Shared: Make sure getMadRepresentation is unique

[hvitved]

No description provided.

[Copilot]

Pull Request Overview

This PR ensures that getMadRepresentation produces unique outputs by appending a delimiter and updates the Rust core model mappings to use a consistent argument identifier case.

• Introduce getUniqueMadRepresentation to append a trailing slash for uniqueness
• Replace direct calls to getMadRepresentation in the summary stack builder with the unique version
• Normalize "Self" to "self" in iterator entries of lang-core.model.yml

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
shared/dataflow/codeql/dataflow/internal/FlowSummaryImpl.qll	Added getUniqueMadRepresentation and updated summary stack composition logic
rust/ql/lib/codeql/rust/frameworks/stdlib/lang-core.model.yml	Changed iterator argument identifier from Self to self

Comments suppressed due to low confidence (3)

shared/dataflow/codeql/dataflow/internal/FlowSummaryImpl.qll:690

• There are no tests covering the new getUniqueMadRepresentation logic; consider adding unit tests to validate its behavior and ensure uniqueness is enforced correctly.

private string getUniqueMadRepresentation(SummaryComponent c) {

rust/ql/lib/codeql/rust/frameworks/stdlib/lang-core.model.yml:7

• Ensure the lowercase self identifier matches the case sensitivity expected in all model entries; consider reviewing other mappings for consistency.

- ["lang:core", "<[_]>::iter", "Argument[self].Element", "ReturnValue.Element", "value", "manual"]

shared/dataflow/codeql/dataflow/internal/FlowSummaryImpl.qll:691

• Appending a static / at the end may introduce unexpected trailing delimiters; consider trimming or choosing a clearer delimiter strategy to avoid formatting issues.

result = strictconcat(string s | s = c.getMadRepresentation() | s, "/")

[Copilot]

Add a doc comment explaining the purpose of getUniqueMadRepresentation and why it appends a trailing / delimiter to ensure uniqueness.

Suggested change

	pragma[nomagic]
	pragma[nomagic]
	/**
	* Generates a unique string representation of the given `SummaryComponent`.
	*
	* This representation is used in MaD (Model and Dataflow) models to uniquely
	* identify components. A trailing `/` is appended to ensure that the resulting
	* string is distinct from other potential string formats and avoids collisions
	* when concatenated with other representations.
	*
	* @param c The `SummaryComponent` to generate a representation for.
	* @return A unique string representation of the component.
	*/

[geoffw0]

I have to admit I would really appreciate a description of what's going on here. What would a collision look like?

[geoffw0]

Approving to get things moving, but I would appreciate more understanding of this issue.

[geoffw0]

👍

[geoffw0]

I have to admit I would really appreciate a description of what's going on here. What would a collision look like?

[hvitved]

I have to admit I would really appreciate a description of what's going on here. What would a collision look like?

@geoffw0 : For Rust, some struct fields have non-unique getCanonicalPaths right now. We may or may not be able to fix that, in all cases it is a good idea to safe-guard against it (for all languages).