HLSL: work around FXC failures when dynamically indexing arrays in structs
FXC fails to compile code that assigns to dynamically-indexed fixed-size
arrays in structs on internal shader variables with:
error X3500: array reference cannot be used as an l-value; not natively
addressable
This CL detects this case, and transforms such assignments into copying
out the array to a local variable, assigning to that local, and then
copying the array back.
Also manually regenerate SKIPs for HLSL/FXC after this change, which
fixes 30 tests. Also exposes some "compilation aborted unexpectedly" now
that "array reference cannot be used as an l-value" has been fixed. For
tests that fail for both DXC and FXC, updating SKIPs to the DXC one to
help distinguish actual FXC bugs from valid errors.
Bug: tint:998
Bug: tint:1206
Change-Id: I09204d8d81ab27d1c257538ad702414ccc386543
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/71620
Reviewed-by: Ben Clayton <bclayton@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Antonio Maiorano <amaiorano@google.com>
diff --git a/src/transform/localize_struct_array_assignment.h b/src/transform/localize_struct_array_assignment.h
new file mode 100644
index 0000000..ce56e14
--- /dev/null
+++ b/src/transform/localize_struct_array_assignment.h
@@ -0,0 +1,53 @@
+// Copyright 2021 The Tint Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef SRC_TRANSFORM_LOCALIZE_STRUCT_ARRAY_ASSIGNMENT_H_
+#define SRC_TRANSFORM_LOCALIZE_STRUCT_ARRAY_ASSIGNMENT_H_
+
+#include "src/transform/transform.h"
+
+namespace tint {
+namespace transform {
+
+/// This transforms replaces assignment to dynamically-indexed fixed-size arrays
+/// in structs on shader-local variables with code that copies the arrays to a
+/// temporary local variable, assigns to the local variable, and copies the
+/// array back. This is to work around FXC's compilation failure for these cases
+/// (see crbug.com/tint/1206).
+class LocalizeStructArrayAssignment
+ : public Castable<LocalizeStructArrayAssignment, Transform> {
+ public:
+ /// Constructor
+ LocalizeStructArrayAssignment();
+
+ /// Destructor
+ ~LocalizeStructArrayAssignment() override;
+
+ protected:
+ /// Runs the transform using the CloneContext built for transforming a
+ /// program. Run() is responsible for calling Clone() on the CloneContext.
+ /// @param ctx the CloneContext primed with the input program and
+ /// ProgramBuilder
+ /// @param inputs optional extra transform-specific input data
+ /// @param outputs optional extra transform-specific output data
+ void Run(CloneContext& ctx, const DataMap& inputs, DataMap& outputs) override;
+
+ private:
+ class State;
+};
+
+} // namespace transform
+} // namespace tint
+
+#endif // SRC_TRANSFORM_LOCALIZE_STRUCT_ARRAY_ASSIGNMENT_H_
