Add support for runOncePerArchitecture (#950)

Add changelog and small change

Fix build error

CHANGELOG.md

@@ -7,6 +7,7 @@
 - Add `useBaseInternationalization` to Project Spec Options to opt out of Base Internationalization. [#961](https://github.com/yonaskolb/XcodeGen/pull/961) @liamnichols
 - More detailed error message with method arguments. [#990](https://github.com/yonaskolb/XcodeGen/pull/990) @bannzai
 - Added `basedOnDependencyAnalysis` to Project Spec Build Script to be able to choose not to skip the script. [#992](https://github.com/yonaskolb/XcodeGen/pull/992) @myihsan
+- Add `BuildRule.runOncePerArchitecture` to allow running build rules once per architecture. [#950](https://github.com/yonaskolb/XcodeGen/pull/950) @sascha
 
 #### Changed
 - **Breaking**: Info.plists with custom prefixes are no longer added to the Copy Bundle Resources build phase [#945](https://github.com/yonaskolb/XcodeGen/pull/945) @anivaros

Docs/ProjectSpec.md

@@ -605,6 +605,7 @@ targets:
 - [ ] **name**: **String** - The name of a build rule. Defaults to `Build Rule`
 - [ ] **outputFiles**: **[String]** - The list of output files
 - [ ] **outputFilesCompilerFlags**: **[String]** - The list of compiler flags to apply to the output files
+- [ ] **runOncePerArchitecture**: **Bool** - a boolean that indicates if this rule should run once per architecture. This defaults to true
 
 ```yaml
 targets:
@@ -619,6 +620,7 @@ targets:
         compilerSpec: com.apple.xcode.tools.swift.compiler
         outputFiles:
           - $(SRCROOT)/Generated.swift
+        runOncePerArchitecture: false
 ```
 
 ###  Target Scheme

Sources/ProjectSpec/BuildRule.swift

@@ -5,6 +5,7 @@ public struct BuildRule: Equatable {
 
     public static let scriptCompilerSpec = "com.apple.compilers.proxy.script"
     public static let filePatternFileType = "pattern.proxy"
+    public static let runOncePerArchitectureDefault = true
 
     public enum FileType: Equatable {
         case type(String)
@@ -49,13 +50,22 @@ public struct BuildRule: Equatable {
     public var outputFiles: [String]
     public var outputFilesCompilerFlags: [String]
     public var name: String?
+    public var runOncePerArchitecture: Bool
 
-    public init(fileType: FileType, action: Action, name: String? = nil, outputFiles: [String] = [], outputFilesCompilerFlags: [String] = []) {
+    public init(
+        fileType: FileType, 
+        action: Action, 
+        name: String? = nil, 
+        outputFiles: [String] = [], 
+        outputFilesCompilerFlags: [String] = [], 
+        runOncePerArchitecture: Bool = runOncePerArchitectureDefault
+    ) {
         self.fileType = fileType
         self.action = action
         self.name = name
         self.outputFiles = outputFiles
         self.outputFilesCompilerFlags = outputFilesCompilerFlags
+        self.runOncePerArchitecture = runOncePerArchitecture
     }
 }
 
@@ -78,6 +88,7 @@ extension BuildRule: JSONObjectConvertible {
         outputFiles = jsonDictionary.json(atKeyPath: "outputFiles") ?? []
         outputFilesCompilerFlags = jsonDictionary.json(atKeyPath: "outputFilesCompilerFlags") ?? []
         name = jsonDictionary.json(atKeyPath: "name")
+        runOncePerArchitecture = jsonDictionary.json(atKeyPath: "runOncePerArchitecture") ?? BuildRule.runOncePerArchitectureDefault
     }
 }
 
@@ -103,6 +114,10 @@ extension BuildRule: JSONEncodable {
             dict["script"] = string
         }
 
+        if runOncePerArchitecture != BuildRule.runOncePerArchitectureDefault {
+            dict["runOncePerArchitecture"] = runOncePerArchitecture
+        }
+
         return dict
     }
 }

Sources/XcodeGenKit/PBXProjGenerator.swift

@@ -1150,7 +1150,8 @@ public class PBXProjGenerator {
                     name: buildRule.name ?? "Build Rule",
                     outputFiles: buildRule.outputFiles,
                     outputFilesCompilerFlags: buildRule.outputFilesCompilerFlags,
-                    script: buildRule.action.script
+                    script: buildRule.action.script,
+                    runOncePerArchitecture: buildRule.runOncePerArchitecture
                 )
             )
         }

Tests/ProjectSpecTests/ProjectSpecTests.swift

@@ -414,12 +414,14 @@ class ProjectSpecTests: XCTestCase {
                                                                            action: .script("pre_process_swift.py"),
                                                                            name: "My Build Rule",
                                                                            outputFiles: ["$(SRCROOT)/Generated.swift"],
-                                                                           outputFilesCompilerFlags: ["foo"]),
+                                                                           outputFilesCompilerFlags: ["foo"],
+                                                                           runOncePerArchitecture: false),
                                                                  BuildRule(fileType: .type("sourcecode.swift"),
                                                                            action: .compilerSpec("com.apple.xcode.tools.swift.compiler"),
                                                                            name: nil,
                                                                            outputFiles: ["bar"],
-                                                                           outputFilesCompilerFlags: ["foo"])],
+                                                                           outputFilesCompilerFlags: ["foo"],
+                                                                           runOncePerArchitecture: true)],
                                                     scheme: TargetScheme(testTargets: [Scheme.Test.TestTarget(targetReference: "test target",
                                                                                                               randomExecutionOrder: false,
                                                                                                               parallelizable: false)],