Bug Summary

File:tools/llvm-readobj/Win64EHDumper.cpp
Warning:line 293, column 9
1st function call argument is an uninitialized value

Annotated Source Code

Press '?' to see keyboard shortcuts

clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name Win64EHDumper.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-eagerly-assume -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 -mrelocation-model pic -pic-level 2 -mthread-model posix -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -momit-leaf-frame-pointer -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-7/lib/clang/7.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-7~svn338205/build-llvm/tools/llvm-readobj -I /build/llvm-toolchain-snapshot-7~svn338205/tools/llvm-readobj -I /build/llvm-toolchain-snapshot-7~svn338205/build-llvm/include -I /build/llvm-toolchain-snapshot-7~svn338205/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/8/../../../../include/x86_64-linux-gnu/c++/8 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/8/../../../../include/x86_64-linux-gnu/c++/8 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/backward -internal-isystem /usr/include/clang/7.0.0/include/ -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-7/lib/clang/7.0.0/include -internal-externc-isystem /usr/lib/gcc/x86_64-linux-gnu/8/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-class-memaccess -Wno-comment -std=c++11 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-7~svn338205/build-llvm/tools/llvm-readobj -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -o /tmp/scan-build-2018-07-29-043837-17923-1 -x c++ /build/llvm-toolchain-snapshot-7~svn338205/tools/llvm-readobj/Win64EHDumper.cpp -faddrsig
1//===- Win64EHDumper.cpp - Win64 EH Printer ---------------------*- C++ -*-===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10#include "Win64EHDumper.h"
11#include "llvm-readobj.h"
12#include "llvm/Object/COFF.h"
13#include "llvm/Support/ErrorHandling.h"
14#include "llvm/Support/Format.h"
15
16using namespace llvm;
17using namespace llvm::object;
18using namespace llvm::Win64EH;
19
20static const EnumEntry<unsigned> UnwindFlags[] = {
21 { "ExceptionHandler", UNW_ExceptionHandler },
22 { "TerminateHandler", UNW_TerminateHandler },
23 { "ChainInfo" , UNW_ChainInfo }
24};
25
26static const EnumEntry<unsigned> UnwindOpInfo[] = {
27 { "RAX", 0 },
28 { "RCX", 1 },
29 { "RDX", 2 },
30 { "RBX", 3 },
31 { "RSP", 4 },
32 { "RBP", 5 },
33 { "RSI", 6 },
34 { "RDI", 7 },
35 { "R8", 8 },
36 { "R9", 9 },
37 { "R10", 10 },
38 { "R11", 11 },
39 { "R12", 12 },
40 { "R13", 13 },
41 { "R14", 14 },
42 { "R15", 15 }
43};
44
45static uint64_t getOffsetOfLSDA(const UnwindInfo& UI) {
46 return static_cast<const char*>(UI.getLanguageSpecificData())
47 - reinterpret_cast<const char*>(&UI);
48}
49
50static uint32_t getLargeSlotValue(ArrayRef<UnwindCode> UC) {
51 if (UC.size() < 3)
52 return 0;
53 return UC[1].FrameOffset + (static_cast<uint32_t>(UC[2].FrameOffset) << 16);
54}
55
56// Returns the name of the unwind code.
57static StringRef getUnwindCodeTypeName(uint8_t Code) {
58 switch (Code) {
59 default: llvm_unreachable("Invalid unwind code")::llvm::llvm_unreachable_internal("Invalid unwind code", "/build/llvm-toolchain-snapshot-7~svn338205/tools/llvm-readobj/Win64EHDumper.cpp"
, 59)
;
60 case UOP_PushNonVol: return "PUSH_NONVOL";
61 case UOP_AllocLarge: return "ALLOC_LARGE";
62 case UOP_AllocSmall: return "ALLOC_SMALL";
63 case UOP_SetFPReg: return "SET_FPREG";
64 case UOP_SaveNonVol: return "SAVE_NONVOL";
65 case UOP_SaveNonVolBig: return "SAVE_NONVOL_FAR";
66 case UOP_SaveXMM128: return "SAVE_XMM128";
67 case UOP_SaveXMM128Big: return "SAVE_XMM128_FAR";
68 case UOP_PushMachFrame: return "PUSH_MACHFRAME";
69 }
70}
71
72// Returns the name of a referenced register.
73static StringRef getUnwindRegisterName(uint8_t Reg) {
74 switch (Reg) {
75 default: llvm_unreachable("Invalid register")::llvm::llvm_unreachable_internal("Invalid register", "/build/llvm-toolchain-snapshot-7~svn338205/tools/llvm-readobj/Win64EHDumper.cpp"
, 75)
;
76 case 0: return "RAX";
77 case 1: return "RCX";
78 case 2: return "RDX";
79 case 3: return "RBX";
80 case 4: return "RSP";
81 case 5: return "RBP";
82 case 6: return "RSI";
83 case 7: return "RDI";
84 case 8: return "R8";
85 case 9: return "R9";
86 case 10: return "R10";
87 case 11: return "R11";
88 case 12: return "R12";
89 case 13: return "R13";
90 case 14: return "R14";
91 case 15: return "R15";
92 }
93}
94
95// Calculates the number of array slots required for the unwind code.
96static unsigned getNumUsedSlots(const UnwindCode &UnwindCode) {
97 switch (UnwindCode.getUnwindOp()) {
98 default: llvm_unreachable("Invalid unwind code")::llvm::llvm_unreachable_internal("Invalid unwind code", "/build/llvm-toolchain-snapshot-7~svn338205/tools/llvm-readobj/Win64EHDumper.cpp"
, 98)
;
99 case UOP_PushNonVol:
100 case UOP_AllocSmall:
101 case UOP_SetFPReg:
102 case UOP_PushMachFrame:
103 return 1;
104 case UOP_SaveNonVol:
105 case UOP_SaveXMM128:
106 return 2;
107 case UOP_SaveNonVolBig:
108 case UOP_SaveXMM128Big:
109 return 3;
110 case UOP_AllocLarge:
111 return (UnwindCode.getOpInfo() == 0) ? 2 : 3;
112 }
113}
114
115static std::string formatSymbol(const Dumper::Context &Ctx,
116 const coff_section *Section, uint64_t Offset,
117 uint32_t Displacement) {
118 std::string Buffer;
119 raw_string_ostream OS(Buffer);
120
121 SymbolRef Symbol;
122 if (!Ctx.ResolveSymbol(Section, Offset, Symbol, Ctx.UserData)) {
123 Expected<StringRef> Name = Symbol.getName();
124 if (Name) {
125 OS << *Name;
126 if (Displacement > 0)
127 OS << format(" +0x%X (0x%" PRIX64"l" "X" ")", Displacement, Offset);
128 else
129 OS << format(" (0x%" PRIX64"l" "X" ")", Offset);
130 return OS.str();
131 } else {
132 // TODO: Actually report errors helpfully.
133 consumeError(Name.takeError());
134 }
135 }
136
137 OS << format(" (0x%" PRIX64"l" "X" ")", Offset);
138 return OS.str();
139}
140
141static std::error_code resolveRelocation(const Dumper::Context &Ctx,
142 const coff_section *Section,
143 uint64_t Offset,
144 const coff_section *&ResolvedSection,
145 uint64_t &ResolvedAddress) {
146 SymbolRef Symbol;
147 if (std::error_code EC =
8
Taking true branch
148 Ctx.ResolveSymbol(Section, Offset, Symbol, Ctx.UserData))
149 return EC;
9
Returning without writing to 'ResolvedSection'
150
151 Expected<uint64_t> ResolvedAddressOrErr = Symbol.getAddress();
152 if (!ResolvedAddressOrErr)
153 return errorToErrorCode(ResolvedAddressOrErr.takeError());
154 ResolvedAddress = *ResolvedAddressOrErr;
155
156 Expected<section_iterator> SI = Symbol.getSection();
157 if (!SI)
158 return errorToErrorCode(SI.takeError());
159 ResolvedSection = Ctx.COFF.getCOFFSection(**SI);
160 return std::error_code();
161}
162
163namespace llvm {
164namespace Win64EH {
165void Dumper::printRuntimeFunctionEntry(const Context &Ctx,
166 const coff_section *Section,
167 uint64_t Offset,
168 const RuntimeFunction &RF) {
169 SW.printString("StartAddress",
170 formatSymbol(Ctx, Section, Offset + 0, RF.StartAddress));
171 SW.printString("EndAddress",
172 formatSymbol(Ctx, Section, Offset + 4, RF.EndAddress));
173 SW.printString("UnwindInfoAddress",
174 formatSymbol(Ctx, Section, Offset + 8, RF.UnwindInfoOffset));
175}
176
177// Prints one unwind code. Because an unwind code can occupy up to 3 slots in
178// the unwind codes array, this function requires that the correct number of
179// slots is provided.
180void Dumper::printUnwindCode(const UnwindInfo& UI, ArrayRef<UnwindCode> UC) {
181 assert(UC.size() >= getNumUsedSlots(UC[0]))(static_cast <bool> (UC.size() >= getNumUsedSlots(UC
[0])) ? void (0) : __assert_fail ("UC.size() >= getNumUsedSlots(UC[0])"
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/llvm-readobj/Win64EHDumper.cpp"
, 181, __extension__ __PRETTY_FUNCTION__))
;
182
183 SW.startLine() << format("0x%02X: ", unsigned(UC[0].u.CodeOffset))
184 << getUnwindCodeTypeName(UC[0].getUnwindOp());
185
186 switch (UC[0].getUnwindOp()) {
187 case UOP_PushNonVol:
188 OS << " reg=" << getUnwindRegisterName(UC[0].getOpInfo());
189 break;
190
191 case UOP_AllocLarge:
192 OS << " size="
193 << ((UC[0].getOpInfo() == 0) ? UC[1].FrameOffset * 8
194 : getLargeSlotValue(UC));
195 break;
196
197 case UOP_AllocSmall:
198 OS << " size=" << (UC[0].getOpInfo() + 1) * 8;
199 break;
200
201 case UOP_SetFPReg:
202 if (UI.getFrameRegister() == 0)
203 OS << " reg=<invalid>";
204 else
205 OS << " reg=" << getUnwindRegisterName(UI.getFrameRegister())
206 << format(", offset=0x%X", UI.getFrameOffset() * 16);
207 break;
208
209 case UOP_SaveNonVol:
210 OS << " reg=" << getUnwindRegisterName(UC[0].getOpInfo())
211 << format(", offset=0x%X", UC[1].FrameOffset * 8);
212 break;
213
214 case UOP_SaveNonVolBig:
215 OS << " reg=" << getUnwindRegisterName(UC[0].getOpInfo())
216 << format(", offset=0x%X", getLargeSlotValue(UC));
217 break;
218
219 case UOP_SaveXMM128:
220 OS << " reg=XMM" << static_cast<uint32_t>(UC[0].getOpInfo())
221 << format(", offset=0x%X", UC[1].FrameOffset * 16);
222 break;
223
224 case UOP_SaveXMM128Big:
225 OS << " reg=XMM" << static_cast<uint32_t>(UC[0].getOpInfo())
226 << format(", offset=0x%X", getLargeSlotValue(UC));
227 break;
228
229 case UOP_PushMachFrame:
230 OS << " errcode=" << (UC[0].getOpInfo() == 0 ? "no" : "yes");
231 break;
232 }
233
234 OS << "\n";
235}
236
237void Dumper::printUnwindInfo(const Context &Ctx, const coff_section *Section,
238 off_t Offset, const UnwindInfo &UI) {
239 DictScope UIS(SW, "UnwindInfo");
240 SW.printNumber("Version", UI.getVersion());
241 SW.printFlags("Flags", UI.getFlags(), makeArrayRef(UnwindFlags));
242 SW.printNumber("PrologSize", UI.PrologSize);
243 if (UI.getFrameRegister()) {
244 SW.printEnum("FrameRegister", UI.getFrameRegister(),
245 makeArrayRef(UnwindOpInfo));
246 SW.printHex("FrameOffset", UI.getFrameOffset());
247 } else {
248 SW.printString("FrameRegister", StringRef("-"));
249 SW.printString("FrameOffset", StringRef("-"));
250 }
251
252 SW.printNumber("UnwindCodeCount", UI.NumCodes);
253 {
254 ListScope UCS(SW, "UnwindCodes");
255 ArrayRef<UnwindCode> UC(&UI.UnwindCodes[0], UI.NumCodes);
256 for (const UnwindCode *UCI = UC.begin(), *UCE = UC.end(); UCI < UCE; ++UCI) {
257 unsigned UsedSlots = getNumUsedSlots(*UCI);
258 if (UsedSlots > UC.size()) {
259 errs() << "corrupt unwind data";
260 return;
261 }
262
263 printUnwindCode(UI, makeArrayRef(UCI, UCE));
264 UCI = UCI + UsedSlots - 1;
265 }
266 }
267
268 uint64_t LSDAOffset = Offset + getOffsetOfLSDA(UI);
269 if (UI.getFlags() & (UNW_ExceptionHandler | UNW_TerminateHandler)) {
270 SW.printString("Handler",
271 formatSymbol(Ctx, Section, LSDAOffset,
272 UI.getLanguageSpecificHandlerOffset()));
273 } else if (UI.getFlags() & UNW_ChainInfo) {
274 if (const RuntimeFunction *Chained = UI.getChainedFunctionEntry()) {
275 DictScope CS(SW, "Chained");
276 printRuntimeFunctionEntry(Ctx, Section, LSDAOffset, *Chained);
277 }
278 }
279}
280
281void Dumper::printRuntimeFunction(const Context &Ctx,
282 const coff_section *Section,
283 uint64_t SectionOffset,
284 const RuntimeFunction &RF) {
285 DictScope RFS(SW, "RuntimeFunction");
286 printRuntimeFunctionEntry(Ctx, Section, SectionOffset, RF);
287
288 const coff_section *XData;
6
'XData' declared without an initial value
289 uint64_t Offset;
290 resolveRelocation(Ctx, Section, SectionOffset + 8, XData, Offset);
7
Calling 'resolveRelocation'
10
Returning from 'resolveRelocation'
291
292 ArrayRef<uint8_t> Contents;
293 error(Ctx.COFF.getSectionContents(XData, Contents));
11
1st function call argument is an uninitialized value
294 if (Contents.empty())
295 return;
296
297 Offset = Offset + RF.UnwindInfoOffset;
298 if (Offset > Contents.size())
299 return;
300
301 const auto UI = reinterpret_cast<const UnwindInfo*>(Contents.data() + Offset);
302 printUnwindInfo(Ctx, XData, Offset, *UI);
303}
304
305void Dumper::printData(const Context &Ctx) {
306 for (const auto &Section : Ctx.COFF.sections()) {
307 StringRef Name;
308 Section.getName(Name);
309
310 if (Name != ".pdata" && !Name.startswith(".pdata$"))
1
Taking false branch
311 continue;
312
313 const coff_section *PData = Ctx.COFF.getCOFFSection(Section);
314 ArrayRef<uint8_t> Contents;
315 error(Ctx.COFF.getSectionContents(PData, Contents));
316 if (Contents.empty())
2
Assuming the condition is false
3
Taking false branch
317 continue;
318
319 const RuntimeFunction *Entries =
320 reinterpret_cast<const RuntimeFunction *>(Contents.data());
321 const size_t Count = Contents.size() / sizeof(RuntimeFunction);
322 ArrayRef<RuntimeFunction> RuntimeFunctions(Entries, Count);
323
324 size_t Index = 0;
325 for (const auto &RF : RuntimeFunctions) {
4
Assuming '__begin3' is not equal to '__end3'
326 printRuntimeFunction(Ctx, Ctx.COFF.getCOFFSection(Section),
5
Calling 'Dumper::printRuntimeFunction'
327 Index * sizeof(RuntimeFunction), RF);
328 ++Index;
329 }
330 }
331}
332}
333}
334