Add support for building Swift SDKs for armv7 with target Swift toolchain or docker container

Sources/SwiftSDKGenerator/Generator/SwiftSDKGenerator+Copy.swift

@@ -73,6 +73,11 @@ extension SwiftSDKGenerator {
         // But not in all containers, so don't fail if it does not exist.
         if case .ubuntu = targetDistribution {
           subpaths += [("\(targetTriple.archName)-linux-gnu", false)]
+
+          // Custom subpath for armv7
+          if targetTriple.archName == "armv7" {
+            subpaths += [("arm-linux-gnueabihf", false)]
+          }
         }
 
         for (subpath, failIfNotExists) in subpaths {
@@ -104,13 +109,16 @@ extension SwiftSDKGenerator {
   func copyTargetSwift(from distributionPath: FilePath, sdkDirPath: FilePath) async throws {
     logger.info("Copying Swift core libraries for the target triple into Swift SDK bundle...")
 
-    for (pathWithinPackage, pathWithinSwiftSDK) in [
-      ("lib/swift", sdkDirPath.appending("usr/lib")),
-      ("lib/swift_static", sdkDirPath.appending("usr/lib")),
-      ("lib/clang", sdkDirPath.appending("usr/lib")),
-      ("include", sdkDirPath.appending("usr")),
+    for (pathWithinPackage, pathWithinSwiftSDK, ignoreIfMissing) in [
+      ("lib/swift", sdkDirPath.appending("usr/lib"), false),
+      ("lib/swift_static", sdkDirPath.appending("usr/lib"), false),
+      ("lib/clang", sdkDirPath.appending("usr/lib"), true),
+      ("include", sdkDirPath.appending("usr"), false),
     ] {
-      try await rsync(from: distributionPath.appending(pathWithinPackage), to: pathWithinSwiftSDK)
+      try await rsync(
+        from: distributionPath.appending(pathWithinPackage),
+        to: pathWithinSwiftSDK, ignoreIfMissing: ignoreIfMissing
+      )
     }
   }
 }
@@ -120,6 +128,7 @@ extension Triple {
     switch self.archName {
       case "x86_64": return "/lib64/ld-linux-x86-64.so.2"
       case "aarch64": return "/lib/ld-linux-aarch64.so.1"
+      case "armv7": return "/lib/ld-linux-armhf.so.3"
       default: fatalError("unsupported architecture \(self.archName)")
     }
   }

Sources/SwiftSDKGenerator/Generator/SwiftSDKGenerator+Entrypoint.swift

@@ -26,6 +26,7 @@ public extension Triple.Arch {
     case .aarch64: return "arm64"
     case .x86_64: return "amd64"
     case .wasm32: return "wasm32"
+    case .arm: return "armhf"
     default: fatalError("\(self) is not supported yet")
     }
   }

Sources/SwiftSDKGenerator/Generator/SwiftSDKGenerator.swift

@@ -158,9 +158,10 @@ public actor SwiftSDKGenerator {
     try Data(contentsOf: URL(fileURLWithPath: path.string))
   }
 
-  func rsync(from source: FilePath, to destination: FilePath) async throws {
+  func rsync(from source: FilePath, to destination: FilePath, ignoreIfMissing: Bool = false) async throws {
     try self.createDirectoryIfNeeded(at: destination)
-    try await Shell.run("rsync -a \(source) \(destination)", shouldLogCommands: self.isVerbose)
+    let ignoreMissingArgs = ignoreIfMissing ? "--ignore-missing-args" : ""
+    try await Shell.run("rsync -a \(ignoreMissingArgs) \(source) \(destination)", shouldLogCommands: self.isVerbose)
   }
 
   func rsyncContents(from source: FilePath, to destination: FilePath) async throws {

Sources/SwiftSDKGenerator/PlatformModels/Triple.swift

@@ -33,6 +33,7 @@ extension Triple.Arch {
     case .aarch64: return "aarch64"
     case .x86_64: return "x86_64"
     case .wasm32: return "wasm32"
+    case .arm: return "arm"
     default: fatalError("\(self) is not supported yet")
     }
   }

Sources/SwiftSDKGenerator/SwiftSDKRecipes/LinuxRecipe.swift

@@ -158,7 +158,7 @@ public struct LinuxRecipe: SwiftSDKRecipe {
       self.linuxDistribution
         .release
     )_\(
-      self.mainTargetTriple.arch!.linuxConventionName
+      self.mainTargetTriple.archName
     )
     """
   }
@@ -217,6 +217,12 @@ public struct LinuxRecipe: SwiftSDKRecipe {
     engine: QueryEngine,
     httpClient client: some HTTPClientProtocol
   ) async throws -> SwiftSDKProduct {
+    if self.linuxDistribution.name == .rhel && self.mainTargetTriple.archName == "armv7" {
+      throw GeneratorError.distributionDoesNotSupportArchitecture(
+        self.linuxDistribution, targetArchName: self.mainTargetTriple.archName
+      )
+    }
+
     let sdkDirPath = self.sdkDirPath(paths: generator.pathsConfiguration)
     if !generator.isIncremental {
       try await generator.removeRecursively(at: sdkDirPath)

Sources/SwiftSDKGenerator/SystemUtils/GeneratorError.swift

@@ -22,6 +22,7 @@ enum GeneratorError: Error {
   case unknownCPUArchitecture(String)
   case unknownLLDVersion(String)
   case distributionSupportsOnlyDockerGenerator(LinuxDistribution)
+  case distributionDoesNotSupportArchitecture(LinuxDistribution, targetArchName: String)
   case fileDoesNotExist(FilePath)
   case fileDownloadFailed(URL, String)
   case ubuntuPackagesDecompressionFailure
@@ -50,6 +51,10 @@ extension GeneratorError: CustomStringConvertible {
       Target Linux distribution \(linuxDistribution) supports Swift SDK generation only when `--with-docker` flag is \
       passed.
       """
+    case let .distributionDoesNotSupportArchitecture(linuxDistribution, targetArchName):
+      return """
+      Target Linux distribution \(linuxDistribution) does not support the target architecture: \(targetArchName)
+      """
     case let .fileDoesNotExist(filePath):
       return "Expected to find a file at path `\(filePath)`."
     case let .fileDownloadFailed(url, status):