Write versions to sources

so as to make recommendation to Kotlin versions.

2 files changed, 53 insertions, 10 deletions

diff --git a/gradle-plugin/build.gradle.kts b/gradle-plugin/build.gradle.kts
index 934cb8bd..41dfe32b 100644
--- a/gradle-plugin/build.gradle.kts
+++ b/gradle-plugin/build.gradle.kts
@@ -123,3 +123,36 @@ tasks.named<Test>("test").configure {
     dependsOn(":gradle-plugin:publishAllPublicationsToTestRepository")
     dependsOn(":symbol-processing:publishAllPublicationsToTestRepository")
 }
+
+abstract class WriteVersionSrcTask @Inject constructor(
+    @get:Input val kspVersion: String,
+    @get:Input val kotlinVersion: String,
+    @get:org.gradle.api.tasks.OutputDirectory val outputSrcDir: File
+) : DefaultTask() {
+    @TaskAction
+    fun generate() {
+        File(outputSrcDir, "KSPVersions.kt").writeText(
+            """
+            package com.google.devtools.ksp.gradle
+            val KSP_KOTLIN_BASE_VERSION = "$kotlinVersion"
+            val KSP_VERSION = "$kspVersion"
+            """.trimIndent()
+        )
+    }
+}
+
+val kspVersionDir = File(project.buildDir, "generated/ksp-versions")
+val writeVersionSrcTask = tasks.register<WriteVersionSrcTask>(
+    "generateKSPVersions",
+    version.toString(),
+    kotlinBaseVersion,
+    kspVersionDir
+)
+
+kotlin {
+    sourceSets {
+        main {
+            kotlin.srcDir(writeVersionSrcTask.map { it.outputSrcDir })
+        }
+    }
+}
diff --git a/gradle-plugin/src/main/kotlin/com/google/devtools/ksp/gradle/KspSubplugin.kt b/gradle-plugin/src/main/kotlin/com/google/devtools/ksp/gradle/KspSubplugin.kt
index b273a6ce..6d5b0fe4 100644
--- a/gradle-plugin/src/main/kotlin/com/google/devtools/ksp/gradle/KspSubplugin.kt
+++ b/gradle-plugin/src/main/kotlin/com/google/devtools/ksp/gradle/KspSubplugin.kt
@@ -40,6 +40,7 @@ import org.gradle.api.tasks.compile.JavaCompile
 import org.gradle.language.jvm.tasks.ProcessResources
 import org.gradle.tooling.provider.model.ToolingModelBuilderRegistry
 import org.gradle.util.GradleVersion
+import org.gradle.util.internal.VersionNumber
 import org.gradle.work.Incremental
 import org.jetbrains.kotlin.cli.common.arguments.*
 import org.jetbrains.kotlin.gradle.dsl.*
@@ -141,16 +142,25 @@ class KspGradleSubplugin @Inject internal constructor(private val registry: Tool
 
     override fun isApplicable(kotlinCompilation: KotlinCompilation<*>): Boolean {
         val project = kotlinCompilation.target.project
-        val kspVersion = javaClass.`package`.implementationVersion
-        val kotlinVersion = project.getKotlinPluginVersion() ?: "N/A"
+        val kspVersion = VersionNumber.parse(KSP_KOTLIN_BASE_VERSION)
+        val kotlinVersion = VersionNumber.parse(project.getKotlinPluginVersion())
 
         // Check version and show warning by default.
         val noVersionCheck = project.findProperty("ksp.version.check")?.toString()?.toBoolean() == false
-        if (!noVersionCheck && !kspVersion.startsWith(kotlinVersion))
-            project.logger.warn(
-                "ksp-$kspVersion might not work with kotlin-$kotlinVersion properly. " +
-                    "Please pick the same version of ksp and kotlin plugins."
-            )
+        if (!noVersionCheck) {
+            if (kspVersion < kotlinVersion) {
+                project.logger.warn(
+                    "ksp-$KSP_VERSION is too old for kotlin-$kotlinVersion. " +
+                        "Please upgrade ksp or downgrade kotlin-gradle-plugin to $KSP_KOTLIN_BASE_VERSION."
+                )
+            }
+            if (kspVersion > kotlinVersion) {
+                project.logger.warn(
+                    "ksp-$KSP_VERSION is too new for kotlin-$kotlinVersion. " +
+                        "Please upgrade kotlin-gradle-plugin to $KSP_KOTLIN_BASE_VERSION."
+                )
+            }
+        }
 
         return true
     }
@@ -330,17 +340,17 @@ class KspGradleSubplugin @Inject internal constructor(private val registry: Tool
         SubpluginArtifact(
             groupId = "com.google.devtools.ksp",
             artifactId = KSP_ARTIFACT_NAME,
-            version = javaClass.`package`.implementationVersion
+            version = KSP_VERSION
         )
 
     override fun getPluginArtifactForNative(): SubpluginArtifact? =
         SubpluginArtifact(
             groupId = "com.google.devtools.ksp",
             artifactId = KSP_ARTIFACT_NAME_NATIVE,
-            version = javaClass.`package`.implementationVersion
+            version = KSP_VERSION
         )
 
-    val apiArtifact = "com.google.devtools.ksp:symbol-processing-api:${javaClass.`package`.implementationVersion}"
+    val apiArtifact = "com.google.devtools.ksp:symbol-processing-api:$KSP_VERSION"
 }
 
 private val artifactType = Attribute.of("artifactType", String::class.java)