[Piglit] [PATCH] es3: add tests for verifying overloading behavior

[Ilia Mirkin]

An existing bug in mesa made it so that overloads of any functions that
might be builtins in any language version or extension would not be
overridable in ESSL 3.00 shaders. This adds tests to ensure that
builtins available in ESSL 3.00 are rejected properly, but builtins from
future versions or non-enabled (or available) extensions are allowed to
be specified.

Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
---
 tests/spec/glsl-es-3.00/compiler/overload-builtin.frag    | 14 ++++++++++++++
 .../glsl-es-3.00/compiler/overload-future-builtin.frag    | 15 +++++++++++++++
 2 files changed, 29 insertions(+)
 create mode 100644 tests/spec/glsl-es-3.00/compiler/overload-builtin.frag
 create mode 100644 tests/spec/glsl-es-3.00/compiler/overload-future-builtin.frag

diff --git a/tests/spec/glsl-es-3.00/compiler/overload-builtin.frag b/tests/spec/glsl-es-3.00/compiler/overload-builtin.frag
new file mode 100644
index 000000000..8ed837655
--- /dev/null
+++ b/tests/spec/glsl-es-3.00/compiler/overload-builtin.frag
@@ -0,0 +1,14 @@
+// [config]
+// expect_result: fail
+// glsl_version: 3.00
+// [end config]
+//
+// Check that builtins may not be overloaded, even with different parameters.
+//
+// From GLSL ES 3.0 spec, chapter 6.1 "Function Definitions", page 71:
+//
+//     "A shader cannot redefine or overload built-in functions."
+//
+#version 300 es
+
+int sqrt(int x) { return x; }
diff --git a/tests/spec/glsl-es-3.00/compiler/overload-future-builtin.frag b/tests/spec/glsl-es-3.00/compiler/overload-future-builtin.frag
new file mode 100644
index 000000000..a3b3ae1cf
--- /dev/null
+++ b/tests/spec/glsl-es-3.00/compiler/overload-future-builtin.frag
@@ -0,0 +1,15 @@
+// [config]
+// expect_result: pass
+// glsl_version: 3.00
+// [end config]
+//
+// Check that builtins that are not available in ESSL 3.00 may be defined
+// or overloaded as needed.
+//
+#version 300 es
+precision highp float;
+
+int bitfieldExtract(int x) { return x; }
+int imageAtomicAdd(int x) { return x; }
+void barrier() { }
+uint packUnorm4x8(vec4 v) { return uint(v.x); }
-- 
2.13.0