Frontend: add a front-end option to specify module names for which we prefer to loading via interfaces

ABI checker imports Swift frameworks by using Swift interfaces for various
reasons. The existing way of controlling preferred importing mechanism is by
setting an environment variable (SWIFT_FORCE_MODULE_LOADING), which may lead
to performance issues because the stdlib could also be loaded in this way.

This patch adds a new front-end option to specify module names for
which we prefer to importing via Swift interface. The option currently is only
accessible via swift-api-digester.

rdar://54559888

Author: nkcsgexi

include/swift/Frontend/FrontendOptions.h

@@ -76,6 +76,9 @@ class FrontendOptions {
   /// binary module has already been built for use by the compiler.
   std::string PrebuiltModuleCachePath;
 
+  /// For these modules, we should prefer using Swift interface when importing them.
+  std::vector<std::string> PreferInterfaceForModules;
+
   /// Emit index data for imported serialized swift system modules.
   bool IndexSystemModules = false;
 

include/swift/Frontend/ParseableInterfaceModuleLoader.h

@@ -132,8 +132,9 @@ class ParseableInterfaceModuleLoader : public SerializedModuleLoaderBase {
   explicit ParseableInterfaceModuleLoader(
       ASTContext &ctx, StringRef cacheDir, StringRef prebuiltCacheDir,
       DependencyTracker *tracker, ModuleLoadingMode loadMode,
+      ArrayRef<std::string> PreferInterfaceForModules,
       bool RemarkOnRebuildFromInterface)
-  : SerializedModuleLoaderBase(ctx, tracker, loadMode),
+  : SerializedModuleLoaderBase(ctx, tracker, loadMode, PreferInterfaceForModules),
   CacheDir(cacheDir), PrebuiltCacheDir(prebuiltCacheDir),
   RemarkOnRebuildFromInterface(RemarkOnRebuildFromInterface)
   {}
@@ -154,10 +155,12 @@ class ParseableInterfaceModuleLoader : public SerializedModuleLoaderBase {
   static std::unique_ptr<ParseableInterfaceModuleLoader>
   create(ASTContext &ctx, StringRef cacheDir, StringRef prebuiltCacheDir,
          DependencyTracker *tracker, ModuleLoadingMode loadMode,
+         ArrayRef<std::string> PreferInterfaceForModules = {},
          bool RemarkOnRebuildFromInterface = false) {
     return std::unique_ptr<ParseableInterfaceModuleLoader>(
       new ParseableInterfaceModuleLoader(ctx, cacheDir, prebuiltCacheDir,
                                          tracker, loadMode,
+                                         PreferInterfaceForModules,
                                          RemarkOnRebuildFromInterface));
   }
 

include/swift/Serialization/SerializedModuleLoader.h

@@ -42,8 +42,10 @@ class SerializedModuleLoaderBase : public ModuleLoader {
 protected:
   ASTContext &Ctx;
   ModuleLoadingMode LoadMode;
+  ArrayRef<std::string> PreferInterfaceForModules;
   SerializedModuleLoaderBase(ASTContext &ctx, DependencyTracker *tracker,
-                             ModuleLoadingMode LoadMode);
+                             ModuleLoadingMode LoadMode,
+                             ArrayRef<std::string> PreferInterfaceForModules = {});
 
   void collectVisibleTopLevelModuleNamesImpl(SmallVectorImpl<Identifier> &names,
                                              StringRef extension) const;

lib/Frontend/Frontend.cpp

@@ -373,7 +373,8 @@ bool CompilerInstance::setUpModuleLoaders() {
     StringRef PrebuiltModuleCachePath = FEOpts.PrebuiltModuleCachePath;
     auto PIML = ParseableInterfaceModuleLoader::create(
         *Context, ModuleCachePath, PrebuiltModuleCachePath,
-        getDependencyTracker(), MLM, FEOpts.RemarkOnRebuildFromModuleInterface);
+        getDependencyTracker(), MLM, FEOpts.PreferInterfaceForModules,
+        FEOpts.RemarkOnRebuildFromModuleInterface);
     Context->addModuleLoader(std::move(PIML));
   }
   Context->addModuleLoader(std::move(SML));

lib/Frontend/ParseableInterfaceModuleLoader.cpp

@@ -1435,11 +1435,14 @@ std::error_code ParseableInterfaceModuleLoader::findModuleFilesInDirectory(
   }
 
   // Create an instance of the Impl to do the heavy lifting.
+  auto ModuleName = ModuleID.first.str();
   ParseableInterfaceModuleLoaderImpl Impl(
-                Ctx, ModPath, InPath, ModuleID.first.str(),
+                Ctx, ModPath, InPath, ModuleName,
                 CacheDir, PrebuiltCacheDir, ModuleID.second,
                 RemarkOnRebuildFromInterface, dependencyTracker,
-                LoadMode);
+                llvm::is_contained(PreferInterfaceForModules,
+                                   ModuleName)?
+                  ModuleLoadingMode::PreferParseable : LoadMode);
 
   // Ask the impl to find us a module that we can load or give us an error
   // telling us that we couldn't load it.

lib/Serialization/SerializedModuleLoader.cpp

@@ -104,8 +104,10 @@ Optional<bool> forEachModuleSearchPath(
 
 // Defined out-of-line so that we can see ~ModuleFile.
 SerializedModuleLoaderBase::SerializedModuleLoaderBase(
-    ASTContext &ctx, DependencyTracker *tracker, ModuleLoadingMode loadMode)
-    : ModuleLoader(tracker), Ctx(ctx), LoadMode(loadMode) {}
+    ASTContext &ctx, DependencyTracker *tracker, ModuleLoadingMode loadMode,
+    ArrayRef<std::string> PreferInterfaceForModules)
+    : ModuleLoader(tracker), Ctx(ctx), LoadMode(loadMode),
+      PreferInterfaceForModules(PreferInterfaceForModules) {}
 
 SerializedModuleLoaderBase::~SerializedModuleLoaderBase() = default;
 SerializedModuleLoader::~SerializedModuleLoader() = default;

test/api-digester/Outputs/Cake-interface-vs-binary.txt

@@ -0,0 +1,12 @@
+cake: Func FrozenKind.__derived_enum_equals(_:_:) has been removed
+cake: Accessor GlobalLetChangedToVar.Get() is a new API without @available attribute
+cake: Accessor GlobalVarChangedToLet.Get() is a new API without @available attribute
+cake: Accessor GlobalVarChangedToLet.Modify() is a new API without @available attribute
+cake: Accessor GlobalVarChangedToLet.Set() is a new API without @available attribute
+cake: Class C4 is now with @objc
+cake: Enum FrozenKind is now with @frozen
+cake: Enum IceKind is now with @frozen
+cake: Func FrozenKind.==(_:_:) is a new API without @available attribute
+cake: Var C1.CIIns1 is no longer a stored property
+cake: Var C1.CIIns2 is no longer a stored property
+cake: Var RemoveSetters.Value is no longer a stored property

test/api-digester/compare-dump-interface-vs-binary.swift

@@ -0,0 +1,23 @@
+// RUN: %empty-directory(%t.mod1)
+// RUN: %empty-directory(%t.mod2)
+// RUN: %empty-directory(%t.sdk)
+// RUN: %empty-directory(%t.module-cache)
+
+// Generate .swiftinterface file for module cake
+// RUN: %target-swift-frontend -typecheck -emit-parseable-module-interface-path %t.mod1/cake.swiftinterface %S/Inputs/cake_baseline/cake.swift -I %S/Inputs/APINotesLeft %clang-importer-sdk-nosource -parse-as-library -enable-library-evolution -disable-objc-attr-requires-foundation-module -module-cache-path %t.module-cache
+
+// Generate .swiftmodule file for module cake
+// RUN: %target-swift-frontend -emit-module -o %t.mod1/cake.swiftmodule %S/Inputs/cake_baseline/cake.swift -I %S/Inputs/APINotesLeft %clang-importer-sdk-nosource -parse-as-library  -disable-objc-attr-requires-foundation-module -module-cache-path %t.module-cache
+
+// Dump Json file for cake ABI via .swiftmodule file
+// RUN: %api-digester -dump-sdk -module cake -o - -module-cache-path %t.module-cache %clang-importer-sdk-nosource -I %t.mod1 -I %S/Inputs/APINotesLeft -abi > %t.dump1.json
+
+// Dump Json file for cake ABI via .swiftinteface file
+// RUN: %api-digester -dump-sdk -module cake -o - -module-cache-path %t.module-cache %clang-importer-sdk-nosource -I %t.mod1 -I %S/Inputs/APINotesLeft -abi -use-interface-for-module cake > %t.dump2.json
+
+// Compare two Json files and we should see some differences.
+// RUN: %api-digester -diagnose-sdk -print-module --input-paths %t.dump1.json -input-paths %t.dump2.json -abi -o %t.result
+
+// RUN: %clang -E -P -x c %S/Outputs/Cake-interface-vs-binary.txt -o - | sed '/^\s*$/d' > %t.expected
+// RUN: %clang -E -P -x c %t.result -o - | sed '/^\s*$/d' > %t.result.tmp
+// RUN: diff -u %t.expected %t.result.tmp

tools/swift-api-digester/swift-api-digester.cpp

@@ -229,6 +229,11 @@ static llvm::cl::opt<bool>
 Migrator("migrator",
          llvm::cl::desc("Dump Json suitable for generating migration script"),
          llvm::cl::cat(Category));
+
+static llvm::cl::list<std::string>
+PreferInterfaceForModules("use-interface-for-module", llvm::cl::ZeroOrMore,
+                          llvm::cl::desc("Prefer loading these modules via interface"),
+                          llvm::cl::cat(Category));
 } // namespace options
 
 namespace {
@@ -2431,6 +2436,9 @@ static int prepareForDump(const char *Main,
   for (auto M : options::ModuleNames) {
     Modules.insert(M);
   }
+  for (auto M: options::PreferInterfaceForModules) {
+    InitInvok.getFrontendOptions().PreferInterfaceForModules.push_back(M);
+  }
   if (Modules.empty()) {
     llvm::errs() << "Need to specify -include-all or -module <name>\n";
     exit(1);