Fix `ApplyExtensionToType` on own type being extended. (#2430)

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

2 files changed, 32 insertions, 0 deletions

diff --git a/tests/bugs/generic-extension.slang b/tests/bugs/generic-extension.slang
new file mode 100644
index 000000000..a3e039872
--- /dev/null
+++ b/tests/bugs/generic-extension.slang
@@ -0,0 +1,28 @@
+//TEST(compute):COMPARE_COMPUTE_EX:-slang -compute -shaderobj
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):out,name outputBuffer
+RWStructuredBuffer<int> outputBuffer;
+
+interface IFoo
+{
+  static This myAdd(This v, float val);   
+}
+
+__generic<let N : int>
+extension vector<float, N> : IFoo
+{
+  static vector<float, N> myAdd(vector<float, N> v, float val)
+  {
+    return v + vector<float, N>(val);
+  }
+}
+
+[numthreads(4, 1, 1)]
+void computeMain(uint3 dispatchThreadID: SV_DispatchThreadID)
+{
+  int index = int(dispatchThreadID.x);
+  float2 v = 1.0;
+  v = float2.myAdd(v, 2.0);
+  outputBuffer[index] = int(v.x);
+}
+
diff --git a/tests/bugs/generic-extension.slang.expected.txt b/tests/bugs/generic-extension.slang.expected.txt
new file mode 100644
index 000000000..463fa2702
--- /dev/null
+++ b/tests/bugs/generic-extension.slang.expected.txt
@@ -0,0 +1,4 @@
+3
+3
+3
+3