Skip to content

Add IndirectUninitializedNode and related helper predicates #21458

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

Merged
jketema merged 12 commits into from
Mar 23, 2026
Merged

Add IndirectUninitializedNode and related helper predicates #21458

Changes from 1 commit
Commits
Show all changes
12 commits
Select commit Hold shift + click to select a range
6c792e6
Expose the indirection index
jeongsoolee09 Mar 11, 2026
8c03136
Revert "Expose the indirection index"
jeongsoolee09 Mar 13, 2026
d3066af
Create `IndirectUninitializedNode` and add a bridge from it to `Local…
jeongsoolee09 Mar 13, 2026
f8a3ce7
Merge branch 'main' into jeongsoolee09/add-getIndirectionIndex
jeongsoolee09 Mar 14, 2026
3f9ad14
Factor out common code into an abstract private class
jeongsoolee09 Mar 16, 2026
d191d09
Apply suggestions from code review
jeongsoolee09 Mar 19, 2026
dc291ff
Address code review
jeongsoolee09 Mar 19, 2026
356905b
Merge branch 'jeongsoolee09/add-getIndirectionIndex' of github.com:gi…
jeongsoolee09 Mar 19, 2026
d2fcced
Add a `feature` change note
jeongsoolee09 Mar 20, 2026
d4fef1c
Merge branch 'main' into jeongsoolee09/add-getIndirectionIndex
jeongsoolee09 Mar 20, 2026
6ae32f2
Merge branch 'main' into jeongsoolee09/add-getIndirectionIndex
jeongsoolee09 Mar 22, 2026
ee00b98
Update cpp/ql/lib/change-notes/2026-03-20-add-indirect-uninitialized-…
jketema Mar 23, 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: 5 additions & 1 deletion cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowNodes.qll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -767,10 +767,11 @@ module Public {
*/
class UninitializedNode extends Node {
LocalVariable v;
int indirectionIndex;
Copy link

Copilot AI Mar 11, 2026

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

The class-level doc comment for UninitializedNode now understates the behavior: the implementation no longer represents only indirection level 0. Please update the doc comment to mention that the node can represent different indirection indices (and briefly what 0/1/... mean) so query authors don’t misinterpret it.

This issue also appears on line 784 of the same file.

Copilot uses AI. Check for mistakes.
Copy link
Copy Markdown
Contributor

@MathiasVP MathiasVP Mar 12, 2026 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Copilot is right here. The changes here are actually a semantically breaking change (which would need a full deprecation cycle).

Instead of doing what you have here, I suggest you do what I hinted at on Slack:

  1. Keep the UninitializedNode as it currently is on main
  2. Create a new class IndirectUninitializedNode which basically the the charpred you have here (and indirectionIndex > 1 to avoid overlap with UninitializedNode)
  3. Add a new predicate LocalVariable asIndirectUninitializedNode(int indirectionIndex) on DataFlow::Node and an convenience predicate with 0 parameters LocalVariable asIndirectUninitializedNode() implemented as result = this.asIndirectUninitializedNode(_).

This avoids a breaking change to the UninitializedNode class and the asUninitializedNode predicate.

Copy link
Copy Markdown
Contributor Author

@jeongsoolee09 jeongsoolee09 Mar 13, 2026

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Addressed in d3066af.


UninitializedNode() {
exists(SsaImpl::Definition def, SsaImpl::SourceVariable sv |
def.getIndirectionIndex() = 0 and
def.getIndirectionIndex() = indirectionIndex and
def.getValue().asInstruction() instanceof UninitializedInstruction and
SsaImpl::defToNode(this, def, sv) and
v = sv.getBaseVariable().(SsaImpl::BaseIRVariable).getIRVariable().getAst()
Expand All @@ -779,6 +780,9 @@ module Public {

/** Gets the uninitialized local variable corresponding to this node. */
LocalVariable getLocalVariable() { result = v }

/** Gets the level of indirection to get to this node. */
Comment thread
jeongsoolee09 marked this conversation as resolved.
Outdated
int getIndirectionIndex() { result = indirectionIndex }
}

/**
Expand Down
Loading