Stop emitting .swiftsourceinfo if not explicitly requested

swift/internal/feature_names.bzl

@@ -308,8 +308,8 @@ SWIFT_FEATURE_EMIT_PRIVATE_SWIFTINTERFACE = "swift.emit_private_swiftinterface"
 # any of the existing compiler flags. Only enable this feature if such
 # non-determinism does not negatively impact you.
 #
-# Note: If opted out of this feature, .swiftsourceinfo are generated by the
-# compiler but excluded from Bazel's tracking.
+# If opted out of this feature, the compiler is instructed not to generate a
+# `.swiftsourceinfo` file.
 SWIFT_FEATURE_DECLARE_SWIFTSOURCEINFO = "swift.emit_swiftsourceinfo"
 
 # If enabled, the .swiftmodule file for the affected target will not be

swift/toolchains/config/compile_config.bzl

@@ -580,22 +580,10 @@ def compile_action_configs(
             ],
             not_features = [SWIFT_FEATURE_COVERAGE_PREFIX_MAP, SWIFT_FEATURE_FILE_PREFIX_MAP],
         ),
-
-        # Ensure that .swiftsourceinfo files are tracked and not deleted by the worker
         ActionConfigInfo(
-            actions = [
-                SWIFT_ACTION_COMPILE,
-            ],
-            configurators = [add_arg("-Xwrapped-swift=-emit-swiftsourceinfo")],
-            features = [SWIFT_FEATURE_DECLARE_SWIFTSOURCEINFO],
-            not_features = [SWIFT_FEATURE_SPLIT_DERIVED_FILES_GENERATION],
-        ),
-        ActionConfigInfo(
-            actions = [
-                SWIFT_ACTION_DERIVE_FILES,
-            ],
-            configurators = [add_arg("-Xwrapped-swift=-emit-swiftsourceinfo")],
-            features = [SWIFT_FEATURE_DECLARE_SWIFTSOURCEINFO],
+            actions = all_compile_action_names(),
+            configurators = [add_arg("-avoid-emit-module-source-info")],
+            not_features = [SWIFT_FEATURE_DECLARE_SWIFTSOURCEINFO],
         ),
     ]
 

test/split_derived_files_tests.bzl

@@ -25,6 +25,14 @@ default_no_split_emit_swiftsourceinfo_provider_test = make_provider_test_rule(
     },
 )
 
+default_no_split_emit_swiftsourceinfo_test = make_action_command_line_test_rule(
+    config_settings = {
+        "//command_line_option:features": [
+            "swift.emit_swiftsourceinfo",
+        ],
+    },
+)
+
 split_swiftmodule_test = make_action_command_line_test_rule(
     config_settings = {
         "//command_line_option:features": [
@@ -61,6 +69,15 @@ split_emit_swiftsourceinfo_provider_test = make_provider_test_rule(
     },
 )
 
+split_emit_swiftsourceinfo_test = make_action_command_line_test_rule(
+    config_settings = {
+        "//command_line_option:features": [
+            "swift.emit_swiftsourceinfo",
+            "swift.split_derived_files_generation",
+        ],
+    },
+)
+
 split_no_emit_swiftdoc_provider_test = make_provider_test_rule(
     config_settings = {
         "//command_line_option:features": [
@@ -135,6 +152,7 @@ def split_derived_files_test_suite(name, tags = []):
     default_no_split_test(
         name = "{}_default_no_split_args".format(name),
         expected_argv = [
+            "-avoid-emit-module-source-info",
             "-emit-module-path",
             "-emit-object",
             "-enable-batch-mode",
@@ -148,6 +166,16 @@ def split_derived_files_test_suite(name, tags = []):
         target_under_test = "//test/fixtures/debug_settings:simple",
     )
 
+    default_no_split_emit_swiftsourceinfo_test(
+        name = "{}_default_no_split_emit_swiftsourceinfo_args".format(name),
+        mnemonic = "SwiftCompile",
+        not_expected_argv = [
+            "-avoid-emit-module-source-info",
+        ],
+        tags = all_tags,
+        target_under_test = "//test/fixtures/debug_settings:simple",
+    )
+
     default_no_split_provider_test(
         name = "{}_default_no_split_provider_swiftmodule".format(name),
         expected_files = [
@@ -274,6 +302,7 @@ def split_derived_files_test_suite(name, tags = []):
     split_swiftmodule_test(
         name = "{}_object_only".format(name),
         expected_argv = [
+            "-avoid-emit-module-source-info",
             "-emit-object",
             "-enable-batch-mode",
             "simple.output_file_map.json",
@@ -290,6 +319,7 @@ def split_derived_files_test_suite(name, tags = []):
     split_swiftmodule_test(
         name = "{}_swiftmodule_only".format(name),
         expected_argv = [
+            "-avoid-emit-module-source-info",
             "-emit-module-path",
             "-enable-batch-mode",
             "simple.derived_output_file_map.json",
@@ -303,6 +333,26 @@ def split_derived_files_test_suite(name, tags = []):
         target_under_test = "//test/fixtures/debug_settings:simple",
     )
 
+    split_emit_swiftsourceinfo_test(
+        name = "{}_object_only_emit_swiftsourceinfo".format(name),
+        mnemonic = "SwiftCompile",
+        not_expected_argv = [
+            "-avoid-emit-module-source-info",
+        ],
+        tags = all_tags,
+        target_under_test = "//test/fixtures/debug_settings:simple",
+    )
+
+    split_emit_swiftsourceinfo_test(
+        name = "{}_swiftmodule_only_emit_swiftsourceinfo".format(name),
+        mnemonic = "SwiftDeriveFiles",
+        not_expected_argv = [
+            "-avoid-emit-module-source-info",
+        ],
+        tags = all_tags,
+        target_under_test = "//test/fixtures/debug_settings:simple",
+    )
+
     split_swiftmodule_provider_test(
         name = "{}_split_provider".format(name),
         expected_files = [

tools/worker/output_file_map.cc

@@ -163,14 +163,6 @@ void OutputFileMap::UpdateForIncremental(
     auto copied_swiftdoc_path =
         MakeIncrementalOutputPath(swiftdoc_path, derived);
     incremental_inputs[swiftdoc_path] = copied_swiftdoc_path;
-
-    std::string swiftsourceinfo_path =
-        std::filesystem::path(swiftmodule_path)
-            .replace_extension(".swiftsourceinfo")
-            .string();
-    auto copied_swiftsourceinfo_path =
-        MakeIncrementalOutputPath(swiftsourceinfo_path, derived);
-    incremental_inputs[swiftsourceinfo_path] = copied_swiftsourceinfo_path;
   }
 
   if (!emit_objc_header_path.empty()) {

tools/worker/swift_runner.cc

@@ -472,17 +472,6 @@ SwiftRunner::SwiftRunner(const std::vector<std::string>& args,
 }
 
 int SwiftRunner::Run(std::ostream* stderr_stream, bool stdout_to_stderr) {
-  // In rules_swift < 3.x the .swiftsourceinfo files are unconditionally written
-  // to the module path. In rules_swift >= 3.x these same files are no longer
-  // tracked by Bazel unless explicitly requested. When using non-sandboxed
-  // mode, previous builds will contain these files and cause build failures
-  // when Swift tries to use them, in order to work around this compatibility
-  // issue, we check the module path for the presence of .swiftsourceinfo files
-  // and if they are present but not requested, we remove them.
-  if (swift_source_info_path_ != "" && !emit_swift_source_info_) {
-    std::filesystem::remove(swift_source_info_path_);
-  }
-
   int exit_code = 0;
 
   // Do the layering check before compilation. This gives a better error
@@ -759,8 +748,6 @@ std::vector<std::string> SwiftRunner::ParseArguments(Iterator itr) {
         target_label_ = std::string(value);
       } else if (absl::ConsumePrefix(&value, "-layering-check-deps-modules=")) {
         deps_modules_path_ = std::string(value);
-      } else if (value == "-emit-swiftsourceinfo") {
-        emit_swift_source_info_ = true;
       } else if (value == "-hermetic-pcm") {
         hermetic_pcm_ = true;
       } else if (absl::ConsumePrefix(
@@ -779,9 +766,6 @@ std::vector<std::string> SwiftRunner::ParseArguments(Iterator itr) {
     } else if (arg == "-emit-module-path") {
       ++it;
       emit_module_path_ = *it;
-      std::filesystem::path module_path(*it);
-      swift_source_info_path_ =
-          module_path.replace_extension(".swiftsourceinfo").string();
       out_args.push_back(*it);
     } else if (arg == "-module-name") {
       ++it;

tools/worker/swift_runner.h

@@ -223,12 +223,6 @@ class SwiftRunner {
   // index outputs into the `index_store_path` to integrate outputs with Bazel.
   std::string global_index_store_import_path_;
 
-  // The path where the module files will be written
-  std::string swift_source_info_path_;
-
-  // Whether `.swiftsourceinfo` files are being generated.
-  bool emit_swift_source_info_;
-
   // Whether `-Xwrapped-swift=-hermetic-pcm` was passed
   bool hermetic_pcm_;
 

tools/worker/work_processor.cc

@@ -89,7 +89,6 @@ void WorkProcessor::ProcessWorkRequest(
   std::string emit_objc_header_path;
   bool is_wmo = false;
   bool is_dump_ast = false;
-  bool emit_swift_source_info = false;
 
   std::string prev_arg;
   for (std::string arg : request.arguments) {
@@ -114,8 +113,6 @@ void WorkProcessor::ProcessWorkRequest(
       emit_objc_header_path = arg;
     } else if (ArgumentEnablesWMO(arg)) {
       is_wmo = true;
-    } else if (prev_arg == "-Xwrapped-swift=-emit-swiftsourceinfo") {
-      emit_swift_source_info = true;
     }
 
     if (!arg.empty()) {
@@ -167,18 +164,6 @@ void WorkProcessor::ProcessWorkRequest(
       const auto expected_object_path =
           std::filesystem::path(expected_object_pair.second);
 
-      // In rules_swift < 3.x the .swiftsourceinfo files are unconditionally
-      // written to the module path. In rules_swift >= 3.x these same files are
-      // no longer tracked by Bazel unless explicitly requested. When using
-      // non-sandboxed mode, previous builds will contain these files and cause
-      // build failures when Swift tries to use them, in order to work around
-      // this compatibility issue, we remove them if they are present but not
-      // requested.
-      if (!emit_swift_source_info &&
-          expected_object_path.extension() == ".swiftsourceinfo") {
-        std::filesystem::remove(LongPath(expected_object_path));
-      }
-
       // Bazel creates the intermediate directories for the files declared at
       // analysis time, but not any any deeper directories, like one can have
       // with -emit-objc-header-path, so we need to create those.