Bug Summary

File:llvm/include/llvm/Object/MachOUniversal.h
Warning:line 61, column 11
Called C++ object pointer is null

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name MachOUniversal.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 -mframe-pointer=none -fmath-errno -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -fno-split-dwarf-inlining -debugger-tuning=gdb -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-12/lib/clang/12.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-12~++20200926111128+c6c5629f2fb/build-llvm/lib/Object -I /build/llvm-toolchain-snapshot-12~++20200926111128+c6c5629f2fb/llvm/lib/Object -I /build/llvm-toolchain-snapshot-12~++20200926111128+c6c5629f2fb/build-llvm/include -I /build/llvm-toolchain-snapshot-12~++20200926111128+c6c5629f2fb/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-12/lib/clang/12.0.0/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-12~++20200926111128+c6c5629f2fb/build-llvm/lib/Object -fdebug-prefix-map=/build/llvm-toolchain-snapshot-12~++20200926111128+c6c5629f2fb=. -ferror-limit 19 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -o /tmp/scan-build-2020-09-26-161721-17566-1 -x c++ /build/llvm-toolchain-snapshot-12~++20200926111128+c6c5629f2fb/llvm/lib/Object/MachOUniversal.cpp

/build/llvm-toolchain-snapshot-12~++20200926111128+c6c5629f2fb/llvm/lib/Object/MachOUniversal.cpp

1//===- MachOUniversal.cpp - Mach-O universal binary -------------*- 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 the MachOUniversalBinary class.
10//
11//===----------------------------------------------------------------------===//
12
13#include "llvm/Object/MachOUniversal.h"
14#include "llvm/Object/Archive.h"
15#include "llvm/Object/IRObjectFile.h"
16#include "llvm/Object/MachO.h"
17#include "llvm/Object/ObjectFile.h"
18#include "llvm/Support/Casting.h"
19#include "llvm/Support/Host.h"
20#include "llvm/Support/MemoryBuffer.h"
21
22using namespace llvm;
23using namespace object;
24
25static Error
26malformedError(Twine Msg) {
27 std::string StringMsg = "truncated or malformed fat file (" + Msg.str() + ")";
28 return make_error<GenericBinaryError>(std::move(StringMsg),
29 object_error::parse_failed);
30}
31
32template<typename T>
33static T getUniversalBinaryStruct(const char *Ptr) {
34 T Res;
35 memcpy(&Res, Ptr, sizeof(T));
36 // Universal binary headers have big-endian byte order.
37 if (sys::IsLittleEndianHost)
38 swapStruct(Res);
39 return Res;
40}
41
42MachOUniversalBinary::ObjectForArch::ObjectForArch(
43 const MachOUniversalBinary *Parent, uint32_t Index)
44 : Parent(Parent), Index(Index) {
45 // The iterators use Parent as a nullptr and an Index+1 == NumberOfObjects.
46 if (!Parent || Index >= Parent->getNumberOfObjects()) {
47 clear();
48 } else {
49 // Parse object header.
50 StringRef ParentData = Parent->getData();
51 if (Parent->getMagic() == MachO::FAT_MAGIC) {
52 const char *HeaderPos = ParentData.begin() + sizeof(MachO::fat_header) +
53 Index * sizeof(MachO::fat_arch);
54 Header = getUniversalBinaryStruct<MachO::fat_arch>(HeaderPos);
55 } else { // Parent->getMagic() == MachO::FAT_MAGIC_64
56 const char *HeaderPos = ParentData.begin() + sizeof(MachO::fat_header) +
57 Index * sizeof(MachO::fat_arch_64);
58 Header64 = getUniversalBinaryStruct<MachO::fat_arch_64>(HeaderPos);
59 }
60 }
61}
62
63Expected<std::unique_ptr<MachOObjectFile>>
64MachOUniversalBinary::ObjectForArch::getAsObjectFile() const {
65 if (!Parent)
66 report_fatal_error("MachOUniversalBinary::ObjectForArch::getAsObjectFile() "
67 "called when Parent is a nullptr");
68
69 StringRef ParentData = Parent->getData();
70 StringRef ObjectData;
71 uint32_t cputype;
72 if (Parent->getMagic() == MachO::FAT_MAGIC) {
73 ObjectData = ParentData.substr(Header.offset, Header.size);
74 cputype = Header.cputype;
75 } else { // Parent->getMagic() == MachO::FAT_MAGIC_64
76 ObjectData = ParentData.substr(Header64.offset, Header64.size);
77 cputype = Header64.cputype;
78 }
79 StringRef ObjectName = Parent->getFileName();
80 MemoryBufferRef ObjBuffer(ObjectData, ObjectName);
81 return ObjectFile::createMachOObjectFile(ObjBuffer, cputype, Index);
82}
83
84Expected<std::unique_ptr<IRObjectFile>>
85MachOUniversalBinary::ObjectForArch::getAsIRObject(LLVMContext &Ctx) const {
86 if (!Parent)
87 report_fatal_error("MachOUniversalBinary::ObjectForArch::getAsIRObject() "
88 "called when Parent is a nullptr");
89
90 StringRef ParentData = Parent->getData();
91 StringRef ObjectData;
92 if (Parent->getMagic() == MachO::FAT_MAGIC) {
93 ObjectData = ParentData.substr(Header.offset, Header.size);
94 } else { // Parent->getMagic() == MachO::FAT_MAGIC_64
95 ObjectData = ParentData.substr(Header64.offset, Header64.size);
96 }
97 StringRef ObjectName = Parent->getFileName();
98 MemoryBufferRef ObjBuffer(ObjectData, ObjectName);
99
100 return IRObjectFile::create(ObjBuffer, Ctx);
101}
102
103Expected<std::unique_ptr<Archive>>
104MachOUniversalBinary::ObjectForArch::getAsArchive() const {
105 if (!Parent)
106 report_fatal_error("MachOUniversalBinary::ObjectForArch::getAsArchive() "
107 "called when Parent is a nullptr");
108
109 StringRef ParentData = Parent->getData();
110 StringRef ObjectData;
111 if (Parent->getMagic() == MachO::FAT_MAGIC)
112 ObjectData = ParentData.substr(Header.offset, Header.size);
113 else // Parent->getMagic() == MachO::FAT_MAGIC_64
114 ObjectData = ParentData.substr(Header64.offset, Header64.size);
115 StringRef ObjectName = Parent->getFileName();
116 MemoryBufferRef ObjBuffer(ObjectData, ObjectName);
117 return Archive::create(ObjBuffer);
118}
119
120void MachOUniversalBinary::anchor() { }
121
122Expected<std::unique_ptr<MachOUniversalBinary>>
123MachOUniversalBinary::create(MemoryBufferRef Source) {
124 Error Err = Error::success();
125 std::unique_ptr<MachOUniversalBinary> Ret(
126 new MachOUniversalBinary(Source, Err));
127 if (Err)
128 return std::move(Err);
129 return std::move(Ret);
130}
131
132MachOUniversalBinary::MachOUniversalBinary(MemoryBufferRef Source, Error &Err)
133 : Binary(Binary::ID_MachOUniversalBinary, Source), Magic(0),
134 NumberOfObjects(0) {
135 ErrorAsOutParameter ErrAsOutParam(&Err);
136 if (Data.getBufferSize() < sizeof(MachO::fat_header)) {
137 Err = make_error<GenericBinaryError>("File too small to be a Mach-O "
138 "universal file",
139 object_error::invalid_file_type);
140 return;
141 }
142 // Check for magic value and sufficient header size.
143 StringRef Buf = getData();
144 MachO::fat_header H =
145 getUniversalBinaryStruct<MachO::fat_header>(Buf.begin());
146 Magic = H.magic;
147 NumberOfObjects = H.nfat_arch;
148 if (NumberOfObjects == 0) {
149 Err = malformedError("contains zero architecture types");
150 return;
151 }
152 uint32_t MinSize = sizeof(MachO::fat_header);
153 if (Magic == MachO::FAT_MAGIC)
154 MinSize += sizeof(MachO::fat_arch) * NumberOfObjects;
155 else if (Magic == MachO::FAT_MAGIC_64)
156 MinSize += sizeof(MachO::fat_arch_64) * NumberOfObjects;
157 else {
158 Err = malformedError("bad magic number");
159 return;
160 }
161 if (Buf.size() < MinSize) {
162 Err = malformedError("fat_arch" +
163 Twine(Magic == MachO::FAT_MAGIC ? "" : "_64") +
164 " structs would extend past the end of the file");
165 return;
166 }
167 for (uint32_t i = 0; i < NumberOfObjects; i++) {
168 ObjectForArch A(this, i);
169 uint64_t bigSize = A.getOffset();
170 bigSize += A.getSize();
171 if (bigSize > Buf.size()) {
172 Err = malformedError("offset plus size of cputype (" +
173 Twine(A.getCPUType()) + ") cpusubtype (" +
174 Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
175 ") extends past the end of the file");
176 return;
177 }
178
179 if (A.getAlign() > MaxSectionAlignment) {
180 Err = malformedError("align (2^" + Twine(A.getAlign()) +
181 ") too large for cputype (" + Twine(A.getCPUType()) +
182 ") cpusubtype (" +
183 Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
184 ") (maximum 2^" + Twine(MaxSectionAlignment) + ")");
185 return;
186 }
187 if(A.getOffset() % (1ull << A.getAlign()) != 0){
188 Err = malformedError("offset: " + Twine(A.getOffset()) +
189 " for cputype (" + Twine(A.getCPUType()) + ") cpusubtype (" +
190 Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
191 ") not aligned on it's alignment (2^" + Twine(A.getAlign()) + ")");
192 return;
193 }
194 if (A.getOffset() < MinSize) {
195 Err = malformedError("cputype (" + Twine(A.getCPUType()) + ") "
196 "cpusubtype (" + Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
197 ") offset " + Twine(A.getOffset()) + " overlaps universal headers");
198 return;
199 }
200 }
201 for (uint32_t i = 0; i < NumberOfObjects; i++) {
202 ObjectForArch A(this, i);
203 for (uint32_t j = i + 1; j < NumberOfObjects; j++) {
204 ObjectForArch B(this, j);
205 if (A.getCPUType() == B.getCPUType() &&
206 (A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) ==
207 (B.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK)) {
208 Err = malformedError("contains two of the same architecture (cputype "
209 "(" + Twine(A.getCPUType()) + ") cpusubtype (" +
210 Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) + "))");
211 return;
212 }
213 if ((A.getOffset() >= B.getOffset() &&
214 A.getOffset() < B.getOffset() + B.getSize()) ||
215 (A.getOffset() + A.getSize() > B.getOffset() &&
216 A.getOffset() + A.getSize() < B.getOffset() + B.getSize()) ||
217 (A.getOffset() <= B.getOffset() &&
218 A.getOffset() + A.getSize() >= B.getOffset() + B.getSize())) {
219 Err = malformedError("cputype (" + Twine(A.getCPUType()) + ") "
220 "cpusubtype (" + Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
221 ") at offset " + Twine(A.getOffset()) + " with a size of " +
222 Twine(A.getSize()) + ", overlaps cputype (" + Twine(B.getCPUType()) +
223 ") cpusubtype (" + Twine(B.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK)
224 + ") at offset " + Twine(B.getOffset()) + " with a size of "
225 + Twine(B.getSize()));
226 return;
227 }
228 }
229 }
230 Err = Error::success();
231}
232
233Expected<MachOUniversalBinary::ObjectForArch>
234MachOUniversalBinary::getObjectForArch(StringRef ArchName) const {
235 if (Triple(ArchName).getArch() == Triple::ArchType::UnknownArch)
2
Assuming the condition is false
3
Taking false branch
236 return make_error<GenericBinaryError>("Unknown architecture "
237 "named: " +
238 ArchName,
239 object_error::arch_not_found);
240 for (const auto &Obj : objects())
6
Calling 'object_iterator::operator++'
8
Returning from 'object_iterator::operator++'
241 if (Obj.getArchFlagName() == ArchName)
4
Assuming the condition is false
5
Taking false branch
9
Calling 'ObjectForArch::getArchFlagName'
242 return Obj;
243 return make_error<GenericBinaryError>("fat file does not "
244 "contain " +
245 ArchName,
246 object_error::arch_not_found);
247}
248
249Expected<std::unique_ptr<MachOObjectFile>>
250MachOUniversalBinary::getMachOObjectForArch(StringRef ArchName) const {
251 Expected<ObjectForArch> O = getObjectForArch(ArchName);
252 if (!O)
253 return O.takeError();
254 return O->getAsObjectFile();
255}
256
257Expected<std::unique_ptr<IRObjectFile>>
258MachOUniversalBinary::getIRObjectForArch(StringRef ArchName,
259 LLVMContext &Ctx) const {
260 Expected<ObjectForArch> O = getObjectForArch(ArchName);
261 if (!O)
262 return O.takeError();
263 return O->getAsIRObject(Ctx);
264}
265
266Expected<std::unique_ptr<Archive>>
267MachOUniversalBinary::getArchiveForArch(StringRef ArchName) const {
268 Expected<ObjectForArch> O = getObjectForArch(ArchName);
1
Calling 'MachOUniversalBinary::getObjectForArch'
269 if (!O)
270 return O.takeError();
271 return O->getAsArchive();
272}

/build/llvm-toolchain-snapshot-12~++20200926111128+c6c5629f2fb/llvm/include/llvm/Object/MachOUniversal.h

1//===- MachOUniversal.h - Mach-O universal binaries -------------*- 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 declares Mach-O fat/universal binaries.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_OBJECT_MACHOUNIVERSAL_H
14#define LLVM_OBJECT_MACHOUNIVERSAL_H
15
16#include "llvm/ADT/Triple.h"
17#include "llvm/ADT/iterator_range.h"
18#include "llvm/BinaryFormat/MachO.h"
19#include "llvm/Object/Archive.h"
20#include "llvm/Object/Binary.h"
21#include "llvm/Object/MachO.h"
22
23namespace llvm {
24class StringRef;
25class Module;
26class LLVMContext;
27
28namespace object {
29class IRObjectFile;
30
31class MachOUniversalBinary : public Binary {
32 virtual void anchor();
33
34 uint32_t Magic;
35 uint32_t NumberOfObjects;
36public:
37 static constexpr uint32_t MaxSectionAlignment = 15; /* 2**15 or 0x8000 */
38
39 class ObjectForArch {
40 const MachOUniversalBinary *Parent;
41 /// Index of object in the universal binary.
42 uint32_t Index;
43 /// Descriptor of the object.
44 MachO::fat_arch Header;
45 MachO::fat_arch_64 Header64;
46
47 public:
48 ObjectForArch(const MachOUniversalBinary *Parent, uint32_t Index);
49
50 void clear() {
51 Parent = nullptr;
52 Index = 0;
53 }
54
55 bool operator==(const ObjectForArch &Other) const {
56 return (Parent == Other.Parent) && (Index == Other.Index);
57 }
58
59 ObjectForArch getNext() const { return ObjectForArch(Parent, Index + 1); }
60 uint32_t getCPUType() const {
61 if (Parent->getMagic() == MachO::FAT_MAGIC)
11
Called C++ object pointer is null
62 return Header.cputype;
63 else // Parent->getMagic() == MachO::FAT_MAGIC_64
64 return Header64.cputype;
65 }
66 uint32_t getCPUSubType() const {
67 if (Parent->getMagic() == MachO::FAT_MAGIC)
68 return Header.cpusubtype;
69 else // Parent->getMagic() == MachO::FAT_MAGIC_64
70 return Header64.cpusubtype;
71 }
72 uint64_t getOffset() const {
73 if (Parent->getMagic() == MachO::FAT_MAGIC)
74 return Header.offset;
75 else // Parent->getMagic() == MachO::FAT_MAGIC_64
76 return Header64.offset;
77 }
78 uint64_t getSize() const {
79 if (Parent->getMagic() == MachO::FAT_MAGIC)
80 return Header.size;
81 else // Parent->getMagic() == MachO::FAT_MAGIC_64
82 return Header64.size;
83 }
84 uint32_t getAlign() const {
85 if (Parent->getMagic() == MachO::FAT_MAGIC)
86 return Header.align;
87 else // Parent->getMagic() == MachO::FAT_MAGIC_64
88 return Header64.align;
89 }
90 uint32_t getReserved() const {
91 if (Parent->getMagic() == MachO::FAT_MAGIC)
92 return 0;
93 else // Parent->getMagic() == MachO::FAT_MAGIC_64
94 return Header64.reserved;
95 }
96 Triple getTriple() const {
97 return MachOObjectFile::getArchTriple(getCPUType(), getCPUSubType());
98 }
99 std::string getArchFlagName() const {
100 const char *McpuDefault, *ArchFlag;
101 MachOObjectFile::getArchTriple(getCPUType(), getCPUSubType(),
10
Calling 'ObjectForArch::getCPUType'
102 &McpuDefault, &ArchFlag);
103 return ArchFlag ? ArchFlag : std::string();
104 }
105
106 Expected<std::unique_ptr<MachOObjectFile>> getAsObjectFile() const;
107 Expected<std::unique_ptr<IRObjectFile>>
108 getAsIRObject(LLVMContext &Ctx) const;
109
110 Expected<std::unique_ptr<Archive>> getAsArchive() const;
111 };
112
113 class object_iterator {
114 ObjectForArch Obj;
115 public:
116 object_iterator(const ObjectForArch &Obj) : Obj(Obj) {}
117 const ObjectForArch *operator->() const { return &Obj; }
118 const ObjectForArch &operator*() const { return Obj; }
119
120 bool operator==(const object_iterator &Other) const {
121 return Obj == Other.Obj;
122 }
123 bool operator!=(const object_iterator &Other) const {
124 return !(*this == Other);
125 }
126
127 object_iterator& operator++() { // Preincrement
128 Obj = Obj.getNext();
7
Null pointer value stored to '__begin1.Obj.Parent'
129 return *this;
130 }
131 };
132
133 MachOUniversalBinary(MemoryBufferRef Souce, Error &Err);
134 static Expected<std::unique_ptr<MachOUniversalBinary>>
135 create(MemoryBufferRef Source);
136
137 object_iterator begin_objects() const {
138 return ObjectForArch(this, 0);
139 }
140 object_iterator end_objects() const {
141 return ObjectForArch(nullptr, 0);
142 }
143
144 iterator_range<object_iterator> objects() const {
145 return make_range(begin_objects(), end_objects());
146 }
147
148 uint32_t getMagic() const { return Magic; }
149 uint32_t getNumberOfObjects() const { return NumberOfObjects; }
150
151 // Cast methods.
152 static bool classof(Binary const *V) {
153 return V->isMachOUniversalBinary();
154 }
155
156 Expected<ObjectForArch>
157 getObjectForArch(StringRef ArchName) const;
158
159 Expected<std::unique_ptr<MachOObjectFile>>
160 getMachOObjectForArch(StringRef ArchName) const;
161
162 Expected<std::unique_ptr<IRObjectFile>>
163 getIRObjectForArch(StringRef ArchName, LLVMContext &Ctx) const;
164
165 Expected<std::unique_ptr<Archive>>
166 getArchiveForArch(StringRef ArchName) const;
167};
168
169}
170}
171
172#endif