Add additional_objc_compiler_inputs to mixed_langauge_library (#1581)

This is needed over someone just adding these inputs to `hdrs`, because
of the modulemap generation.

---------

Signed-off-by: Brentley Jones <[email protected]>

Author: brentleyjones

doc/rules.md

@@ -1066,12 +1066,13 @@ swift_library(
 ## mixed_language_library
 
 <pre>
-mixed_language_library(*, <a href="#mixed_language_library-name">name</a>, <a href="#mixed_language_library-always_include_developer_search_paths">always_include_developer_search_paths</a>, <a href="#mixed_language_library-alwayslink">alwayslink</a>, <a href="#mixed_language_library-clang_copts">clang_copts</a>,
-                       <a href="#mixed_language_library-clang_defines">clang_defines</a>, <a href="#mixed_language_library-clang_deps">clang_deps</a>, <a href="#mixed_language_library-clang_srcs">clang_srcs</a>, <a href="#mixed_language_library-data">data</a>, <a href="#mixed_language_library-enable_modules">enable_modules</a>, <a href="#mixed_language_library-hdrs">hdrs</a>, <a href="#mixed_language_library-includes">includes</a>,
-                       <a href="#mixed_language_library-linkopts">linkopts</a>, <a href="#mixed_language_library-module_map">module_map</a>, <a href="#mixed_language_library-module_name">module_name</a>, <a href="#mixed_language_library-non_arc_srcs">non_arc_srcs</a>, <a href="#mixed_language_library-package_name">package_name</a>, <a href="#mixed_language_library-private_deps">private_deps</a>,
-                       <a href="#mixed_language_library-sdk_dylibs">sdk_dylibs</a>, <a href="#mixed_language_library-sdk_frameworks">sdk_frameworks</a>, <a href="#mixed_language_library-swift_copts">swift_copts</a>, <a href="#mixed_language_library-swift_defines">swift_defines</a>, <a href="#mixed_language_library-swift_plugins">swift_plugins</a>,
-                       <a href="#mixed_language_library-swift_srcs">swift_srcs</a>, <a href="#mixed_language_library-swiftc_inputs">swiftc_inputs</a>, <a href="#mixed_language_library-textual_hdrs">textual_hdrs</a>, <a href="#mixed_language_library-umbrella_header">umbrella_header</a>, <a href="#mixed_language_library-weak_sdk_frameworks">weak_sdk_frameworks</a>,
-                       <a href="#mixed_language_library-deps">deps</a>, <a href="#mixed_language_library-kwargs">**kwargs</a>)
+mixed_language_library(*, <a href="#mixed_language_library-name">name</a>, <a href="#mixed_language_library-additional_objc_compiler_inputs">additional_objc_compiler_inputs</a>,
+                       <a href="#mixed_language_library-always_include_developer_search_paths">always_include_developer_search_paths</a>, <a href="#mixed_language_library-alwayslink">alwayslink</a>, <a href="#mixed_language_library-clang_copts">clang_copts</a>, <a href="#mixed_language_library-clang_defines">clang_defines</a>,
+                       <a href="#mixed_language_library-clang_deps">clang_deps</a>, <a href="#mixed_language_library-clang_srcs">clang_srcs</a>, <a href="#mixed_language_library-data">data</a>, <a href="#mixed_language_library-enable_modules">enable_modules</a>, <a href="#mixed_language_library-hdrs">hdrs</a>, <a href="#mixed_language_library-includes">includes</a>, <a href="#mixed_language_library-linkopts">linkopts</a>,
+                       <a href="#mixed_language_library-module_map">module_map</a>, <a href="#mixed_language_library-module_name">module_name</a>, <a href="#mixed_language_library-non_arc_srcs">non_arc_srcs</a>, <a href="#mixed_language_library-package_name">package_name</a>, <a href="#mixed_language_library-private_deps">private_deps</a>, <a href="#mixed_language_library-sdk_dylibs">sdk_dylibs</a>,
+                       <a href="#mixed_language_library-sdk_frameworks">sdk_frameworks</a>, <a href="#mixed_language_library-swift_copts">swift_copts</a>, <a href="#mixed_language_library-swift_defines">swift_defines</a>, <a href="#mixed_language_library-swift_plugins">swift_plugins</a>, <a href="#mixed_language_library-swift_srcs">swift_srcs</a>,
+                       <a href="#mixed_language_library-swiftc_inputs">swiftc_inputs</a>, <a href="#mixed_language_library-textual_hdrs">textual_hdrs</a>, <a href="#mixed_language_library-umbrella_header">umbrella_header</a>, <a href="#mixed_language_library-weak_sdk_frameworks">weak_sdk_frameworks</a>, <a href="#mixed_language_library-deps">deps</a>,
+                       <a href="#mixed_language_library-kwargs">**kwargs</a>)
 </pre>
 
 Creates a mixed language library from a Clang and Swift library target     pair.
@@ -1086,6 +1087,7 @@ Once that is the case, this macro will be deprecated.
 | Name  | Description | Default Value |
 | :------------- | :------------- | :------------- |
 | <a id="mixed_language_library-name"></a>name |  The name of the target.   |  none |
+| <a id="mixed_language_library-additional_objc_compiler_inputs"></a>additional_objc_compiler_inputs |  Additional files that are referenced using `$(location ...)` in attributes that support location expansion.   |  `[]` |
 | <a id="mixed_language_library-always_include_developer_search_paths"></a>always_include_developer_search_paths |  If `True`, the developer framework search paths will be added to the swift compilation command. This enables a Swift module to access `XCTest` without having to mark the target as `testonly = True`.   |  `False` |
 | <a id="mixed_language_library-alwayslink"></a>alwayslink |  If true, any binary that depends (directly or indirectly) on this library will link in all the object files for the files listed in `clang_srcs` and `swift_srcs`, even if some contain no symbols referenced by the binary. This is useful if your code isn't explicitly called by code in the binary; for example, if you rely on runtime checks for protocol conformances added in extensions in the library but do not directly reference any other symbols in the object file that adds that conformance.   |  `False` |
 | <a id="mixed_language_library-clang_copts"></a>clang_copts |  The compiler flags for the clang library. These will only be used for the clang library. If you want them to affect the swift library as well, you need to pass them with `-Xcc` in `swift_copts`.   |  `[]` |

mixed_language/mixed_language_library.bzl

@@ -36,6 +36,7 @@ load("//swift:swift_library.bzl", "swift_library")
 def mixed_language_library(
         *,
         name,
+        additional_objc_compiler_inputs = [],
         always_include_developer_search_paths = False,
         alwayslink = False,
         clang_copts = [],
@@ -72,6 +73,9 @@ def mixed_language_library(
 
     Args:
         name: The name of the target.
+        additional_objc_compiler_inputs: Additional files that are referenced
+            using `$(location ...)` in attributes that support location
+            expansion.
         always_include_developer_search_paths: If `True`, the developer
             framework search paths will be added to the swift compilation
             command. This enables a Swift module to access `XCTest` without
@@ -360,7 +364,7 @@ a mixed language Swift library, use a clang only library rule like \
         name = clang_library_name,
         srcs = clang_srcs,
         alwayslink = alwayslink,
-        hdrs = adjusted_hdrs,
+        hdrs = adjusted_hdrs + additional_objc_compiler_inputs,
         non_arc_srcs = non_arc_srcs,
         # `internal_swift_interop_name` isn't needed here because
         # `_mixed_language_library` will explciitly set the module name. We set