Resubmit r301986 and r301987 "Add codeview::StringTable"

This was reverted due to a "missing" file, but in reality
what happened was that I renamed a file, and then due to
a merge conflict both the old file and the new file got
added to the repository.  This led to an unused cpp file
being in the repo and not referenced by any CMakeLists.txt
but #including a .h file that wasn't in the repo.  In an
even more unfortunate coincidence, CMake didn't report the
unused cpp file because it was in a subdirectory of the
folder with the CMakeLists.txt, and not in the same directory
as any CMakeLists.txt.

The presence of the unused file was then breaking certain
tools that determine file lists by globbing rather than
by what's specified in CMakeLists.txt

In any case, the fix is to just remove the unused file from
the patch set.

llvm-svn: 302042

1 files changed, 57 insertions, 37 deletions

diff --git a/llvm/lib/DebugInfo/PDB/Native/PDBStringTable.cpp b/llvm/lib/DebugInfo/PDB/Native/PDBStringTable.cpp
index fd3e69d..ee32f61 100644
--- a/llvm/lib/DebugInfo/PDB/Native/PDBStringTable.cpp
+++ b/llvm/lib/DebugInfo/PDB/Native/PDBStringTable.cpp
@@ -1,5 +1,4 @@
-//===- PDBStringTable.cpp - PDB String Table -----------------------*- C++
-//-*-===//
+//===- PDBStringTable.cpp - PDB String Table ---------------------*- C++-*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -11,6 +10,7 @@
 #include "llvm/DebugInfo/PDB/Native/PDBStringTable.h"
 
 #include "llvm/ADT/ArrayRef.h"
+#include "llvm/DebugInfo/MSF/MappedBlockStream.h"
 #include "llvm/DebugInfo/PDB/Native/Hash.h"
 #include "llvm/DebugInfo/PDB/Native/RawError.h"
 #include "llvm/DebugInfo/PDB/Native/RawTypes.h"
@@ -21,71 +21,91 @@ using namespace llvm;
 using namespace llvm::support;
 using namespace llvm::pdb;
 
-PDBStringTable::PDBStringTable() {}
-
-Error PDBStringTable::load(BinaryStreamReader &Stream) {
-  ByteSize = Stream.getLength();
+uint32_t PDBStringTable::getByteSize() const { return ByteSize; }
+uint32_t PDBStringTable::getNameCount() const { return NameCount; }
+uint32_t PDBStringTable::getHashVersion() const { return Header->HashVersion; }
+uint32_t PDBStringTable::getSignature() const { return Header->Signature; }
 
-  const PDBStringTableHeader *H;
-  if (auto EC = Stream.readObject(H))
+Error PDBStringTable::readHeader(BinaryStreamReader &Reader) {
+  if (auto EC = Reader.readObject(Header))
     return EC;
 
-  if (H->Signature != PDBStringTableSignature)
+  if (Header->Signature != PDBStringTableSignature)
     return make_error<RawError>(raw_error_code::corrupt_file,
                                 "Invalid hash table signature");
-  if (H->HashVersion != 1 && H->HashVersion != 2)
+  if (Header->HashVersion != 1 && Header->HashVersion != 2)
     return make_error<RawError>(raw_error_code::corrupt_file,
                                 "Unsupported hash version");
 
-  Signature = H->Signature;
-  HashVersion = H->HashVersion;
-  if (auto EC = Stream.readStreamRef(NamesBuffer, H->ByteSize))
+  assert(Reader.bytesRemaining() == 0);
+  return Error::success();
+}
+
+Error PDBStringTable::readStrings(BinaryStreamReader &Reader) {
+  if (auto EC = Strings.initialize(Reader)) {
     return joinErrors(std::move(EC),
                       make_error<RawError>(raw_error_code::corrupt_file,
                                            "Invalid hash table byte length"));
+  }
+
+  assert(Reader.bytesRemaining() == 0);
+  return Error::success();
+}
 
+Error PDBStringTable::readHashTable(BinaryStreamReader &Reader) {
   const support::ulittle32_t *HashCount;
-  if (auto EC = Stream.readObject(HashCount))
+  if (auto EC = Reader.readObject(HashCount))
     return EC;
 
-  if (auto EC = Stream.readArray(IDs, *HashCount))
+  if (auto EC = Reader.readArray(IDs, *HashCount)) {
     return joinErrors(std::move(EC),
                       make_error<RawError>(raw_error_code::corrupt_file,
                                            "Could not read bucket array"));
+  }
 
-  if (Stream.bytesRemaining() < sizeof(support::ulittle32_t))
-    return make_error<RawError>(raw_error_code::corrupt_file,
-                                "Missing name count");
+  return Error::success();
+}
 
-  if (auto EC = Stream.readInteger(NameCount))
+Error PDBStringTable::readEpilogue(BinaryStreamReader &Reader) {
+  if (auto EC = Reader.readInteger(NameCount))
     return EC;
 
-  if (Stream.bytesRemaining() > 0)
-    return make_error<RawError>(raw_error_code::stream_too_long,
-                                "Unexpected bytes found in string table");
-
+  assert(Reader.bytesRemaining() == 0);
   return Error::success();
 }
 
-uint32_t PDBStringTable::getByteSize() const { return ByteSize; }
+Error PDBStringTable::reload(BinaryStreamReader &Reader) {
+
+  BinaryStreamReader SectionReader;
+
+  std::tie(SectionReader, Reader) = Reader.split(sizeof(PDBStringTableHeader));
+  if (auto EC = readHeader(SectionReader))
+    return EC;
+
+  std::tie(SectionReader, Reader) = Reader.split(Header->ByteSize);
+  if (auto EC = readStrings(SectionReader))
+    return EC;
+
+  // We don't know how long the hash table is until we parse it, so let the
+  // function responsible for doing that figure it out.
+  if (auto EC = readHashTable(Reader))
+    return EC;
+
+  std::tie(SectionReader, Reader) = Reader.split(sizeof(uint32_t));
+  if (auto EC = readEpilogue(SectionReader))
+    return EC;
+
+  assert(Reader.bytesRemaining() == 0);
+  return Error::success();
+}
 
 StringRef PDBStringTable::getStringForID(uint32_t ID) const {
-  if (ID == IDs[0])
-    return StringRef();
-
-  // NamesBuffer is a buffer of null terminated strings back to back.  ID is
-  // the starting offset of the string we're looking for.  So just seek into
-  // the desired offset and a read a null terminated stream from that offset.
-  StringRef Result;
-  BinaryStreamReader NameReader(NamesBuffer);
-  NameReader.setOffset(ID);
-  if (auto EC = NameReader.readCString(Result))
-    consumeError(std::move(EC));
-  return Result;
+  return Strings.getString(ID);
 }
 
 uint32_t PDBStringTable::getIDForString(StringRef Str) const {
-  uint32_t Hash = (HashVersion == 1) ? hashStringV1(Str) : hashStringV2(Str);
+  uint32_t Hash =
+      (Header->HashVersion == 1) ? hashStringV1(Str) : hashStringV2(Str);
   size_t Count = IDs.size();
   uint32_t Start = Hash % Count;
   for (size_t I = 0; I < Count; ++I) {