[Serialization] Add control over adding a loaded module to the in-memory cache

Author: xymus

include/swift/AST/ModuleLoader.h

@@ -249,10 +249,14 @@ class ModuleLoader {
   /// \param path A sequence of (identifier, location) pairs that denote
   /// the dotted module name to load, e.g., AppKit.NSWindow.
   ///
+  /// \param AllowMemoryCache Enables preserving the loaded module in the
+  /// in-memory cache for the next loading attempt.
+  ///
   /// \returns the module referenced, if it could be loaded. Otherwise,
   /// emits a diagnostic and returns NULL.
   virtual
-  ModuleDecl *loadModule(SourceLoc importLoc, ImportPath::Module path) = 0;
+  ModuleDecl *loadModule(SourceLoc importLoc, ImportPath::Module path,
+                         bool AllowMemoryCache = true) = 0;
 
   /// Load extensions to the given nominal type.
   ///

include/swift/ClangImporter/ClangImporter.h

@@ -220,11 +220,15 @@ class ClangImporter final : public ClangModuleLoader {
   /// \param path A sequence of (identifier, location) pairs that denote
   /// the dotted module name to load, e.g., AppKit.NSWindow.
   ///
+  /// \param AllowMemoryCache Enables preserving the loaded module in the
+  /// in-memory cache for the next loading attempt.
+  ///
   /// \returns the module referenced, if it could be loaded. Otherwise,
   /// emits a diagnostic and returns NULL.
   virtual ModuleDecl *loadModule(
                         SourceLoc importLoc,
-                        ImportPath::Module path)
+                        ImportPath::Module path,
+                        bool AllowMemoryCache = true)
                       override;
 
   /// Determine whether \c overlayDC is within an overlay module for the

include/swift/Sema/SourceLoader.h

@@ -73,7 +73,8 @@ class SourceLoader : public ModuleLoader {
   /// returns NULL.
   virtual ModuleDecl *
   loadModule(SourceLoc importLoc,
-             ImportPath::Module path) override;
+             ImportPath::Module path,
+             bool AllowMemoryCache) override;
 
   /// Load extensions to the given nominal type.
   ///

include/swift/Serialization/SerializedModuleLoader.h

@@ -185,7 +185,8 @@ class SerializedModuleLoaderBase : public ModuleLoader {
   /// emits a diagnostic and returns a FailedImportModule object.
   virtual ModuleDecl *
   loadModule(SourceLoc importLoc,
-             ImportPath::Module path) override;
+             ImportPath::Module path,
+             bool AllowMemoryCache) override;
 
 
   virtual void loadExtensions(NominalTypeDecl *nominal,
@@ -294,7 +295,8 @@ class MemoryBufferSerializedModuleLoader : public SerializedModuleLoaderBase {
 
   ModuleDecl *
   loadModule(SourceLoc importLoc,
-             ImportPath::Module path) override;
+             ImportPath::Module path,
+             bool AllowMemoryCache = true) override;
 
   /// Register a memory buffer that contains the serialized module for the given
   /// access path. This API is intended to be used by LLDB to add swiftmodules

lib/AST/ASTContext.cpp

@@ -2456,7 +2456,8 @@ ASTContext::getModule(ImportPath::Module ModulePath, bool AllowMemoryCached) {
   if (PreModuleImportCallback)
     PreModuleImportCallback(moduleID.Item.str(), false /*=IsOverlay*/);
   for (auto &importer : getImpl().ModuleLoaders) {
-    if (ModuleDecl *M = importer->loadModule(moduleID.Loc, ModulePath)) {
+    if (ModuleDecl *M = importer->loadModule(moduleID.Loc, ModulePath,
+                                             AllowMemoryCached)) {
       if (LangOpts.EnableModuleLoadingRemarks) {
         Diags.diagnose(ModulePath.getSourceRange().Start,
                        diag::module_loaded,

lib/ClangImporter/ClangImporter.cpp

@@ -2018,7 +2018,8 @@ ModuleDecl *ClangImporter::Implementation::loadModuleClang(
 
 ModuleDecl *
 ClangImporter::loadModule(SourceLoc importLoc,
-                          ImportPath::Module path) {
+                          ImportPath::Module path,
+                          bool AllowMemoryCache) {
   return Impl.loadModule(importLoc, path);
 }
 

lib/Sema/SourceLoader.cpp

@@ -94,7 +94,8 @@ bool SourceLoader::canImportModule(ImportPath::Module path,
 }
 
 ModuleDecl *SourceLoader::loadModule(SourceLoc importLoc,
-                                     ImportPath::Module path) {
+                                     ImportPath::Module path,
+                                     bool AllowMemoryCache) {
   // FIXME: Swift submodules?
   if (path.size() > 1)
     return nullptr;

lib/Serialization/SerializedModuleLoader.cpp

@@ -1208,7 +1208,8 @@ bool MemoryBufferSerializedModuleLoader::canImportModule(
 
 ModuleDecl *
 SerializedModuleLoaderBase::loadModule(SourceLoc importLoc,
-                                       ImportPath::Module path) {
+                                       ImportPath::Module path,
+                                       bool AllowMemoryCache) {
   // FIXME: Swift submodules?
   if (path.size() > 1)
     return nullptr;
@@ -1233,7 +1234,8 @@ SerializedModuleLoaderBase::loadModule(SourceLoc importLoc,
 
   auto M = ModuleDecl::create(moduleID.Item, Ctx);
   M->setIsSystemModule(isSystemModule);
-  Ctx.addLoadedModule(M);
+  if (AllowMemoryCache)
+    Ctx.addLoadedModule(M);
   SWIFT_DEFER { M->setHasResolvedImports(); };
 
   llvm::sys::path::native(moduleInterfacePath);
@@ -1264,7 +1266,8 @@ SerializedModuleLoaderBase::loadModule(SourceLoc importLoc,
 
 ModuleDecl *
 MemoryBufferSerializedModuleLoader::loadModule(SourceLoc importLoc,
-                                               ImportPath::Module path) {
+                                               ImportPath::Module path,
+                                               bool AllowMemoryCache) {
   // FIXME: Swift submodules?
   if (path.size() > 1)
     return nullptr;
@@ -1300,7 +1303,8 @@ MemoryBufferSerializedModuleLoader::loadModule(SourceLoc importLoc,
   if (BypassResilience)
     M->setBypassResilience();
   M->addFile(*file);
-  Ctx.addLoadedModule(M);
+  if (AllowMemoryCache)
+    Ctx.addLoadedModule(M);
   return M;
 }