1 //===- DbiModuleList.cpp - PDB module information list --------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #include "llvm/DebugInfo/PDB/Native/DbiModuleList.h"
11 #include "llvm/ADT/StringRef.h"
12 #include "llvm/ADT/iterator_range.h"
13 #include "llvm/DebugInfo/PDB/Native/RawError.h"
14 #include "llvm/Support/BinaryStreamReader.h"
15 #include "llvm/Support/Error.h"
22 using namespace llvm::pdb;
24 DbiModuleSourceFilesIterator::DbiModuleSourceFilesIterator(
25 const DbiModuleList &Modules, uint32_t Modi, uint16_t Filei)
26 : Modules(&Modules), Modi(Modi), Filei(Filei) {
30 bool DbiModuleSourceFilesIterator::
31 operator==(const DbiModuleSourceFilesIterator &R) const {
32 // incompatible iterators are never equal
36 // If they're compatible, and they're both ends, then they're equal.
37 if (isEnd() && R.isEnd())
40 // If one is an end and the other is not, they're not equal.
41 if (isEnd() != R.isEnd())
45 // - They're compatible
46 // - They're not *both* end iterators
47 // - Their endness is the same.
48 // Thus, they're compatible iterators pointing to a valid file on the same
49 // module. All we need to check are the file indices.
50 assert(Modules == R.Modules);
51 assert(Modi == R.Modi);
55 return (Filei == R.Filei);
58 bool DbiModuleSourceFilesIterator::
59 operator<(const DbiModuleSourceFilesIterator &R) const {
60 assert(isCompatible(R));
62 // It's not sufficient to compare the file indices, because default
63 // constructed iterators could be equal to iterators with valid indices. To
64 // account for this, early-out if they're equal.
68 return Filei < R.Filei;
71 std::ptrdiff_t DbiModuleSourceFilesIterator::
72 operator-(const DbiModuleSourceFilesIterator &R) const {
73 assert(isCompatible(R));
76 // If they're both end iterators, the distance is 0.
77 if (isEnd() && R.isEnd())
82 // At this point, R cannot be end, but *this can, which means that *this
83 // might be a universal end iterator with none of its fields set. So in that
84 // case have to rely on R as the authority to figure out how many files there
85 // are to compute the distance.
86 uint32_t Thisi = Filei;
88 uint32_t RealModi = R.Modi;
89 Thisi = R.Modules->getSourceFileCount(RealModi);
92 assert(Thisi >= R.Filei);
93 return Thisi - R.Filei;
96 DbiModuleSourceFilesIterator &DbiModuleSourceFilesIterator::
97 operator+=(std::ptrdiff_t N) {
101 assert(Filei <= Modules->getSourceFileCount(Modi));
106 DbiModuleSourceFilesIterator &DbiModuleSourceFilesIterator::
107 operator-=(std::ptrdiff_t N) {
108 // Note that we can subtract from an end iterator, but not a universal end
110 assert(!isUniversalEnd());
118 void DbiModuleSourceFilesIterator::setValue() {
124 uint32_t Off = Modules->ModuleInitialFileIndex[Modi] + Filei;
125 auto ExpectedValue = Modules->getFileName(Off);
126 if (!ExpectedValue) {
127 consumeError(ExpectedValue.takeError());
128 Filei = Modules->getSourceFileCount(Modi);
130 ThisValue = *ExpectedValue;
133 bool DbiModuleSourceFilesIterator::isEnd() const {
134 if (isUniversalEnd())
138 assert(Modi <= Modules->getModuleCount());
139 assert(Filei <= Modules->getSourceFileCount(Modi));
141 if (Modi == Modules->getModuleCount())
143 if (Filei == Modules->getSourceFileCount(Modi))
148 bool DbiModuleSourceFilesIterator::isUniversalEnd() const { return !Modules; }
150 bool DbiModuleSourceFilesIterator::isCompatible(
151 const DbiModuleSourceFilesIterator &R) const {
152 // Universal iterators are compatible with any other iterator.
153 if (isUniversalEnd() || R.isUniversalEnd())
156 // At this point, neither iterator is a universal end iterator, although one
157 // or both might be non-universal end iterators. Regardless, the module index
158 // is valid, so they are compatible if and only if they refer to the same
160 return Modi == R.Modi;
163 Error DbiModuleList::initialize(BinaryStreamRef ModInfo,
164 BinaryStreamRef FileInfo) {
165 if (auto EC = initializeModInfo(ModInfo))
167 if (auto EC = initializeFileInfo(FileInfo))
170 return Error::success();
173 Error DbiModuleList::initializeModInfo(BinaryStreamRef ModInfo) {
174 ModInfoSubstream = ModInfo;
176 if (ModInfo.getLength() == 0)
177 return Error::success();
179 BinaryStreamReader Reader(ModInfo);
181 if (auto EC = Reader.readArray(Descriptors, ModInfo.getLength()))
184 return Error::success();
187 Error DbiModuleList::initializeFileInfo(BinaryStreamRef FileInfo) {
188 FileInfoSubstream = FileInfo;
190 if (FileInfo.getLength() == 0)
191 return Error::success();
193 BinaryStreamReader FISR(FileInfo);
194 if (auto EC = FISR.readObject(FileInfoHeader))
197 // First is an array of `NumModules` module indices. This does not seem to be
198 // used for anything meaningful, so we ignore it.
199 FixedStreamArray<support::ulittle16_t> ModuleIndices;
200 if (auto EC = FISR.readArray(ModuleIndices, FileInfoHeader->NumModules))
202 if (auto EC = FISR.readArray(ModFileCountArray, FileInfoHeader->NumModules))
205 // Compute the real number of source files. We can't trust the value in
206 // `FileInfoHeader->NumSourceFiles` because it is a unit16, and the sum of all
207 // source file counts might be larger than a unit16. So we compute the real
208 // count by summing up the individual counts.
209 uint32_t NumSourceFiles = 0;
210 for (auto Count : ModFileCountArray)
211 NumSourceFiles += Count;
213 // In the reference implementation, this array is where the pointer documented
214 // at the definition of ModuleInfoHeader::FileNameOffs points to. Note that
215 // although the field in ModuleInfoHeader is ignored this array is not, as it
216 // is the authority on where each filename begins in the names buffer.
217 if (auto EC = FISR.readArray(FileNameOffsets, NumSourceFiles))
220 if (auto EC = FISR.readStreamRef(NamesBuffer))
223 auto DescriptorIter = Descriptors.begin();
224 uint32_t NextFileIndex = 0;
225 ModuleInitialFileIndex.resize(FileInfoHeader->NumModules);
226 ModuleDescriptorOffsets.resize(FileInfoHeader->NumModules);
227 for (size_t I = 0; I < FileInfoHeader->NumModules; ++I) {
228 assert(DescriptorIter != Descriptors.end());
229 ModuleInitialFileIndex[I] = NextFileIndex;
230 ModuleDescriptorOffsets[I] = DescriptorIter.offset();
232 NextFileIndex += ModFileCountArray[I];
236 assert(DescriptorIter == Descriptors.end());
237 assert(NextFileIndex == NumSourceFiles);
239 return Error::success();
242 uint32_t DbiModuleList::getModuleCount() const {
243 return FileInfoHeader->NumModules;
246 uint32_t DbiModuleList::getSourceFileCount() const {
247 return FileNameOffsets.size();
250 uint16_t DbiModuleList::getSourceFileCount(uint32_t Modi) const {
251 return ModFileCountArray[Modi];
254 DbiModuleDescriptor DbiModuleList::getModuleDescriptor(uint32_t Modi) const {
255 assert(Modi < getModuleCount());
256 uint32_t Offset = ModuleDescriptorOffsets[Modi];
257 auto Iter = Descriptors.at(Offset);
258 assert(Iter != Descriptors.end());
262 iterator_range<DbiModuleSourceFilesIterator>
263 DbiModuleList::source_files(uint32_t Modi) const {
264 return make_range<DbiModuleSourceFilesIterator>(
265 DbiModuleSourceFilesIterator(*this, Modi, 0),
266 DbiModuleSourceFilesIterator());
269 Expected<StringRef> DbiModuleList::getFileName(uint32_t Index) const {
270 BinaryStreamReader Names(NamesBuffer);
271 if (Index >= getSourceFileCount())
272 return make_error<RawError>(raw_error_code::index_out_of_bounds);
274 uint32_t FileOffset = FileNameOffsets[Index];
275 Names.setOffset(FileOffset);
277 if (auto EC = Names.readCString(Name))
278 return std::move(EC);