Drain sink when single-argument constructor call fail (#7883)

* fix bug

* fix test

* push test changs for clarity

* fix bug

* fix test

* push test changs for clarity

* test what fails

* remove redundant code

1 files changed, 52 insertions, 0 deletions

diff --git a/tests/bugs/gh-7856.slang b/tests/bugs/gh-7856.slang
new file mode 100644
index 000000000..b1edec8b5
--- /dev/null
+++ b/tests/bugs/gh-7856.slang
@@ -0,0 +1,52 @@
+//DIAGNOSTIC_TEST:SIMPLE(filecheck=CHECK): -target spirv -entry computeMain -stage compute
+
+enum A
+{
+    V1,
+    V2,
+    V3
+}
+
+enum B
+{
+    V1,
+    V2,
+    V3
+}
+
+struct Foo<T, A access = A::V1, B addrSpace = B::V1>
+{
+    int a;
+    __init(int b) { a = b; }
+    __init<U, A accessOther>(Foo<U, accessOther, addrSpace> ptr)
+    {
+    }
+
+    // internally Slang is throwing an error, we just don't drain the error
+    // from our sink
+    __init(uint64_t val) {}
+    __init(int64_t val) {}
+}
+
+extension int64_t
+{
+    __init<T, A access, B addrSpace>(Foo<T, access, addrSpace> t) {}
+}
+extension uint64_t
+{
+    __init<T, A access, B addrSpace>(Foo<T, access, addrSpace> t) {}
+}
+
+RWStructuredBuffer<int> output;
+
+[shader("compute")]
+[numthreads(1, 1, 1)]
+void computeMain(uint3 threadId: SV_DispatchThreadID)
+{
+    Foo<int, A.V1, B.V1> v1 = Foo<int, A.V1, B.V1>(1);
+
+    // CHECK: ([[# @LINE+1]]): error 30080
+    Foo<float, A.V1, B.V2> v2 = Foo<float, A.V1, B.V2>(v1);
+
+    output[0] = v1.a;
+}