[PCH] Store the offsets of source location file entries and go through them

in ASTReader::validateFileEntries().

This avoids going through all source location entries and fixes the performance regression.
Many thanks to Doug for the hint!
(rdar://9530587)

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@132481 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 18 insertions, 2 deletions

diff --git a/lib/Serialization/ASTWriter.cpp b/lib/Serialization/ASTWriter.cpp
index 297115c491..3bb27cff0f 100644
--- a/lib/Serialization/ASTWriter.cpp
+++ b/lib/Serialization/ASTWriter.cpp
@@ -1449,6 +1449,9 @@ void ASTWriter::WriteSourceManagerBlock(SourceManager &SourceMgr,
   // Write out the source location entry table. We skip the first
   // entry, which is always the same dummy entry.
   std::vector<uint32_t> SLocEntryOffsets;
+  // Write out the offsets of only source location file entries.
+  // We will go through them in ASTReader::validateFileEntries().
+  std::vector<uint32_t> SLocFileEntryOffsets;
   RecordData PreloadSLocs;
   unsigned BaseSLocID = Chain ? Chain->getTotalNumSLocs() : 0;
   SLocEntryOffsets.reserve(SourceMgr.sloc_entry_size() - 1 - BaseSLocID);
@@ -1463,9 +1466,10 @@ void ASTWriter::WriteSourceManagerBlock(SourceManager &SourceMgr,
     // Figure out which record code to use.
     unsigned Code;
     if (SLoc->isFile()) {
-      if (SLoc->getFile().getContentCache()->OrigEntry)
+      if (SLoc->getFile().getContentCache()->OrigEntry) {
         Code = SM_SLOC_FILE_ENTRY;
-      else
+        SLocFileEntryOffsets.push_back(Stream.GetCurrentBitNo());
+      } else
         Code = SM_SLOC_BUFFER_ENTRY;
     } else
       Code = SM_SLOC_INSTANTIATION_ENTRY;
@@ -1565,6 +1569,18 @@ void ASTWriter::WriteSourceManagerBlock(SourceManager &SourceMgr,
   Record.push_back(SourceMgr.getNextOffset() - BaseOffset);
   Stream.EmitRecordWithBlob(SLocOffsetsAbbrev, Record, data(SLocEntryOffsets));
 
+  Abbrev = new BitCodeAbbrev();
+  Abbrev->Add(BitCodeAbbrevOp(FILE_SOURCE_LOCATION_OFFSETS));
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 16)); // # of slocs
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // offsets
+  unsigned SLocFileOffsetsAbbrev = Stream.EmitAbbrev(Abbrev);
+
+  Record.clear();
+  Record.push_back(FILE_SOURCE_LOCATION_OFFSETS);
+  Record.push_back(SLocFileEntryOffsets.size());
+  Stream.EmitRecordWithBlob(SLocFileOffsetsAbbrev, Record,
+                            data(SLocFileEntryOffsets));
+
   // Write the source location entry preloads array, telling the AST
   // reader which source locations entries it should load eagerly.
   Stream.EmitRecord(SOURCE_LOCATION_PRELOADS, PreloadSLocs);