Add example with deps in swift_import

swift/toolchains/config/compile_config.bzl

@@ -1861,7 +1861,7 @@ def _disable_autolink_framework_copts(library_path):
     )
 
 def _swift_module_search_path_map_fn(module):
-    """Returns the path to the directory containing a `.swiftmodule` file.
+    """Returns the path to the directory containing a Swift module file.
 
     This function is intended to be used as a mapping function for modules
     passed into `Args.add_all`.
@@ -1872,10 +1872,16 @@ def _swift_module_search_path_map_fn(module):
             modules of a `SwiftInfo` provider.
 
     Returns:
-        The dirname of the module's `.swiftmodule` file.
+        The dirname of the module's `.swiftmodule` or `.swiftinterface` file.
     """
     if module.swift:
-        search_path = module.swift.swiftmodule.dirname
+        # For modules with .swiftinterface files (like swift_import), we need
+        # to use the directory containing the .swiftinterface so that Swift
+        # can find it when compiling dependent module interfaces.
+        if module.swift.swiftinterface:
+            search_path = module.swift.swiftinterface.dirname
+        else:
+            search_path = module.swift.swiftmodule.dirname
 
         # If the dirname also ends in .swiftmodule, remove it as well so that
         # the compiler finds the module *directory*.

test/fixtures/module_interface/BUILD

@@ -13,7 +13,10 @@ swift_binary(
     name = "client",
     srcs = ["Client.swift"],
     tags = FIXTURE_TAGS,
-    deps = [":toy_module"],
+    deps = [
+        ":toy_module",
+        ":toy_module_consumer",
+    ],
 )
 
 swift_import(
@@ -26,3 +29,15 @@ swift_import(
     swiftinterface = "//test/fixtures/module_interface/library:toy_outputs/ToyModule.swiftinterface",
     tags = FIXTURE_TAGS,
 )
+
+swift_import(
+    name = "toy_module_consumer",
+    archives = [
+        "//test/fixtures/module_interface/library_consumer:toy_consumer_outputs/libToyModuleConsumer.a",
+    ],
+    module_name = "ToyModuleConsumer",
+    swiftdoc = "//test/fixtures/module_interface/library_consumer:toy_consumer_outputs/ToyModuleConsumer.swiftdoc",
+    swiftinterface = "//test/fixtures/module_interface/library_consumer:toy_consumer_outputs/ToyModuleConsumer.swiftinterface",
+    tags = FIXTURE_TAGS,
+    deps = [":toy_module"],
+)

test/fixtures/module_interface/Client.swift

@@ -13,12 +13,14 @@
 // limitations under the License.
 
 import ToyModule
+import ToyModuleConsumer
 
 @main
 struct Main {
   static func main() {
     let value = ToyValue(number: 10)
     print(value.stringValue)
     print(value.squared())
+    printToyValue()
   }
 }

test/fixtures/module_interface/library_consumer/BUILD

@@ -0,0 +1,52 @@
+load("//swift:swift_library.bzl", "swift_library")
+load(
+    "//test/fixtures:common.bzl",
+    "FIXTURE_TAGS",
+)
+load(
+    "//test/rules:swift_library_artifact_collector.bzl",
+    "swift_library_artifact_collector",
+)
+
+package(
+    default_testonly = True,
+    default_visibility = ["//test:__subpackages__"],
+)
+
+licenses(["notice"])
+
+# Checking in pre-built artifacts like a `.swiftinterface` and static libraries
+# would require different artifacts for every platform the test might run on.
+# Instead, build it on-demand but forward the outputs using the "artifact
+# collector" rule below to make them act as if they were pre-built outputs when
+# referenced by the `swift_import` rule.
+#
+# These must be in a separate package than the `swift_import` target because
+# that rule propagates its pre-built inputs in `DefaultInfo`.
+
+swift_library(
+    name = "toy_module_consumer",
+    srcs = ["ToyConsumer.swift"],
+    library_evolution = True,
+    module_name = "ToyModuleConsumer",
+    tags = FIXTURE_TAGS,
+    deps = ["//test/fixtures/module_interface/library:toy_module_library"],
+)
+
+swift_library_artifact_collector(
+    name = "toy_module_consumer_artifact_collector",
+    static_library = "toy_consumer_outputs/libToyModuleConsumer.a",
+    swiftdoc = "toy_consumer_outputs/ToyModuleConsumer.swiftdoc",
+    swiftinterface = "toy_consumer_outputs/ToyModuleConsumer.swiftinterface",
+    tags = FIXTURE_TAGS,
+    target = ":toy_module_consumer",
+    target_compatible_with = ["@platforms//os:macos"],
+)
+
+swift_library(
+    name = "toy_module_consumer_without_library_evolution",
+    srcs = ["ToyConsumer.swift"],
+    library_evolution = False,
+    module_name = "ToyModuleConsumerNoEvolution",
+    tags = FIXTURE_TAGS,
+)

test/fixtures/module_interface/library_consumer/ToyConsumer.swift

@@ -0,0 +1,19 @@
+// Copyright 2024 The Bazel Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import ToyModule
+
+public func printToyValue() {
+  print(ToyValue(number: 42))
+}