From 838caff522c9c47b3147d6d0d125c38e3d5561e9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cl=C3=A9ment=20Fournier?= <clement.fournier76@gmail.com>
Date: Wed, 3 May 2023 21:50:18 +0200
Subject: [PATCH] Fix scope of static interface methods

---
 .../symbols/table/internal/JavaResolvers.java |  8 +++
 .../table/internal/MemberInheritanceTest.kt   | 53 +++++++++++++++++--
 2 files changed, 57 insertions(+), 4 deletions(-)

diff --git a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/symbols/table/internal/JavaResolvers.java b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/symbols/table/internal/JavaResolvers.java
index ee8fb653b7..58ca8ae7d1 100644
--- a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/symbols/table/internal/JavaResolvers.java
+++ b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/symbols/table/internal/JavaResolvers.java
@@ -128,9 +128,17 @@ public final class JavaResolvers {
                 return t.streamMethods(
                     it -> it.nameEquals(simpleName)
                         && isAccessibleIn(nestRoot, it, true) // fetch protected methods
+                        && isNotStaticInterfaceMethod(it)
                 ).collect(OverloadSet.collectMostSpecific(t)); // remove overridden, hidden methods
             }
 
+            // Static interface methods are not inherited and are in fact not in scope in the subtypes.
+            // They must be explicitly qualified or imported.
+            private boolean isNotStaticInterfaceMethod(JMethodSymbol it) {
+                return !it.isStatic() || it.getEnclosingClass() == t.getSymbol()
+                    || !it.getEnclosingClass().isInterface();
+            }
+
             @Override
             public String toString() {
                 return "methods of " + t;
diff --git a/pmd-java/src/test/kotlin/net/sourceforge/pmd/lang/java/symbols/table/internal/MemberInheritanceTest.kt b/pmd-java/src/test/kotlin/net/sourceforge/pmd/lang/java/symbols/table/internal/MemberInheritanceTest.kt
index 090ff282b0..233f4cc299 100644
--- a/pmd-java/src/test/kotlin/net/sourceforge/pmd/lang/java/symbols/table/internal/MemberInheritanceTest.kt
+++ b/pmd-java/src/test/kotlin/net/sourceforge/pmd/lang/java/symbols/table/internal/MemberInheritanceTest.kt
@@ -15,10 +15,7 @@ import net.sourceforge.pmd.lang.ast.test.component8
 import net.sourceforge.pmd.lang.ast.test.shouldMatchN
 import net.sourceforge.pmd.lang.java.ast.*
 import net.sourceforge.pmd.lang.java.symbols.table.coreimpl.ShadowChain
-import net.sourceforge.pmd.lang.java.types.JClassType
-import net.sourceforge.pmd.lang.java.types.JVariableSig
-import net.sourceforge.pmd.lang.java.types.shouldHaveType
-import net.sourceforge.pmd.lang.java.types.typeDsl
+import net.sourceforge.pmd.lang.java.types.*
 
 @Suppress("UNUSED_VARIABLE")
 class MemberInheritanceTest : ParserTestSpec({
@@ -765,4 +762,52 @@ class Top {
         importedMethodCall.methodType.symbol shouldBe importedMethodSym
     }
 
+
+    parserTest("Static methods of interfaces are not in scope in subclasses") {
+        // This is what allows the import below to not be shadowed by the inherited declaration
+        // This was tested with javac. The intellij compiler doesn't understand this code.
+
+        val acu = parser.withProcessing().parse("""
+package p;
+
+import static p.Top2.foo;
+
+class Klass implements Top {
+  static {
+    foo(); // This is Top2.foo 
+  }
+  
+  static class Child {
+      {
+        foo(); // This is also Top2.foo
+      }
+  }
+}
+interface Top {
+    static void foo() {}
+
+    static void bar() {
+        foo(); // just test that this is not the import
+    }
+}
+interface Top2 {
+    static void foo() {}
+}
+        """)
+
+        val (fooInTop1, _, fooInTop2) = acu.methodDeclarations().toList()
+        val (call1, call2, callInBar) = acu.methodCalls().crossFindBoundaries().toList()
+
+        withClue(call1) {
+            call1.methodType.symbol shouldBe fooInTop2.symbol
+        }
+        withClue(call2) {
+            call2.methodType.symbol shouldBe fooInTop2.symbol
+        }
+        withClue(callInBar) {
+            callInBar.methodType.symbol shouldBe fooInTop1.symbol
+        }
+
+    }
+
 })