Rust: Handle pub use reexports in path resolution

Author: hvitved

rust/ql/lib/codeql/rust/internal/PathResolution.qll

@@ -460,7 +460,7 @@ private class UseItemNode extends ItemNode instanceof Use {
 
   override Namespace getNamespace() { none() }
 
-  override Visibility getVisibility() { none() }
+  override Visibility getVisibility() { result = Use.super.getVisibility() }
 
   override TypeParam getTypeParam(int i) { none() }
 }
@@ -588,9 +588,15 @@ private predicate fileImport(Module m, SourceFile f) {
  */
 private predicate fileImportEdge(Module mod, string name, ItemNode item) {
   item.isPublic() and
-  exists(SourceFile f |
-    fileImport(mod, f) and
+  exists(SourceFile f | fileImport(mod, f) |
     sourceFileEdge(f, name, item)
+    or
+    // `pub use` reexport
+    exists(UseItemNode use |
+      sourceFileEdge(f, _, use) and
+      use.isPublic() and
+      useImportEdge(use, name, item)
+    )
   )
 }
 

rust/ql/test/library-tests/path-resolution/main.rs

@@ -495,5 +495,5 @@ fn main() {
     m15::f(); // $ item=I75
     m16::f(); // $ item=I83
     m17::f(); // $ item=I99
-    nested6::f(); // $ MISSING: item=I116
+    nested6::f(); // $ item=I116
 }

rust/ql/test/library-tests/path-resolution/path-resolution.expected

@@ -251,6 +251,8 @@ resolvePath
 | main.rs:496:5:496:10 | ...::f | main.rs:417:5:441:5 | fn f |
 | main.rs:497:5:497:7 | m17 | main.rs:444:1:474:1 | mod m17 |
 | main.rs:497:5:497:10 | ...::f | main.rs:468:5:473:5 | fn f |
+| main.rs:498:5:498:11 | nested6 | my2/nested2.rs:14:5:18:5 | mod nested6 |
+| main.rs:498:5:498:14 | ...::f | my2/nested2.rs:15:9:17:9 | fn f |
 | my2/mod.rs:5:5:5:11 | nested2 | my2/mod.rs:1:1:1:16 | mod nested2 |
 | my2/mod.rs:5:5:5:20 | ...::nested3 | my2/nested2.rs:1:1:11:1 | mod nested3 |
 | my2/mod.rs:5:5:5:29 | ...::nested4 | my2/nested2.rs:2:5:10:5 | mod nested4 |