The shared CFG library overrides ControlFlowNode.toString() as 'final'
(shared/controlflow/codeql/controlflow/Cfg.qll:1217), so the legacy
'ControlFlowNode for X' prefix is gone — the new toString returns just
'X' for normal nodes and 'After X' for after-nodes. This produces a
large cosmetic diff in test expected files with no semantic change.
Mass-rebless 78 .expected files whose actual output differs from the
checked-in expected only by this rename. Each file was verified to be
identical after normalising 'ControlFlowNode for ' and 'After ' away
from both sides.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
This commit removes SSA nodes from the data flow graph. Specifically, for a definition and use such as
```python
x = expr
y = x + 2
```
we used to have flow from `expr` to an SSA variable representing x and from that SSA variable to the use of `x` in the definition of `y`. Now we instead have flow from `expr` to the control flow node for `x` at line 1 and from there to the control flow node for `x` at line 2.
Specific changes:
- `EssaNode` from the data flow layer no longer exists.
- Several glue steps between `EssaNode`s and `CfgNode`s have been deleted.
- Entry nodes are now admitted as `CfgNodes` in the data flow layer (they were filtered out before).
- Entry nodes now have a new `toString` taking into account that the module name may be ambigous.
- Some tests have been rewritten to accomodate the changes, but only `python/ql/test/experimental/dataflow/basic/maximalFlowsConfig.qll` should have semantic changes.
- Comments have been updated
- Test output has been updated, but apart from `python/ql/test/experimental/dataflow/basic/maximalFlows.expected` only `python/ql/test/experimental/dataflow/typetracking-summaries/summaries.py` should have a semantic change. This is a bonus fix, probably meaning that something was never connected up correctly.
