 return reinterpret_cast<T *>(Start);
270}
271
272bool InitMap::initialize(unsigned I) {
273 unsigned Bucket = I / PER_FIELD;
274 unsigned Mask = 1ull << static_cast<uint64_t>(I % PER_FIELD);
275 if (!(data()[Bucket] & Mask)) {
276 data()[Bucket] |= Mask;
277 UninitFields -= 1;
278 }
279 return UninitFields == 0;
280}
281
282bool InitMap::isInitialized(unsigned I) {
283 unsigned Bucket = I / PER_FIELD;
284 unsigned Mask = 1ull << static_cast<uint64_t>(I % PER_FIELD);
285 return data()[Bucket] & Mask;
286}
287
288InitMap *InitMap::allocate(unsigned N) {
289 const size_t NumFields = ((N + PER_FIELD - 1) / PER_FIELD);
290 const size_t Size = align(sizeof(InitMap)) + NumFields * PER_FIELD;
291 return new (malloc(Size)) InitMap(N);
292}