r365409 - [analyzer] exploded-graph-rewriter: Implement a single-path mode.

[Artem Dergachev via cfe-commits]

Author: dergachev
Date: Mon Jul  8 16:54:11 2019
New Revision: 365409

URL: http://llvm.org/viewvc/llvm-project?rev=365409&view=rev
Log:
[analyzer] exploded-graph-rewriter: Implement a single-path mode.

Instead of rewriting the whole graph, rewrite the leftmost path in the
graph. Useful for trimmed graphs that are still too large to display due
to multiple equivalent reports mixed into them.

Differential Revision: https://reviews.llvm.org/D64263

Added:
    cfe/trunk/test/Analysis/exploded-graph-rewriter/explorers.dot
Modified:
    cfe/trunk/utils/analyzer/exploded-graph-rewriter.py

Added: cfe/trunk/test/Analysis/exploded-graph-rewriter/explorers.dot
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/exploded-graph-rewriter/explorers.dot?rev=365409&view=auto
==============================================================================
--- cfe/trunk/test/Analysis/exploded-graph-rewriter/explorers.dot (added)
+++ cfe/trunk/test/Analysis/exploded-graph-rewriter/explorers.dot Mon Jul  8 16:54:11 2019
@@ -0,0 +1,37 @@
+// RUN: %exploded_graph_rewriter %s \
+// RUN:     | FileCheck %s -check-prefixes=CHECK,BASIC
+// RUN: %exploded_graph_rewriter -s %s \
+// RUN:     | FileCheck %s -check-prefixes=CHECK,SINGLE
+
+// FIXME: Substitution doesn't seem to work on Windows.
+// UNSUPPORTED: system-windows
+
+Node0x1 [shape=record,label=
+ "{{ "node_id": 1, "pointer": "0x1", "has_report": false, "is_sink": false,
+      "program_state": null, "program_points": []}\l}"];
+
+Node0x2 [shape=record,label=
+ "{{ "node_id": 2, "pointer": "0x2", "has_report": false, "is_sink": false,
+      "program_state": null, "program_points": []}\l}"];
+
+Node0x3 [shape=record,label=
+ "{{ "node_id": 3, "pointer": "0x3", "has_report": false, "is_sink": false,
+      "program_state": null, "program_points": []}\l}"];
+
+Node0x4 [shape=record,label=
+ "{{ "node_id": 4, "pointer": "0x4", "has_report": false, "is_sink": false,
+      "program_state": null, "program_points": []}\l}"];
+
+// CHECK: Node0x1 -> Node0x2;
+Node0x1 -> Node0x2;
+
+// BASIC: Node0x1 -> Node0x3;
+// SINGLE-NOT: Node0x1 -> Node0x3;
+Node0x1 -> Node0x3;
+
+// CHECK: Node0x2 -> Node0x4;
+Node0x2 -> Node0x4;
+
+// BASIC: Node0x3 -> Node0x4;
+// SINGLE-NOT: Node0x3 -> Node0x4;
+Node0x3 -> Node0x4;

Modified: cfe/trunk/utils/analyzer/exploded-graph-rewriter.py
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/utils/analyzer/exploded-graph-rewriter.py?rev=365409&r1=365408&r2=365409&view=diff
==============================================================================
--- cfe/trunk/utils/analyzer/exploded-graph-rewriter.py (original)
+++ cfe/trunk/utils/analyzer/exploded-graph-rewriter.py Mon Jul  8 16:54:11 2019
@@ -804,8 +804,7 @@ class DotDumpVisitor(object):
 #===-----------------------------------------------------------------------===#
 
 
-# A class that encapsulates traversal of the ExplodedGraph. Different explorer
-# kinds could potentially traverse specific sub-graphs.
+# BasicExplorer explores the whole graph in no particular order.
 class BasicExplorer(object):
     def __init__(self):
         super(BasicExplorer, self).__init__()
@@ -821,6 +820,39 @@ class BasicExplorer(object):
         visitor.visit_end_of_graph()
 
 
+# SinglePathExplorer traverses only a single path - the leftmost path
+# from the root. Useful when the trimmed graph is still too large
+# due to a large amount of equivalent reports.
+class SinglePathExplorer(object):
+    def __init__(self):
+        super(SinglePathExplorer, self).__init__()
+
+    def explore(self, graph, visitor):
+        visitor.visit_begin_graph(graph)
+
+        # Keep track of visited nodes in order to avoid loops.
+        visited = set()
+        node_id = graph.root_id
+        while True:
+            visited.add(node_id)
+            node = graph.nodes[node_id]
+            logging.debug('Visiting ' + node_id)
+            visitor.visit_node(node)
+            if len(node.successors) == 0:
+                break
+
+            succ_id = node.successors[0]
+            succ = graph.nodes[succ_id]
+            logging.debug('Visiting edge: %s -> %s ' % (node_id, succ_id))
+            visitor.visit_edge(node, succ)
+            if succ_id in visited:
+                break
+
+            node_id = succ_id
+
+        visitor.visit_end_of_graph()
+
+
 #===-----------------------------------------------------------------------===#
 # The entry point to the script.
 #===-----------------------------------------------------------------------===#
@@ -836,6 +868,11 @@ def main():
     parser.add_argument('-d', '--diff', action='store_const', dest='diff',
                         const=True, default=False,
                         help='display differences between states')
+    parser.add_argument('-s', '--single-path', action='store_const',
+                        dest='single_path', const=True, default=False,
+                        help='only display the leftmost path in the graph '
+                             '(useful for trimmed graphs that still '
+                             'branch too much)')
     parser.add_argument('--dark', action='store_const', dest='dark',
                         const=True, default=False,
                         help='dark mode')
@@ -851,8 +888,9 @@ def main():
             raw_line = raw_line.strip()
             graph.add_raw_line(raw_line)
 
-    explorer = BasicExplorer()
+    explorer = SinglePathExplorer() if args.single_path else BasicExplorer()
     visitor = DotDumpVisitor(args.diff, args.dark, args.gray)
+
     explorer.explore(graph, visitor)