wip5

Author: hvitved

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

@@ -2773,29 +2773,21 @@ module Make1<LocationSig Location, InputSig1<Location> Input1> {
       private module InvocationMatchingInput implements MatchingWithEnvironmentInputSig {
         import InvocationTypeQualifierMatchingInput
 
-        private newtype TDeclarationPosition =
-          TParameterPosition(int i) { exists(any(Parameterizable p).getParameter(i)) } or
-          TReturnPosition()
-
-        class DeclarationPosition extends TDeclarationPosition {
-          int asParameter() { this = TParameterPosition(result) }
-
-          predicate isReturn() { this = TReturnPosition() }
-
-          string toString() {
-            result = "parameter " + this.asParameter()
-            or
-            this.isReturn() and
-            result = "return"
-          }
-        }
+        class DeclarationPosition = int;
 
         class AccessPosition = DeclarationPosition;
 
+        bindingset[apos]
+        bindingset[dpos]
         predicate accessDeclarationPositionMatch(AccessPosition apos, DeclarationPosition dpos) {
           apos = dpos
         }
 
+        /** Gets the position used to represent the return type of a callable/type of a call. */
+        additional int getReturnPosition() {
+          result = min(int i | exists(any(Parameterizable p).getParameter(i)) | i) - 1
+        }
+
         class Declaration extends ParameterizableFinal {
           TypeParameter getTypeParameter(int pos) {
             // include type parameters that are matched via a type qualifier
@@ -2811,9 +2803,9 @@ module Make1<LocationSig Location, InputSig1<Location> Input1> {
           }
 
           Type getDeclaredType(DeclarationPosition dpos, TypePath path) {
-            result = this.getParameter(dpos.asParameter()).getType().getTypeAt(path)
+            result = this.getParameter(dpos).getType().getTypeAt(path)
             or
-            dpos.isReturn() and
+            dpos = getReturnPosition() and
             result = getParameterizableReturnType(this, path)
           }
         }
@@ -2843,12 +2835,12 @@ module Make1<LocationSig Location, InputSig1<Location> Input1> {
           pragma[nomagic]
           private Type getInferredReturnType(AccessPosition apos, TypePath path) {
             result = inferInvocationTypeContextual(this, path) and
-            apos.isReturn()
+            apos = getReturnPosition()
           }
 
           bindingset[e]
           Type getInferredType(AccessEnvironment e, AccessPosition apos, TypePath path) {
-            result = inferInvocationArgumentType(this, e, apos.asParameter(), path)
+            result = inferInvocationArgumentType(this, e, apos, path)
             or
             result = this.getInferredReturnType(apos, path) and
             exists(e)
@@ -2867,10 +2859,9 @@ module Make1<LocationSig Location, InputSig1<Location> Input1> {
        */
       pragma[nomagic]
       Type inferInvocationTypeDefault(Invocation invocation, ResolutionContext ctx, TypePath path) {
-        exists(InvocationMatchingInput::AccessPosition apos |
-          result = InvocationMatching::inferAccessType(invocation, ctx, apos, path) and
-          apos.isReturn()
-        )
+        result =
+          InvocationMatching::inferAccessType(invocation, ctx,
+            InvocationMatchingInput::getReturnPosition(), path)
       }
 
       /**
@@ -2881,12 +2872,9 @@ module Make1<LocationSig Location, InputSig1<Location> Input1> {
       Type inferInvocationArgumentTypeContextualDefault(
         Invocation invocation, ResolutionContext ctx, int pos, Expr arg, TypePath path
       ) {
-        exists(InvocationMatchingInput::AccessPosition apos |
-          pos = apos.asParameter() and
-          arg = invocation.getArgument(pos) and
-          result = InvocationMatching::inferAccessType(invocation, ctx, apos, path) and
-          ContextualTyping::hasUnknownType(arg)
-        )
+        arg = invocation.getArgument(pos) and
+        result = InvocationMatching::inferAccessType(invocation, ctx, pos, path) and
+        ContextualTyping::hasUnknownType(arg)
       }
 
       /**