Introduce repo settings conventions

First convention is to configure Gradle build cache.

buildSrc/settings.gradle

@@ -1,6 +1,13 @@
+import org.gradle.api.internal.GradleInternal
+
 pluginManagement {
     apply from: '../repo/scripts/cache-redirector.settings.gradle.kts'
     apply from: '../repo/scripts/kotlin-bootstrap.settings.gradle.kts'
+
+    if (((GradleInternal) gradle).isRootBuild()) {
+        includeBuild '../repo/gradle-settings-conventions'
+    }
+
     repositories {
         maven { url "https://maven.pkg.jetbrains.space/kotlin/p/kotlin/kotlin-dependencies" }
         mavenCentral()
@@ -8,6 +15,10 @@ pluginManagement {
     }
 }
 
+plugins {
+    id "build-cache"
+}
+
 File versionPropertiesFile = new File(rootProject.projectDir.parentFile, "gradle/versions.properties")
 def versionProperties = new Properties()
 versionPropertiesFile.withInputStream {
@@ -30,16 +41,4 @@ dependencyResolutionManagement {
     }
 }
 
-buildscript {
-    repositories {
-        maven { url "https://maven.pkg.jetbrains.space/kotlin/p/kotlin/kotlin-dependencies" }
-        mavenCentral()
-    }
-
-    def buildGradlePluginVersion = ext["kotlin.build.gradlePlugin.version"]
-    dependencies {
-        classpath("org.jetbrains.kotlin:kotlin-build-gradle-plugin:$buildGradlePluginVersion")
-    }
-}
-
 include "prepare-deps"

repo/gradle-settings-conventions/Readme.md

@@ -0,0 +1,7 @@
+## Description
+
+Provides common settings convention plugins for the repo.
+
+### List of plugins
+
+- "build-cache" - local and remote build cache configuration

repo/gradle-settings-conventions/build-cache/build.gradle.kts

@@ -0,0 +1,16 @@
+plugins {
+    `kotlin-dsl`
+    id("org.jetbrains.kotlin.jvm")
+}
+
+repositories {
+    maven(url = "https://maven.pkg.jetbrains.space/kotlin/p/kotlin/kotlin-dependencies")
+    mavenCentral()
+}
+
+kotlin.jvmToolchain(8)
+
+val buildGradlePluginVersion = extra.get("kotlin.build.gradlePlugin.version")
+dependencies {
+    implementation("org.jetbrains.kotlin:kotlin-build-gradle-plugin:$buildGradlePluginVersion")
+}

repo/gradle-settings-conventions/build-cache/src/main/kotlin/build-cache.settings.gradle.kts

@@ -0,0 +1,24 @@
+val buildProperties = getKotlinBuildPropertiesForSettings(settings)
+
+buildCache {
+    local {
+        isEnabled = buildProperties.localBuildCacheEnabled
+        if (buildProperties.localBuildCacheDirectory != null) {
+            directory = buildProperties.localBuildCacheDirectory
+        }
+    }
+
+    val remoteBuildCacheUrl = buildProperties.buildCacheUrl
+    if (remoteBuildCacheUrl != null) {
+        remote<HttpBuildCache> {
+            url = uri(remoteBuildCacheUrl)
+            isPush = buildProperties.pushToBuildCache
+            if (buildProperties.buildCacheUser != null &&
+                buildProperties.buildCachePassword != null
+            ) {
+                credentials.username = buildProperties.buildCacheUser
+                credentials.password = buildProperties.buildCachePassword
+            }
+        }
+    }
+}

repo/gradle-settings-conventions/gradle.properties

@@ -0,0 +1,3 @@
+kotlin.build.gradlePlugin.version=0.0.39
+kotlin.options.suppressFreeCompilerArgsModificationWarning=true
+cacheRedirectorEnabled=true

repo/gradle-settings-conventions/settings.gradle.kts

@@ -0,0 +1,52 @@
+pluginManagement {
+    apply(from = "../scripts/cache-redirector.settings.gradle.kts")
+    apply(from = "../scripts/kotlin-bootstrap.settings.gradle.kts")
+
+    repositories {
+        maven(url = "https://maven.pkg.jetbrains.space/kotlin/p/kotlin/kotlin-dependencies")
+        mavenCentral()
+        gradlePluginPortal()
+    }
+}
+
+buildscript {
+    repositories {
+        maven(url = "https://maven.pkg.jetbrains.space/kotlin/p/kotlin/kotlin-dependencies")
+        mavenCentral()
+    }
+
+    val buildGradlePluginVersion = extra.get("kotlin.build.gradlePlugin.version")
+    dependencies {
+        classpath("org.jetbrains.kotlin:kotlin-build-gradle-plugin:$buildGradlePluginVersion")
+    }
+}
+
+include(":build-cache")
+
+// Unfortunately it is not possible to apply build-cache.settings.gradle.kts as script compilation
+// could not then find types from "kotlin-build-gradle-plugin"
+// Sync below to the content of settings plugin
+val buildProperties = getKotlinBuildPropertiesForSettings(settings)
+
+buildCache {
+    local {
+        isEnabled = buildProperties.localBuildCacheEnabled
+        if (buildProperties.localBuildCacheDirectory != null) {
+            directory = buildProperties.localBuildCacheDirectory
+        }
+    }
+
+    val remoteBuildCacheUrl = buildProperties.buildCacheUrl
+    if (remoteBuildCacheUrl != null) {
+        remote<HttpBuildCache> {
+            url = uri(remoteBuildCacheUrl)
+            isPush = buildProperties.pushToBuildCache
+            if (buildProperties.buildCacheUser != null &&
+                buildProperties.buildCachePassword != null
+            ) {
+                credentials.username = buildProperties.buildCacheUser
+                credentials.password = buildProperties.buildCachePassword
+            }
+        }
+    }
+}

repo/scripts/kotlin-bootstrap.settings.gradle.kts

@@ -58,12 +58,19 @@ fun getRootSettings(
     // Gradle interface neither exposes flag if it is a root of composite-build hierarchy
     // nor gives access to Settings object. Fortunately it is availaibe inside GradleInternal internal api
     // used by build scan plugin.
+    //
+    // Included builds for build logic are evaluated earlier then root settings leading to error that root settings object is not yet
+    // available. For such cases we fallback to included build settings object and later manual mapping for kotlinRootDir
     val gradleInternal = (gradle as GradleInternal)
-    return if (gradleInternal.isRootBuild()) {
-        settings
-    } else {
-        val gradleParent = gradle.parent ?: error("Could not get includedBuild parent build for ${settings.rootDir}!")
-        getRootSettings(gradle.parent!!.settings, gradle.parent!!)
+    return when {
+        gradleInternal.isRootBuild() ||
+                settings.rootProject.name == "gradle-settings-conventions" -> {
+            settings
+        }
+        else -> {
+            val gradleParent = gradle.parent ?: error("Could not get includedBuild parent build for ${settings.rootDir}!")
+            getRootSettings(gradle.parent!!.settings, gradle.parent!!)
+        }
     }
 }
 
@@ -83,6 +90,7 @@ val kotlinRootDir: File = when (rootSettings.rootProject.name) {
         }
     }
     "benchmarksAnalyzer", "performance-server" -> rootSettings.rootDir.parentFile.parentFile.parentFile
+    "gradle-settings-conventions" -> rootSettings.rootDir.parentFile.parentFile
     "performance" -> rootSettings.rootDir.parentFile.parentFile
     "ui" -> rootSettings.rootDir.parentFile.parentFile.parentFile.parentFile
     else -> rootSettings.rootDir

settings.gradle

@@ -1,4 +1,6 @@
 pluginManagement {
+    includeBuild("repo/gradle-settings-conventions")
+
     apply from: 'repo/scripts/cache-redirector.settings.gradle.kts'
     apply from: 'repo/scripts/kotlin-bootstrap.settings.gradle.kts'
 
@@ -13,17 +15,11 @@ pluginManagement {
     }
 }
 
-buildscript {
-    def buildGradlePluginVersion = ext["kotlin.build.gradlePlugin.version"]
-    dependencies {
-        classpath("org.jetbrains.kotlin:kotlin-build-gradle-plugin:${buildGradlePluginVersion}")
-    }
-}
-
 plugins {
     id "com.gradle.enterprise" version "3.11.2"
     id "com.gradle.common-custom-user-data-gradle-plugin" version "1.8.1" apply false
     id "org.gradle.toolchains.foojay-resolver-convention" version "0.4.0"
+    id "build-cache"
 }
 
 def buildProperties = BuildPropertiesKt.getKotlinBuildPropertiesForSettings(settings)
@@ -54,26 +50,6 @@ gradleEnterprise {
     }
 }
 
-buildCache {
-    local {
-        enabled = buildProperties.localBuildCacheEnabled
-        if (buildProperties.localBuildCacheDirectory != null) {
-            directory = buildProperties.localBuildCacheDirectory
-        }
-    }
-
-    if (buildProperties.buildCacheUrl != null) {
-        remote(HttpBuildCache) {
-            url = buildProperties.buildCacheUrl
-            push = buildProperties.pushToBuildCache
-            if (buildProperties.buildCacheUser != null && buildProperties.buildCachePassword != null) {
-                credentials.username = buildProperties.buildCacheUser
-                credentials.password = buildProperties.buildCachePassword
-            }
-        }
-    }
-}
-
 // modules
 include ":benchmarks",
         ":compiler",