1 files changed, 173 insertions, 0 deletions
diff --git a/contrib/llvm/lib/DebugInfo/PDB/Raw/PublicsStream.cpp b/contrib/llvm/lib/DebugInfo/PDB/Raw/PublicsStream.cpp
new file mode 100644
index 0000000..af3d2d0
--- /dev/null
+++ b/contrib/llvm/lib/DebugInfo/PDB/Raw/PublicsStream.cpp
@@ -0,0 +1,173 @@
+//===- PublicsStream.cpp - PDB Public Symbol Stream -----------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// The data structures defined in this file are based on the reference
+// implementation which is available at
+// https://github.com/Microsoft/microsoft-pdb/blob/master/PDB/dbi/gsi.h
+//
+// When you are reading the reference source code, you'd find the
+// information below useful.
+//
+//  - ppdb1->m_fMinimalDbgInfo seems to be always true.
+//  - SMALLBUCKETS macro is defined.
+//
+// The reference doesn't compile, so I learned just by reading code.
+// It's not guaranteed to be correct.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/DebugInfo/PDB/Raw/PublicsStream.h"
+
+#include "llvm/DebugInfo/CodeView/CodeView.h"
+#include "llvm/DebugInfo/CodeView/StreamReader.h"
+#include "llvm/DebugInfo/CodeView/TypeRecord.h"
+#include "llvm/DebugInfo/PDB/Raw/IndexedStreamData.h"
+#include "llvm/DebugInfo/PDB/Raw/MappedBlockStream.h"
+#include "llvm/DebugInfo/PDB/Raw/PDBFile.h"
+#include "llvm/DebugInfo/PDB/Raw/RawConstants.h"
+#include "llvm/DebugInfo/PDB/Raw/RawError.h"
+#include "llvm/DebugInfo/PDB/Raw/SymbolStream.h"
+
+#include "llvm/ADT/BitVector.h"
+#include "llvm/Support/Endian.h"
+#include "llvm/Support/Format.h"
+#include "llvm/Support/MathExtras.h"
+
+using namespace llvm;
+using namespace llvm::support;
+using namespace llvm::pdb;
+
+
+static const unsigned IPHR_HASH = 4096;
+
+// This is PSGSIHDR struct defined in
+// https://github.com/Microsoft/microsoft-pdb/blob/master/PDB/dbi/gsi.h
+struct PublicsStream::HeaderInfo {
+  ulittle32_t SymHash;
+  ulittle32_t AddrMap;
+  ulittle32_t NumThunks;
+  ulittle32_t SizeOfThunk;
+  ulittle16_t ISectThunkTable;
+  char Padding[2];
+  ulittle32_t OffThunkTable;
+  ulittle32_t NumSections;
+};
+
+// This is GSIHashHdr.
+struct PublicsStream::GSIHashHeader {
+  enum : unsigned {
+    HdrSignature = ~0U,
+    HdrVersion = 0xeffe0000 + 19990810,
+  };
+  ulittle32_t VerSignature;
+  ulittle32_t VerHdr;
+  ulittle32_t HrSize;
+  ulittle32_t NumBuckets;
+};
+
+PublicsStream::PublicsStream(PDBFile &File,
+                             std::unique_ptr<MappedBlockStream> Stream)
+    : Pdb(File), Stream(std::move(Stream)) {}
+
+PublicsStream::~PublicsStream() {}
+
+uint32_t PublicsStream::getSymHash() const { return Header->SymHash; }
+uint32_t PublicsStream::getAddrMap() const { return Header->AddrMap; }
+
+// Publics stream contains fixed-size headers and a serialized hash table.
+// This implementation is not complete yet. It reads till the end of the
+// stream so that we verify the stream is at least not corrupted. However,
+// we skip over the hash table which we believe contains information about
+// public symbols.
+Error PublicsStream::reload() {
+  codeview::StreamReader Reader(*Stream);
+
+  // Check stream size.
+  if (Reader.bytesRemaining() < sizeof(HeaderInfo) + sizeof(GSIHashHeader))
+    return make_error<RawError>(raw_error_code::corrupt_file,
+                                "Publics Stream does not contain a header.");
+
+  // Read PSGSIHDR and GSIHashHdr structs.
+  if (Reader.readObject(Header))
+    return make_error<RawError>(raw_error_code::corrupt_file,
+                                "Publics Stream does not contain a header.");
+
+  if (Reader.readObject(HashHdr))
+    return make_error<RawError>(raw_error_code::corrupt_file,
+                                "Publics Stream does not contain a header.");
+
+  // An array of HashRecord follows. Read them.
+  if (HashHdr->HrSize % sizeof(PSHashRecord))
+    return make_error<RawError>(raw_error_code::corrupt_file,
+                                "Invalid HR array size.");
+  uint32_t NumHashRecords = HashHdr->HrSize / sizeof(PSHashRecord);
+  if (auto EC = Reader.readArray(HashRecords, NumHashRecords))
+    return joinErrors(std::move(EC),
+                      make_error<RawError>(raw_error_code::corrupt_file,
+                                           "Could not read an HR array"));
+
+  // A bitmap of a fixed length follows.
+  size_t BitmapSizeInBits = alignTo(IPHR_HASH + 1, 32);
+  uint32_t NumBitmapEntries = BitmapSizeInBits / 8;
+  if (auto EC = Reader.readBytes(Bitmap, NumBitmapEntries))
+    return joinErrors(std::move(EC),
+                      make_error<RawError>(raw_error_code::corrupt_file,
+                                           "Could not read a bitmap."));
+  for (uint8_t B : Bitmap)
+    NumBuckets += countPopulation(B);
+
+  // We don't yet understand the following data structures completely,
+  // but we at least know the types and sizes. Here we are trying
+  // to read the stream till end so that we at least can detect
+  // corrupted streams.
+
+  // Hash buckets follow.
+  if (auto EC = Reader.readArray(HashBuckets, NumBuckets))
+    return joinErrors(std::move(EC),
+                      make_error<RawError>(raw_error_code::corrupt_file,
+                                           "Hash buckets corrupted."));
+
+  // Something called "address map" follows.
+  uint32_t NumAddressMapEntries = Header->AddrMap / sizeof(uint32_t);
+  if (auto EC = Reader.readArray(AddressMap, NumAddressMapEntries))
+    return joinErrors(std::move(EC),
+                      make_error<RawError>(raw_error_code::corrupt_file,
+                                           "Could not read an address map."));
+
+  // Something called "thunk map" follows.
+  if (auto EC = Reader.readArray(ThunkMap, Header->NumThunks))
+    return joinErrors(std::move(EC),
+                      make_error<RawError>(raw_error_code::corrupt_file,
+                                           "Could not read a thunk map."));
+
+  // Something called "section map" follows.
+  if (auto EC = Reader.readArray(SectionOffsets, Header->NumSections))
+    return joinErrors(std::move(EC),
+                      make_error<RawError>(raw_error_code::corrupt_file,
+                                           "Could not read a section map."));
+
+  if (Reader.bytesRemaining() > 0)
+    return make_error<RawError>(raw_error_code::corrupt_file,
+                                "Corrupted publics stream.");
+  return Error::success();
+}
+
+iterator_range<codeview::CVSymbolArray::Iterator>
+PublicsStream::getSymbols(bool *HadError) const {
+  auto SymbolS = Pdb.getPDBSymbolStream();
+  if (SymbolS.takeError()) {
+    codeview::CVSymbolArray::Iterator Iter;
+    return llvm::make_range(Iter, Iter);
+  }
+  SymbolStream &SS = SymbolS.get();
+
+  return SS.getSymbols(HadError);
+}
+
+Error PublicsStream::commit() { return Error::success(); }