* [CallableDescriptor.getOverriddenDescriptors] instead, which is separate from [CallableDescriptor.getOriginal].
 */
@Suppress("UNCHECKED_CAST")
private fun <T : CallableDescriptor> T.unwrapUseSiteSubstitutionOverride(): T {
    var current: CallableDescriptor = this
    while (original != current) {
        current = current.original
    }

     * prefixed with a suitable extension receiver type (like in `Foo.bar`, or `foo.Foo.bar`).
     *
     * Relies on the fact that in such references only the last qualifier refers to the
     * actual extension callable, and the part before that refers to the receiver type (either fully
     * or partially qualified).
     *

                // E.g., coreR.string.hello
                //   -> string.hello (drop the first segment)
                //   test.pkg.R.string.hello
                //   -> string.hello (take last two segments, where the size is determined by the size of qualified access minus 1)
                val fixedQualifiedAccessSegments = qualifiedAccessSegments.drop(1)

        val firValuedReturnExpressions = collector.firReturnExpressions.filter { !it.result.resolvedType.isUnit }

        val defaultStatement = statements.last()
        val firDefaultStatement = firStatements.last()
        val defaultExpressionInfo = computeDefaultExpression(defaultStatement, firDefaultStatement, firValuedReturnExpressions)

        val graphIndex = ControlFlowGraphIndex {

    inline fun <reified S : To> cache(key: From, calculation: () -> S): S {
        val value = cache.getOrPut(key, calculation)
        return value as? S
            ?: errorWithAttachment("Cannot cast ${value::class} to ${S::class}") {
                withEntry("value", value.toString())
            }
    }
}

internal fun FirElement.buildSymbol(builder: KtSymbolByFirBuilder) =

            val dependencyFiles = buildSet {
                addAll(compilationPeerData.files)
                addAll(codeFragmentMappings?.capturedFiles.orEmpty())

                // The main file needs to be the last so caches for the context declarations are populated in FIR-to-IR.
                remove(file)
            }

            addAll(dependencyFiles)
            add(file)
        }

                @Suppress("UNCHECKED_CAST")
                diagnostic.a as Collection<ResolvedCall<*>>
            }
            in diagnosticWithResolvedCallsAtPosition2 -> {
                require(diagnostic is DiagnosticWithParameters2<*, *, *>)
                @Suppress("UNCHECKED_CAST")
                diagnostic.b as Collection<ResolvedCall<*>>
            }

    ): FirLiteralExpression<*>? {
        if (value == null || other.value == null) return null
        // NB: some utils accept very general types, and due to the way operation map works, we should up-cast rhs type.
        val rightType = when {
            function.symbol.callableId.isStringEquals -> CompileTimeType.ANY
            function.symbol.callableId.isStringPlus -> CompileTimeType.ANY

        val expandedType = type.coneType.fullyExpandedType(rootModuleSession)
        return when (this) {
            KtTypeMappingMode.DEFAULT -> TypeMappingMode.DEFAULT
            KtTypeMappingMode.DEFAULT_UAST -> TypeMappingMode.DEFAULT_UAST
            KtTypeMappingMode.GENERIC_ARGUMENT -> TypeMappingMode.GENERIC_ARGUMENT
            KtTypeMappingMode.SUPER_TYPE -> TypeMappingMode.SUPER_TYPE

     * two.
     *
     * Whether an expression is used is defined by the context in which it
     * appears. E.g. a "statement" in a block is considered used if it is the
     * last expression in that block AND the block itself is used -- a
     * recursive call to `isUsed`, one level higher in the syntax tree.
     *
     * The methods are _conservative_, erring on the side of answering `true`.
     */