Revert r301986 (and subsequent r301987).

The patch is failing to add StringTableStreamBuilder.h, but that isn't
even discovered because the corresponding StringTableStreamBuilder.cpp
isn't added to any CMakeLists.txt file and thus never built. I think
this patch is just incomplete.

llvm-svn: 302002

1 files changed, 37 insertions, 57 deletions

diff --git a/llvm/lib/DebugInfo/PDB/Native/PDBStringTable.cpp b/llvm/lib/DebugInfo/PDB/Native/PDBStringTable.cpp
index ee32f61..fd3e69d 100644
--- a/llvm/lib/DebugInfo/PDB/Native/PDBStringTable.cpp
+++ b/llvm/lib/DebugInfo/PDB/Native/PDBStringTable.cpp
@@ -1,4 +1,5 @@
-//===- PDBStringTable.cpp - PDB String Table ---------------------*- C++-*-===//
+//===- PDBStringTable.cpp - PDB String Table -----------------------*- C++
+//-*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -10,7 +11,6 @@
 #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"
@@ -21,91 +21,71 @@ using namespace llvm;
 using namespace llvm::support;
 using namespace llvm::pdb;
 
-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; }
+PDBStringTable::PDBStringTable() {}
+
+Error PDBStringTable::load(BinaryStreamReader &Stream) {
+  ByteSize = Stream.getLength();
 
-Error PDBStringTable::readHeader(BinaryStreamReader &Reader) {
-  if (auto EC = Reader.readObject(Header))
+  const PDBStringTableHeader *H;
+  if (auto EC = Stream.readObject(H))
     return EC;
 
-  if (Header->Signature != PDBStringTableSignature)
+  if (H->Signature != PDBStringTableSignature)
     return make_error<RawError>(raw_error_code::corrupt_file,
                                 "Invalid hash table signature");
-  if (Header->HashVersion != 1 && Header->HashVersion != 2)
+  if (H->HashVersion != 1 && H->HashVersion != 2)
     return make_error<RawError>(raw_error_code::corrupt_file,
                                 "Unsupported hash version");
 
-  assert(Reader.bytesRemaining() == 0);
-  return Error::success();
-}
-
-Error PDBStringTable::readStrings(BinaryStreamReader &Reader) {
-  if (auto EC = Strings.initialize(Reader)) {
+  Signature = H->Signature;
+  HashVersion = H->HashVersion;
+  if (auto EC = Stream.readStreamRef(NamesBuffer, H->ByteSize))
     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 = Reader.readObject(HashCount))
+  if (auto EC = Stream.readObject(HashCount))
     return EC;
 
-  if (auto EC = Reader.readArray(IDs, *HashCount)) {
+  if (auto EC = Stream.readArray(IDs, *HashCount))
     return joinErrors(std::move(EC),
                       make_error<RawError>(raw_error_code::corrupt_file,
                                            "Could not read bucket array"));
-  }
 
-  return Error::success();
-}
-
-Error PDBStringTable::readEpilogue(BinaryStreamReader &Reader) {
-  if (auto EC = Reader.readInteger(NameCount))
-    return EC;
-
-  assert(Reader.bytesRemaining() == 0);
-  return Error::success();
-}
-
-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;
+  if (Stream.bytesRemaining() < sizeof(support::ulittle32_t))
+    return make_error<RawError>(raw_error_code::corrupt_file,
+                                "Missing name count");
 
-  // 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))
+  if (auto EC = Stream.readInteger(NameCount))
     return EC;
 
-  std::tie(SectionReader, Reader) = Reader.split(sizeof(uint32_t));
-  if (auto EC = readEpilogue(SectionReader))
-    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; }
+
 StringRef PDBStringTable::getStringForID(uint32_t ID) const {
-  return Strings.getString(ID);
+  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;
 }
 
 uint32_t PDBStringTable::getIDForString(StringRef Str) const {
-  uint32_t Hash =
-      (Header->HashVersion == 1) ? hashStringV1(Str) : hashStringV2(Str);
+  uint32_t Hash = (HashVersion == 1) ? hashStringV1(Str) : hashStringV2(Str);
   size_t Count = IDs.size();
   uint32_t Start = Hash % Count;
   for (size_t I = 0; I < Count; ++I) {