Disable prelude import in language-server tests. (#7489)

This was substantially slowing down the overall test suite.

Fixes #7453

Assisted-by: Gemini via Antigravity

toolchain/driver/language_server_subcommand.cpp

@@ -19,6 +19,21 @@ Runs the language server.
 LanguageServerSubcommand::LanguageServerSubcommand()
     : DriverSubcommand(SubcommandInfo) {}
 
+auto LanguageServerSubcommand::BuildOptions(CommandLine::CommandBuilder& b)
+    -> void {
+  b.AddFlag(
+      {
+          .name = "prelude-import",
+          .help = R"""(
+Whether to use the implicit prelude import. Enabled by default.
+)""",
+      },
+      [&](auto& arg_b) {
+        arg_b.Default(true);
+        arg_b.Set(&prelude_import_);
+      });
+}
+
 auto LanguageServerSubcommand::Run(DriverEnv& driver_env) -> DriverResult {
   if (!driver_env.input_stream) {
     CARBON_DIAGNOSTIC(LanguageServerMissingInputStream, Error,
@@ -27,10 +42,10 @@ auto LanguageServerSubcommand::Run(DriverEnv& driver_env) -> DriverResult {
     return {.success = false};
   }
 
-  bool success =
-      LanguageServer::Run(*driver_env.installation, driver_env.input_stream,
-                          *driver_env.output_stream, *driver_env.error_stream,
-                          driver_env.vlog_stream, *driver_env.consumer);
+  bool success = LanguageServer::Run(
+      *driver_env.installation, driver_env.input_stream,
+      *driver_env.output_stream, *driver_env.error_stream,
+      driver_env.vlog_stream, *driver_env.consumer, prelude_import_);
   return {.success = success};
 }
 

toolchain/driver/language_server_subcommand.h

@@ -14,14 +14,17 @@
 
 namespace Carbon {
 
-// Implements the link subcommand of the driver.
+// Implements the language-server subcommand of the driver.
 class LanguageServerSubcommand : public DriverSubcommand {
  public:
   explicit LanguageServerSubcommand();
 
-  auto BuildOptions(CommandLine::CommandBuilder& /*b*/) -> void override {}
+  auto BuildOptions(CommandLine::CommandBuilder& b) -> void override;
 
   auto Run(DriverEnv& driver_env) -> DriverResult override;
+
+ private:
+  bool prelude_import_ = true;
 };
 
 }  // namespace Carbon

toolchain/language_server/context.cpp

@@ -190,12 +190,14 @@ class VirtualFileSystem : public llvm::vfs::FileSystem {
 Context::Context(const InstallPaths* installation,
                  llvm::raw_ostream* vlog_stream,
                  Diagnostics::Consumer* consumer,
-                 clang::clangd::LSPBinder::RawOutgoing* outgoing)
+                 clang::clangd::LSPBinder::RawOutgoing* outgoing,
+                 bool prelude_import)
     : installation_(installation),
       vlog_stream_(vlog_stream),
       file_emitter_(consumer),
       no_loc_emitter_(consumer),
-      outgoing_(outgoing) {
+      outgoing_(outgoing),
+      prelude_import_(prelude_import) {
   auto ls_fs = llvm::makeIntrusiveRefCnt<VirtualFileSystem>(this);
   auto vfs = llvm::makeIntrusiveRefCnt<llvm::vfs::OverlayFileSystem>(
       llvm::vfs::getRealFileSystem());
@@ -229,8 +231,8 @@ auto Context::File::SetText(Context& context, std::optional<int64_t> version,
   options_ = CompileOptions();
   options_.codegen_options->target = options_.codegen_options->host;
   options_.phase = CompileOptions::Phase::Check;
+  options_.prelude_import = context.prelude_import();
   options_.input_filenames.push_back(filename());
-  options_.prelude_import = true;
 
   compile_driver_ = std::make_unique<CompileDriver>(&options_);
   auto map_input = [](llvm::StringRef) -> std::string { return ""; };

toolchain/language_server/context.h

@@ -59,7 +59,8 @@ class Context {
   explicit Context(const InstallPaths* installation,
                    llvm::raw_ostream* vlog_stream,
                    Diagnostics::Consumer* consumer,
-                   clang::clangd::LSPBinder::RawOutgoing* outgoing);
+                   clang::clangd::LSPBinder::RawOutgoing* outgoing,
+                   bool prelude_import);
 
   // Returns the virtual filesystem.
   auto vfs() -> llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem>& {
@@ -86,6 +87,8 @@ class Context {
 
   auto files() -> Map<std::string, File>& { return files_; }
 
+  auto prelude_import() const -> bool { return prelude_import_; }
+
  private:
   const InstallPaths* installation_;
 
@@ -100,6 +103,8 @@ class Context {
 
   // Content of files managed by the language client.
   Map<std::string, File> files_;
+
+  bool prelude_import_;
 };
 
 }  // namespace Carbon::LanguageServer

toolchain/language_server/language_server.cpp

@@ -46,8 +46,8 @@ class Logger : public clang::clangd::Logger {
 
 auto Run(const InstallPaths& installation, FILE* input_stream,
          llvm::raw_ostream& output_stream, llvm::raw_ostream& error_stream,
-         llvm::raw_ostream* vlog_stream, Diagnostics::Consumer& consumer)
-    -> bool {
+         llvm::raw_ostream* vlog_stream, Diagnostics::Consumer& consumer,
+         bool prelude_import) -> bool {
   // The language server internally uses diagnostics for logging issues, but the
   // clangd parts have their own logging system. We intercept that here.
   Logger logger(&error_stream, vlog_stream);
@@ -59,7 +59,8 @@ auto Run(const InstallPaths& installation, FILE* input_stream,
                                       /*InMirror=*/nullptr,
                                       /*Pretty=*/true));
   OutgoingMessages outgoing(transport.get());
-  Context context(&installation, vlog_stream, &consumer, &outgoing);
+  Context context(&installation, vlog_stream, &consumer, &outgoing,
+                  prelude_import);
   IncomingMessages incoming(transport.get(), &context);
 
   // Run the server loop.

toolchain/language_server/language_server.h

@@ -18,8 +18,8 @@ namespace Carbon::LanguageServer {
 // This is thread-hostile because `clangd::LoggingSession` relies on a global.
 auto Run(const InstallPaths& installation, FILE* input_stream,
          llvm::raw_ostream& output_stream, llvm::raw_ostream& error_stream,
-         llvm::raw_ostream* vlog_stream, Diagnostics::Consumer& consumer)
-    -> bool;
+         llvm::raw_ostream* vlog_stream, Diagnostics::Consumer& consumer,
+         bool prelude_import) -> bool;
 
 }  // namespace Carbon::LanguageServer
 

toolchain/language_server/testdata/text_document/import_prelude.carbon

@@ -2,6 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --prelude-import
+//
 // AUTOUPDATE
 // TIP: To test this file alone, run:
 // TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/language_server/testdata/text_document/import_prelude.carbon

toolchain/testing/file_test.cpp

@@ -244,7 +244,7 @@ auto ToolchainFileTest::GetDefaultArgs() const
     args.insert(args.end(), {"format", "%s"});
     return args;
   } else if (component_ == "language_server") {
-    args.insert(args.end(), {"language-server"});
+    args.insert(args.end(), {"language-server", "--no-prelude-import"});
     return args;
   }