From fe2251bfcaff013cc4780f9d6f52a9cea9380c04 Mon Sep 17 00:00:00 2001
From: Alexander Udalov <Alexander.Udalov@jetbrains.com>
Date: Thu, 2 Aug 2018 17:36:43 +0200
Subject: [PATCH] Run classifier usage checkers on function types

---
 .../checkers/ClassifierUsageChecker.kt        | 23 +++++++++++++++----
 .../sourceCompatibility/noBigFunctionTypes.kt |  5 +++-
 .../noBigFunctionTypes.txt                    |  2 +-
 3 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/ClassifierUsageChecker.kt b/compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/ClassifierUsageChecker.kt
index 421c10ae65a..530f425afcb 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/ClassifierUsageChecker.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/ClassifierUsageChecker.kt
@@ -18,11 +18,12 @@ package org.jetbrains.kotlin.resolve.checkers
 
 import com.intellij.psi.PsiElement
 import org.jetbrains.kotlin.config.LanguageVersionSettings
-import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.descriptors.ClassConstructorDescriptor
+import org.jetbrains.kotlin.descriptors.ClassifierDescriptor
+import org.jetbrains.kotlin.descriptors.DeclarationDescriptorWithSource
+import org.jetbrains.kotlin.descriptors.ModuleDescriptor
 import org.jetbrains.kotlin.lexer.KtTokens
-import org.jetbrains.kotlin.psi.KtNameReferenceExpression
-import org.jetbrains.kotlin.psi.KtReferenceExpression
-import org.jetbrains.kotlin.psi.KtTreeVisitorVoid
+import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.BindingTrace
 import org.jetbrains.kotlin.resolve.DeprecationResolver
@@ -62,7 +63,19 @@ fun checkClassifierUsages(
             }
         }
 
-        private fun runCheckersWithTarget(target: ClassifierDescriptor, expression: KtReferenceExpression) {
+        override fun visitFunctionType(type: KtFunctionType) {
+            super.visitFunctionType(type)
+
+            val kotlinType = context.trace.get(BindingContext.TYPE, type.parent as? KtTypeReference ?: return)
+            if (kotlinType != null) {
+                val descriptor = kotlinType.constructor.declarationDescriptor
+                if (descriptor is ClassifierDescriptor) {
+                    runCheckersWithTarget(descriptor, type)
+                }
+            }
+        }
+
+        private fun runCheckersWithTarget(target: ClassifierDescriptor, expression: KtElement) {
             for (checker in checkers) {
                 checker.check(target, expression, context)
             }
diff --git a/compiler/testData/diagnostics/tests/sourceCompatibility/noBigFunctionTypes.kt b/compiler/testData/diagnostics/tests/sourceCompatibility/noBigFunctionTypes.kt
index 3495385462a..f313b667d52 100644
--- a/compiler/testData/diagnostics/tests/sourceCompatibility/noBigFunctionTypes.kt
+++ b/compiler/testData/diagnostics/tests/sourceCompatibility/noBigFunctionTypes.kt
@@ -11,7 +11,10 @@ fun foo(
 
 fun bar(x: Any) {}
 
-fun test(vararg x: <!UNSUPPORTED_FEATURE!>Function30<!><*, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, Unit>) {
+fun test(
+    w: <!UNSUPPORTED_FEATURE!>(A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A) -> Unit<!>,
+    vararg x: <!UNSUPPORTED_FEATURE!>Function30<!><*, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, Unit>
+) {
     bar(<!UNSUPPORTED_FEATURE!>::foo<!>)
     bar(x)
 }
diff --git a/compiler/testData/diagnostics/tests/sourceCompatibility/noBigFunctionTypes.txt b/compiler/testData/diagnostics/tests/sourceCompatibility/noBigFunctionTypes.txt
index 68ed64937d3..d50418dde5c 100644
--- a/compiler/testData/diagnostics/tests/sourceCompatibility/noBigFunctionTypes.txt
+++ b/compiler/testData/diagnostics/tests/sourceCompatibility/noBigFunctionTypes.txt
@@ -2,7 +2,7 @@ package
 
 public fun bar(/*0*/ x: kotlin.Any): kotlin.Unit
 public fun foo(/*0*/ p00: A, /*1*/ p01: A, /*2*/ p02: A, /*3*/ p03: A, /*4*/ p04: A, /*5*/ p05: A, /*6*/ p06: A, /*7*/ p07: A, /*8*/ p08: A, /*9*/ p09: A, /*10*/ p10: A, /*11*/ p11: A, /*12*/ p12: A, /*13*/ p13: A, /*14*/ p14: A, /*15*/ p15: A, /*16*/ p16: A, /*17*/ p17: A, /*18*/ p18: A, /*19*/ p19: A, /*20*/ p20: A, /*21*/ p21: A, /*22*/ p22: A, /*23*/ p23: A, /*24*/ p24: A, /*25*/ p25: A, /*26*/ p26: A, /*27*/ p27: A, /*28*/ p28: A, /*29*/ p29: A): kotlin.Unit
-public fun test(/*0*/ vararg x: kotlin.Function30<*, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, kotlin.Unit> /*kotlin.Array<out kotlin.Function30<*, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, kotlin.Unit>>*/): kotlin.Unit
+public fun test(/*0*/ w: (A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A) -> kotlin.Unit, /*1*/ vararg x: kotlin.Function30<*, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, kotlin.Unit> /*kotlin.Array<out kotlin.Function30<*, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, *, kotlin.Unit>>*/): kotlin.Unit
 
 public final class A {
     public constructor A()