[msf] Create LLVMDebugInfoMsf

This provides a better layering of responsibilities among different
aspects of PDB writing code.  Some of the MSF related code was
contained in CodeView, and some was in PDB prior to this.  Further,
we were often saying PDB when we meant MSF, and the two are
actually independent of each other since in theory you can have
other types of data besides PDB data in an MSF.  So, this patch
separates the MSF specific code into its own library, with no
dependencies on anything else, and DebugInfoCodeView and
DebugInfoPDB take dependencies on DebugInfoMsf.

llvm-svn: 276458

1 files changed, 279 insertions, 0 deletions

diff --git a/llvm/lib/DebugInfo/Msf/MsfBuilder.cpp b/llvm/lib/DebugInfo/Msf/MsfBuilder.cpp
new file mode 100644
index 00000000000..e6f15d8877e
--- /dev/null
+++ b/llvm/lib/DebugInfo/Msf/MsfBuilder.cpp
@@ -0,0 +1,279 @@
+//===- MSFBuilder.cpp - MSF Directory & Metadata Builder --------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/DebugInfo/Msf/MsfBuilder.h"
+#include "llvm/DebugInfo/Msf/MsfError.h"
+
+using namespace llvm;
+using namespace llvm::msf;
+using namespace llvm::support;
+
+namespace {
+const uint32_t kSuperBlockBlock = 0;
+const uint32_t kFreePageMap0Block = 1;
+const uint32_t kFreePageMap1Block = 2;
+const uint32_t kNumReservedPages = 3;
+
+const uint32_t kDefaultBlockMapAddr = kNumReservedPages;
+}
+
+MsfBuilder::MsfBuilder(uint32_t BlockSize, uint32_t MinBlockCount, bool CanGrow,
+                       BumpPtrAllocator &Allocator)
+    : Allocator(Allocator), IsGrowable(CanGrow), BlockSize(BlockSize),
+      MininumBlocks(MinBlockCount), BlockMapAddr(kDefaultBlockMapAddr),
+      FreeBlocks(MinBlockCount, true) {
+  FreeBlocks[kSuperBlockBlock] = false;
+  FreeBlocks[kFreePageMap0Block] = false;
+  FreeBlocks[kFreePageMap1Block] = false;
+  FreeBlocks[BlockMapAddr] = false;
+}
+
+Expected<MsfBuilder> MsfBuilder::create(BumpPtrAllocator &Allocator,
+                                        uint32_t BlockSize,
+                                        uint32_t MinBlockCount, bool CanGrow) {
+  if (!isValidBlockSize(BlockSize))
+    return make_error<MsfError>(msf_error_code::invalid_format,
+                                "The requested block size is unsupported");
+
+  return MsfBuilder(BlockSize,
+                    std::max(MinBlockCount, msf::getMinimumBlockCount()),
+                    CanGrow, Allocator);
+}
+
+Error MsfBuilder::setBlockMapAddr(uint32_t Addr) {
+  if (Addr == BlockMapAddr)
+    return Error::success();
+
+  if (Addr >= FreeBlocks.size()) {
+    if (!IsGrowable)
+      return make_error<MsfError>(msf_error_code::insufficient_buffer,
+                                  "Cannot grow the number of blocks");
+    FreeBlocks.resize(Addr + 1);
+  }
+
+  if (!isBlockFree(Addr))
+    return make_error<MsfError>(
+        msf_error_code::block_in_use,
+        "Requested block map address is already in use");
+  FreeBlocks[BlockMapAddr] = true;
+  FreeBlocks[Addr] = false;
+  BlockMapAddr = Addr;
+  return Error::success();
+}
+
+void MsfBuilder::setFreePageMap(uint32_t Fpm) { FreePageMap = Fpm; }
+
+void MsfBuilder::setUnknown1(uint32_t Unk1) { Unknown1 = Unk1; }
+
+Error MsfBuilder::setDirectoryBlocksHint(ArrayRef<uint32_t> DirBlocks) {
+  for (auto B : DirectoryBlocks)
+    FreeBlocks[B] = true;
+  for (auto B : DirBlocks) {
+    if (!isBlockFree(B)) {
+      return make_error<MsfError>(msf_error_code::unspecified,
+                                  "Attempt to reuse an allocated block");
+    }
+    FreeBlocks[B] = false;
+  }
+
+  DirectoryBlocks = DirBlocks;
+  return Error::success();
+}
+
+Error MsfBuilder::allocateBlocks(uint32_t NumBlocks,
+                                 MutableArrayRef<uint32_t> Blocks) {
+  if (NumBlocks == 0)
+    return Error::success();
+
+  uint32_t NumFreeBlocks = FreeBlocks.count();
+  if (NumFreeBlocks < NumBlocks) {
+    if (!IsGrowable)
+      return make_error<MsfError>(msf_error_code::insufficient_buffer,
+                                  "There are no free Blocks in the file");
+    uint32_t AllocBlocks = NumBlocks - NumFreeBlocks;
+    FreeBlocks.resize(AllocBlocks + FreeBlocks.size(), true);
+  }
+
+  int I = 0;
+  int Block = FreeBlocks.find_first();
+  do {
+    assert(Block != -1 && "We ran out of Blocks!");
+
+    uint32_t NextBlock = static_cast<uint32_t>(Block);
+    Blocks[I++] = NextBlock;
+    FreeBlocks.reset(NextBlock);
+    Block = FreeBlocks.find_next(Block);
+  } while (--NumBlocks > 0);
+  return Error::success();
+}
+
+uint32_t MsfBuilder::getNumUsedBlocks() const {
+  return getTotalBlockCount() - getNumFreeBlocks();
+}
+
+uint32_t MsfBuilder::getNumFreeBlocks() const { return FreeBlocks.count(); }
+
+uint32_t MsfBuilder::getTotalBlockCount() const { return FreeBlocks.size(); }
+
+bool MsfBuilder::isBlockFree(uint32_t Idx) const { return FreeBlocks[Idx]; }
+
+Error MsfBuilder::addStream(uint32_t Size, ArrayRef<uint32_t> Blocks) {
+  // Add a new stream mapped to the specified blocks.  Verify that the specified
+  // blocks are both necessary and sufficient for holding the requested number
+  // of bytes, and verify that all requested blocks are free.
+  uint32_t ReqBlocks = bytesToBlocks(Size, BlockSize);
+  if (ReqBlocks != Blocks.size())
+    return make_error<MsfError>(
+        msf_error_code::invalid_format,
+        "Incorrect number of blocks for requested stream size");
+  for (auto Block : Blocks) {
+    if (Block >= FreeBlocks.size())
+      FreeBlocks.resize(Block + 1, true);
+
+    if (!FreeBlocks.test(Block))
+      return make_error<MsfError>(
+          msf_error_code::unspecified,
+          "Attempt to re-use an already allocated block");
+  }
+  // Mark all the blocks occupied by the new stream as not free.
+  for (auto Block : Blocks) {
+    FreeBlocks.reset(Block);
+  }
+  StreamData.push_back(std::make_pair(Size, Blocks));
+  return Error::success();
+}
+
+Error MsfBuilder::addStream(uint32_t Size) {
+  uint32_t ReqBlocks = bytesToBlocks(Size, BlockSize);
+  std::vector<uint32_t> NewBlocks;
+  NewBlocks.resize(ReqBlocks);
+  if (auto EC = allocateBlocks(ReqBlocks, NewBlocks))
+    return EC;
+  StreamData.push_back(std::make_pair(Size, NewBlocks));
+  return Error::success();
+}
+
+Error MsfBuilder::setStreamSize(uint32_t Idx, uint32_t Size) {
+  uint32_t OldSize = getStreamSize(Idx);
+  if (OldSize == Size)
+    return Error::success();
+
+  uint32_t NewBlocks = bytesToBlocks(Size, BlockSize);
+  uint32_t OldBlocks = bytesToBlocks(OldSize, BlockSize);
+
+  if (NewBlocks > OldBlocks) {
+    uint32_t AddedBlocks = NewBlocks - OldBlocks;
+    // If we're growing, we have to allocate new Blocks.
+    std::vector<uint32_t> AddedBlockList;
+    AddedBlockList.resize(AddedBlocks);
+    if (auto EC = allocateBlocks(AddedBlocks, AddedBlockList))
+      return EC;
+    auto &CurrentBlocks = StreamData[Idx].second;
+    CurrentBlocks.insert(CurrentBlocks.end(), AddedBlockList.begin(),
+                         AddedBlockList.end());
+  } else if (OldBlocks > NewBlocks) {
+    // For shrinking, free all the Blocks in the Block map, update the stream
+    // data, then shrink the directory.
+    uint32_t RemovedBlocks = OldBlocks - NewBlocks;
+    auto CurrentBlocks = ArrayRef<uint32_t>(StreamData[Idx].second);
+    auto RemovedBlockList = CurrentBlocks.drop_front(NewBlocks);
+    for (auto P : RemovedBlockList)
+      FreeBlocks[P] = true;
+    StreamData[Idx].second = CurrentBlocks.drop_back(RemovedBlocks);
+  }
+
+  StreamData[Idx].first = Size;
+  return Error::success();
+}
+
+uint32_t MsfBuilder::getNumStreams() const { return StreamData.size(); }
+
+uint32_t MsfBuilder::getStreamSize(uint32_t StreamIdx) const {
+  return StreamData[StreamIdx].first;
+}
+
+ArrayRef<uint32_t> MsfBuilder::getStreamBlocks(uint32_t StreamIdx) const {
+  return StreamData[StreamIdx].second;
+}
+
+uint32_t MsfBuilder::computeDirectoryByteSize() const {
+  // The directory has the following layout, where each item is a ulittle32_t:
+  //    NumStreams
+  //    StreamSizes[NumStreams]
+  //    StreamBlocks[NumStreams][]
+  uint32_t Size = sizeof(ulittle32_t);             // NumStreams
+  Size += StreamData.size() * sizeof(ulittle32_t); // StreamSizes
+  for (const auto &D : StreamData) {
+    uint32_t ExpectedNumBlocks = bytesToBlocks(D.first, BlockSize);
+    assert(ExpectedNumBlocks == D.second.size() &&
+           "Unexpected number of blocks");
+    Size += ExpectedNumBlocks * sizeof(ulittle32_t);
+  }
+  return Size;
+}
+
+Expected<Layout> MsfBuilder::build() {
+  Layout L;
+  L.SB = Allocator.Allocate<SuperBlock>();
+  std::memcpy(L.SB->MagicBytes, Magic, sizeof(Magic));
+  L.SB->BlockMapAddr = BlockMapAddr;
+  L.SB->BlockSize = BlockSize;
+  L.SB->NumDirectoryBytes = computeDirectoryByteSize();
+  L.SB->FreeBlockMapBlock = FreePageMap;
+  L.SB->Unknown1 = Unknown1;
+
+  uint32_t NumDirectoryBlocks =
+      bytesToBlocks(L.SB->NumDirectoryBytes, BlockSize);
+  if (NumDirectoryBlocks > DirectoryBlocks.size()) {
+    // Our hint wasn't enough to satisfy the entire directory.  Allocate
+    // remaining pages.
+    std::vector<uint32_t> ExtraBlocks;
+    uint32_t NumExtraBlocks = NumDirectoryBlocks - DirectoryBlocks.size();
+    ExtraBlocks.resize(NumExtraBlocks);
+    if (auto EC = allocateBlocks(NumExtraBlocks, ExtraBlocks))
+      return std::move(EC);
+    DirectoryBlocks.insert(DirectoryBlocks.end(), ExtraBlocks.begin(),
+                           ExtraBlocks.end());
+  } else if (NumDirectoryBlocks < DirectoryBlocks.size()) {
+    uint32_t NumUnnecessaryBlocks = DirectoryBlocks.size() - NumDirectoryBlocks;
+    for (auto B :
+         ArrayRef<uint32_t>(DirectoryBlocks).drop_back(NumUnnecessaryBlocks))
+      FreeBlocks[B] = true;
+    DirectoryBlocks.resize(NumDirectoryBlocks);
+  }
+
+  // Don't set the number of blocks in the file until after allocating Blocks
+  // for the directory, since the allocation might cause the file to need to
+  // grow.
+  L.SB->NumBlocks = FreeBlocks.size();
+
+  ulittle32_t *DirBlocks = Allocator.Allocate<ulittle32_t>(NumDirectoryBlocks);
+  std::uninitialized_copy_n(DirectoryBlocks.begin(), NumDirectoryBlocks,
+                            DirBlocks);
+  L.DirectoryBlocks = ArrayRef<ulittle32_t>(DirBlocks, NumDirectoryBlocks);
+
+  // The stream sizes should be re-allocated as a stable pointer and the stream
+  // map should have each of its entries allocated as a separate stable pointer.
+  if (StreamData.size() > 0) {
+    ulittle32_t *Sizes = Allocator.Allocate<ulittle32_t>(StreamData.size());
+    L.StreamSizes = ArrayRef<ulittle32_t>(Sizes, StreamData.size());
+    L.StreamMap.resize(StreamData.size());
+    for (uint32_t I = 0; I < StreamData.size(); ++I) {
+      Sizes[I] = StreamData[I].first;
+      ulittle32_t *BlockList =
+          Allocator.Allocate<ulittle32_t>(StreamData[I].second.size());
+      std::uninitialized_copy_n(StreamData[I].second.begin(),
+                                StreamData[I].second.size(), BlockList);
+      L.StreamMap[I] =
+          ArrayRef<ulittle32_t>(BlockList, StreamData[I].second.size());
+    }
+  }
+
+  return L;
+}