Extend precompilation test to Mac. Attempt to fix for host MIPS.

tests/standalone/precompilation_test.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 // Test generating and running a simple precompiled snapshot of this script.
 
 import 'dart:io';
 
 main(List args) {
-  if (!Platform.isLinux) {
-    print("Linux only test");
-    return;
-  }
   if (args.length > 0 && args[0] == "--hello") {
     print("Hello");
     return;
   }
+
+  var cc, cc_flags, shared, libname;
+  if (Platform.isLinux) {
+    cc = 'gcc';
+    shared = '-shared';
+    libname = 'libprecompiled.so';
+  } else if (Platform.isMacOS) {
+    cc = 'clang';
+    shared = '-dynamiclib';
+    libname = 'libprecompiled.dylib';
+  } else {
+    print("Test only supports Linux and Mac");
+    return;
+  }
+
+  if (Platform.version.contains("x64")) {
+    cc_flags = "-m64";
+  } else if (Platform.version.contains("simarm64")) {
+    cc_flags = "-m64";
+  } else if (Platform.version.contains("simarm")) {
+    cc_flags = "-m32";
+  } else if (Platform.version.contains("simmips")) {
+    cc_flags = "-m32";
+  } else if (Platform.version.contains("arm")) {
+    cc_flags = "";
+  } else if (Platform.version.contains("mips")) {
+    cc_flags = "-EL";
+  } else {
+    print("Architecture not supported: ${Platform.version}");
+    return;
+  }
+
   var dart_executable =
       Directory.current.path + Platform.pathSeparator + Platform.executable;
   Directory tmp;
   try {
     tmp = Directory.current.createTempSync("temp_precompilation_test");
     var result = Process.runSync(
        "${dart_executable}_no_snapshot",
        ["--gen-precompiled-snapshot", Platform.script.path],
        workingDirectory: tmp.path);
     if (result.exitCode != 0) {
       print(result.stdout);
       print(result.stderr);
       throw "Snapshot generation failed.";
     }
 
     // Check if gcc is present, and skip test if it is not.
     try {
       result = Process.runSync(
-          "gcc",
+          cc,
           ["--version"],
           workingDirectory: tmp.path);
       if (result.exitCode != 0) {
-        throw "gcc --version failed.";
+        throw "$cc --version failed.";
       }
     } catch(e) {
-      print("Skipping test because gcc is not present: $e");
+      print("Skipping test because $cc is not present: $e");
       return;
     }
 
-    // Detect if we're running a 32- or 64-bit VM.
-    result = Process.runSync( "file", [dart_executable]);
-    if (result.exitCode != 0) {
-      print(result.stdout);
-      print(result.stderr);
-      throw "'file $dart_executable' failed.";
-    }
-    var m_option = result.stdout.contains("32-bit") ? "-m32" : "-m64";
-
     result = Process.runSync(
-        "gcc",
-        ["-shared", m_option, "-o", "libprecompiled.so", "precompiled.S"],
+        cc,
+        [shared, cc_flags, "-o", libname, "precompiled.S"],
         workingDirectory: tmp.path);
     if (result.exitCode != 0) {
       print(result.stdout);
       print(result.stderr);
       throw "Shared library creation failed!";
     }
+
+    var ld_library_path = new String.fromEnvironment("LD_LIBRARY_PATH");
+    ld_library_path = "${ld_library_path}:${tmp.path}";
+
     result = Process.runSync(
        "${dart_executable}",
        ["--run-precompiled-snapshot", "ignored_script", "--hello"],
-       workingDirectory: tmp.path);
+       workingDirectory: tmp.path,
+       environment: {"LD_LIBRARY_PATH": ld_library_path});
     if (result.exitCode != 0) {
       print(result.stdout);
       print(result.stderr);
       throw "Precompiled binary failed.";
     }
     print(result.stdout);
     if (result.stdout != "Hello\n") {
       throw "Precompiled binary output mismatch.";
     }
   } finally {
     tmp?.deleteSync(recursive: true);
   }
 }