[analyzer] exploded-graph-rewriter: Implement program point tags.

Keep them on a separate line for more visibility.

Differential Revision: https://reviews.llvm.org/D63965

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@364864 91177308-0d34-0410-b5e6-96231b3b80d8

test/Analysis/exploded-graph-rewriter/program_points.dot

@@ -41,6 +41,14 @@ Node0x1 [shape=record,label=
 // CHECK-SAME:     </td>
 // CHECK-SAME:     <td>x</td>
 // CHECK-SAME:   </tr>
+// CHECK-SAME:   <tr>
+// CHECK-SAME:     <td width="0">
+// CHECK-SAME:     </td>
+// CHECK-SAME:     <td colspan="2" align="left">
+// CHECK-SAME:       <b>Tag: </b>
+// CHECK-SAME:       <font color="crimson">ExprEngine : Clean Node</font>
+// CHECK-SAME:     </td>
+// CHECK-SAME:   </tr>
 // CHECK-SAME: </table>
 Node0x2 [shape=record,label=
  "{
@@ -56,7 +64,7 @@ Node0x2 [shape=record,label=
           "line": 4,
           "column": 5
         },
-        "tag": null
+        "tag": "ExprEngine : Clean Node"
       }
     ]}
 \l}"];

utils/analyzer/exploded-graph-rewriter.py

@@ -387,6 +387,12 @@ def visit_program_point(self, p):
                        '<font color="%s">%s</font></td></tr>'
                        % (color, p.kind))
 
+        if p.tag is not None:
+            self._dump('<tr><td width="0"></td>'
+                       '<td colspan="2" align="left">'
+                       '<b>Tag: </b> <font color="crimson">'
+                       '%s</font></td></tr>' % p.tag)
+
     def visit_environment(self, e, prev_e=None):
         self._dump('<table border="0">')