[Piglit] [PATCH v2 10/10] arb_enhanced_layouts: add xfb_offset overlap test

[Andres Gomez]

>From the GL_ARB_enhanced_layouts spec:

  " No aliasing in output buffers is allowed: It is a compile-time or
    link-time error to specify variables with overlapping transform
    feedback offsets."

v2: added forgotten check_link.

Cc: Timothy Arceri <tarceri at itsqueeze.com>
Signed-off-by: Andres Gomez <agomez at igalia.com>
---
 .../xfb_offset/invalid-overlap.vert           | 24 +++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 tests/spec/arb_enhanced_layouts/compiler/transform-feedback-layout-qualifiers/xfb_offset/invalid-overlap.vert

diff --git a/tests/spec/arb_enhanced_layouts/compiler/transform-feedback-layout-qualifiers/xfb_offset/invalid-overlap.vert b/tests/spec/arb_enhanced_layouts/compiler/transform-feedback-layout-qualifiers/xfb_offset/invalid-overlap.vert
new file mode 100644
index 000000000..5e8adc154
--- /dev/null
+++ b/tests/spec/arb_enhanced_layouts/compiler/transform-feedback-layout-qualifiers/xfb_offset/invalid-overlap.vert
@@ -0,0 +1,24 @@
+// [config]
+// expect_result: fail
+// glsl_version: 1.40
+// check_link: true
+// require_extensions: GL_ARB_enhanced_layouts
+// [end config]
+//
+// From the GL_ARB_enhanced_layouts spec:
+//
+//   " No aliasing in output buffers is allowed: It is a compile-time
+//     or link-time error to specify variables with overlapping
+//     transform feedback offsets."
+
+#version 140
+#extension GL_ARB_enhanced_layouts: require
+
+layout(xfb_offset = 0) out vec4 a;
+layout(xfb_offset = 0) out vec4 b;
+
+void main()
+{
+  a = vec4(1.0);
+  b = vec4(0.0);
+}
-- 
2.20.1