make function that substitutes explicit type arguments

uber · Nov 13, 2024 · 3f3ebf2 · 3f3ebf2
1 parent cc45e43
commit 3f3ebf2
Showing 1 changed file with 17 additions and 33 deletions.
diff --git a/nullaway/src/main/java/com/uber/nullaway/generics/GenericsChecks.java b/nullaway/src/main/java/com/uber/nullaway/generics/GenericsChecks.java
@@ -628,15 +628,8 @@ public static void compareGenericTypeParameterNullabilityForCall(
     }
     // Handle generic methods
     if (tree instanceof MethodInvocationTree && methodSymbol.type instanceof Type.ForAll) {
-      MethodInvocationTree methodInvocationTree = (MethodInvocationTree) tree;
-
-      List<? extends Tree> typeArgumentTrees = methodInvocationTree.getTypeArguments();
-      com.sun.tools.javac.util.List<Type> explicitTypeArgs = convertTreesToTypes(typeArgumentTrees);
-
-      Type.ForAll forAllType = (Type.ForAll) methodSymbol.type;
-      Type.MethodType underlyingMethodType = (Type.MethodType) forAllType.qtype;
       invokedMethodType =
-          state.getTypes().subst(underlyingMethodType, forAllType.tvars, explicitTypeArgs);
+          substituteGenericTypeArgsToExplicit((MethodInvocationTree) tree, methodSymbol, state);
     }
     List<Type> formalParamTypes = invokedMethodType.getParameterTypes();
     int n = formalParamTypes.size();
@@ -825,19 +818,9 @@ public static Nullness getGenericReturnNullnessAtInvocation(
       Config config) {
     // If generic method invocation
     if (!invokedMethodSymbol.getTypeParameters().isEmpty()) {
-      List<? extends Tree> typeArgumentTrees = tree.getTypeArguments();
-      com.sun.tools.javac.util.List<Type> explicitTypeArgs =
-          convertTreesToTypes(typeArgumentTrees); // Convert to Type objects
-      Type.ForAll forAllType = (Type.ForAll) invokedMethodSymbol.type;
-      // Extract the underlying MethodType (the actual signature)
-      Type.MethodType methodTypeInsideForAll = (Type.MethodType) forAllType.asMethodType();
       // Substitute type arguments inside the return type
-      // NOTE: if the return type it not a type variable of the method itself, or if
-      // explicitTypeArgs is empty, this is a noop.
       Type substitutedReturnType =
-          state
-              .getTypes()
-              .subst(methodTypeInsideForAll.restype, forAllType.tvars, explicitTypeArgs);
+          substituteGenericTypeArgsToExplicit(tree, invokedMethodSymbol, state).getReturnType();
       // If this condition evaluates to false, we fall through to the subsequent logic, to handle
       // type variables declared on the enclosing class
       if (substitutedReturnType != null
@@ -871,6 +854,20 @@ private static com.sun.tools.javac.util.List<Type> convertTreesToTypes(
     return com.sun.tools.javac.util.List.from(types);
   }
 
+  private static Type substituteGenericTypeArgsToExplicit(
+      MethodInvocationTree methodInvocationTreetree,
+      Symbol.MethodSymbol methodSymbol,
+      VisitorState state) {
+    MethodInvocationTree methodInvocationTree = (MethodInvocationTree) methodInvocationTreetree;
+
+    List<? extends Tree> typeArgumentTrees = methodInvocationTree.getTypeArguments();
+    com.sun.tools.javac.util.List<Type> explicitTypeArgs = convertTreesToTypes(typeArgumentTrees);
+
+    Type.ForAll forAllType = (Type.ForAll) methodSymbol.type;
+    Type.MethodType underlyingMethodType = (Type.MethodType) forAllType.qtype;
+    return state.getTypes().subst(underlyingMethodType, forAllType.tvars, explicitTypeArgs);
+  }
+
   /**
    * Computes the nullness of a formal parameter of a generic method at an invocation, in the
    * context of the declared type of its receiver argument. If the formal parameter's type is a type
@@ -913,23 +910,10 @@ public static Nullness getGenericParameterNullnessAtInvocation(
       Config config) {
     // If generic method invocation
     if (!invokedMethodSymbol.getTypeParameters().isEmpty()) {
-      List<? extends Tree> typeArgumentTrees = tree.getTypeArguments();
-      com.sun.tools.javac.util.List<Type> explicitTypeArgs =
-          convertTreesToTypes(typeArgumentTrees); // Convert to Type objects
-
-      Type.ForAll forAllType = (Type.ForAll) invokedMethodSymbol.type;
-      // Extract the underlying MethodType (the actual signature)
-      Type.MethodType methodTypeInsideForAll = (Type.MethodType) forAllType.qtype;
       // Substitute the argument types within the MethodType
       // NOTE: if explicitTypeArgs is empty, this is a noop
       List<Type> substitutedParamTypes =
-          state
-              .getTypes()
-              .subst(
-                  methodTypeInsideForAll.argtypes,
-                  forAllType.tvars, // The type variables from the ForAll
-                  explicitTypeArgs // The actual type arguments from the method invocation
-                  );
+          substituteGenericTypeArgsToExplicit(tree, invokedMethodSymbol, state).getParameterTypes();
       // If this condition evaluates to false, we fall through to the subsequent logic, to handle
       // type variables declared on the enclosing class
       if (substitutedParamTypes != null