commit 79f7104ab9aa7777c0531bc6333160e7f45d9e50
author Geoff Lang <geofflang@chromium.org> Mon Aug 14 16:43:43 2017 -0400
committer Commit Bot <commit-bot@chromium.org> Tue Aug 15 14:28:28 2017 +0000
tree 3351f50fd9e43dcac87dec60dae5818ea964c1d5
parent 78ed6cd9ea00fa2b905e849f6a54ad91ee68f3b3

Validate that transform feedback buffers are not mapped.

Mapping a buffer that is bound for active transform feedback or starting
transform feedback on a mapped buffer is undefined behaviour under
section 2.10.3.2 of the ES 3.0 spec "Effects of Mapping Buffers on Other
GL Commands".  The spec suggests that an error is generated in this
case.

TEST=ES3MapBufferRangeTest.TransformFeedback

BUG=754000

Change-Id: I613defd07cc1a4348682d992cda61cc898936720
Reviewed-on: https://chromium-review.googlesource.com/614483
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Geoff Lang <geofflang@chromium.org>

src/libANGLE/validationES2.cpp

diff --git a/src/libANGLE/validationES2.cpp b/src/libANGLE/validationES2.cpp
index 2810c11..3ad049c 100644
--- a/src/libANGLE/validationES2.cpp
+++ b/src/libANGLE/validationES2.cpp
@@ -2777,7 +2777,7 @@
         return false;
     }
 
-    return true;
+    return ValidateMapBufferBase(context, target);
 }
 
 bool ValidateUnmapBufferOES(Context *context, GLenum target)
@@ -2806,6 +2806,30 @@
     return ValidateMapBufferRangeBase(context, target, offset, length, access);
 }
 
+bool ValidateMapBufferBase(Context *context, GLenum target)
+{
+    Buffer *buffer = context->getGLState().getTargetBuffer(target);
+    ASSERT(buffer != nullptr);
+
+    // Check if this buffer is currently being used as a transform feedback output buffer
+    TransformFeedback *transformFeedback = context->getGLState().getCurrentTransformFeedback();
+    if (transformFeedback != nullptr && transformFeedback->isActive())
+    {
+        for (size_t i = 0; i < transformFeedback->getIndexedBufferCount(); i++)
+        {
+            const auto &transformFeedbackBuffer = transformFeedback->getIndexedBuffer(i);
+            if (transformFeedbackBuffer.get() == buffer)
+            {
+                context->handleError(InvalidOperation()
+                                     << "Buffer is currently bound for transform feedback.");
+                return false;
+            }
+        }
+    }
+
+    return true;
+}
+
 bool ValidateFlushMappedBufferRangeEXT(Context *context,
                                        GLenum target,
                                        GLintptr offset,