Add diagnostic to prevent defining unsized variables. (#4168)

* Add diagnostic to prevent defining unsized static variables.

* Fix tests.

* Add more tests.

* Fix to allow defining variables of link-time size.

* update diagnostic message.

* Fix tests.

* Simplify code.

2 files changed, 50 insertions, 0 deletions

diff --git a/tests/bugs/gh-4150.slang b/tests/bugs/gh-4150.slang
new file mode 100644
index 000000000..031d778a9
--- /dev/null
+++ b/tests/bugs/gh-4150.slang
@@ -0,0 +1,49 @@
+//TEST:SIMPLE(filecheck=CHECK1):-target spirv -DERROR1
+//TEST:SIMPLE(filecheck=CHECK2):-target spirv -DERROR2
+extern static const int constValue = 1;
+
+struct RWTex<T : __BuiltinRealType, let N : uint>
+{
+#ifdef ERROR2
+    // expect error: cannot define static member with unsized type.
+    // CHECK2:([[# @LINE+1]]): error 30071
+    static [[vk::binding(0, 0)]] vector<T,N> rwtable[];
+#else
+    static [[vk::binding(0, 0)]] vector<T,N> rwtable[4];
+#endif
+    static vector<T, N> get(uint image_index) { return rwtable[image_index]; }
+}    
+
+struct Push
+{
+    uint image_id;
+};
+[[vk::push_constant]] Push p;
+RWStructuredBuffer<float3> output;
+[shader("compute")]
+[numthreads(8, 8, 1)]
+void main(uint3 pixel_i : SV_DispatchThreadID)
+{
+    output[0] =
+#ifdef ERROR1
+        // expect error: trying to specialize RWTex, which has two arguments, with only one argument.
+        // CHECK1:([[# @LINE+1]]): error 30075
+        RWTex<float3>::get(p.image_id);
+#else
+        RWTex<float, 3>::get(p.image_id);
+#endif
+    //CHECK1:([[# @LINE+1]]): error 30071
+    static float sa1[];
+
+    //CHECK1:([[# @LINE+1]]): error 30071
+    float sa2[];
+
+    //CHECK1-NOT:([[# @LINE+1]]): error
+    static float sa3[] = { 1, 2, 3 }; // should be ok.
+
+    //CHECK1-NOT:([[# @LINE+1]]): error
+    float sa4[] = { 1, 2, 3 }; // should be ok.
+
+    //CHECK1-NOT:([[# @LINE+1]]): error
+    float sa5[constValue]; // should be ok.
+}
diff --git a/tests/diagnostics/unsized.slang b/tests/diagnostics/unsized.slang
index 6bcad95a9..6b14353b5 100644
--- a/tests/diagnostics/unsized.slang
+++ b/tests/diagnostics/unsized.slang
@@ -5,6 +5,7 @@ extern static const int size = 1;
 struct V
 {
     // CHECK-DAG: ([[# @LINE+1]]): error 30070
+    int c[];
     int b[size];
     int a[];
 }