Replace plugin root regex with SafeDIRootScanner

Package.swift

@@ -122,7 +122,33 @@ let package = Package(
 		.plugin(
 			name: "SafeDIGenerator",
 			capability: .buildTool(),
-			dependencies: ["SafeDITool"],
+			dependencies: [
+				"SafeDITool",
+			],
+		),
+		// A lightweight executable that performs lexical root discovery without SwiftSyntax.
+		// SPM plugins run this in-process via symlinked sources.
+		// This target exists as a standalone executable for non-SPM build systems (e.g. Buck, Bazel)
+		// that need to invoke root scanning as a separate process.
+		.executableTarget(
+			name: "SafeDIRootScanner",
+			dependencies: [
+				.product(name: "ArgumentParser", package: "swift-argument-parser"),
+			],
+			swiftSettings: [
+				.swiftLanguageMode(.v6),
+			],
+		),
+		.testTarget(
+			name: "SafeDIRootScannerTests",
+			dependencies: [
+				.product(name: "ArgumentParser", package: "swift-argument-parser"),
+				"SafeDICore",
+				"SafeDIRootScanner",
+			],
+			swiftSettings: [
+				.swiftLanguageMode(.v6),
+			],
 		),
 		.executableTarget(
 			name: "SafeDITool",
@@ -139,6 +165,7 @@ let package = Package(
 			name: "SafeDIToolTests",
 			dependencies: [
 				.product(name: "ArgumentParser", package: "swift-argument-parser"),
+				"SafeDIRootScanner",
 				"SafeDITool",
 			],
 			swiftSettings: [

Plugins/SafeDIGenerator/RelativePath.swift

@@ -0,0 +1 @@
+../../Sources/SafeDIRootScanner/RelativePath.swift

Plugins/SafeDIGenerator/RootScanner.swift

@@ -0,0 +1 @@
+../../Sources/SafeDIRootScanner/RootScanner.swift

Plugins/SafeDIGenerator/SafeDIGenerateDependencyTree.swift

@@ -48,33 +48,24 @@ struct SafeDIGenerateDependencyTree: BuildToolPlugin {
 			}
 
 		let allSwiftFiles = targetSwiftFiles + dependenciesSourceFiles
-		let rootFiles = findFilesWithRoots(in: allSwiftFiles)
-		guard !rootFiles.isEmpty else {
-			return []
-		}
-
-		let outputFiles = zip(rootFiles, outputFileNames(for: rootFiles)).map { _, name in
-			outputDirectory.appending(path: name)
-		}
-
 		let packageRoot = context.package.directoryURL
 		let inputSourcesFile = context.pluginWorkDirectoryURL.appending(path: "InputSwiftFiles.csv")
-		try allSwiftFiles
-			.map { relativePath(for: $0, relativeTo: packageRoot) }
-			.joined(separator: ",")
-			.write(
-				to: inputSourcesFile,
-				atomically: true,
-				encoding: .utf8,
-			)
+		try writeInputSwiftFilesCSV(
+			allSwiftFiles,
+			relativeTo: packageRoot,
+			to: inputSourcesFile,
+		)
 
 		let manifestFile = context.pluginWorkDirectoryURL.appending(path: "SafeDIManifest.json")
-		try writeManifest(
-			dependencyTreeInputFiles: rootFiles,
+		let outputFiles = try runRootScanner(
+			inputSourcesFile: inputSourcesFile,
+			projectRoot: packageRoot,
 			outputDirectory: outputDirectory,
-			to: manifestFile,
-			relativeTo: packageRoot,
+			manifestFile: manifestFile,
 		)
+		guard !outputFiles.isEmpty else {
+			return []
+		}
 
 		let arguments = [
 			inputSourcesFile.path(percentEncoded: false),
@@ -163,34 +154,25 @@ extension Target {
 				return []
 			}
 
-			let rootFiles = findFilesWithRoots(in: inputSwiftFiles)
-			guard !rootFiles.isEmpty else {
-				return []
-			}
-
 			let outputDirectory = context.pluginWorkDirectoryURL.appending(path: "SafeDIOutput")
-			let outputFiles = zip(rootFiles, outputFileNames(for: rootFiles)).map { _, name in
-				outputDirectory.appending(path: name)
-			}
-
 			let projectRoot = context.xcodeProject.directoryURL
 			let inputSourcesFile = context.pluginWorkDirectoryURL.appending(path: "InputSwiftFiles.csv")
-			try inputSwiftFiles
-				.map { relativePath(for: $0, relativeTo: projectRoot) }
-				.joined(separator: ",")
-				.write(
-					to: inputSourcesFile,
-					atomically: true,
-					encoding: .utf8,
-				)
+			try writeInputSwiftFilesCSV(
+				inputSwiftFiles,
+				relativeTo: projectRoot,
+				to: inputSourcesFile,
+			)
 
 			let manifestFile = context.pluginWorkDirectoryURL.appending(path: "SafeDIManifest.json")
-			try writeManifest(
-				dependencyTreeInputFiles: rootFiles,
+			let outputFiles = try runRootScanner(
+				inputSourcesFile: inputSourcesFile,
+				projectRoot: projectRoot,
 				outputDirectory: outputDirectory,
-				to: manifestFile,
-				relativeTo: projectRoot,
+				manifestFile: manifestFile,
 			)
+			guard !outputFiles.isEmpty else {
+				return []
+			}
 
 			let arguments = [
 				inputSourcesFile.path(percentEncoded: false),

Plugins/SafeDIGenerator/SharedRootScanner.swift

@@ -0,0 +1 @@
+../SharedRootScanner.swift

Plugins/SafeDIPrebuiltGenerator/RelativePath.swift

@@ -0,0 +1 @@
+../../Sources/SafeDIRootScanner/RelativePath.swift

Plugins/SafeDIPrebuiltGenerator/RootScanner.swift

@@ -0,0 +1 @@
+../../Sources/SafeDIRootScanner/RootScanner.swift

Plugins/SafeDIPrebuiltGenerator/SafeDIGenerateDependencyTree.swift

@@ -48,33 +48,24 @@ struct SafeDIGenerateDependencyTree: BuildToolPlugin {
 			}
 
 		let allSwiftFiles = targetSwiftFiles + dependenciesSourceFiles
-		let rootFiles = findFilesWithRoots(in: allSwiftFiles)
-		guard !rootFiles.isEmpty else {
-			return []
-		}
-
-		let outputFiles = zip(rootFiles, outputFileNames(for: rootFiles)).map { _, name in
-			outputDirectory.appending(path: name)
-		}
-
 		let packageRoot = context.package.directoryURL
 		let inputSourcesFile = context.pluginWorkDirectoryURL.appending(path: "InputSwiftFiles.csv")
-		try allSwiftFiles
-			.map { relativePath(for: $0, relativeTo: packageRoot) }
-			.joined(separator: ",")
-			.write(
-				to: inputSourcesFile,
-				atomically: true,
-				encoding: .utf8,
-			)
+		try writeInputSwiftFilesCSV(
+			allSwiftFiles,
+			relativeTo: packageRoot,
+			to: inputSourcesFile,
+		)
 
 		let manifestFile = context.pluginWorkDirectoryURL.appending(path: "SafeDIManifest.json")
-		try writeManifest(
-			dependencyTreeInputFiles: rootFiles,
+		let outputFiles = try runRootScanner(
+			inputSourcesFile: inputSourcesFile,
+			projectRoot: packageRoot,
 			outputDirectory: outputDirectory,
-			to: manifestFile,
-			relativeTo: packageRoot,
+			manifestFile: manifestFile,
 		)
+		guard !outputFiles.isEmpty else {
+			return []
+		}
 
 		let arguments = [
 			inputSourcesFile.path(percentEncoded: false),
@@ -173,34 +164,25 @@ extension Target {
 				return []
 			}
 
-			let rootFiles = findFilesWithRoots(in: inputSwiftFiles)
-			guard !rootFiles.isEmpty else {
-				return []
-			}
-
 			let outputDirectory = context.pluginWorkDirectoryURL.appending(path: "SafeDIOutput")
-			let outputFiles = zip(rootFiles, outputFileNames(for: rootFiles)).map { _, name in
-				outputDirectory.appending(path: name)
-			}
-
 			let projectRoot = context.xcodeProject.directoryURL
 			let inputSourcesFile = context.pluginWorkDirectoryURL.appending(path: "InputSwiftFiles.csv")
-			try inputSwiftFiles
-				.map { relativePath(for: $0, relativeTo: projectRoot) }
-				.joined(separator: ",")
-				.write(
-					to: inputSourcesFile,
-					atomically: true,
-					encoding: .utf8,
-				)
+			try writeInputSwiftFilesCSV(
+				inputSwiftFiles,
+				relativeTo: projectRoot,
+				to: inputSourcesFile,
+			)
 
 			let manifestFile = context.pluginWorkDirectoryURL.appending(path: "SafeDIManifest.json")
-			try writeManifest(
-				dependencyTreeInputFiles: rootFiles,
+			let outputFiles = try runRootScanner(
+				inputSourcesFile: inputSourcesFile,
+				projectRoot: projectRoot,
 				outputDirectory: outputDirectory,
-				to: manifestFile,
-				relativeTo: projectRoot,
+				manifestFile: manifestFile,
 			)
+			guard !outputFiles.isEmpty else {
+				return []
+			}
 
 			let arguments = [
 				inputSourcesFile.path(percentEncoded: false),

Plugins/SafeDIPrebuiltGenerator/SharedRootScanner.swift

@@ -0,0 +1 @@
+../SharedRootScanner.swift

Plugins/Shared.swift

@@ -112,85 +112,3 @@ extension PackagePlugin.PluginContext {
 		return expectedToolLocation
 	}
 }
-
-/// Find Swift files that contain `@Instantiable(isRoot: true)` declarations.
-func findFilesWithRoots(in swiftFiles: [URL]) -> [URL] {
-	swiftFiles.filter { fileURL in
-		guard let content = try? String(contentsOf: fileURL, encoding: .utf8) else { return false }
-		guard content.contains("isRoot") else { return false }
-		guard let regex = try? Regex(#"@Instantiable\s*\([^)]*isRoot\s*:\s*true[^)]*\)"#) else { return false }
-		// Check each match is not inside a comment or backtick-quoted code span.
-		for match in content.matches(of: regex) {
-			let lineStart = content[content.startIndex..<match.range.lowerBound].lastIndex(of: "\n").map { content.index(after: $0) } ?? content.startIndex
-			let linePrefix = content[lineStart..<match.range.lowerBound]
-			// Skip matches inside single-line comments.
-			if linePrefix.contains("//") { continue }
-			// Skip matches inside backtick-quoted code spans.
-			if linePrefix.contains("`") { continue }
-			return true
-		}
-		return false
-	}
-}
-
-/// Derive unique output filenames for a set of input Swift files.
-/// If two files share the same base name (e.g. `ModuleA/Root.swift` and `ModuleB/Root.swift`),
-/// parent directory components are prepended to disambiguate (e.g. `ModuleA_Root+SafeDI.swift`).
-func outputFileNames(for inputURLs: [URL]) -> [String] {
-	let baseNames = inputURLs.map { $0.deletingPathExtension().lastPathComponent }
-
-	// Count occurrences of each base name.
-	var nameCounts = [String: Int]()
-	for name in baseNames {
-		nameCounts[name, default: 0] += 1
-	}
-
-	return zip(inputURLs, baseNames).map { url, baseName in
-		if nameCounts[baseName, default: 1] > 1 {
-			// Disambiguate by prepending the parent directory name.
-			let parent = url.deletingLastPathComponent().lastPathComponent
-			return "\(parent)_\(baseName)+SafeDI.swift"
-		} else {
-			return "\(baseName)+SafeDI.swift"
-		}
-	}
-}
-
-/// Compute a path string relative to a base directory, for use in the CSV and manifest.
-/// Falls back to the absolute path if the URL is not under the base directory.
-func relativePath(for url: URL, relativeTo base: URL) -> String {
-	let urlPath = url.path(percentEncoded: false)
-	let basePath = base.path(percentEncoded: false).hasSuffix("/")
-		? base.path(percentEncoded: false)
-		: base.path(percentEncoded: false) + "/"
-	if urlPath.hasPrefix(basePath) {
-		return String(urlPath.dropFirst(basePath.count))
-	}
-	return urlPath
-}
-
-/// Write a SafeDIToolManifest JSON file mapping input file paths to output file paths.
-/// Input paths are written relative to `relativeTo` for remote cache compatibility.
-/// Output paths are absolute since they reference the build system's plugin work directory.
-///
-/// Note: The JSON keys here must match the property names in `SafeDIToolManifest` and
-/// `SafeDIToolManifest.InputOutputMap` (in SafeDICore). Plugins cannot import SafeDICore,
-/// so these are duplicated as string literals.
-func writeManifest(
-	dependencyTreeInputFiles: [URL],
-	outputDirectory: URL,
-	to manifestURL: URL,
-	relativeTo base: URL,
-) throws {
-	let fileNames = outputFileNames(for: dependencyTreeInputFiles)
-	var entries = [[String: String]]()
-	for (inputURL, fileName) in zip(dependencyTreeInputFiles, fileNames) {
-		entries.append([
-			"inputFilePath": relativePath(for: inputURL, relativeTo: base),
-			"outputFilePath": outputDirectory.appending(path: fileName).path(percentEncoded: false),
-		])
-	}
-	let manifest = ["dependencyTreeGeneration": entries]
-	let data = try JSONSerialization.data(withJSONObject: manifest, options: [.sortedKeys])
-	try data.write(to: manifestURL)
-}

Plugins/SharedRootScanner.swift

@@ -0,0 +1,52 @@
+// Distributed under the MIT License
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+import Foundation
+
+func writeInputSwiftFilesCSV(
+	_ swiftFiles: [URL],
+	relativeTo base: URL,
+	to inputSourcesFile: URL,
+) throws {
+	try swiftFiles
+		.map { relativePath(for: $0, relativeTo: base) }
+		.joined(separator: ",")
+		.write(
+			to: inputSourcesFile,
+			atomically: true,
+			encoding: .utf8,
+		)
+}
+
+func runRootScanner(
+	inputSourcesFile: URL,
+	projectRoot: URL,
+	outputDirectory: URL,
+	manifestFile: URL,
+) throws -> [URL] {
+	let inputFilePaths = try RootScanner.inputFilePaths(from: inputSourcesFile)
+	let result = try RootScanner().scan(
+		inputFilePaths: inputFilePaths,
+		relativeTo: projectRoot,
+		outputDirectory: outputDirectory,
+	)
+	try result.writeManifest(to: manifestFile)
+	return result.outputFiles
+}