From 7cbdeb43b6120b5c8fb2ab9802bc0e0cb8d5efac Mon Sep 17 00:00:00 2001
From: Liam Miller-Cushon <cushon@google.com>
Date: Fri, 5 Jan 2024 09:05:09 -0800
Subject: [PATCH] Make AutoBuilder produce an error if it encounters a
 `@Nullable` primitive parameter

RELNOTES=AutoBuilder now reports an error if it encounters a `@Nullable` primitive parameter. Primitive types cannot be `null`, and should not be annotated for nullness.
PiperOrigin-RevId: 596009085
---
 .../value/processor/AutoBuilderProcessor.java | 21 ++++++----
 .../processor/AutoBuilderCompilationTest.java | 40 +++++++++++++++++++
 2 files changed, 54 insertions(+), 7 deletions(-)

diff --git a/value/src/main/java/com/google/auto/value/processor/AutoBuilderProcessor.java b/value/src/main/java/com/google/auto/value/processor/AutoBuilderProcessor.java
index 607e7367b9..35e67900fc 100644
--- a/value/src/main/java/com/google/auto/value/processor/AutoBuilderProcessor.java
+++ b/value/src/main/java/com/google/auto/value/processor/AutoBuilderProcessor.java
@@ -298,13 +298,20 @@ private ImmutableSet<Property> propertySet(
         .map(
             v -> {
               String name = v.getSimpleName().toString();
-              return newProperty(
-                  v,
-                  identifiers.get(v),
-                  propertyToGetterName.get(name),
-                  Optional.ofNullable(builderInitializers.get(name)),
-                  executable.isOptional(name),
-                  nullables);
+              Property p =
+                  newProperty(
+                      v,
+                      identifiers.get(v),
+                      propertyToGetterName.get(name),
+                      Optional.ofNullable(builderInitializers.get(name)),
+                      executable.isOptional(name),
+                      nullables);
+              if (p.isNullable() && v.asType().getKind().isPrimitive()) {
+                errorReporter()
+                    .reportError(
+                        v, "[AutoBuilderNullPrimitive] Primitive types cannot be @Nullable");
+              }
+              return p;
             })
         .collect(toImmutableSet());
   }
diff --git a/value/src/test/java/com/google/auto/value/processor/AutoBuilderCompilationTest.java b/value/src/test/java/com/google/auto/value/processor/AutoBuilderCompilationTest.java
index c85deb5a46..a850d171cb 100644
--- a/value/src/test/java/com/google/auto/value/processor/AutoBuilderCompilationTest.java
+++ b/value/src/test/java/com/google/auto/value/processor/AutoBuilderCompilationTest.java
@@ -872,6 +872,46 @@ public void nullableSetterForNonNullableParameter() {
         .onLineContaining("thing(@Nullable String x)");
   }
 
+  @Test
+  public void nullablePrimitiveParameter() {
+    JavaFileObject javaFileObject =
+        JavaFileObjects.forSourceLines(
+            "foo.bar.Baz",
+            "package foo.bar;",
+            "",
+            "import com.google.auto.value.AutoBuilder;",
+            "import com.example.annotations.Nullable;",
+            "",
+            "class Baz {",
+            "  Baz(@Nullable int thing) {}",
+            "",
+            "  @AutoBuilder",
+            "  interface Builder {",
+            "    abstract Builder thing(int x);",
+            "    abstract Baz build();",
+            "  }",
+            "}");
+    JavaFileObject nullableFileObject =
+        JavaFileObjects.forSourceLines(
+            "com.example.annotations.Nullable",
+            "package com.example.annotations;",
+            "",
+            "import java.lang.annotation.ElementType;",
+            "import java.lang.annotation.Target;",
+            "",
+            "@Target(ElementType.TYPE_USE)",
+            "public @interface Nullable {}");
+    Compilation compilation =
+        javac()
+            .withProcessors(new AutoBuilderProcessor())
+            .compile(javaFileObject, nullableFileObject);
+    assertThat(compilation).failed();
+    assertThat(compilation)
+        .hadErrorContaining("[AutoBuilderNullPrimitive] Primitive types cannot be @Nullable")
+        .inFile(javaFileObject)
+        .onLineContaining("Baz(@Nullable int thing)");
+  }
+
   @Test
   public void setterWrongType() {
     JavaFileObject javaFileObject =