Fix CheckMap pass target handling (Qiskit#9929)

In the recently merged 5672c70 the
CheckMap transpiler pass had issues when handling some Target inputs
(which was added as a supported type in that PR). These issues were
actually pointed out in code review during Qiskit#9263 but the follow up
slipped through. This commit makes the required fixes and also updates
the signature of the CheckMap to match the other changes made in Qiskit#9263.

qiskit/transpiler/passes/utils/check_map.py

@@ -13,6 +13,7 @@
 """Check if a DAG circuit is already mapped to a coupling map."""
 
 from qiskit.transpiler.basepasses import AnalysisPass
+from qiskit.transpiler.target import Target
 from qiskit.circuit.controlflow import ControlFlowOp
 
 
@@ -27,30 +28,24 @@ class CheckMap(AnalysisPass):
     for a target use the :class:`~.CheckGateDirection` pass instead.
     """
 
-    def __init__(self, coupling_map=None, target=None):
+    def __init__(self, coupling_map):
         """CheckMap initializer.
 
         Args:
-            coupling_map (CouplingMap): Directed graph representing a coupling map.
-            target (Target): A target representing the target backend, if both
-                ``coupling_map`` and this are specified then this argument will take
-                precedence and ``coupling_map`` will be ignored.
+            coupling_map (Union[CouplingMap, Target]): Directed graph representing a coupling map.
         """
         super().__init__()
-        if coupling_map is None and target is None:
+        if isinstance(coupling_map, Target):
+            cmap = coupling_map.build_coupling_map()
+        else:
+            cmap = coupling_map
+        if cmap is None:
             self.qargs = None
         else:
             self.qargs = set()
-            if target is not None:
-                if target.qargs is not None:
-                    for edge in target.qargs:
-                        if len(edge) == 2:
-                            self.qargs.add(edge)
-                            self.qargs.add((edge[1], edge[0]))
-            else:
-                for edge in coupling_map.get_edges():
-                    self.qargs.add(edge)
-                    self.qargs.add((edge[1], edge[0]))
+            for edge in cmap.get_edges():
+                self.qargs.add(edge)
+                self.qargs.add((edge[1], edge[0]))
 
     def run(self, dag):
         """Run the CheckMap pass on `dag`.

qiskit/transpiler/preset_passmanagers/common.py

@@ -273,7 +273,10 @@ def _run_post_layout_condition(property_set):
         return False
 
     routing = PassManager()
-    routing.append(CheckMap(coupling_map, target=target))
+    if target is not None:
+        routing.append(CheckMap(target))
+    else:
+        routing.append(CheckMap(coupling_map))
 
     def _swap_condition(property_set):
         return not property_set["is_swap_mapped"]

qiskit/transpiler/preset_passmanagers/level1.py

@@ -121,7 +121,7 @@ def _vf2_match_not_found(property_set):
     _choose_layout_0 = (
         []
         if pass_manager_config.layout_method
-        else [TrivialLayout(coupling_map_layout), CheckMap(coupling_map, target=target)]
+        else [TrivialLayout(coupling_map_layout), CheckMap(coupling_map_layout)]
     )
 
     _choose_layout_1 = (

test/python/transpiler/test_check_map.py

@@ -59,7 +59,7 @@ def test_trivial_nop_map_target(self):
         circuit.h(qr)
         target = Target()
         dag = circuit_to_dag(circuit)
-        pass_ = CheckMap(target=target)
+        pass_ = CheckMap(target)
         pass_.run(dag)
         self.assertTrue(pass_.property_set["is_swap_mapped"])
 
@@ -120,7 +120,7 @@ def test_swap_mapped_false_target(self):
         target.add_instruction(CXGate(), {(0, 2): None, (2, 1): None})
         dag = circuit_to_dag(circuit)
 
-        pass_ = CheckMap(target=target)
+        pass_ = CheckMap(target)
         pass_.run(dag)
 
         self.assertFalse(pass_.property_set["is_swap_mapped"])

test/python/visualization/references/pass_manager_standard.dot

@@ -53,39 +53,37 @@ fontname=helvetica;
 label="[5] ";
 labeljust=l;
 16 [color=red, fontname=helvetica, label=CheckMap, shape=rectangle];
-17 [color=black, fontname=helvetica, fontsize=10, label=coupling_map, shape=ellipse, style=dashed];
+17 [color=black, fontname=helvetica, fontsize=10, label=coupling_map, shape=ellipse, style=solid];
 17 -> 16;
-18 [color=black, fontname=helvetica, fontsize=10, label=target, shape=ellipse, style=dashed];
-18 -> 16;
 12 -> 16;
 }
 
-subgraph cluster_19 {
+subgraph cluster_18 {
 fontname=helvetica;
 label="[6] do_while";
 labeljust=l;
-20 [color=blue, fontname=helvetica, label=BarrierBeforeFinalMeasurements, shape=rectangle];
-16 -> 20;
+19 [color=blue, fontname=helvetica, label=BarrierBeforeFinalMeasurements, shape=rectangle];
+16 -> 19;
 }
 
-subgraph cluster_21 {
+subgraph cluster_20 {
 fontname=helvetica;
 label="[7] ";
 labeljust=l;
-22 [color=blue, fontname=helvetica, label=GateDirection, shape=rectangle];
-23 [color=black, fontname=helvetica, fontsize=10, label=coupling_map, shape=ellipse, style=solid];
-23 -> 22;
-24 [color=black, fontname=helvetica, fontsize=10, label=target, shape=ellipse, style=dashed];
-24 -> 22;
-20 -> 22;
+21 [color=blue, fontname=helvetica, label=GateDirection, shape=rectangle];
+22 [color=black, fontname=helvetica, fontsize=10, label=coupling_map, shape=ellipse, style=solid];
+22 -> 21;
+23 [color=black, fontname=helvetica, fontsize=10, label=target, shape=ellipse, style=dashed];
+23 -> 21;
+19 -> 21;
 }
 
-subgraph cluster_25 {
+subgraph cluster_24 {
 fontname=helvetica;
 label="[8] ";
 labeljust=l;
-26 [color=blue, fontname=helvetica, label=RemoveResetInZeroState, shape=rectangle];
-22 -> 26;
+25 [color=blue, fontname=helvetica, label=RemoveResetInZeroState, shape=rectangle];
+21 -> 25;
 }
 
 }

test/python/visualization/references/pass_manager_style.dot

@@ -53,39 +53,37 @@ fontname=helvetica;
 label="[5] ";
 labeljust=l;
 16 [color=green, fontname=helvetica, label=CheckMap, shape=rectangle];
-17 [color=black, fontname=helvetica, fontsize=10, label=coupling_map, shape=ellipse, style=dashed];
+17 [color=black, fontname=helvetica, fontsize=10, label=coupling_map, shape=ellipse, style=solid];
 17 -> 16;
-18 [color=black, fontname=helvetica, fontsize=10, label=target, shape=ellipse, style=dashed];
-18 -> 16;
 12 -> 16;
 }
 
-subgraph cluster_19 {
+subgraph cluster_18 {
 fontname=helvetica;
 label="[6] do_while";
 labeljust=l;
-20 [color=blue, fontname=helvetica, label=BarrierBeforeFinalMeasurements, shape=rectangle];
-16 -> 20;
+19 [color=blue, fontname=helvetica, label=BarrierBeforeFinalMeasurements, shape=rectangle];
+16 -> 19;
 }
 
-subgraph cluster_21 {
+subgraph cluster_20 {
 fontname=helvetica;
 label="[7] ";
 labeljust=l;
-22 [color=blue, fontname=helvetica, label=GateDirection, shape=rectangle];
-23 [color=black, fontname=helvetica, fontsize=10, label=coupling_map, shape=ellipse, style=solid];
-23 -> 22;
-24 [color=black, fontname=helvetica, fontsize=10, label=target, shape=ellipse, style=dashed];
-24 -> 22;
-20 -> 22;
+21 [color=blue, fontname=helvetica, label=GateDirection, shape=rectangle];
+22 [color=black, fontname=helvetica, fontsize=10, label=coupling_map, shape=ellipse, style=solid];
+22 -> 21;
+23 [color=black, fontname=helvetica, fontsize=10, label=target, shape=ellipse, style=dashed];
+23 -> 21;
+19 -> 21;
 }
 
-subgraph cluster_25 {
+subgraph cluster_24 {
 fontname=helvetica;
 label="[8] ";
 labeljust=l;
-26 [color=grey, fontname=helvetica, label=RemoveResetInZeroState, shape=rectangle];
-22 -> 26;
+25 [color=grey, fontname=helvetica, label=RemoveResetInZeroState, shape=rectangle];
+21 -> 25;
 }
 
 }