Python: Add ConsecutiveTimestamps test

This one is potentially a bit iffy -- it checks for a very powerful
property (that implies many of the other queries), but as the test
results show, it can produce false positives when there is in fact no
problem. We may want to get rid of it entirely, if it becomes too noisy.

Author: tausbn

python/ql/test/library-tests/ControlFlow/evaluation-order/ConsecutiveTimestamps.expected

@@ -0,0 +1,9 @@
+| test_boolean.py:9:26:9:27 | IntegerLiteral | $@ in $@ has no consecutive successor (expected 2) | test_boolean.py:9:33:9:33 | IntegerLiteral | Timestamp 1 | test_boolean.py:7:1:7:27 | Function test_and_both_sides | test_and_both_sides |
+| test_boolean.py:15:10:15:14 | False | $@ in $@ has no consecutive successor (expected 1) | test_boolean.py:15:20:15:20 | IntegerLiteral | Timestamp 0 | test_boolean.py:13:1:13:30 | Function test_and_short_circuit | test_and_short_circuit |
+| test_boolean.py:21:10:21:13 | True | $@ in $@ has no consecutive successor (expected 1) | test_boolean.py:21:19:21:19 | IntegerLiteral | Timestamp 0 | test_boolean.py:19:1:19:29 | Function test_or_short_circuit | test_or_short_circuit |
+| test_boolean.py:27:26:27:27 | IntegerLiteral | $@ in $@ has no consecutive successor (expected 2) | test_boolean.py:27:33:27:33 | IntegerLiteral | Timestamp 1 | test_boolean.py:25:1:25:26 | Function test_or_both_sides | test_or_both_sides |
+| test_boolean.py:40:45:40:45 | IntegerLiteral | $@ in $@ has no consecutive successor (expected 3) | test_boolean.py:40:51:40:51 | IntegerLiteral | Timestamp 2 | test_boolean.py:38:1:38:24 | Function test_chained_and | test_chained_and |
+| test_boolean.py:46:44:46:45 | IntegerLiteral | $@ in $@ has no consecutive successor (expected 3) | test_boolean.py:46:51:46:51 | IntegerLiteral | Timestamp 2 | test_boolean.py:44:1:44:23 | Function test_chained_or | test_chained_or |
+| test_boolean.py:52:11:52:47 | BoolExpr | $@ in $@ has no consecutive successor (expected 3) | test_boolean.py:52:63:52:63 | IntegerLiteral | Timestamp 2 | test_boolean.py:50:1:50:25 | Function test_mixed_and_or | test_mixed_and_or |
+| test_boolean.py:52:27:52:31 | False | $@ in $@ has no consecutive successor (expected 2) | test_boolean.py:52:37:52:37 | IntegerLiteral | Timestamp 1 | test_boolean.py:50:1:50:25 | Function test_mixed_and_or | test_mixed_and_or |
+| test_boolean.py:52:78:52:79 | IntegerLiteral | $@ in $@ has no consecutive successor (expected 4) | test_boolean.py:52:85:52:85 | IntegerLiteral | Timestamp 3 | test_boolean.py:50:1:50:25 | Function test_mixed_and_or | test_mixed_and_or |

python/ql/test/library-tests/ControlFlow/evaluation-order/ConsecutiveTimestamps.ql

@@ -0,0 +1,25 @@
+/**
+ * Checks that consecutive annotated nodes have consecutive timestamps:
+ * for each annotation with timestamp `a`, some CFG node for that annotation
+ * must have a next annotation containing `a + 1`.
+ *
+ * Handles CFG splitting (e.g., finally blocks duplicated for normal/exceptional
+ * flow) by checking that at least one split has the required successor.
+ *
+ * Only applies to functions where all annotations are in the function's
+ * own scope (excludes tests with generators, async, comprehensions, or
+ * lambdas that have annotations in nested scopes).
+ */
+
+import TimerUtils
+import OldCfgImpl
+
+private module Utils = EvalOrderCfgUtils<OldCfg>;
+
+private import Utils
+private import Utils::CfgTests
+
+from TimerAnnotation ann, int a
+where consecutiveTimestamps(ann, a)
+select ann, "$@ in $@ has no consecutive successor (expected " + (a + 1) + ")",
+  ann.getTimestampExpr(a), "Timestamp " + a, ann.getTestFunction(), ann.getTestFunction().getName()