Bug Summary

File:llvm/include/llvm/Object/MachOUniversal.h
Warning:line 95, column 11
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 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 -mthread-model posix -mframe-pointer=none -fmath-errno -fno-rounding-math -masm-verbose -mconstructor-aliases -munwind-tables -target-cpu x86-64 -dwarf-column-info -fno-split-dwarf-inlining -debugger-tuning=gdb -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-11/lib/clang/11.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/build-llvm/lib/Object -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Object -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/build-llvm/include -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/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-11/lib/clang/11.0.0/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-11~++20200309111110+2c36c23f347/build-llvm/lib/Object -fdebug-prefix-map=/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347=. -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -o /tmp/scan-build-2020-03-09-184146-41876-1 -x c++ /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Object/MachOUniversal.cpp

/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/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/MachO.h"
16#include "llvm/Object/ObjectFile.h"
17#include "llvm/Support/Casting.h"
18#include "llvm/Support/Host.h"
19#include "llvm/Support/MemoryBuffer.h"
20
21using namespace llvm;
22using namespace object;
23
24static Error
25malformedError(Twine Msg) {
26 std::string StringMsg = "truncated or malformed fat file (" + Msg.str() + ")";
27 return make_error<GenericBinaryError>(std::move(StringMsg),
28 object_error::parse_failed);
29}
30
31template<typename T>
32static T getUniversalBinaryStruct(const char *Ptr) {
33 T Res;
34 memcpy(&Res, Ptr, sizeof(T));
35 // Universal binary headers have big-endian byte order.
36 if (sys::IsLittleEndianHost)
37 swapStruct(Res);
38 return Res;
39}
40
41MachOUniversalBinary::ObjectForArch::ObjectForArch(
42 const MachOUniversalBinary *Parent, uint32_t Index)
43 : Parent(Parent), Index(Index) {
44 // The iterators use Parent as a nullptr and an Index+1 == NumberOfObjects.
45 if (!Parent || Index >= Parent->getNumberOfObjects()) {
46 clear();
47 } else {
48 // Parse object header.
49 StringRef ParentData = Parent->getData();
50 if (Parent->getMagic() == MachO::FAT_MAGIC) {
51 const char *HeaderPos = ParentData.begin() + sizeof(MachO::fat_header) +
52 Index * sizeof(MachO::fat_arch);
53 Header = getUniversalBinaryStruct<MachO::fat_arch>(HeaderPos);
54 } else { // Parent->getMagic() == MachO::FAT_MAGIC_64
55 const char *HeaderPos = ParentData.begin() + sizeof(MachO::fat_header) +
56 Index * sizeof(MachO::fat_arch_64);
57 Header64 = getUniversalBinaryStruct<MachO::fat_arch_64>(HeaderPos);
58 }
59 }
60}
61
62Expected<std::unique_ptr<MachOObjectFile>>
63MachOUniversalBinary::ObjectForArch::getAsObjectFile() const {
64 if (!Parent)
65 report_fatal_error("MachOUniversalBinary::ObjectForArch::getAsObjectFile() "
66 "called when Parent is a nullptr");
67
68 StringRef ParentData = Parent->getData();
69 StringRef ObjectData;
70 uint32_t cputype;
71 if (Parent->getMagic() == MachO::FAT_MAGIC) {
72 ObjectData = ParentData.substr(Header.offset, Header.size);
73 cputype = Header.cputype;
74 } else { // Parent->getMagic() == MachO::FAT_MAGIC_64
75 ObjectData = ParentData.substr(Header64.offset, Header64.size);
76 cputype = Header64.cputype;
77 }
78 StringRef ObjectName = Parent->getFileName();
79 MemoryBufferRef ObjBuffer(ObjectData, ObjectName);
80 return ObjectFile::createMachOObjectFile(ObjBuffer, cputype, Index);
81}
82
83Expected<std::unique_ptr<Archive>>
84MachOUniversalBinary::ObjectForArch::getAsArchive() const {
85 if (!Parent)
86 report_fatal_error("MachOUniversalBinary::ObjectForArch::getAsArchive() "
87 "called when Parent is a nullptr");
88
89 StringRef ParentData = Parent->getData();
90 StringRef ObjectData;
91 if (Parent->getMagic() == MachO::FAT_MAGIC)
92 ObjectData = ParentData.substr(Header.offset, Header.size);
93 else // Parent->getMagic() == MachO::FAT_MAGIC_64
94 ObjectData = ParentData.substr(Header64.offset, Header64.size);
95 StringRef ObjectName = Parent->getFileName();
96 MemoryBufferRef ObjBuffer(ObjectData, ObjectName);
97 return Archive::create(ObjBuffer);
98}
99
100void MachOUniversalBinary::anchor() { }
101
102Expected<std::unique_ptr<MachOUniversalBinary>>
103MachOUniversalBinary::create(MemoryBufferRef Source) {
104 Error Err = Error::success();
105 std::unique_ptr<MachOUniversalBinary> Ret(
106 new MachOUniversalBinary(Source, Err));
107 if (Err)
108 return std::move(Err);
109 return std::move(Ret);
110}
111
112MachOUniversalBinary::MachOUniversalBinary(MemoryBufferRef Source, Error &Err)
113 : Binary(Binary::ID_MachOUniversalBinary, Source), Magic(0),
114 NumberOfObjects(0) {
115 ErrorAsOutParameter ErrAsOutParam(&Err);
116 if (Data.getBufferSize() < sizeof(MachO::fat_header)) {
117 Err = make_error<GenericBinaryError>("File too small to be a Mach-O "
118 "universal file",
119 object_error::invalid_file_type);
120 return;
121 }
122 // Check for magic value and sufficient header size.
123 StringRef Buf = getData();
124 MachO::fat_header H =
125 getUniversalBinaryStruct<MachO::fat_header>(Buf.begin());
126 Magic = H.magic;
127 NumberOfObjects = H.nfat_arch;
128 if (NumberOfObjects == 0) {
129 Err = malformedError("contains zero architecture types");
130 return;
131 }
132 uint32_t MinSize = sizeof(MachO::fat_header);
133 if (Magic == MachO::FAT_MAGIC)
134 MinSize += sizeof(MachO::fat_arch) * NumberOfObjects;
135 else if (Magic == MachO::FAT_MAGIC_64)
136 MinSize += sizeof(MachO::fat_arch_64) * NumberOfObjects;
137 else {
138 Err = malformedError("bad magic number");
139 return;
140 }
141 if (Buf.size() < MinSize) {
142 Err = malformedError("fat_arch" +
143 Twine(Magic == MachO::FAT_MAGIC ? "" : "_64") +
144 " structs would extend past the end of the file");
145 return;
146 }
147 for (uint32_t i = 0; i < NumberOfObjects; i++) {
148 ObjectForArch A(this, i);
149 uint64_t bigSize = A.getOffset();
150 bigSize += A.getSize();
151 if (bigSize > Buf.size()) {
152 Err = malformedError("offset plus size of cputype (" +
153 Twine(A.getCPUType()) + ") cpusubtype (" +
154 Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
155 ") extends past the end of the file");
156 return;
157 }
158
159 if (A.getAlign() > MaxSectionAlignment) {
160 Err = malformedError("align (2^" + Twine(A.getAlign()) +
161 ") too large for cputype (" + Twine(A.getCPUType()) +
162 ") cpusubtype (" +
163 Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
164 ") (maximum 2^" + Twine(MaxSectionAlignment) + ")");
165 return;
166 }
167 if(A.getOffset() % (1ull << A.getAlign()) != 0){
168 Err = malformedError("offset: " + Twine(A.getOffset()) +
169 " for cputype (" + Twine(A.getCPUType()) + ") cpusubtype (" +
170 Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
171 ") not aligned on it's alignment (2^" + Twine(A.getAlign()) + ")");
172 return;
173 }
174 if (A.getOffset() < MinSize) {
175 Err = malformedError("cputype (" + Twine(A.getCPUType()) + ") "
176 "cpusubtype (" + Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
177 ") offset " + Twine(A.getOffset()) + " overlaps universal headers");
178 return;
179 }
180 }
181 for (uint32_t i = 0; i < NumberOfObjects; i++) {
182 ObjectForArch A(this, i);
183 for (uint32_t j = i + 1; j < NumberOfObjects; j++) {
184 ObjectForArch B(this, j);
185 if (A.getCPUType() == B.getCPUType() &&
186 (A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) ==
187 (B.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK)) {
188 Err = malformedError("contains two of the same architecture (cputype "
189 "(" + Twine(A.getCPUType()) + ") cpusubtype (" +
190 Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) + "))");
191 return;
192 }
193 if ((A.getOffset() >= B.getOffset() &&
194 A.getOffset() < B.getOffset() + B.getSize()) ||
195 (A.getOffset() + A.getSize() > B.getOffset() &&
196 A.getOffset() + A.getSize() < B.getOffset() + B.getSize()) ||
197 (A.getOffset() <= B.getOffset() &&
198 A.getOffset() + A.getSize() >= B.getOffset() + B.getSize())) {
199 Err = malformedError("cputype (" + Twine(A.getCPUType()) + ") "
200 "cpusubtype (" + Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
201 ") at offset " + Twine(A.getOffset()) + " with a size of " +
202 Twine(A.getSize()) + ", overlaps cputype (" + Twine(B.getCPUType()) +
203 ") cpusubtype (" + Twine(B.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK)
204 + ") at offset " + Twine(B.getOffset()) + " with a size of "
205 + Twine(B.getSize()));
206 return;
207 }
208 }
209 }
210 Err = Error::success();
211}
212
213Expected<MachOUniversalBinary::ObjectForArch>
214MachOUniversalBinary::getObjectForArch(StringRef ArchName) const {
215 if (Triple(ArchName).getArch() == Triple::ArchType::UnknownArch)
2
←
Assuming the condition is false
→
3
←
Taking false branch
→
216 return make_error<GenericBinaryError>("Unknown architecture "
217 "named: " +
218 ArchName,
219 object_error::arch_not_found);
220 for (const auto &Obj : objects())
6
←
Calling 'object_iterator::operator++'
→
8
←
Returning from 'object_iterator::operator++'
→
221 if (Obj.getArchFlagName() == ArchName)
4
←
Assuming the condition is false
→
5
←
Taking false branch
→
9
←
Calling 'ObjectForArch::getArchFlagName'
→
222 return Obj;
223 return make_error<GenericBinaryError>("fat file does not "
224 "contain " +
225 ArchName,
226 object_error::arch_not_found);
227}
228
229Expected<std::unique_ptr<MachOObjectFile>>
230MachOUniversalBinary::getMachOObjectForArch(StringRef ArchName) const {
231 Expected<ObjectForArch> O = getObjectForArch(ArchName);
232 if (!O)
233 return O.takeError();
234 return O->getAsObjectFile();
235}
236
237Expected<std::unique_ptr<Archive>>
238MachOUniversalBinary::getArchiveForArch(StringRef ArchName) const {
239 Expected<ObjectForArch> O = getObjectForArch(ArchName);
1
Calling 'MachOUniversalBinary::getObjectForArch'
→
240 if (!O)
241 return O.takeError();
242 return O->getAsArchive();
243}
←

/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/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;
25
26namespace object {
27
28class MachOUniversalBinary : public Binary {
29 virtual void anchor();
30
31 uint32_t Magic;
32 uint32_t NumberOfObjects;
33public:
34 static constexpr uint32_t MaxSectionAlignment = 15; /* 2**15 or 0x8000 */
35
36 class ObjectForArch {
37 const MachOUniversalBinary *Parent;
38 /// Index of object in the universal binary.
39 uint32_t Index;
40 /// Descriptor of the object.
41 MachO::fat_arch Header;
42 MachO::fat_arch_64 Header64;
43
44 public:
45 ObjectForArch(const MachOUniversalBinary *Parent, uint32_t Index);
46
47 void clear() {
48 Parent = nullptr;
49 Index = 0;
50 }
51
52 bool operator==(const ObjectForArch &Other) const {
53 return (Parent == Other.Parent) && (Index == Other.Index);
54 }
55
56 ObjectForArch getNext() const { return ObjectForArch(Parent, Index + 1); }
57 uint32_t getCPUType() const {
58 if (Parent->getMagic() == MachO::FAT_MAGIC)
59 return Header.cputype;
60 else // Parent->getMagic() == MachO::FAT_MAGIC_64
61 return Header64.cputype;
62 }
63 uint32_t getCPUSubType() const {
64 if (Parent->getMagic() == MachO::FAT_MAGIC)
65 return Header.cpusubtype;
66 else // Parent->getMagic() == MachO::FAT_MAGIC_64
67 return Header64.cpusubtype;
68 }
69 uint64_t getOffset() const {
70 if (Parent->getMagic() == MachO::FAT_MAGIC)
71 return Header.offset;
72 else // Parent->getMagic() == MachO::FAT_MAGIC_64
73 return Header64.offset;
74 }
75 uint64_t getSize() const {
76 if (Parent->getMagic() == MachO::FAT_MAGIC)
77 return Header.size;
78 else // Parent->getMagic() == MachO::FAT_MAGIC_64
79 return Header64.size;
80 }
81 uint32_t getAlign() const {
82 if (Parent->getMagic() == MachO::FAT_MAGIC)
83 return Header.align;
84 else // Parent->getMagic() == MachO::FAT_MAGIC_64
85 return Header64.align;
86 }
87 uint32_t getReserved() const {
88 if (Parent->getMagic() == MachO::FAT_MAGIC)
89 return 0;
90 else // Parent->getMagic() == MachO::FAT_MAGIC_64
91 return Header64.reserved;
92 }
93 std::string getArchFlagName() const {
94 const char *McpuDefault, *ArchFlag;
95 if (Parent->getMagic() == MachO::FAT_MAGIC) {
10
←
Called C++ object pointer is null
96 Triple T =
97 MachOObjectFile::getArchTriple(Header.cputype, Header.cpusubtype,
98 &McpuDefault, &ArchFlag);
99 } else { // Parent->getMagic() == MachO::FAT_MAGIC_64
100 Triple T =
101 MachOObjectFile::getArchTriple(Header64.cputype,
102 Header64.cpusubtype,
103 &McpuDefault, &ArchFlag);
104 }
105 if (ArchFlag) {
106 std::string ArchFlagName(ArchFlag);
107 return ArchFlagName;
108 } else {
109 std::string ArchFlagName("");
110 return ArchFlagName;
111 }
112 }
113
114 Expected<std::unique_ptr<MachOObjectFile>> getAsObjectFile() const;
115
116 Expected<std::unique_ptr<Archive>> getAsArchive() const;
117 };
118
119 class object_iterator {
120 ObjectForArch Obj;
121 public:
122 object_iterator(const ObjectForArch &Obj) : Obj(Obj) {}
123 const ObjectForArch *operator->() const { return &Obj; }
124 const ObjectForArch &operator*() const { return Obj; }
125
126 bool operator==(const object_iterator &Other) const {
127 return Obj == Other.Obj;
128 }
129 bool operator!=(const object_iterator &Other) const {
130 return !(*this == Other);
131 }
132
133 object_iterator& operator++() { // Preincrement
134 Obj = Obj.getNext();
7
←
Null pointer value stored to '__begin1.Obj.Parent'
→
135 return *this;
136 }
137 };
138
139 MachOUniversalBinary(MemoryBufferRef Souce, Error &Err);
140 static Expected<std::unique_ptr<MachOUniversalBinary>>
141 create(MemoryBufferRef Source);
142
143 object_iterator begin_objects() const {
144 return ObjectForArch(this, 0);
145 }
146 object_iterator end_objects() const {
147 return ObjectForArch(nullptr, 0);
148 }
149
150 iterator_range<object_iterator> objects() const {
151 return make_range(begin_objects(), end_objects());
152 }
153
154 uint32_t getMagic() const { return Magic; }
155 uint32_t getNumberOfObjects() const { return NumberOfObjects; }
156
157 // Cast methods.
158 static bool classof(Binary const *V) {
159 return V->isMachOUniversalBinary();
160 }
161
162 Expected<ObjectForArch>
163 getObjectForArch(StringRef ArchName) const;
164
165 Expected<std::unique_ptr<MachOObjectFile>>
166 getMachOObjectForArch(StringRef ArchName) const;
167
168 Expected<std::unique_ptr<Archive>>
169 getArchiveForArch(StringRef ArchName) const;
170};
171
172}
173}
174
175#endif