Skip to content

Experiment: restore captured-jump selectivity with shared SSA #22402

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Draft
yoff wants to merge 2 commits into
base: yoff/python-shared-cfg-dataflow-flip
Choose a base branch
from
+22 −2
Draft

Experiment: restore captured-jump selectivity with shared SSA #22402

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
439edf6
Python: test captured jump reassignment trade-off
yoff Aug 21, 2026
33133d6
Python: gate captured jumps on SSA writes
yoff Aug 21, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
6 changes: 4 additions & 2 deletions python/ql/lib/semmle/python/dataflow/new/internal/TypeTrackingImpl.qll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -324,10 +324,12 @@ module TypeTrackingInput implements Shared::TypeTrackingInput<Location> {
// nodeFrom is `expr`
// nodeTo is entry node for `f`
exists(
SsaImpl::ScopeEntryDefinition e, SsaImpl::SsaSourceVariable var, Cfg::DefinitionNode def
SsaImpl::ScopeEntryDefinition e, SsaImpl::SsaSourceVariable var,
SsaImpl::EssaNodeDefinition write, Cfg::DefinitionNode def
|
e.getSourceVariable() = var and
def.getNode() = var.getVariable().getAStore()
write.getSourceVariable() = var and
write.getDefiningNode() = def
|
nodeTo.(DataFlowPublic::ScopeEntryDefinitionNode).getDefinition() = e and
nodeFrom.asCfgNode() = def and
Expand Down
18 changes: 18 additions & 0 deletions python/ql/test/library-tests/dataflow/typetracking/test.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -78,6 +78,24 @@ def inner():
print(also_x) # $ tracked


# ------------------------------------------------------------------------------
# Captured variable reassignment
# ------------------------------------------------------------------------------

def captured_reassignment_tradeoff():
value = tracked # $ tracked

def read_value():
return value # $ MISSING: tracked

before_reassignment = read_value() # $ MISSING: tracked
value = "safe"
safe_sibling = read_value()

before_reassignment # $ MISSING: tracked
safe_sibling


# ------------------------------------------------------------------------------
# Function decorator
# ------------------------------------------------------------------------------
Expand Down