[Piglit] [PATCH] Test that ES frag shader with invariant outputs compiles

[Danylo Piliaiev]

In all GLSL ES versions output variables in fragment shader are allowed
to be invariant.

 From Section 4.6.1 ("The Invariant Qualifier") GLSL ES 1.00 spec:
 "Only the following variables may be declared as invariant:
   ...
   - Built-in special variables output from the fragment shader."

 From Section 4.6.1 ("The Invariant Qualifier") GLSL ES 3.00 spec:
 "Only variables output from a shader can be candidates for invariance."

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107842

Signed-off-by: Danylo Piliaiev <danylo.piliaiev at globallogic.com>
---
 .../glslparsertest/shaders/invariant.V100.frag | 18 ++++++++++++++++++
 .../glslparsertest/shaders/invariant.V300.frag | 16 ++++++++++++++++
 2 files changed, 34 insertions(+)
 create mode 100644 tests/glslparsertest/shaders/invariant.V100.frag
 create mode 100644 tests/glslparsertest/shaders/invariant.V300.frag

diff --git a/tests/glslparsertest/shaders/invariant.V100.frag b/tests/glslparsertest/shaders/invariant.V100.frag
new file mode 100644
index 000000000..a6463d1dd
--- /dev/null
+++ b/tests/glslparsertest/shaders/invariant.V100.frag
@@ -0,0 +1,18 @@
+// [config]
+// expect_result: pass
+// glsl_version: 1.00
+//
+// [end config]
+
+/* From Section 4.6.1 ("The Invariant Qualifier") GLSL ES 1.00 spec:
+ *
+ *     "Only the following variables may be declared as invariant:
+ *      Built-in special variables output from the fragment shader."
+ */
+
+#version 100
+
+invariant gl_FragColor;
+invariant gl_FragData;
+
+void main() { }
diff --git a/tests/glslparsertest/shaders/invariant.V300.frag b/tests/glslparsertest/shaders/invariant.V300.frag
new file mode 100644
index 000000000..8d7707d8c
--- /dev/null
+++ b/tests/glslparsertest/shaders/invariant.V300.frag
@@ -0,0 +1,16 @@
+// [config]
+// expect_result: pass
+// glsl_version: 3.00
+//
+// [end config]
+
+/* From Section 4.6.1 ("The Invariant Qualifier") GLSL ES 3.00 spec:
+ *
+ *     "Only variables output from a shader can be candidates for invariance."
+ */
+
+#version 300 es
+
+invariant out highp vec4 test;
+
+void main() { }
-- 
2.20.1