WIP: swift calculate_output_groups

Signed-off-by: Brentley Jones <github@brentleyjones.com>
Signed-off-by: Matt Pennig <mpennig@slack-corp.com>

tools/BUILD

@@ -4,6 +4,7 @@ load("//xcodeproj:defs.bzl", "xcodeproj", "xcschemes")
 load("//xcodeproj/internal:collections.bzl", "flatten", "uniq")
 
 _TOOLS = {
+    "calculate_output_groups": "//tools/calculate_output_groups",
     "files_and_groups": "//tools/generators/files_and_groups",
     "import_indexstores": "//tools/import_indexstores",
     "pbxnativetargets": "//tools/generators/pbxnativetargets",
@@ -51,6 +52,38 @@ _XCSCHEME_DIAGNOSTICS = xcschemes.diagnostics(
 )
 
 _XCSCHEMES = [
+    xcschemes.scheme(
+        name = "calculate_output_groups",
+        profile = xcschemes.profile(
+            launch_target = xcschemes.launch_target(
+                _TOOLS["calculate_output_groups"],
+            ),
+            xcode_configuration = "Release",
+        ),
+        run = xcschemes.run(
+            args = [
+                # colorDiagnostics
+                "NO",
+                # xcodeVersionActual
+                "1520",
+                # nonPreviewObjRoot
+                "/Users/brentley/Library/Developer/Xcode/DerivedData/tools-exxvdkcaoxdlhndlfnwxqvucohsr/Build/Intermediates.noindex",
+                # baseObjRoot
+                "/Users/brentley/Library/Developer/Xcode/DerivedData/tools-exxvdkcaoxdlhndlfnwxqvucohsr/Build/Intermediates.noindex",
+                # buildMarkerFile
+                "/Users/brentley/Library/Developer/Xcode/DerivedData/tools-exxvdkcaoxdlhndlfnwxqvucohsr/Build/Intermediates.noindex/build_marker",
+                # outputGroupPrefixes
+                "bc,bp,bi",
+            ],
+            build_targets = [
+                _TOOLS["calculate_output_groups"],
+            ],
+            diagnostics = _XCSCHEME_DIAGNOSTICS,
+            launch_target = xcschemes.launch_target(
+                _TOOLS["calculate_output_groups"],
+            ),
+        ),
+    ),
     xcschemes.scheme(
         name = "files_and_groups",
         profile = xcschemes.profile(
@@ -561,6 +594,7 @@ xcodeproj(
 filegroup(
     name = "release_files",
     srcs = [
+        "//" + package_name() + "/calculate_output_groups:release_files",
         "//" + package_name() + "/extension_point_identifiers_parser:release_files",
         "//" + package_name() + "/generators:release_files",
         "//" + package_name() + "/import_indexstores:release_files",

tools/calculate_output_groups/Arguments.swift

@@ -0,0 +1,41 @@
+import ArgumentParser
+import Foundation
+
+extension OutputGroupsCalculator {
+    struct Arguments: ParsableArguments {
+        @Argument(
+            help: "Value of the 'XCODE_VERSION_ACTUAL' environment variable."
+        )
+        var xcodeVersionActual: Int
+
+        @Argument(
+            help: """
+Value of the 'OBJROOT' build setting when 'ENABLE_PREVIEWS = NO'.
+""",
+            transform: { URL(fileURLWithPath: $0, isDirectory: true) }
+        )
+        var nonPreviewObjRoot: URL
+
+        @Argument(
+            help: """
+Value of 'nonPreviewObjRoot' when 'INDEX_ENABLE_BUILD_ARENA = NO'.
+""",
+            transform: { URL(fileURLWithPath: $0, isDirectory: true) }
+        )
+        var baseObjRoot: URL
+
+        @Argument(
+            help: """
+Path to a file that has a ctime at or after the start of the build.
+""",
+            transform: { URL(fileURLWithPath: $0, isDirectory: false) }
+        )
+        var buildMarkerFile: URL
+
+        @Argument(
+            help: "Comma seperated list of output group prefixes.",
+            transform: { $0.split(separator: ",").map(String.init) }
+        )
+        var outputGroupPrefixes: [String]
+    }
+}

tools/calculate_output_groups/BUILD

@@ -0,0 +1,64 @@
+load("@build_bazel_rules_apple//apple:apple.bzl", "apple_universal_binary")
+load(
+    "@build_bazel_rules_apple//apple:macos.bzl",
+    "macos_command_line_application",
+)
+load(
+    "@build_bazel_rules_swift//swift:swift.bzl",
+    "swift_binary",
+    "swift_library",
+)
+
+# This target exists to keep configurations the same between the generator
+# and the tests, which makes the Xcode development experience better. If we used
+# `swift_binary` or `apple_universal_binary` in `xcodeproj`, then the
+# `macos_unit_test` transition (which is used to be able to set a minimum os
+# version on the tests) will create slightly different configurations for our
+# `swift_library`s. Maybe https://github.com/bazelbuild/bazel/issues/6526 will
+# fix that for us.
+macos_command_line_application(
+    name = "calculate_output_groups",
+    minimum_os_version = "12.0",
+    visibility = ["//visibility:public"],
+    deps = [":calculate_output_groups.library"],
+)
+
+swift_library(
+    name = "calculate_output_groups.library",
+    srcs = glob(["*.swift"]),
+    module_name = "calculate_output_groups",
+    deps = [
+        "//tools/lib/ToolCommon",
+        "@com_github_apple_swift_argument_parser//:ArgumentParser",
+        "@com_github_michaeleisel_zippyjson//:ZippyJSON",
+    ],
+)
+
+swift_binary(
+    name = "calculate_output_groups_binary",
+    deps = [":calculate_output_groups.library"],
+)
+
+apple_universal_binary(
+    name = "universal_calculate_output_groups",
+    binary = ":calculate_output_groups_binary",
+    forced_cpus = [
+        "x86_64",
+        "arm64",
+    ],
+    minimum_os_version = "12.0",
+    platform_type = "macos",
+    visibility = ["//visibility:public"],
+)
+
+# Release
+
+filegroup(
+    name = "release_files",
+    srcs = [
+        "BUILD.release.bazel",
+        ":universal_calculate_output_groups",
+    ],
+    tags = ["manual"],
+    visibility = ["//:__subpackages__"],
+)

tools/calculate_output_groups/BUILD.release.bazel

@@ -0,0 +1 @@
+exports_files(["universal_calculate_output_groups"])

tools/calculate_output_groups/CalculateOutputGroups.swift

@@ -0,0 +1,31 @@
+import ArgumentParser
+import Darwin
+import ToolCommon
+
+@main
+struct CalculateOutputGroups: AsyncParsableCommand {
+    @Argument(
+        help: "Value of the 'COLOR_DIAGNOSTICS' environment variable.",
+        transform: { $0 == "YES" }
+    )
+    var colorDiagnostics: Bool
+
+    @OptionGroup var arguments: OutputGroupsCalculator.Arguments
+
+    func run() async throws {
+        let logger = DefaultLogger(
+            standardError: StderrOutputStream(),
+            standardOutput: StdoutOutputStream(),
+            colorize: colorDiagnostics
+        )
+
+        let calculator = OutputGroupsCalculator()
+
+        do {
+            try await calculator.calculateOutputGroups(arguments: arguments)
+        } catch {
+            logger.logError(error.localizedDescription)
+            Darwin.exit(1)
+        }
+    }
+}

tools/calculate_output_groups/OutputGroupsCalculator.swift

@@ -0,0 +1,126 @@
+import Foundation
+import ToolCommon
+import ZippyJSON
+
+struct OutputGroupsCalculator {
+    func calculateOutputGroups(arguments: Arguments) async throws {
+        let pifCache = arguments.baseObjRoot
+            .appendingPathComponent("XCBuildData/PIFCache")
+        let projectCache = pifCache.appendingPathComponent("project")
+        let targetCache = pifCache.appendingPathComponent("target")
+
+        let fileManager = FileManager.default
+
+        guard fileManager.fileExists(atPath: projectCache.path) &&
+                fileManager.fileExists(atPath: targetCache.path)
+        else {
+            throw UsageError(message: """
+error: PIFCache (\(pifCache)) doesn't exist. If you manually cleared Derived \
+Data, you need to close and re-open the project for the PIFCache to be created \
+again. Using the "Clean Build Folder" command instead (⇧ ⌘ K) won't trigger \
+this error. If this error still happens after re-opening the project, please \
+file a bug report here: \
+https://github.com/MobileNativeFoundation/rules_xcodeproj/issues/new?template=bug.md
+""")
+        }
+
+        let projectURL = try Self.findProjectURL(in: projectCache)
+        let project = try Self.decodeProject(at: projectURL)
+        let targets =
+            try await Self.decodeTargets(project.targets, in: targetCache)
+
+        dump(targets)
+    }
+
+    static func findProjectURL(in projectCache: URL) throws -> URL {
+        let projectPIFsEnumerator = FileManager.default.enumerator(
+            at: projectCache,
+            includingPropertiesForKeys: [.contentModificationDateKey],
+            options: [
+                .skipsHiddenFiles,
+                .skipsPackageDescendants,
+                .skipsSubdirectoryDescendants,
+            ]
+        )!
+
+        var newestProjectPIF: URL?
+        var newestProjectPIFDate = Date.distantPast
+        for case let projectPIF as URL in projectPIFsEnumerator {
+            guard let resourceValues = try? projectPIF.resourceValues(
+                forKeys: [.contentModificationDateKey]
+            ), let modificationDate = resourceValues.contentModificationDate
+            else {
+                continue
+            }
+
+            // TODO: The modification date is in the filename, should we use
+            // that instead?
+            if modificationDate > newestProjectPIFDate {
+                newestProjectPIF = projectPIF
+                newestProjectPIFDate = modificationDate
+            }
+        }
+
+        guard let projectPIF = newestProjectPIF else {
+            throw UsageError(message: """
+error: Couldn't find a Project PIF at "\(projectCache)". Please file a bug \
+report here: https://github.com/MobileNativeFoundation/rules_xcodeproj/issues/new?template=bug.md
+""")
+        }
+
+        return projectPIF
+    }
+
+    static func decodeProject(at url: URL) throws -> ProjectPIF {
+        let decoder = ZippyJSONDecoder()
+        return try decoder.decode(ProjectPIF.self, from: Data(contentsOf: url))
+    }
+
+    static func decodeTargets(
+        _ targets: [String],
+        in targetCache: URL
+    ) async throws -> [TargetPIF] {
+        return try await withThrowingTaskGroup(
+            of: TargetPIF.self,
+            returning: [TargetPIF].self
+        ) { group in
+            for target in targets {
+                group.addTask {
+                    let url =
+                        targetCache.appendingPathComponent("\(target)-json")
+                    let decoder = ZippyJSONDecoder()
+                    return try decoder
+                        .decode(TargetPIF.self, from: Data(contentsOf: url))
+                }
+            }
+
+            var targetPIFs: [TargetPIF] = []
+            for try await target in group {
+                targetPIFs.append(target)
+            }
+
+            return targetPIFs
+        }
+    }
+}
+
+struct ProjectPIF: Decodable {
+    let targets: [String]
+}
+
+struct TargetPIF: Decodable {
+    struct BuildConfiguration: Decodable {
+        let name: String
+        let buildSettings: [String: String]
+    }
+
+    let guid: String
+    let buildConfigurations: [BuildConfiguration]
+}
+
+struct Target {
+    let label: String
+
+    // Maps Platform Name -> [Target ID]
+    let targetIds: [String: [String]]
+}