[FIR] Add opt-in annotation which prevents from using symbol.fir

compiler/fir/build.gradle.kts

@@ -0,0 +1,26 @@
+val projectsAllowedToUseFirFromSymbol = listOf(
+    "analysis-tests",
+    "dump",
+    "fir-deserialization",
+    "fir-serialization",
+    "fir2ir",
+    "java",
+    "jvm",
+    "raw-fir",
+    "resolve",
+    "tree",
+    "jvm-backend",
+    "light-tree2fir",
+    "psi2fir",
+    "raw-fir.common"
+)
+
+subprojects {
+    if (name in projectsAllowedToUseFirFromSymbol) {
+        tasks.withType<org.jetbrains.kotlin.gradle.dsl.KotlinCompile<*>> {
+            kotlinOptions {
+                freeCompilerArgs += "-Xopt-in=org.jetbrains.kotlin.fir.symbols.SymbolInternals"
+            }
+        }
+    }
+}

compiler/fir/tree/src/org/jetbrains/kotlin/fir/symbols/FirBasedSymbol.kt

@@ -13,6 +13,7 @@ import org.jetbrains.kotlin.fir.declarations.FirDeclarationOrigin
 abstract class FirBasedSymbol<E : FirDeclaration> {
     private var _fir: E? = null
 
+    @SymbolInternals
     val fir: E
         get() = _fir
             ?: error("Fir is not initialized for $this")
@@ -30,3 +31,6 @@ abstract class FirBasedSymbol<E : FirDeclaration> {
     val moduleData: FirModuleData
         get() = fir.moduleData
 }
+
+@RequiresOptIn
+annotation class SymbolInternals

compiler/visualizer/render-fir/build.gradle.kts

@@ -14,3 +14,9 @@ sourceSets {
     "main" { projectDefault() }
     "test" { }
 }
+
+tasks.withType<org.jetbrains.kotlin.gradle.dsl.KotlinCompile<*>> {
+    kotlinOptions {
+        freeCompilerArgs += "-Xopt-in=org.jetbrains.kotlin.fir.symbols.SymbolInternals"
+    }
+}

idea/idea-frontend-fir/build.gradle.kts

@@ -62,6 +62,13 @@ projectTest(jUnit5Enabled = true) {
 
 testsJar()
 
+allprojects {
+    tasks.withType<org.jetbrains.kotlin.gradle.dsl.KotlinCompile<*>> {
+        kotlinOptions {
+            freeCompilerArgs += "-Xopt-in=org.jetbrains.kotlin.fir.symbols.SymbolInternals"
+        }
+    }
+}
 
 val generatorClasspath by configurations.creating
 

settings.gradle

@@ -262,7 +262,8 @@ include ":benchmarks",
         ":wasm:wasm.ir"
 
 
-include ":compiler:fir:cones",
+include ":compiler:fir",
+        ":compiler:fir:cones",
         ":compiler:fir:tree",
         ":compiler:fir:tree:tree-generator",
         ":compiler:fir:raw-fir:raw-fir.common",