Rust: Take dependency renaming into account when extracting the crate graph

rust/extractor/src/crate_graph.rs

@@ -88,6 +88,17 @@ pub fn extract_crate_graph(trap_provider: &trap::TrapFileProvider, db: &RootData
             let file_label = trap.emit_file(root_module_file);
             trap.emit_file_only_location(file_label, root_module);
 
+            let crate_dependencies: Vec<generated::NamedCrate> = krate
+                .dependencies
+                .iter()
+                .flat_map(|x| crate_id_map.get(&x.crate_id).map(|y| (&x.name, y)))
+                .map(|(name, (module, hash))| generated::NamedCrate {
+                    id: trap::TrapId::Star,
+                    name: name.to_string(),
+                    crate_: trap.label(format!("{}:{hash}", module.display()).into()),
+                })
+                .collect();
+
             let element = generated::Crate {
                 id: trap::TrapId::Key(format!("{}:{hash}", root_module_file.display())),
                 name: krate
@@ -102,11 +113,9 @@ pub fn extract_crate_graph(trap_provider: &trap::TrapFileProvider, db: &RootData
                     .into_iter()
                     .map(|x| format!("{x}"))
                     .collect(),
-                dependencies: krate
-                    .dependencies
-                    .iter()
-                    .flat_map(|x| crate_id_map.get(&x.crate_id))
-                    .map(|(module, hash)| trap.label(format!("{}:{hash}", module.display()).into()))
+                named_dependencies: crate_dependencies
+                    .into_iter()
+                    .map(|dep| trap.emit(dep))
                     .collect(),
             };
             trap.emit(element);

rust/ql/lib/codeql/rust/elements/internal/CrateImpl.qll

@@ -12,6 +12,7 @@ private import codeql.rust.elements.internal.generated.Crate
  */
 module Impl {
   private import rust
+  private import codeql.rust.elements.internal.NamedCrate
 
   class Crate extends Generated::Crate {
     override string toStringImpl() {
@@ -30,6 +31,33 @@ module Impl {
       i = 4 and result = ")"
     }
 
+    /**
+     * Gets the dependency named `name`, if any.
+     *
+     * `name` may be different from the name of the crate, when the dependency has been
+     * renamed in the `Cargo.toml` file, for example in
+     *
+     * ```yml
+     * [dependencies]
+     * my_serde = {package = "serde", version = "1.0.217"}
+     * ```
+     *
+     * the name of the dependency is `my_serde`, but the name of the crate is `serde`.
+     */
+    pragma[nomagic]
+    Crate getDependency(string name) {
+      exists(NamedCrate c |
+        c = this.getANamedDependency() and
+        result = c.getCrate() and
+        name = c.getName()
+      )
+    }
+
+    /**
+     * Gets any dependency of this crate.
+     */
+    Crate getADependency() { result = this.getDependency(_) }
+
     override Location getLocation() { result = this.getModule().getLocation() }
   }
 }