Create 5.x base branch

MODULE.bazel

@@ -14,8 +14,10 @@ bazel_dep(name = "apple_support", version = "1.24.2", repo_name = "build_bazel_a
 bazel_dep(name = "rules_cc", version = "0.2.14")
 bazel_dep(name = "rules_shell", version = "0.3.0")
 bazel_dep(name = "platforms", version = "0.0.11")
-bazel_dep(name = "protobuf", version = "29.0", repo_name = "com_google_protobuf")
+bazel_dep(name = "protobuf", version = "30.0", repo_name = "com_google_protobuf")
 bazel_dep(name = "nlohmann_json", version = "3.12.0.bcr.1", repo_name = "com_github_nlohmann_json")
+bazel_dep(name = "abseil-cpp", version = "20250127.0")
+bazel_dep(name = "re2", version = "2025-11-05")
 bazel_dep(
     name = "swift_argument_parser",
     version = "1.3.1.2",

doc/providers.md

@@ -110,11 +110,12 @@ Propagates Swift-specific information about a `proto_library`.
 
 <pre>
 SwiftToolchainInfo(<a href="#SwiftToolchainInfo-action_configs">action_configs</a>, <a href="#SwiftToolchainInfo-cc_language">cc_language</a>, <a href="#SwiftToolchainInfo-cc_toolchain_info">cc_toolchain_info</a>, <a href="#SwiftToolchainInfo-clang_implicit_deps_providers">clang_implicit_deps_providers</a>,
-                   <a href="#SwiftToolchainInfo-const_protocols_to_gather">const_protocols_to_gather</a>, <a href="#SwiftToolchainInfo-cross_import_overlays">cross_import_overlays</a>, <a href="#SwiftToolchainInfo-debug_outputs_provider">debug_outputs_provider</a>,
-                   <a href="#SwiftToolchainInfo-developer_dirs">developer_dirs</a>, <a href="#SwiftToolchainInfo-entry_point_linkopts_provider">entry_point_linkopts_provider</a>, <a href="#SwiftToolchainInfo-feature_allowlists">feature_allowlists</a>,
-                   <a href="#SwiftToolchainInfo-generated_header_module_implicit_deps_providers">generated_header_module_implicit_deps_providers</a>, <a href="#SwiftToolchainInfo-implicit_deps_providers">implicit_deps_providers</a>,
-                   <a href="#SwiftToolchainInfo-module_aliases">module_aliases</a>, <a href="#SwiftToolchainInfo-package_configurations">package_configurations</a>, <a href="#SwiftToolchainInfo-requested_features">requested_features</a>, <a href="#SwiftToolchainInfo-root_dir">root_dir</a>, <a href="#SwiftToolchainInfo-swift_worker">swift_worker</a>,
-                   <a href="#SwiftToolchainInfo-test_configuration">test_configuration</a>, <a href="#SwiftToolchainInfo-tool_configs">tool_configs</a>, <a href="#SwiftToolchainInfo-unsupported_features">unsupported_features</a>)
+                   <a href="#SwiftToolchainInfo-codegen_batch_size">codegen_batch_size</a>, <a href="#SwiftToolchainInfo-const_protocols_to_gather">const_protocols_to_gather</a>, <a href="#SwiftToolchainInfo-cross_import_overlays">cross_import_overlays</a>,
+                   <a href="#SwiftToolchainInfo-debug_outputs_provider">debug_outputs_provider</a>, <a href="#SwiftToolchainInfo-developer_dirs">developer_dirs</a>, <a href="#SwiftToolchainInfo-entry_point_linkopts_provider">entry_point_linkopts_provider</a>,
+                   <a href="#SwiftToolchainInfo-feature_allowlists">feature_allowlists</a>, <a href="#SwiftToolchainInfo-generated_header_module_implicit_deps_providers">generated_header_module_implicit_deps_providers</a>,
+                   <a href="#SwiftToolchainInfo-implicit_deps_providers">implicit_deps_providers</a>, <a href="#SwiftToolchainInfo-module_aliases">module_aliases</a>, <a href="#SwiftToolchainInfo-package_configurations">package_configurations</a>,
+                   <a href="#SwiftToolchainInfo-requested_features">requested_features</a>, <a href="#SwiftToolchainInfo-root_dir">root_dir</a>, <a href="#SwiftToolchainInfo-swift_worker">swift_worker</a>, <a href="#SwiftToolchainInfo-test_configuration">test_configuration</a>, <a href="#SwiftToolchainInfo-tool_configs">tool_configs</a>,
+                   <a href="#SwiftToolchainInfo-unsupported_features">unsupported_features</a>)
 </pre>
 
 Propagates information about a Swift toolchain to compilation and linking rules
@@ -128,6 +129,7 @@ that use the toolchain.
 | <a id="SwiftToolchainInfo-cc_language"></a>cc_language |  The `language` that should be passed to `cc_common` APIs that take it as an argument.    |
 | <a id="SwiftToolchainInfo-cc_toolchain_info"></a>cc_toolchain_info |  The `cc_common.CcToolchainInfo` provider from the Bazel C++ toolchain that this Swift toolchain depends on.    |
 | <a id="SwiftToolchainInfo-clang_implicit_deps_providers"></a>clang_implicit_deps_providers |  A `struct` with the following fields, which represent providers from targets that should be added as implicit dependencies of any precompiled explicit C/Objective-C modules:<br><br>*   `cc_infos`: A list of `CcInfo` providers from targets specified as the     toolchain's implicit dependencies.<br><br>*   `swift_infos`: A list of `SwiftInfo` providers from targets specified as the     toolchain's implicit dependencies.<br><br>For ease of use, this field is never `None`; it will always be a valid `struct` containing the fields described above, even if those lists are empty.    |
+| <a id="SwiftToolchainInfo-codegen_batch_size"></a>codegen_batch_size |  The number of files to pass to the compiler in a single code generation action (one that compiles object files from Swift source files).    |
 | <a id="SwiftToolchainInfo-const_protocols_to_gather"></a>const_protocols_to_gather |  `File`. A JSON file specifying a list of protocols for extraction of conformances' const values.    |
 | <a id="SwiftToolchainInfo-cross_import_overlays"></a>cross_import_overlays |  A list of `SwiftCrossImportOverlayInfo` providers whose `SwiftInfo` providers will be automatically injected into the dependencies of Swift compilations if their declaring module and bystanding module are both already declared as dependencies.    |
 | <a id="SwiftToolchainInfo-debug_outputs_provider"></a>debug_outputs_provider |  An optional function that provides toolchain-specific logic around the handling of additional debug outputs for `swift_binary` and `swift_test` targets.<br><br>If specified, this function must take the following keyword arguments:<br><br>*   `ctx`: The rule context of the calling binary or test rule.<br><br>It must return a `struct` with the following fields:<br><br>*   `additional_outputs`: Additional outputs expected from the linking action.<br><br>*   `variables_extension`: A dictionary of additional crosstool variables to     pass to the linking action.    |
@@ -140,7 +142,7 @@ that use the toolchain.
 | <a id="SwiftToolchainInfo-package_configurations"></a>package_configurations |  A list of `SwiftPackageConfigurationInfo` providers that specify additional compilation configuration options that are applied to targets on a per-package basis.    |
 | <a id="SwiftToolchainInfo-requested_features"></a>requested_features |  `List` of `string`s. Features that should be implicitly enabled by default for targets built using this toolchain, unless overridden by the user by listing their negation in the `features` attribute of a target/package or in the `--features` command line flag.<br><br>These features determine various compilation and debugging behaviors of the Swift build rules, and they are also passed to the C++ APIs used when linking (so features defined in CROSSTOOL may be used here).    |
 | <a id="SwiftToolchainInfo-root_dir"></a>root_dir |  `String`. The workspace-relative root directory of the toolchain.    |
-| <a id="SwiftToolchainInfo-swift_worker"></a>swift_worker |  `File`. The executable representing the worker executable used to invoke the compiler and other Swift tools (for both incremental and non-incremental compiles).    |
+| <a id="SwiftToolchainInfo-swift_worker"></a>swift_worker |  `File`. The executable that wraps Swift compiler invocations.    |
 | <a id="SwiftToolchainInfo-test_configuration"></a>test_configuration |  `Struct` containing the following fields:<br><br>*   `binary_name`: A template string used to compute the name of the output     binary for `swift_test` rules. Any occurrences of the string `"{name}"` will     be substituted by the name of the target.<br><br>*   `env`: A `dict` of environment variables to be set when running tests     that were built with this toolchain.<br><br>*   `execution_requirements`: A `dict` of execution requirements for tests     that were built with this toolchain.<br><br>*   `objc_test_discovery`: A Boolean value indicating whether test targets     should discover tests dynamically using the Objective-C runtime.<br><br>*   `test_linking_contexts`: A list of `CcLinkingContext`s that provide     additional flags to use when linking test binaries.<br><br>This is used, for example, with Xcode-based toolchains to ensure that the `xctest` helper and coverage tools are found in the correct developer directory when running tests.    |
 | <a id="SwiftToolchainInfo-tool_configs"></a>tool_configs |  This field is an internal implementation detail of the build rules.    |
 | <a id="SwiftToolchainInfo-unsupported_features"></a>unsupported_features |  `List` of `string`s. Features that should be implicitly disabled by default for targets built using this toolchain, unless overridden by the user by listing them in the `features` attribute of a target/package or in the `--features` command line flag.<br><br>These features determine various compilation and debugging behaviors of the Swift build rules, and they are also passed to the C++ APIs used when linking (so features defined in CROSSTOOL may be used here).    |

swift/internal/BUILD

@@ -99,9 +99,9 @@ bzl_library(
         ":feature_names",
         ":features",
         ":module_maps",
+        ":optimization",
         ":utils",
         ":vfsoverlay",
-        ":wmo",
         "//swift:providers",
         "@bazel_skylib//lib:paths",
         "@bazel_skylib//lib:sets",
@@ -314,8 +314,8 @@ bzl_library(
 )
 
 bzl_library(
-    name = "wmo",
-    srcs = ["wmo.bzl"],
+    name = "optimization",
+    srcs = ["optimization.bzl"],
     visibility = ["//swift:__subpackages__"],
     deps = [
         ":feature_names",

swift/internal/action_names.bzl

@@ -20,16 +20,20 @@
 SWIFT_ACTION_AUTOLINK_EXTRACT = "SwiftAutolinkExtract"
 
 # Compiles one or more `.swift` source files into a `.swiftmodule` and
-# object files.
+# object files. This is the legacy mode that emits all outputs from a single
+# driver invocation.
 SWIFT_ACTION_COMPILE = "SwiftCompile"
 
+# Emits the object files and other per-source-file outputs for a a batch of
+# `.swift` source files in a module.
+SWIFT_ACTION_COMPILE_CODEGEN = "SwiftCompileCodegen"
+
+# Compiles one or more `.swift` source files into a `.swiftmodule`.
+SWIFT_ACTION_COMPILE_MODULE = "SwiftCompileModule"
+
 # Compiles a `.swiftinterface` file into a `.swiftmodule` file.
 SWIFT_ACTION_COMPILE_MODULE_INTERFACE = "SwiftCompileModuleInterface"
 
-# Produces files that are usually fallout of the compilation such as
-# .swiftmodule, -Swift.h and more.
-SWIFT_ACTION_DERIVE_FILES = "SwiftDeriveFiles"
-
 # Produces an AST file for each swift source file in a module.
 SWIFT_ACTION_DUMP_AST = "SwiftDumpAST"
 
@@ -54,8 +58,9 @@ def all_action_names():
     return (
         SWIFT_ACTION_AUTOLINK_EXTRACT,
         SWIFT_ACTION_COMPILE,
+        SWIFT_ACTION_COMPILE_CODEGEN,
+        SWIFT_ACTION_COMPILE_MODULE,
         SWIFT_ACTION_COMPILE_MODULE_INTERFACE,
-        SWIFT_ACTION_DERIVE_FILES,
         SWIFT_ACTION_DUMP_AST,
         SWIFT_ACTION_MODULEWRAP,
         SWIFT_ACTION_PRECOMPILE_C_MODULE,
@@ -67,5 +72,6 @@ def all_compile_action_names():
     """Returns all actions that compile source files."""
     return [
         SWIFT_ACTION_COMPILE,
-        SWIFT_ACTION_DERIVE_FILES,
+        SWIFT_ACTION_COMPILE_CODEGEN,
+        SWIFT_ACTION_COMPILE_MODULE,
     ]

swift/internal/actions.bzl

@@ -191,17 +191,7 @@ def run_toolchain_action(
     # tool as the executable directly.
     tools = []
     tool_executable_args = actions.args()
-    if tool_config.worker_mode:
-        # Only enable persistent workers if the toolchain supports response
-        # files, because the worker unconditionally writes its arguments into
-        # one to prevent command line overflow in this mode.
-        if (
-            tool_config.worker_mode == "persistent" and
-            tool_config.use_param_file
-        ):
-            execution_requirements["supports-workers"] = "1"
-            execution_requirements["requires-worker-protocol"] = "json"
-
+    if tool_config.wrapped_by_worker:
         executable = swift_toolchain.swift_worker
         tool_executable_args.add(tool_config.executable)
         if not types.is_string(tool_config.executable):