wip

Author: hvitved

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

@@ -33,5 +33,11 @@ module Impl {
         result = "impl " + trait + this.getSelfTy().toAbbreviatedString() + " { ... }"
       )
     }
+
+    /**
+     * Holds if this is an inherent `impl` block, that is, one that does not implement a trait.
+     */
+    pragma[nomagic]
+    predicate isInherent() { not this.hasTrait() }
   }
 }

rust/ql/lib/codeql/rust/internal/typeinference/TypeInference.qll

@@ -1521,23 +1521,14 @@ private module AssocFunctionResolution {
 
   private module AssocFunctionTraitIsVisible = TraitIsVisible<assocFunctionCallTraitCandidate/2>;
 
-  pragma[nomagic]
-  predicate callVisibleTraitCandidate(AssocFunctionCall afc, Trait trait) {
-    AssocFunctionTraitIsVisible::traitIsVisible(afc, trait)
-    or
-    // if the call has a trait qualifier then that trait must be visible
-    trait = afc.getTrait()
-  }
+  predicate callVisibleTraitCandidate = AssocFunctionTraitIsVisible::traitIsVisible/2;
 
   bindingset[afc, impl]
   pragma[inline_late]
   private predicate callVisibleImplTraitCandidate(AssocFunctionCall afc, ImplItemNode impl) {
     callVisibleTraitCandidate(afc, impl.resolveTraitTy())
   }
 
-  pragma[nomagic]
-  private predicate implHasNoTrait(Impl i) { not i.hasTrait() }
-
   /**
    * Holds if call `afc` may target function `f` in `i` with type `selfType` at
    * `selfPos`.
@@ -1560,11 +1551,18 @@ private module AssocFunctionResolution {
       assocFunctionInfoNonBlanketLike(f, name, arity, selfPos, selfPosAdj, i, selfType,
         strippedTypePath, strippedType, implType, isMethod)
     |
-      implHasNoTrait(i)
+      i.(Impl).isInherent() and
+      not afc.hasTrait()
       or
       callVisibleImplTraitCandidate(afc, i)
       or
       callVisibleTraitCandidate(afc, i)
+      or
+      exists(Trait trait | trait = afc.getTrait() |
+        i.(ImplItemNode).resolveTraitTy() = trait
+        or
+        i = trait
+      )
     )
   }
 
@@ -1588,8 +1586,11 @@ private module AssocFunctionResolution {
     exists(string name, int arity, boolean isMethod |
       afc.hasNameAndArity(name, arity, _, isMethod) and
       assocFunctionSelfInfoBlanketLike(f, name, arity, selfPos, selfPosAdj, impl, _, self,
-        blanketPath, blanketTypeParam, isMethod) and
+        blanketPath, blanketTypeParam, isMethod)
+    |
       callVisibleImplTraitCandidate(afc, impl)
+      or
+      impl.resolveTraitTy() = afc.getTrait()
     )
   }
 
@@ -1647,17 +1648,15 @@ private module AssocFunctionResolution {
      */
     pragma[nomagic]
     private predicate isRelevantSelfPos(FunctionPosition selfPos) {
+      not this.hasReceiver() and
       exists(TypePath strippedTypePath, Type strippedType |
-        strippedType = substituteLookupTraits(this.getTypeAt(selfPos, strippedTypePath))
+        strippedType = substituteLookupTraits(this.getTypeAt(selfPos, strippedTypePath)) and
+        strippedType != TNeverType() and
+        strippedType != TUnknownType()
       |
-        selfPos.isSelfOrTypeQualifier()
+        nonBlanketLikeCandidate(this, _, _, selfPos, _, _, strippedTypePath, strippedType)
         or
-        not this.hasReceiver() and
-        (
-          blanketLikeCandidate(this, _, _, selfPos, _, _, _, _)
-          or
-          nonBlanketLikeCandidate(this, _, _, selfPos, _, _, strippedTypePath, strippedType)
-        )
+        blanketLikeCandidate(this, _, _, selfPos, _, _, strippedTypePath, _)
       )
     }
 
@@ -1668,7 +1667,11 @@ private module AssocFunctionResolution {
     Type getSelfTypeAtNoBorrow(FunctionPosition selfPos, DerefChain derefChain, TypePath path) {
       result = this.getTypeAt(selfPos, path) and
       derefChain.isEmpty() and
-      this.isRelevantSelfPos(selfPos)
+      (
+        selfPos.isSelfOrTypeQualifier()
+        or
+        this.isRelevantSelfPos(selfPos)
+      )
       or
       exists(DerefImplItemNode impl, DerefChain suffix |
         result =
@@ -2314,7 +2317,7 @@ private module AssocFunctionResolution {
         forall(Impl i |
           assocFunctionInfoNonBlanketLike(_, name, arity, _, selfPosAdj, i, _, strippedTypePath,
             strippedType, _, _) and
-          not i.hasTrait()
+          i.isInherent()
         |
           this.hasIncompatibleInherentTarget(i)
         )
@@ -2548,7 +2551,7 @@ private module AssocFunctionResolution {
       AssocFunctionCallCand afcc, TypeAbstraction abs, AssocFunctionType constraint
     ) {
       ArgIsInstantiationOfSelfParamInput::potentialInstantiationOf0(afcc, abs, constraint) and
-      abs = any(Impl i | not i.hasTrait()) and
+      abs.(Impl).isInherent() and
       // todo: comment
       exists(FunctionPosition selfPosAdj | afcc = MkAssocFunctionCallCand(_, _, selfPosAdj, _, _) |
         selfPosAdj.isTypeQualifier() or selfPosAdj.asPosition() = 0