// atomic_casPointer is the implementation of runtime/internal/UnsafePointer.CompareAndSwap
// (like CompareAndSwapNoWB but with the write barrier).
//
//go:nosplit
//go:linkname atomic_casPointer internal/runtime/atomic.casPointer
func atomic_casPointer(ptr *unsafe.Pointer, old, new unsafe.Pointer) bool {
	if writeBarrier.enabled {
		atomicwb(ptr, new)
	}
	if goexperiment.CgoCheck2 {
		cgoCheckPtrWrite(ptr, new)
	}

// and if they're equal, swaps u's value with new.
// It reports whether the swap ran.
func (u *UnsafePointer) CompareAndSwap(old, new unsafe.Pointer) bool {
	return casPointer(&u.value, old, new)
}

func casPointer(ptr *unsafe.Pointer, old, new unsafe.Pointer) bool

// Pointer is an atomic pointer of type *T.
type Pointer[T any] struct {
	u UnsafePointer
}

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

// Helper functions exported for the compiler.
// Do not use internally.

package types2

// If t is a pointer, AsPointer returns that type, otherwise it returns nil.
func AsPointer(t Type) *Pointer {
	u, _ := t.Underlying().(*Pointer)
	return u
}

// If t is a signature, AsSignature returns that type, otherwise it returns nil.
func AsSignature(t Type) *Signature {

		return false
	}

	return p.hasPointer(f, t, true)
}

// hasPointer is used by needsPointerCheck. If top is true it returns
// whether t is or contains a pointer that might point to a pointer.
// If top is false it reports whether t is or contains a pointer.
// f may be nil.
func (p *Package) hasPointer(f *File, t ast.Expr, top bool) bool {
	switch t := t.(type) {

		if gccResult != "void" {
			// Verify that any results don't contain any
			// Go pointers.
			forFieldList(fntype.Results,
				func(i int, aname string, atype ast.Expr) {
					if !p.hasPointer(nil, atype, false) {
						return
					}
					fmt.Fprintf(fgo2, "\t_cgoCheckResult(a.r%d)\n", i)
				})
		}
		fmt.Fprint(fgo2, "}\n")
	}

	fmt.Fprintf(fgcch, "%s", gccExportHeaderEpilog)