Clone name hint decoration when emiting Undefined

source/slang/slang-ir-ssa.cpp

@@ -694,6 +694,7 @@ IRInst* readVarRec(ConstructSSAContext* context, SSABlockInfo* blockInfo, IRVar*
 
             auto type = var->getDataType()->getValueType();
             val = blockInfo->builder.emitUndefined(type);
+            cloneRelevantDecorations(var, val);
         }
         else if (!multiplePreds)
         {
@@ -776,6 +777,7 @@ IRInst* readVar(ConstructSSAContext* context, SSABlockInfo* blockInfo, IRVar* va
         //
         auto type = var->getDataType()->getValueType();
         val = blockInfo->builder.emitUndefined(type);
+        cloneRelevantDecorations(var, val);
         writeVar(context, blockInfo, var, val);
         return val;
     }

tests/diagnostics/uninitialized-variable-name-in-error-message.slang

@@ -0,0 +1,37 @@
+//TEST:SIMPLE(filecheck=CHK):
+
+// Test if the variable name is a part of the error message
+// when it is used inside of for-loop
+
+RWStructuredBuffer<float> gInput;
+RWStructuredBuffer<float> outputBuffer;
+
+//CHK-DAG: ([[#@LINE+1]]): warning 41016: use of uninitialized variable 'a'
+float func1() { float a; return a; }
+
+//CHK-DAG: ([[#@LINE+1]]): warning 41016: use of uninitialized variable 'b'
+float func2() { float b; return b; }
+
+int test(int inVal)
+{
+    return inVal;
+}
+
+[Shader("compute")]
+[NumThreads(4, 1, 1)]
+void computeMain(int3 dispatchThreadID : SV_DispatchThreadID)
+{
+    int tid = dispatchThreadID.x;
+    int inVal1; // intentionally uninitialized
+    int inVal2; // intentionally uninitialized
+
+    for (int i = 0; i <2; ++i)
+    {
+        // CHK-DAG: ([[#@LINE+1]]): warning 41016: use of uninitialized variable 'inVal1'
+        int outVal = test(inVal1);
+
+        // CHK-DAG: ([[#@LINE+1]]): warning 41016: use of uninitialized variable 'inVal2'
+        outVal += test(inVal2);
+        outputBuffer[tid] = outVal;
+    }
+}