[Dependency Scanning] Keep track of each imported module's access control

Adds an access control field for each imported module identified. When multiple imports of the same module are found, this keeps track of the most "open" access specifier.

Author: artemcm

include/swift/AST/ModuleDependencies.h

@@ -156,30 +156,35 @@ struct ScannerImportStatementInfo {
     uint32_t columnNumber;
   };
 
-  ScannerImportStatementInfo(std::string importIdentifier, bool isExported)
-      : importLocations(), importIdentifier(importIdentifier),
-        isExported(isExported) {}
+  ScannerImportStatementInfo(std::string importIdentifier, bool isExported,
+                             AccessLevel accessLevel)
+      : importIdentifier(importIdentifier), importLocations(),
+        isExported(isExported), accessLevel(accessLevel) {}
 
   ScannerImportStatementInfo(std::string importIdentifier, bool isExported,
+                             AccessLevel accessLevel,
                              ImportDiagnosticLocationInfo location)
-      : importLocations({location}), importIdentifier(importIdentifier),
-        isExported(isExported) {}
+      : importIdentifier(importIdentifier), importLocations({location}),
+        isExported(isExported), accessLevel(accessLevel) {}
 
   ScannerImportStatementInfo(std::string importIdentifier, bool isExported,
+                             AccessLevel accessLevel,
                              SmallVector<ImportDiagnosticLocationInfo, 4> locations)
-      : importLocations(locations), importIdentifier(importIdentifier),
-        isExported(isExported) {}
+      : importIdentifier(importIdentifier), importLocations(locations),
+        isExported(isExported), accessLevel(accessLevel) {}
 
   void addImportLocation(ImportDiagnosticLocationInfo location) {
     importLocations.push_back(location);
   }
 
-  /// Buffer, line & column number of the import statement
-  SmallVector<ImportDiagnosticLocationInfo, 4> importLocations;
   /// Imported module string. e.g. "Foo.Bar" in 'import Foo.Bar'
   std::string importIdentifier;
+  /// Buffer, line & column number of the import statement
+  SmallVector<ImportDiagnosticLocationInfo, 4> importLocations;
   /// Is this an @_exported import
   bool isExported;
+  /// Access level of this dependency
+  AccessLevel accessLevel;
 };
 
 /// Base class for the variant storage of ModuleDependencyInfo.
@@ -942,6 +947,7 @@ class ModuleDependencyInfo {
   /// Add a dependency on the given module, if it was not already in the set.
   void
   addOptionalModuleImport(StringRef module, bool isExported,
+                          AccessLevel accessLevel,
                           llvm::StringSet<> *alreadyAddedModules = nullptr);
 
   /// Add all of the module imports in the given source
@@ -952,12 +958,14 @@ class ModuleDependencyInfo {
 
   /// Add a dependency on the given module, if it was not already in the set.
   void addModuleImport(ImportPath::Module module, bool isExported,
+                       AccessLevel accessLevel,
                        llvm::StringSet<> *alreadyAddedModules = nullptr,
                        const SourceManager *sourceManager = nullptr,
                        SourceLoc sourceLocation = SourceLoc());
 
   /// Add a dependency on the given module, if it was not already in the set.
   void addModuleImport(StringRef module, bool isExported,
+                       AccessLevel accessLevel,
                        llvm::StringSet<> *alreadyAddedModules = nullptr,
                        const SourceManager *sourceManager = nullptr,
                        SourceLoc sourceLocation = SourceLoc());

include/swift/DependencyScan/SerializedModuleDependencyCacheFormat.h

@@ -67,6 +67,9 @@ using IsExportedImport = BCFixed<1>;
 using LineNumberField = BCFixed<32>;
 using ColumnNumberField = BCFixed<32>;
 
+/// Access level of an import
+using AccessLevelField = BCFixed<8>;
+
 /// Arrays of various identifiers, distinguished for readability
 using IdentifierIDArryField = llvm::BCArray<IdentifierIDField>;
 using ModuleIDArryField = llvm::BCArray<IdentifierIDField>;
@@ -192,7 +195,8 @@ using ImportStatementLayout =
                    LineNumberField,              // lineNumber
                    ColumnNumberField,            // columnNumber
                    IsOptionalImport,             // isOptional
-                   IsExportedImport              // isExported
+                   IsExportedImport,             // isExported
+                   AccessLevelField              // accessLevel
                    >;
 using ImportStatementArrayLayout =
     BCRecordLayout<IMPORT_STATEMENT_ARRAY_NODE, IdentifierIDArryField>;

include/swift/Serialization/SerializedModuleLoader.h

@@ -170,8 +170,7 @@ class SerializedModuleLoaderBase : public ModuleLoader {
                  bool isTestableImport, bool isCandidateForTextualModule);
 
   struct BinaryModuleImports {
-    llvm::StringSet<> moduleImports;
-    llvm::StringSet<> exportedModules;
+    std::vector<ScannerImportStatementInfo> moduleImports;
     std::string headerImport;
   };
 

lib/AST/ModuleDependencies.cpp

@@ -116,14 +116,34 @@ bool ModuleDependencyInfo::isTestableImport(StringRef moduleName) const {
 }
 
 void ModuleDependencyInfo::addOptionalModuleImport(
-    StringRef module, bool isExported, llvm::StringSet<> *alreadyAddedModules) {
-  if (!alreadyAddedModules || alreadyAddedModules->insert(module).second)
-    storage->optionalModuleImports.push_back({module.str(), isExported});
+    StringRef module, bool isExported, AccessLevel accessLevel,
+    llvm::StringSet<> *alreadyAddedModules) {
+
+  if (alreadyAddedModules && alreadyAddedModules->contains(module)) {
+    // Find a prior import of this module and add import location
+    // and adjust whether or not this module is ever imported as exported
+    // as well as the access level
+    for (auto &existingImport : storage->optionalModuleImports) {
+      if (existingImport.importIdentifier == module) {
+        existingImport.isExported |= isExported;
+        existingImport.accessLevel = std::max(existingImport.accessLevel,
+                                              accessLevel);
+        break;
+      }
+    }
+  } else {
+    if (alreadyAddedModules)
+      alreadyAddedModules->insert(module);
+
+    storage->optionalModuleImports.push_back(
+         {module.str(), isExported, accessLevel});
+  }
 }
 
 void ModuleDependencyInfo::addModuleImport(
-    StringRef module, bool isExported, llvm::StringSet<> *alreadyAddedModules,
-    const SourceManager *sourceManager, SourceLoc sourceLocation) {
+    StringRef module, bool isExported, AccessLevel accessLevel,
+    llvm::StringSet<> *alreadyAddedModules, const SourceManager *sourceManager,
+    SourceLoc sourceLocation) {
   auto scannerImportLocToDiagnosticLocInfo =
       [&sourceManager](SourceLoc sourceLocation) {
         auto lineAndColumnNumbers =
@@ -138,13 +158,16 @@ void ModuleDependencyInfo::addModuleImport(
   if (alreadyAddedModules && alreadyAddedModules->contains(module)) {
     // Find a prior import of this module and add import location
     // and adjust whether or not this module is ever imported as exported
+    // as well as the access level
     for (auto &existingImport : storage->moduleImports) {
       if (existingImport.importIdentifier == module) {
         if (validSourceLocation) {
           existingImport.addImportLocation(
-            scannerImportLocToDiagnosticLocInfo(sourceLocation));
+              scannerImportLocToDiagnosticLocInfo(sourceLocation));
         }
         existingImport.isExported |= isExported;
+        existingImport.accessLevel = std::max(existingImport.accessLevel,
+                                              accessLevel);
         break;
       }
     }
@@ -154,16 +177,18 @@ void ModuleDependencyInfo::addModuleImport(
 
     if (validSourceLocation)
       storage->moduleImports.push_back(ScannerImportStatementInfo(
-          module.str(), isExported, scannerImportLocToDiagnosticLocInfo(sourceLocation)));
+          module.str(), isExported, accessLevel,
+          scannerImportLocToDiagnosticLocInfo(sourceLocation)));
     else
       storage->moduleImports.push_back(
-         ScannerImportStatementInfo(module.str(), isExported));
+          ScannerImportStatementInfo(module.str(), isExported, accessLevel));
   }
 }
 
 void ModuleDependencyInfo::addModuleImport(
-    ImportPath::Module module, bool isExported, llvm::StringSet<> *alreadyAddedModules,
-    const SourceManager *sourceManager, SourceLoc sourceLocation) {
+    ImportPath::Module module, bool isExported, AccessLevel accessLevel,
+    llvm::StringSet<> *alreadyAddedModules, const SourceManager *sourceManager,
+    SourceLoc sourceLocation) {
   std::string ImportedModuleName = module.front().Item.str().str();
   auto submodulePath = module.getSubmodulePath();
   if (submodulePath.size() > 0 && !submodulePath[0].Item.empty()) {
@@ -172,11 +197,12 @@ void ModuleDependencyInfo::addModuleImport(
     // module named "Foo_Private". ClangImporter has special support for this.
     if (submoduleComponent.Item.str() == "Private")
       addOptionalModuleImport(ImportedModuleName + "_Private",
+                              isExported, accessLevel,
                               alreadyAddedModules);
   }
 
-  addModuleImport(ImportedModuleName, isExported, alreadyAddedModules,
-                  sourceManager, sourceLocation);
+  addModuleImport(ImportedModuleName, isExported, accessLevel,
+                  alreadyAddedModules, sourceManager, sourceLocation);
 }
 
 void ModuleDependencyInfo::addModuleImports(
@@ -205,6 +231,7 @@ void ModuleDependencyInfo::addModuleImports(
         continue;
 
       addModuleImport(realPath, importDecl->isExported(),
+                      importDecl->getAccessLevel(),
                       &alreadyAddedModules, sourceManager,
                       importDecl->getLoc());
 

lib/ClangImporter/ClangModuleDependencyScanner.cpp

@@ -191,7 +191,8 @@ ModuleDependencyVector ClangImporter::bridgeClangModuleDependencies(
       // FIXME: This assumes, conservatively, that all Clang module imports
       // are exported. We need to fix this once the clang scanner gains the appropriate
       // API to query this.
-      dependencies.addModuleImport(moduleName.ModuleName, /* isExported */ true, &alreadyAddedModules);
+      dependencies.addModuleImport(moduleName.ModuleName, /* isExported */ true,
+                                   AccessLevel::Public, &alreadyAddedModules);
       // It is safe to assume that all dependencies of a Clang module are Clang modules.
       directDependencyIDs.push_back({moduleName.ModuleName, ModuleDependencyKind::Clang});
     }

lib/DependencyScan/ModuleDependencyCacheSerialization.cpp

@@ -415,9 +415,11 @@ bool ModuleDependenciesCacheDeserializer::readGraph(
       unsigned importIdentifierID, bufferIdentifierID;
       unsigned lineNumber, columnNumber;
       bool isOptional, isExported;
+      uint8_t rawAccessLevel;
       ImportStatementLayout::readRecord(Scratch, importIdentifierID,
                                         bufferIdentifierID, lineNumber,
-                                        columnNumber, isOptional, isExported);
+                                        columnNumber, isOptional, isExported,
+                                        rawAccessLevel);
       auto importIdentifier = getIdentifier(importIdentifierID);
       if (!importIdentifier)
         llvm::report_fatal_error("Bad import statement info: no import name");
@@ -428,10 +430,10 @@ bool ModuleDependenciesCacheDeserializer::readGraph(
             "Bad import statement info: no buffer identifier");
       if (bufferIdentifier->empty())
         ImportStatements.push_back(ScannerImportStatementInfo(
-            *importIdentifier, isExported));
+            *importIdentifier, isExported, AccessLevel(rawAccessLevel)));
       else
         ImportStatements.push_back(ScannerImportStatementInfo(
-            *importIdentifier, isExported,
+            *importIdentifier, isExported, AccessLevel(rawAccessLevel),
             ScannerImportStatementInfo::ImportDiagnosticLocationInfo(
                 *bufferIdentifier, lineNumber, columnNumber)));
       break;
@@ -1527,15 +1529,17 @@ unsigned ModuleDependenciesCacheSerializer::writeImportStatementInfos(
       ImportStatementLayout::emitRecord(
           Out, ScratchRecord, AbbrCodes[ImportStatementLayout::Code],
           getIdentifier(importInfo.importIdentifier),
-          0, 0, 0, isOptional, importInfo.isExported);
+          0, 0, 0, isOptional, importInfo.isExported,
+          static_cast<std::underlying_type<AccessLevel>::type>(importInfo.accessLevel));
       count++;
     } else {
       for (auto &importLoc : importInfo.importLocations) {
         ImportStatementLayout::emitRecord(
             Out, ScratchRecord, AbbrCodes[ImportStatementLayout::Code],
             getIdentifier(importInfo.importIdentifier),
             getIdentifier(importLoc.bufferIdentifier), importLoc.lineNumber,
-            importLoc.columnNumber, isOptional, importInfo.isExported);
+            importLoc.columnNumber, isOptional, importInfo.isExported,
+            static_cast<std::underlying_type<AccessLevel>::type>(importInfo.accessLevel));
         count++;
       }
     }

lib/DependencyScan/ModuleDependencyScanner.cpp

@@ -544,6 +544,7 @@ ModuleDependencyScanner::getMainModuleDependencyInfo(ModuleDecl *mainModule) {
 
     case ImplicitStdlibKind::Stdlib:
       mainDependencies.addModuleImport("Swift", /* isExported */false,
+                                       AccessLevel::Public,
                                        &alreadyAddedModules);
       break;
     }
@@ -552,6 +553,7 @@ ModuleDependencyScanner::getMainModuleDependencyInfo(ModuleDecl *mainModule) {
     for (const auto &import : importInfo.AdditionalUnloadedImports) {
       mainDependencies.addModuleImport(import.module.getModulePath(),
                                        import.options.contains(ImportFlags::Exported),
+                                       import.accessLevel,
                                        &alreadyAddedModules,
                                        &ScanASTContext.SourceMgr);
     }
@@ -561,6 +563,7 @@ ModuleDependencyScanner::getMainModuleDependencyInfo(ModuleDecl *mainModule) {
       mainDependencies.addModuleImport(
           import.module.importedModule->getNameStr(),
           import.options.contains(ImportFlags::Exported),
+          import.accessLevel,
           &alreadyAddedModules);
     }
 
@@ -574,6 +577,7 @@ ModuleDependencyScanner::getMainModuleDependencyInfo(ModuleDecl *mainModule) {
     if (importInfo.ShouldImportUnderlyingModule) {
       mainDependencies.addModuleImport(mainModule->getName().str(),
                                        /* isExported */ true,
+                                       AccessLevel::Public,
                                        &alreadyAddedModules);
     }
 
@@ -584,6 +588,7 @@ ModuleDependencyScanner::getMainModuleDependencyInfo(ModuleDecl *mainModule) {
          ScanCompilerInvocation.getTBDGenOptions().embedSymbolsFromModules) {
       mainDependencies.addModuleImport(tbdSymbolModule,
                                        /* isExported */ false,
+                                       AccessLevel::Public,
                                        &alreadyAddedModules);
     }
   }
@@ -948,7 +953,8 @@ void ModuleDependencyScanner::resolveAllClangModuleDependencies(
             if (importInfo.importIdentifier ==
                 ScanASTContext.Id_CxxStdlib.str()) {
               auto canonicalImportInfo = ScannerImportStatementInfo(
-                  "std", importInfo.isExported, importInfo.importLocations);
+                  "std", importInfo.isExported, importInfo.accessLevel,
+                  importInfo.importLocations);
               unresolvedImports.push_back(canonicalImportInfo);
               unresolvedImportIdentifiers.insert(
                   canonicalImportInfo.importIdentifier);
@@ -1475,7 +1481,9 @@ void ModuleDependencyScanner::resolveCrossImportOverlayDependencies(
   std::for_each(newOverlays.begin(), newOverlays.end(),
                 [&](Identifier modName) {
                   dummyMainDependencies.addModuleImport(modName.str(),
-                                                        /* isExported */ false);
+                                                        /* isExported */ false,
+                                                        // TODO: What is the right access level for a cross-import overlay?
+                                                        AccessLevel::Public);
                 });
 
   // Record the dummy main module's direct dependencies. The dummy main module

lib/Serialization/ScanningLoaders.cpp

@@ -242,6 +242,7 @@ SwiftModuleScanner::scanInterfaceFile(Twine moduleInterfacePath,
         for (auto import : imInfo.AdditionalUnloadedImports) {
           Result->addModuleImport(import.module.getModulePath(),
                                   import.options.contains(ImportFlags::Exported),
+                                  import.accessLevel,
                                   &alreadyAddedModules, &Ctx.SourceMgr);
         }
 
@@ -270,6 +271,7 @@ SwiftModuleScanner::scanInterfaceFile(Twine moduleInterfacePath,
                if (!alreadyAddedModules.contains(requiredImport.importIdentifier))
                  Result->addModuleImport(requiredImport.importIdentifier,
                                          requiredImport.isExported,
+                                         requiredImport.accessLevel,
                                          &alreadyAddedModules);
            }
          }