Make DM fail if no configs were successfully created

dm/DM.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "CrashHandler.h"
 #include "DMJsonWriter.h"
 #include "DMSrcSink.h"
@@ skipping 905 matching lines @@
     }
 
 #ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK
     VIA("androidsdk", ViaAndroidSDK, wrapped);
 #endif
 
 #undef VIA
     return nullptr;
 }
 
-static void gather_sinks() {
+static bool gather_sinks() {
     SkCommandLineConfigArray configs;
     ParseConfigs(FLAGS_config, &configs);
     for (int i = 0; i < configs.count(); i++) {
         const SkCommandLineConfig& config = *configs[i];
         Sink* sink = create_sink(&config);
         if (sink == nullptr) {
             info("Skipping config %s: Don't understand '%s'.\n", config.getTag().c_str(),
                  config.getTag().c_str());
             continue;
         }
 
         const SkTArray<SkString>& parts = config.getViaParts();
         for (int j = parts.count(); j-- > 0;) {
             const SkString& part = parts[j];
             Sink* next = create_via(part, sink);
             if (next == nullptr) {
                 info("Skipping config %s: Don't understand '%s'.\n", config.getTag().c_str(),
                      part.c_str());
                 delete sink;
                 sink = nullptr;
                 break;
             }
             sink = next;
         }
         if (sink) {
             push_sink(config, sink);
         }
     }
+
+    // If no configs were requested (just running tests, perhaps?), then we're okay.
+    // Otherwise, make sure that at least one sink was constructed correctly. This catches
+    // the case of bots without a GPU being assigned GPU configs.
+    return (configs.count() == 0) || (gSinks.count() > 0);
 }
 
 static bool dump_png(SkBitmap bitmap, const char* path, const char* md5) {
     const int w = bitmap.width(),
               h = bitmap.height();
 
     sk_sp<SkData> encodedBitmap = sk_tools::encode_bitmap_for_png(bitmap);
     if (encodedBitmap.get() == nullptr) {
         return false;
     }
@@ skipping 351 matching lines @@
         if (!testResource.isValid()) {
             info("Some resources are missing.  Do you need to set --resourcePath?\n");
         }
     }
     gather_gold();
     gather_uninteresting_hashes();
 
     if (!gather_srcs()) {
         return 1;
     }
-    gather_sinks();
+    if (!gather_sinks()) {
+        return 1;
+    }
     gather_tests();
     gPending = gSrcs.count() * gSinks.count() + gParallelTests.count() + gSerialTests.count();
     info("%d srcs * %d sinks + %d tests == %d tasks",
          gSrcs.count(), gSinks.count(), gParallelTests.count() + gSerialTests.count(), gPending);
     SkAutoTDelete<SkThread> statusThread(start_status_thread());
 
     // Kick off as much parallel work as we can, making note of any serial work we'll need to do.
     SkTaskGroup parallel;
     SkTArray<Task> serial;
 
@@ skipping 106 matching lines @@
 #endif
 }
 } // namespace skiatest
 
 #if !defined(SK_BUILD_FOR_IOS)
 int main(int argc, char** argv) {
     SkCommandLineFlags::Parse(argc, argv);
     return dm_main();
 }
 #endif