Cosmetic changes

Author: rintaro

include/swift/AST/Module.h

@@ -728,6 +728,7 @@ class ModuleDecl : public DeclContext, public TypeDecl {
     return ReverseFullNameIterator(this);
   }
 
+  /// Calls \p callback for each source file of the module.
   void collectBasicSourceFileInfo(
       llvm::function_ref<void(const BasicSourceFileInfo &)> callback);
 

lib/Serialization/ModuleFile.cpp

@@ -968,11 +968,15 @@ void ModuleFile::collectBasicSourceFileInfo(
   auto *Cursor = Core->SourceFileListData.bytes_begin();
   auto *End = Core->SourceFileListData.bytes_end();
   while (Cursor < End) {
+    // FilePath (byte offset in 'SourceLocsTextData').
     auto fileID = endian::readNext<uint32_t, little, unaligned>(Cursor);
+    // InterfaceHash (fixed length string).
     auto fpStr = StringRef{reinterpret_cast<const char *>(Cursor),
                            Fingerprint::DIGEST_LENGTH};
     Cursor += Fingerprint::DIGEST_LENGTH;
+    // LastModified (seconds since epoch).
     auto timestamp = endian::readNext<uint64_t, little, unaligned>(Cursor);
+    // FileSize (num of bytes).
     auto fileSize = endian::readNext<uint64_t, little, unaligned>(Cursor);
 
     assert(fileID < Core->SourceLocsTextData.size());

lib/Serialization/SerializeDoc.cpp

@@ -790,7 +790,7 @@ static void emitFileListRecord(llvm::BitstreamWriter &Out,
   struct SourceFileListWriter {
     StringWriter &FWriter;
 
-    llvm::SmallString<1024> Buffer;
+    llvm::SmallString<0> Buffer;
     llvm::StringSet<> seenFilenames;
 
     void emitSourceFileInfo(const BasicSourceFileInfo &info) {
@@ -803,29 +803,39 @@ static void emitFileListRecord(llvm::BitstreamWriter &Out,
         return;
 
       auto fileID = FWriter.getTextOffset(absolutePath);
-      auto timestamp = std::chrono::duration_cast<std::chrono::seconds>(info.LastModified.time_since_epoch()).count();
+      auto fingerprintStr = info.InterfaceHash.getRawValue();
+      auto timestamp = std::chrono::duration_cast<std::chrono::seconds>(
+                           info.LastModified.time_since_epoch())
+                           .count();
 
       llvm::raw_svector_ostream out(Buffer);
       endian::Writer writer(out, little);
+      // FilePath.
       writer.write<uint32_t>(fileID);
-      out << info.InterfaceHash.getRawValue();
+      // InterfaceHash (fixed length string).
+      assert(fingerprintStr.size() == Fingerprint::DIGEST_LENGTH);
+      out << fingerprintStr;
+      // LastModified.
       writer.write<uint64_t>(timestamp);
+      // FileSize.
       writer.write<uint64_t>(info.FileSize);
     }
 
-    SourceFileListWriter(StringWriter &FWriter) : FWriter(FWriter) {}
+    SourceFileListWriter(StringWriter &FWriter) : FWriter(FWriter) {
+      Buffer.reserve(1024);
+    }
   } writer(FWriter);
 
   if (SourceFile *SF = MSF.dyn_cast<SourceFile *>()) {
     BasicSourceFileInfo info;
-    SmallString<128> stash;
     if (info.populate(SF))
       return;
     writer.emitSourceFileInfo(info);
   } else {
     auto *M = MSF.get<ModuleDecl *>();
-    M->collectBasicSourceFileInfo(
-        [&](const BasicSourceFileInfo &info) { writer.emitSourceFileInfo(info); });
+    M->collectBasicSourceFileInfo([&](const BasicSourceFileInfo &info) {
+      writer.emitSourceFileInfo(info);
+    });
   }
 
   const decl_locs_block::SourceFileListLayout FileList(Out);

lib/Serialization/SourceInfoFormat.h

@@ -75,16 +75,16 @@ namespace decl_locs_block {
     SOURCE_FILE_LIST,
   };
 
+  using SourceFileListLayout = BCRecordLayout<
+    SOURCE_FILE_LIST, // record ID
+    BCBlob            // An array of fixed size 'BasicSourceFileInfo' data.
+  >;
+
   using BasicDeclLocsLayout = BCRecordLayout<
     BASIC_DECL_LOCS, // record ID
     BCBlob           // an array of fixed size location data
   >;
 
-  using SourceFileListLayout = BCRecordLayout<
-    SOURCE_FILE_LIST, // record ID
-    BCBlob            // An array of string offsets in TextDataLayout
-  >;
-
   using DeclUSRSLayout = BCRecordLayout<
     DECL_USRS,         // record ID
     BCVBR<16>,         // table offset within the blob (an llvm::OnDiskHashTable)