[lldb] Make swift::ASTContext accesses thread safe

swift::ASTContext is not thread safe by default, wrap SwiftASTContext's
swift::ASTContext in a LockGuarded.

rdar://121409294

Author: augusto2112

lldb/source/Plugins/ExpressionParser/Swift/SwiftExpressionParser.cpp

@@ -792,7 +792,7 @@ static void ResolveSpecialNames(
 
 /// Initialize the SwiftASTContext and return the wrapped
 /// swift::ASTContext when successful.
-static swift::ASTContext *
+static ThreadSafeASTContext
 SetupASTContext(SwiftASTContextForExpressions &swift_ast_context,
                 DiagnosticManager &diagnostic_manager,
                 std::function<bool()> disable_objc_runtime, bool repl,
@@ -806,27 +806,27 @@ SetupASTContext(SwiftASTContextForExpressions &swift_ast_context,
     diagnostic_manager.PutString(eSeverityInfo,
                                  "Couldn't initialize Swift expression "
                                  "evaluator due to previous errors.");
-    return nullptr;
+    return ThreadSafeASTContext();
   }
 
   if (swift_ast_context.HasFatalErrors()) {
     diagnostic_manager.PutString(eSeverityError,
                                  "The AST context is in a fatal error state.");
-    return nullptr;
+    return ThreadSafeASTContext();
   }
 
-  swift::ASTContext *ast_context = swift_ast_context.GetASTContext();
+  ThreadSafeASTContext ast_context = swift_ast_context.GetASTContext();
   if (!ast_context) {
     diagnostic_manager.PutString(
         eSeverityError,
         "Couldn't initialize the AST context.  Please check your settings.");
-    return nullptr;
+    return ThreadSafeASTContext();
   }
 
   if (swift_ast_context.HasFatalErrors()) {
     diagnostic_manager.PutString(eSeverityError,
                                  "The AST context is in a fatal error state.");
-    return nullptr;
+    return ThreadSafeASTContext();
   }
 
   // TODO: Find a way to get contraint-solver output sent to a stream
@@ -1126,7 +1126,7 @@ char ModuleImportError::ID = 0;
 /// This holds the result of ParseAndImport.
 struct ParsedExpression {
   std::unique_ptr<SwiftASTManipulator> code_manipulator;
-  swift::ASTContext &ast_context;
+  ThreadSafeASTContext ast_context;
   swift::ModuleDecl &module;
   LLDBNameLookup &external_lookup;
   swift::SourceFile &source_file;
@@ -1293,7 +1293,7 @@ static llvm::Expected<ParsedExpression> ParseAndImport(
     return !ObjCLanguageRuntime::Get(*process_sp);
   };
 
-  swift::ASTContext *ast_context =
+  ThreadSafeASTContext ast_context =
       SetupASTContext(swift_ast_context, diagnostic_manager,
                       should_disable_objc_runtime, repl, playground);
   if (!ast_context)
@@ -1352,7 +1352,7 @@ static llvm::Expected<ParsedExpression> ParseAndImport(
     importInfo.AdditionalImports.emplace_back(attributed_import);
 
   auto module_id = ast_context->getIdentifier(expr_name_buf);
-  auto &module = *swift::ModuleDecl::create(module_id, *ast_context,
+  auto &module = *swift::ModuleDecl::create(module_id, **ast_context,
                                             importInfo);
 
   swift::SourceFileKind source_file_kind = swift::SourceFileKind::Library;
@@ -1362,7 +1362,7 @@ static llvm::Expected<ParsedExpression> ParseAndImport(
 
   // Create the source file. Note, we disable delayed parsing for the
   // swift expression parser.
-  swift::SourceFile *source_file = new (*ast_context)
+  swift::SourceFile *source_file = new (**ast_context)
       swift::SourceFile(module, source_file_kind, buffer_id,
                         swift::SourceFile::ParsingFlags::DisableDelayedBodies);
   module.addFile(*source_file);
@@ -1520,8 +1520,13 @@ static llvm::Expected<ParsedExpression> ParseAndImport(
   swift::verify(*source_file);
 
   ParsedExpression result = {
-    std::move(code_manipulator), *ast_context, module, *external_lookup,
-    *source_file, std::move(main_filename), /*buffer_id*/0,
+      std::move(code_manipulator),
+      std::move(ast_context),
+      module,
+      *external_lookup,
+      *source_file,
+      std::move(main_filename),
+      /*buffer_id*/ 0,
   };
   return std::move(result);
 }
@@ -2140,7 +2145,7 @@ SwiftExpressionParser::Parse(DiagnosticManager &diagnostic_manager,
   // part of the parse from the staging area in the external lookup
   // object into the SwiftPersistentExpressionState.
   swift::ModuleDecl *module = &parsed_expr->module;
-  parsed_expr->ast_context.addLoadedModule(module);
+  parsed_expr->ast_context->addLoadedModule(module);
   m_swift_ast_ctx.CacheModule(module);
   if (m_sc.target_sp) {
     auto *persistent_state =

lldb/source/Plugins/ExpressionParser/Swift/SwiftREPL.cpp

@@ -574,7 +574,7 @@ void SwiftREPL::CompleteCode(const std::string &current_code,
   SwiftASTContextForExpressions *swift_ast = m_swift_ast;
 
   if (swift_ast) {
-    swift::ASTContext *ast = swift_ast->GetASTContext();
+    ThreadSafeASTContext ast = swift_ast->GetASTContext();
     swift::REPLCompletions completions;
     SourceModule completion_module_info;
     completion_module_info.path.push_back(ConstString("repl"));
@@ -587,7 +587,7 @@ void SwiftREPL::CompleteCode(const std::string &current_code,
       repl_module = swift_ast->CreateModule(completion_module_info, error,
                                             importInfo);
       std::optional<unsigned> bufferID;
-      swift::SourceFile *repl_source_file = new (*ast) swift::SourceFile(
+      swift::SourceFile *repl_source_file = new (**ast) swift::SourceFile(
           *repl_module, swift::SourceFileKind::Main, bufferID);
       repl_module->addFile(*repl_source_file);
       swift::performImportResolution(*repl_source_file);

lldb/source/Plugins/ExpressionParser/Swift/SwiftUserExpression.cpp

@@ -378,7 +378,7 @@ static llvm::Error AddVariableInfo(
       ss.flush();
       log->Printf("Adding injected self: type (%p) context(%p) is: %s",
                   static_cast<void *>(swift_type.getPointer()),
-                  static_cast<void *>(ast_context.GetASTContext()), s.c_str());
+                  static_cast<void *>(*ast_context.GetASTContext()), s.c_str());
     }
   // A one-off clone of variable_sp with the type replaced by target_type.
   auto patched_variable_sp = std::make_shared<lldb_private::Variable>(

lldb/source/Plugins/InstrumentationRuntime/MainThreadChecker/InstrumentationRuntimeMainThreadChecker.cpp

@@ -150,7 +150,8 @@ static std::string TranslateObjCNameToSwiftName(std::string className,
     }
   };
 
-  MyConsumer consumer(swift::ObjCSelector(*ctx->GetASTContext(), numArguments,
+  ThreadSafeASTContext ast_ctx = ctx->GetASTContext();
+  MyConsumer consumer(swift::ObjCSelector(**ast_ctx, numArguments,
                                           selectorIdentifiers));
   // FIXME(mracek): Switch to a new API that translates the Clang class name
   // to Swift class name, once this API exists. Now we assume they are the same.

lldb/source/Plugins/LanguageRuntime/Swift/SwiftLanguageRuntimeRemoteAST.cpp

@@ -59,17 +59,18 @@ swift::remoteAST::RemoteASTContext &
 SwiftLanguageRuntimeImpl::GetRemoteASTContext(SwiftASTContext &swift_ast_ctx) {
   // If we already have a remote AST context for this AST context,
   // return it.
-  auto known = m_remote_ast_contexts.find(swift_ast_ctx.GetASTContext());
+  ThreadSafeASTContext ast_ctx = swift_ast_ctx.GetASTContext();
+  auto known = m_remote_ast_contexts.find(*ast_ctx);
   if (known != m_remote_ast_contexts.end())
     return *known->second;
 
   // Initialize a new remote AST context.
   (void)GetReflectionContext();
   auto remote_ast_up = std::make_unique<swift::remoteAST::RemoteASTContext>(
-      *swift_ast_ctx.GetASTContext(), GetMemoryReader());
+      **ast_ctx, GetMemoryReader());
   auto &remote_ast = *remote_ast_up;
   m_remote_ast_contexts.insert(
-      {swift_ast_ctx.GetASTContext(), std::move(remote_ast_up)});
+      {*ast_ctx, std::move(remote_ast_up)});
   return remote_ast;
 }
 
@@ -521,7 +522,8 @@ SwiftLanguageRuntimeImpl::GetMetadataPromise(const SymbolContext *sc,
   if (addr == 0 || addr == LLDB_INVALID_ADDRESS)
     return nullptr;
 
-  auto key = std::make_pair(swift_ast_ctx->GetASTContext(), addr);
+  ThreadSafeASTContext ast_ctx = swift_ast_ctx->GetASTContext();
+  auto key = std::make_pair(*ast_ctx, addr);
   auto iter = m_promises_map.find(key);
   if (iter != m_promises_map.end())
     return iter->second;