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 {
     logGenerationStep("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

@@ -160,9 +160,10 @@ 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

@@ -152,7 +152,7 @@ public struct LinuxRecipe: SwiftSDKRecipe {
       self.linuxDistribution
         .release
     )_\(
-      self.mainTargetTriple.arch!.linuxConventionName
+      self.mainTargetTriple.archName
     )
     """
   }