Serialize Fingerprints in Swift Modules

lib/Serialization/ModuleFormat.h

@@ -56,7 +56,7 @@ const uint16_t SWIFTMODULE_VERSION_MAJOR = 0;
 /// describe what change you made. The content of this comment isn't important;
 /// it just ensures a conflict if two people change the module format.
 /// Don't worry about adhering to the 80-column limit for this line.
-const uint16_t SWIFTMODULE_VERSION_MINOR = 586; // allow errors in modules
+const uint16_t SWIFTMODULE_VERSION_MINOR = 587; // fingerprints in modules
 
 /// A standard hash seed used for all string hashes in a serialized module.
 ///
@@ -2010,6 +2010,7 @@ namespace index_block {
     PRECEDENCE_GROUPS,
     NESTED_TYPE_DECLS,
     DECL_MEMBER_NAMES,
+    DECL_FINGERPRINTS,
 
     ORDERED_TOP_LEVEL_DECLS,
 
@@ -2017,7 +2018,7 @@ namespace index_block {
     CLANG_TYPE_OFFSETS,
     LastRecordKind = CLANG_TYPE_OFFSETS,
   };
-  
+
   constexpr const unsigned RecordIDFieldWidth = 5;
   static_assert(LastRecordKind < (1 << RecordIDFieldWidth),
                 "not enough bits for all record kinds");
@@ -2078,6 +2079,12 @@ namespace index_block {
     RecordIDField,        // record ID
     BCArray<DeclIDField>  // list of decls by ID
   >;
+
+  using DeclFingerprintsLayout = BCRecordLayout<
+    DECL_FINGERPRINTS, // record ID
+    BCVBR<16>,   // table offset within the blob (see below)
+    BCBlob       // map from member DeclIDs to strings
+  >;
 }
 
 /// \sa DECL_MEMBER_TABLES_BLOCK_ID