[Piglit] [PATCH 5/7] arb_enhanced_layouts: test component qualifier for overlaps

[Timothy Arceri]

From: Timothy Arceri <timothy.arceri at collabora.com>

---
 .../compiler/component-layout/overlap-double.vert  | 31 ++++++++++++++
 .../compiler/component-layout/overlap-illegal.vert | 32 +++++++++++++++
 .../compiler/component-layout/overlap-legal.vert   | 47 ++++++++++++++++++++++
 3 files changed, 110 insertions(+)
 create mode 100644 tests/spec/arb_enhanced_layouts/compiler/component-layout/overlap-double.vert
 create mode 100644 tests/spec/arb_enhanced_layouts/compiler/component-layout/overlap-illegal.vert
 create mode 100644 tests/spec/arb_enhanced_layouts/compiler/component-layout/overlap-legal.vert

diff --git a/tests/spec/arb_enhanced_layouts/compiler/component-layout/overlap-double.vert b/tests/spec/arb_enhanced_layouts/compiler/component-layout/overlap-double.vert
new file mode 100644
index 0000000..255ecdf
--- /dev/null
+++ b/tests/spec/arb_enhanced_layouts/compiler/component-layout/overlap-double.vert
@@ -0,0 +1,31 @@
+// [config]
+// expect_result: fail
+// glsl_version: 1.40
+// check_link: true
+// require_extensions: GL_ARB_enhanced_layouts GL_ARB_gpu_shader_fp64 GL_ARB_separate_shader_objects
+// [end config]
+//
+// From Section 4.4.1 (Input Layout Qualifiers) of the GLSL 4.50 spec:
+//
+//   "Location aliasing is causing two variables or block members to have the
+//   same location number. Component aliasing is assigning the same (or
+//   overlapping) component numbers for two location aliases. (Recall if
+//   component is not used, components are assigned starting with 0.) With one
+//   exception, location aliasing is allowed only if it does not cause
+//   component aliasing; it is a compile-time or link-time error to cause
+//   component aliasing."
+
+#version 140
+#extension GL_ARB_enhanced_layouts: require
+#extension GL_ARB_gpu_shader_fp64: require
+#extension GL_ARB_separate_shader_objects: require
+
+// consume X/Y components
+layout(location = 7, component = 0) out double a;
+
+// consumes Y component
+layout(location = 7, component = 1) out float b;
+
+void main()
+{
+}
diff --git a/tests/spec/arb_enhanced_layouts/compiler/component-layout/overlap-illegal.vert b/tests/spec/arb_enhanced_layouts/compiler/component-layout/overlap-illegal.vert
new file mode 100644
index 0000000..d7d15e6
--- /dev/null
+++ b/tests/spec/arb_enhanced_layouts/compiler/component-layout/overlap-illegal.vert
@@ -0,0 +1,32 @@
+// [config]
+// expect_result: fail
+// glsl_version: 1.40
+// check_link: true
+// require_extensions: GL_ARB_enhanced_layouts GL_ARB_separate_shader_objects
+// [end config]
+//
+// From Section 4.4.1 (Input Layout Qualifiers) of the GLSL 4.50 spec:
+//
+//   "Location aliasing is causing two variables or block members to have the
+//   same location number. Component aliasing is assigning the same (or
+//   overlapping) component numbers for two location aliases. (Recall if
+//   component is not used, components are assigned starting with 0.) With one
+//   exception, location aliasing is allowed only if it does not cause
+//   component aliasing; it is a compile-time or link-time error to cause
+//   component aliasing."
+
+#version 140
+#extension GL_ARB_enhanced_layouts: require
+#extension GL_ARB_separate_shader_objects: require
+
+// consume Y/Z/W components
+layout(location = 0, component = 1) out vec3 a;
+
+// consumes W component
+layout(location = 0, component = 3) out float b;
+
+void main()
+{
+  a = vec3(1.0);
+  b = 0.0;
+}
diff --git a/tests/spec/arb_enhanced_layouts/compiler/component-layout/overlap-legal.vert b/tests/spec/arb_enhanced_layouts/compiler/component-layout/overlap-legal.vert
new file mode 100644
index 0000000..adcbe19
--- /dev/null
+++ b/tests/spec/arb_enhanced_layouts/compiler/component-layout/overlap-legal.vert
@@ -0,0 +1,47 @@
+// [config]
+// expect_result: pass
+// glsl_version: 1.40
+// check_link: true
+// require_extensions: GL_ARB_enhanced_layouts GL_ARB_explicit_attrib_location
+// [end config]
+//
+// From Section 4.4.1 (Input Layout Qualifiers) of the GLSL 4.50 spec:
+//
+//   "Location aliasing is causing two variables or block members to have the
+//   same location number. Component aliasing is assigning the same (or
+//   overlapping) component numbers for two location aliases. (Recall if
+//   component is not used, components are assigned starting with 0.) With one
+//   exception, location aliasing is allowed only if it does not cause
+//   component aliasing; it is a compile-time or link-time error to cause
+//   component aliasing."
+//
+//   ...
+//
+//   "The one exception where component aliasing is permitted is for two input
+//   variables (not block members) to a vertex shader, which are allowed to
+//   have component aliasing. This vertex-variable component aliasing is
+//   intended only to support vertex shaders where each execution path
+//   accesses at most one input per each aliased component.  Implementations
+//   are permitted, but not required, to generate link-time errors if they
+//   detect that every path through the vertex shader executable accesses
+//   multiple inputs aliased to any single component."
+
+#version 140
+#extension GL_ARB_enhanced_layouts: require
+#extension GL_ARB_explicit_attrib_location: require
+
+uniform int i;
+
+// consume Y/Z/W components
+layout(location = 0, component = 1) in vec3 a;
+
+// consumes W component
+layout(location = 0, component = 3) in float b;
+
+void main()
+{
+  if (i == 1)
+    gl_Position = vec4(b);
+  else
+    gl_Position = vec4(a, 1.0);
+}
-- 
2.4.3