Rewrite how compiler args are passed (#3115)

The cause is that tasks.withType(...) affects primarily platform compilations and may not affect model imported in the IDE, leading to inconsistencies in the IDE analysis of non-platform source sets.

Author: sandwwraith

benchmark/build.gradle.kts

@@ -1,7 +1,3 @@
-import org.gradle.kotlin.dsl.support.*
-import org.jetbrains.kotlin.gradle.dsl.*
-import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
-
 /*
  * Copyright 2017-2021 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
  */
@@ -47,11 +43,9 @@ tasks.assemble {
 
 kotlin {
     compilerOptions {
-        jvmTarget = JvmTarget.JVM_1_8
-        if (overriddenLanguageVersion != null) {
-            languageVersion = KotlinVersion.fromVersion(overriddenLanguageVersion!!)
-            freeCompilerArgs.add("-Xsuppress-version-warnings")
-        }
+        defaultOptions()
+        setJava8Compatible()
+        languageVersion(overriddenLanguageVersion)
     }
 }
 

build.gradle.kts

@@ -83,7 +83,7 @@ tasks.named("knitPrepare") {
 // == compiler flags setup ==
 
 subprojects {
-    apply(plugin = "global-compiler-options")
+    apply(plugin = "cli-compiler-options")
 }
 
 // == TeamCity setup ==

buildSrc/src/main/kotlin/CompilerOptions.kt

@@ -0,0 +1,33 @@
+import org.gradle.kotlin.dsl.assign
+import org.jetbrains.kotlin.gradle.dsl.JvmTarget
+import org.jetbrains.kotlin.gradle.dsl.KotlinCommonCompilerOptions
+import org.jetbrains.kotlin.gradle.dsl.KotlinJvmCompilerOptions
+import org.jetbrains.kotlin.gradle.dsl.KotlinVersion
+
+/*
+ * Copyright 2017-2025 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+val defaultCompilerArgs
+    get() = listOf(
+        "-P", "plugin:org.jetbrains.kotlinx.serialization:disableIntrinsic=false",
+        "-Xreport-all-warnings",
+        "-Xrender-internal-diagnostic-names",
+        "-Xreturn-value-checker=full",
+    )
+
+fun KotlinCommonCompilerOptions.defaultOptions() {
+    freeCompilerArgs.addAll(defaultCompilerArgs)
+}
+
+fun KotlinJvmCompilerOptions.setJava8Compatible() {
+    jvmTarget = JvmTarget.JVM_1_8
+    freeCompilerArgs.addAll("-Xjdk-release=1.8")
+}
+
+fun KotlinCommonCompilerOptions.languageVersion(overriddenLanguageVersion: String?) {
+    if (overriddenLanguageVersion != null) {
+        languageVersion = KotlinVersion.fromVersion(overriddenLanguageVersion)
+        freeCompilerArgs.add("-Xsuppress-version-warnings")
+    }
+}

…otlin/global-compiler-options.gradle.kts …n/kotlin/cli-compiler-options.gradle.ktsbuildSrc/src/main/kotlin/global-compiler-options.gradle.kts renamed to buildSrc/src/main/kotlin/cli-compiler-options.gradle.kts buildSrc/src/main/kotlin/global-compiler-options.gradle.kts renamed to buildSrc/src/main/kotlin/cli-compiler-options.gradle.kts

@@ -5,25 +5,28 @@
 import org.jetbrains.kotlin.gradle.tasks.*
 import kotlin.collections.joinToString
 
+/**
+ * This file is intended for compiler options that affect CLI compilation only.
+ * The reason is that tasks.withType(...) affects only platform compilations,
+ * so you may get incorrect analysis results in IDE on 'intermediate' source sets.
+ *
+ * If compiler option is likely to affect IDE (e.g., new diagnostic or language feature),
+ * add it to CompilerOptions.kt instead.
+ */
+
+// Used only for User Projects TeamCity configurations, no IDE there
 val kotlinAdditionalCliOptions = providers.gradleProperty("kotlin_additional_cli_options")
     .orNull?.let { options ->
         options.removeSurrounding("\"").split(" ").filter { it.isNotBlank() }
     }
 
-val globalCompilerArgs
-    get() = listOf(
-        "-P", "plugin:org.jetbrains.kotlinx.serialization:disableIntrinsic=false",
-        "-Xreport-all-warnings",
-        "-Xrender-internal-diagnostic-names",
-        "-Xreturn-value-checker=full",
-    )
-
 val kotlin_Werror_override: String? by project
 
+// -Werror option only for test source sets
+// Cannot migrate to general compilerOptions {} because we need compilation task name
+// to know whether it is main or test SS.
 tasks.withType(KotlinCompilationTask::class).configureEach {
     compilerOptions {
-        // Unconditional compiler options
-        freeCompilerArgs.addAll(globalCompilerArgs)
         kotlinAdditionalCliOptions?.forEach { option -> freeCompilerArgs.add(option) }
 
         val isMainTaskName = name.startsWith("compileKotlin")

buildSrc/src/main/kotlin/source-sets-conventions.gradle.kts

@@ -5,7 +5,6 @@
 import org.gradle.kotlin.dsl.*
 import org.jetbrains.kotlin.gradle.*
 import org.jetbrains.kotlin.gradle.dsl.*
-import org.jetbrains.kotlin.gradle.tasks.*
 
 plugins {
     kotlin("multiplatform")
@@ -20,11 +19,24 @@ internal fun Project.versionCatalog(): VersionCatalog = versionCatalogs.named("l
 kotlin {
     explicitApi()
 
+    compilerOptions {
+        progressiveMode = true
+        optIn.addAll(
+            listOf(
+                "kotlin.ExperimentalMultiplatform",
+                "kotlin.ExperimentalSubclassOptIn",
+                "kotlinx.serialization.InternalSerializationApi",
+                "kotlinx.serialization.SealedSerializationApi",
+            )
+        )
+        defaultOptions()
+        languageVersion(overriddenLanguageVersion)
+        freeCompilerArgs.add("-Xexpect-actual-classes")
+    }
+
     jvm {
-        @OptIn(ExperimentalKotlinGradlePluginApi::class)
         compilerOptions {
-            jvmTarget = JvmTarget.JVM_1_8
-            freeCompilerArgs.addAll("-Xjdk-release=1.8")
+            setJava8Compatible()
         }
     }
     jvmToolchain(jdkToolchainVersion)
@@ -38,7 +50,6 @@ kotlin {
             }
         }
 
-        @OptIn(ExperimentalKotlinGradlePluginApi::class)
         compilerOptions {
             sourceMap = true
             moduleKind = JsModuleKind.MODULE_UMD
@@ -60,26 +71,6 @@ kotlin {
         resources.srcDirs("$name/resources")
     }
 
-    compilerOptions {
-        // These configuration replaces 'languageSettings' config on line 67
-        progressiveMode.set(true)
-        optIn.addAll(
-            listOf(
-                "kotlin.ExperimentalMultiplatform",
-                "kotlin.ExperimentalSubclassOptIn",
-                "kotlinx.serialization.InternalSerializationApi",
-                "kotlinx.serialization.SealedSerializationApi",
-            )
-        )
-        if (overriddenLanguageVersion != null) {
-            languageVersion = KotlinVersion.fromVersion(overriddenLanguageVersion!!)
-            freeCompilerArgs.add("-Xsuppress-version-warnings")
-        }
-        freeCompilerArgs.add("-Xexpect-actual-classes")
-        // for some reason, IDE does not enable feature in test source sets without this line:
-        freeCompilerArgs.add("-Xreturn-value-checker=full")
-    }
-
     sourceSets {
         commonMain {
             dependencies {

formats/hocon/build.gradle.kts

@@ -1,6 +1,4 @@
-import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 import Java9Modularity.configureJava9ModuleInfo
-import org.jetbrains.kotlin.gradle.dsl.*
 
 
 /*
@@ -17,20 +15,12 @@ kotlin {
     jvmToolchain(jdkToolchainVersion)
 
     compilerOptions {
-        jvmTarget = JvmTarget.JVM_1_8
-        if (overriddenLanguageVersion != null) {
-            languageVersion = KotlinVersion.fromVersion(overriddenLanguageVersion!!)
-            freeCompilerArgs.add("-Xsuppress-version-warnings")
-        }
-        freeCompilerArgs.addAll("-Xjdk-release=1.8")
-    }
-
-    sourceSets.all {
-        languageSettings {
-            progressiveMode = true
+        defaultOptions()
+        setJava8Compatible()
+        languageVersion(overriddenLanguageVersion)
 
-            optIn("kotlinx.serialization.InternalSerializationApi")
-        }
+        progressiveMode = true
+        optIn.add("kotlinx.serialization.InternalSerializationApi")
     }
 }
 

guide/build.gradle.kts

@@ -11,13 +11,12 @@ plugins {
 }
 
 kotlin {
-    jvmToolchain(8)
+    jvmToolchain(jdkToolchainVersion)
 
     compilerOptions {
-        if (overriddenLanguageVersion != null) {
-            languageVersion = KotlinVersion.fromVersion(overriddenLanguageVersion!!)
-            freeCompilerArgs.add("-Xsuppress-version-warnings")
-        }
+        defaultOptions()
+        // Do not set jvmTarget=1.8 here, as it conflicts with jvmToolchain
+        languageVersion(overriddenLanguageVersion)
     }
 }
 

rules/rules-integration-tests/build.gradle.kts

@@ -26,6 +26,11 @@ plugins {
 kotlin {
     // use toolchain from settings
     jvmToolchain(jdkToolchainVersion)
+    compilerOptions {
+        defaultOptions()
+        // Do not set jvmTarget=1.8 here, as it conflicts with jvmToolchain
+        languageVersion(overriddenLanguageVersion)
+    }
 }
 
 val sharedSourceSet = sourceSets.create("shared") {