[pdb/lld] Write a valid FPM.

The PDB reserves certain blocks for the FPM that describe which
blocks in the file are allocated and which are free.  We weren't
filling that out at all, and in some cases we were even stomping
it with incorrect data.  This patch writes a correct FPM.

Differential Revision: https://reviews.llvm.org/D36235

llvm-svn: 309896

1 files changed, 55 insertions, 0 deletions

diff --git a/llvm/unittests/DebugInfo/MSF/MappedBlockStreamTest.cpp b/llvm/unittests/DebugInfo/MSF/MappedBlockStreamTest.cpp
index 94cd347d09a..94c4898551d 100644
--- a/llvm/unittests/DebugInfo/MSF/MappedBlockStreamTest.cpp
+++ b/llvm/unittests/DebugInfo/MSF/MappedBlockStreamTest.cpp
@@ -16,6 +16,7 @@
 #include "llvm/Support/BinaryStreamWriter.h"
 #include "llvm/Testing/Support/Error.h"
 
+#include "gmock/gmock.h"
 #include "gtest/gtest.h"
 
 #include <unordered_map>
@@ -494,5 +495,59 @@ TEST(MappedBlockStreamTest, DataLivesAfterStreamDestruction) {
 
   EXPECT_EQ(Str[0], Str[1]);
 }
+} // namespace
+
+MATCHER_P3(BlockIsFilledWith, Layout, BlockIndex, Byte, "succeeded") {
+  uint64_t Offset = msf::blockToOffset(BlockIndex, Layout.SB->BlockSize);
+  ArrayRef<uint8_t> BufferRef = makeArrayRef(arg);
+  BufferRef = BufferRef.slice(Offset, Layout.SB->BlockSize);
+  return llvm::all_of(BufferRef, [this](uint8_t B) { return B == Byte; });
+}
+
+namespace {
+TEST(MappedBlockStreamTest, CreateFpmStream) {
+  BumpPtrAllocator Allocator;
+  SuperBlock SB;
+  MSFLayout L;
+  L.SB = &SB;
+
+  SB.FreeBlockMapBlock = 1;
+  SB.BlockSize = 4096;
+
+  constexpr uint32_t NumFileBlocks = 4096 * 4;
+
+  std::vector<uint8_t> MsfBuffer(NumFileBlocks * SB.BlockSize);
+  MutableBinaryByteStream MsfStream(MsfBuffer, llvm::support::little);
+
+  SB.NumBlocks = NumFileBlocks;
+  auto FpmStream =
+      WritableMappedBlockStream::createFpmStream(L, MsfStream, Allocator);
+  // 4096 * 4 / 8 = 2048 bytes of FPM data is needed to describe 4096 * 4
+  // blocks.  This translates to 1 FPM block.
+  EXPECT_EQ(2048u, FpmStream->getLength());
+  EXPECT_EQ(1u, FpmStream->getStreamLayout().Blocks.size());
+  EXPECT_EQ(1u, FpmStream->getStreamLayout().Blocks[0]);
+  // All blocks from FPM1 should be 1 initialized, and all blocks from FPM2
+  // should be 0 initialized (since we requested the main FPM, not the alt FPM)
+  for (int I = 0; I < 4; ++I) {
+    EXPECT_THAT(MsfBuffer, BlockIsFilledWith(L, 1 + I * SB.BlockSize, 0xFF));
+    EXPECT_THAT(MsfBuffer, BlockIsFilledWith(L, 2 + I * SB.BlockSize, 0));
+  }
+
+  ::memset(MsfBuffer.data(), 0, MsfBuffer.size());
+  FpmStream =
+      WritableMappedBlockStream::createFpmStream(L, MsfStream, Allocator, true);
+  // 4096 * 4 / 8 = 2048 bytes of FPM data is needed to describe 4096 * 4
+  // blocks.  This translates to 1 FPM block.
+  EXPECT_EQ(2048u, FpmStream->getLength());
+  EXPECT_EQ(1u, FpmStream->getStreamLayout().Blocks.size());
+  EXPECT_EQ(2u, FpmStream->getStreamLayout().Blocks[0]);
+  // All blocks from FPM2 should be 1 initialized, and all blocks from FPM1
+  // should be 0 initialized (since we requested the alt FPM, not the main FPM)
+  for (int I = 0; I < 4; ++I) {
+    EXPECT_THAT(MsfBuffer, BlockIsFilledWith(L, 1 + I * SB.BlockSize, 0));
+    EXPECT_THAT(MsfBuffer, BlockIsFilledWith(L, 2 + I * SB.BlockSize, 0xFF));
+  }
+}
 
 } // end anonymous namespace