Bug Summary

File:src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/DebugInfo/DWARF/DWARFDebugLine.cpp
Warning:line 802, column 7
Called C++ object pointer is null

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name DWARFDebugLine.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 -mrelocation-model pic -pic-level 1 -fhalf-no-semantic-interposition -mframe-pointer=all -relaxed-aliasing -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/gnu/usr.bin/clang/libLLVM/obj -resource-dir /usr/local/lib/clang/13.0.0 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/AMDGPU -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Analysis -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ASMParser -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/BinaryFormat -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Bitcode -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Bitcode -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Bitstream -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /include/llvm/CodeGen -I /include/llvm/CodeGen/PBQP -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/IR -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/IR -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Coroutines -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ProfileData/Coverage -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/CodeView -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/DWARF -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/MSF -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/PDB -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Demangle -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ExecutionEngine -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ExecutionEngine/JITLink -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ExecutionEngine/Orc -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend/OpenACC -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Frontend/OpenMP -I /include/llvm/CodeGen/GlobalISel -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/IRReader -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/InstCombine -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/Transforms/InstCombine -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/LTO -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Linker -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/MC -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/MC/MCParser -I /include/llvm/CodeGen/MIRParser -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Object -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Option -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Passes -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ProfileData -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Scalar -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ADT -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Support -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/DebugInfo/Symbolize -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Target -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Utils -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/Vectorize -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include/llvm/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Target/X86 -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Transforms/IPO -I /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include -I /usr/src/gnu/usr.bin/clang/libLLVM/../include -I /usr/src/gnu/usr.bin/clang/libLLVM/obj -I /usr/src/gnu/usr.bin/clang/libLLVM/obj/../include -D NDEBUG -D __STDC_LIMIT_MACROS -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D LLVM_PREFIX="/usr" -D PIC -internal-isystem /usr/include/c++/v1 -internal-isystem /usr/local/lib/clang/13.0.0/include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/usr/src/gnu/usr.bin/clang/libLLVM/obj -ferror-limit 19 -fvisibility-inlines-hidden -fwrapv -D_RET_PROTECTOR -ret-protector -fno-rtti -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /home/ben/Projects/vmm/scan-build/2022-01-12-194120-40624-1 -x c++ /usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/DebugInfo/DWARF/DWARFDebugLine.cpp

/usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/DebugInfo/DWARF/DWARFDebugLine.cpp

→
1//===- DWARFDebugLine.cpp -------------------------------------------------===//
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 "llvm/DebugInfo/DWARF/DWARFDebugLine.h"
10#include "llvm/ADT/Optional.h"
11#include "llvm/ADT/SmallString.h"
12#include "llvm/ADT/SmallVector.h"
13#include "llvm/ADT/StringRef.h"
14#include "llvm/BinaryFormat/Dwarf.h"
15#include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
16#include "llvm/DebugInfo/DWARF/DWARFRelocMap.h"
17#include "llvm/Support/Errc.h"
18#include "llvm/Support/Format.h"
19#include "llvm/Support/FormatVariadic.h"
20#include "llvm/Support/WithColor.h"
21#include "llvm/Support/raw_ostream.h"
22#include <algorithm>
23#include <cassert>
24#include <cinttypes>
25#include <cstdint>
26#include <cstdio>
27#include <utility>
28
29using namespace llvm;
30using namespace dwarf;
31
32using FileLineInfoKind = DILineInfoSpecifier::FileLineInfoKind;
33
34namespace {
35
36struct ContentDescriptor {
37 dwarf::LineNumberEntryFormat Type;
38 dwarf::Form Form;
39};
40
41using ContentDescriptors = SmallVector<ContentDescriptor, 4>;
42
43} // end anonymous namespace
44
45static bool versionIsSupported(uint16_t Version) {
46 return Version >= 2 && Version <= 5;
47}
48
49void DWARFDebugLine::ContentTypeTracker::trackContentType(
50 dwarf::LineNumberEntryFormat ContentType) {
51 switch (ContentType) {
52 case dwarf::DW_LNCT_timestamp:
53 HasModTime = true;
54 break;
55 case dwarf::DW_LNCT_size:
56 HasLength = true;
57 break;
58 case dwarf::DW_LNCT_MD5:
59 HasMD5 = true;
60 break;
61 case dwarf::DW_LNCT_LLVM_source:
62 HasSource = true;
63 break;
64 default:
65 // We only care about values we consider optional, and new values may be
66 // added in the vendor extension range, so we do not match exhaustively.
67 break;
68 }
69}
70
71DWARFDebugLine::Prologue::Prologue() { clear(); }
72
73bool DWARFDebugLine::Prologue::hasFileAtIndex(uint64_t FileIndex) const {
74 uint16_t DwarfVersion = getVersion();
75 assert(DwarfVersion != 0 &&((void)0)
76 "line table prologue has no dwarf version information")((void)0);
77 if (DwarfVersion >= 5)
78 return FileIndex < FileNames.size();
79 return FileIndex != 0 && FileIndex <= FileNames.size();
80}
81
82Optional<uint64_t> DWARFDebugLine::Prologue::getLastValidFileIndex() const {
83 if (FileNames.empty())
84 return None;
85 uint16_t DwarfVersion = getVersion();
86 assert(DwarfVersion != 0 &&((void)0)
87 "line table prologue has no dwarf version information")((void)0);
88 // In DWARF v5 the file names are 0-indexed.
89 if (DwarfVersion >= 5)
90 return FileNames.size() - 1;
91 return FileNames.size();
92}
93
94const llvm::DWARFDebugLine::FileNameEntry &
95DWARFDebugLine::Prologue::getFileNameEntry(uint64_t Index) const {
96 uint16_t DwarfVersion = getVersion();
97 assert(DwarfVersion != 0 &&((void)0)
98 "line table prologue has no dwarf version information")((void)0);
99 // In DWARF v5 the file names are 0-indexed.
100 if (DwarfVersion >= 5)
101 return FileNames[Index];
102 return FileNames[Index - 1];
103}
104
105void DWARFDebugLine::Prologue::clear() {
106 TotalLength = PrologueLength = 0;
107 SegSelectorSize = 0;
108 MinInstLength = MaxOpsPerInst = DefaultIsStmt = LineBase = LineRange = 0;
109 OpcodeBase = 0;
110 FormParams = dwarf::FormParams({0, 0, DWARF32});
111 ContentTypes = ContentTypeTracker();
112 StandardOpcodeLengths.clear();
113 IncludeDirectories.clear();
114 FileNames.clear();
115}
116
117void DWARFDebugLine::Prologue::dump(raw_ostream &OS,
118 DIDumpOptions DumpOptions) const {
119 if (!totalLengthIsValid())
120 return;
121 int OffsetDumpWidth = 2 * dwarf::getDwarfOffsetByteSize(FormParams.Format);
122 OS << "Line table prologue:\n"
123 << format(" total_length: 0x%0*" PRIx64"llx" "\n", OffsetDumpWidth,
124 TotalLength)
125 << " format: " << dwarf::FormatString(FormParams.Format) << "\n"
126 << format(" version: %u\n", getVersion());
127 if (!versionIsSupported(getVersion()))
128 return;
129 if (getVersion() >= 5)
130 OS << format(" address_size: %u\n", getAddressSize())
131 << format(" seg_select_size: %u\n", SegSelectorSize);
132 OS << format(" prologue_length: 0x%0*" PRIx64"llx" "\n", OffsetDumpWidth,
133 PrologueLength)
134 << format(" min_inst_length: %u\n", MinInstLength)
135 << format(getVersion() >= 4 ? "max_ops_per_inst: %u\n" : "", MaxOpsPerInst)
136 << format(" default_is_stmt: %u\n", DefaultIsStmt)
137 << format(" line_base: %i\n", LineBase)
138 << format(" line_range: %u\n", LineRange)
139 << format(" opcode_base: %u\n", OpcodeBase);
140
141 for (uint32_t I = 0; I != StandardOpcodeLengths.size(); ++I)
142 OS << formatv("standard_opcode_lengths[{0}] = {1}\n",
143 static_cast<dwarf::LineNumberOps>(I + 1),
144 StandardOpcodeLengths[I]);
145
146 if (!IncludeDirectories.empty()) {
147 // DWARF v5 starts directory indexes at 0.
148 uint32_t DirBase = getVersion() >= 5 ? 0 : 1;
149 for (uint32_t I = 0; I != IncludeDirectories.size(); ++I) {
150 OS << format("include_directories[%3u] = ", I + DirBase);
151 IncludeDirectories[I].dump(OS, DumpOptions);
152 OS << '\n';
153 }
154 }
155
156 if (!FileNames.empty()) {
157 // DWARF v5 starts file indexes at 0.
158 uint32_t FileBase = getVersion() >= 5 ? 0 : 1;
159 for (uint32_t I = 0; I != FileNames.size(); ++I) {
160 const FileNameEntry &FileEntry = FileNames[I];
161 OS << format("file_names[%3u]:\n", I + FileBase);
162 OS << " name: ";
163 FileEntry.Name.dump(OS, DumpOptions);
164 OS << '\n'
165 << format(" dir_index: %" PRIu64"llu" "\n", FileEntry.DirIdx);
166 if (ContentTypes.HasMD5)
167 OS << " md5_checksum: " << FileEntry.Checksum.digest() << '\n';
168 if (ContentTypes.HasModTime)
169 OS << format(" mod_time: 0x%8.8" PRIx64"llx" "\n", FileEntry.ModTime);
170 if (ContentTypes.HasLength)
171 OS << format(" length: 0x%8.8" PRIx64"llx" "\n", FileEntry.Length);
172 if (ContentTypes.HasSource) {
173 OS << " source: ";
174 FileEntry.Source.dump(OS, DumpOptions);
175 OS << '\n';
176 }
177 }
178 }
179}
180
181// Parse v2-v4 directory and file tables.
182static Error
183parseV2DirFileTables(const DWARFDataExtractor &DebugLineData,
184 uint64_t *OffsetPtr,
185 DWARFDebugLine::ContentTypeTracker &ContentTypes,
186 std::vector<DWARFFormValue> &IncludeDirectories,
187 std::vector<DWARFDebugLine::FileNameEntry> &FileNames) {
188 while (true) {
189 Error Err = Error::success();
190 StringRef S = DebugLineData.getCStrRef(OffsetPtr, &Err);
191 if (Err) {
192 consumeError(std::move(Err));
193 return createStringError(errc::invalid_argument,
194 "include directories table was not null "
195 "terminated before the end of the prologue");
196 }
197 if (S.empty())
198 break;
199 DWARFFormValue Dir =
200 DWARFFormValue::createFromPValue(dwarf::DW_FORM_string, S.data());
201 IncludeDirectories.push_back(Dir);
202 }
203
204 ContentTypes.HasModTime = true;
205 ContentTypes.HasLength = true;
206
207 while (true) {
208 Error Err = Error::success();
209 StringRef Name = DebugLineData.getCStrRef(OffsetPtr, &Err);
210 if (!Err && Name.empty())
211 break;
212
213 DWARFDebugLine::FileNameEntry FileEntry;
214 FileEntry.Name =
215 DWARFFormValue::createFromPValue(dwarf::DW_FORM_string, Name.data());
216 FileEntry.DirIdx = DebugLineData.getULEB128(OffsetPtr, &Err);
217 FileEntry.ModTime = DebugLineData.getULEB128(OffsetPtr, &Err);
218 FileEntry.Length = DebugLineData.getULEB128(OffsetPtr, &Err);
219
220 if (Err) {
221 consumeError(std::move(Err));
222 return createStringError(
223 errc::invalid_argument,
224 "file names table was not null terminated before "
225 "the end of the prologue");
226 }
227 FileNames.push_back(FileEntry);
228 }
229
230 return Error::success();
231}
232
233// Parse v5 directory/file entry content descriptions.
234// Returns the descriptors, or an error if we did not find a path or ran off
235// the end of the prologue.
236static llvm::Expected<ContentDescriptors>
237parseV5EntryFormat(const DWARFDataExtractor &DebugLineData, uint64_t *OffsetPtr,
238 DWARFDebugLine::ContentTypeTracker *ContentTypes) {
239 Error Err = Error::success();
240 ContentDescriptors Descriptors;
241 int FormatCount = DebugLineData.getU8(OffsetPtr, &Err);
242 bool HasPath = false;
243 for (int I = 0; I != FormatCount && !Err; ++I) {
244 ContentDescriptor Descriptor;
245 Descriptor.Type =
246 dwarf::LineNumberEntryFormat(DebugLineData.getULEB128(OffsetPtr, &Err));
247 Descriptor.Form = dwarf::Form(DebugLineData.getULEB128(OffsetPtr, &Err));
248 if (Descriptor.Type == dwarf::DW_LNCT_path)
249 HasPath = true;
250 if (ContentTypes)
251 ContentTypes->trackContentType(Descriptor.Type);
252 Descriptors.push_back(Descriptor);
253 }
254
255 if (Err)
256 return createStringError(errc::invalid_argument,
257 "failed to parse entry content descriptors: %s",
258 toString(std::move(Err)).c_str());
259
260 if (!HasPath)
261 return createStringError(errc::invalid_argument,
262 "failed to parse entry content descriptions"
263 " because no path was found");
264 return Descriptors;
265}
266
267static Error
268parseV5DirFileTables(const DWARFDataExtractor &DebugLineData,
269 uint64_t *OffsetPtr, const dwarf::FormParams &FormParams,
270 const DWARFContext &Ctx, const DWARFUnit *U,
271 DWARFDebugLine::ContentTypeTracker &ContentTypes,
272 std::vector<DWARFFormValue> &IncludeDirectories,
273 std::vector<DWARFDebugLine::FileNameEntry> &FileNames) {
274 // Get the directory entry description.
275 llvm::Expected<ContentDescriptors> DirDescriptors =
276 parseV5EntryFormat(DebugLineData, OffsetPtr, nullptr);
277 if (!DirDescriptors)
278 return DirDescriptors.takeError();
279
280 // Get the directory entries, according to the format described above.
281 uint64_t DirEntryCount = DebugLineData.getULEB128(OffsetPtr);
282 for (uint64_t I = 0; I != DirEntryCount; ++I) {
283 for (auto Descriptor : *DirDescriptors) {
284 DWARFFormValue Value(Descriptor.Form);
285 switch (Descriptor.Type) {
286 case DW_LNCT_path:
287 if (!Value.extractValue(DebugLineData, OffsetPtr, FormParams, &Ctx, U))
288 return createStringError(errc::invalid_argument,
289 "failed to parse directory entry because "
290 "extracting the form value failed");
291 IncludeDirectories.push_back(Value);
292 break;
293 default:
294 if (!Value.skipValue(DebugLineData, OffsetPtr, FormParams))
295 return createStringError(errc::invalid_argument,
296 "failed to parse directory entry because "
297 "skipping the form value failed");
298 }
299 }
300 }
301
302 // Get the file entry description.
303 llvm::Expected<ContentDescriptors> FileDescriptors =
304 parseV5EntryFormat(DebugLineData, OffsetPtr, &ContentTypes);
305 if (!FileDescriptors)
306 return FileDescriptors.takeError();
307
308 // Get the file entries, according to the format described above.
309 uint64_t FileEntryCount = DebugLineData.getULEB128(OffsetPtr);
310 for (uint64_t I = 0; I != FileEntryCount; ++I) {
311 DWARFDebugLine::FileNameEntry FileEntry;
312 for (auto Descriptor : *FileDescriptors) {
313 DWARFFormValue Value(Descriptor.Form);
314 if (!Value.extractValue(DebugLineData, OffsetPtr, FormParams, &Ctx, U))
315 return createStringError(errc::invalid_argument,
316 "failed to parse file entry because "
317 "extracting the form value failed");
318 switch (Descriptor.Type) {
319 case DW_LNCT_path:
320 FileEntry.Name = Value;
321 break;
322 case DW_LNCT_LLVM_source:
323 FileEntry.Source = Value;
324 break;
325 case DW_LNCT_directory_index:
326 FileEntry.DirIdx = Value.getAsUnsignedConstant().getValue();
327 break;
328 case DW_LNCT_timestamp:
329 FileEntry.ModTime = Value.getAsUnsignedConstant().getValue();
330 break;
331 case DW_LNCT_size:
332 FileEntry.Length = Value.getAsUnsignedConstant().getValue();
333 break;
334 case DW_LNCT_MD5:
335 if (!Value.getAsBlock() || Value.getAsBlock().getValue().size() != 16)
336 return createStringError(
337 errc::invalid_argument,
338 "failed to parse file entry because the MD5 hash is invalid");
339 std::uninitialized_copy_n(Value.getAsBlock().getValue().begin(), 16,
340 FileEntry.Checksum.Bytes.begin());
341 break;
342 default:
343 break;
344 }
345 }
346 FileNames.push_back(FileEntry);
347 }
348 return Error::success();
349}
350
351uint64_t DWARFDebugLine::Prologue::getLength() const {
352 uint64_t Length = PrologueLength + sizeofTotalLength() +
353 sizeof(getVersion()) + sizeofPrologueLength();
354 if (getVersion() >= 5)
355 Length += 2; // Address + Segment selector sizes.
356 return Length;
357}
358
359Error DWARFDebugLine::Prologue::parse(
360 DWARFDataExtractor DebugLineData, uint64_t *OffsetPtr,
361 function_ref<void(Error)> RecoverableErrorHandler, const DWARFContext &Ctx,
362 const DWARFUnit *U) {
363 const uint64_t PrologueOffset = *OffsetPtr;
364
365 clear();
366 DataExtractor::Cursor Cursor(*OffsetPtr);
367 std::tie(TotalLength, FormParams.Format) =
368 DebugLineData.getInitialLength(Cursor);
369
370 DebugLineData =
371 DWARFDataExtractor(DebugLineData, Cursor.tell() + TotalLength);
372 FormParams.Version = DebugLineData.getU16(Cursor);
373 if (Cursor && !versionIsSupported(getVersion())) {
374 // Treat this error as unrecoverable - we cannot be sure what any of
375 // the data represents including the length field, so cannot skip it or make
376 // any reasonable assumptions.
377 *OffsetPtr = Cursor.tell();
378 return createStringError(
379 errc::not_supported,
380 "parsing line table prologue at offset 0x%8.8" PRIx64"llx"
381 ": unsupported version %" PRIu16"u",
382 PrologueOffset, getVersion());
383 }
384
385 if (getVersion() >= 5) {
386 FormParams.AddrSize = DebugLineData.getU8(Cursor);
387 assert((!Cursor || DebugLineData.getAddressSize() == 0 ||((void)0)
388 DebugLineData.getAddressSize() == getAddressSize()) &&((void)0)
389 "Line table header and data extractor disagree")((void)0);
390 SegSelectorSize = DebugLineData.getU8(Cursor);
391 }
392
393 PrologueLength =
394 DebugLineData.getRelocatedValue(Cursor, sizeofPrologueLength());
395 const uint64_t EndPrologueOffset = PrologueLength + Cursor.tell();
396 DebugLineData = DWARFDataExtractor(DebugLineData, EndPrologueOffset);
397 MinInstLength = DebugLineData.getU8(Cursor);
398 if (getVersion() >= 4)
399 MaxOpsPerInst = DebugLineData.getU8(Cursor);
400 DefaultIsStmt = DebugLineData.getU8(Cursor);
401 LineBase = DebugLineData.getU8(Cursor);
402 LineRange = DebugLineData.getU8(Cursor);
403 OpcodeBase = DebugLineData.getU8(Cursor);
404
405 if (Cursor && OpcodeBase == 0) {
406 // If the opcode base is 0, we cannot read the standard opcode lengths (of
407 // which there are supposed to be one fewer than the opcode base). Assume
408 // there are no standard opcodes and continue parsing.
409 RecoverableErrorHandler(createStringError(
410 errc::invalid_argument,
411 "parsing line table prologue at offset 0x%8.8" PRIx64"llx"
412 " found opcode base of 0. Assuming no standard opcodes",
413 PrologueOffset));
414 } else if (Cursor) {
415 StandardOpcodeLengths.reserve(OpcodeBase - 1);
416 for (uint32_t I = 1; I < OpcodeBase; ++I) {
417 uint8_t OpLen = DebugLineData.getU8(Cursor);
418 StandardOpcodeLengths.push_back(OpLen);
419 }
420 }
421
422 *OffsetPtr = Cursor.tell();
423 // A corrupt file name or directory table does not prevent interpretation of
424 // the main line program, so check the cursor state now so that its errors can
425 // be handled separately.
426 if (!Cursor)
427 return createStringError(
428 errc::invalid_argument,
429 "parsing line table prologue at offset 0x%8.8" PRIx64"llx" ": %s",
430 PrologueOffset, toString(Cursor.takeError()).c_str());
431
432 Error E =
433 getVersion() >= 5
434 ? parseV5DirFileTables(DebugLineData, OffsetPtr, FormParams, Ctx, U,
435 ContentTypes, IncludeDirectories, FileNames)
436 : parseV2DirFileTables(DebugLineData, OffsetPtr, ContentTypes,
437 IncludeDirectories, FileNames);
438 if (E) {
439 RecoverableErrorHandler(joinErrors(
440 createStringError(
441 errc::invalid_argument,
442 "parsing line table prologue at 0x%8.8" PRIx64"llx"
443 " found an invalid directory or file table description at"
444 " 0x%8.8" PRIx64"llx",
445 PrologueOffset, *OffsetPtr),
446 std::move(E)));
447 return Error::success();
448 }
449
450 assert(*OffsetPtr <= EndPrologueOffset)((void)0);
451 if (*OffsetPtr != EndPrologueOffset) {
452 RecoverableErrorHandler(createStringError(
453 errc::invalid_argument,
454 "unknown data in line table prologue at offset 0x%8.8" PRIx64"llx"
455 ": parsing ended (at offset 0x%8.8" PRIx64"llx"
456 ") before reaching the prologue end at offset 0x%8.8" PRIx64"llx",
457 PrologueOffset, *OffsetPtr, EndPrologueOffset));
458 }
459 return Error::success();
460}
461
462DWARFDebugLine::Row::Row(bool DefaultIsStmt) { reset(DefaultIsStmt); }
463
464void DWARFDebugLine::Row::postAppend() {
465 Discriminator = 0;
466 BasicBlock = false;
467 PrologueEnd = false;
468 EpilogueBegin = false;
469}
470
471void DWARFDebugLine::Row::reset(bool DefaultIsStmt) {
472 Address.Address = 0;
473 Address.SectionIndex = object::SectionedAddress::UndefSection;
474 Line = 1;
475 Column = 0;
476 File = 1;
477 Isa = 0;
478 Discriminator = 0;
479 IsStmt = DefaultIsStmt;
480 BasicBlock = false;
481 EndSequence = false;
482 PrologueEnd = false;
483 EpilogueBegin = false;
484}
485
486void DWARFDebugLine::Row::dumpTableHeader(raw_ostream &OS, unsigned Indent) {
487 OS.indent(Indent)
488 << "Address Line Column File ISA Discriminator Flags\n";
489 OS.indent(Indent)
490 << "------------------ ------ ------ ------ --- ------------- "
491 "-------------\n";
492}
493
494void DWARFDebugLine::Row::dump(raw_ostream &OS) const {
495 OS << format("0x%16.16" PRIx64"llx" " %6u %6u", Address.Address, Line, Column)
496 << format(" %6u %3u %13u ", File, Isa, Discriminator)
497 << (IsStmt ? " is_stmt" : "") << (BasicBlock ? " basic_block" : "")
498 << (PrologueEnd ? " prologue_end" : "")
499 << (EpilogueBegin ? " epilogue_begin" : "")
500 << (EndSequence ? " end_sequence" : "") << '\n';
501}
502
503DWARFDebugLine::Sequence::Sequence() { reset(); }
504
505void DWARFDebugLine::Sequence::reset() {
506 LowPC = 0;
507 HighPC = 0;
508 SectionIndex = object::SectionedAddress::UndefSection;
509 FirstRowIndex = 0;
510 LastRowIndex = 0;
511 Empty = true;
512}
513
514DWARFDebugLine::LineTable::LineTable() { clear(); }
515
516void DWARFDebugLine::LineTable::dump(raw_ostream &OS,
517 DIDumpOptions DumpOptions) const {
518 Prologue.dump(OS, DumpOptions);
519
520 if (!Rows.empty()) {
521 OS << '\n';
522 Row::dumpTableHeader(OS, 0);
523 for (const Row &R : Rows) {
524 R.dump(OS);
525 }
526 }
527
528 // Terminate the table with a final blank line to clearly delineate it from
529 // later dumps.
530 OS << '\n';
531}
532
533void DWARFDebugLine::LineTable::clear() {
534 Prologue.clear();
535 Rows.clear();
536 Sequences.clear();
537}
538
539DWARFDebugLine::ParsingState::ParsingState(
540 struct LineTable *LT, uint64_t TableOffset,
541 function_ref<void(Error)> ErrorHandler)
542 : LineTable(LT), LineTableOffset(TableOffset), ErrorHandler(ErrorHandler) {
543 resetRowAndSequence();
544}
545
546void DWARFDebugLine::ParsingState::resetRowAndSequence() {
547 Row.reset(LineTable->Prologue.DefaultIsStmt);
548 Sequence.reset();
549}
550
551void DWARFDebugLine::ParsingState::appendRowToMatrix() {
552 unsigned RowNumber = LineTable->Rows.size();
553 if (Sequence.Empty) {
554 // Record the beginning of instruction sequence.
555 Sequence.Empty = false;
556 Sequence.LowPC = Row.Address.Address;
557 Sequence.FirstRowIndex = RowNumber;
558 }
559 LineTable->appendRow(Row);
560 if (Row.EndSequence) {
561 // Record the end of instruction sequence.
562 Sequence.HighPC = Row.Address.Address;
563 Sequence.LastRowIndex = RowNumber + 1;
564 Sequence.SectionIndex = Row.Address.SectionIndex;
565 if (Sequence.isValid())
566 LineTable->appendSequence(Sequence);
567 Sequence.reset();
568 }
569 Row.postAppend();
570}
571
572const DWARFDebugLine::LineTable *
573DWARFDebugLine::getLineTable(uint64_t Offset) const {
574 LineTableConstIter Pos = LineTableMap.find(Offset);
575 if (Pos != LineTableMap.end())
576 return &Pos->second;
577 return nullptr;
578}
579
580Expected<const DWARFDebugLine::LineTable *> DWARFDebugLine::getOrParseLineTable(
581 DWARFDataExtractor &DebugLineData, uint64_t Offset, const DWARFContext &Ctx,
582 const DWARFUnit *U, function_ref<void(Error)> RecoverableErrorHandler) {
583 if (!DebugLineData.isValidOffset(Offset))
584 return createStringError(errc::invalid_argument, "offset 0x%8.8" PRIx64"llx"
585 " is not a valid debug line section offset",
586 Offset);
587
588 std::pair<LineTableIter, bool> Pos =
589 LineTableMap.insert(LineTableMapTy::value_type(Offset, LineTable()));
590 LineTable *LT = &Pos.first->second;
591 if (Pos.second) {
592 if (Error Err =
593 LT->parse(DebugLineData, &Offset, Ctx, U, RecoverableErrorHandler))
594 return std::move(Err);
595 return LT;
596 }
597 return LT;
598}
599
600static StringRef getOpcodeName(uint8_t Opcode, uint8_t OpcodeBase) {
601 assert(Opcode != 0)((void)0);
602 if (Opcode < OpcodeBase)
603 return LNStandardString(Opcode);
604 return "special";
605}
606
607uint64_t DWARFDebugLine::ParsingState::advanceAddr(uint64_t OperationAdvance,
608 uint8_t Opcode,
609 uint64_t OpcodeOffset) {
610 StringRef OpcodeName = getOpcodeName(Opcode, LineTable->Prologue.OpcodeBase);
611 // For versions less than 4, the MaxOpsPerInst member is set to 0, as the
612 // maximum_operations_per_instruction field wasn't introduced until DWARFv4.
613 // Don't warn about bad values in this situation.
614 if (ReportAdvanceAddrProblem && LineTable->Prologue.getVersion() >= 4 &&
615 LineTable->Prologue.MaxOpsPerInst != 1)
616 ErrorHandler(createStringError(
617 errc::not_supported,
618 "line table program at offset 0x%8.8" PRIx64"llx"
619 " contains a %s opcode at offset 0x%8.8" PRIx64"llx"
620 ", but the prologue maximum_operations_per_instruction value is %" PRId8"d"
621 ", which is unsupported. Assuming a value of 1 instead",
622 LineTableOffset, OpcodeName.data(), OpcodeOffset,
623 LineTable->Prologue.MaxOpsPerInst));
624 if (ReportAdvanceAddrProblem && LineTable->Prologue.MinInstLength == 0)
625 ErrorHandler(
626 createStringError(errc::invalid_argument,
627 "line table program at offset 0x%8.8" PRIx64"llx"
628 " contains a %s opcode at offset 0x%8.8" PRIx64"llx"
629 ", but the prologue minimum_instruction_length value "
630 "is 0, which prevents any address advancing",
631 LineTableOffset, OpcodeName.data(), OpcodeOffset));
632 ReportAdvanceAddrProblem = false;
633 uint64_t AddrOffset = OperationAdvance * LineTable->Prologue.MinInstLength;
634 Row.Address.Address += AddrOffset;
635 return AddrOffset;
636}
637
638DWARFDebugLine::ParsingState::AddrAndAdjustedOpcode
639DWARFDebugLine::ParsingState::advanceAddrForOpcode(uint8_t Opcode,
640 uint64_t OpcodeOffset) {
641 assert(Opcode == DW_LNS_const_add_pc ||((void)0)
642 Opcode >= LineTable->Prologue.OpcodeBase)((void)0);
643 if (ReportBadLineRange && LineTable->Prologue.LineRange == 0) {
644 StringRef OpcodeName =
645 getOpcodeName(Opcode, LineTable->Prologue.OpcodeBase);
646 ErrorHandler(
647 createStringError(errc::not_supported,
648 "line table program at offset 0x%8.8" PRIx64"llx"
649 " contains a %s opcode at offset 0x%8.8" PRIx64"llx"
650 ", but the prologue line_range value is 0. The "
651 "address and line will not be adjusted",
652 LineTableOffset, OpcodeName.data(), OpcodeOffset));
653 ReportBadLineRange = false;
654 }
655
656 uint8_t OpcodeValue = Opcode;
657 if (Opcode == DW_LNS_const_add_pc)
658 OpcodeValue = 255;
659 uint8_t AdjustedOpcode = OpcodeValue - LineTable->Prologue.OpcodeBase;
660 uint64_t OperationAdvance =
661 LineTable->Prologue.LineRange != 0
662 ? AdjustedOpcode / LineTable->Prologue.LineRange
663 : 0;
664 uint64_t AddrOffset = advanceAddr(OperationAdvance, Opcode, OpcodeOffset);
665 return {AddrOffset, AdjustedOpcode};
666}
667
668DWARFDebugLine::ParsingState::AddrAndLineDelta
669DWARFDebugLine::ParsingState::handleSpecialOpcode(uint8_t Opcode,
670 uint64_t OpcodeOffset) {
671 // A special opcode value is chosen based on the amount that needs
672 // to be added to the line and address registers. The maximum line
673 // increment for a special opcode is the value of the line_base
674 // field in the header, plus the value of the line_range field,
675 // minus 1 (line base + line range - 1). If the desired line
676 // increment is greater than the maximum line increment, a standard
677 // opcode must be used instead of a special opcode. The "address
678 // advance" is calculated by dividing the desired address increment
679 // by the minimum_instruction_length field from the header. The
680 // special opcode is then calculated using the following formula:
681 //
682 // opcode = (desired line increment - line_base) +
683 // (line_range * address advance) + opcode_base
684 //
685 // If the resulting opcode is greater than 255, a standard opcode
686 // must be used instead.
687 //
688 // To decode a special opcode, subtract the opcode_base from the
689 // opcode itself to give the adjusted opcode. The amount to
690 // increment the address register is the result of the adjusted
691 // opcode divided by the line_range multiplied by the
692 // minimum_instruction_length field from the header. That is:
693 //
694 // address increment = (adjusted opcode / line_range) *
695 // minimum_instruction_length
696 //
697 // The amount to increment the line register is the line_base plus
698 // the result of the adjusted opcode modulo the line_range. That is:
699 //
700 // line increment = line_base + (adjusted opcode % line_range)
701
702 DWARFDebugLine::ParsingState::AddrAndAdjustedOpcode AddrAdvanceResult =
703 advanceAddrForOpcode(Opcode, OpcodeOffset);
704 int32_t LineOffset = 0;
705 if (LineTable->Prologue.LineRange != 0)
706 LineOffset =
707 LineTable->Prologue.LineBase +
708 (AddrAdvanceResult.AdjustedOpcode % LineTable->Prologue.LineRange);
709 Row.Line += LineOffset;
710 return {AddrAdvanceResult.AddrDelta, LineOffset};
711}
712
713/// Parse a ULEB128 using the specified \p Cursor. \returns the parsed value on
714/// success, or None if \p Cursor is in a failing state.
715template <typename T>
716static Optional<T> parseULEB128(DWARFDataExtractor &Data,
717 DataExtractor::Cursor &Cursor) {
718 T Value = Data.getULEB128(Cursor);
719 if (Cursor)
720 return Value;
721 return None;
722}
723
724Error DWARFDebugLine::LineTable::parse(
725 DWARFDataExtractor &DebugLineData, uint64_t *OffsetPtr,
726 const DWARFContext &Ctx, const DWARFUnit *U,
727 function_ref<void(Error)> RecoverableErrorHandler, raw_ostream *OS,
728 bool Verbose) {
729 assert((OS || !Verbose) && "cannot have verbose output without stream")((void)0);
730 const uint64_t DebugLineOffset = *OffsetPtr;
731
732 clear();
733
734 Error PrologueErr =
735 Prologue.parse(DebugLineData, OffsetPtr, RecoverableErrorHandler, Ctx, U);
736
737 if (OS) {
1
Assuming 'OS' is null
→
2
←
Taking false branch
→
738 DIDumpOptions DumpOptions;
739 DumpOptions.Verbose = Verbose;
740 Prologue.dump(*OS, DumpOptions);
741 }
742
743 if (PrologueErr) {
3
←
Calling 'Error::operator bool'
→
6
←
Returning from 'Error::operator bool'
→
7
←
Taking false branch
→
744 // Ensure there is a blank line after the prologue to clearly delineate it
745 // from later dumps.
746 if (OS)
747 *OS << "\n";
748 return PrologueErr;
749 }
750
751 uint64_t ProgramLength = Prologue.TotalLength + Prologue.sizeofTotalLength();
752 if (!DebugLineData.isValidOffsetForDataOfSize(DebugLineOffset,
8
←
Taking true branch
→
753 ProgramLength)) {
754 assert(DebugLineData.size() > DebugLineOffset &&((void)0)
755 "prologue parsing should handle invalid offset")((void)0);
756 uint64_t BytesRemaining = DebugLineData.size() - DebugLineOffset;
757 RecoverableErrorHandler(
758 createStringError(errc::invalid_argument,
759 "line table program with offset 0x%8.8" PRIx64"llx"
760 " has length 0x%8.8" PRIx64"llx" " but only 0x%8.8" PRIx64"llx"
761 " bytes are available",
762 DebugLineOffset, ProgramLength, BytesRemaining));
763 // Continue by capping the length at the number of remaining bytes.
764 ProgramLength = BytesRemaining;
765 }
766
767 // Create a DataExtractor which can only see the data up to the end of the
768 // table, to prevent reading past the end.
769 const uint64_t EndOffset = DebugLineOffset + ProgramLength;
770 DWARFDataExtractor TableData(DebugLineData, EndOffset);
771
772 // See if we should tell the data extractor the address size.
773 if (TableData.getAddressSize() == 0)
9
←
Assuming the condition is false
→
10
←
Taking false branch
→
774 TableData.setAddressSize(Prologue.getAddressSize());
775 else
776 assert(Prologue.getAddressSize() == 0 ||((void)0)
777 Prologue.getAddressSize() == TableData.getAddressSize())((void)0);
778
779 ParsingState State(this, DebugLineOffset, RecoverableErrorHandler);
780
781 *OffsetPtr = DebugLineOffset + Prologue.getLength();
782 if (OS
10.1
'OS' is null
10.1
'OS' is null
 && *OffsetPtr < EndOffset) {
783 *OS << '\n';
784 Row::dumpTableHeader(*OS, /*Indent=*/Verbose ? 12 : 0);
785 }
786 bool TombstonedAddress = false;
787 auto EmitRow = [&] {
788 if (!TombstonedAddress) {
789 if (Verbose) {
790 *OS << "\n";
791 OS->indent(12);
792 }
793 if (OS)
794 State.Row.dump(*OS);
795 State.appendRowToMatrix();
796 }
797 };
798 while (*OffsetPtr < EndOffset) {
11
←
Assuming the condition is true
→
12
←
Loop condition is true. Entering loop body
→
799 DataExtractor::Cursor Cursor(*OffsetPtr);
800
801 if (Verbose)
13
←
Assuming 'Verbose' is true
→
14
←
Taking true branch
→
802 *OS << format("0x%08.08" PRIx64"llx" ": ", *OffsetPtr);
15
←
Called C++ object pointer is null
803
804 uint64_t OpcodeOffset = *OffsetPtr;
805 uint8_t Opcode = TableData.getU8(Cursor);
806 size_t RowCount = Rows.size();
807
808 if (Cursor && Verbose)
809 *OS << format("%02.02" PRIx8"x" " ", Opcode);
810
811 if (Opcode == 0) {
812 // Extended Opcodes always start with a zero opcode followed by
813 // a uleb128 length so you can skip ones you don't know about
814 uint64_t Len = TableData.getULEB128(Cursor);
815 uint64_t ExtOffset = Cursor.tell();
816
817 // Tolerate zero-length; assume length is correct and soldier on.
818 if (Len == 0) {
819 if (Cursor && Verbose)
820 *OS << "Badly formed extended line op (length 0)\n";
821 if (!Cursor) {
822 if (Verbose)
823 *OS << "\n";
824 RecoverableErrorHandler(Cursor.takeError());
825 }
826 *OffsetPtr = Cursor.tell();
827 continue;
828 }
829
830 uint8_t SubOpcode = TableData.getU8(Cursor);
831 // OperandOffset will be the same as ExtOffset, if it was not possible to
832 // read the SubOpcode.
833 uint64_t OperandOffset = Cursor.tell();
834 if (Verbose)
835 *OS << LNExtendedString(SubOpcode);
836 switch (SubOpcode) {
837 case DW_LNE_end_sequence:
838 // Set the end_sequence register of the state machine to true and
839 // append a row to the matrix using the current values of the
840 // state-machine registers. Then reset the registers to the initial
841 // values specified above. Every statement program sequence must end
842 // with a DW_LNE_end_sequence instruction which creates a row whose
843 // address is that of the byte after the last target machine instruction
844 // of the sequence.
845 State.Row.EndSequence = true;
846 // No need to test the Cursor is valid here, since it must be to get
847 // into this code path - if it were invalid, the default case would be
848 // followed.
849 EmitRow();
850 State.resetRowAndSequence();
851 break;
852
853 case DW_LNE_set_address:
854 // Takes a single relocatable address as an operand. The size of the
855 // operand is the size appropriate to hold an address on the target
856 // machine. Set the address register to the value given by the
857 // relocatable address. All of the other statement program opcodes
858 // that affect the address register add a delta to it. This instruction
859 // stores a relocatable value into it instead.
860 //
861 // Make sure the extractor knows the address size. If not, infer it
862 // from the size of the operand.
863 {
864 uint8_t ExtractorAddressSize = TableData.getAddressSize();
865 uint64_t OpcodeAddressSize = Len - 1;
866 if (ExtractorAddressSize != OpcodeAddressSize &&
867 ExtractorAddressSize != 0)
868 RecoverableErrorHandler(createStringError(
869 errc::invalid_argument,
870 "mismatching address size at offset 0x%8.8" PRIx64"llx"
871 " expected 0x%2.2" PRIx8"x" " found 0x%2.2" PRIx64"llx",
872 ExtOffset, ExtractorAddressSize, Len - 1));
873
874 // Assume that the line table is correct and temporarily override the
875 // address size. If the size is unsupported, give up trying to read
876 // the address and continue to the next opcode.
877 if (OpcodeAddressSize != 1 && OpcodeAddressSize != 2 &&
878 OpcodeAddressSize != 4 && OpcodeAddressSize != 8) {
879 RecoverableErrorHandler(createStringError(
880 errc::invalid_argument,
881 "address size 0x%2.2" PRIx64"llx"
882 " of DW_LNE_set_address opcode at offset 0x%8.8" PRIx64"llx"
883 " is unsupported",
884 OpcodeAddressSize, ExtOffset));
885 TableData.skip(Cursor, OpcodeAddressSize);
886 } else {
887 TableData.setAddressSize(OpcodeAddressSize);
888 State.Row.Address.Address = TableData.getRelocatedAddress(
889 Cursor, &State.Row.Address.SectionIndex);
890
891 uint64_t Tombstone =
892 dwarf::computeTombstoneAddress(OpcodeAddressSize);
893 TombstonedAddress = State.Row.Address.Address == Tombstone;
894
895 // Restore the address size if the extractor already had it.
896 if (ExtractorAddressSize != 0)
897 TableData.setAddressSize(ExtractorAddressSize);
898 }
899
900 if (Cursor && Verbose) {
901 *OS << " (";
902 DWARFFormValue::dumpAddress(*OS, OpcodeAddressSize, State.Row.Address.Address);
903 *OS << ')';
904 }
905 }
906 break;
907
908 case DW_LNE_define_file:
909 // Takes 4 arguments. The first is a null terminated string containing
910 // a source file name. The second is an unsigned LEB128 number
911 // representing the directory index of the directory in which the file
912 // was found. The third is an unsigned LEB128 number representing the
913 // time of last modification of the file. The fourth is an unsigned
914 // LEB128 number representing the length in bytes of the file. The time
915 // and length fields may contain LEB128(0) if the information is not
916 // available.
917 //
918 // The directory index represents an entry in the include_directories
919 // section of the statement program prologue. The index is LEB128(0)
920 // if the file was found in the current directory of the compilation,
921 // LEB128(1) if it was found in the first directory in the
922 // include_directories section, and so on. The directory index is
923 // ignored for file names that represent full path names.
924 //
925 // The files are numbered, starting at 1, in the order in which they
926 // appear; the names in the prologue come before names defined by
927 // the DW_LNE_define_file instruction. These numbers are used in the
928 // the file register of the state machine.
929 {
930 FileNameEntry FileEntry;
931 const char *Name = TableData.getCStr(Cursor);
932 FileEntry.Name =
933 DWARFFormValue::createFromPValue(dwarf::DW_FORM_string, Name);
934 FileEntry.DirIdx = TableData.getULEB128(Cursor);
935 FileEntry.ModTime = TableData.getULEB128(Cursor);
936 FileEntry.Length = TableData.getULEB128(Cursor);
937 Prologue.FileNames.push_back(FileEntry);
938 if (Cursor && Verbose)
939 *OS << " (" << Name << ", dir=" << FileEntry.DirIdx << ", mod_time="
940 << format("(0x%16.16" PRIx64"llx" ")", FileEntry.ModTime)
941 << ", length=" << FileEntry.Length << ")";
942 }
943 break;
944
945 case DW_LNE_set_discriminator:
946 State.Row.Discriminator = TableData.getULEB128(Cursor);
947 if (Cursor && Verbose)
948 *OS << " (" << State.Row.Discriminator << ")";
949 break;
950
951 default:
952 if (Cursor && Verbose)
953 *OS << format("Unrecognized extended op 0x%02.02" PRIx8"x", SubOpcode)
954 << format(" length %" PRIx64"llx", Len);
955 // Len doesn't include the zero opcode byte or the length itself, but
956 // it does include the sub_opcode, so we have to adjust for that.
957 TableData.skip(Cursor, Len - 1);
958 break;
959 }
960 // Make sure the length as recorded in the table and the standard length
961 // for the opcode match. If they don't, continue from the end as claimed
962 // by the table. Similarly, continue from the claimed end in the event of
963 // a parsing error.
964 uint64_t End = ExtOffset + Len;
965 if (Cursor && Cursor.tell() != End)
966 RecoverableErrorHandler(createStringError(
967 errc::illegal_byte_sequence,
968 "unexpected line op length at offset 0x%8.8" PRIx64"llx"
969 " expected 0x%2.2" PRIx64"llx" " found 0x%2.2" PRIx64"llx",
970 ExtOffset, Len, Cursor.tell() - ExtOffset));
971 if (!Cursor && Verbose) {
972 DWARFDataExtractor::Cursor ByteCursor(OperandOffset);
973 uint8_t Byte = TableData.getU8(ByteCursor);
974 if (ByteCursor) {
975 *OS << " (<parsing error>";
976 do {
977 *OS << format(" %2.2" PRIx8"x", Byte);
978 Byte = TableData.getU8(ByteCursor);
979 } while (ByteCursor);
980 *OS << ")";
981 }
982
983 // The only parse failure in this case should be if the end was reached.
984 // In that case, throw away the error, as the main Cursor's error will
985 // be sufficient.
986 consumeError(ByteCursor.takeError());
987 }
988 *OffsetPtr = End;
989 } else if (Opcode < Prologue.OpcodeBase) {
990 if (Verbose)
991 *OS << LNStandardString(Opcode);
992 switch (Opcode) {
993 // Standard Opcodes
994 case DW_LNS_copy:
995 // Takes no arguments. Append a row to the matrix using the
996 // current values of the state-machine registers.
997 EmitRow();
998 break;
999
1000 case DW_LNS_advance_pc:
1001 // Takes a single unsigned LEB128 operand, multiplies it by the
1002 // min_inst_length field of the prologue, and adds the
1003 // result to the address register of the state machine.
1004 if (Optional<uint64_t> Operand =
1005 parseULEB128<uint64_t>(TableData, Cursor)) {
1006 uint64_t AddrOffset =
1007 State.advanceAddr(*Operand, Opcode, OpcodeOffset);
1008 if (Verbose)
1009 *OS << " (" << AddrOffset << ")";
1010 }
1011 break;
1012
1013 case DW_LNS_advance_line:
1014 // Takes a single signed LEB128 operand and adds that value to
1015 // the line register of the state machine.
1016 {
1017 int64_t LineDelta = TableData.getSLEB128(Cursor);
1018 if (Cursor) {
1019 State.Row.Line += LineDelta;
1020 if (Verbose)
1021 *OS << " (" << State.Row.Line << ")";
1022 }
1023 }
1024 break;
1025
1026 case DW_LNS_set_file:
1027 // Takes a single unsigned LEB128 operand and stores it in the file
1028 // register of the state machine.
1029 if (Optional<uint16_t> File =
1030 parseULEB128<uint16_t>(TableData, Cursor)) {
1031 State.Row.File = *File;
1032 if (Verbose)
1033 *OS << " (" << State.Row.File << ")";
1034 }
1035 break;
1036
1037 case DW_LNS_set_column:
1038 // Takes a single unsigned LEB128 operand and stores it in the
1039 // column register of the state machine.
1040 if (Optional<uint16_t> Column =
1041 parseULEB128<uint16_t>(TableData, Cursor)) {
1042 State.Row.Column = *Column;
1043 if (Verbose)
1044 *OS << " (" << State.Row.Column << ")";
1045 }
1046 break;
1047
1048 case DW_LNS_negate_stmt:
1049 // Takes no arguments. Set the is_stmt register of the state
1050 // machine to the logical negation of its current value.
1051 State.Row.IsStmt = !State.Row.IsStmt;
1052 break;
1053
1054 case DW_LNS_set_basic_block:
1055 // Takes no arguments. Set the basic_block register of the
1056 // state machine to true
1057 State.Row.BasicBlock = true;
1058 break;
1059
1060 case DW_LNS_const_add_pc:
1061 // Takes no arguments. Add to the address register of the state
1062 // machine the address increment value corresponding to special
1063 // opcode 255. The motivation for DW_LNS_const_add_pc is this:
1064 // when the statement program needs to advance the address by a
1065 // small amount, it can use a single special opcode, which occupies
1066 // a single byte. When it needs to advance the address by up to
1067 // twice the range of the last special opcode, it can use
1068 // DW_LNS_const_add_pc followed by a special opcode, for a total
1069 // of two bytes. Only if it needs to advance the address by more
1070 // than twice that range will it need to use both DW_LNS_advance_pc
1071 // and a special opcode, requiring three or more bytes.
1072 {
1073 uint64_t AddrOffset =
1074 State.advanceAddrForOpcode(Opcode, OpcodeOffset).AddrDelta;
1075 if (Verbose)
1076 *OS << format(" (0x%16.16" PRIx64"llx" ")", AddrOffset);
1077 }
1078 break;
1079
1080 case DW_LNS_fixed_advance_pc:
1081 // Takes a single uhalf operand. Add to the address register of
1082 // the state machine the value of the (unencoded) operand. This
1083 // is the only extended opcode that takes an argument that is not
1084 // a variable length number. The motivation for DW_LNS_fixed_advance_pc
1085 // is this: existing assemblers cannot emit DW_LNS_advance_pc or
1086 // special opcodes because they cannot encode LEB128 numbers or
1087 // judge when the computation of a special opcode overflows and
1088 // requires the use of DW_LNS_advance_pc. Such assemblers, however,
1089 // can use DW_LNS_fixed_advance_pc instead, sacrificing compression.
1090 {
1091 uint16_t PCOffset =
1092 TableData.getRelocatedValue(Cursor, 2);
1093 if (Cursor) {
1094 State.Row.Address.Address += PCOffset;
1095 if (Verbose)
1096 *OS << format(" (0x%4.4" PRIx16"x" ")", PCOffset);
1097 }
1098 }
1099 break;
1100
1101 case DW_LNS_set_prologue_end:
1102 // Takes no arguments. Set the prologue_end register of the
1103 // state machine to true
1104 State.Row.PrologueEnd = true;
1105 break;
1106
1107 case DW_LNS_set_epilogue_begin:
1108 // Takes no arguments. Set the basic_block register of the
1109 // state machine to true
1110 State.Row.EpilogueBegin = true;
1111 break;
1112
1113 case DW_LNS_set_isa:
1114 // Takes a single unsigned LEB128 operand and stores it in the
1115 // ISA register of the state machine.
1116 if (Optional<uint8_t> Isa = parseULEB128<uint8_t>(TableData, Cursor)) {
1117 State.Row.Isa = *Isa;
1118 if (Verbose)
1119 *OS << " (" << (uint64_t)State.Row.Isa << ")";
1120 }
1121 break;
1122
1123 default:
1124 // Handle any unknown standard opcodes here. We know the lengths
1125 // of such opcodes because they are specified in the prologue
1126 // as a multiple of LEB128 operands for each opcode.
1127 {
1128 assert(Opcode - 1U < Prologue.StandardOpcodeLengths.size())((void)0);
1129 if (Verbose)
1130 *OS << "Unrecognized standard opcode";
1131 uint8_t OpcodeLength = Prologue.StandardOpcodeLengths[Opcode - 1];
1132 std::vector<uint64_t> Operands;
1133 for (uint8_t I = 0; I < OpcodeLength; ++I) {
1134 if (Optional<uint64_t> Value =
1135 parseULEB128<uint64_t>(TableData, Cursor))
1136 Operands.push_back(*Value);
1137 else
1138 break;
1139 }
1140 if (Verbose && !Operands.empty()) {
1141 *OS << " (operands: ";
1142 bool First = true;
1143 for (uint64_t Value : Operands) {
1144 if (!First)
1145 *OS << ", ";
1146 First = false;
1147 *OS << format("0x%16.16" PRIx64"llx", Value);
1148 }
1149 if (Verbose)
1150 *OS << ')';
1151 }
1152 }
1153 break;
1154 }
1155
1156 *OffsetPtr = Cursor.tell();
1157 } else {
1158 // Special Opcodes.
1159 ParsingState::AddrAndLineDelta Delta =
1160 State.handleSpecialOpcode(Opcode, OpcodeOffset);
1161
1162 if (Verbose)
1163 *OS << "address += " << Delta.Address << ", line += " << Delta.Line;
1164 EmitRow();
1165 *OffsetPtr = Cursor.tell();
1166 }
1167
1168 // When a row is added to the matrix, it is also dumped, which includes a
1169 // new line already, so don't add an extra one.
1170 if (Verbose && Rows.size() == RowCount)
1171 *OS << "\n";
1172
1173 // Most parse failures other than when parsing extended opcodes are due to
1174 // failures to read ULEBs. Bail out of parsing, since we don't know where to
1175 // continue reading from as there is no stated length for such byte
1176 // sequences. Print the final trailing new line if needed before doing so.
1177 if (!Cursor && Opcode != 0) {
1178 if (Verbose)
1179 *OS << "\n";
1180 return Cursor.takeError();
1181 }
1182
1183 if (!Cursor)
1184 RecoverableErrorHandler(Cursor.takeError());
1185 }
1186
1187 if (!State.Sequence.Empty)
1188 RecoverableErrorHandler(createStringError(
1189 errc::illegal_byte_sequence,
1190 "last sequence in debug line table at offset 0x%8.8" PRIx64"llx"
1191 " is not terminated",
1192 DebugLineOffset));
1193
1194 // Sort all sequences so that address lookup will work faster.
1195 if (!Sequences.empty()) {
1196 llvm::sort(Sequences, Sequence::orderByHighPC);
1197 // Note: actually, instruction address ranges of sequences should not
1198 // overlap (in shared objects and executables). If they do, the address
1199 // lookup would still work, though, but result would be ambiguous.
1200 // We don't report warning in this case. For example,
1201 // sometimes .so compiled from multiple object files contains a few
1202 // rudimentary sequences for address ranges [0x0, 0xsomething).
1203 }
1204
1205 // Terminate the table with a final blank line to clearly delineate it from
1206 // later dumps.
1207 if (OS)
1208 *OS << "\n";
1209
1210 return Error::success();
1211}
1212
1213uint32_t DWARFDebugLine::LineTable::findRowInSeq(
1214 const DWARFDebugLine::Sequence &Seq,
1215 object::SectionedAddress Address) const {
1216 if (!Seq.containsPC(Address))
1217 return UnknownRowIndex;
1218 assert(Seq.SectionIndex == Address.SectionIndex)((void)0);
1219 // In some cases, e.g. first instruction in a function, the compiler generates
1220 // two entries, both with the same address. We want the last one.
1221 //
1222 // In general we want a non-empty range: the last row whose address is less
1223 // than or equal to Address. This can be computed as upper_bound - 1.
1224 DWARFDebugLine::Row Row;
1225 Row.Address = Address;
1226 RowIter FirstRow = Rows.begin() + Seq.FirstRowIndex;
1227 RowIter LastRow = Rows.begin() + Seq.LastRowIndex;
1228 assert(FirstRow->Address.Address <= Row.Address.Address &&((void)0)
1229 Row.Address.Address < LastRow[-1].Address.Address)((void)0);
1230 RowIter RowPos = std::upper_bound(FirstRow + 1, LastRow - 1, Row,
1231 DWARFDebugLine::Row::orderByAddress) -
1232 1;
1233 assert(Seq.SectionIndex == RowPos->Address.SectionIndex)((void)0);
1234 return RowPos - Rows.begin();
1235}
1236
1237uint32_t DWARFDebugLine::LineTable::lookupAddress(
1238 object::SectionedAddress Address) const {
1239
1240 // Search for relocatable addresses
1241 uint32_t Result = lookupAddressImpl(Address);
1242
1243 if (Result != UnknownRowIndex ||
1244 Address.SectionIndex == object::SectionedAddress::UndefSection)
1245 return Result;
1246
1247 // Search for absolute addresses
1248 Address.SectionIndex = object::SectionedAddress::UndefSection;
1249 return lookupAddressImpl(Address);
1250}
1251
1252uint32_t DWARFDebugLine::LineTable::lookupAddressImpl(
1253 object::SectionedAddress Address) const {
1254 // First, find an instruction sequence containing the given address.
1255 DWARFDebugLine::Sequence Sequence;
1256 Sequence.SectionIndex = Address.SectionIndex;
1257 Sequence.HighPC = Address.Address;
1258 SequenceIter It = llvm::upper_bound(Sequences, Sequence,
1259 DWARFDebugLine::Sequence::orderByHighPC);
1260 if (It == Sequences.end() || It->SectionIndex != Address.SectionIndex)
1261 return UnknownRowIndex;
1262 return findRowInSeq(*It, Address);
1263}
1264
1265bool DWARFDebugLine::LineTable::lookupAddressRange(
1266 object::SectionedAddress Address, uint64_t Size,
1267 std::vector<uint32_t> &Result) const {
1268
1269 // Search for relocatable addresses
1270 if (lookupAddressRangeImpl(Address, Size, Result))
1271 return true;
1272
1273 if (Address.SectionIndex == object::SectionedAddress::UndefSection)
1274 return false;
1275
1276 // Search for absolute addresses
1277 Address.SectionIndex = object::SectionedAddress::UndefSection;
1278 return lookupAddressRangeImpl(Address, Size, Result);
1279}
1280
1281bool DWARFDebugLine::LineTable::lookupAddressRangeImpl(
1282 object::SectionedAddress Address, uint64_t Size,
1283 std::vector<uint32_t> &Result) const {
1284 if (Sequences.empty())
1285 return false;
1286 uint64_t EndAddr = Address.Address + Size;
1287 // First, find an instruction sequence containing the given address.
1288 DWARFDebugLine::Sequence Sequence;
1289 Sequence.SectionIndex = Address.SectionIndex;
1290 Sequence.HighPC = Address.Address;
1291 SequenceIter LastSeq = Sequences.end();
1292 SequenceIter SeqPos = llvm::upper_bound(
1293 Sequences, Sequence, DWARFDebugLine::Sequence::orderByHighPC);
1294 if (SeqPos == LastSeq || !SeqPos->containsPC(Address))
1295 return false;
1296
1297 SequenceIter StartPos = SeqPos;
1298
1299 // Add the rows from the first sequence to the vector, starting with the
1300 // index we just calculated
1301
1302 while (SeqPos != LastSeq && SeqPos->LowPC < EndAddr) {
1303 const DWARFDebugLine::Sequence &CurSeq = *SeqPos;
1304 // For the first sequence, we need to find which row in the sequence is the
1305 // first in our range.
1306 uint32_t FirstRowIndex = CurSeq.FirstRowIndex;
1307 if (SeqPos == StartPos)
1308 FirstRowIndex = findRowInSeq(CurSeq, Address);
1309
1310 // Figure out the last row in the range.
1311 uint32_t LastRowIndex =
1312 findRowInSeq(CurSeq, {EndAddr - 1, Address.SectionIndex});
1313 if (LastRowIndex == UnknownRowIndex)
1314 LastRowIndex = CurSeq.LastRowIndex - 1;
1315
1316 assert(FirstRowIndex != UnknownRowIndex)((void)0);
1317 assert(LastRowIndex != UnknownRowIndex)((void)0);
1318
1319 for (uint32_t I = FirstRowIndex; I <= LastRowIndex; ++I) {
1320 Result.push_back(I);
1321 }
1322
1323 ++SeqPos;
1324 }
1325
1326 return true;
1327}
1328
1329Optional<StringRef> DWARFDebugLine::LineTable::getSourceByIndex(uint64_t FileIndex,
1330 FileLineInfoKind Kind) const {
1331 if (Kind == FileLineInfoKind::None || !Prologue.hasFileAtIndex(FileIndex))
1332 return None;
1333 const FileNameEntry &Entry = Prologue.getFileNameEntry(FileIndex);
1334 if (Optional<const char *> source = Entry.Source.getAsCString())
1335 return StringRef(*source);
1336 return None;
1337}
1338
1339static bool isPathAbsoluteOnWindowsOrPosix(const Twine &Path) {
1340 // Debug info can contain paths from any OS, not necessarily
1341 // an OS we're currently running on. Moreover different compilation units can
1342 // be compiled on different operating systems and linked together later.
1343 return sys::path::is_absolute(Path, sys::path::Style::posix) ||
1344 sys::path::is_absolute(Path, sys::path::Style::windows);
1345}
1346
1347bool DWARFDebugLine::Prologue::getFileNameByIndex(
1348 uint64_t FileIndex, StringRef CompDir, FileLineInfoKind Kind,
1349 std::string &Result, sys::path::Style Style) const {
1350 if (Kind == FileLineInfoKind::None || !hasFileAtIndex(FileIndex))
1351 return false;
1352 const FileNameEntry &Entry = getFileNameEntry(FileIndex);
1353 Optional<const char *> Name = Entry.Name.getAsCString();
1354 if (!Name)
1355 return false;
1356 StringRef FileName = *Name;
1357 if (Kind == FileLineInfoKind::RawValue ||
1358 isPathAbsoluteOnWindowsOrPosix(FileName)) {
1359 Result = std::string(FileName);
1360 return true;
1361 }
1362 if (Kind == FileLineInfoKind::BaseNameOnly) {
1363 Result = std::string(llvm::sys::path::filename(FileName));
1364 return true;
1365 }
1366
1367 SmallString<16> FilePath;
1368 StringRef IncludeDir;
1369 // Be defensive about the contents of Entry.
1370 if (getVersion() >= 5) {
1371 // DirIdx 0 is the compilation directory, so don't include it for
1372 // relative names.
1373 if ((Entry.DirIdx != 0 || Kind != FileLineInfoKind::RelativeFilePath) &&
1374 Entry.DirIdx < IncludeDirectories.size())
1375 IncludeDir = IncludeDirectories[Entry.DirIdx].getAsCString().getValue();
1376 } else {
1377 if (0 < Entry.DirIdx && Entry.DirIdx <= IncludeDirectories.size())
1378 IncludeDir =
1379 IncludeDirectories[Entry.DirIdx - 1].getAsCString().getValue();
1380 }
1381
1382 // For absolute paths only, include the compilation directory of compile unit.
1383 // We know that FileName is not absolute, the only way to have an absolute
1384 // path at this point would be if IncludeDir is absolute.
1385 if (Kind == FileLineInfoKind::AbsoluteFilePath && !CompDir.empty() &&
1386 !isPathAbsoluteOnWindowsOrPosix(IncludeDir))
1387 sys::path::append(FilePath, Style, CompDir);
1388
1389 assert((Kind == FileLineInfoKind::AbsoluteFilePath ||((void)0)
1390 Kind == FileLineInfoKind::RelativeFilePath) &&((void)0)
1391 "invalid FileLineInfo Kind")((void)0);
1392
1393 // sys::path::append skips empty strings.
1394 sys::path::append(FilePath, Style, IncludeDir, FileName);
1395 Result = std::string(FilePath.str());
1396 return true;
1397}
1398
1399bool DWARFDebugLine::LineTable::getFileLineInfoForAddress(
1400 object::SectionedAddress Address, const char *CompDir,
1401 FileLineInfoKind Kind, DILineInfo &Result) const {
1402 // Get the index of row we're looking for in the line table.
1403 uint32_t RowIndex = lookupAddress(Address);
1404 if (RowIndex == -1U)
1405 return false;
1406 // Take file number and line/column from the row.
1407 const auto &Row = Rows[RowIndex];
1408 if (!getFileNameByIndex(Row.File, CompDir, Kind, Result.FileName))
1409 return false;
1410 Result.Line = Row.Line;
1411 Result.Column = Row.Column;
1412 Result.Discriminator = Row.Discriminator;
1413 Result.Source = getSourceByIndex(Row.File, Kind);
1414 return true;
1415}
1416
1417// We want to supply the Unit associated with a .debug_line[.dwo] table when
1418// we dump it, if possible, but still dump the table even if there isn't a Unit.
1419// Therefore, collect up handles on all the Units that point into the
1420// line-table section.
1421static DWARFDebugLine::SectionParser::LineToUnitMap
1422buildLineToUnitMap(DWARFUnitVector::iterator_range Units) {
1423 DWARFDebugLine::SectionParser::LineToUnitMap LineToUnit;
1424 for (const auto &U : Units)
1425 if (auto CUDIE = U->getUnitDIE())
1426 if (auto StmtOffset = toSectionOffset(CUDIE.find(DW_AT_stmt_list)))
1427 LineToUnit.insert(std::make_pair(*StmtOffset, &*U));
1428 return LineToUnit;
1429}
1430
1431DWARFDebugLine::SectionParser::SectionParser(
1432 DWARFDataExtractor &Data, const DWARFContext &C,
1433 DWARFUnitVector::iterator_range Units)
1434 : DebugLineData(Data), Context(C) {
1435 LineToUnit = buildLineToUnitMap(Units);
1436 if (!DebugLineData.isValidOffset(Offset))
1437 Done = true;
1438}
1439
1440bool DWARFDebugLine::Prologue::totalLengthIsValid() const {
1441 return TotalLength != 0u;
1442}
1443
1444DWARFDebugLine::LineTable DWARFDebugLine::SectionParser::parseNext(
1445 function_ref<void(Error)> RecoverableErrorHandler,
1446 function_ref<void(Error)> UnrecoverableErrorHandler, raw_ostream *OS,
1447 bool Verbose) {
1448 assert(DebugLineData.isValidOffset(Offset) &&((void)0)
1449 "parsing should have terminated")((void)0);
1450 DWARFUnit *U = prepareToParse(Offset);
1451 uint64_t OldOffset = Offset;
1452 LineTable LT;
1453 if (Error Err = LT.parse(DebugLineData, &Offset, Context, U,
1454 RecoverableErrorHandler, OS, Verbose))
1455 UnrecoverableErrorHandler(std::move(Err));
1456 moveToNextTable(OldOffset, LT.Prologue);
1457 return LT;
1458}
1459
1460void DWARFDebugLine::SectionParser::skip(
1461 function_ref<void(Error)> RecoverableErrorHandler,
1462 function_ref<void(Error)> UnrecoverableErrorHandler) {
1463 assert(DebugLineData.isValidOffset(Offset) &&((void)0)
1464 "parsing should have terminated")((void)0);
1465 DWARFUnit *U = prepareToParse(Offset);
1466 uint64_t OldOffset = Offset;
1467 LineTable LT;
1468 if (Error Err = LT.Prologue.parse(DebugLineData, &Offset,
1469 RecoverableErrorHandler, Context, U))
1470 UnrecoverableErrorHandler(std::move(Err));
1471 moveToNextTable(OldOffset, LT.Prologue);
1472}
1473
1474DWARFUnit *DWARFDebugLine::SectionParser::prepareToParse(uint64_t Offset) {
1475 DWARFUnit *U = nullptr;
1476 auto It = LineToUnit.find(Offset);
1477 if (It != LineToUnit.end())
1478 U = It->second;
1479 DebugLineData.setAddressSize(U ? U->getAddressByteSize() : 0);
1480 return U;
1481}
1482
1483void DWARFDebugLine::SectionParser::moveToNextTable(uint64_t OldOffset,
1484 const Prologue &P) {
1485 // If the length field is not valid, we don't know where the next table is, so
1486 // cannot continue to parse. Mark the parser as done, and leave the Offset
1487 // value as it currently is. This will be the end of the bad length field.
1488 if (!P.totalLengthIsValid()) {
1489 Done = true;
1490 return;
1491 }
1492
1493 Offset = OldOffset + P.TotalLength + P.sizeofTotalLength();
1494 if (!DebugLineData.isValidOffset(Offset)) {
1495 Done = true;
1496 }
1497}
←

/usr/src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Support/Error.h

1//===- llvm/Support/Error.h - Recoverable error handling --------*- 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 an API used to report recoverable errors.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_SUPPORT_ERROR_H
14#define LLVM_SUPPORT_ERROR_H
15
16#include "llvm-c/Error.h"
17#include "llvm/ADT/STLExtras.h"
18#include "llvm/ADT/SmallVector.h"
19#include "llvm/ADT/StringExtras.h"
20#include "llvm/ADT/Twine.h"
21#include "llvm/Config/abi-breaking.h"
22#include "llvm/Support/AlignOf.h"
23#include "llvm/Support/Compiler.h"
24#include "llvm/Support/Debug.h"
25#include "llvm/Support/ErrorHandling.h"
26#include "llvm/Support/ErrorOr.h"
27#include "llvm/Support/Format.h"
28#include "llvm/Support/raw_ostream.h"
29#include <algorithm>
30#include <cassert>
31#include <cstdint>
32#include <cstdlib>
33#include <functional>
34#include <memory>
35#include <new>
36#include <string>
37#include <system_error>
38#include <type_traits>
39#include <utility>
40#include <vector>
41
42namespace llvm {
43
44class ErrorSuccess;
45
46/// Base class for error info classes. Do not extend this directly: Extend
47/// the ErrorInfo template subclass instead.
48class ErrorInfoBase {
49public:
50 virtual ~ErrorInfoBase() = default;
51
52 /// Print an error message to an output stream.
53 virtual void log(raw_ostream &OS) const = 0;
54
55 /// Return the error message as a string.
56 virtual std::string message() const {
57 std::string Msg;
58 raw_string_ostream OS(Msg);
59 log(OS);
60 return OS.str();
61 }
62
63 /// Convert this error to a std::error_code.
64 ///
65 /// This is a temporary crutch to enable interaction with code still
66 /// using std::error_code. It will be removed in the future.
67 virtual std::error_code convertToErrorCode() const = 0;
68
69 // Returns the class ID for this type.
70 static const void *classID() { return &ID; }
71
72 // Returns the class ID for the dynamic type of this ErrorInfoBase instance.
73 virtual const void *dynamicClassID() const = 0;
74
75 // Check whether this instance is a subclass of the class identified by
76 // ClassID.
77 virtual bool isA(const void *const ClassID) const {
78 return ClassID == classID();
79 }
80
81 // Check whether this instance is a subclass of ErrorInfoT.
82 template <typename ErrorInfoT> bool isA() const {
83 return isA(ErrorInfoT::classID());
84 }
85
86private:
87 virtual void anchor();
88
89 static char ID;
90};
91
92/// Lightweight error class with error context and mandatory checking.
93///
94/// Instances of this class wrap a ErrorInfoBase pointer. Failure states
95/// are represented by setting the pointer to a ErrorInfoBase subclass
96/// instance containing information describing the failure. Success is
97/// represented by a null pointer value.
98///
99/// Instances of Error also contains a 'Checked' flag, which must be set
100/// before the destructor is called, otherwise the destructor will trigger a
101/// runtime error. This enforces at runtime the requirement that all Error
102/// instances be checked or returned to the caller.
103///
104/// There are two ways to set the checked flag, depending on what state the
105/// Error instance is in. For Error instances indicating success, it
106/// is sufficient to invoke the boolean conversion operator. E.g.:
107///
108/// @code{.cpp}
109/// Error foo(<...>);
110///
111/// if (auto E = foo(<...>))
112/// return E; // <- Return E if it is in the error state.
113/// // We have verified that E was in the success state. It can now be safely
114/// // destroyed.
115/// @endcode
116///
117/// A success value *can not* be dropped. For example, just calling 'foo(<...>)'
118/// without testing the return value will raise a runtime error, even if foo
119/// returns success.
120///
121/// For Error instances representing failure, you must use either the
122/// handleErrors or handleAllErrors function with a typed handler. E.g.:
123///
124/// @code{.cpp}
125/// class MyErrorInfo : public ErrorInfo<MyErrorInfo> {
126/// // Custom error info.
127/// };
128///
129/// Error foo(<...>) { return make_error<MyErrorInfo>(...); }
130///
131/// auto E = foo(<...>); // <- foo returns failure with MyErrorInfo.
132/// auto NewE =
133/// handleErrors(E,
134/// [](const MyErrorInfo &M) {
135/// // Deal with the error.
136/// },
137/// [](std::unique_ptr<OtherError> M) -> Error {
138/// if (canHandle(*M)) {
139/// // handle error.
140/// return Error::success();
141/// }
142/// // Couldn't handle this error instance. Pass it up the stack.
143/// return Error(std::move(M));
144/// );
145/// // Note - we must check or return NewE in case any of the handlers
146/// // returned a new error.
147/// @endcode
148///
149/// The handleAllErrors function is identical to handleErrors, except
150/// that it has a void return type, and requires all errors to be handled and
151/// no new errors be returned. It prevents errors (assuming they can all be
152/// handled) from having to be bubbled all the way to the top-level.
153///
154/// *All* Error instances must be checked before destruction, even if
155/// they're moved-assigned or constructed from Success values that have already
156/// been checked. This enforces checking through all levels of the call stack.
157class LLVM_NODISCARD[[clang::warn_unused_result]] Error {
158 // ErrorList needs to be able to yank ErrorInfoBase pointers out of Errors
159 // to add to the error list. It can't rely on handleErrors for this, since
160 // handleErrors does not support ErrorList handlers.
161 friend class ErrorList;
162
163 // handleErrors needs to be able to set the Checked flag.
164 template <typename... HandlerTs>
165 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
166
167 // Expected<T> needs to be able to steal the payload when constructed from an
168 // error.
169 template <typename T> friend class Expected;
170
171 // wrap needs to be able to steal the payload.
172 friend LLVMErrorRef wrap(Error);
173
174protected:
175 /// Create a success value. Prefer using 'Error::success()' for readability
176 Error() {
177 setPtr(nullptr);
178 setChecked(false);
179 }
180
181public:
182 /// Create a success value.
183 static ErrorSuccess success();
184
185 // Errors are not copy-constructable.
186 Error(const Error &Other) = delete;
187
188 /// Move-construct an error value. The newly constructed error is considered
189 /// unchecked, even if the source error had been checked. The original error
190 /// becomes a checked Success value, regardless of its original state.
191 Error(Error &&Other) {
192 setChecked(true);
193 *this = std::move(Other);
194 }
195
196 /// Create an error value. Prefer using the 'make_error' function, but
197 /// this constructor can be useful when "re-throwing" errors from handlers.
198 Error(std::unique_ptr<ErrorInfoBase> Payload) {
199 setPtr(Payload.release());
200 setChecked(false);
201 }
202
203 // Errors are not copy-assignable.
204 Error &operator=(const Error &Other) = delete;
205
206 /// Move-assign an error value. The current error must represent success, you
207 /// you cannot overwrite an unhandled error. The current error is then
208 /// considered unchecked. The source error becomes a checked success value,
209 /// regardless of its original state.
210 Error &operator=(Error &&Other) {
211 // Don't allow overwriting of unchecked values.
212 assertIsChecked();
213 setPtr(Other.getPtr());
214
215 // This Error is unchecked, even if the source error was checked.
216 setChecked(false);
217
218 // Null out Other's payload and set its checked bit.
219 Other.setPtr(nullptr);
220 Other.setChecked(true);
221
222 return *this;
223 }
224
225 /// Destroy a Error. Fails with a call to abort() if the error is
226 /// unchecked.
227 ~Error() {
228 assertIsChecked();
229 delete getPtr();
230 }
231
232 /// Bool conversion. Returns true if this Error is in a failure state,
233 /// and false if it is in an accept state. If the error is in a Success state
234 /// it will be considered checked.
235 explicit operator bool() {
236 setChecked(getPtr() == nullptr);
4
←
Assuming the condition is true
→
237 return getPtr() != nullptr;
5
←
Returning zero, which participates in a condition later
→
238 }
239
240 /// Check whether one error is a subclass of another.
241 template <typename ErrT> bool isA() const {
242 return getPtr() && getPtr()->isA(ErrT::classID());
243 }
244
245 /// Returns the dynamic class id of this error, or null if this is a success
246 /// value.
247 const void* dynamicClassID() const {
248 if (!getPtr())
249 return nullptr;
250 return getPtr()->dynamicClassID();
251 }
252
253private:
254#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
255 // assertIsChecked() happens very frequently, but under normal circumstances
256 // is supposed to be a no-op. So we want it to be inlined, but having a bunch
257 // of debug prints can cause the function to be too large for inlining. So
258 // it's important that we define this function out of line so that it can't be
259 // inlined.
260 LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn))
261 void fatalUncheckedError() const;
262#endif
263
264 void assertIsChecked() {
265#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
266 if (LLVM_UNLIKELY(!getChecked() || getPtr())__builtin_expect((bool)(!getChecked() || getPtr()), false))
267 fatalUncheckedError();
268#endif
269 }
270
271 ErrorInfoBase *getPtr() const {
272#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
273 return reinterpret_cast<ErrorInfoBase*>(
274 reinterpret_cast<uintptr_t>(Payload) &
275 ~static_cast<uintptr_t>(0x1));
276#else
277 return Payload;
278#endif
279 }
280
281 void setPtr(ErrorInfoBase *EI) {
282#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
283 Payload = reinterpret_cast<ErrorInfoBase*>(
284 (reinterpret_cast<uintptr_t>(EI) &
285 ~static_cast<uintptr_t>(0x1)) |
286 (reinterpret_cast<uintptr_t>(Payload) & 0x1));
287#else
288 Payload = EI;
289#endif
290 }
291
292 bool getChecked() const {
293#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
294 return (reinterpret_cast<uintptr_t>(Payload) & 0x1) == 0;
295#else
296 return true;
297#endif
298 }
299
300 void setChecked(bool V) {
301#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
302 Payload = reinterpret_cast<ErrorInfoBase*>(
303 (reinterpret_cast<uintptr_t>(Payload) &
304 ~static_cast<uintptr_t>(0x1)) |
305 (V ? 0 : 1));
306#endif
307 }
308
309 std::unique_ptr<ErrorInfoBase> takePayload() {
310 std::unique_ptr<ErrorInfoBase> Tmp(getPtr());
311 setPtr(nullptr);
312 setChecked(true);
313 return Tmp;
314 }
315
316 friend raw_ostream &operator<<(raw_ostream &OS, const Error &E) {
317 if (auto P = E.getPtr())
318 P->log(OS);
319 else
320 OS << "success";
321 return OS;
322 }
323
324 ErrorInfoBase *Payload = nullptr;
325};
326
327/// Subclass of Error for the sole purpose of identifying the success path in
328/// the type system. This allows to catch invalid conversion to Expected<T> at
329/// compile time.
330class ErrorSuccess final : public Error {};
331
332inline ErrorSuccess Error::success() { return ErrorSuccess(); }
333
334/// Make a Error instance representing failure using the given error info
335/// type.
336template <typename ErrT, typename... ArgTs> Error make_error(ArgTs &&... Args) {
337 return Error(std::make_unique<ErrT>(std::forward<ArgTs>(Args)...));
338}
339
340/// Base class for user error types. Users should declare their error types
341/// like:
342///
343/// class MyError : public ErrorInfo<MyError> {
344/// ....
345/// };
346///
347/// This class provides an implementation of the ErrorInfoBase::kind
348/// method, which is used by the Error RTTI system.
349template <typename ThisErrT, typename ParentErrT = ErrorInfoBase>
350class ErrorInfo : public ParentErrT {
351public:
352 using ParentErrT::ParentErrT; // inherit constructors
353
354 static const void *classID() { return &ThisErrT::ID; }
355
356 const void *dynamicClassID() const override { return &ThisErrT::ID; }
357
358 bool isA(const void *const ClassID) const override {
359 return ClassID == classID() || ParentErrT::isA(ClassID);
360 }
361};
362
363/// Special ErrorInfo subclass representing a list of ErrorInfos.
364/// Instances of this class are constructed by joinError.
365class ErrorList final : public ErrorInfo<ErrorList> {
366 // handleErrors needs to be able to iterate the payload list of an
367 // ErrorList.
368 template <typename... HandlerTs>
369 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
370
371 // joinErrors is implemented in terms of join.
372 friend Error joinErrors(Error, Error);
373
374public:
375 void log(raw_ostream &OS) const override {
376 OS << "Multiple errors:\n";
377 for (auto &ErrPayload : Payloads) {
378 ErrPayload->log(OS);
379 OS << "\n";
380 }
381 }
382
383 std::error_code convertToErrorCode() const override;
384
385 // Used by ErrorInfo::classID.
386 static char ID;
387
388private:
389 ErrorList(std::unique_ptr<ErrorInfoBase> Payload1,
390 std::unique_ptr<ErrorInfoBase> Payload2) {
391 assert(!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() &&((void)0)
392 "ErrorList constructor payloads should be singleton errors")((void)0);
393 Payloads.push_back(std::move(Payload1));
394 Payloads.push_back(std::move(Payload2));
395 }
396
397 static Error join(Error E1, Error E2) {
398 if (!E1)
399 return E2;
400 if (!E2)
401 return E1;
402 if (E1.isA<ErrorList>()) {
403 auto &E1List = static_cast<ErrorList &>(*E1.getPtr());
404 if (E2.isA<ErrorList>()) {
405 auto E2Payload = E2.takePayload();
406 auto &E2List = static_cast<ErrorList &>(*E2Payload);
407 for (auto &Payload : E2List.Payloads)
408 E1List.Payloads.push_back(std::move(Payload));
409 } else
410 E1List.Payloads.push_back(E2.takePayload());
411
412 return E1;
413 }
414 if (E2.isA<ErrorList>()) {
415 auto &E2List = static_cast<ErrorList &>(*E2.getPtr());
416 E2List.Payloads.insert(E2List.Payloads.begin(), E1.takePayload());
417 return E2;
418 }
419 return Error(std::unique_ptr<ErrorList>(
420 new ErrorList(E1.takePayload(), E2.takePayload())));
421 }
422
423 std::vector<std::unique_ptr<ErrorInfoBase>> Payloads;
424};
425
426/// Concatenate errors. The resulting Error is unchecked, and contains the
427/// ErrorInfo(s), if any, contained in E1, followed by the
428/// ErrorInfo(s), if any, contained in E2.
429inline Error joinErrors(Error E1, Error E2) {
430 return ErrorList::join(std::move(E1), std::move(E2));
431}
432
433/// Tagged union holding either a T or a Error.
434///
435/// This class parallels ErrorOr, but replaces error_code with Error. Since
436/// Error cannot be copied, this class replaces getError() with
437/// takeError(). It also adds an bool errorIsA<ErrT>() method for testing the
438/// error class type.
439///
440/// Example usage of 'Expected<T>' as a function return type:
441///
442/// @code{.cpp}
443/// Expected<int> myDivide(int A, int B) {
444/// if (B == 0) {
445/// // return an Error
446/// return createStringError(inconvertibleErrorCode(),
447/// "B must not be zero!");
448/// }
449/// // return an integer
450/// return A / B;
451/// }
452/// @endcode
453///
454/// Checking the results of to a function returning 'Expected<T>':
455/// @code{.cpp}
456/// if (auto E = Result.takeError()) {
457/// // We must consume the error. Typically one of:
458/// // - return the error to our caller
459/// // - toString(), when logging
460/// // - consumeError(), to silently swallow the error
461/// // - handleErrors(), to distinguish error types
462/// errs() << "Problem with division " << toString(std::move(E)) << "\n";
463/// return;
464/// }
465/// // use the result
466/// outs() << "The answer is " << *Result << "\n";
467/// @endcode
468///
469/// For unit-testing a function returning an 'Expceted<T>', see the
470/// 'EXPECT_THAT_EXPECTED' macros in llvm/Testing/Support/Error.h
471
472template <class T> class LLVM_NODISCARD[[clang::warn_unused_result]] Expected {
473 template <class T1> friend class ExpectedAsOutParameter;
474 template <class OtherT> friend class Expected;
475
476 static constexpr bool isRef = std::is_reference<T>::value;
477
478 using wrap = std::reference_wrapper<std::remove_reference_t<T>>;
479
480 using error_type = std::unique_ptr<ErrorInfoBase>;
481
482public:
483 using storage_type = std::conditional_t<isRef, wrap, T>;
484 using value_type = T;
485
486private:
487 using reference = std::remove_reference_t<T> &;
488 using const_reference = const std::remove_reference_t<T> &;
489 using pointer = std::remove_reference_t<T> *;
490 using const_pointer = const std::remove_reference_t<T> *;
491
492public:
493 /// Create an Expected<T> error value from the given Error.
494 Expected(Error Err)
495 : HasError(true)
496#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
497 // Expected is unchecked upon construction in Debug builds.
498 , Unchecked(true)
499#endif
500 {
501 assert(Err && "Cannot create Expected<T> from Error success value.")((void)0);
502 new (getErrorStorage()) error_type(Err.takePayload());
503 }
504
505 /// Forbid to convert from Error::success() implicitly, this avoids having
506 /// Expected<T> foo() { return Error::success(); } which compiles otherwise
507 /// but triggers the assertion above.
508 Expected(ErrorSuccess) = delete;
509
510 /// Create an Expected<T> success value from the given OtherT value, which
511 /// must be convertible to T.
512 template <typename OtherT>
513 Expected(OtherT &&Val,
514 std::enable_if_t<std::is_convertible<OtherT, T>::value> * = nullptr)
515 : HasError(false)
516#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
517 // Expected is unchecked upon construction in Debug builds.
518 ,
519 Unchecked(true)
520#endif
521 {
522 new (getStorage()) storage_type(std::forward<OtherT>(Val));
523 }
524
525 /// Move construct an Expected<T> value.
526 Expected(Expected &&Other) { moveConstruct(std::move(Other)); }
527
528 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
529 /// must be convertible to T.
530 template <class OtherT>
531 Expected(
532 Expected<OtherT> &&Other,
533 std::enable_if_t<std::is_convertible<OtherT, T>::value> * = nullptr) {
534 moveConstruct(std::move(Other));
535 }
536
537 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
538 /// isn't convertible to T.
539 template <class OtherT>
540 explicit Expected(
541 Expected<OtherT> &&Other,
542 std::enable_if_t<!std::is_convertible<OtherT, T>::value> * = nullptr) {
543 moveConstruct(std::move(Other));
544 }
545
546 /// Move-assign from another Expected<T>.
547 Expected &operator=(Expected &&Other) {
548 moveAssign(std::move(Other));
549 return *this;
550 }
551
552 /// Destroy an Expected<T>.
553 ~Expected() {
554 assertIsChecked();
555 if (!HasError)
556 getStorage()->~storage_type();
557 else
558 getErrorStorage()->~error_type();
559 }
560
561 /// Return false if there is an error.
562 explicit operator bool() {
563#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
564 Unchecked = HasError;
565#endif
566 return !HasError;
567 }
568
569 /// Returns a reference to the stored T value.
570 reference get() {
571 assertIsChecked();
572 return *getStorage();
573 }
574
575 /// Returns a const reference to the stored T value.
576 const_reference get() const {
577 assertIsChecked();
578 return const_cast<Expected<T> *>(this)->get();
579 }
580
581 /// Check that this Expected<T> is an error of type ErrT.
582 template <typename ErrT> bool errorIsA() const {
583 return HasError && (*getErrorStorage())->template isA<ErrT>();
584 }
585
586 /// Take ownership of the stored error.
587 /// After calling this the Expected<T> is in an indeterminate state that can
588 /// only be safely destructed. No further calls (beside the destructor) should
589 /// be made on the Expected<T> value.
590 Error takeError() {
591#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
592 Unchecked = false;
593#endif
594 return HasError ? Error(std::move(*getErrorStorage())) : Error::success();
595 }
596
597 /// Returns a pointer to the stored T value.
598 pointer operator->() {
599 assertIsChecked();
600 return toPointer(getStorage());
601 }
602
603 /// Returns a const pointer to the stored T value.
604 const_pointer operator->() const {
605 assertIsChecked();
606 return toPointer(getStorage());
607 }
608
609 /// Returns a reference to the stored T value.
610 reference operator*() {
611 assertIsChecked();
612 return *getStorage();
613 }
614
615 /// Returns a const reference to the stored T value.
616 const_reference operator*() const {
617 assertIsChecked();
618 return *getStorage();
619 }
620
621private:
622 template <class T1>
623 static bool compareThisIfSameType(const T1 &a, const T1 &b) {
624 return &a == &b;
625 }
626
627 template <class T1, class T2>
628 static bool compareThisIfSameType(const T1 &, const T2 &) {
629 return false;
630 }
631
632 template <class OtherT> void moveConstruct(Expected<OtherT> &&Other) {
633 HasError = Other.HasError;
634#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
635 Unchecked = true;
636 Other.Unchecked = false;
637#endif
638
639 if (!HasError)
640 new (getStorage()) storage_type(std::move(*Other.getStorage()));
641 else
642 new (getErrorStorage()) error_type(std::move(*Other.getErrorStorage()));
643 }
644
645 template <class OtherT> void moveAssign(Expected<OtherT> &&Other) {
646 assertIsChecked();
647
648 if (compareThisIfSameType(*this, Other))
649 return;
650
651 this->~Expected();
652 new (this) Expected(std::move(Other));
653 }
654
655 pointer toPointer(pointer Val) { return Val; }
656
657 const_pointer toPointer(const_pointer Val) const { return Val; }
658
659 pointer toPointer(wrap *Val) { return &Val->get(); }
660
661 const_pointer toPointer(const wrap *Val) const { return &Val->get(); }
662
663 storage_type *getStorage() {
664 assert(!HasError && "Cannot get value when an error exists!")((void)0);
665 return reinterpret_cast<storage_type *>(&TStorage);
666 }
667
668 const storage_type *getStorage() const {
669 assert(!HasError && "Cannot get value when an error exists!")((void)0);
670 return reinterpret_cast<const storage_type *>(&TStorage);
671 }
672
673 error_type *getErrorStorage() {
674 assert(HasError && "Cannot get error when a value exists!")((void)0);
675 return reinterpret_cast<error_type *>(&ErrorStorage);
676 }
677
678 const error_type *getErrorStorage() const {
679 assert(HasError && "Cannot get error when a value exists!")((void)0);
680 return reinterpret_cast<const error_type *>(&ErrorStorage);
681 }
682
683 // Used by ExpectedAsOutParameter to reset the checked flag.
684 void setUnchecked() {
685#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
686 Unchecked = true;
687#endif
688 }
689
690#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
691 LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn))
692 LLVM_ATTRIBUTE_NOINLINE__attribute__((noinline))
693 void fatalUncheckedExpected() const {
694 dbgs() << "Expected<T> must be checked before access or destruction.\n";
695 if (HasError) {
696 dbgs() << "Unchecked Expected<T> contained error:\n";
697 (*getErrorStorage())->log(dbgs());
698 } else
699 dbgs() << "Expected<T> value was in success state. (Note: Expected<T> "
700 "values in success mode must still be checked prior to being "
701 "destroyed).\n";
702 abort();
703 }
704#endif
705
706 void assertIsChecked() const {
707#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
708 if (LLVM_UNLIKELY(Unchecked)__builtin_expect((bool)(Unchecked), false))
709 fatalUncheckedExpected();
710#endif
711 }
712
713 union {
714 AlignedCharArrayUnion<storage_type> TStorage;
715 AlignedCharArrayUnion<error_type> ErrorStorage;
716 };
717 bool HasError : 1;
718#if LLVM_ENABLE_ABI_BREAKING_CHECKS0
719 bool Unchecked : 1;
720#endif
721};
722
723/// Report a serious error, calling any installed error handler. See
724/// ErrorHandling.h.
725LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn)) void report_fatal_error(Error Err,
726 bool gen_crash_diag = true);
727
728/// Report a fatal error if Err is a failure value.
729///
730/// This function can be used to wrap calls to fallible functions ONLY when it
731/// is known that the Error will always be a success value. E.g.
732///
733/// @code{.cpp}
734/// // foo only attempts the fallible operation if DoFallibleOperation is
735/// // true. If DoFallibleOperation is false then foo always returns
736/// // Error::success().
737/// Error foo(bool DoFallibleOperation);
738///
739/// cantFail(foo(false));
740/// @endcode
741inline void cantFail(Error Err, const char *Msg = nullptr) {
742 if (Err) {
743 if (!Msg)
744 Msg = "Failure value returned from cantFail wrapped call";
745#ifndef NDEBUG1
746 std::string Str;
747 raw_string_ostream OS(Str);
748 OS << Msg << "\n" << Err;
749 Msg = OS.str().c_str();
750#endif
751 llvm_unreachable(Msg)__builtin_unreachable();
752 }
753}
754
755/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
756/// returns the contained value.
757///
758/// This function can be used to wrap calls to fallible functions ONLY when it
759/// is known that the Error will always be a success value. E.g.
760///
761/// @code{.cpp}
762/// // foo only attempts the fallible operation if DoFallibleOperation is
763/// // true. If DoFallibleOperation is false then foo always returns an int.
764/// Expected<int> foo(bool DoFallibleOperation);
765///
766/// int X = cantFail(foo(false));
767/// @endcode
768template <typename T>
769T cantFail(Expected<T> ValOrErr, const char *Msg = nullptr) {
770 if (ValOrErr)
771 return std::move(*ValOrErr);
772 else {
773 if (!Msg)
774 Msg = "Failure value returned from cantFail wrapped call";
775#ifndef NDEBUG1
776 std::string Str;
777 raw_string_ostream OS(Str);
778 auto E = ValOrErr.takeError();
779 OS << Msg << "\n" << E;
780 Msg = OS.str().c_str();
781#endif
782 llvm_unreachable(Msg)__builtin_unreachable();
783 }
784}
785
786/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
787/// returns the contained reference.
788///
789/// This function can be used to wrap calls to fallible functions ONLY when it
790/// is known that the Error will always be a success value. E.g.
791///
792/// @code{.cpp}
793/// // foo only attempts the fallible operation if DoFallibleOperation is
794/// // true. If DoFallibleOperation is false then foo always returns a Bar&.
795/// Expected<Bar&> foo(bool DoFallibleOperation);
796///
797/// Bar &X = cantFail(foo(false));
798/// @endcode
799template <typename T>
800T& cantFail(Expected<T&> ValOrErr, const char *Msg = nullptr) {
801 if (ValOrErr)
802 return *ValOrErr;
803 else {
804 if (!Msg)
805 Msg = "Failure value returned from cantFail wrapped call";
806#ifndef NDEBUG1
807 std::string Str;
808 raw_string_ostream OS(Str);
809 auto E = ValOrErr.takeError();
810 OS << Msg << "\n" << E;
811 Msg = OS.str().c_str();
812#endif
813 llvm_unreachable(Msg)__builtin_unreachable();
814 }
815}
816
817/// Helper for testing applicability of, and applying, handlers for
818/// ErrorInfo types.
819template <typename HandlerT>
820class ErrorHandlerTraits
821 : public ErrorHandlerTraits<decltype(
822 &std::remove_reference<HandlerT>::type::operator())> {};
823
824// Specialization functions of the form 'Error (const ErrT&)'.
825template <typename ErrT> class ErrorHandlerTraits<Error (&)(ErrT &)> {
826public:
827 static bool appliesTo(const ErrorInfoBase &E) {
828 return E.template isA<ErrT>();
829 }
830
831 template <typename HandlerT>
832 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
833 assert(appliesTo(*E) && "Applying incorrect handler")((void)0);
834 return H(static_cast<ErrT &>(*E));
835 }
836};
837
838// Specialization functions of the form 'void (const ErrT&)'.
839template <typename ErrT> class ErrorHandlerTraits<void (&)(ErrT &)> {
840public:
841 static bool appliesTo(const ErrorInfoBase &E) {
842 return E.template isA<ErrT>();
843 }
844
845 template <typename HandlerT>
846 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
847 assert(appliesTo(*E) && "Applying incorrect handler")((void)0);
848 H(static_cast<ErrT &>(*E));
849 return Error::success();
850 }
851};
852
853/// Specialization for functions of the form 'Error (std::unique_ptr<ErrT>)'.
854template <typename ErrT>
855class ErrorHandlerTraits<Error (&)(std::unique_ptr<ErrT>)> {
856public:
857 static bool appliesTo(const ErrorInfoBase &E) {
858 return E.template isA<ErrT>();
859 }
860
861 template <typename HandlerT>
862 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
863 assert(appliesTo(*E) && "Applying incorrect handler")((void)0);
864 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
865 return H(std::move(SubE));
866 }
867};
868
869/// Specialization for functions of the form 'void (std::unique_ptr<ErrT>)'.
870template <typename ErrT>
871class ErrorHandlerTraits<void (&)(std::unique_ptr<ErrT>)> {
872public:
873 static bool appliesTo(const ErrorInfoBase &E) {
874 return E.template isA<ErrT>();
875 }
876
877 template <typename HandlerT>
878 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
879 assert(appliesTo(*E) && "Applying incorrect handler")((void)0);
880 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
881 H(std::move(SubE));
882 return Error::success();
883 }
884};
885
886// Specialization for member functions of the form 'RetT (const ErrT&)'.
887template <typename C, typename RetT, typename ErrT>
888class ErrorHandlerTraits<RetT (C::*)(ErrT &)>
889 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
890
891// Specialization for member functions of the form 'RetT (const ErrT&) const'.
892template <typename C, typename RetT, typename ErrT>
893class ErrorHandlerTraits<RetT (C::*)(ErrT &) const>
894 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
895
896// Specialization for member functions of the form 'RetT (const ErrT&)'.
897template <typename C, typename RetT, typename ErrT>
898class ErrorHandlerTraits<RetT (C::*)(const ErrT &)>
899 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
900
901// Specialization for member functions of the form 'RetT (const ErrT&) const'.
902template <typename C, typename RetT, typename ErrT>
903class ErrorHandlerTraits<RetT (C::*)(const ErrT &) const>
904 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
905
906/// Specialization for member functions of the form
907/// 'RetT (std::unique_ptr<ErrT>)'.
908template <typename C, typename RetT, typename ErrT>
909class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>)>
910 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
911
912/// Specialization for member functions of the form
913/// 'RetT (std::unique_ptr<ErrT>) const'.
914template <typename C, typename RetT, typename ErrT>
915class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>) const>
916 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
917
918inline Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload) {
919 return Error(std::move(Payload));
920}
921
922template <typename HandlerT, typename... HandlerTs>
923Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload,
924 HandlerT &&Handler, HandlerTs &&... Handlers) {
925 if (ErrorHandlerTraits<HandlerT>::appliesTo(*Payload))
926 return ErrorHandlerTraits<HandlerT>::apply(std::forward<HandlerT>(Handler),
927 std::move(Payload));
928 return handleErrorImpl(std::move(Payload),
929 std::forward<HandlerTs>(Handlers)...);
930}
931
932/// Pass the ErrorInfo(s) contained in E to their respective handlers. Any
933/// unhandled errors (or Errors returned by handlers) are re-concatenated and
934/// returned.
935/// Because this function returns an error, its result must also be checked
936/// or returned. If you intend to handle all errors use handleAllErrors
937/// (which returns void, and will abort() on unhandled errors) instead.
938template <typename... HandlerTs>
939Error handleErrors(Error E, HandlerTs &&... Hs) {
940 if (!E)
941 return Error::success();
942
943 std::unique_ptr<ErrorInfoBase> Payload = E.takePayload();
944
945 if (Payload->isA<ErrorList>()) {
946 ErrorList &List = static_cast<ErrorList &>(*Payload);
947 Error R;
948 for (auto &P : List.Payloads)
949 R = ErrorList::join(
950 std::move(R),
951 handleErrorImpl(std::move(P), std::forward<HandlerTs>(Hs)...));
952 return R;
953 }
954
955 return handleErrorImpl(std::move(Payload), std::forward<HandlerTs>(Hs)...);
956}
957
958/// Behaves the same as handleErrors, except that by contract all errors
959/// *must* be handled by the given handlers (i.e. there must be no remaining
960/// errors after running the handlers, or llvm_unreachable is called).
961template <typename... HandlerTs>
962void handleAllErrors(Error E, HandlerTs &&... Handlers) {
963 cantFail(handleErrors(std::move(E), std::forward<HandlerTs>(Handlers)...));
964}
965
966/// Check that E is a non-error, then drop it.
967/// If E is an error, llvm_unreachable will be called.
968inline void handleAllErrors(Error E) {
969 cantFail(std::move(E));
970}
971
972/// Handle any errors (if present) in an Expected<T>, then try a recovery path.
973///
974/// If the incoming value is a success value it is returned unmodified. If it
975/// is a failure value then it the contained error is passed to handleErrors.
976/// If handleErrors is able to handle the error then the RecoveryPath functor
977/// is called to supply the final result. If handleErrors is not able to
978/// handle all errors then the unhandled errors are returned.
979///
980/// This utility enables the follow pattern:
981///
982/// @code{.cpp}
983/// enum FooStrategy { Aggressive, Conservative };
984/// Expected<Foo> foo(FooStrategy S);
985///
986/// auto ResultOrErr =
987/// handleExpected(
988/// foo(Aggressive),
989/// []() { return foo(Conservative); },
990/// [](AggressiveStrategyError&) {
991/// // Implicitly conusme this - we'll recover by using a conservative
992/// // strategy.
993/// });
994///
995/// @endcode
996template <typename T, typename RecoveryFtor, typename... HandlerTs>
997Expected<T> handleExpected(Expected<T> ValOrErr, RecoveryFtor &&RecoveryPath,
998 HandlerTs &&... Handlers) {
999 if (ValOrErr)
1000 return ValOrErr;
1001
1002 if (auto Err = handleErrors(ValOrErr.takeError(),
1003 std::forward<HandlerTs>(Handlers)...))
1004 return std::move(Err);
1005
1006 return RecoveryPath();
1007}
1008
1009/// Log all errors (if any) in E to OS. If there are any errors, ErrorBanner
1010/// will be printed before the first one is logged. A newline will be printed
1011/// after each error.
1012///
1013/// This function is compatible with the helpers from Support/WithColor.h. You
1014/// can pass any of them as the OS. Please consider using them instead of
1015/// including 'error: ' in the ErrorBanner.
1016///
1017/// This is useful in the base level of your program to allow clean termination
1018/// (allowing clean deallocation of resources, etc.), while reporting error
1019/// information to the user.
1020void logAllUnhandledErrors(Error E, raw_ostream &OS, Twine ErrorBanner = {});
1021
1022/// Write all error messages (if any) in E to a string. The newline character
1023/// is used to separate error messages.
1024inline std::string toString(Error E) {
1025 SmallVector<std::string, 2> Errors;
1026 handleAllErrors(std::move(E), [&Errors](const ErrorInfoBase &EI) {
1027 Errors.push_back(EI.message());
1028 });
1029 return join(Errors.begin(), Errors.end(), "\n");
1030}
1031
1032/// Consume a Error without doing anything. This method should be used
1033/// only where an error can be considered a reasonable and expected return
1034/// value.
1035///
1036/// Uses of this method are potentially indicative of design problems: If it's
1037/// legitimate to do nothing while processing an "error", the error-producer
1038/// might be more clearly refactored to return an Optional<T>.
1039inline void consumeError(Error Err) {
1040 handleAllErrors(std::move(Err), [](const ErrorInfoBase &) {});
1041}
1042
1043/// Convert an Expected to an Optional without doing anything. This method
1044/// should be used only where an error can be considered a reasonable and
1045/// expected return value.
1046///
1047/// Uses of this method are potentially indicative of problems: perhaps the
1048/// error should be propagated further, or the error-producer should just
1049/// return an Optional in the first place.
1050template <typename T> Optional<T> expectedToOptional(Expected<T> &&E) {
1051 if (E)
1052 return std::move(*E);
1053 consumeError(E.takeError());
1054 return None;
1055}
1056
1057/// Helper for converting an Error to a bool.
1058///
1059/// This method returns true if Err is in an error state, or false if it is
1060/// in a success state. Puts Err in a checked state in both cases (unlike
1061/// Error::operator bool(), which only does this for success states).
1062inline bool errorToBool(Error Err) {
1063 bool IsError = static_cast<bool>(Err);
1064 if (IsError)
1065 consumeError(std::move(Err));
1066 return IsError;
1067}
1068
1069/// Helper for Errors used as out-parameters.
1070///
1071/// This helper is for use with the Error-as-out-parameter idiom, where an error
1072/// is passed to a function or method by reference, rather than being returned.
1073/// In such cases it is helpful to set the checked bit on entry to the function
1074/// so that the error can be written to (unchecked Errors abort on assignment)
1075/// and clear the checked bit on exit so that clients cannot accidentally forget
1076/// to check the result. This helper performs these actions automatically using
1077/// RAII:
1078///
1079/// @code{.cpp}
1080/// Result foo(Error &Err) {
1081/// ErrorAsOutParameter ErrAsOutParam(&Err); // 'Checked' flag set
1082/// // <body of foo>
1083/// // <- 'Checked' flag auto-cleared when ErrAsOutParam is destructed.
1084/// }
1085/// @endcode
1086///
1087/// ErrorAsOutParameter takes an Error* rather than Error& so that it can be
1088/// used with optional Errors (Error pointers that are allowed to be null). If
1089/// ErrorAsOutParameter took an Error reference, an instance would have to be
1090/// created inside every condition that verified that Error was non-null. By
1091/// taking an Error pointer we can just create one instance at the top of the
1092/// function.
1093class ErrorAsOutParameter {
1094public:
1095 ErrorAsOutParameter(Error *Err) : Err(Err) {
1096 // Raise the checked bit if Err is success.
1097 if (Err)
1098 (void)!!*Err;
1099 }
1100
1101 ~ErrorAsOutParameter() {
1102 // Clear the checked bit.
1103 if (Err && !*Err)
1104 *Err = Error::success();
1105 }
1106
1107private:
1108 Error *Err;
1109};
1110
1111/// Helper for Expected<T>s used as out-parameters.
1112///
1113/// See ErrorAsOutParameter.
1114template <typename T>
1115class ExpectedAsOutParameter {
1116public:
1117 ExpectedAsOutParameter(Expected<T> *ValOrErr)
1118 : ValOrErr(ValOrErr) {
1119 if (ValOrErr)
1120 (void)!!*ValOrErr;
1121 }
1122
1123 ~ExpectedAsOutParameter() {
1124 if (ValOrErr)
1125 ValOrErr->setUnchecked();
1126 }
1127
1128private:
1129 Expected<T> *ValOrErr;
1130};
1131
1132/// This class wraps a std::error_code in a Error.
1133///
1134/// This is useful if you're writing an interface that returns a Error
1135/// (or Expected) and you want to call code that still returns
1136/// std::error_codes.
1137class ECError : public ErrorInfo<ECError> {
1138 friend Error errorCodeToError(std::error_code);
1139
1140 virtual void anchor() override;
1141
1142public:
1143 void setErrorCode(std::error_code EC) { this->EC = EC; }
1144 std::error_code convertToErrorCode() const override { return EC; }
1145 void log(raw_ostream &OS) const override { OS << EC.message(); }
1146
1147 // Used by ErrorInfo::classID.
1148 static char ID;
1149
1150protected:
1151 ECError() = default;
1152 ECError(std::error_code EC) : EC(EC) {}
1153
1154 std::error_code EC;
1155};
1156
1157/// The value returned by this function can be returned from convertToErrorCode
1158/// for Error values where no sensible translation to std::error_code exists.
1159/// It should only be used in this situation, and should never be used where a
1160/// sensible conversion to std::error_code is available, as attempts to convert
1161/// to/from this error will result in a fatal error. (i.e. it is a programmatic
1162///error to try to convert such a value).
1163std::error_code inconvertibleErrorCode();
1164
1165/// Helper for converting an std::error_code to a Error.
1166Error errorCodeToError(std::error_code EC);
1167
1168/// Helper for converting an ECError to a std::error_code.
1169///
1170/// This method requires that Err be Error() or an ECError, otherwise it
1171/// will trigger a call to abort().
1172std::error_code errorToErrorCode(Error Err);
1173
1174/// Convert an ErrorOr<T> to an Expected<T>.
1175template <typename T> Expected<T> errorOrToExpected(ErrorOr<T> &&EO) {
1176 if (auto EC = EO.getError())
1177 return errorCodeToError(EC);
1178 return std::move(*EO);
1179}
1180
1181/// Convert an Expected<T> to an ErrorOr<T>.
1182template <typename T> ErrorOr<T> expectedToErrorOr(Expected<T> &&E) {
1183 if (auto Err = E.takeError())
1184 return errorToErrorCode(std::move(Err));
1185 return std::move(*E);
1186}
1187
1188/// This class wraps a string in an Error.
1189///
1190/// StringError is useful in cases where the client is not expected to be able
1191/// to consume the specific error message programmatically (for example, if the
1192/// error message is to be presented to the user).
1193///
1194/// StringError can also be used when additional information is to be printed
1195/// along with a error_code message. Depending on the constructor called, this
1196/// class can either display:
1197/// 1. the error_code message (ECError behavior)
1198/// 2. a string
1199/// 3. the error_code message and a string
1200///
1201/// These behaviors are useful when subtyping is required; for example, when a
1202/// specific library needs an explicit error type. In the example below,
1203/// PDBError is derived from StringError:
1204///
1205/// @code{.cpp}
1206/// Expected<int> foo() {
1207/// return llvm::make_error<PDBError>(pdb_error_code::dia_failed_loading,
1208/// "Additional information");
1209/// }
1210/// @endcode
1211///
1212class StringError : public ErrorInfo<StringError> {
1213public:
1214 static char ID;
1215
1216 // Prints EC + S and converts to EC
1217 StringError(std::error_code EC, const Twine &S = Twine());
1218
1219 // Prints S and converts to EC
1220 StringError(const Twine &S, std::error_code EC);
1221
1222 void log(raw_ostream &OS) const override;
1223 std::error_code convertToErrorCode() const override;
1224
1225 const std::string &getMessage() const { return Msg; }
1226
1227private:
1228 std::string Msg;
1229 std::error_code EC;
1230 const bool PrintMsgOnly = false;
1231};
1232
1233/// Create formatted StringError object.
1234template <typename... Ts>
1235inline Error createStringError(std::error_code EC, char const *Fmt,
1236 const Ts &... Vals) {
1237 std::string Buffer;
1238 raw_string_ostream Stream(Buffer);
1239 Stream << format(Fmt, Vals...);
1240 return make_error<StringError>(Stream.str(), EC);
1241}
1242
1243Error createStringError(std::error_code EC, char const *Msg);
1244
1245inline Error createStringError(std::error_code EC, const Twine &S) {
1246 return createStringError(EC, S.str().c_str());
1247}
1248
1249template <typename... Ts>
1250inline Error createStringError(std::errc EC, char const *Fmt,
1251 const Ts &... Vals) {
1252 return createStringError(std::make_error_code(EC), Fmt, Vals...);
1253}
1254
1255/// This class wraps a filename and another Error.
1256///
1257/// In some cases, an error needs to live along a 'source' name, in order to
1258/// show more detailed information to the user.
1259class FileError final : public ErrorInfo<FileError> {
1260
1261 friend Error createFileError(const Twine &, Error);
1262 friend Error createFileError(const Twine &, size_t, Error);
1263
1264public:
1265 void log(raw_ostream &OS) const override {
1266 assert(Err && !FileName.empty() && "Trying to log after takeError().")((void)0);
1267 OS << "'" << FileName << "': ";
1268 if (Line.hasValue())
1269 OS << "line " << Line.getValue() << ": ";
1270 Err->log(OS);
1271 }
1272
1273 StringRef getFileName() { return FileName; }
1274
1275 Error takeError() { return Error(std::move(Err)); }
1276
1277 std::error_code convertToErrorCode() const override;
1278
1279 // Used by ErrorInfo::classID.
1280 static char ID;
1281
1282private:
1283 FileError(const Twine &F, Optional<size_t> LineNum,
1284 std::unique_ptr<ErrorInfoBase> E) {
1285 assert(E && "Cannot create FileError from Error success value.")((void)0);
1286 assert(!F.isTriviallyEmpty() &&((void)0)
1287 "The file name provided to FileError must not be empty.")((void)0);
1288 FileName = F.str();
1289 Err = std::move(E);
1290 Line = std::move(LineNum);
1291 }
1292
1293 static Error build(const Twine &F, Optional<size_t> Line, Error E) {
1294 std::unique_ptr<ErrorInfoBase> Payload;
1295 handleAllErrors(std::move(E),
1296 [&](std::unique_ptr<ErrorInfoBase> EIB) -> Error {
1297 Payload = std::move(EIB);
1298 return Error::success();
1299 });
1300 return Error(
1301 std::unique_ptr<FileError>(new FileError(F, Line, std::move(Payload))));
1302 }
1303
1304 std::string FileName;
1305 Optional<size_t> Line;
1306 std::unique_ptr<ErrorInfoBase> Err;
1307};
1308
1309/// Concatenate a source file path and/or name with an Error. The resulting
1310/// Error is unchecked.
1311inline Error createFileError(const Twine &F, Error E) {
1312 return FileError::build(F, Optional<size_t>(), std::move(E));
1313}
1314
1315/// Concatenate a source file path and/or name with line number and an Error.
1316/// The resulting Error is unchecked.
1317inline Error createFileError(const Twine &F, size_t Line, Error E) {
1318 return FileError::build(F, Optional<size_t>(Line), std::move(E));
1319}
1320
1321/// Concatenate a source file path and/or name with a std::error_code
1322/// to form an Error object.
1323inline Error createFileError(const Twine &F, std::error_code EC) {
1324 return createFileError(F, errorCodeToError(EC));
1325}
1326
1327/// Concatenate a source file path and/or name with line number and
1328/// std::error_code to form an Error object.
1329inline Error createFileError(const Twine &F, size_t Line, std::error_code EC) {
1330 return createFileError(F, Line, errorCodeToError(EC));
1331}
1332
1333Error createFileError(const Twine &F, ErrorSuccess) = delete;
1334
1335/// Helper for check-and-exit error handling.
1336///
1337/// For tool use only. NOT FOR USE IN LIBRARY CODE.
1338///
1339class ExitOnError {
1340public:
1341 /// Create an error on exit helper.
1342 ExitOnError(std::string Banner = "", int DefaultErrorExitCode = 1)
1343 : Banner(std::move(Banner)),
1344 GetExitCode([=](const Error &) { return DefaultErrorExitCode; }) {}
1345
1346 /// Set the banner string for any errors caught by operator().
1347 void setBanner(std::string Banner) { this->Banner = std::move(Banner); }
1348
1349 /// Set the exit-code mapper function.
1350 void setExitCodeMapper(std::function<int(const Error &)> GetExitCode) {
1351 this->GetExitCode = std::move(GetExitCode);
1352 }
1353
1354 /// Check Err. If it's in a failure state log the error(s) and exit.
1355 void operator()(Error Err) const { checkError(std::move(Err)); }
1356
1357 /// Check E. If it's in a success state then return the contained value. If
1358 /// it's in a failure state log the error(s) and exit.
1359 template <typename T> T operator()(Expected<T> &&E) const {
1360 checkError(E.takeError());
1361 return std::move(*E);
1362 }
1363
1364 /// Check E. If it's in a success state then return the contained reference. If
1365 /// it's in a failure state log the error(s) and exit.
1366 template <typename T> T& operator()(Expected<T&> &&E) const {
1367 checkError(E.takeError());
1368 return *E;
1369 }
1370
1371private:
1372 void checkError(Error Err) const {
1373 if (Err) {
1374 int ExitCode = GetExitCode(Err);
1375 logAllUnhandledErrors(std::move(Err), errs(), Banner);
1376 exit(ExitCode);
1377 }
1378 }
1379
1380 std::string Banner;
1381 std::function<int(const Error &)> GetExitCode;
1382};
1383
1384/// Conversion from Error to LLVMErrorRef for C error bindings.
1385inline LLVMErrorRef wrap(Error Err) {
1386 return reinterpret_cast<LLVMErrorRef>(Err.takePayload().release());
1387}
1388
1389/// Conversion from LLVMErrorRef to Error for C error bindings.
1390inline Error unwrap(LLVMErrorRef ErrRef) {
1391 return Error(std::unique_ptr<ErrorInfoBase>(
1392 reinterpret_cast<ErrorInfoBase *>(ErrRef)));
1393}
1394
1395} // end namespace llvm
1396
1397#endif // LLVM_SUPPORT_ERROR_H