[FIR] Support @LowPriorityInOverloadResolution annotation

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/CallKind.kt

@@ -12,7 +12,8 @@ enum class CallKind(vararg resolutionSequence: ResolutionStage) {
         CheckExplicitReceiverConsistency,
         CreateFreshTypeVariableSubstitutorStage,
         CheckReceivers.Dispatch,
-        CheckReceivers.Extension
+        CheckReceivers.Extension,
+        CheckLowPriorityInOverloadResolution
     ),
     SyntheticSelect(
         MapArguments,
@@ -29,7 +30,8 @@ enum class CallKind(vararg resolutionSequence: ResolutionStage) {
         CheckReceivers.Dispatch,
         CheckReceivers.Extension,
         CheckArguments,
-        EagerResolveOfCallableReferences
+        EagerResolveOfCallableReferences,
+        CheckLowPriorityInOverloadResolution
     ),
     CallableReference(
         CheckVisibility,

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/Candidate.kt

@@ -71,6 +71,7 @@ enum class CandidateApplicability {
     PARAMETER_MAPPING_ERROR,
     INAPPLICABLE,
     SYNTHETIC_RESOLVED,
+    RESOLVED_LOW_PRIORITY,
     RESOLVED
 }
 

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/ResolverParts.kt

@@ -6,6 +6,7 @@
 package org.jetbrains.kotlin.fir.resolve.calls
 
 import org.jetbrains.kotlin.descriptors.Visibilities
+import org.jetbrains.kotlin.fir.FirAnnotationContainer
 import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.expressions.FirExpression
@@ -26,6 +27,7 @@ import org.jetbrains.kotlin.fir.types.*
 import org.jetbrains.kotlin.load.java.JavaVisibilities
 import org.jetbrains.kotlin.name.ClassId
 import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.resolve.calls.inference.ConstraintSystemOperation
 import org.jetbrains.kotlin.resolve.calls.inference.model.SimpleConstraintSystemConstraintPosition
 import org.jetbrains.kotlin.resolve.calls.tasks.ExplicitReceiverKind
@@ -472,3 +474,24 @@ internal object CheckVisibility : CheckerStage() {
         }
     }
 }
+
+internal object CheckLowPriorityInOverloadResolution : CheckerStage() {
+    private val LOW_PRIORITY_IN_OVERLOAD_RESOLUTION_CLASS_ID: ClassId =
+        ClassId(FqName("kotlin.internal"), Name.identifier("LowPriorityInOverloadResolution"))
+
+    override suspend fun check(candidate: Candidate, sink: CheckerSink, callInfo: CallInfo) {
+        val annotations = when (val fir = candidate.symbol.fir) {
+            is FirSimpleFunction -> fir.annotations
+            is FirProperty -> fir.annotations
+            else -> return
+        }
+        val hasLowPriorityAnnotation = annotations.any {
+            val lookupTag = ((it.annotationTypeRef as? FirResolvedTypeRef)?.type as? ConeClassLikeType)?.lookupTag ?: return@any false
+            lookupTag.classId == LOW_PRIORITY_IN_OVERLOAD_RESOLUTION_CLASS_ID
+        }
+
+        if (hasLowPriorityAnnotation) {
+            sink.reportApplicability(CandidateApplicability.RESOLVED_LOW_PRIORITY)
+        }
+    }
+}

compiler/fir/resolve/testData/resolveWithStdlib/lowPriorityInResolution.kt

@@ -0,0 +1,10 @@
+@Suppress("INVISIBLE_MEMBER", "INVISIBLE_REFERENCE")
+@kotlin.internal.LowPriorityInOverloadResolution
+fun foo(): Int = 1
+
+fun foo(): String = ""
+
+fun test() {
+    val s = foo()
+    s.length
+}

compiler/fir/resolve/testData/resolveWithStdlib/lowPriorityInResolution.txt

@@ -0,0 +1,11 @@
+FILE: lowPriorityInResolution.kt
+    @R|kotlin/Suppress|(String(INVISIBLE_MEMBER), String(INVISIBLE_REFERENCE)) @R|kotlin/internal/LowPriorityInOverloadResolution|() public final fun foo(): R|kotlin/Int| {
+        ^foo Int(1)
+    }
+    public final fun foo(): R|kotlin/String| {
+        ^foo String()
+    }
+    public final fun test(): R|kotlin/Unit| {
+        lval s: R|kotlin/String| = R|/foo|()
+        R|<local>/s|.R|kotlin/String.length|
+    }

compiler/fir/resolve/tests/org/jetbrains/kotlin/fir/FirDiagnosticsWithStdlibTestGenerated.java

@@ -163,6 +163,11 @@ public class FirDiagnosticsWithStdlibTestGenerated extends AbstractFirDiagnostic
         runTest("compiler/fir/resolve/testData/resolveWithStdlib/listPlusAssign.kt");
     }
 
+    @TestMetadata("lowPriorityInResolution.kt")
+    public void testLowPriorityInResolution() throws Exception {
+        runTest("compiler/fir/resolve/testData/resolveWithStdlib/lowPriorityInResolution.kt");
+    }
+
     @TestMetadata("mapList.kt")
     public void testMapList() throws Exception {
         runTest("compiler/fir/resolve/testData/resolveWithStdlib/mapList.kt");

compiler/testData/codegen/box/annotations/resolveWithLowPriorityAnnotation.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // WITH_RUNTIME
 
 @Suppress("INVISIBLE_MEMBER", "INVISIBLE_REFERENCE")

compiler/testData/diagnostics/testsWithStdLib/inference/annotationsForResolve/noInferAndLowPriority.fir.kt

@@ -11,6 +11,6 @@ public fun <T> Iterable<T>.contains1(element: @kotlin.internal.NoInfer T): Boole
 
 
 fun test() {
-    val a: Boolean = listOf(1).<!AMBIGUITY!>contains1<!>("")
+    val a: Boolean = listOf(1).contains1("")
-    val b: Boolean = listOf(1).<!AMBIGUITY!>contains1<!>(1)
+    val b: Boolean = listOf(1).contains1(1)
 }

compiler/testData/diagnostics/testsWithStdLib/inference/annotationsForResolve/onlyInputTypesAndLowPriority.fir.kt

@@ -19,8 +19,8 @@ public fun <K, V> Map<K, V>.get1(key: Any?): Int = null!!
 public fun <@kotlin.internal.OnlyInputTypes K, V> Map<out K, V>.get1(key: K): V? = null!!
 
 fun test(map: Map<Int, String>) {
-    val a: Int = listOf(1).<!AMBIGUITY!>contains1<!>("")
+    val a: Int = listOf(1).contains1("")
-    val b: Boolean = listOf(1).<!AMBIGUITY!>contains1<!>(1)
+    val b: Boolean = listOf(1).contains1(1)
 
     val c: String? = map.get1("")
     val d: String? = map.get1(1)