Refine the change to ignore .docc files rather than emit warnings to avoid having multiple definitions for the same file extension (#3620)

Ignore .docc files rather than emitting warnings, since it's useful to have them in packages without warnings.

Unlike other Xcode-specific file types, such as Storyboards and Asset Catalogs, the .docc bundles are not needed for correctness during the build, and should therefore not trigger warnings.

This is a refinement of the fix in #3609.

rdar://78133445

Author: abertelrud

Sources/Commands/SwiftTool.swift

@@ -561,7 +561,7 @@ public class SwiftTool {
             config: try getSwiftPMConfig(),
             repositoryProvider: provider,
             netrcFilePath: try resolvedNetrcFilePath(),
-            additionalFileRules: isXcodeBuildSystemEnabled ? FileRuleDescription.xcbuildFileTypes : [],
+            additionalFileRules: isXcodeBuildSystemEnabled ? FileRuleDescription.xcbuildFileTypes : FileRuleDescription.swiftpmFileTypes,
             isResolverPrefetchingEnabled: options.shouldEnableResolverPrefetching,
             skipUpdate: options.skipDependencyUpdate,
             enableResolverTrace: options.enableResolverTrace,

Sources/PackageLoading/TargetSourcesBuilder.swift

@@ -66,15 +66,9 @@ public struct TargetSourcesBuilder {
         self.defaultLocalization = defaultLocalization
         self.diags = diags
         self.targetPath = path
-        
-        // Configure the file rules that determine how files of various types are processed.  We always start with the builtins.
-        var fileRules = FileRuleDescription.builtinRules
-        // In version 5.4 and earlier, we did not support `additionalFileRules` and always implicitly included the XCBuild file types.
-        fileRules += (toolsVersion <= ToolsVersion.v5_4) ? FileRuleDescription.xcbuildFileTypes : additionalFileRules
-        // At the end we add the ignored types.  They might duplicate some of the rules in `additionalFileRules`, but in that case, the rule to ignore the file type will never be reached.
-        fileRules += FileRuleDescription.ignoredFileTypes
-        self.rules = fileRules
-        
+        // In version 5.4 and earlier, SwiftPM did not support `additionalFileRules` and always implicitly included XCBuild file types.
+        let actualAdditionalRules = (toolsVersion <= ToolsVersion.v5_4 ? FileRuleDescription.xcbuildFileTypes : additionalFileRules)
+        self.rules = FileRuleDescription.builtinRules + actualAdditionalRules
         self.toolsVersion = toolsVersion
         self.fs = fs
         let excludedPaths = target.exclude.map{ path.appending(RelativePath($0)) }
@@ -611,7 +605,7 @@ public struct FileRuleDescription {
         )
     }()
 
-    /// File types related to DocC.
+    /// File rule to ignore .docc (in the SwiftPM build system).
     public static let docc: FileRuleDescription = {
         .init(
             rule: .ignored,
@@ -637,9 +631,8 @@ public struct FileRuleDescription {
         metal,
     ]
 
-    /// List of file types that are ignored in this version of SwiftPM CLI
-    /// (that don't generate warnings for being unhandled).
-    public static let ignoredFileTypes: [FileRuleDescription] = [
+    /// List of file types that apply just to the SwiftPM build system.
+    public static let swiftpmFileTypes: [FileRuleDescription] = [
         docc,
     ]
 }

Sources/SPMTestSupport/misc.swift

@@ -239,7 +239,7 @@ public func loadPackageGraph(
     return try PackageGraph.load(
         root: graphRoot,
         identityResolver: identityResolver,
-        additionalFileRules: useXCBuildFileRules ? FileRuleDescription.xcbuildFileTypes : [],
+        additionalFileRules: useXCBuildFileRules ? FileRuleDescription.xcbuildFileTypes : FileRuleDescription.swiftpmFileTypes,
         externalManifests: externalManifests,
         binaryArtifacts: binaryArtifacts,
         diagnostics: diagnostics,

Tests/PackageLoadingTests/TargetSourcesBuilderTests.swift

@@ -662,7 +662,7 @@ class TargetSourcesBuilderTests: XCTestCase {
         XCTAssertEqual(diags.diagnostics.map { $0.description }, ["found 1 file(s) which are unhandled; explicitly declare them as resources or exclude from the target\n    /Foo.xcdatamodel\n"])
     }
 
-    func testIgnoredFileTypesDoNoCauseWarnings() throws {
+    func testDocCFilesDoNotCauseWarningOutsideXCBuild() throws {
         let target = try TargetDescription(
             name: "Foo",
             path: nil,
@@ -687,6 +687,7 @@ class TargetSourcesBuilderTests: XCTestCase {
             target: target,
             path: .root,
             defaultLocalization: nil,
+            additionalFileRules: FileRuleDescription.swiftpmFileTypes,
             toolsVersion: .v5_5,
             fs: fs,
             diags: diags