first draft of error checking / reporting API

tests/ErrorTest.cpp

Index: tests/ErrorTest.cpp
diff --git a/tests/ErrorTest.cpp b/tests/ErrorTest.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..f198c038058d769bf3a61041a508d7066ebe938e
--- /dev/null
+++ b/tests/ErrorTest.cpp
@@ -0,0 +1,61 @@
+
+/*
+ * 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 "Test.h"
+#include "SkError.h"
+#include "SkPath.h"
+#include "SkRect.h"
+
+#define CHECK(errcode) REPORTER_ASSERT( reporter, (err = SkGetLastError()) == kError_##errcode); \

[scroggo, 2013/04/08 19:24:53]

Minor nit:
I find macros to be more readable if the '\'s line up.

[humper, 2013/04/08 19:43:23]

Done.

+                       if (err != kError_NoError) \
+                       { \
+                           SkDebugf("Last error string: %s\n", SkGetLastErrorString());\
+                           SkClearLastError(); \
+                       }\
+                       
+void cb(SkError err, void *context) {
+    int *context_ptr = static_cast<int *>(context);
+    SkDebugf("CB (0x%x): %s\n", *context_ptr, SkGetLastErrorString());
+}
+
+static void ErrorTest(skiatest::Reporter* reporter) {
+    SkError err;
+    
+    CHECK(NoError);
+    
+    SkRect r = SkRect::MakeWH(50, 100);
+    CHECK(NoError);
+
+    SkPath path;
+    path.addRect(r);
+    CHECK(NoError);
+    
+    path.addRoundRect(r, 10, 10);
+    CHECK(NoError);
+
+    // should trigger the default error callback, which just prints to the scren.
+    path.addRoundRect(r, -10, -10);
+    CHECK(InvalidArgument);
+    CHECK(NoError);
+
+    int test_value = 0xdeadbeef;
+    SkSetErrorCallback(cb, &test_value);
+
+    // should trigger *our* callback.
+    path.addRoundRect(r, -10, -10);
+    CHECK(InvalidArgument);
+    CHECK(NoError);
+
+    // Should trigger the default one again.
+    SkSetErrorCallback(NULL, NULL);
+    path.addRoundRect(r, -10, -10);
+    CHECK(InvalidArgument);
+    CHECK(NoError);
+}
+
+#include "TestClassDef.h"
+DEFINE_TESTCLASS("Error", ErrorTestClass, ErrorTest)