// license that can be found in the LICENSE file.

package runtime

import "internal/abi"

// isDirectIface reports whether t is stored directly in an interface value.
func isDirectIface(t *_type) bool {
	return t.Kind_&abi.KindDirectIface != 0

// A typeSwitch walks a type switch.
type typeSwitch struct {
	// Temporary variables (i.e., ONAMEs) used by type switch dispatch logic:
	srcName  ir.Node // value being type-switched on
	hashName ir.Node // type hash of the value being type-switched on
	okName   ir.Node // boolean used for comma-ok type assertions
	itabName ir.Node // itab value to use for first word of non-empty interface
}

type typeClause struct {
	hash uint32

import (
	"unsafe"
)

const raceenabled = false

// Because raceenabled is false, none of these functions should be called.

func raceReadObjectPC(t *_type, addr unsafe.Pointer, callerpc, pc uintptr)  { throw("race") }
func raceWriteObjectPC(t *_type, addr unsafe.Pointer, callerpc, pc uintptr) { throw("race") }
func raceinit() (uintptr, uintptr)                                          { throw("race"); return 0, 0 }

// wbMove performs the write barrier operations necessary before
// copying a region of memory from src to dst of type typ.
// Does not actually do the copying.
//
//go:nowritebarrierrec
//go:nosplit
func wbMove(typ *_type, dst, src unsafe.Pointer) {
	// This always copies a full value of type typ so it's safe to
	// pass a type here.
	//
	// See the comment on bulkBarrierPreWrite.

	// a pointer/scalar bitmap. We also reserve space for a dummy _type that
	// refers to the bitmap. The PtrBytes field of the dummy _type indicates how
	// many of those bits are valid.
	return userArenaChunkBytes/goarch.PtrSize/8 + unsafe.Sizeof(_type{})
}

type userArena struct {
	// full is a list of full chunks that have not enough free memory left, and

			// Allocate space to unroll the gcprog. This space will consist of
			// a dummy _type value and the unrolled gcprog. The dummy _type will
			// refer to the bitmap, and the mspan will refer to the dummy _type.
			if span.spanclass.sizeclass() != 0 {
				throw("GCProg for type that isn't large")
			}
			spaceNeeded := alignUp(unsafe.Sizeof(_type{}), goarch.PtrSize)
			heapBitsOff := spaceNeeded

		config = &defaultConfig
	}

	x, xType, ok := functionAndType(f)
	if !ok {
		return SetupError("f is not a function")
	}
	y, yType, ok := functionAndType(g)
	if !ok {
		return SetupError("g is not a function")
	}

	if xType != yType {
		return SetupError("functions have different types")
	}

	arguments := make([]reflect.Value, xType.NumIn())
	rand := config.getRand()

func (p *Package) writeDefsFunc(fgo2 io.Writer, n *Name, callsMalloc *bool) {
	name := n.Go
	gtype := n.FuncType.Go
	void := gtype.Results == nil || len(gtype.Results.List) == 0
	if n.AddError {
		// Add "error" to return type list.
		// Type list is known to be 0 or 1 element - it's a C function.
		err := &ast.Field{Type: ast.NewIdent("error")}
		l := gtype.Results.List
		if len(l) == 0 {
			l = []*ast.Field{err}
		} else {

		// collect generic receiver type parameters, if any
		// - a receiver type parameter is like any other type parameter, except that it is declared implicitly
		// - the receiver specification acts as local declaration for its type parameters, which may be blank
		_, rname, rparams := check.unpackRecv(recvPar.List[0].Type, true)
		if len(rparams) > 0 {
			// The scope of the type parameter T in "func (r T[T]) f()"

// have been serialized so far, most recently used first.
// Note: when a bucket overflows we may end up
// serializing a type more than once. That's ok.
const (
	typeCacheBuckets = 256
	typeCacheAssoc   = 4
)

type typeCacheBucket struct {
	t [typeCacheAssoc]*_type
}

var typecache [typeCacheBuckets]typeCacheBucket

// dump a uint64 in a varint format parseable by encoding/binary.