Proper lowering of functiosn that returns NonCopyable values. (#3179)

* Proper lowering of functiosn that returns NonCopyable values.

* Fix tests.

* Fix clang errors.

* Fix.

* Fix clang error.

---------

Co-authored-by: Yong He <yhe@nvidia.com>

1 files changed, 37 insertions, 0 deletions

diff --git a/tests/language-feature/non-copyable-return.slang b/tests/language-feature/non-copyable-return.slang
new file mode 100644
index 000000000..20330c5f9
--- /dev/null
+++ b/tests/language-feature/non-copyable-return.slang
@@ -0,0 +1,37 @@
+//TEST(compute):COMPARE_COMPUTE(filecheck-buffer=CHECK): -shaderobj -output-using-type
+//TEST(compute):SIMPLE(filecheck=GLSL): -stage compute -entry computeMain -target glsl
+
+// Note: spirv_by_reference is only supported for passing opaque types, so this test won't produce
+// expected result on vulkan.
+//DISABLED_TEST(compute):COMPARE_COMPUTE(filecheck-buffer=CHECK): -vk -shaderobj -output-using-type
+
+[__NonCopyableType]
+struct MyType
+{
+    float x;
+    __init() { x = 1.0; }
+}
+
+MyType myFunc1(float y)
+{
+    __return_val = MyType();
+    __return_val.x += y;
+}
+
+MyType myFunc0(float x)
+{
+    return myFunc1(x + 1.0);
+}
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):out,name=outputBuffer
+RWStructuredBuffer<float> outputBuffer;
+
+[numthreads(1, 1, 1)]
+void computeMain(int3 dispatchThreadID: SV_DispatchThreadID)
+{
+    let f = myFunc0(2.0);
+    // CHECK: 4.0
+    // GLSL: void myFunc1_0(float y{{.*}}, spirv_by_reference MyType_0 {{.*}})
+    // GLSL: void myFunc0_0(float x{{.*}}, spirv_by_reference MyType_0 {{.*}})
+    outputBuffer[0] = f.x;
+}