feature: support VarHandle-producing methods from MH.Lookup (#97)

SirYwell · Jun 23, 2024 · ccb94ad · ccb94ad
1 parent 4c2a3b5
commit ccb94ad
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Showing 5 changed files with 62 additions and 7 deletions.
diff --git a/src/main/kotlin/de/sirywell/handlehints/dfa/SsaAnalyzer.kt b/src/main/kotlin/de/sirywell/handlehints/dfa/SsaAnalyzer.kt
@@ -250,7 +250,7 @@ class SsaAnalyzer(private val controlFlow: ControlFlow, val typeData: TypeData)
         expression: PsiMethodCallExpression,
         arguments: List<PsiExpression>,
         block: Block
-    ): MethodHandleType? {
+    ): TypeLatticeElement<*>? {
         return when (expression.methodName) {
             "findConstructor" -> {
                 if (arguments.size != 2) return noMatch()
@@ -281,6 +281,8 @@ class SsaAnalyzer(private val controlFlow: ControlFlow, val typeData: TypeData)
                 val t = type.methodHandleType(block) ?: return notConstant()
                 lookupHelper.findVirtual(refc, name, t)
             }
+            "findStaticVarHandle" -> findAccessor(arguments, lookupHelper::findStaticVarHandle)
+            "findVarHandle" -> findAccessor(arguments, lookupHelper::findVarHandle)
 
             "accessClass",
             "defineClass",
@@ -289,8 +291,6 @@ class SsaAnalyzer(private val controlFlow: ControlFlow, val typeData: TypeData)
             "dropLookupMode",
             "ensureInitialized",
             "findClass",
-            "findStaticVarHandle",
-            "findVarHandle",
             "hasFullPrivilegeAccess",
             "hasPrivateAccess",
             "in",
@@ -310,10 +310,10 @@ class SsaAnalyzer(private val controlFlow: ControlFlow, val typeData: TypeData)
         }
     }
 
-    private fun findAccessor(
+    private fun <T> findAccessor(
         arguments: List<PsiExpression>,
-        resolver: (PsiExpression, PsiExpression) -> MethodHandleType
-    ): MethodHandleType? {
+        resolver: (PsiExpression, PsiExpression) -> T
+    ): T? {
         if (arguments.size != 3) return noMatch()
         val (refc, _, type) = arguments
         return resolver(refc, type)
@@ -524,7 +524,7 @@ class SsaAnalyzer(private val controlFlow: ControlFlow, val typeData: TypeData)
         }
     }
 
-    private fun noMatch(): MethodHandleType? {
+    private fun <T: TypeLatticeElement<*>> noMatch(): T? {
         return null
     }
 

diff --git a/src/main/kotlin/de/sirywell/handlehints/mhtype/LookupHelper.kt b/src/main/kotlin/de/sirywell/handlehints/mhtype/LookupHelper.kt
@@ -138,4 +138,16 @@ class LookupHelper(private val ssaAnalyzer: SsaAnalyzer) : ProblemEmitter(ssaAna
         }
         return MethodHandleType(signature)
     }
+
+    fun findStaticVarHandle(declExpr: PsiExpression, typeExpr: PsiExpression): VarHandleType {
+        declExpr.asReferenceType() // problem reporting only, not needed otherwise
+        val type = typeExpr.asNonVoidType()
+        return CompleteVarHandleType(type, CompleteParameterList(listOf()))
+    }
+
+    fun findVarHandle(recvExpr: PsiExpression, typeExpr: PsiExpression): VarHandleType {
+        val recv = recvExpr.asReferenceType()
+        val type = typeExpr.asNonVoidType()
+        return CompleteVarHandleType(type, CompleteParameterList(listOf(recv)))
+    }
 }
diff --git a/src/test/kotlin/de/sirywell/handlehints/mhtype/MethodHandleInspectionsTest.kt b/src/test/kotlin/de/sirywell/handlehints/mhtype/MethodHandleInspectionsTest.kt
@@ -49,6 +49,10 @@ class MethodHandleInspectionsTest : LightJavaCodeInsightFixtureTestCase() {
 
     fun testLookupFindStaticSetter() = doTypeCheckingTest()
 
+    fun testLookupFindStaticVarHandle() = doTypeCheckingTest()
+
+    fun testLookupFindVarHandle() = doTypeCheckingTest()
+
     fun testLookupFindVirtual() = doTypeCheckingTest()
 
     fun testMethodHandlesArrayConstructor() = doTypeCheckingTest()

diff --git a/src/test/testData/LookupFindStaticVarHandle.java b/src/test/testData/LookupFindStaticVarHandle.java
@@ -0,0 +1,19 @@
+import java.lang.invoke.MethodHandles;
+import java.lang.invoke.MethodHandles.Lookup;
+import java.lang.invoke.MethodType;
+import java.lang.invoke.VarHandle;
+
+class LookupFindStaticVarHandle {
+  static {
+    try {
+      // valid
+      <info descr="()(Boolean)">VarHandle vh0 = <info descr="()(Boolean)">MethodHandles.lookup().findStaticVarHandle(Boolean.class, "FALSE", Boolean.class)</info>;</info>
+      // invalid - field cannot be of type void
+      <info descr="()(⊤)">VarHandle vh1 = <info descr="()(⊤)">MethodHandles.lookup().findStaticVarHandle(Boolean.class, "FALSE", void.class)</info>;</info>
+      // invalid - target class cannot be void
+      <info descr="()(Boolean)">VarHandle vh2 = <info descr="()(Boolean)">MethodHandles.lookup().findStaticVarHandle(void.class, "FALSE", Boolean.class)</info>;</info>
+      // invalid - target class cannot be int
+      <info descr="()(Boolean)">VarHandle vh3 = <info descr="()(Boolean)">MethodHandles.lookup().findStaticVarHandle(int.class, "FALSE", Boolean.class)</info>;</info>
+    } catch (Throwable ignored) {}
+  }
+}
diff --git a/src/test/testData/LookupFindVarHandle.java b/src/test/testData/LookupFindVarHandle.java
@@ -0,0 +1,20 @@
+import java.lang.invoke.MethodHandles;
+import java.lang.invoke.MethodHandles.Lookup;
+import java.lang.invoke.MethodType;
+import java.lang.invoke.VarHandle;
+
+class LookupFindVarHandle {
+  int myField;
+  static {
+    try {
+      // valid
+      <info descr="(LookupFindVarHandle)(int)">VarHandle vh0 = <info descr="(LookupFindVarHandle)(int)">MethodHandles.lookup().findVarHandle(LookupFindVarHandle.class, "myField", int.class)</info>;</info>
+      // invalid - field cannot be of type void
+      <info descr="(LookupFindVarHandle)(⊤)">VarHandle vh1 = <info descr="(LookupFindVarHandle)(⊤)">MethodHandles.lookup().findVarHandle(LookupFindVarHandle.class, "myField", void.class)</info>;</info>
+      // invalid - target class cannot be void
+      <info descr="(⊤)(int)">VarHandle vh2 = <info descr="(⊤)(int)">MethodHandles.lookup().findVarHandle(void.class, "myField", int.class)</info>;</info>
+      // invalid - target class cannot be int
+      <info descr="(⊤)(int)">VarHandle vh3 = <info descr="(⊤)(int)">MethodHandles.lookup().findVarHandle(int.class, "myField", int.class)</info>;</info>
+    } catch (Throwable ignored) {}
+  }
+}