wip5

Author: hvitved

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

@@ -480,18 +480,18 @@ private module Input3 implements InputSig3 {
       )
     or
     exists(CallExprImpl::DynamicCallExpr dce, TupleType tt, int i |
+      n1 = dce.getSyntacticPositionalArgument(i) and
       n2 = dce.getArgList() and
       tt.getArity() = dce.getNumberOfSyntacticArguments() and
-      n1 = dce.getSyntacticPositionalArgument(i) and
-      path2 = TypePath::singleton(tt.getPositionalTypeParameter(i)) and
-      path1.isEmpty()
+      path1.isEmpty() and
+      path2 = TypePath::singleton(tt.getPositionalTypeParameter(i))
     )
     or
     exists(ClosureExpr ce, int index |
-      n2 = ce and
       n1 = ce.getParam(index).getPat() and
-      path2 = closureParameterPath(ce.getNumberOfParams(), index) and
-      path1.isEmpty()
+      n2 = ce and
+      path1.isEmpty() and
+      path2 = closureParameterPath(ce.getNumberOfParams(), index)
     )
   }
 

shared/typeinference/codeql/typeinference/internal/TypeInference.qll

@@ -1361,6 +1361,14 @@ module Make1<LocationSig Location, InputSig1<Location> Input1> {
     module MatchingWithEnvironment<MatchingWithEnvironmentInputSig Input> {
       private import Input
 
+      pragma[nomagic]
+      private TypeParameter getDeclTypeParameter(Declaration decl, TypeArgumentPosition tapos) {
+        exists(TypeParameterPosition tppos |
+          result = decl.getTypeParameter(tppos) and
+          typeArgumentParameterPositionMatch(tapos, tppos)
+        )
+      }
+
       /**
        * Gets the type of the type argument at `path` in `a` that corresponds to
        * the type parameter `tp` in `target`, if any.
@@ -1372,10 +1380,9 @@ module Make1<LocationSig Location, InputSig1<Location> Input1> {
       bindingset[a, target]
       pragma[inline_late]
       private Type getTypeArgument(Access a, Declaration target, TypeParameter tp, TypePath path) {
-        exists(TypeArgumentPosition tapos, TypeParameterPosition tppos |
+        exists(TypeArgumentPosition tapos |
           result = a.getTypeArgument(tapos, path) and
-          tp = target.getTypeParameter(tppos) and
-          typeArgumentParameterPositionMatch(tapos, tppos) and
+          tp = getDeclTypeParameter(target, tapos) and
           not result instanceof UnknownType //and path.isEmpty())
         )
       }
@@ -2403,6 +2410,7 @@ module Make1<LocationSig Location, InputSig1<Location> Input1> {
         private predicate infersCertainTypeAt(AstNode n, TypePath prefix, TypeParameter tp) {
           exists(TypePath path |
             hasInferredCertainType(n, path) and
+            not path.isEmpty() and // implied by `isSnoc` below, but improves performance slightly
             path.isSnoc(prefix, tp)
           )
         }
@@ -2521,26 +2529,26 @@ module Make1<LocationSig Location, InputSig1<Location> Input1> {
           not Certain::certainTypeConflict(n, prefix, path, result)
         )
         or
-        hasUnknownCertainTypeAt(n, path) and
-        result instanceof UnknownType
-        or
-        infersTypeAt(n, path, result.getATypeParameter())
-      }
-
-      private predicate hasUnknownCertainTypeAt(AstNode n, TypePath path) {
+        // If `n` has an explicitly unknown type at `prefix` and at the same time a certain
+        // type at `prefix.suffix`, then extend the unknown type information to any path
+        // extending `prefix.suffix` where there is no certain type information
         exists(TypePath prefix, TypePath suffix, Type certain, TypeParameter tp |
           inferType0(n, prefix) instanceof UnknownType and
           certain = inferTypeCertain(n, prefix.appendInverse(suffix)) and
           tp = certain.getATypeParameter() and
           path = prefix.append(suffix).append(TypePath::singleton(tp)) and
-          not exists(inferTypeCertain(n, path))
+          not exists(inferTypeCertain(n, path)) and
+          result instanceof UnknownType
         )
+        or
+        infersTypeAt(n, path, result.getATypeParameter())
       }
 
       pragma[nomagic]
       private predicate infersTypeAt(AstNode n, TypePath prefix, TypeParameter tp) {
         exists(TypePath path |
           exists(inferType(n, path)) and
+          not path.isEmpty() and // implied by `isSnoc` below, but improves performance slightly
           path.isSnoc(prefix, tp)
         )
       }