WIP: swift calculate_output_groups

Signed-off-by: Matt Pennig <mpennig@slack-corp.com>

tools/calculate_output_groups/BUILD

@@ -18,7 +18,7 @@ load(
 # fix that for us.
 macos_command_line_application(
     name = "calculate_output_groups",
-    minimum_os_version = "12.0",
+    minimum_os_version = "13.0",
     visibility = ["//visibility:public"],
     deps = [":calculate_output_groups.library"],
 )
@@ -46,7 +46,7 @@ apple_universal_binary(
         "x86_64",
         "arm64",
     ],
-    minimum_os_version = "12.0",
+    minimum_os_version = "13.0",
     platform_type = "macos",
     visibility = ["//visibility:public"],
 )

tools/calculate_output_groups/CalculateOutputGroups.swift

@@ -1,5 +1,6 @@
 import ArgumentParser
 import Darwin
+import Foundation
 import ToolCommon
 
 @main

tools/calculate_output_groups/Errors.swift

@@ -0,0 +1,32 @@
+import ToolCommon
+
+extension UsageError {
+    static func buildMarker(_ path: String) -> Self {
+        .init(message: """
+error: Build marker (\(path)) doesn't exist. If you manually cleared Derived \
+Data, you need to close and re-open the project for the file 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
+""")
+    }
+
+    static func pifCache(_ path: String) -> Self {
+        .init(message: """
+error: PIFCache (\(path)) 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
+""")
+    }
+
+    static func buildRequest(_ path: String) -> Self {
+        .init(message: """
+error: Couldn't find a build-request.json file inside \(path)". Please file a bug \
+report here: https://github.com/MobileNativeFoundation/rules_xcodeproj/issues/new?template=bug.md
+""")
+    }
+}

tools/calculate_output_groups/Models.swift

@@ -0,0 +1,79 @@
+enum PIF {
+    struct Project: Decodable {
+        let targets: [String]
+    }
+
+    struct Target: Decodable {
+        struct BuildConfiguration: Decodable {
+            let name: String
+            let buildSettings: [String: String]
+        }
+
+        let guid: String
+        let buildConfigurations: [BuildConfiguration]
+    }
+}
+
+struct BuildRequest: Decodable {
+    let command: String = "build" // TODO: support other commands (e.g. "buildFiles")
+    let configurationName: String
+    let configuredTargets: [String]
+    let platform: String
+
+    enum Root: CodingKey {
+        case configuredTargets
+        case parameters
+
+        enum ConfiguredTargets: CodingKey {
+            case guid
+        }
+        enum Parameters: CodingKey {
+            case activeRunDestination
+            case configurationName
+
+            enum ActiveRunDestination: CodingKey {
+                case platform
+            }
+        }
+    }
+
+    init(from decoder: Decoder) throws {
+        let root = try decoder.container(keyedBy: Root.self)
+        let parameters = try root.nestedContainer(keyedBy: Root.Parameters.self, forKey: .parameters)
+
+        // configurationName
+        self.configurationName = try parameters.decode(String.self, forKey: .configurationName)
+
+        // configuredTargets
+        var configuredTargets = try root.nestedUnkeyedContainer(forKey: .configuredTargets)
+        var decodedTargets = [String]()
+        while !configuredTargets.isAtEnd {
+            let target = try configuredTargets.nestedContainer(keyedBy: Root.ConfiguredTargets.self)
+            decodedTargets.append(try target.decode(String.self, forKey: .guid))
+        }
+        self.configuredTargets = decodedTargets
+
+        // platform
+        let activeRunDestination = try parameters.nestedContainer(keyedBy: Root.Parameters.ActiveRunDestination.self, forKey: .activeRunDestination)
+        self.platform = try activeRunDestination.decode(String.self, forKey: .platform)
+    }
+}
+
+enum Output {
+    typealias Map = [String: Target]
+
+    struct Target: Codable {
+        struct Config: Codable {
+            struct Settings: Codable {
+                let base: [String]
+                var platforms: [String: Optional<[String]>]
+            }
+
+            let build: Settings?
+            let buildFiles: Settings?
+        }
+
+        let label: String
+        let configs: [String: Config]
+    }
+}