[LL] Run LLFirExpectActualMatchingTargetResolver only for KMP projects

Review: https://jetbrains.team/p/kt/reviews/13244

Motivation: Performance. When I fix KT-59887 in later commits, I will
make actual-to-expect resolve to work not only for actual declarations.
Considering that LLFirExpectActualMatcherLazyResolver worked even for
non-KMP projects that might be a potential performance regression

FirExpectActualMatcherProcessor in the compiler does the same thing (it
checks for MultiPlatformProjects before running the transformer)

analysis/low-level-api-fir/src/org/jetbrains/kotlin/analysis/low/level/api/fir/transformers/LLFirExpectActualMatcherLazyResolver.kt

@@ -8,10 +8,12 @@ package org.jetbrains.kotlin.analysis.low.level.api.fir.transformers
 import org.jetbrains.kotlin.analysis.low.level.api.fir.api.targets.LLFirResolveTarget
 import org.jetbrains.kotlin.analysis.low.level.api.fir.file.builder.LLFirLockProvider
 import org.jetbrains.kotlin.analysis.low.level.api.fir.util.checkExpectForActualIsResolved
+import org.jetbrains.kotlin.config.LanguageFeature
 import org.jetbrains.kotlin.fir.FirElementWithResolveState
 import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.expressions.FirStatement
+import org.jetbrains.kotlin.fir.languageVersionSettings
 import org.jetbrains.kotlin.fir.resolve.ScopeSession
 import org.jetbrains.kotlin.fir.resolve.transformers.body.resolve.FirResolveContextCollector
 import org.jetbrains.kotlin.fir.resolve.transformers.mpp.FirExpectActualMatcherTransformer
@@ -29,8 +31,12 @@ internal object LLFirExpectActualMatcherLazyResolver : LLFirLazyResolver(FirReso
     }
 
     override fun phaseSpecificCheckIsResolved(target: FirElementWithResolveState) {
-        if (target !is FirMemberDeclaration || !target.canHaveExpectCounterPart()) return
+        if (target.moduleData.session.languageVersionSettings.supportsFeature(LanguageFeature.MultiPlatformProjects) &&
-        checkExpectForActualIsResolved(target)
+            target is FirMemberDeclaration &&
+            target.canHaveExpectCounterPart()
+        ) {
+            checkExpectForActualIsResolved(target)
+        }
     }
 }
 
@@ -40,6 +46,8 @@ private class LLFirExpectActualMatchingTargetResolver(
     session: FirSession,
     scopeSession: ScopeSession,
 ) : LLFirTargetResolver(target, lockProvider, FirResolvePhase.EXPECT_ACTUAL_MATCHING) {
+    private val enabled = session.languageVersionSettings.supportsFeature(LanguageFeature.MultiPlatformProjects)
+
     private val transformer = object : FirExpectActualMatcherTransformer(session, scopeSession) {
         override fun transformRegularClass(regularClass: FirRegularClass, data: Nothing?): FirStatement {
             transformMemberDeclaration(regularClass)
@@ -48,9 +56,9 @@ private class LLFirExpectActualMatchingTargetResolver(
     }
 
     override fun doLazyResolveUnderLock(target: FirElementWithResolveState) {
-        if (target !is FirMemberDeclaration) return
+        if (enabled && target is FirMemberDeclaration && target.canHaveExpectCounterPart()) {
-        if (!target.canHaveExpectCounterPart()) return
+            transformer.transformMemberDeclaration(target)
-        transformer.transformMemberDeclaration(target)
+        }
     }
 }
 

analysis/low-level-api-fir/testData/getOrBuildFir/invalidCode/expectAndActualInTheSameFile.txt

@@ -10,6 +10,6 @@ FILE: [ResolvedTo(IMPORTS)] expectAndActualInTheSameFile.kt
     public? final? [ResolvedTo(RAW_FIR)] fun main(): R|kotlin/Unit| { LAZY_BLOCK }
     public? final? expect [ResolvedTo(RAW_FIR)] fun f(): R|kotlin/Unit|
     public? final? [ResolvedTo(RAW_FIR)] fun test(): R|kotlin/Unit| { LAZY_BLOCK }
-    public final actual [ResolvedTo(BODY_RESOLVE)] [ExpectForActualAttributeKey={}] fun f(): R|kotlin/Unit| {
+    public final actual [ResolvedTo(BODY_RESOLVE)] fun f(): R|kotlin/Unit| {
         <Unresolved name: println>#(String(Hello))
     }

analysis/low-level-api-fir/testData/lazyResolve/classes/actual.txt

@@ -161,7 +161,7 @@ FILE: [ResolvedTo(IMPORTS)] actual.kt
 
 EXPECT_ACTUAL_MATCHING:
 FILE: [ResolvedTo(IMPORTS)] actual.kt
-    public final actual [ResolvedTo(EXPECT_ACTUAL_MATCHING)] [ExpectForActualAttributeKey={}] class Actual : R|kotlin/Any| {
+    public final actual [ResolvedTo(EXPECT_ACTUAL_MATCHING)] class Actual : R|kotlin/Any| {
         public? [ResolvedTo(RAW_FIR)] [ContainingClassKey=Actual] constructor(): R|Actual| {
             LAZY_super<R|kotlin/Any|>
         }
@@ -184,7 +184,7 @@ FILE: [ResolvedTo(IMPORTS)] actual.kt
 
 CONTRACTS:
 FILE: [ResolvedTo(IMPORTS)] actual.kt
-    public final actual [ResolvedTo(CONTRACTS)] [ExpectForActualAttributeKey={}] class Actual : R|kotlin/Any| {
+    public final actual [ResolvedTo(CONTRACTS)] class Actual : R|kotlin/Any| {
         public? [ResolvedTo(RAW_FIR)] [ContainingClassKey=Actual] constructor(): R|Actual| {
             LAZY_super<R|kotlin/Any|>
         }
@@ -207,7 +207,7 @@ FILE: [ResolvedTo(IMPORTS)] actual.kt
 
 IMPLICIT_TYPES_BODY_RESOLVE:
 FILE: [ResolvedTo(IMPORTS)] actual.kt
-    public final actual [ResolvedTo(IMPLICIT_TYPES_BODY_RESOLVE)] [ExpectForActualAttributeKey={}] class Actual : R|kotlin/Any| {
+    public final actual [ResolvedTo(IMPLICIT_TYPES_BODY_RESOLVE)] class Actual : R|kotlin/Any| {
         public? [ResolvedTo(RAW_FIR)] [ContainingClassKey=Actual] constructor(): R|Actual| {
             LAZY_super<R|kotlin/Any|>
         }
@@ -230,7 +230,7 @@ FILE: [ResolvedTo(IMPORTS)] actual.kt
 
 ANNOTATION_ARGUMENTS:
 FILE: [ResolvedTo(IMPORTS)] actual.kt
-    public final actual [ResolvedTo(ANNOTATION_ARGUMENTS)] [ExpectForActualAttributeKey={}] class Actual : R|kotlin/Any| {
+    public final actual [ResolvedTo(ANNOTATION_ARGUMENTS)] class Actual : R|kotlin/Any| {
         public? [ResolvedTo(RAW_FIR)] [ContainingClassKey=Actual] constructor(): R|Actual| {
             LAZY_super<R|kotlin/Any|>
         }
@@ -253,7 +253,7 @@ FILE: [ResolvedTo(IMPORTS)] actual.kt
 
 BODY_RESOLVE:
 FILE: [ResolvedTo(IMPORTS)] actual.kt
-    public final actual [ResolvedTo(BODY_RESOLVE)] [ExpectForActualAttributeKey={}] class Actual : R|kotlin/Any| {
+    public final actual [ResolvedTo(BODY_RESOLVE)] class Actual : R|kotlin/Any| {
         public [ResolvedTo(BODY_RESOLVE)] [ContainingClassKey=Actual] constructor(): R|Actual| {
             super<R|kotlin/Any|>()
         }
@@ -276,7 +276,7 @@ FILE: [ResolvedTo(IMPORTS)] actual.kt
 
 FILE RAW TO BODY:
 FILE: [ResolvedTo(BODY_RESOLVE)] actual.kt
-    public final actual [ResolvedTo(BODY_RESOLVE)] [ExpectForActualAttributeKey={}] class Actual : R|kotlin/Any| {
+    public final actual [ResolvedTo(BODY_RESOLVE)] class Actual : R|kotlin/Any| {
         public [ResolvedTo(BODY_RESOLVE)] [ContainingClassKey=Actual] constructor(): R|Actual| {
             super<R|kotlin/Any|>()
         }
@@ -287,7 +287,7 @@ FILE: [ResolvedTo(BODY_RESOLVE)] actual.kt
         public final [ResolvedTo(BODY_RESOLVE)] val a: R|kotlin/Int| = Int(1)
             public [ResolvedTo(BODY_RESOLVE)] [ContainingClassKey=Actual] get(): R|kotlin/Int|
 
-        public final actual [ResolvedTo(BODY_RESOLVE)] [ExpectForActualAttributeKey={}] class NestedActual : R|kotlin/Any| {
+        public final actual [ResolvedTo(BODY_RESOLVE)] class NestedActual : R|kotlin/Any| {
             public [ResolvedTo(BODY_RESOLVE)] [ContainingClassKey=NestedActual] constructor(): R|Actual.NestedActual| {
                 super<R|kotlin/Any|>()
             }