Rust: Fix trait visibility on Self

Author: paldepind

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

@@ -2020,8 +2020,24 @@ private ItemNode resolvePathCand(PathExt path) {
 
 /** Get a trait that should be visible when `path` resolves to `node`, if any. */
 private Trait getResolvePathTraitUsed(PathExt path, AssocItemNode node) {
-  exists(TypeItemNode type, ImplItemNodeImpl impl |
-    node = resolvePathCandQualified(_, type, path, _) and
+  // exists(TypeItemNode type, ImplItemNodeImpl impl |
+  //   node = resolvePathCandQualified(_, type, path, _) and
+  //   typeImplEdge(type, impl, _, node) and
+  //   result = impl.resolveTraitTyCand()
+  // )
+  // exists(ItemNode qq |
+  //   node = resolvePathCandQualified(_, qq, path, _) and
+  //   not qq instanceof Trait and
+  //   not qq instanceof TypeParam and
+  //   (
+  //     result.(TraitItemNode).getAnAssocItem() = node
+  //     or
+  //     result = any(ImplItemNodeImpl impl | impl.getAnAssocItem() = node).resolveTraitTyCand()
+  //   )
+  // )
+  exists(TypeItemNode type, ItemNode qual, ImplItemNodeImpl impl |
+    node = resolvePathCandQualified(_, qual, path, _) and
+    type = [qual, qual.(ImplItemNodeImpl).resolveSelfTyCand()] and
     typeImplEdge(type, impl, _, node) and
     result = impl.resolveTraitTyCand()
   )
@@ -2250,13 +2266,48 @@ private module Debug {
   Locatable getRelevantLocatable() {
     exists(string filepath, int startline, int startcolumn, int endline, int endcolumn |
       result.getLocation().hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn) and
-      // filepath.matches("%/lex.rs") and
-      // startline = [156 .. 163]
-      filepath.matches("%/algorithm/mod.rs") and
-      startline = [300 .. 303]
+      filepath.matches("%/array.rs") and
+      startline = [272 .. 291]
+      // filepath.matches("%/main.rs") and
+      // startline = [612]
     )
   }
 
+  private Trait debugGetResolvePathTraitUsed(PathExt path, AssocItemNode node) {
+    path.toString() = "Self::empty" and
+    path = getRelevantLocatable() and
+    result = getResolvePathTraitUsed(path, node)
+  }
+
+  predicate resolveSelf(
+    Path p, ItemNode s, ImplOrTraitItemNode fr1, ItemNode cand, ImplOrTraitItemNode fr2, ItemNode it
+  ) {
+    p = getRelevantLocatable() and
+    p.toString() = "Self::empty" and
+    cand = resolvePathCand(p) and
+    fr1.getAnAssocItem() = cand and
+    it = resolvePathIgnoreVariableShadowing(p) and
+    fr2.getAnAssocItem() = it and
+    s = resolvePathCand(p.getQualifier())
+  }
+
+  predicate path(
+    Path p, Function f, ImplItemNode i, ItemNode ty, ImplOrTraitItemNode frm, ItemNode succ
+  ) {
+    p = getRelevantLocatable() and
+    p.toString() = "Self::empty" and
+    p.getParentNode*() = f and
+    p.getParentNode*() = i and
+    // ty = i.getSelfTy() and
+    i.resolveSelfTy() = ty and
+    frm.getAnAssocItem() = succ and
+    ty.getASuccessor("empty") = succ
+  }
+
+  // predicate bbbb(Path p, Impl i, string name) {
+  //   path(p, _, i, _) and
+  //   relevantSelfFunctionName(i, name)
+  // }
   predicate debugUnqualifiedPathLookup(
     PathExt p, string name, Namespace ns, ItemNode ancestor, string path
   ) {