"fmt"
	"go/ast"
	"go/constant"
	"go/token"
	. "internal/types/errors"
)

// An operandMode specifies the (addressing) mode of an operand.
type operandMode byte

const (
	invalid   operandMode = iota // operand is invalid
	novalue                      // operand represents no value (result of a function call w/o result)
	builtin                      // operand is a built-in function

// BUG(r): There is no mechanism for full case folding, that is, for
// characters that involve multiple runes in the input or output.

// Indices into the Delta arrays inside CaseRanges for case mapping.
const (
	UpperCase = iota
	LowerCase
	TitleCase
	MaxCase
)

type d [MaxCase]rune // to make the CaseRanges text shorter

// If the Delta field of a [CaseRange] is UpperLower, it means

	pos := p.expect(keyword)
	var lparen, rparen token.Pos
	var list []ast.Spec
	if p.tok == token.LPAREN {
		lparen = p.pos
		p.next()
		for iota := 0; p.tok != token.RPAREN && p.tok != token.EOF; iota++ {
			list = append(list, f(p.leadComment, keyword, iota))
		}
		rparen = p.expect(token.RPAREN)
		p.expectSemi()
	} else {
		list = append(list, f(nil, keyword, 0))
	}

	return &ast.GenDecl{

	// _Gscanwaiting -> _Gscanrunnable are actually okay because
	// they don't affect stack ownership.

	// _Gidle means this goroutine was just allocated and has not
	// yet been initialized.
	_Gidle = iota // 0

	// _Grunnable means this goroutine is on a run queue. It is
	// not currently executing user code. The stack is not owned.
	_Grunnable // 1

	// _Grunning means this goroutine may execute user code. The

	// i.e. struct fields and array elements, even with non-constant
	// indices: x is non-nil iff x.a.b[i].c is.

	type walkState int
	const (
		Work     walkState = iota // process nil checks and traverse to dominees
		ClearPtr                  // forget the fact that ptr is nil
	)

	type bp struct {
		block *Block // block, or nil in ClearPtr state

// the interface value instead of requiring an allocation.

// A Reg is a single register.
// The zero Reg value has no name but indicates “no register.”
type Reg uint8

const (
	_ Reg = iota

	// 8-bit
	AL
	CL
	DL
	BL
	AH
	CH
	DH
	BH
	SPB
	BPB
	SIB
	DIB
	R8B
	R9B
	R10B
	R11B
	R12B
	R13B
	R14B
	R15B

	// 16-bit

// The _offset and _postindex suffixes force the given addressing mode.
// The rest should be somewhat self-explanatory, at least given
// the decodeArg function.
type instArg uint8

const (
	_ instArg = iota
	arg_APSR
	arg_FPSCR
	arg_Dn_half
	arg_R1_0
	arg_R1_12
	arg_R2_0
	arg_R2_12
	arg_R_0
	arg_R_12
	arg_R_12_nzcv
	arg_R_16
	arg_R_16_WB
	arg_R_8
	arg_R_rotate
	arg_R_shift_R

				// init expression/func declaration which contains
				// them: use existing package-level declaration info.
				decl := check.decl // capture for use in closure below
				iota := check.iota // capture for use in closure below (go.dev/issue/22345)
				// Don't type-check right away because the function may
				// be part of a type definition to which the function

//
// Note that traceBlockReasons should not be compared, since reasons that are
// distinct by name may *not* be distinct by value.
type traceBlockReason uint8

const (
	traceBlockGeneric traceBlockReason = iota
	traceBlockForever
	traceBlockNet
	traceBlockSelect
	traceBlockCondWait
	traceBlockSync
	traceBlockChanSend
	traceBlockChanRecv
	traceBlockGCMarkAssist
	traceBlockGCSweep
	traceBlockSystemGoroutine

	fin     [(_FinBlockSize - 2*goarch.PtrSize - 2*4) / unsafe.Sizeof(finalizer{})]finalizer
}

var fingStatus atomic.Uint32

// finalizer goroutine status.
const (
	fingUninitialized uint32 = iota
	fingCreated       uint32 = 1 << (iota - 1)
	fingRunningFinalizer
	fingWait
	fingWake
)

var finlock mutex  // protects the following variables
var fing *g        // goroutine that runs finalizers