Fix for default initialization with generic field (#2168)

* #include an absolute path didn't work - because paths were taken to always be relative.

* Fix for = {} initialization with a field that is generic type parameter.

* Handling for if a non type is passed to a generic parameter which requires a type.

* Small comment improvements.
Fix some tab issues.

* This fixes the matrix.slang issue. Move the matrix.slang test into bugs as generic-default-matrix.slang

8 files changed, 93 insertions, 13 deletions

diff --git a/source/slang/slang-check-type.cpp b/source/slang/slang-check-type.cpp
index 6c9b0c8ca..bd7b89e16 100644
--- a/source/slang/slang-check-type.cpp
+++ b/source/slang/slang-check-type.cpp
@@ -172,10 +172,11 @@ namespace Slang
         DiagnosticSink* diagSink)
     {
         Type* type = typeExp.type;
-        if(!type && typeExp.exp)
-        {
-            auto expr = typeExp.exp;
+        auto originalExpr = typeExp.exp;
+        auto expr = originalExpr;
 
+        if(!type && expr)
+        {
             expr = maybeResolveOverloadedExpr(expr, LookupMask::type, diagSink);
 
             if(auto typeType = as<TypeType>(expr->type))
@@ -186,6 +187,29 @@ namespace Slang
 
         if (!type)
         {
+            // Only output diagnostic if we have a sink.
+            if (diagSink)
+            {
+                // This function *can* be called with typeExp with both exp and type = nullptr.
+                // Previous behavior didn't output a diagnostic if originalExpr was null, so this keeps that behavior.
+                // 
+                // Additional we check for ErrorType on expr, because if it's set a diagnostic has already been output via
+                // previous code or via maybeResolveOverloadedExpr.
+                if (originalExpr && (expr == nullptr || as<ErrorType>(expr->type) == nullptr))
+                {
+                    // The diagnostic for expectedAType wants to say what it 'got'.
+                    // The solution given here, currently is to just use the node name.
+                    // How useful that might be could depend, and perhaps some other mechanism
+                    // that catagorized 'what' the wrong thing was is. For now this seems sufficient.
+                    //
+                    // Note that use originalExpr (not expr) because we want original expr for diagnostic.
+
+                    // Get the AST node type info, so we can output a 'got' name
+                    auto info = ASTClassInfo::getInfo(originalExpr->astNodeType);
+                    diagSink->diagnose(originalExpr, Diagnostics::expectedAType, info->m_name);
+                }
+            }
+
             if (outProperType)
             {
                 *outProperType = nullptr;
diff --git a/source/slang/slang-lower-to-ir.cpp b/source/slang/slang-lower-to-ir.cpp
index b2a71a2e0..9ec8c1c71 100644
--- a/source/slang/slang-lower-to-ir.cpp
+++ b/source/slang/slang-lower-to-ir.cpp
@@ -3016,15 +3016,17 @@ struct ExprLoweringVisitorBase : ExprVisitor<Derived, LoweredValInfo>
         UNREACHABLE_RETURN(LoweredValInfo());
     }
 
-    LoweredValInfo getDefaultVal(VarDeclBase* decl)
+    LoweredValInfo getDefaultVal(DeclRef<VarDeclBase> decl)
     {
-        if(auto initExpr = decl->initExpr)
+        if(auto initExpr = decl.getDecl()->initExpr)
         {
             return lowerRValueExpr(context, initExpr);
         }
         else
         {
-            return getDefaultVal(decl->type);
+            Type* type = decl.substitute(getASTBuilder(), decl.getDecl()->type);
+            SLANG_ASSERT(type);
+            return getDefaultVal(type);
         }
     }
 
diff --git a/tests/experiments/generic/matrix.slang b/tests/bugs/generic-default-matrix.slang
index c55c7be33..47fbe520e 100644
--- a/tests/experiments/generic/matrix.slang
+++ b/tests/bugs/generic-default-matrix.slang
@@ -1,9 +1,4 @@
-//DISABLE_TEST(compute):COMPARE_COMPUTE_EX:-slang -compute -shaderobj
-
-/* A test to use generics around resource/built in types. 
-
-CRASHES the compiler. 
- */
+//TEST(compute):COMPARE_COMPUTE_EX:-slang -compute -shaderobj
 
 //TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):out,name outputBuffer
 RWStructuredBuffer<int> outputBuffer;
@@ -20,6 +15,6 @@ void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
 
     Another<2, 4> a = {};
    
-	outputBuffer[index] = index;
+	outputBuffer[index] = index + a.values[0].x;
 }
 
diff --git a/tests/bugs/generic-default-matrix.slang.expected.txt b/tests/bugs/generic-default-matrix.slang.expected.txt
new file mode 100644
index 000000000..bc856dafa
--- /dev/null
+++ b/tests/bugs/generic-default-matrix.slang.expected.txt
@@ -0,0 +1,4 @@
+0
+1
+2
+3
diff --git a/tests/bugs/generic-default-value.slang b/tests/bugs/generic-default-value.slang
new file mode 100644
index 000000000..b3805e317
--- /dev/null
+++ b/tests/bugs/generic-default-value.slang
@@ -0,0 +1,23 @@
+//TEST(compute):COMPARE_COMPUTE_EX:-slang -compute -shaderobj 
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):out,name outputBuffer
+RWStructuredBuffer<int> outputBuffer;
+
+/* Tests purpose is to confirm that use of `= {}` initialization 
+works with a generic */
+
+struct Check<T>
+{
+    T v;
+};
+
+[numthreads(4, 1, 1)]
+void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
+{
+    int index = dispatchThreadID.x;
+
+    Check<float> v = {};
+    
+    outputBuffer[index] = index + v.v; 
+}
+
diff --git a/tests/bugs/generic-default-value.slang.expected.txt b/tests/bugs/generic-default-value.slang.expected.txt
new file mode 100644
index 000000000..bc856dafa
--- /dev/null
+++ b/tests/bugs/generic-default-value.slang.expected.txt
@@ -0,0 +1,4 @@
+0
+1
+2
+3
diff --git a/tests/diagnostics/generic-invalid-type-specialization.slang b/tests/diagnostics/generic-invalid-type-specialization.slang
new file mode 100644
index 000000000..28d155643
--- /dev/null
+++ b/tests/diagnostics/generic-invalid-type-specialization.slang
@@ -0,0 +1,20 @@
+//DIAGNOSTIC_TEST:SIMPLE:
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):out,name outputBuffer
+RWStructuredBuffer<int> outputBuffer;
+
+struct Check<T>
+{
+    T v;
+};
+
+[numthreads(4, 1, 1)]
+void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
+{
+    int index = dispatchThreadID.x;
+
+    // Invalid as should only accept a type
+    Check<2 + 2> v; 
+    
+    outputBuffer[index] = index; 
+}
diff --git a/tests/diagnostics/generic-invalid-type-specialization.slang.expected b/tests/diagnostics/generic-invalid-type-specialization.slang.expected
new file mode 100644
index 000000000..b3c75c760
--- /dev/null
+++ b/tests/diagnostics/generic-invalid-type-specialization.slang.expected
@@ -0,0 +1,8 @@
+result code = -1
+standard error = {
+tests/diagnostics/generic-invalid-type-specialization.slang(17): error 30060: expected a type, got a 'InfixExpr'
+    Check<2 + 2> v;
+            ^
+}
+standard output = {
+}