Model Class.cast (#731)

also call `getOptLibraryModels` only once
uber · Feb 6, 2023 · de74310 · de74310
1 parent ed0ef72
commit de74310
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Showing 2 changed files with 27 additions and 4 deletions.
diff --git a/nullaway/src/main/java/com/uber/nullaway/handlers/LibraryModelsHandler.java b/nullaway/src/main/java/com/uber/nullaway/handlers/LibraryModelsHandler.java
@@ -196,8 +196,9 @@ public NullnessHint onDataflowVisitMethodInvocation(
     setUnconditionalArgumentNullness(bothUpdates, node.getArguments(), callee, state, apContext);
     setConditionalArgumentNullness(
         thenUpdates, elseUpdates, node.getArguments(), callee, state, apContext);
+    OptimizedLibraryModels optLibraryModels = getOptLibraryModels(state.context);
     ImmutableSet<Integer> nullImpliesNullIndexes =
-        getOptLibraryModels(state.context).nullImpliesNullParameters(callee);
+        optLibraryModels.nullImpliesNullParameters(callee);
     if (!nullImpliesNullIndexes.isEmpty()) {
       // If the method is marked as having argument dependent nullability and any of the
       // corresponding arguments is null, then the return is nullable. If the method is
@@ -212,10 +213,9 @@ public NullnessHint onDataflowVisitMethodInvocation(
       return anyNull ? NullnessHint.HINT_NULLABLE : NullnessHint.FORCE_NONNULL;
     }
     Types types = state.getTypes();
-    if (getOptLibraryModels(state.context).hasNonNullReturn(callee, types, !isMethodAnnotated)) {
+    if (optLibraryModels.hasNonNullReturn(callee, types, !isMethodAnnotated)) {
       return NullnessHint.FORCE_NONNULL;
-    } else if (getOptLibraryModels(state.context)
-        .hasNullableReturn(callee, types, !isMethodAnnotated)) {
+    } else if (optLibraryModels.hasNullableReturn(callee, types, !isMethodAnnotated)) {
       return NullnessHint.HINT_NULLABLE;
     } else {
       return NullnessHint.UNKNOWN;
@@ -612,6 +612,7 @@ private static class DefaultLibraryModels implements LibraryModels {
 
     private static final ImmutableSetMultimap<MethodRef, Integer> NULL_IMPLIES_NULL_PARAMETERS =
         new ImmutableSetMultimap.Builder<MethodRef, Integer>()
+            .put(methodRef("java.lang.Class", "cast(java.lang.Object)"), 0)
             .put(methodRef("java.util.Optional", "orElse(T)"), 0)
             .put(methodRef("com.google.common.io.Closer", "<C>register(C)"), 0)
             .put(methodRef("java.util.Map", "getOrDefault(java.lang.Object,V)"), 1)

diff --git a/nullaway/src/test/java/com/uber/nullaway/NullAwayFrameworkTests.java b/nullaway/src/test/java/com/uber/nullaway/NullAwayFrameworkTests.java
@@ -411,4 +411,26 @@ public void mapGetOrDefault() {
         .addSourceLines("Test.java", sourceLines)
         .doTest();
   }
+
+  @Test
+  public void defaultLibraryModelsClassCast() {
+    defaultCompilationHelper
+        .addSourceLines(
+            "Test.java",
+            "package com.uber;",
+            "import org.jspecify.annotations.Nullable;",
+            "class Test {",
+            "  void castNullable(@Nullable String s) {",
+            "    // BUG: Diagnostic contains: dereferenced",
+            "    CharSequence.class.cast(s).hashCode();",
+            "  }",
+            "  void castNonnull(String s1, @Nullable String s2) {",
+            "    CharSequence.class.cast(s1).hashCode();",
+            "    if (s2 instanceof CharSequence) {",
+            "      CharSequence.class.cast(s2).hashCode();",
+            "    }",
+            "  }",
+            "}")
+        .doTest();
+  }
 }