allow builtin functions to require parameters to be shader inputs

The new interpolateAt* builtins have strange restrictions on the
<interpolant> parameter.

- It must be a shader input, or an element of a shader input array.
- It must not include a swizzle.

V2: Don't abuse ir_var_mode_shader_in for this; make a new flag.

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
Reviewed-by: Ilia Mirkin <imirkin@alum.mit.edu>

1 files changed, 6 insertions, 0 deletions

diff --git a/src/glsl/ir.h b/src/glsl/ir.h
index d5239d4..fa93efd 100644
--- a/src/glsl/ir.h
+++ b/src/glsl/ir.h
@@ -678,6 +678,12 @@ public:
       unsigned from_named_ifc_block_array:1;
 
       /**
+       * Non-zero if the variable must be a shader input. This is useful for
+       * constraints on function parameters.
+       */
+      unsigned must_be_shader_input:1;
+
+      /**
        * \brief Layout qualifier for gl_FragDepth.
        *
        * This is not equal to \c ir_depth_layout_none if and only if this