use existing APIs to call Python

Author: charles-zablit

Sources/SwiftDriver/Driver/Driver.swift

@@ -865,6 +865,14 @@ public struct Driver {
     if case .subcommand = try Self.invocationRunMode(forArgs: args).mode {
       throw Error.subcommandPassedToDriver
     }
+
+    #if os(Windows)
+      if args[1] == "-repl" {  // a `-` gets automatically added to `swift repl`.
+        try Driver.checkIfMatchingPythonArch(
+          executor: executor, env: env, diagnosticsEngine: diagnosticsEngine)
+      }
+    #endif
+
     var args = args
     if let additional = env["ADDITIONAL_SWIFT_DRIVER_FLAGS"] {
       args.append(contentsOf: additional.components(separatedBy: " "))
@@ -1426,9 +1434,6 @@ extension Driver {
     if firstArg == "repl" {
         updatedArgs.remove(at: 1)
         updatedArgs.append("-repl")
-        #if os(Windows)
-        checkIfMatchingPythonArch()
-        #endif
         return (.normal(isRepl: true), updatedArgs)
     }
 
@@ -1446,40 +1451,33 @@ extension Driver {
   /// install an x86 version of Python, they will get acryptic error message
   /// when running lldb (`0xC000007B`). Calling this function before invoking
   /// lldb gives them a warning to help troublshoot the issue.
-  private static func checkIfMatchingPythonArch() {
+  public static func checkIfMatchingPythonArch(
+    executor: DriverExecutor, env: [String: String], diagnosticsEngine: DiagnosticsEngine
+  ) throws {
     #if arch(arm64)
-    let arch = "arm64"
+      let toolchainArchitecture = "arm64"
     #elseif arch(x86_64)
-    let arch = "amd64"
+      let toolchainArchitecture = "amd64"
     #elseif arch(x86)
-    let arch = "x86"
+      let toolchainArchitecture = "x86"
     #else
-    return;
+      return;
     #endif
-    let process = Process()
-    process.executableURL = URL(fileURLWithPath: "C:\\Windows\\System32\\cmd.exe")
-    process.arguments = ["/c", "python.exe", "-c", "import platform; print(platform.machine())"]
-
-    let pipe = Pipe()
-    process.standardOutput = pipe
-    do {
-        try process.run()
-        process.waitUntilExit()
-
-        let data = pipe.fileHandleForReading.readDataToEndOfFile()
-        guard let output = String(data: data, encoding: .utf8) else {
-          return;
-        }
-        if !output.lowercased().contains(arch) {
-          stderrStream.send("There is an architecture mismatch between the installed toolchain and the resolved Python's architecture:\n")
-          stderrStream.send("Toolchain: \(arch)\n")
-          stderrStream.send("Python: \(output)\n")
-        }
-    } catch {
-      stderrStream.flush()
-      return
+    let pythonArchitecture = try executor.checkNonZeroExit(
+      args: "python.exe", "-c", "import platform; print(platform.machine())",
+      environment: env
+    ).trimmingCharacters(in: .whitespacesAndNewlines)
+      .lowercased()
+
+    if !pythonArchitecture.contains(toolchainArchitecture) {
+      diagnosticsEngine.emit(
+        .warning(
+          """
+          There is an architecture mismatch between the installed toolchain and the resolved Python's architecture:
+          Toolchain: \(toolchainArchitecture)
+          Python: \(pythonArchitecture)
+          """))
     }
-    stderrStream.flush()
   }
 }