[NFC] Use Fingerprints When Computing the Interface Hash

Author: CodaFi

include/swift/AST/AbstractSourceFileDepGraphFactory.h

@@ -32,7 +32,7 @@ class AbstractSourceFileDepGraphFactory {
   const std::string swiftDeps;
 
   /// The fingerprint of the whole file
-  const std::string fileFingerprint;
+  Fingerprint fileFingerprint;
 
   /// For debugging
   const bool emitDotFileAfterConstruction;
@@ -47,7 +47,7 @@ class AbstractSourceFileDepGraphFactory {
   /// See the instance variable comments for explanation.
   AbstractSourceFileDepGraphFactory(bool hadCompilationError,
                                     StringRef swiftDeps,
-                                    StringRef fileFingerprint,
+                                    Fingerprint fileFingerprint,
                                     bool emitDotFileAfterConstruction,
                                     DiagnosticEngine &diags);
 

include/swift/AST/SourceFile.h

@@ -525,12 +525,10 @@ class SourceFile final : public FileUnit {
   }
 
   /// Output this file's interface hash into the provided string buffer.
-  void getInterfaceHash(llvm::SmallString<32> &str) const;
+  Fingerprint getInterfaceHash() const;
 
   void dumpInterfaceHash(llvm::raw_ostream &out) {
-    llvm::SmallString<32> str;
-    getInterfaceHash(str);
-    out << str << '\n';
+    out << getInterfaceHash() << '\n';
   }
 
   /// If this source file has been told to collect its parsed tokens, retrieve

lib/AST/AbstractSourceFileDepGraphFactory.cpp

@@ -34,10 +34,10 @@ using namespace fine_grained_dependencies;
 
 AbstractSourceFileDepGraphFactory::AbstractSourceFileDepGraphFactory(
     bool hadCompilationError, StringRef swiftDeps,
-    StringRef fileFingerprint, bool emitDotFileAfterConstruction,
+    Fingerprint fileFingerprint, bool emitDotFileAfterConstruction,
     DiagnosticEngine &diags)
     : hadCompilationError(hadCompilationError), swiftDeps(swiftDeps.str()),
-      fileFingerprint(fileFingerprint.str()),
+      fileFingerprint(fileFingerprint),
       emitDotFileAfterConstruction(emitDotFileAfterConstruction), diags(diags) {
 }
 

lib/AST/FrontendSourceFileDepGraphFactory.cpp

@@ -218,24 +218,10 @@ FrontendSourceFileDepGraphFactory::FrontendSourceFileDepGraphFactory(
     const SourceFile *SF, StringRef outputPath,
     const DependencyTracker &depTracker, const bool alsoEmitDotFile)
     : AbstractSourceFileDepGraphFactory(
-          SF->getASTContext().hadError(), outputPath, getInterfaceHash(SF),
+          SF->getASTContext().hadError(), outputPath, SF->getInterfaceHash(),
           alsoEmitDotFile, SF->getASTContext().Diags),
       SF(SF), depTracker(depTracker) {}
 
-/// Centralize the invariant that the fingerprint of the whole file is the
-/// interface hash
-std::string
-FrontendSourceFileDepGraphFactory::getFingerprint(const SourceFile *SF) {
-  return getInterfaceHash(SF);
-}
-
-std::string
-FrontendSourceFileDepGraphFactory::getInterfaceHash(const SourceFile *SF) {
-  llvm::SmallString<32> interfaceHash;
-  SF->getInterfaceHash(interfaceHash);
-  return interfaceHash.str().str();
-}
-
 //==============================================================================
 // MARK: FrontendSourceFileDepGraphFactory - adding collections of defined Decls
 //==============================================================================
@@ -520,7 +506,9 @@ void FrontendSourceFileDepGraphFactory::addAllUsedDecls() {
 ModuleDepGraphFactory::ModuleDepGraphFactory(const ModuleDecl *Mod,
                                              bool emitDot)
     : AbstractSourceFileDepGraphFactory(Mod->getASTContext().hadError(),
-                                        Mod->getNameStr(), "0xBADBEEF", emitDot,
+                                        Mod->getNameStr(),
+                                        Fingerprint(std::string{Fingerprint::DIGEST_LENGTH, '0'}),
+                                        emitDot,
                                         Mod->getASTContext().Diags),
       Mod(Mod) {}
 

lib/AST/FrontendSourceFileDepGraphFactory.h

@@ -34,9 +34,6 @@ class FrontendSourceFileDepGraphFactory
   ~FrontendSourceFileDepGraphFactory() override = default;
 
 private:
-  static std::string getFingerprint(const SourceFile *SF);
-  static std::string getInterfaceHash(const SourceFile *SF);
-
   void addAllDefinedDecls() override;
   void addAllUsedDecls() override;
 };

lib/AST/Module.cpp

@@ -1074,15 +1074,15 @@ LookupConformanceInModuleRequest::evaluate(
   return ProtocolConformanceRef(conformance);
 }
 
-void SourceFile::getInterfaceHash(llvm::SmallString<32> &str) const {
+Fingerprint SourceFile::getInterfaceHash() const {
   assert(hasInterfaceHash() && "Interface hash not enabled");
   auto &eval = getASTContext().evaluator;
   auto *mutableThis = const_cast<SourceFile *>(this);
   auto md5 = *evaluateOrDefault(eval, ParseSourceFileRequest{mutableThis}, {})
                   .InterfaceHash;
   llvm::MD5::MD5Result result;
   md5.final(result);
-  llvm::MD5::stringifyResult(result, str);
+  return Fingerprint{std::move(result)};
 }
 
 syntax::SourceFileSyntax SourceFile::getSyntaxRoot() const {

lib/IDE/CompletionInstance.cpp

@@ -295,12 +295,10 @@ static bool areAnyDependentFilesInvalidated(
 /// Note that we don't care about local types (i.e. type declarations inside
 /// function bodies, closures, or top level statement bodies) because they are
 /// not visible from other functions where the completion is happening.
-void getInterfaceHashIncludingTypeMembers(SourceFile *SF,
-                                          llvm::SmallString<32> &str) {
+static Fingerprint getInterfaceHashIncludingTypeMembers(const SourceFile *SF) {
   /// FIXME: Gross. Hashing multiple "hash" values.
   llvm::MD5 hash;
-  SF->getInterfaceHash(str);
-  hash.update(str);
+  hash.update(SF->getInterfaceHash().getRawValue());
 
   std::function<void(IterableDeclContext *)> hashTypeBodyFingerprints =
       [&](IterableDeclContext *IDC) {
@@ -318,7 +316,7 @@ void getInterfaceHashIncludingTypeMembers(SourceFile *SF,
 
   llvm::MD5::MD5Result result;
   hash.final(result);
-  str = result.digest();
+  return Fingerprint{std::move(result)};
 }
 
 } // namespace
@@ -397,10 +395,8 @@ bool CompletionInstance::performCachedOperationIfPossible(
   switch (newInfo.Kind) {
   case CodeCompletionDelayedDeclKind::FunctionBody: {
     // If the interface has changed, AST must be refreshed.
-    llvm::SmallString<32> oldInterfaceHash{};
-    llvm::SmallString<32> newInterfaceHash{};
-    getInterfaceHashIncludingTypeMembers(oldSF, oldInterfaceHash);
-    getInterfaceHashIncludingTypeMembers(tmpSF, newInterfaceHash);
+    const auto oldInterfaceHash = getInterfaceHashIncludingTypeMembers(oldSF);
+    const auto newInterfaceHash = getInterfaceHashIncludingTypeMembers(tmpSF);
     if (oldInterfaceHash != newInterfaceHash)
       return false;