From 174048f26c147e31a6f72907a3af5dfafeedb877 Mon Sep 17 00:00:00 2001
From: Yong He <yonghe@outlook.com>
Date: Thu, 1 Sep 2022 11:14:59 -0700
Subject: Small fix to enable generic typealias. (#2391)

* Small fix to enable generic typealias.

* Fix.

Co-authored-by: Yong He <yhe@nvidia.com>
---
 source/slang/slang-lower-to-ir.cpp                  |  4 ++++
 tests/language-feature/generics/typealias.slang     | 21 +++++++++++++++++++++
 .../generics/typealias.slang.expected.txt           |  5 +++++
 3 files changed, 30 insertions(+)
 create mode 100644 tests/language-feature/generics/typealias.slang
 create mode 100644 tests/language-feature/generics/typealias.slang.expected.txt

diff --git a/source/slang/slang-lower-to-ir.cpp b/source/slang/slang-lower-to-ir.cpp
index d9080169a..31472e878 100644
--- a/source/slang/slang-lower-to-ir.cpp
+++ b/source/slang/slang-lower-to-ir.cpp
@@ -8119,6 +8119,10 @@ struct DeclLoweringVisitor : DeclVisitor<DeclLoweringVisitor, LoweredValInfo>
         {
             return ensureDecl(context, interfaceDecl);
         }
+        else if (auto typedefDecl = as<TypeDefDecl>(genDecl->inner))
+        {
+            return ensureDecl(context, typedefDecl);
+        }
         SLANG_RELEASE_ASSERT(false);
         UNREACHABLE_RETURN(LoweredValInfo());
     }
diff --git a/tests/language-feature/generics/typealias.slang b/tests/language-feature/generics/typealias.slang
new file mode 100644
index 000000000..3895c984a
--- /dev/null
+++ b/tests/language-feature/generics/typealias.slang
@@ -0,0 +1,21 @@
+//TEST(compute):COMPARE_COMPUTE: -shaderobj -output-using-type
+//TEST(compute):COMPARE_COMPUTE: -vk -shaderobj -output-using-type
+struct MyGenType<T : IArithmetic, let n : int>
+{
+    T value;
+    T compute() { return value * T(n); }
+}
+
+typealias IntMyGenType<let n : int> = MyGenType<int, n>;
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):out,name=outputBuffer
+RWStructuredBuffer<int> outputBuffer;
+
+[numthreads(4, 1, 1)]
+void computeMain(int3 dispatchThreadID : SV_DispatchThreadID)
+{
+    int tid = dispatchThreadID.x;
+    IntMyGenType<2> obj;
+    obj.value = 2;
+    outputBuffer[tid] = obj.compute();
+}
diff --git a/tests/language-feature/generics/typealias.slang.expected.txt b/tests/language-feature/generics/typealias.slang.expected.txt
new file mode 100644
index 000000000..acea53ef2
--- /dev/null
+++ b/tests/language-feature/generics/typealias.slang.expected.txt
@@ -0,0 +1,5 @@
+type: int32_t
+4
+4
+4
+4
-- 
cgit v1.2.3