Rust: Extend jump-to-def query with method calls

[hvitved]

Also fixes jump-to-def for paths so only the path segment is used, for example in M1::M2 only the M2 segment jumps to the M2 module, not the entire M1::M2 path).

[Copilot]

Pull Request Overview

This PR enhances the jump-to-definition query in the Rust CodeQL library to handle method calls and to restrict path-based definitions to individual segments (e.g., only M2 in M1::M2).

• Introduces a new MethodUse class to resolve method call identifiers
• Refines PathUse to work on PathSegment nodes and include call disambiguation
• Updates test suite to verify method and segmented-path resolutions

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
rust/ql/test/library-tests/definitions/main.rs	Adds a nested module with S::method and corresponding use in main for testing method-resolution
rust/ql/test/library-tests/definitions/Definitions.expected	Updates expected definitions output to include new path-segment and method entries
rust/ql/lib/codeql/rust/internal/Definitions.qll	Extends PathUse to PathSegment, adds call-aware logic, and introduces MethodUse for method call resolution

Comments suppressed due to low confidence (2)

rust/ql/lib/codeql/rust/internal/Definitions.qll:143

• [nitpick] The method name getCall() is somewhat vague; consider renaming it to getAssociatedCallExpr() or similar to clarify its purpose.

  private CallExpr getCall() { result.getFunction().(PathExpr).getPath() = path }

rust/ql/lib/codeql/rust/internal/Definitions.qll:138

• [nitpick] Add a brief comment above this class explaining that it handles individual path segments (including calls) for jump-to-definition resolutions, to aid future readers.

private class PathUse extends Use instanceof PathSegment {

[Copilot]

Consider caching the result of getCall() in a local variable or predicate to avoid traversing the AST twice in getDefinition, improving performance.

Suggested change

	// Our call resolution logic may disambiguate some calls, so only use those
	result.asItemNode() = this.getCall().getStaticTarget()
	or
	not exists(this.getCall()) and
	// Cache the result of getCall() to avoid traversing the AST twice
	CallExpr cachedCall = this.getCall();
	// Our call resolution logic may disambiguate some calls, so only use those
	result.asItemNode() = cachedCall.getStaticTarget()
	or
	not exists(cachedCall) and