[WIP] feat: @ZiplineId

zipline-kotlin-plugin/src/main/kotlin/app/cash/zipline/api/fir/FirZiplineApiReader.kt

@@ -19,15 +19,18 @@ import app.cash.zipline.kotlin.BridgedInterface.Companion.NON_INTERFACE_FUNCTION
 import app.cash.zipline.kotlin.FqPackageName
 import app.cash.zipline.kotlin.classId
 import java.io.File
+import org.jetbrains.kotlin.fir.FirAnnotationContainer
 import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.analysis.checkers.isSupertypeOf
 import org.jetbrains.kotlin.fir.analysis.checkers.toRegularClassSymbol
 import org.jetbrains.kotlin.fir.declarations.FirDeclaration
 import org.jetbrains.kotlin.fir.declarations.FirFunction
 import org.jetbrains.kotlin.fir.declarations.FirProperty
 import org.jetbrains.kotlin.fir.declarations.FirRegularClass
+import org.jetbrains.kotlin.fir.declarations.getAnnotationByClassId
 import org.jetbrains.kotlin.fir.declarations.utils.isInterface
 import org.jetbrains.kotlin.fir.declarations.utils.isSuspend
+import org.jetbrains.kotlin.fir.expressions.FirConstExpression
 import org.jetbrains.kotlin.fir.pipeline.FirResult
 import org.jetbrains.kotlin.fir.resolve.providers.symbolProvider
 import org.jetbrains.kotlin.fir.symbols.impl.FirClassLikeSymbol
@@ -39,6 +42,8 @@ import org.jetbrains.kotlin.fir.types.FirTypeProjectionWithVariance
 import org.jetbrains.kotlin.fir.types.FirTypeRef
 import org.jetbrains.kotlin.fir.types.FirUserTypeRef
 import org.jetbrains.kotlin.types.Variance
+import org.jetbrains.kotlin.utils.addToStdlib.UnsafeCastFunction
+import org.jetbrains.kotlin.utils.addToStdlib.cast
 
 fun readFirZiplineApi(
  sources: Collection<File>,
@@ -52,6 +57,7 @@ fun readFirZiplineApi(
 
 private val ziplineFqPackage = FqPackageName("app.cash.zipline")
 private val ziplineServiceClassId = ziplineFqPackage.classId("ZiplineService")
+private val ziplineIdClassId = ziplineFqPackage.classId("ZiplineId")
 
 /**
  * Read the frontend intermediate representation of a program and emit its ZiplineService
@@ -128,16 +134,19 @@ internal class FirZiplineApiReader(
  append(valueParameters.joinToString { it.returnTypeRef.asString() })
  append("): ${returnTypeRef.asString()}")
  }
-
- return FirZiplineFunction(signature)
+ return getZiplineId()?.let {
+ FirZiplineFunction(it, signature)
+ } ?: FirZiplineFunction(signature)
  }
 
  private fun FirProperty.asDeclaredZiplineFunction(): FirZiplineFunction {
  val signature = when {
  isVar -> "var ${symbol.name.identifier}: ${returnTypeRef.asString()}"
  else -> "val ${symbol.name.identifier}: ${returnTypeRef.asString()}"
  }
- return FirZiplineFunction(signature)
+ return getZiplineId()?.let {
+ FirZiplineFunction(it,signature)
+ } ?: FirZiplineFunction(signature)
  }
 
  /** See [app.cash.zipline.kotlin.asString]. */
@@ -177,6 +186,14 @@ internal class FirZiplineApiReader(
  }
  }
 
+ @OptIn(UnsafeCastFunction::class)
+ private fun FirAnnotationContainer.getZiplineId(): String? {
+ return getAnnotationByClassId(
+ ziplineIdClassId,
+ session
+ )?.cast<FirConstExpression<String>>()?.value
+ }
+
  private fun List<FirDeclaration>.findRegularClassesRecursive(): List<FirRegularClass> {
  val classes = filterIsInstance<FirRegularClass>()
  return classes + classes.flatMap { it.declarations.findRegularClassesRecursive() }

zipline-kotlin-plugin/src/main/kotlin/app/cash/zipline/kotlin/ir.kt

@@ -46,6 +46,7 @@ import org.jetbrains.kotlin.ir.declarations.IrDeclarationOrigin
 import org.jetbrains.kotlin.ir.declarations.IrFile
 import org.jetbrains.kotlin.ir.declarations.IrProperty
 import org.jetbrains.kotlin.ir.declarations.IrSimpleFunction
+import org.jetbrains.kotlin.ir.expressions.IrConst
 import org.jetbrains.kotlin.ir.expressions.IrDelegatingConstructorCall
 import org.jetbrains.kotlin.ir.expressions.IrExpression
 import org.jetbrains.kotlin.ir.expressions.IrExpressionBody
@@ -72,8 +73,11 @@ import org.jetbrains.kotlin.ir.util.constructors
 import org.jetbrains.kotlin.ir.util.createDispatchReceiverParameter
 import org.jetbrains.kotlin.ir.util.createImplicitParameterDeclarationWithWrappedDescriptor
 import org.jetbrains.kotlin.ir.util.defaultType
+import org.jetbrains.kotlin.ir.util.getAnnotation
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.name.StandardClassIds
+import org.jetbrains.kotlin.utils.addToStdlib.UnsafeCastFunction
+import org.jetbrains.kotlin.utils.addToStdlib.cast
 
 /** Returns a string as specified by ZiplineFunction.signature. */
 internal val IrSimpleFunction.signature: String
@@ -102,9 +106,23 @@ internal val IrSimpleFunction.signature: String
  }
  }
 
+@UnsafeCastFunction
+private fun <T> IrElement.getConstValue(): T {
+ return cast<IrConst<T>>().value
+}
+
+private val ziplineFqPackageName = FqPackageName("app.cash.zipline")
+private val ziplineIdAnnotationFqName = ziplineFqPackageName.classId("ZiplineId").asSingleFqName()
+
+
 /** Returns a string as specified by ZiplineFunction.id. */
+@OptIn(UnsafeCastFunction::class)
 internal val IrSimpleFunction.id: String
- get() = signature.signatureHash()
+ get() {
+
+ return getAnnotation(ziplineIdAnnotationFqName)?.getValueArgument(0)
+ ?.getConstValue() ?: signature.signatureHash()
+ }
 
 /** Thrown on invalid or unexpected input code. */
 class ZiplineCompilationException(

zipline/src/commonMain/kotlin/app/cash/zipline/ZiplineFunction.kt

@@ -21,7 +21,7 @@ package app.cash.zipline
 interface ZiplineFunction<T : ZiplineService> {
  /**
  * A unique id for this function. By default this is the first 6 bytes of the SHA-256 of the
- * function's signature, base64-encoded.
+ * function's signature, base64-encoded. To provide your own id, annotate your function with [ZiplineId].
  *
  * These are sample values that correspond to the sample values in [signature].
  *

zipline/src/commonMain/kotlin/app/cash/zipline/ZiplineId.kt

@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2023 Cash App
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package app.cash.zipline
+
+@Target(AnnotationTarget.FUNCTION)
+@Retention(AnnotationRetention.SOURCE)
+@MustBeDocumented
+// TODO document usage
+annotation class ZiplineId(val id: String)

zipline/src/jniTest/kotlin/app/cash/zipline/NewServicesTest.kt

@@ -411,6 +411,18 @@ class NewSerializersTest {
  suspend fun echo(): @Contextual RequiresContextual
  }
 
+ @Test
+ fun ziplineIdIsAppliedToGeneratedService() {
+ val function =
+ onlyZiplineFunction(serviceSerializer = ziplineServiceSerializer<SimpleZiplineService>()) as ZiplineFunction<*>
+
+ assertEquals(function.id, testZiplineId)
+ }
+ interface SimpleZiplineService : ZiplineService {
+ @ZiplineId(testZiplineId)
+ fun annotatedFunction()
+ }
+
  private fun <T> suspendCallbackSerializer(
  resultSerializer: KSerializer<T>,
  ): KSerializer<SuspendCallback<T>> {
@@ -475,4 +487,7 @@ class NewSerializersTest {
  json.decodeFromString(actual, json.encodeToString(expected, sampleValue)),
  )
  }
+ companion object {
+ private const val testZiplineId = "TEST_ZIPLINE_ID"
+ }
 }