[test] DependenciesScanner: running shell commands via a python script instead from Swift

Running shell commands using Swift in simulator tests is hard. We change the mechanism so that
BuildModulesFromGraph.swift prints command line arguments and a simple python script
picks these arguments and actually runs the command.

Author: nkcsgexi

test/ScanDependencies/Inputs/BuildModulesFromGraph.swift

@@ -36,19 +36,11 @@ func findModuleBuildingCommand(_ moduleName: String) -> [String]? {
   return nil
 }
 
-func run(command: String, arguments: [String] = []) -> Int32 {
-  let process = Process()
-  process.launchPath = command
-  process.arguments = arguments
-  let outputPipe = Pipe()
-  process.standardOutput = outputPipe
-  process.launch()
-  process.waitUntilExit()
-  return process.terminationStatus
-}
-
 if let command = findModuleBuildingCommand(moduleName) {
-  exit(run(command: swiftPath, arguments: command))
+  var result = swiftPath
+  command.forEach { result += " \($0)"}
+  print(result)
+  exit(0)
 } else {
   fatalError("cannot find module building commands for \(moduleName)")
 }

test/ScanDependencies/Inputs/CommandRunner.py

@@ -0,0 +1,7 @@
+#!/usr/bin/python
+
+import subprocess
+import sys
+
+for line in sys.stdin:
+    subprocess.check_call(line.split())

test/ScanDependencies/module_deps.swift

@@ -22,19 +22,19 @@
 // RUN: %target-build-swift %S/Inputs/ModuleDependencyGraph.swift %t/BuildModules/main.swift -o %t/ModuleBuilder
 // RUN: %target-codesign %t/ModuleBuilder
 
-// RUN: %target-run %t/ModuleBuilder %t/deps.json %swift-path A.pcm
+// RUN: %target-run %t/ModuleBuilder %t/deps.json %swift-path A.pcm | %S/Inputs/CommandRunner.py
 // RUN: ls %t/clang-module-cache/A-*.pcm
-// RUN: %target-run %t/ModuleBuilder %t/deps.json %swift-path B.pcm
+// RUN: %target-run %t/ModuleBuilder %t/deps.json %swift-path B.pcm | %S/Inputs/CommandRunner.py
 // RUN: ls %t/clang-module-cache/B-*.pcm
-// RUN: %target-run %t/ModuleBuilder %t/deps.json %swift-path C.pcm
+// RUN: %target-run %t/ModuleBuilder %t/deps.json %swift-path C.pcm | %S/Inputs/CommandRunner.py
 // RUN: ls %t/clang-module-cache/C-*.pcm
-// RUN: %target-run %t/ModuleBuilder %t/deps.json %swift-path A.swiftmodule
+// RUN: %target-run %t/ModuleBuilder %t/deps.json %swift-path A.swiftmodule | %S/Inputs/CommandRunner.py
 // RUN: ls %t/clang-module-cache/A-*.swiftmodule
-// RUN: %target-run %t/ModuleBuilder %t/deps.json %swift-path E.swiftmodule
+// RUN: %target-run %t/ModuleBuilder %t/deps.json %swift-path E.swiftmodule | %S/Inputs/CommandRunner.py
 // RUN: ls %t/clang-module-cache/E-*.swiftmodule
-// RUN: %target-run %t/ModuleBuilder %t/deps.json %swift-path F.swiftmodule
+// RUN: %target-run %t/ModuleBuilder %t/deps.json %swift-path F.swiftmodule | %S/Inputs/CommandRunner.py
 // RUN: ls %t/clang-module-cache/F-*.swiftmodule
-// RUN: %target-run %t/ModuleBuilder %t/deps.json %swift-path G.swiftmodule
+// RUN: %target-run %t/ModuleBuilder %t/deps.json %swift-path G.swiftmodule | %S/Inputs/CommandRunner.py
 // RUN: ls %t/clang-module-cache/G-*.swiftmodule
 
 // REQUIRES: executable_test