FIR: Get rid of PSI dependency in the :fir:resolve module

compiler/fir/resolve/build.gradle.kts

@@ -14,10 +14,9 @@ dependencies {
     api(project(":compiler:fir:tree"))
     api(kotlinxCollectionsImmutable())
     implementation(project(":core:util.runtime"))
-    implementation(project(":compiler:psi"))
 
     compileOnly(project(":kotlin-reflect-api"))
-    compileOnly(intellijCoreDep()) { includeJars("intellij-core", "guava", rootProject = rootProject) }
+    compileOnly(intellijCoreDep()) { includeJars("guava", rootProject = rootProject) }
 }
 
 sourceSets {

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/FirQualifiedNameResolver.kt

@@ -19,7 +19,6 @@ import org.jetbrains.kotlin.fir.resolve.typeForQualifier
 import org.jetbrains.kotlin.fir.types.FirTypeProjection
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.Name
-import org.jetbrains.kotlin.psi.psiUtil.parentsWithSelf
 
 const val ROOT_PREFIX_FOR_IDE_RESOLUTION_MODE = "_root_ide_package_"
 
@@ -92,7 +91,7 @@ class FirQualifiedNameResolver(private val components: BodyResolveComponents) {
             }
 
             return buildResolvedQualifier {
-                this.source = getWholeQualifierSource(source, qualifierPartsToDrop)
+                this.source = source?.getWholeQualifierSourceIfPossible(qualifierPartsToDrop)
                 packageFqName = resolved.packageFqName
                 relativeClassFqName = resolved.relativeClassFqName
                 symbol = resolved.classSymbol
@@ -104,12 +103,4 @@ class FirQualifiedNameResolver(private val components: BodyResolveComponents) {
 
         return null
     }
-
-    private fun getWholeQualifierSource(qualifierStartSource: FirSourceElement?, stepsToWholeQualifier: Int): FirSourceElement? {
-        if (qualifierStartSource !is FirRealPsiSourceElement<*>) return qualifierStartSource
-
-        val qualifierStart = qualifierStartSource.psi
-        val wholeQualifier = qualifierStart.parentsWithSelf.drop(stepsToWholeQualifier).first()
-        return wholeQualifier.toFirPsiSourceElement()
-    }
 }

compiler/fir/tree/src/org/jetbrains/kotlin/fir/Utils.kt

@@ -56,3 +56,20 @@ fun <R : FirTypeRef> R.copyWithNewSourceKind(newKind: FirFakeSourceElementKind):
     } as R
 }
 
+/**
+ * Let's take `a.b.c.call()` expression as an example.
+ *
+ * This function allows to transform `SourceElement(psi = 'a')` to `SourceElement(psi = 'a.b.c')`
+ * ([stepsToWholeQualifier] should be = 2 for that).
+ *
+ * @receiver original source element
+ * @param stepsToWholeQualifier distance between the original psi and the whole qualifier psi
+ */
+fun FirSourceElement.getWholeQualifierSourceIfPossible(stepsToWholeQualifier: Int): FirSourceElement {
+    if (this !is FirRealPsiSourceElement<*>) return this
+
+    val qualifiersChain = generateSequence(psi) { it.parent }
+    val wholeQualifier = qualifiersChain.drop(stepsToWholeQualifier).first()
+
+    return wholeQualifier.toFirPsiSourceElement() as FirRealPsiSourceElement
+}