JVM_IR: generate non-null assertions for arguments

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/DeclarationOrigins.kt

@@ -23,7 +23,9 @@ import org.jetbrains.kotlin.ir.expressions.IrStatementOriginImpl
 
 interface JvmLoweredDeclarationOrigin : IrDeclarationOrigin {
     object CLASS_STATIC_INITIALIZER : IrDeclarationOriginImpl("CLASS_STATIC_INITIALIZER")
-    object DEFAULT_IMPLS : IrDeclarationOriginImpl("DEFAULT_IMPL")
+    object DEFAULT_IMPLS : IrDeclarationOriginImpl("DEFAULT_IMPLS")
+    object DEFAULT_IMPLS_BRIDGE : IrDeclarationOriginImpl("DEFAULT_IMPLS_BRIDGE")
+    object DEFAULT_IMPLS_BRIDGE_TO_SYNTHETIC : IrDeclarationOriginImpl("DEFAULT_IMPLS_BRIDGE_TO_SYNTHETIC", isSynthetic = true)
     object FIELD_FOR_OUTER_THIS : IrDeclarationOriginImpl("FIELD_FOR_OUTER_THIS")
     object FUNCTION_REFERENCE_IMPL : IrDeclarationOriginImpl("FUNCTION_REFERENCE_IMPL")
     object SYNTHETIC_ACCESSOR : IrDeclarationOriginImpl("SYNTHETIC_ACCESSOR", isSynthetic = true)

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/ExpressionCodegen.kt

@@ -156,6 +156,7 @@ class ExpressionCodegen(
         val startLabel = markNewLabel()
         val info = BlockInfo()
         val body = irFunction.body!!
+        generateNonNullAssertions()
         val result = body.accept(this, info)
         // If this function has an expression body, return the result of that expression.
         // Otherwise, if it does not end in a return statement, it must be void-returning,
@@ -176,6 +177,27 @@ class ExpressionCodegen(
         mv.visitEnd()
     }
 
+    private fun generateNonNullAssertions() {
+        val isSyntheticOrBridge = irFunction.origin.isSynthetic ||
+                // Although these are accessible from Java, the functions they bridge to already have the assertions.
+                irFunction.origin == IrDeclarationOrigin.BRIDGE_SPECIAL ||
+                irFunction.origin == JvmLoweredDeclarationOrigin.DEFAULT_IMPLS_BRIDGE ||
+                irFunction.origin == JvmLoweredDeclarationOrigin.JVM_STATIC_WRAPPER
+        if (!isInlineLambda && !isSyntheticOrBridge && !Visibilities.isPrivate(irFunction.visibility)) {
+            irFunction.extensionReceiverParameter?.let { generateNonNullAssertion(it) }
+            irFunction.valueParameters.forEach(::generateNonNullAssertion)
+        }
+    }
+
+    private fun generateNonNullAssertion(param: IrValueParameter) {
+        val asmType = param.type.asmType
+        if (!param.type.isNullable() && !isPrimitive(asmType)) {
+            mv.load(findLocalIndex(param.symbol), asmType)
+            mv.aconst(param.name.asString())
+            mv.invokestatic("kotlin/jvm/internal/Intrinsics", "checkParameterIsNotNull", "(Ljava/lang/Object;Ljava/lang/String;)V", false)
+        }
+    }
+
     private fun writeParameterInLocalVariableTable(startLabel: Label, endLabel: Label) {
         if (!irFunction.isStatic) {
             mv.visitLocalVariable("this", classCodegen.type.descriptor, null, startLabel, endLabel, 0)

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/descriptors/JvmDeclarationFactory.kt

@@ -148,7 +148,19 @@ class JvmDeclarationFactory(
             createStaticFunctionWithReceivers(
                 defaultImpls, name, interfaceFun,
                 dispatchReceiverType = parent.defaultType,
-                origin = JvmLoweredDeclarationOrigin.DEFAULT_IMPLS
+                // If `interfaceFun` is not a real implementation, then we're generating stubs in a descendant
+                // interface's DefaultImpls. For example,
+                //
+                //     interface I1 { fun f() { ... } }
+                //     interface I2 : I1
+                //
+                // is supposed to allow using `I2.DefaultImpls.f` as if it was inherited from `I1.DefaultImpls`.
+                // The classes are not actually related and `I2.DefaultImpls.f` is not a fake override but a bridge.
+                origin = when {
+                    interfaceFun.origin != IrDeclarationOrigin.FAKE_OVERRIDE -> interfaceFun.origin
+                    interfaceFun.resolveFakeOverride()!!.origin.isSynthetic -> JvmLoweredDeclarationOrigin.DEFAULT_IMPLS_BRIDGE_TO_SYNTHETIC
+                    else -> JvmLoweredDeclarationOrigin.DEFAULT_IMPLS_BRIDGE
+                }
             )
         }
     }

compiler/testData/codegen/box/builtinStubMethods/mapGetOrDefault/noTypeSafeBridge.kt

@@ -3,6 +3,10 @@
 // FULL_JDK
 // WITH_RUNTIME
 
+// Bridges are not generated because their signatures would conflict. The logic
+// should be inserted directly into existing methods, but this is not implemented.
+// IGNORE_BACKEND: JVM_IR
+
 class A : MutableMap<Any, Any?> {
     override val entries: MutableSet<MutableMap.MutableEntry<Any, Any?>>
         get() = throw UnsupportedOperationException()

compiler/testData/codegen/box/javaInterop/notNullAssertions/extensionReceiverParameter.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JVM_IR
 // TARGET_BACKEND: JVM
 
 // FILE: Test.java

compiler/testData/codegen/box/javaInterop/notNullAssertions/incWithNullabilityAssertionOnExtensionReceiver_lv11.kt

@@ -1,5 +1,4 @@
 // !LANGUAGE: -NullabilityAssertionOnExtensionReceiver
-// IGNORE_BACKEND: JVM_IR
 // TARGET_BACKEND: JVM
 // FILE: test.kt
 // WITH_RUNTIME

compiler/testData/codegen/box/javaInterop/notNullAssertions/incWithNullabilityAssertionOnExtensionReceiver_lv12.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JVM_IR
 // TARGET_BACKEND: JVM
 // FILE: test.kt
 // WITH_RUNTIME

compiler/testData/codegen/box/javaInterop/notNullAssertions/nullabilityAssertionOnExtensionReceiver_lv11.kt

@@ -1,5 +1,4 @@
 // !LANGUAGE: -NullabilityAssertionOnExtensionReceiver
-// IGNORE_BACKEND: JVM_IR
 // TARGET_BACKEND: JVM
 // WITH_RUNTIME
 // FILE: test.kt

compiler/testData/codegen/box/specialBuiltins/emptyMap.kt

@@ -1,3 +1,7 @@
+// Bridges are not generated because their signatures would conflict. The logic
+// should be inserted directly into existing methods, but this is not implemented.
+// IGNORE_BACKEND: JVM_IR
+
 private object EmptyMap : Map<Any, Nothing> {
     override val size: Int get() = 0
     override fun isEmpty(): Boolean = true

compiler/testData/codegen/bytecodeText/inlineClasses/noAssertionsForInlineClassesBasedOnNullableTypes.kt

@@ -1,4 +1,5 @@
 // !LANGUAGE: +InlineClasses
+// IGNORE_BACKEND: JVM_IR
 
 inline class AsAny(val a: Any?)
 

compiler/testData/codegen/bytecodeText/nullCheckOptimization/notNullAsNotNullable.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JVM_IR
 fun foo(s: String) = s as CharSequence
 
 // 0 IFNULL

compiler/testData/codegen/bytecodeText/nullCheckOptimization/redundantSafeCall.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JVM_IR
 fun test(s: String) = s?.length
 
 // 0 IFNULL