transform/shader_io: Generate a wrapper function
This is a major reworking of this transform. The old transform code
was getting unwieldy, with part of the complication coming from the
handling of multiple return statements. By generating a wrapper
function instead, we can avoid a lot of this complexity.
The original entry point function is stripped of all shader IO
attributes (as well as `stage` and `workgroup_size`), but the body is
left unmodified. A new entry point wrapper function is introduced
which calls the original function, packing/unpacking the shader inputs
as necessary, and propagates the result to the corresponding shader
outputs.
The new code has been refactored to use a state object with the
different parts of the transform split into separate functions, which
makes it much more manageable.
Fixed: tint:1076
Bug: tint:920
Change-Id: I3490a0ea7a3509a4e198ce730e476516649d8d96
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/60521
Auto-Submit: James Price <jrprice@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: James Price <jrprice@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
diff --git a/test/shader_io/shared_struct_helper_function.wgsl.expected.hlsl b/test/shader_io/shared_struct_helper_function.wgsl.expected.hlsl
index 8e85183..8ee4d8e 100644
--- a/test/shader_io/shared_struct_helper_function.wgsl.expected.hlsl
+++ b/test/shader_io/shared_struct_helper_function.wgsl.expected.hlsl
@@ -4,8 +4,8 @@
};
VertexOutput foo(float x) {
- const VertexOutput tint_symbol_4 = {float4(x, x, x, 1.0f), 42};
- return tint_symbol_4;
+ const VertexOutput tint_symbol_2 = {float4(x, x, x, 1.0f), 42};
+ return tint_symbol_2;
}
struct tint_symbol {
@@ -13,19 +13,31 @@
float4 pos : SV_Position;
};
-tint_symbol vert_main1() {
- const VertexOutput tint_symbol_1 = foo(0.5f);
- const tint_symbol tint_symbol_5 = {tint_symbol_1.loc0, tint_symbol_1.pos};
- return tint_symbol_5;
+VertexOutput vert_main1_inner() {
+ return foo(0.5f);
}
-struct tint_symbol_2 {
+tint_symbol vert_main1() {
+ const VertexOutput inner_result = vert_main1_inner();
+ tint_symbol wrapper_result = (tint_symbol)0;
+ wrapper_result.pos = inner_result.pos;
+ wrapper_result.loc0 = inner_result.loc0;
+ return wrapper_result;
+}
+
+struct tint_symbol_1 {
int loc0 : TEXCOORD0;
float4 pos : SV_Position;
};
-tint_symbol_2 vert_main2() {
- const VertexOutput tint_symbol_3 = foo(0.25f);
- const tint_symbol_2 tint_symbol_6 = {tint_symbol_3.loc0, tint_symbol_3.pos};
- return tint_symbol_6;
+VertexOutput vert_main2_inner() {
+ return foo(0.25f);
+}
+
+tint_symbol_1 vert_main2() {
+ const VertexOutput inner_result_1 = vert_main2_inner();
+ tint_symbol_1 wrapper_result_1 = (tint_symbol_1)0;
+ wrapper_result_1.pos = inner_result_1.pos;
+ wrapper_result_1.loc0 = inner_result_1.loc0;
+ return wrapper_result_1;
}
