fix: remove duplicate srcs when evaluating clang files

examples/example_infos.bzl

@@ -149,6 +149,7 @@ _macos_single_bazel_version_test_examples = [
     "xcmetrics_example",
     "tca_example",
     "symlink_example",
+    "yoga_example",
 ]
 
 _linux_single_bazel_version_test_examples = []

examples/yoga_example/BUILD.bazel

@@ -0,0 +1,33 @@
+load("@bazel_gazelle//:def.bzl", "gazelle", "gazelle_binary")
+load("@cgrindel_bazel_starlib//bzltidy:defs.bzl", "tidy")
+
+tidy(
+    name = "tidy",
+    targets = [
+        ":update_build_files",
+    ],
+)
+
+# MARK: - Gazelle
+
+# Ignore the Swift build folder
+# gazelle:exclude .build
+
+gazelle_binary(
+    name = "gazelle_bin",
+    languages = [
+        "@bazel_skylib_gazelle_plugin//bzl",
+        "@rules_swift_package_manager//gazelle",
+    ],
+)
+
+gazelle(
+    name = "update_build_files",
+    data = [
+        "@swift_deps_info//:swift_deps_index",
+    ],
+    extra_args = [
+        "-swift_dependency_index=$(location @swift_deps_info//:swift_deps_index)",
+    ],
+    gazelle = ":gazelle_bin",
+)

examples/yoga_example/MODULE.bazel

@@ -0,0 +1,59 @@
+bazel_dep(
+    name = "rules_swift_package_manager",
+    version = "0.0.0",
+)
+local_path_override(
+    module_name = "rules_swift_package_manager",
+    path = "../..",
+)
+
+bazel_dep(name = "cgrindel_bazel_starlib", version = "0.23.0")
+bazel_dep(name = "bazel_skylib", version = "1.7.1")
+
+# The apple_support bazel_dep must come before the rules_cc.
+# https://github.com/bazelbuild/apple_support#incompatible-toolchain-resolution
+bazel_dep(name = "apple_support", version = "1.17.1")
+bazel_dep(
+    name = "rules_swift",
+    version = "2.3.1",
+    repo_name = "build_bazel_rules_swift",
+)
+bazel_dep(
+    name = "rules_apple",
+    version = "3.16.1",
+    repo_name = "build_bazel_rules_apple",
+)
+
+bazel_dep(
+    name = "bazel_skylib_gazelle_plugin",
+    version = "1.7.1",
+    dev_dependency = True,
+)
+bazel_dep(
+    name = "gazelle",
+    version = "0.41.0",
+    dev_dependency = True,
+    repo_name = "bazel_gazelle",
+)
+
+apple_cc_configure = use_extension(
+    "@apple_support//crosstool:setup.bzl",
+    "apple_cc_configure_extension",
+)
+use_repo(apple_cc_configure, "local_config_apple_cc")
+
+swift_deps = use_extension(
+    "@rules_swift_package_manager//:extensions.bzl",
+    "swift_deps",
+)
+swift_deps.from_package(
+    declare_swift_deps_info = True,
+    resolved = "//:Package.resolved",
+    swift = "//:Package.swift",
+)
+use_repo(
+    swift_deps,
+    "swift_deps_info",
+    "swift_package",
+    "swiftpkg_yoga",
+)

examples/yoga_example/Package.swift

@@ -0,0 +1,10 @@
+// swift-tools-version: 6.0
+
+import PackageDescription
+
+let package = Package(
+    name: "YogaKitExample",
+    dependencies: [
+        .package(url: "https://github.com/facebook/yoga.git", from: "3.1.0"),
+    ]
+)

examples/yoga_example/README.md

@@ -0,0 +1,4 @@
+# Yoga Example
+
+This example demonstrates support for clang, with a root public headers search paths. For example, the file
+`external/swiftpkg_yoga/yoga/module.modulemap` will be duplicated when we have both `sources: ["yoga"],` and `publicHeadersPath: ".",` in `Package.swift`. Removing duplicate from the srcs read is useful in this case.

examples/yoga_example/Tests/YogaTests/BUILD.bazel

@@ -0,0 +1,12 @@
+load("@build_bazel_rules_swift//swift:swift.bzl", "swift_test")
+
+swift_test(
+    name = "YogaTests",
+    srcs = [
+        "YogaTests.swift",
+    ],
+    module_name = "YogaTests",
+    deps = [
+        "@swiftpkg_yoga//:yoga",
+    ],
+)

examples/yoga_example/Tests/YogaTests/YogaTests.swift

@@ -0,0 +1,9 @@
+@testable import Yoga
+import XCTest
+
+class YogaTests: XCTestCase {
+    func testSomething() {
+        let view = UIView()
+        view.flex.isEnabled = true
+    }
+}

examples/yoga_example/WORKSPACE

@@ -0,0 +1 @@
+# Intentionally blank: Using bzlmod

examples/yoga_example/WORKSPACE.bzlmod

@@ -0,0 +1,2 @@
+# Intentionally blank
+# This exists to force Bazel in bzlmod mode to be strict.

examples/yoga_example/do_test

@@ -0,0 +1,15 @@
+#!/usr/bin/env bash
+
+set -o errexit -o nounset -o pipefail
+
+script_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" > /dev/null && pwd)"
+
+# Use the Bazel binary specified by the integration test. Otherise, fall back 
+# to bazel.
+bazel="${BIT_BAZEL_BINARY:-bazel}"
+
+# Generate Swift external deps and update build files
+"${bazel}" run //:tidy
+
+# Ensure that it builds and tests pass
+"${bazel}" test //...

swiftpkg/internal/clang_files.bzl

@@ -250,7 +250,7 @@ def _collect_files(
 
     modulemap = None
     modulemap_orig_path = None
-    for orig_path in all_srcs:
+    for orig_path in depset(all_srcs).to_list():
         path = _relativize(orig_path, relative_to)
         _root, ext = paths.split_extension(path)
         if lists.contains(_HEADER_EXTS, ext):