Warnings function parameters (#4626)

* Handle out/inout functions with separate consideration

* Fixing bug with passing aliasable instructions

* Handle autodiff functions (fwd and rev) in warning system

* Handling interface methods

* Handling ref parameters like out/inout

* Temporary fix to remaining bugs

* Refactoring methods and tests

* Recursive check for empty structs

* Using default initializable interface in tests

* Resolving CI fail

18 files changed, 240 insertions, 154 deletions

diff --git a/tests/autodiff/material2/MxWeights.slang b/tests/autodiff/material2/MxWeights.slang
index 1e9c7d36c..244d97c73 100644
--- a/tests/autodiff/material2/MxWeights.slang
+++ b/tests/autodiff/material2/MxWeights.slang
@@ -3,6 +3,12 @@
 public struct MxWeights<let TBsdfCount : int>
 {
     public float3 weights[TBsdfCount];
+
+    public __init()
+    {
+        for (int i = 0; i < TBsdfCount; i++)
+            weights[i] = float3(0.0f);
+    }
 }
 
 public interface IMxLayeredMaterialData
diff --git a/tests/bugs/generic-param-cast.slang b/tests/bugs/generic-param-cast.slang
index 20b30a433..e2dbcc285 100644
--- a/tests/bugs/generic-param-cast.slang
+++ b/tests/bugs/generic-param-cast.slang
@@ -8,7 +8,7 @@ struct A<let I : int>
     int f() { return I; }
 };
 
-struct B<let U : uint>
+struct B<let U : uint> : IDefaultInitializable
 {
     A<U> a;
 };
diff --git a/tests/bugs/specialize-existential-in-generic.slang b/tests/bugs/specialize-existential-in-generic.slang
index 695c7bc29..cb05aea14 100644
--- a/tests/bugs/specialize-existential-in-generic.slang
+++ b/tests/bugs/specialize-existential-in-generic.slang
@@ -18,7 +18,7 @@ struct Impl : IFoo
     Assoc getValue() { Assoc r; return r; }
 }
 
-struct GenType<T : IFoo>
+struct GenType<T : IFoo> : IDefaultInitializable
 {
     T obj;
     int doThing()
diff --git a/tests/compute/assoctype-func-param.slang b/tests/compute/assoctype-func-param.slang
index 830cc00cc..6d6bf5b6d 100644
--- a/tests/compute/assoctype-func-param.slang
+++ b/tests/compute/assoctype-func-param.slang
@@ -37,7 +37,7 @@ struct GenStruct<T> : IBase
 
 U.RetT test<U:IBase>(U.RetT val)
 {
-    U obj;
+    U obj = U();
     U.SubTypeT sb = obj.setVal(val);
     return obj.getVal(sb);
 }
@@ -50,4 +50,4 @@ void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
     /* wrong error message for the following line */
     float outVal = test<GenStruct<float> >(inVal);
     outputBuffer[tid] = outVal.x;
-}
\ No newline at end of file
+}
diff --git a/tests/compute/assoctype-nested-lookup.slang b/tests/compute/assoctype-nested-lookup.slang
index b1ca75d49..64a5d29a5 100644
--- a/tests/compute/assoctype-nested-lookup.slang
+++ b/tests/compute/assoctype-nested-lookup.slang
@@ -12,7 +12,7 @@ interface IFoo : IDefaultInitializable
 };
 
 
-struct FooPair<T : IFoo> : IFoo
+struct FooPair<T : IFoo> : IFoo, IDefaultInitializable
 {
     T a;
     T.Bar b;
@@ -41,4 +41,4 @@ void computeMain(uint3 dispatchThreadID: SV_DispatchThreadID)
 {
     FooPair<ConcreteFoo>.Bar pair;
     test(pair);
-}
\ No newline at end of file
+}
diff --git a/tests/compute/dynamic-dispatch-17.slang b/tests/compute/dynamic-dispatch-17.slang
index bc2b9a6d9..e89482a5b 100644
--- a/tests/compute/dynamic-dispatch-17.slang
+++ b/tests/compute/dynamic-dispatch-17.slang
@@ -52,7 +52,7 @@ struct FloatVal : IInterface
     float val;
     float run<Z:IReturnsZero>()
     {
-        Z z;
+        Z z = Z();
         return val + z.get();
     }
 };
@@ -62,7 +62,7 @@ struct Float4Val : IInterface
     Float4Struct val;
     float run<Z:IReturnsZero>()
     {
-        Z z;
+        Z z = Z();
         return val.val.x + val.val.y + z.get();
     }
 };
diff --git a/tests/compute/empty-struct2.slang b/tests/compute/empty-struct2.slang
index 27e587b42..303cfd234 100644
--- a/tests/compute/empty-struct2.slang
+++ b/tests/compute/empty-struct2.slang
@@ -25,8 +25,8 @@ struct EmptyS : IEmptyS
 struct Empty<TT : IEmptyS> : IInterface
 {
     typedef TT T;
-    TT value;
-    float a;
+    TT value = TT();
+    float a = 0;
     TT getT()
     {
         return value;
@@ -51,4 +51,4 @@ void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
     Empty<EmptyS> obj;
     test(obj);
     outputBuffer[dispatchThreadID.x] = dispatchThreadID.x;
-}
\ No newline at end of file
+}
diff --git a/tests/compute/generic-closer.slang b/tests/compute/generic-closer.slang
index 377b42dab..c497b14d0 100644
--- a/tests/compute/generic-closer.slang
+++ b/tests/compute/generic-closer.slang
@@ -13,7 +13,7 @@ struct Gen0 : IGetter
 };
 struct Gen1<TGetter : IGetter> : IGetter
 {
-    TGetter g;
+    TGetter g = TGetter();
     int get() { return g.get(); }
 };
 
@@ -39,4 +39,4 @@ void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
     int b = 5;
     if (a< b && b > a)
 	    outputBuffer[dispatchThreadID.x] = (g.get() >> 1) + g2.get() + g3.get();
-}
\ No newline at end of file
+}
diff --git a/tests/compute/generic-default-arg.slang b/tests/compute/generic-default-arg.slang
index 8762f5e8a..3a3a4a5b8 100644
--- a/tests/compute/generic-default-arg.slang
+++ b/tests/compute/generic-default-arg.slang
@@ -31,7 +31,7 @@ struct Impl2 : ITest
 __generic<T : ITest = Impl1>
 struct GenStruct
 {
-	T obj;
+	T obj = T();
 };
 
 int test(GenStruct gs, int val)
@@ -50,4 +50,4 @@ void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
 	outVal += test(gs, tid);
 
 	outputBuffer[tid] = outVal;
-}
\ No newline at end of file
+}
diff --git a/tests/compute/transitive-interface.slang b/tests/compute/transitive-interface.slang
index e4d7db91d..d8b167bd7 100644
--- a/tests/compute/transitive-interface.slang
+++ b/tests/compute/transitive-interface.slang
@@ -47,7 +47,7 @@ struct AssocImpl : IAssoc
 
 int testAdd2<T:IAssoc>(T assoc)
 {
-    T.AT obj;
+    T.AT obj = T.AT();
     return obj.addf(1, 1);
 }
 
@@ -69,4 +69,4 @@ void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
     outVal += testSub(s1, outVal);
 
 	outputBuffer[dispatchThreadID.x] = outVal;
-}
\ No newline at end of file
+}
diff --git a/tests/cuda/cuda-array-layout.slang b/tests/cuda/cuda-array-layout.slang
index 60f318962..b99ab84c8 100644
--- a/tests/cuda/cuda-array-layout.slang
+++ b/tests/cuda/cuda-array-layout.slang
@@ -10,7 +10,7 @@ struct PadLadenStruct
 };
 
 // This is to check if the last half can be inserted 'inside' the spare padding of a. It should not be
-struct StructWithArray
+struct StructWithArray : IDefaultInitializable
 {
     PadLadenStruct a[1];
     uint8_t b;
diff --git a/tests/diagnostics/interfaces/anyvalue-size-validation.slang b/tests/diagnostics/interfaces/anyvalue-size-validation.slang
index 1ebf7f4c3..f2ed52d0c 100644
--- a/tests/diagnostics/interfaces/anyvalue-size-validation.slang
+++ b/tests/diagnostics/interfaces/anyvalue-size-validation.slang
@@ -26,6 +26,6 @@ RWStructuredBuffer<uint> output;
 [numthreads(4, 1, 1)]
 void main()
 {
-    S s;
+    S s = S();
     output[0] = test(s).a;
-}
\ No newline at end of file
+}
diff --git a/tests/diagnostics/uninitialized-globals.slang b/tests/diagnostics/uninitialized-globals.slang
new file mode 100644
index 000000000..314881a80
--- /dev/null
+++ b/tests/diagnostics/uninitialized-globals.slang
@@ -0,0 +1,48 @@
+//TEST:SIMPLE(filecheck=CHK): -target spirv
+
+// Using groupshared variables
+groupshared float4 gsConstexpr = float4(1.0f);
+groupshared float4 gsUndefined;
+
+// OK
+float use_constexpr_initialized_gs()
+{
+    return gsConstexpr.x;
+}
+
+float use_undefined_gs()
+{
+    //CHK-DAG: warning 41017: use of uninitialized global variable 'gsUndefined'
+    return gsUndefined.x;
+}
+
+// Using static variables
+static const float cexprInitialized = 1.0f;
+static float writtenNever;
+static float writtenLater;
+
+// OK
+float use_initialized_static()
+{
+    return cexprInitialized;
+}
+
+// Should detect this and treat it as a store
+void write_to_later()
+{
+    writtenLater = 1.0f;
+}
+
+float use_never_written()
+{
+    //CHK-DAG: warning 41017: use of uninitialized global variable 'writtenNever'
+    return writtenNever;
+}
+
+// OK because of prior store
+float use_later_writte()
+{
+    return writtenLater;
+}
+
+//CHK-NOT: warning 41017
diff --git a/tests/diagnostics/uninitialized.slang b/tests/diagnostics/uninitialized-local-variables.slang
index 4779f45c9..5a2119f53 100644
--- a/tests/diagnostics/uninitialized.slang
+++ b/tests/diagnostics/uninitialized-local-variables.slang
@@ -1,14 +1,5 @@
 //TEST:SIMPLE(filecheck=CHK): -target spirv
 
-// TODO:
-// * warn potentially uninitialized variables (control flow)
-// * warn partially uninitialized variables (structs, arrays, etc.)
-// * warn uninitialized fields in constructors
-
-///////////////////////////////////
-// Uninitialized local variables //
-///////////////////////////////////
-
 // Should not warn here (unconditionalBranch)
 float3 unconditional(int mode)
 {
@@ -157,107 +148,4 @@ float structs()
     return result;
 }
 
-////////////////////////////////////
-// Uninitialized global variables //
-////////////////////////////////////
-
-// Using groupshared variables
-groupshared float4 gsConstexpr = float4(1.0f);
-groupshared float4 gsUndefined;
-
-// OK
-float use_constexpr_initialized_gs()
-{
-    return gsConstexpr.x;
-}
-
-float use_undefined_gs()
-{
-    //CHK-DAG: warning 41017: use of uninitialized global variable 'gsUndefined'
-    return gsUndefined.x;
-}
-
-// Using static variables
-static const float cexprInitialized = 1.0f;
-static float writtenNever;
-static float writtenLater;
-
-// OK
-float use_initialized_static()
-{
-    return cexprInitialized;
-}
-
-// Should detect this and treat it as a store
-void write_to_later()
-{
-    writtenLater = 1.0f;
-}
-
-float use_never_written()
-{
-    //CHK-DAG: warning 41017: use of uninitialized global variable 'writtenNever'
-    return writtenNever;
-}
-
-// OK because of prior store
-float use_later_writte()
-{
-    return writtenLater;
-}
-
-//////////////////////////////////
-// Uninitialized out parameters //
-//////////////////////////////////
-
-// Using before assigning
-float regular_undefined_use(out float3 v)
-{
-    //CHK-DAG: warning 41015: use of uninitialized out parameter 'v'
-    float r = v.x + 1.0;
-    
-    //CHK-DAG: warning 41018: returning without initializing out parameter 'v'
-    return r;
-}
-
-// Returning before assigning
-float returning_undefined_use(out float x)
-{
-    //CHK-DAG: warning 41018: returning without initializing out parameter 'x'
-    return 0;
-}
-
-// Implicit, still returning before assigning
-void implicit_undefined_use(out float x) 
-{
-    //CHK-DAG: warning 41018: returning without initializing out parameter 'x'
-}
-
-// Warn on potential return paths
-void control_flow_undefined(bool b, out float y)
-{
-    if(b)
-    {
-        //CHK-DAG: warning 41018: returning without initializing out parameter 'y'
-        return;
-    }
-    y = 0;
-    return;
-}
-
-// No warnings if all paths are fine
-void control_flow_defined(bool b, out float y)
-{
-    if(b)
-    {
-        unused(y);
-        return;
-    }
-    y = 0;
-    return;
-}
-
-//CHK-NOT: warning 41015
 //CHK-NOT: warning 41016
-//CHK-NOT: warning 41017
-//CHK-NOT: warning 41018
diff --git a/tests/diagnostics/uninitialized-out-parameters.slang b/tests/diagnostics/uninitialized-out-parameters.slang
new file mode 100644
index 000000000..9714a4b76
--- /dev/null
+++ b/tests/diagnostics/uninitialized-out-parameters.slang
@@ -0,0 +1,51 @@
+//TEST:SIMPLE(filecheck=CHK): -target spirv
+
+// Using before assigning
+float regular_undefined_use(out float3 v)
+{
+    //CHK-DAG: warning 41015: use of uninitialized out parameter 'v'
+    float r = v.x + 1.0;
+    
+    //CHK-DAG: warning 41018: returning without initializing out parameter 'v'
+    return r;
+}
+
+// Returning before assigning
+float returning_undefined_use(out float x)
+{
+    //CHK-DAG: warning 41018: returning without initializing out parameter 'x'
+    return 0;
+}
+
+// Implicit, still returning before assigning
+void implicit_undefined_use(out float x) 
+{
+    //CHK-DAG: warning 41018: returning without initializing out parameter 'x'
+}
+
+// Warn on potential return paths
+void control_flow_undefined(bool b, out float y)
+{
+    if(b)
+    {
+        //CHK-DAG: warning 41018: returning without initializing out parameter 'y'
+        return;
+    }
+    y = 0;
+    return;
+}
+
+// No warnings if all paths are fine
+void control_flow_defined(bool b, out float y)
+{
+    if(b)
+    {
+        unused(y);
+        return;
+    }
+    y = 0;
+    return;
+}
+
+//CHK-NOT: warning 41015
+//CHK-NOT: warning 41018
diff --git a/tests/diagnostics/uninitialized-out.slang.expected b/tests/diagnostics/uninitialized-out.slang.expected
deleted file mode 100644
index 5846c12df..000000000
--- a/tests/diagnostics/uninitialized-out.slang.expected
+++ /dev/null
@@ -1,20 +0,0 @@
-result code = -1
-standard error = {
-tests/diagnostics/uninitialized-out.slang(6): error 41015: use of uninitialized value 'v'
-    float r = v.x + 1.0;
-                ^
-tests/diagnostics/uninitialized-out.slang(8): warning 41016: returning without initializing out parameter 'v'
-    return r;
-    ^~~~~~
-tests/diagnostics/uninitialized-out.slang(14): warning 41016: returning without initializing out parameter 'x'
-    return 0;
-    ^~~~~~
-tests/diagnostics/uninitialized-out.slang(18): warning 41016: returning without initializing out parameter 'x'
-void baz(out float x) {}
-                       ^
-tests/diagnostics/uninitialized-out.slang(25): warning 41016: returning without initializing out parameter 'y'
-        return;
-        ^~~~~~
-}
-standard output = {
-}
diff --git a/tests/diagnostics/uninitialized-use-functions.slang b/tests/diagnostics/uninitialized-use-functions.slang
new file mode 100644
index 000000000..82e7a04a8
--- /dev/null
+++ b/tests/diagnostics/uninitialized-use-functions.slang
@@ -0,0 +1,113 @@
+//TEST:SIMPLE(filecheck=CHK): -target spirv
+
+// Both out and inout parameters
+// should have this treated as writes
+void out_test(int tmp, out int x)
+{
+    x = tmp;
+}
+
+// Permuting arguments to ensure that
+// the correct argument is checked
+void inout_test(inout int x, int tmp)
+{
+    x = tmp;
+}
+
+// __ref parameters should also be fine
+void ref_test(__ref int x, int tmp)
+{
+    x = tmp;
+}
+
+void undefined_function_use()
+{
+    int x;
+    int tmp = 1;
+
+    //CHK-DAG: warning 41016: use of uninitialized variable 'x'
+    out_test(x, tmp);
+    
+    //CHK-DAG: warning 41016: use of uninitialized variable 'x'
+    inout_test(tmp, x);
+}
+
+void out_function_use()
+{
+    int x;
+    int tmp = 1;
+
+    // Acts as a write
+    out_test(tmp, x);
+
+    // Rest are fine now
+    out_test(x, tmp);
+    inout_test(tmp, x);
+}
+
+void inout_function_use()
+{
+    int x;
+    int tmp = 1;
+
+    // Acts as a write
+    inout_test(x, tmp);
+
+    // Rest are fine now
+    out_test(x, tmp);
+    inout_test(tmp, x);
+}
+
+void ref_function_use()
+{
+    int x;
+    int tmp = 1;
+
+    // Acts as a write
+    ref_test(x, tmp);
+
+    // Rest are fine now
+    out_test(x, tmp);
+    inout_test(tmp, x);
+}
+
+// Likewise for generic functions
+static int ord_gen_result;
+
+__generic<T>
+void ordinary_generic(T x)
+{
+    ord_gen_result = __slang_noop_cast<int, T>(x);
+}
+
+__generic<T>
+void unordinary_generic(out T x)
+{
+    x = __slang_noop_cast<T, int>(1);
+}
+
+void undefined_generic_use()
+{
+    int x;
+
+    //CHK-DAG: warning 41016: use of uninitialized variable 'x'
+    ordinary_generic(x);
+}
+
+void ok_generic_use()
+{
+    int x;
+    unordinary_generic(x);
+    ordinary_generic(x);
+}
+
+// Check proper handling of aliases passed
+void f()
+{
+    int3 dim;
+
+    // Should have no warnings
+    out_test(1, dim.x);
+}
+
+//CHK-NOT: warning 41016
diff --git a/tests/language-feature/types/is-on-type.slang b/tests/language-feature/types/is-on-type.slang
index e9dd48fcf..728f759ad 100644
--- a/tests/language-feature/types/is-on-type.slang
+++ b/tests/language-feature/types/is-on-type.slang
@@ -18,7 +18,7 @@ struct A : I
 
 struct B : I
 {
-    float2 f2;
+    float2 f2 = float2(0.0f);
 };
 
 func test<T : I>(T t) -> int
@@ -42,4 +42,4 @@ void computeMain()
     B b;
     // CHECK: 2
     outputBuffer[0] = test(b);
-}
\ No newline at end of file
+}