* Disallow passing qvector(s) arguments to custom operations.

Signed-off-by: Pradnya Khalate <[email protected]>

python/cudaq/kernel/ast_bridge.py

@@ -1826,7 +1826,11 @@ def bodyBuilder(iterVal):
                 targets = [self.popValue() for _ in range(numTargets)]
                 targets.reverse()
 
-                self.checkControlAndTargetTypes([], targets)
+                for i, t in enumerate(targets):
+                    if not quake.RefType.isinstance(t.type):
+                        self.emitFatalError(
+                            f'invalid target operand {i}, broadcasting is not supported on custom operations.'
+                        )
 
                 globalName = f'{nvqppPrefix}{node.func.id}_generator_{numTargets}.rodata'
 
@@ -2678,6 +2682,12 @@ def bodyBuilder(iterVal):
                 targets = [self.popValue() for _ in range(numTargets)]
                 targets.reverse()
 
+                for i, t in enumerate(targets):
+                    if not quake.RefType.isinstance(t.type):
+                        self.emitFatalError(
+                            f'invalid target operand {i}, broadcasting is not supported on custom operations.'
+                        )
+
                 globalName = f'{nvqppPrefix}{node.func.value.id}_generator_{numTargets}.rodata'
 
                 currentST = SymbolTable(self.module.operation)

python/tests/custom/test_custom_operations.py

@@ -230,6 +230,45 @@ def bell():
         error)
 
 
+def test_bug_2452():
+    cudaq.register_operation("custom_i", np.array([1, 0, 0, 1]))
+
+    @cudaq.kernel
+    def kernel1():
+        qubits = cudaq.qvector(2)
+        custom_i(qubits)
+
+    with pytest.raises(RuntimeError) as error:
+        kernel1.compile()
+    assert 'broadcasting is not supported on custom operations' in repr(error)
+
+    cudaq.register_operation("custom_x", np.array([0, 1, 1, 0]))
+
+    @cudaq.kernel
+    def kernel2():
+        qubit = cudaq.qubit()
+        ancilla = cudaq.qvector(2)
+        x(ancilla)
+        custom_x.ctrl(ancilla, qubit)  # `controls` can be `qvector`
+
+    counts = cudaq.sample(kernel2)
+    assert len(counts) == 1 and '111' in counts
+
+    cudaq.register_operation(
+        "custom_cz", np.array([1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0,
+                               -1]))
+
+    @cudaq.kernel
+    def kernel3():
+        qubits = cudaq.qvector(2)
+        custom_cz(qubits)
+
+    with pytest.raises(RuntimeError) as error:
+        cudaq.sample(kernel3)
+    assert 'invalid number of arguments (1) passed to custom_cz (requires 2 arguments)' in repr(
+        error)
+
+
 # leave for gdb debugging
 if __name__ == "__main__":
     loc = os.path.abspath(__file__)