//go:build unix

// Socket control messages

package syscall

import (
	"unsafe"
)

// CmsgLen returns the value to store in the Len field of the [Cmsghdr]
// structure, taking into account any necessary alignment.
func CmsgLen(datalen int) int {
	return cmsgAlignOf(SizeofCmsghdr) + datalen
}

// CmsgSpace returns the number of bytes an ancillary element with
// payload of the passed data length occupies.

	pad   [cpu.CacheLinePadSize - 4]byte
}

//go:noescape
func spinLock(state *uint32)

//go:noescape
func spinUnlock(state *uint32)

//go:nosplit
func lockAndCheck(addr *uint64) {
	// ensure 8-byte alignment
	if uintptr(unsafe.Pointer(addr))&7 != 0 {
		panicUnaligned()
	}
	// force dereference before taking lock
	_ = *addr

	spinLock(&lock.state)
}

//go:nosplit
func unlock() {

func init() {
	// TODO(mdempsky): Push into types.InitUniverse or typecheck.InitUniverse.
	types.PtrSize = 8
	types.RegSize = 8
	types.MaxWidth = 1 << 50

	base.Ctxt = &obj.Link{Arch: &obj.LinkArch{Arch: &sys.Arch{Alignment: 1, CanMergeLoads: true}}}
	typecheck.InitUniverse()
	testTypes.SetTypPtrs()

TEXT runtime·asmstdcall_trampoline<ABIInternal>(SB),NOSPLIT,$0
	MOVQ	AX, CX
	JMP	runtime·asmstdcall(SB)

// void runtime·asmstdcall(void *c);
TEXT runtime·asmstdcall(SB),NOSPLIT,$16
	MOVQ	SP, AX
	ANDQ	$~15, SP	// alignment as per Windows requirement
	MOVQ	AX, 8(SP)
	MOVQ	CX, 0(SP)	// asmcgocall will put first argument into CX.

	MOVQ	libcall_fn(CX), AX
	MOVQ	libcall_args(CX), SI
	MOVQ	libcall_n(CX), CX

	// SetLastError(0).

That said, if you have questions, reach out to us
[one way or another][communication].

[announcement]: https://cncf.io/news/announcement/2015/07/new-cloud-native-computing-foundation-drive-alignment-among-container
[Borg]: https://research.google.com/pubs/pub43438.html
[CNCF]: https://www.cncf.io/about
[communication]: https://git.k8s.io/community/communication
[community repository]: https://git.k8s.io/community

	case *ast.BinaryExpr:
		// "It is valid both to add and to subtract offsets from a
		// pointer in this way. It is also valid to use &^ to round
		// pointers, usually for alignment."
		switch x.Op {
		case token.ADD, token.SUB, token.AND_NOT:
			// TODO(mdempsky): Match compiler
			// semantics. ADD allows a pointer on either
			// side; SUB and AND_NOT don't care about RHS.

// cgo uses -Werror. See #65290.
#pragma GCC diagnostic ignored "-Wpragmas"
#pragma GCC diagnostic ignored "-Wunknown-warning-option"
#pragma GCC diagnostic ignored "-Watomic-alignment"

#include <pthread.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h> // strerror
#include <time.h>
#include "libcgo.h"
#include "libcgo_unix.h"

# There are two ways for the module author to bring the two into alignment.
# One is to *explicitly* 'exclude' the version that is already *implicitly*
# pruned out under 1.17.

go mod edit -exclude=example.com/retract/incompatible@v2.0.0+incompatible
go list -f $MODFMT -deps ./...

		// access to routing facilities.
		salign = 8
	} else if runtime.GOOS == "freebsd" {
		// In the case of kern.supported_archs="amd64 i386",
		// we need to know the underlying kernel's
		// architecture because the alignment for routing
		// facilities are set at the build time of the kernel.
		if freebsdConfArch == "amd64" {
			salign = 8
		}
	}
	if salen == 0 {
		return salign
	}
	return (salen + salign - 1) & ^(salign - 1)

	// instead of failing silently.

	if unsafe.Sizeof(int(0)) != 4 {
		t.Skip("test only runs on 32-bit systems")
	}

	x := make([]uint32, 4)
	u := unsafe.Pointer(uintptr(unsafe.Pointer(&x[0])) | 4) // force alignment to 4

	up64 := (*uint64)(u) // misaligned
	p64 := (*int64)(u)   // misaligned

	shouldPanic(t, "Load64", func() { atomic.Load64(up64) })
	shouldPanic(t, "Loadint64", func() { atomic.Loadint64(p64) })