Merge pull request #7594 from apple/jan_svoboda/sloc-entry-opt

Author: jansvoboda11

clang/include/clang/Basic/SourceLocation.h

@@ -58,6 +58,7 @@ class FileID {
   friend class ASTWriter;
   friend class ASTReader;
   friend class SourceManager;
+  friend class SourceManagerTestHelper;
 
   static FileID get(int V) {
     FileID F;

clang/include/clang/Basic/SourceManager.h

@@ -504,6 +504,14 @@ class SLocEntry {
     return Expansion;
   }
 
+  /// Creates an incomplete SLocEntry that is only able to report its offset.
+  static SLocEntry getOffsetOnly(SourceLocation::UIntTy Offset) {
+    assert(!(Offset & (1ULL << OffsetBits)) && "Offset is too large");
+    SLocEntry E;
+    E.Offset = Offset;
+    return E;
+  }
+
   static SLocEntry get(SourceLocation::UIntTy Offset, const FileInfo &FI) {
     assert(!(Offset & (1ULL << OffsetBits)) && "Offset is too large");
     SLocEntry E;
@@ -538,6 +546,12 @@ class ExternalSLocEntrySource {
   /// entry from being loaded.
   virtual bool ReadSLocEntry(int ID) = 0;
 
+  /// Get the index ID for the loaded SourceLocation offset.
+  ///
+  /// \returns Invalid index ID (0) if an error occurred that prevented the
+  /// SLocEntry  from being loaded.
+  virtual int getSLocEntryID(SourceLocation::UIntTy SLocOffset) = 0;
+
   /// Retrieve the module import location and name for the given ID, if
   /// in fact it was loaded from a module (rather than, say, a precompiled
   /// header).
@@ -706,6 +720,11 @@ class SourceManager : public RefCountedBase<SourceManager> {
   /// use (-ID - 2).
   SmallVector<SrcMgr::SLocEntry, 0> LoadedSLocEntryTable;
 
+  /// For each allocation in LoadedSLocEntryTable, we keep the first FileID.
+  /// We assume exactly one allocation per AST file, and use that to determine
+  /// whether two FileIDs come from the same AST file.
+  SmallVector<FileID, 0> LoadedSLocEntryAllocBegin;
+
   /// The starting offset of the next local SLocEntry.
   ///
   /// This is LocalSLocEntryTable.back().Offset + the size of that entry.
@@ -728,6 +747,12 @@ class SourceManager : public RefCountedBase<SourceManager> {
   /// Same indexing as LoadedSLocEntryTable.
   llvm::BitVector SLocEntryLoaded;
 
+  /// A bitmap that indicates whether the entries of LoadedSLocEntryTable
+  /// have already had their offset loaded from the external source.
+  ///
+  /// Superset of SLocEntryLoaded. Same indexing as SLocEntryLoaded.
+  llvm::BitVector SLocEntryOffsetLoaded;
+
   /// An external source for source location entries.
   ExternalSLocEntrySource *ExternalSLocEntries = nullptr;
 
@@ -1654,6 +1679,11 @@ class SourceManager : public RefCountedBase<SourceManager> {
   isInTheSameTranslationUnit(std::pair<FileID, unsigned> &LOffs,
                              std::pair<FileID, unsigned> &ROffs) const;
 
+  /// Determines whether the two decomposed source location is in the same TU.
+  bool isInTheSameTranslationUnitImpl(
+      const std::pair<FileID, unsigned> &LOffs,
+      const std::pair<FileID, unsigned> &ROffs) const;
+
   /// Determines the order of 2 source locations in the "source location
   /// address space".
   bool isBeforeInSLocAddrSpace(SourceLocation LHS, SourceLocation RHS) const {

clang/include/clang/Serialization/ASTBitCodes.h

@@ -51,7 +51,7 @@ const unsigned VERSION_MAJOR = 29;
 /// for the previous version could still support reading the new
 /// version by ignoring new kinds of subblocks), this number
 /// should be increased.
-const unsigned VERSION_MINOR = 0;
+const unsigned VERSION_MINOR = 1;
 
 /// An ID number that refers to an identifier in an AST file.
 ///
@@ -535,13 +535,7 @@ enum ASTRecordTypes {
   /// of source-location information.
   SOURCE_LOCATION_OFFSETS = 14,
 
-  /// Record code for the set of source location entries
-  /// that need to be preloaded by the AST reader.
-  ///
-  /// This set contains the source location entry for the
-  /// predefines buffer and for any file entries that need to be
-  /// preloaded.
-  SOURCE_LOCATION_PRELOADS = 15,
+  // ID 15 used to be for source location entry preloads.
 
   /// Record code for the set of ext_vector type names.
   EXT_VECTOR_DECLS = 16,

clang/include/clang/Serialization/ASTReader.h

@@ -2163,6 +2163,12 @@ class ASTReader
 
   /// Read the source location entry with index ID.
   bool ReadSLocEntry(int ID) override;
+  /// Get the index ID for the loaded SourceLocation offset.
+  int getSLocEntryID(SourceLocation::UIntTy SLocOffset) override;
+  /// Try to read the offset of the SLocEntry at the given index in the given
+  /// module file.
+  llvm::Expected<SourceLocation::UIntTy> readSLocOffset(ModuleFile *F,
+                                                        unsigned Index);
 
   /// Retrieve the module import location and module name for the
   /// given source manager entry ID.

clang/include/clang/Serialization/ModuleFile.h

@@ -303,9 +303,6 @@ class ModuleFile {
   /// AST file.
   const uint32_t *SLocEntryOffsets = nullptr;
 
-  /// SLocEntries that we're going to preload.
-  SmallVector<uint64_t, 4> PreloadSLocEntries;
-
   /// Remapping table for source locations in this module.
   ContinuousRangeMap<SourceLocation::UIntTy, SourceLocation::IntTy, 2>
       SLocRemap;