gm self-test: make sure we report failures in individual rendering modes

gm/gmmain.cpp

Index: gm/gmmain.cpp
===================================================================
--- gm/gmmain.cpp	(revision 8160)
+++ gm/gmmain.cpp	(working copy)
@@ -194,6 +194,7 @@
         // Set default values of member variables, which tool_main()
         // may override.
         fUseFileHierarchy = false;
+        fSimulatePipePlaybackFailure = false;

[borenet, 2013/03/14 18:48:21]

I'm not sure I like the technique of baking test code directly into the
application itself...

[epoger, 2013/03/14 18:57:12]

It rubs me the wrong way too, but I couldn't think of a better way of validating
the behavior.  Any ideas?

Adding Ravi in CC... back in TvAds, I could have done this by mocking out some
resource in such a way that it returned failure.  I can't figure out an
analogous approach here, but maybe there is one...

[borenet, 2013/03/14 19:02:21]

Yeah, I guess there's not a good way to force this to fail.  It might be better
if this were behind a #ifdef SELF_TEST thing, or even only included in debug
builds.

[rmistry, 2013/03/14 19:47:34]

Sorry, I may have been able to help for Java or Python but I have no experience
with mocking in C++.

[epoger, 2013/03/14 22:36:26]

I'd rather not require a compile-time flag, because that would require the gm
self-test to compile a special version of the code, which seems like both a
hassle and an opportunity for gm to behave different in the "real world" than it
does in test.

I don't think it's so bad to have this command-line option... the code to
implement it is very tight, and anybody who specifies it knows what they will
get!

[borenet, 2013/03/15 20:15:53]

Fair enough.

         fMismatchPath = NULL;
     }
 
@@ -261,8 +262,9 @@
             return;
         }
 
-        FailRec& rec = fFailedTests.push_back(make_name(
-            name.c_str(), renderModeDescriptor));
+        SkString completeName = name;
+        completeName.append(renderModeDescriptor);

[epoger, 2013/03/14 17:22:19]

fixing a minor discrepancy revealed by this test

+        FailRec& rec = fFailedTests.push_back(completeName);
         rec.fIsPixelError =
             (kEmptyErrorBitfield != (errorType & kImageMismatch_ErrorBitmask));
     }
@@ -905,7 +907,9 @@
             SkGPipeWriter writer;
             SkCanvas* pipeCanvas = writer.startRecording(
               &pipeController, gPipeWritingFlagCombos[i].flags);
-            invokeGM(gm, pipeCanvas, false, false);
+            if (!this->fSimulatePipePlaybackFailure) {
+                invokeGM(gm, pipeCanvas, false, false);
+            }
             complete_bitmap(&bitmap);
             writer.endRecording();
             SkString string("-pipe");
@@ -951,6 +955,7 @@
     //
 
     bool fUseFileHierarchy;
+    bool fSimulatePipePlaybackFailure;
 
     const char* fMismatchPath;
 
@@ -1054,6 +1059,7 @@
 "    [--resourcePath|-i <path>]: directory that stores image resources\n"
 "    [--nortree]: Do not exercise the R-Tree variant of SkPicture\n"
 "    [--noserialize]: do not exercise SkPicture serialization & deserialization\n"
+"    [--simulatePipePlaybackFailure]: simulate a rendering failure in pipe mode only\n"
 "    [--tiledPipe]: Exercise tiled SkGPipe replay\n"
 "    [--notileGrid]: Do not exercise the tile grid variant of SkPicture\n"
 "    [--tileGridReplayScales <scales>]: Comma separated list of floating-point scale\n"
@@ -1320,6 +1326,8 @@
             doSerialize = true;
         } else if (strcmp(*argv, "--noserialize") == 0) {
             doSerialize = false;
+        } else if (strcmp(*argv, "--simulatePipePlaybackFailure") == 0) {
+            gmmain.fSimulatePipePlaybackFailure = true;
         } else if (strcmp(*argv, "--tiledPipe") == 0) {
             doTiledPipe = true;
         } else if (!strcmp(*argv, "--verbose") || !strcmp(*argv, "-v")) {