commit f0b4dbb82dcde3e9ea152a459a5865bc3d93b3dc
author Ben Clayton <bclayton@google.com> Tue Feb 21 21:05:28 2023 +0000
committer Ben Clayton <bclayton@chromium.org> Tue Feb 21 21:05:28 2023 +0000
tree 2977cb1006177cabf96844ffe2a7f73e25b2a2ac
parent 650426b18793286cc2d11555d5ca0c32cd4e1106

tint: Resolve @interpolate() args as expressions

This CL makes the builtin argument resolve as a shadowable enumerator
expression.

Bug: tint:1841
Bug: tint:1845
Change-Id: I5000ea91771fabb460c80c164bc7708fbbb0288c
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/120722
Reviewed-by: Dan Sinclair <dsinclair@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>

src/tint/writer/hlsl/generator_impl.cc

diff --git a/src/tint/writer/hlsl/generator_impl.cc b/src/tint/writer/hlsl/generator_impl.cc
index 4c7c9ee..dbcd4b6 100644
--- a/src/tint/writer/hlsl/generator_impl.cc
+++ b/src/tint/writer/hlsl/generator_impl.cc
@@ -4219,8 +4219,21 @@
                         }
                         post += " : " + name;
                     } else if (auto* interpolate = attr->As<ast::InterpolateAttribute>()) {
-                        auto mod =
-                            interpolation_to_modifiers(interpolate->type, interpolate->sampling);
+                        auto& sem = program_->Sem();
+                        auto i_type =
+                            sem.Get<sem::BuiltinEnumExpression<builtin::InterpolationType>>(
+                                   interpolate->type)
+                                ->Value();
+
+                        auto i_smpl = builtin::InterpolationSampling::kUndefined;
+                        if (interpolate->sampling) {
+                            i_smpl =
+                                sem.Get<sem::BuiltinEnumExpression<builtin::InterpolationSampling>>(
+                                       interpolate->sampling)
+                                    ->Value();
+                        }
+
+                        auto mod = interpolation_to_modifiers(i_type, i_smpl);
                         if (mod.empty()) {
                             diagnostics_.add_error(diag::System::Writer,
                                                    "unsupported interpolation");