// Copyright 2021 The CC Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package cc // import "modernc.org/cc/v5"

import (
	"bytes"
	"fmt"
	"strings"
)

var defaultKeywords = map[string]rune{
	// C99
	"_Bool":      rune(BOOL),
	"_Complex":   rune(COMPLEX),
	"_Imaginary": rune(IMAGINARY),
	"auto":       rune(AUTO),
	"break":      rune(BREAK),
	"case":       rune(CASE),
	"char":       rune(CHAR),
	"const":      rune(CONST),
	"continue":   rune(CONTINUE),
	"default":    rune(DEFAULT),
	"do":         rune(DO),
	"double":     rune(DOUBLE),
	"else":       rune(ELSE),
	"enum":       rune(ENUM),
	"extern":     rune(EXTERN),
	"float":      rune(FLOAT),
	"for":        rune(FOR),
	"goto":       rune(GOTO),
	"if":         rune(IF),
	"inline":     rune(INLINE),
	"int":        rune(INT),
	"long":       rune(LONG),
	"register":   rune(REGISTER),
	"restrict":   rune(RESTRICT),
	"return":     rune(RETURN),
	"short":      rune(SHORT),
	"signed":     rune(SIGNED),
	"sizeof":     rune(SIZEOF),
	"static":     rune(STATIC),
	"struct":     rune(STRUCT),
	"switch":     rune(SWITCH),
	"typedef":    rune(TYPEDEF),
	"union":      rune(UNION),
	"unsigned":   rune(UNSIGNED),
	"void":       rune(VOID),
	"volatile":   rune(VOLATILE),
	"while":      rune(WHILE),

	// C11
	"_Alignas":       rune(ALIGNAS),
	"_Alignof":       rune(ALIGNOF),
	"_Atomic":        rune(ATOMIC),
	"_Generic":       rune(GENERIC),
	"_Noreturn":      rune(NORETURN),
	"_Static_assert": rune(STATICASSERT),
	"_Thread_local":  rune(THREADLOCAL),

	// GCC/clang/other extensions.
	"_Decimal128":   rune(DECIMAL128),
	"_Decimal32":    rune(DECIMAL32),
	"_Decimal64":    rune(DECIMAL64),
	"_Float128":     rune(FLOAT128),
	"_Float128x":    rune(FLOAT128X),
	"_Float16":      rune(FLOAT16),
	"_Float32":      rune(FLOAT32),
	"_Float32x":     rune(FLOAT32X),
	"_Float64":      rune(FLOAT64),
	"_Float64x":     rune(FLOAT64X),
	"_Nonnull":      rune(NONNULL),
	"__alignof":     rune(ALIGNOF),
	"__alignof__":   rune(ALIGNOF),
	"__asm":         rune(ASM),
	"__asm__":       rune(ASM),
	"__attribute":   rune(ATTRIBUTE),
	"__attribute__": rune(ATTRIBUTE),
	"__auto_type":   rune(AUTOTYPE),
	"__complex":     rune(COMPLEX),
	"__complex__":   rune(COMPLEX),
	"__const":       rune(CONST),
	"__declspec":    rune(DECLSPEC),
	"__float128":    rune(FLOAT128),
	"__imag":        rune(IMAG),
	"__imag__":      rune(IMAG),
	"__inline":      rune(INLINE),
	"__inline__":    rune(INLINE),
	"__int128":      rune(INT128),
	"__label__":     rune(LABEL),
	"__real":        rune(REAL),
	"__real__":      rune(REAL),
	"__restrict":    rune(RESTRICT),
	"__restrict__":  rune(RESTRICT),
	"__signed":      rune(SIGNED),
	"__signed__":    rune(SIGNED),
	"__thread":      rune(THREADLOCAL),
	"__typeof":      rune(TYPEOF),
	"__typeof__":    rune(TYPEOF),
	"__uint128_t":   rune(UINT128),
	"__volatile":    rune(VOLATILE),
	"__volatile__":  rune(VOLATILE),
	"asm":           rune(ASM),
	"typeof":        rune(TYPEOF),
}

type parser struct {
	cpp        *cpp
	fnScope    *Scope
	funcTokens []Token
	keywords   map[string]rune
	prevNL     Token
	scope      *Scope
	toks       []Token

	seq int32
}

func newParser(cfg *Config, fset *fset, sources []Source) (*parser, error) {
	cpp, err := newCPP(cfg, fset, sources, nil)
	if err != nil {
		return nil, err
	}

	funcTokens := []Token{
		{Ch: rune(STATIC)},
		{Ch: rune(CONST)},
		{Ch: rune(CHAR)},
		{Ch: rune(IDENTIFIER)},
		{Ch: '['},
		{Ch: ']'},
		{Ch: '='},
		{Ch: rune(STRINGLITERAL)},
		{Ch: ';'},
	}
	if cfg.keywords == nil {
		cfg.keywords = defaultKeywords
	}
	funcTokens = funcTokens[:len(funcTokens):len(funcTokens)]
	cpp.rune()
	return &parser{
		cpp:        cpp,
		funcTokens: funcTokens,
		scope:      &Scope{},
		keywords:   cfg.keywords,
	}, nil
}

func (p *parser) newScope() { p.scope = newScope(p.scope) }

func (p *parser) closeScope() {
	if parent := p.scope.Parent; parent != nil {
		p.scope = parent
		return
	}

	p.rune(false)
	p.cpp.eh("%v: internal error (%v:)", p.toks[0].Position(), origin(1))
	if isTesting {
		trc("%v: internal error (%v:)", p.toks[0].Position(), origin(1))
	}
}

func (p *parser) isKeyword(s []byte) (r rune, ok bool) {
	r, ok = p.keywords[string(s)]
	return r, ok
}

func (p *parser) next() {
	var b []byte
	set := false
	if p.prevNL.Ch != 0 {
		b = p.prevNL.Sep()
		set = true
	}
	for {
		p.cpp.rune()
		t := p.cpp.shift()
		switch t.Ch {
		case ' ':
			// nop
		case '\n':
			if p.prevNL.Ch != 0 {
				b = append(b, p.prevNL.Src()...)
				set = true
			}
			p.prevNL = t
			b = append(b, t.Sep()...)
		default:
			if set && !bytes.Equal(b, p.prevNL.Sep()) {
				p.prevNL.Set(b, p.prevNL.Src())
			}
			p.seq++
			t.seq = p.seq
			p.toks = append(p.toks, p.tok(t))
			return
		}
	}
}

func (p *parser) rune(checkTypeName bool) (r rune) {
	if len(p.toks) == 0 {
		p.next()
	}
	switch {
	case checkTypeName:
		t := p.toks[0]
		p.checkTypeName(&t)
		return t.Ch
	default:
		return p.toks[0].Ch
	}
}

func (p *parser) checkTypeName(t *Token) (r bool) {
	if t.Ch != rune(IDENTIFIER) {
		return false
	}

	if x, ok := p.scope.ident(*t).(*Declarator); ok {
		if x.isTypename {
			t.Ch = rune(TYPENAME)
			return true
		}
	}

	return false
}

func (p *parser) tok(t Token) (r Token) {
	r = t
	switch t.Ch {
	case rune(IDENTIFIER):
		if c, ok := p.isKeyword(r.Src()); ok {
			r.Ch = c
			break
		}
	case rune(PPNUMBER):
		switch s := r.SrcStr(); {
		case strings.ContainsAny(s, ".+-ijpIJP"):
			r.Ch = rune(FLOATCONST)
		case strings.HasPrefix(s, "0x") || strings.HasPrefix(s, "0X"):
			r.Ch = rune(INTCONST)
		case strings.ContainsAny(s, "Ee"):
			r.Ch = rune(FLOATCONST)
		default:
			r.Ch = rune(INTCONST)
		}
	}
	return r
}

func (p *parser) shift0() (r Token) {
	r = p.toks[0]
	if r.Ch != '\n' && p.prevNL.Ch != 0 {
		sep := append(p.prevNL.Sep(), p.prevNL.Src()...)
		sep = append(sep, r.Sep()...)
		r.Set(sep, r.Src())
	}
	if r.Ch != eof {
		switch {
		case len(p.toks) == 1:
			p.toks = p.toks[:0]
		default:
			p.toks = p.toks[1:]
		}
		p.prevNL.Ch = 0
		p.rune(false)
	}
	return r
}

func (p *parser) shift(checkTypeName bool) (r Token) {
	r = p.shift0()
	// if r.Ch != ' ' && r.Ch != '\n' {
	// 	trc("%v: %v", pos(r), r)
	// }
	switch {
	case r.Ch == rune(STRINGLITERAL) && p.rune(false) == rune(STRINGLITERAL):
		sep := r.Sep()
		src := r.Src()
		for p.rune(false) == rune(STRINGLITERAL) {
			t := p.shift0()
			sep = append(sep, t.Sep()...)
			src = append(src[:len(src)-1], t.Src()[1:]...)
		}
		r.Set(sep, src)
	case r.Ch == rune(LONGSTRINGLITERAL) && (p.rune(false) == rune(LONGSTRINGLITERAL) || p.rune(false) == rune(STRINGLITERAL)):
		sep := r.Sep()
		src := r.Src()
	out:
		for {
			switch p.rune(false) {
			case rune(LONGSTRINGLITERAL):
				t := p.shift0()
				sep = append(sep, t.Sep()...)
				src = append(src[:len(src)-1], t.Src()[2:]...)
			case rune(STRINGLITERAL):
				t := p.shift0()
				sep = append(sep, t.Sep()...)
				src = append(src[:len(src)-1], t.Src()[1:]...)
			default:
				break out
			}
		}
		r.Set(sep, src)
	}
	if checkTypeName {
		p.checkTypeName(&r)
	}
	return r
}

func (p *parser) peek(i int, checkTypeName bool) (r Token) {
	for len(p.toks) <= i {
		p.next()
	}
	switch {
	case checkTypeName:
		r = p.toks[i]
		p.checkTypeName(&r)
		return r
	default:
		return p.toks[i]
	}
}

func (p *parser) must(r rune) Token {
	c := p.rune(false)
	t := p.shift(false)
	if c != r {
		p.cpp.eh("%v: unexpected %v, expected %v", t.Position(), runeName(c), runeName(r))
	}
	return t
}

func (p *parser) parse() (ast *AST, err error) {
	var errors errors
	p.cpp.eh = func(msg string, args ...interface{}) {
		s := fmt.Sprintf(msg, args...)
		if isTesting {
			s += fmt.Sprintf(" (%v: %v)", origin(2), origin(3))
			if traceFails {
				trc("%s FAIL (%v)", s, origin(1))
				// trc("\n%s", debug.Stack())
			}
		}
		errors = append(errors, s)
	}
	tu := p.translationUnit()
	p.cpp.mmap = nil
	switch p.rune(false) {
	case eof:
		var pd *Declarator
		if a := p.scope.Nodes["__predefined_declarator"]; len(a) != 0 {
			pd, _ = a[0].(*Declarator)
		}
		if pd == nil && !p.cpp.cfg.noPredefinedDeclarator {
			errors.add(errorf("<bultin>: missing definition of '__predefined_declarator'"))
		}
		t := p.shift(false)
		t.Set(append(p.prevNL.Sep(), p.prevNL.Src()...), nil)
		return &AST{
			ABI:                   p.cpp.cfg.ABI,
			EOF:                   t,
			Macros:                p.cpp.macros,
			Scope:                 p.scope,
			Declarations:          tu,
			predefinedDeclarator0: pd,
		}, errors.err()
	default:
		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected EOF", t.Position(), runeName(t.Ch))
		return nil, errors.err()
	}
}

// [0], 6.9 External definitions
//
//  translation-unit:
// 	external-declaration
// 	translation-unit external-declaration
func (p *parser) translationUnit() (r []ExternalDeclaration) {
	for p.rune(false) != eof {
		tu := p.externalDeclaration()
		if tu == nil {
			return r
		}
		r = append(r, tu)
	}
	return r
}

//  external-declaration:
// 	function-definition
// 	declaration
// 	asm-function-definition
//	asm-statement
// 	;
func (p *parser) externalDeclaration() ExternalDeclaration {
again:
	switch p.rune(false) {
	case eof:
		return nil
	case rune(ASM):
		return p.asmStatement()
	case rune(STATICASSERT), rune(AUTOTYPE):
		return p.declaration(nil, nil, false)
	}

	ds, ok := p.declarationSpecifiers()
	if !ok {
		goto again
	}

	var d *Declarator
	if p.rune(false) != ';' {
		d = p.declarator(nil, ds, true)
	}
	switch p.rune(false) {
	case
		',',
		';',
		'=',
		rune(ASM),
		rune(ATTRIBUTE):

		//TODO wrong parse of pr37573.c
		return p.declaration(ds, d, true)
	case '{':
		return p.functionDefinition(ds, d)
	default:
		if d.isFn() {
			return p.functionDefinition(ds, d)
		}

		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected external declaration", t.Position(), runeName(t.Ch))
		return nil
	}
}

// [0], 6.9.1 Function definitions
//
//  function-definition:
// 	declaration-specifiers declarator declaration-list_opt compound-statement
func (p *parser) functionDefinition(ds DeclarationSpecifiers, d *Declarator) (r *FunctionDefinition) {
	defer func() {
		r.scope = p.fnScope
		p.fnScope = nil
	}()
	d.isFuncDef = true
	return &FunctionDefinition{Specifiers: ds, Declarator: d, Declarations: p.declarationListOpt(), Body: p.compoundStatement(true, d)}
}

//  declaration-list:
// 	declaration
// 	declaration-list declaration
func (p *parser) declarationListOpt() (r []Declaration) {
	for {
		switch p.rune(false) {
		case '{', eof:
			return r
		}
		r = append(r, p.declaration(nil, nil, false))
	}
}

// [0], 6.8.2 Compound statement
//
//  compound-statement:
// 	{ label-declaration_opt block-item-list_opt }
func (p *parser) compoundStatement(isFnScope bool, d *Declarator) (r *CompoundStatement) {
	p.newScope()

	defer p.closeScope()

	if isFnScope {
		p.fnScope = p.scope
		if d != nil {
			for dd := d.DirectDeclarator; dd != nil; {
				if s := dd.params; s != nil {
					for nm, nodes := range s.Nodes {
						for _, node := range nodes {
							p.scope.declare(p.cpp.eh, nm, node)
						}
					}
				}
				switch dd.Case {
				case DirectDeclaratorIdent:
					dd = nil
				case DirectDeclaratorDecl:
					dd = dd.Declarator.DirectDeclarator
				default:
					dd = dd.DirectDeclarator
				}
			}
		}
	}
	lbrace := p.must('{')
	if isFnScope && d != nil && !p.cpp.cfg.doNotInjectFunc {
		p.injectFuncTokens(lbrace, d.Name())
	}
	return &CompoundStatement{Lbrace: lbrace, List: p.blockItemListOpt(), Rbrace: p.must('}'), lexicalScope: (*lexicalScope)(p.scope)}
}

var funcTokensText = [][]byte{
	[]byte("static"),        // 0
	[]byte("const"),         // 1
	[]byte("char"),          // 2
	[]byte("__func__"),      // 3
	[]byte("["),             // 4
	[]byte("]"),             // 5
	[]byte("="),             // 6
	[]byte("function-name"), // 7
	[]byte(";"),             // 8
}

func (p *parser) injectFuncTokens(lbrace Token, nm string) {
	seq := lbrace.seq
	for i := range p.funcTokens {
		pt := &p.funcTokens[i]
		pt.s = lbrace.s
		pt.off = lbrace.off
		seq++
		pt.seq = seq
		if i != 7 {
			pt.Set(sp, funcTokensText[i])
		}
	}
	p.funcTokens[7].Set(sp, []byte(`"`+nm+`"`))
	p.rune(false)
	for i := range p.toks {
		seq++
		p.toks[i].seq = seq
	}
	p.seq = seq + 1
	p.toks = append(p.funcTokens, p.toks...)
}

//  block-item-list:
// 	block-item
// 	block-item-list block-item
func (p *parser) blockItemListOpt() (r []BlockItem) {
	for {
		switch p.rune(false) {
		case '}', eof:
			return r
		default:
			r = append(r, p.blockItem())
		}
	}
}

//  block-item:
// 	declaration
// 	statement
// 	label-declaration
// 	declaration-specifiers declarator compound-statement
func (p *parser) blockItem() BlockItem {
again:
	switch ch := p.rune(true); {
	case p.isStatement(ch) || p.isExpression(ch) || ch == rune(TYPENAME) && p.peek(1, false).Ch == ':':
		return p.statement(false)
	case p.isDeclarationSpecifier(ch, true):
		r0 := p.rune(false)
		ds, ok := p.declarationSpecifiers()
		if !ok {
			goto again
		}

		if r0 == rune(ATTRIBUTE) && p.rune(false) == ';' {
			return &ExpressionStatement{declarationSpecifiers: ds, AttributeSpecifiers: p.attributeSpecifierListOpt(), Token: p.shift(false)}
		}

		var d *Declarator
		if p.rune(false) != ';' {
			d = p.declarator(nil, ds, true)
		}
		switch p.rune(false) {
		case '{':
			fd := &FunctionDefinition{Specifiers: ds, Declarator: d, Body: p.compoundStatement(true, d)}
			fd.scope = fd.Body.LexicalScope()
			return fd
		default:
			return p.declaration(ds, d, true)
		}
	case ch == rune(LABEL):
		return p.labelDeclaration()
	case ch == rune(STATICASSERT), ch == rune(AUTOTYPE):
		return p.declaration(nil, nil, false)
	default:
		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected block item", t.Position(), runeName(t.Ch))
		return nil
	}
}

//  label-declaration
// 	__label__ identifier-list ;
func (p *parser) labelDeclaration() (r *LabelDeclaration) {
	r = &LabelDeclaration{Token: p.shift(false), IdentifierList: p.identifierList(false), Token2: p.must(';')}
	for l := r.IdentifierList; l != nil; l = l.IdentifierList {
		p.scope.declare(p.cpp.eh, l.Token2.SrcStr(), r)
	}
	return r
}

// [0], 6.8 Statements and blocks
//
//  statement:
// 	labeled-statement
// 	compound-statement
// 	expression-statement
// 	selection-statement
// 	iteration-statement
// 	jump-statement
//	asm-statement
func (p *parser) statement(newBlock bool) Statement {
	if newBlock {
		p.newScope()

		defer p.closeScope()
	}
	switch ch := p.rune(false); {
	case ch == rune(IDENTIFIER):
		switch p.peek(1, false).Ch {
		case ':':
			return p.labeledStatement()
		default:
			return p.expressionStatement()
		}
	case p.isExpression(ch) || ch == ';' || ch == rune(ATTRIBUTE):
		return p.expressionStatement()
	}

	switch p.rune(true) {
	case eof:
		p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
		return nil
	case '{':
		return p.compoundStatement(false, nil)
	case rune(ASM):
		return p.asmStatement()
	case
		rune(DO),
		rune(FOR),
		rune(WHILE):

		return p.iterationStatement()
	case
		rune(BREAK),
		rune(CONTINUE),
		rune(GOTO),
		rune(RETURN):

		return p.jumpStatement()
	case
		rune(IF),
		rune(SWITCH):

		return p.selectionStatement()
	case
		rune(CASE),
		rune(DEFAULT):

		return p.labeledStatement()
	default:
		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected statement", t.Position(), runeName(t.Ch))
		return nil
	}
}

func (p *parser) isStatement(ch rune) bool {
	switch ch {
	case
		'(',
		'*',
		';',
		'{',
		rune(ASM),
		rune(BREAK),
		rune(CASE),
		rune(CONTINUE),
		rune(DEC),
		rune(DEFAULT),
		rune(DO),
		rune(FOR),
		rune(GOTO),
		rune(IDENTIFIER),
		rune(IF),
		rune(INC),
		rune(LONGSTRINGLITERAL),
		rune(RETURN),
		rune(STRINGLITERAL),
		rune(SWITCH),
		rune(WHILE):

		return true
	}
	return false
}

// [0], 6.8.4 Selection statements
//
//  selection-statement:
//  	if ( expression ) statement
//  	if ( expression ) statement else statement
//  	switch ( expression ) statement
func (p *parser) selectionStatement() (r *SelectionStatement) {
	p.newScope()

	defer p.closeScope()

	switch p.rune(false) {
	case eof:
		p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
		return nil
	case rune(IF):
		r = &SelectionStatement{Case: SelectionStatementIf, Token: p.shift(false), Token2: p.must('('), ExpressionList: p.expression(false), Token3: p.must(')'), Statement: p.statement(true)}
		switch p.rune(false) {
		case rune(ELSE):
			r.Case = SelectionStatementIfElse
			r.Token4 = p.shift(false)
			r.Statement2 = p.statement(true)
			return r
		default:
			return r
		}
	case rune(SWITCH):
		return &SelectionStatement{Case: SelectionStatementSwitch, Token: p.shift(false), Token2: p.must('('), ExpressionList: p.expression(false), Token3: p.must(')'), Statement: p.statement(true)}
	default:
		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected selection statement", t.Position(), runeName(t.Ch))
		return nil
	}
}

// [0], 6.8.6 Jump statements
//
//  jump-statement:
// 	goto identifier ;
// 	goto * expression ;
// 	continue ;
// 	break ;
// 	return expression_opt ;
func (p *parser) jumpStatement() *JumpStatement {
	switch p.rune(false) {
	case eof:
		p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
		return nil
	case rune(BREAK):
		return &JumpStatement{Case: JumpStatementBreak, Token: p.shift(false), Token2: p.must(';')}
	case rune(CONTINUE):
		return &JumpStatement{Case: JumpStatementContinue, Token: p.shift(false), Token2: p.must(';')}
	case rune(GOTO):
		switch p.peek(1, false).Ch {
		case '*':
			return &JumpStatement{Case: JumpStatementGotoExpr, Token: p.shift(false), Token2: p.shift(false), ExpressionList: p.expression(false), Token3: p.must(';')}
		default:
			return &JumpStatement{Case: JumpStatementGoto, Token: p.shift(false), Token2: p.must(rune(IDENTIFIER)), Token3: p.must(';')}
		}
	case rune(RETURN):
		return &JumpStatement{Case: JumpStatementReturn, Token: p.shift(false), ExpressionList: p.expression(true), Token2: p.must(';')}
	default:
		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected jump statement", t.Position(), runeName(t.Ch))
		return nil
	}
}

// [0], 6.8.1 Labeled statements
//
//  labeled-statement:
// 	identifier : statement
// 	case constant-expression : statement
// 	case constant-expression ... constant-expression : statement
// 	default : statement
func (p *parser) labeledStatement() (r *LabeledStatement) {
	switch p.rune(false) {
	case eof:
		p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
		return nil
	case rune(CASE):
		r = &LabeledStatement{Token: p.shift(false), Expression: p.constantExpression()}
		switch p.rune(false) {
		case rune(DDD):
			r.Case = LabeledStatementRange
			r.Token2 = p.shift(false)
			r.Expression2 = p.constantExpression()
			r.Token3 = p.must(':')
			r.Statement = p.statement(false)
			return r
		default:
			r.Case = LabeledStatementCaseLabel
			r.Token2 = p.must(':')
			r.Statement = p.statement(false)
			return r
		}
	case rune(DEFAULT):
		return &LabeledStatement{Case: LabeledStatementDefault, Token: p.shift(false), Token2: p.must(':'), Statement: p.statement(false)}
	case rune(IDENTIFIER):
		r = &LabeledStatement{Case: LabeledStatementLabel, Token: p.shift(false), Token2: p.must(':'), Statement: p.statement(false)}
		switch {
		case p.fnScope == nil:
			t := p.shift(false)
			p.cpp.eh("%v: unexpected label", t.Position())
		default:
			p.fnScope.declare(p.cpp.eh, r.Token.SrcStr(), r)
		}
		return r
	default:
		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected labeled statement", t.Position(), runeName(t.Ch))
		return nil
	}
}

// [0], 6.8.5 Iteration statements
//
//  iteration-statement:
// 	while ( expression ) statement
// 	do statement while ( expression ) ;
// 	for ( expression_opt ; expression_opt ; expression_opt ) statement
// 	for ( declaration expression_opt ; expression_opt ) statement
func (p *parser) iterationStatement() (r *IterationStatement) {
	p.newScope()

	defer p.closeScope()

	switch p.rune(false) {
	case rune(WHILE):
		return &IterationStatement{Case: IterationStatementWhile, Token: p.shift(false), Token2: p.must('('), ExpressionList: p.expression(false), Token3: p.must(')'), Statement: p.statement(true)}
	case rune(DO):
		return &IterationStatement{Case: IterationStatementDo, Token: p.shift(false), Statement: p.statement(true), Token2: p.must(rune(WHILE)), Token3: p.must('('), ExpressionList: p.expression(false), Token4: p.must(')'), Token5: p.must(';')}
	case rune(FOR):
		switch ch := p.peek(2, true).Ch; {
		case p.isDeclarationSpecifier(ch, true):
			return &IterationStatement{Case: IterationStatementForDecl, Token: p.shift(false), Token2: p.must('('), Declaration: p.declaration(nil, nil, true), ExpressionList: p.expression(true), Token3: p.must(';'), ExpressionList2: p.expression(true), Token4: p.must(')'), Statement: p.statement(true)}
		}

		return &IterationStatement{Case: IterationStatementFor, Token: p.shift(false), Token2: p.must('('), ExpressionList: p.expression(true), Token3: p.must(';'), ExpressionList2: p.expression(true), Token4: p.must(';'), ExpressionList3: p.expression(true), Token5: p.must(')'), Statement: p.statement(true)}
	default:
		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected iteration statement", t.Position(), runeName(t.Ch))
		return nil
	}
}

// [0], 6.8.3 Expression and null statements
//
//  expression-statement:
// 	expression_opt;
func (p *parser) expressionStatement() *ExpressionStatement {
	switch p.rune(false) {
	case rune(ATTRIBUTE):
		t := p.shift(false)
		p.cpp.eh("%v: internal error: TODO", t.Position(), runeName(t.Ch))
		return nil
	default:
		return &ExpressionStatement{ExpressionList: p.expression(true), Token: p.must(';')}
	}
}

//  asm-statement:
//  	asm ;
func (p *parser) asmStatement() *AsmStatement {
	return &AsmStatement{Asm: p.asm(), Token: p.must(';')}
}

//  asm:
// 	asm asm-qualifier-list_opt ( string-literal asm-arg-list_opt )
func (p *parser) asm() *Asm {
	return &Asm{Token: p.must(rune(ASM)), AsmQualifierList: p.asmQualifierListOpt(), Token2: p.must('('), Token3: p.must(rune(STRINGLITERAL)), AsmArgList: p.asmArgListOpt(), Token4: p.must(')')}
}

//  asm-qualifier-list:
// 	asm-qualifier
// 	asm-qualifier-list asm-qualifier
func (p *parser) asmQualifierListOpt() (r *AsmQualifierList) {
	var prev *AsmQualifierList
	for {
		switch p.rune(false) {
		case eof:
			p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
			return r
		case rune(GOTO), rune(INLINE), rune(VOLATILE):
			aql := &AsmQualifierList{AsmQualifier: p.asmQualifier()}
			switch {
			case r == nil:
				r = aql
			default:
				prev.AsmQualifierList = aql
			}
			prev = aql
		default:
			return r
		}
	}
}

//  asm-qualifier:
// 	volatile
//  	inline
// 	goto"
func (p *parser) asmQualifier() *AsmQualifier {
	switch p.rune(false) {
	case eof:
		p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
		return nil
	case rune(VOLATILE):
		return &AsmQualifier{Case: AsmQualifierVolatile, Token: p.shift(false)}
	case rune(INLINE):
		return &AsmQualifier{Case: AsmQualifierInline, Token: p.shift(false)}
	case rune(GOTO):
		return &AsmQualifier{Case: AsmQualifierGoto, Token: p.shift(false)}
	default:
		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected asm qualifier", t.Position(), runeName(t.Ch))
		return nil
	}
}

//  asm-arg-list:
// 	: asm-expression-list
// 	asm-arg-list : asm-expression-list
func (p *parser) asmArgListOpt() (r *AsmArgList) {
	var prev *AsmArgList
	for p.rune(false) == ':' {
		var aal *AsmArgList
		switch p.peek(1, false).Ch {
		case
			')',
			':':

			aal = &AsmArgList{Token: p.shift(false)}
		default:
			aal = &AsmArgList{Token: p.shift(false), AsmExpressionList: p.asmExpressionList()}
		}
		switch {
		case r == nil:
			r = aal
		default:
			prev.AsmArgList = aal
		}
		prev = aal
	}
	return r
}

//  asm-expression-list:
// 	asm-index_opt assignment-expression
// 	asm-expression-list , asm-index_opt assignment-expression
func (p *parser) asmExpressionList() (r *AsmExpressionList) {
	r = &AsmExpressionList{AsmIndex: p.asmIndexOpt(), Expression: p.assignmentExpression(true)}
	prev := r
	for p.rune(false) == ',' {
		ael := &AsmExpressionList{Token: p.shift(false), AsmIndex: p.asmIndexOpt(), Expression: p.assignmentExpression(true)}
		prev.AsmExpressionList = ael
		prev = ael
	}
	return r
}

//  asm-index:
// 	[ expression ]
func (p *parser) asmIndexOpt() *AsmIndex {
	if p.rune(false) != '[' {
		return nil
	}

	return &AsmIndex{Token: p.shift(false), ExpressionList: p.expression(false), Token2: p.must(']')}
}

// [0], 6.5.17 Comma operator
//
//  expression:
// 	assignment-expression
// 	expression , assignment-expression
func (p *parser) expression(opt bool) Expression {
	var r *ExpressionList
	if p.isExpression(p.rune(false)) {
		ae := p.assignmentExpression(true)
		if p.rune(false) != ',' {
			return ae
		}

		r = &ExpressionList{List: []Expression{ae}}
		for p.rune(false) == ',' {
			r.Tokens = append(r.Tokens, p.shift(false))
			r.List = append(r.List, p.assignmentExpression(true))
		}
		return r
	}

	if opt {
		return nil
	}

	t := p.shift(false)
	p.cpp.eh("%v: unexpected %v, expected asm expression", t.Position(), runeName(t.Ch))
	return nil
}

func (p *parser) isExpression(ch rune) bool {
	switch ch {
	case
		'!',
		'&',
		'(',
		'*',
		'+',
		'-',
		'~',
		rune(ALIGNOF),
		rune(ANDAND),
		rune(CHARCONST),
		rune(DEC),
		rune(FLOATCONST),
		rune(GENERIC),
		rune(IDENTIFIER),
		rune(IMAG),
		rune(INC),
		rune(INTCONST),
		rune(LONGCHARCONST),
		rune(LONGSTRINGLITERAL),
		rune(REAL),
		rune(SIZEOF),
		rune(STRINGLITERAL):

		return true
	}
	return false
}

// [0], 6.7 Declarations
//
//  declaration:
// 	declaration-specifiers init-declarator-list_opt attribute-specifier-list_opt;
//	static-assert-declaration
//	__auto_type ident = initializer ;
func (p *parser) declaration(ds DeclarationSpecifiers, d *Declarator, declare bool) (r Declaration) {
	switch p.rune(false) {
	case rune(STATICASSERT):
		return p.staticAssertDeclaration()
	case rune(AUTOTYPE):
		nm := p.peek(1, true)
		if nm.Ch != rune(IDENTIFIER) {
			p.cpp.eh("%v: unexpected %v, expected identifier", nm.Position(), runeName(nm.Ch))
			p.shift(false)
			p.shift(false)
			return nil
		}

		a := &AutoDeclaration{Token: p.shift(false), Declarator: p.declarator(nil, nil, false)}
		r = a
		a.Token2 = p.must('=')
		a.Initializer = p.initializer(nil)
		a.Token3 = p.must(';')
		a.Declarator.visible = visible(a.Token3.seq)
		p.scope.declare(p.cpp.eh, nm.SrcStr(), a.Declarator)
		return r
	}

	if len(ds) == 0 {
		var ok bool
		if ds, ok = p.declarationSpecifiers(); !ok {
			return nil
		}
	}

	return &CommonDeclaration{DeclarationSpecifiers: ds, InitDeclarators: p.initDeclaratorListOpt(ds, d, declare), AttributeSpecifiers: p.attributeSpecifierListOpt(), Token: p.must(';')}
}

//  static-assert-declaration
//	_Static_assert ( constant-expression , string-literal )
func (p *parser) staticAssertDeclaration() *StaticAssertDeclaration {
	return &StaticAssertDeclaration{Token: p.must(rune(STATICASSERT)), Token2: p.must('('), Expression: p.constantExpression(), Token3: p.must(','), Token4: p.must(rune(STRINGLITERAL)), Token5: p.must(')')}
}

//  attribute-specifier-list:
// 	attribute-specifier
// 	attribute-specifier-list attribute-specifier
func (p *parser) attributeSpecifierListOpt() (r []*AttributeSpecifier) {
	for p.rune(false) == rune(ATTRIBUTE) {
		r = append(r, p.attributeSpecifier())
	}
	return r
}

//  attribute-specifier:
// 	__attribute__ (( attribute-value-list_opt ))
func (p *parser) attributeSpecifier() (r *AttributeSpecifier) {
	return &AttributeSpecifier{Token: p.must(rune(ATTRIBUTE)), Token2: p.must('('), Token3: p.must('('), AttributeValueList: p.attributeValueListOpt(), Token4: p.must(')'), Token5: p.must(')')}
}

//  attribute-value-list:
// 	attribute-value
// 	attribute-value-list , attribute-value
func (p *parser) attributeValueListOpt() (r *AttributeValueList) {
	switch p.rune(false) {
	case eof:
		return r
	case rune(IDENTIFIER):
		r = &AttributeValueList{AttributeValue: p.attributeValue()}
	case ')':
		return nil
	default:
		if _, ok := p.isKeyword(p.toks[0].Src()); ok {
			r = &AttributeValueList{AttributeValue: p.attributeValue()}
			break
		}

		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected attribute value", t.Position(), runeName(t.Ch))
	}
	prev := r
	for p.rune(false) == ',' {
		avl := &AttributeValueList{Token: p.shift(false), AttributeValue: p.attributeValue()}
		prev.AttributeValueList = avl
	}
	return r
}

//  attribute-value:
// 	identifier
// 	identifier ( expression-list_opt )
func (p *parser) attributeValue() (r *AttributeValue) {
	switch p.rune(false) {
	case eof:
		p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
		return nil
	case rune(IDENTIFIER):
		switch p.peek(1, false).Ch {
		case '(':
			return &AttributeValue{Case: AttributeValueExpr, Token: p.shift(false), Token2: p.shift(false), ArgumentExpressionList: p.argumentExpressionListOpt(false), Token3: p.must(')')}
		default:
			return &AttributeValue{Case: AttributeValueIdent, Token: p.shift(false)}
		}
	default:
		if _, ok := p.isKeyword(p.toks[0].Src()); ok {
			r = &AttributeValue{Case: AttributeValueIdent, Token: p.shift(false)}
			r.Token.Ch = rune(IDENTIFIER)
			return r
		}

		p.cpp.eh("%v: unexpected %v, expected identifier", p.toks[0].Position(), runeName(p.rune(false)))
		p.shift(false)
		return nil
	}
}

//  init-declarator-list:
// 	init-declarator
// 	init-declarator-list , init-declarator
func (p *parser) initDeclaratorListOpt(ds DeclarationSpecifiers, d *Declarator, declare bool) (r []*InitDeclarator) {
	switch {
	case d == nil:
		switch p.rune(false) {
		case eof:
			p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
			return nil
		case ';':
			return nil
		case
			'(',
			'*',
			rune(IDENTIFIER):

			d = p.declarator(nil, ds, declare)
		default:
			p.cpp.eh("%v: unexpected %v, expected direct-declarator", p.toks[0].Position(), runeName(p.rune(false)))
			p.shift(false)
			return nil
		}
	}
	var list []*InitDeclarator
	prev := p.initDeclarator(ds, d, declare)
	list = append(list, prev)
	for p.rune(false) == ',' {
		prev.Token2 = p.shift(false)
		attrs := p.attributeSpecifierListOpt()
		prev = p.initDeclarator(ds, nil, declare)
		prev.AttributeSpecifiers = attrs
		list = append(list, prev)
	}
	return list
}

//  init-declarator:
// 	declarator asm-register-var_opt
// 	declarator asm-register-var_opt = initializer
func (p *parser) initDeclarator(ds DeclarationSpecifiers, d *Declarator, declare bool) (r *InitDeclarator) {
	if d == nil {
		d = p.declarator(nil, ds, declare)
	}

	r = &InitDeclarator{Declarator: d}
	if p.rune(false) == rune(ASM) {
		r.Asm = p.asm()
	}
	if p.rune(false) == rune(ATTRIBUTE) {
		r.AttributeSpecifiers = p.attributeSpecifierListOpt()
	}
	if p.rune(false) == '=' {
		if d.isTypename {
			p.cpp.eh("%v: typedef '%s' is initialized", p.toks[0].Position(), d.Name())
		}
		r.Token = p.shift(false)
		r.Initializer = p.initializer(nil)
	}
	return r
}

// [0], 6.7.8 Initialization
//
//  initializer:
// 	assignment-expression
// 	{ initializer-list }
// 	{ initializer-list , }
func (p *parser) initializer(parent *Initializer) (r *Initializer) {
	switch p.rune(false) {
	case eof:
		p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
		return nil
	case '{':
		r = &Initializer{Case: InitializerInitList, Token: p.shift(false), parent: parent}
		r.InitializerList = p.initializerList(r)
		if p.rune(false) == ',' {
			r.Token2 = p.shift(false)
		}

		r.Token3 = p.must('}')
		return r
	default:
		return &Initializer{Case: InitializerExpr, Expression: p.assignmentExpression(true), parent: parent}
	}
}

//  initializer-list:
// 	designation_opt initializer
// 	initializer-list , designation_opt initializer
func (p *parser) initializerList(parent *Initializer) (r *InitializerList) {
	switch p.rune(true) {
	case eof:
		p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
		return nil
	case '[', '.':
		r = &InitializerList{Designation: p.designation(), Initializer: p.initializer(parent)}
	case rune(IDENTIFIER):
		switch p.peek(1, false).Ch {
		case ':':
			r = &InitializerList{Designation: p.designation(), Initializer: p.initializer(parent)}
		default:
			r = &InitializerList{Initializer: p.initializer(parent)}
		}
	case '{':
		r = &InitializerList{Initializer: p.initializer(parent)}
	case '}':
		return nil
	default:
		if p.isExpression(p.rune(true)) {
			r = &InitializerList{Initializer: p.initializer(parent)}
			break
		}

		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected designation or initializer", t.Position(), runeName(t.Ch))
	}
	prev := r
	for p.rune(false) == ',' {
		var il *InitializerList
		switch p.peek(1, true).Ch {
		case
			'.',
			'[':

			il = &InitializerList{Token: p.shift(false), Designation: p.designation(), Initializer: p.initializer(parent)}
		case rune(IDENTIFIER):
			switch p.peek(2, false).Ch {
			case ':':
				il = &InitializerList{Token: p.shift(false), Designation: p.designation(), Initializer: p.initializer(parent)}
			default:
				il = &InitializerList{Token: p.shift(false), Initializer: p.initializer(parent)}
			}
		case '}':
			return r
		default:
			il = &InitializerList{Token: p.shift(false), Initializer: p.initializer(parent)}
		}
		prev.InitializerList = il
		prev = il
	}
	return r
}

//  designation:
// 	designator-list =
func (p *parser) designation() (r *Designation) {
	p.rune(false)
	dl, last := p.designatorList()
	r = &Designation{Designators: dl}
	if last != DesignatorField2 {
		r.Token = p.must('=')
	}
	return r
}

//  designator-list:
// 	designator
// 	designator-list designator
func (p *parser) designatorList() (r []*Designator, last DesignatorCase) {
	for {
		var dl *Designator
		switch p.rune(true) {
		case eof:
			p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
			return nil, 0
		case '[', '.':
			dl = p.designator()
		case rune(IDENTIFIER):
			switch p.peek(1, false).Ch {
			case ':':
				dl = p.designator()
			default:
				return r, last
			}
		default:
			return r, last
		}
		last = dl.Case
		r = append(r, dl)
	}
}

//  designator:
// 	[ constant-expression ]
// 	[ constant-expression ... constant-expression]
// 	. identifier
//	identifier :
func (p *parser) designator() (r *Designator) {
	switch p.rune(true) {
	case eof:
		p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
		return nil
	case '[':
		r = &Designator{Case: DesignatorIndex, Token: p.shift(false), ConstantExpression: p.constantExpression()}
		switch p.rune(false) {
		case rune(DDD):
			r.Case = DesignatorIndex2
			r.Token2 = p.shift(false)
			r.ConstantExpression2 = p.constantExpression()
			r.Token3 = p.must(']')
			return r
		default:
			r.Token2 = p.must(']')
			return r
		}
	case '.':
		return &Designator{Case: DesignatorField, Token: p.shift(false), Token2: p.must(rune(IDENTIFIER))}
	case rune(IDENTIFIER):
		switch p.peek(1, false).Ch {
		case ':':
			return &Designator{Case: DesignatorField2, Token: p.shift(false), Token2: p.shift(false)}
		default:
			t := p.shift(false)
			p.cpp.eh("%v: unexpected %v, expected designator", t.Position(), runeName(t.Ch))
			return nil
		}
	default:
		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected designator", t.Position(), runeName(t.Ch))
		return nil
	}
}

// [0], 6.5.16 Assignment operators
//
//  assignment-expression:
// 	conditional-expression
// 	unary-expression assignment-operator assignment-expression
//
//  assignment-operator: one of
// 	= *= /= %= += -= <<= >>= &= ^= |=
func (p *parser) assignmentExpression(checkTypeName bool) Expression {
	lhs, u := p.conditionalExpression(checkTypeName)
	var r *AssignmentExpression
	switch p.rune(false) {
	case eof:
		p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
		return nil
	case '=':
		r = &AssignmentExpression{Lhs: u, Op: AssignmentOperationAssign, Token: p.shift(false), Rhs: p.assignmentExpression(checkTypeName)}
	case rune(MULASSIGN):
		r = &AssignmentExpression{Lhs: u, Op: AssignmentOperationMul, Token: p.shift(false), Rhs: p.assignmentExpression(checkTypeName)}
	case rune(DIVASSIGN):
		r = &AssignmentExpression{Lhs: u, Op: AssignmentOperationDiv, Token: p.shift(false), Rhs: p.assignmentExpression(checkTypeName)}
	case rune(MODASSIGN):
		r = &AssignmentExpression{Lhs: u, Op: AssignmentOperationMod, Token: p.shift(false), Rhs: p.assignmentExpression(checkTypeName)}
	case rune(ADDASSIGN):
		r = &AssignmentExpression{Lhs: u, Op: AssignmentOperationAdd, Token: p.shift(false), Rhs: p.assignmentExpression(checkTypeName)}
	case rune(SUBASSIGN):
		r = &AssignmentExpression{Lhs: u, Op: AssignmentOperationSub, Token: p.shift(false), Rhs: p.assignmentExpression(checkTypeName)}
	case rune(LSHASSIGN):
		r = &AssignmentExpression{Lhs: u, Op: AssignmentOperationLsh, Token: p.shift(false), Rhs: p.assignmentExpression(checkTypeName)}
	case rune(RSHASSIGN):
		r = &AssignmentExpression{Lhs: u, Op: AssignmentOperationRsh, Token: p.shift(false), Rhs: p.assignmentExpression(checkTypeName)}
	case rune(ANDASSIGN):
		r = &AssignmentExpression{Lhs: u, Op: AssignmentOperationAnd, Token: p.shift(false), Rhs: p.assignmentExpression(checkTypeName)}
	case rune(XORASSIGN):
		r = &AssignmentExpression{Lhs: u, Op: AssignmentOperationXor, Token: p.shift(false), Rhs: p.assignmentExpression(checkTypeName)}
	case rune(ORASSIGN):
		r = &AssignmentExpression{Lhs: u, Op: AssignmentOperationOr, Token: p.shift(false), Rhs: p.assignmentExpression(checkTypeName)}
	default:
		return lhs
	}
	if u == nil {
		p.cpp.eh("%v: LHS must be unary-expression", r.Token.Position())
	}
	return r
}

// [0], 6.5.15 Conditional operator
//
//  conditional-expression:
// 	logical-OR-expression
// 	logical-OR-expression ? expression : conditional-expression
func (p *parser) conditionalExpression(checkTypeName bool) (r, u Expression) {
	lhs, u := p.logicalOrExpression(checkTypeName)
	switch p.rune(false) {
	case eof:
		p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
		return nil, nil
	case '?':
		r := &ConditionalExpression{Condition: lhs, Token: p.shift(false), Then: p.expression(true), Token2: p.must(':')}
		r.Else, _ = p.conditionalExpression(checkTypeName)
		return r, nil
	default:
		return lhs, u
	}
}

// [0], 6.5.14 Logical OR operator
//
//  logical-OR-expression:
// 	logical-AND-expression
// 	logical-OR-expression || logical-AND-expression
func (p *parser) logicalOrExpression(checkTypeName bool) (r, u Expression) {
	r, u = p.logicalAndExpression(checkTypeName)
	var s *BinaryExpression
	for {
		switch p.rune(false) {
		case eof:
			p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
			return nil, nil
		case rune(OROR):
			s = &BinaryExpression{Lhs: r, Op: BinaryOperationLOr, Token: p.shift(false)}
			s.Rhs, _ = p.logicalAndExpression(checkTypeName)
		default:
			return r, u
		}
		r = s
		u = nil
	}
}

// [0], 6.5.13 Logical AND operator
//
//  logical-AND-expression:
// 	inclusive-OR-expression
// 	logical-AND-expression && inclusive-OR-expression
func (p *parser) logicalAndExpression(checkTypeName bool) (r, u Expression) {
	r, u = p.inclusiveOrExpression(checkTypeName)
	var s *BinaryExpression
	for {
		switch p.rune(false) {
		case eof:
			p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
			return nil, nil
		case rune(ANDAND):
			s = &BinaryExpression{Lhs: r, Op: BinaryOperationLAnd, Token: p.shift(false)}
			s.Rhs, _ = p.inclusiveOrExpression(checkTypeName)
		default:
			return r, u
		}
		r = s
		u = nil
	}
}

// [0], 6.5.12 Bitwise inclusive OR operator
//
//  inclusive-OR-expression:
// 	exclusive-OR-expression
// 	inclusive-OR-expression | exclusive-OR-expression
func (p *parser) inclusiveOrExpression(checkTypeName bool) (r, u Expression) {
	r, u = p.exclusiveOrExpression(checkTypeName)
	var s *BinaryExpression
	for {
		switch p.rune(false) {
		case eof:
			p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
			return nil, nil
		case '|':
			s = &BinaryExpression{Lhs: r, Op: BinaryOperationOr, Token: p.shift(false)}
			s.Rhs, _ = p.exclusiveOrExpression(checkTypeName)
		default:
			return r, u
		}
		r = s
		u = nil
	}
}

// [0], 6.5.11 Bitwise exclusive OR operator
//
//  exclusive-OR-expression:
// 	AND-expression
// 	exclusive-OR-expression ^ AND-expression
func (p *parser) exclusiveOrExpression(checkTypeName bool) (r, u Expression) {
	r, u = p.andExpression(checkTypeName)
	var s *BinaryExpression
	for {
		switch p.rune(false) {
		case eof:
			p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
			return nil, nil
		case '^':
			s = &BinaryExpression{Lhs: r, Op: BinaryOperationXor, Token: p.shift(false)}
			s.Rhs, _ = p.andExpression(checkTypeName)
		default:
			return r, u
		}
		r = s
		u = nil
	}
}

// [0], 6.5.10 Bitwise AND operator
//
//  AND-expression:
// 	equality-expression
// 	AND-expression & equality-expression
func (p *parser) andExpression(checkTypeName bool) (r, u Expression) {
	r, u = p.equalityExpression(checkTypeName)
	var s *BinaryExpression
	for {
		switch p.rune(false) {
		case eof:
			p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
			return nil, nil
		case '&':
			s = &BinaryExpression{Lhs: r, Op: BinaryOperationAnd, Token: p.shift(false)}
			s.Rhs, _ = p.equalityExpression(checkTypeName)
		default:
			return r, u
		}
		r = s
		u = nil
	}
}

// [0], 6.5.9 Equality operators
//
//  equality-expression:
// 	relational-expression
// 	equality-expression == relational-expression
// 	equality-expression != relational-expression
func (p *parser) equalityExpression(checkTypeName bool) (r, u Expression) {
	r, u = p.relationalExpression(checkTypeName)
	var s *BinaryExpression
	for {
		switch p.rune(false) {
		case eof:
			p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
			return nil, nil
		case rune(EQ):
			s = &BinaryExpression{Lhs: r, Op: BinaryOperationEq, Token: p.shift(false)}
			s.Rhs, _ = p.relationalExpression(checkTypeName)
		case rune(NEQ):
			s = &BinaryExpression{Lhs: r, Op: BinaryOperationNeq, Token: p.shift(false)}
			s.Rhs, _ = p.relationalExpression(checkTypeName)
		default:
			return r, u
		}
		r = s
		u = nil
	}
}

// [0], 6.5.8 Relational operators
//
//  relational-expression:
// 	shift-expression
// 	relational-expression <  shift-expression
// 	relational-expression >  shift-expression
// 	relational-expression <= shift-expression
// 	relational-expression >= shift-expression
func (p *parser) relationalExpression(checkTypeName bool) (r, u Expression) {
	r, u = p.shiftExpression(checkTypeName)
	var s *BinaryExpression
	for {
		switch p.rune(false) {
		case eof:
			p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
			return nil, nil
		case '<':
			s = &BinaryExpression{Lhs: r, Op: BinaryOperationLt, Token: p.shift(false)}
			s.Rhs, _ = p.shiftExpression(checkTypeName)
		case '>':
			s = &BinaryExpression{Lhs: r, Op: BinaryOperationGt, Token: p.shift(false)}
			s.Rhs, _ = p.shiftExpression(checkTypeName)
		case rune(LEQ):
			s = &BinaryExpression{Lhs: r, Op: BinaryOperationLeq, Token: p.shift(false)}
			s.Rhs, _ = p.shiftExpression(checkTypeName)
		case rune(GEQ):
			s = &BinaryExpression{Lhs: r, Op: BinaryOperationGeq, Token: p.shift(false)}
			s.Rhs, _ = p.shiftExpression(checkTypeName)
		default:
			return r, u
		}
		r = s
		u = nil
	}
}

// [0], 6.5.7 Bitwise shift operators
//
//  shift-expression:
// 	additive-expression
// 	shift-expression << additive-expression
// 	shift-expression >> additive-expression
func (p *parser) shiftExpression(checkTypeName bool) (r, u Expression) {
	r, u = p.additiveExpression(checkTypeName)
	var s *BinaryExpression
	for {
		switch p.rune(false) {
		case eof:
			p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
			return nil, nil
		case rune(LSH):
			s = &BinaryExpression{Lhs: r, Op: BinaryOperationLsh, Token: p.shift(false)}
			s.Rhs, _ = p.additiveExpression(checkTypeName)
		case rune(RSH):
			s = &BinaryExpression{Lhs: r, Op: BinaryOperationRsh, Token: p.shift(false)}
			s.Rhs, _ = p.additiveExpression(checkTypeName)
		default:
			return r, u
		}
		r = s
		u = nil
	}
}

// [0], 6.5.6 Additive operators
//
//  additive-expression:
// 	multiplicative-expression
// 	additive-expression + multiplicative-expression
// 	additive-expression - multiplicative-expression
func (p *parser) additiveExpression(checkTypeName bool) (r, u Expression) {
	r, u = p.multiplicativeExpression(checkTypeName)
	var s *BinaryExpression
	for {
		switch op := p.rune(false); op {
		case eof:
			p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
			return nil, nil
		case '+':
			s = &BinaryExpression{Lhs: r, Op: BinaryOperationAdd, Token: p.shift(false)}
			s.Rhs, _ = p.multiplicativeExpression(checkTypeName)
		case '-':
			s = &BinaryExpression{Lhs: r, Op: BinaryOperationSub, Token: p.shift(false)}
			s.Rhs, _ = p.multiplicativeExpression(checkTypeName)
		default:
			return r, u
		}
		r = s
		u = nil
	}
}

// [0], 6.5.5 Multiplicative operators
//
//  multiplicative-expression:
// 	cast-expression
// 	multiplicative-expression * cast-expression
// 	multiplicative-expression / cast-expression
// 	multiplicative-expression % cast-expression
func (p *parser) multiplicativeExpression(checkTypeName bool) (r, u Expression) {
	r, u = p.castExpression(checkTypeName)
	var s *BinaryExpression
	for {
		switch p.rune(false) {
		case eof:
			p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
			return nil, nil
		case '*':
			s = &BinaryExpression{Lhs: r, Op: BinaryOperationMul, Token: p.shift(false)}
			s.Rhs, _ = p.castExpression(checkTypeName)
		case '/':
			s = &BinaryExpression{Lhs: r, Op: BinaryOperationDiv, Token: p.shift(false)}
			s.Rhs, _ = p.castExpression(checkTypeName)
		case '%':
			s = &BinaryExpression{Lhs: r, Op: BinaryOperationMod, Token: p.shift(false)}
			s.Rhs, _ = p.castExpression(checkTypeName)
		default:
			return r, u
		}
		r = s
		u = nil
	}
}

// [0], 6.5.4 Cast operators
//
//  cast-expression:
// 	unary-expression
// 	( type-name ) cast-expression
func (p *parser) castExpression(checkTypeName bool) (r, u Expression) {
	switch p.rune(false) {
	case eof:
		p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
		return nil, nil
	case '(':
		switch ch := p.peek(1, true).Ch; {
		case p.isSpecifierQualifer(ch, true) || ch == rune(ATTRIBUTE):
			lparen := p.shift(false)
			tn := p.typeName()
			rparen := p.must(')')
			switch p.rune(false) {
			case eof:
				p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
				return nil, nil
			case '{':
				u = p.unaryExpression(lparen, tn, rparen, checkTypeName)
				return u, u
			default:
				r := &CastExpression{Lparen: lparen, TypeName: tn, Rparen: rparen}
				r.Expr, _ = p.castExpression(checkTypeName)
				return r, nil
			}
		case p.isExpression(ch) || ch == '{':
			r = p.unaryExpression(Token{}, nil, Token{}, checkTypeName)
			return r, r
		}

		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected cast expression", t.Position(), runeName(t.Ch))
		return nil, nil
	default:
		r := p.unaryExpression(Token{}, nil, Token{}, checkTypeName)
		return r, r
	}
}

// [0], 6.7.6 Type names
//
//  type-name:
// 	specifier-qualifier-list abstract-declarator_opt
func (p *parser) typeName() *TypeName {
	return &TypeName{SpecifierQualifierList: p.specifierQualifierList(), AbstractDeclarator: p.abstractDeclarator(nil, true)}
}

//  abstract-declarator:
// 	pointer
// 	pointer_opt direct-abstract-declarator
func (p *parser) abstractDeclarator(ptr *Pointer, opt bool) *AbstractDeclarator {
	if ptr == nil {
		p.attributeSpecifierListOpt() //TODO not stored yet
		ptr = p.pointer(true)
	}
	switch {
	case ptr == nil:
		switch p.rune(false) {
		case
			')',
			':':

			if opt {
				return nil
			}

			t := p.shift(false)
			p.cpp.eh("%v: unexpected %v, expected abstract declarator", t.Position(), runeName(t.Ch))
			return nil
		case '[':
			return &AbstractDeclarator{Case: AbstractDeclaratorDecl, DirectAbstractDeclarator: p.directAbstractDeclarator()}
		case '(':
			switch p.peek(1, true).Ch {
			case
				'*',
				rune(ATTRIBUTE):

				return &AbstractDeclarator{Case: AbstractDeclaratorPtr, DirectAbstractDeclarator: p.directAbstractDeclarator()}
			default:
				t := p.shift(false)
				p.cpp.eh("%v: unexpected %v, expected abstract declarator", t.Position(), runeName(t.Ch))
				return nil
			}
		default:
			switch p.rune(true) {
			case rune(IDENTIFIER):
				t := p.shift(true)
				p.cpp.eh("%v: unexpected %v, expected ';'", t.Position(), runeName(t.Ch))
				return nil
			default:
				t := p.shift(false)
				p.cpp.eh("%v: unexpected %v, expected abstract declarator", t.Position(), runeName(t.Ch))
				return nil
			}
		}
	default:
		switch p.rune(false) {
		case
			')',
			':':

			return &AbstractDeclarator{Case: AbstractDeclaratorPtr, Pointer: ptr}
		case '[':
			return &AbstractDeclarator{Case: AbstractDeclaratorDecl, Pointer: ptr, DirectAbstractDeclarator: p.directAbstractDeclarator()}
		case '(':
			switch ch := p.peek(1, true).Ch; {
			case ch == '*' || p.isDeclarationSpecifier(ch, true):
				return &AbstractDeclarator{Case: AbstractDeclaratorPtr, Pointer: ptr, DirectAbstractDeclarator: p.directAbstractDeclarator()}
			default:
				t := p.shift(false)
				p.cpp.eh("%v: unexpected %v, expected abstract declarator", t.Position(), runeName(t.Ch))
				return nil
			}
		default:
			t := p.shift(false)
			p.cpp.eh("%v: unexpected %v, expected abstract declarator", t.Position(), runeName(t.Ch))
			return nil
		}
	}
}

//  direct-abstract-declarator:
// 	( abstract-declarator )
// 	direct-abstract-declarator_opt [ type-qualifier-list_opt assignment-expression_opt ]
// 	direct-abstract-declarator_opt [ static type-qualifier-list_opt assignment-expression ]
// 	direct-abstract-declarator_opt [ type-qualifier-list static assignment-expression ]
// 	direct-abstract-declarator_opt [ * ]
// 	direct-abstract-declarator_opt ( parameter-type-list_opt )
func (p *parser) directAbstractDeclarator() (r *DirectAbstractDeclarator) {
out:
	switch p.rune(false) {
	case '[':
		switch ch := p.peek(1, false).Ch; {
		case p.isTypeQualifier(ch):
			lbracket := p.shift(false)
			tql := p.typeQualifierList(false, false)
			switch p.rune(false) {
			case eof:
				p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
				return nil
			case rune(INTCONST):
				r = &DirectAbstractDeclarator{Case: DirectAbstractDeclaratorArr, Token: lbracket, TypeQualifiers: tql, Expression: p.assignmentExpression(true), Token2: p.must(']')}
				break out
			case rune(STATIC):
				r = &DirectAbstractDeclarator{Case: DirectAbstractDeclaratorArr, Token: lbracket, TypeQualifiers: tql, Token2: p.shift(false), Expression: p.assignmentExpression(true), Token3: p.must(']')}
				break out
			default:
				t := p.shift(false)
				p.cpp.eh("%v: unexpected %v, expected direct abstract declarator", t.Position(), runeName(t.Ch))
			}
		case ch != '*' && p.isExpression(ch):
			r = &DirectAbstractDeclarator{Case: DirectAbstractDeclaratorArr, Token: p.shift(false), Expression: p.assignmentExpression(true), Token2: p.must(']')}
			break out
		}

		switch p.peek(1, false).Ch {
		case ']':
			r = &DirectAbstractDeclarator{Case: DirectAbstractDeclaratorArr, Token: p.shift(false), Token2: p.shift(false)}
		case rune(STATIC):
			lbracket := p.shift(false)
			switch {
			case p.isTypeQualifier(p.peek(1, false).Ch):
				r = &DirectAbstractDeclarator{Case: DirectAbstractDeclaratorStaticArr, Token: lbracket, Token2: p.shift(false), TypeQualifiers: p.typeQualifierList(false, false), Expression: p.assignmentExpression(true), Token3: p.must(']')}
			default:
				t := p.shift(false)
				p.cpp.eh("%v: unexpected %v, expected direct abstract declarator", t.Position(), runeName(t.Ch))
			}
		case '*':
			switch p.peek(2, false).Ch {
			case ']':
				r = &DirectAbstractDeclarator{Case: DirectAbstractDeclaratorArrStar, Token: p.shift(false), Token2: p.shift(false), Token3: p.shift(false)}
			default:
				t := p.shift(false)
				p.cpp.eh("%v: unexpected %v, expected direct abstract declarator", t.Position(), runeName(t.Ch))
			}
		default:
			t := p.shift(false)
			p.cpp.eh("%v: unexpected %v, expected direct abstract declarator", t.Position(), runeName(t.Ch))
		}
	case '(':
		switch ch := p.peek(1, true).Ch; {
		case p.in(ch, '*', rune(ATTRIBUTE)):
			r = &DirectAbstractDeclarator{Case: DirectAbstractDeclaratorDecl, Token: p.shift(false), AbstractDeclarator: p.abstractDeclarator(nil, false), Token2: p.must(')')}
		case p.isDeclarationSpecifier(ch, true):
			p.newScope()

			func() {
				defer p.closeScope()
				r = &DirectAbstractDeclarator{Case: DirectAbstractDeclaratorFunc, Token: p.shift(false), ParameterTypeList: p.parameterTypeListOpt(), Token2: p.must(')'), params: p.scope}
			}()
		default:
			t := p.shift(false)
			p.cpp.eh("%v: unexpected %v, expected direct abstract declarator", t.Position(), runeName(t.Ch))
		}
	default:
		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected direct abstract declarator", t.Position(), runeName(t.Ch))
	}
	return p.directAbstractDeclarator2(r)
}

func (p *parser) directAbstractDeclarator2(dad *DirectAbstractDeclarator) (r *DirectAbstractDeclarator) {
	r = dad
	for {
		switch p.rune(false) {
		case eof:
			p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
			return nil
		case
			')',
			',',
			':':

			return r
		case '(':
			r = &DirectAbstractDeclarator{Case: DirectAbstractDeclaratorFunc, DirectAbstractDeclarator: r, Token: p.shift(false), ParameterTypeList: p.parameterTypeListOpt(), Token2: p.must(')')}
		case '[':
			ch := p.peek(1, true).Ch
			switch {
			case ch == ']':
				r = &DirectAbstractDeclarator{Case: DirectAbstractDeclaratorArr, DirectAbstractDeclarator: r, Token: p.shift(false), Token2: p.must(']')}
			case p.isExpression(ch):
				r = &DirectAbstractDeclarator{Case: DirectAbstractDeclaratorArr, DirectAbstractDeclarator: r, Token: p.shift(false), Expression: p.assignmentExpression(true), Token2: p.must(']')}
			default:
				t := p.shift(false)
				p.cpp.eh("%v: unexpected %v, expected direct abstract declarator", t.Position(), runeName(t.Ch))
			}
		default:
			t := p.shift(false)
			p.cpp.eh("%v: unexpected %v, expected direct abstract declarator", t.Position(), runeName(t.Ch))
		}
	}
}

//  specifier-qualifier-list:
// 	type-specifier specifier-qualifier-list_opt
// 	type-qualifier specifier-qualifier-list_opt
// 	alignment-specifier specifier-qualifier-list_opt
func (p *parser) specifierQualifierList() (r *SpecifierQualifierList) {
	var prev *SpecifierQualifierList
	acceptTypeName := true
	for {
		var sql *SpecifierQualifierList
		switch ch := p.rune(false); {
		case ch == rune(IDENTIFIER):
			if !acceptTypeName || !p.checkTypeName(&p.toks[0]) {
				return r
			}

			sql = &SpecifierQualifierList{Case: SpecifierQualifierListTypeSpec, TypeSpecifier: p.typeSpecifier()}
			acceptTypeName = false
		case ch == rune(ATOMIC) && p.peek(1, false).Ch == '(':
			sql = &SpecifierQualifierList{Case: SpecifierQualifierListTypeSpec, TypeSpecifier: p.typeSpecifier()}
			acceptTypeName = false
		case p.isTypeSpecifier(ch, false):
			sql = &SpecifierQualifierList{Case: SpecifierQualifierListTypeSpec, TypeSpecifier: p.typeSpecifier()}
			acceptTypeName = false
		case p.isTypeQualifier(ch) || ch == rune(ATTRIBUTE):
			sql = &SpecifierQualifierList{Case: SpecifierQualifierListTypeQual, TypeQualifier: p.typeQualifier(true)}
		case ch == rune(ALIGNAS):
			sql = &SpecifierQualifierList{Case: SpecifierQualifierListAlignSpec, AlignmentSpecifier: p.alignmentSpecifier()}
		default:
			return r
		}

		switch {
		case r == nil:
			r = sql
		default:
			prev.SpecifierQualifierList = sql
		}
		prev = sql
	}
}

func (p *parser) isSpecifierQualifer(ch rune, typenameOk bool) bool {
	return p.isTypeSpecifier(ch, typenameOk) || p.isTypeQualifier(ch)
}

// [0], 6.5.3 Unary operators
//
//  unary-expression:
// 	postfix-expression
// 	++ unary-expression
// 	-- unary-expression
// 	unary-operator cast-expression
// 	sizeof unary-expression
// 	sizeof ( type-name )
// 	&& identifier
// 	_Alignof unary-expression
// 	_Alignof ( type-name )
// 	__imag__ unary-expression
// 	__real__ unary-expression
//
//  unary-operator: one of
// 	& * + - ~ !
func (p *parser) unaryExpression(lp Token, tn *TypeName, rp Token, checkTypeName bool) Expression {
	if tn != nil {
		return p.postfixExpression(lp, tn, rp, checkTypeName)
	}

	var r *UnaryExpression
	switch p.rune(false) {
	case eof:
		p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
		return nil
	case '&':
		r = &UnaryExpression{Case: UnaryExpressionAddrof, Token: p.shift(false)}
		r.Expression, _ = p.castExpression(checkTypeName)
		return r
	case '*':
		r = &UnaryExpression{Case: UnaryExpressionDeref, Token: p.shift(false)}
		r.Expression, _ = p.castExpression(checkTypeName)
		return r
	case '+':
		r = &UnaryExpression{Case: UnaryExpressionPlus, Token: p.shift(false)}
		r.Expression, _ = p.castExpression(checkTypeName)
		return r
	case '-':
		r = &UnaryExpression{Case: UnaryExpressionMinus, Token: p.shift(false)}
		r.Expression, _ = p.castExpression(checkTypeName)
		return r
	case '~':
		r = &UnaryExpression{Case: UnaryExpressionCpl, Token: p.shift(false)}
		r.Expression, _ = p.castExpression(checkTypeName)
		return r
	case '!':
		r = &UnaryExpression{Case: UnaryExpressionNot, Token: p.shift(false)}
		r.Expression, _ = p.castExpression(checkTypeName)
		return r
	case rune(SIZEOF):
		switch p.peek(1, false).Ch {
		case '(':
			switch {
			case p.isSpecifierQualifer(p.peek(2, true).Ch, true):
				sz := p.shift(false)
				lp := p.shift(false)
				tn := p.typeName()
				rp := p.must(')')
				switch p.rune(false) {
				case '{':
					return &UnaryExpression{Case: UnaryExpressionSizeofExpr, Token: sz, Expression3: p.unaryExpression(lp, tn, rp, checkTypeName)}
				default:
					return &UnaryExpression{Case: UnaryExpressionSizeofType, Token: sz, Token2: lp, TypeName: tn, Token3: rp}
				}
			default:
				return &UnaryExpression{Case: UnaryExpressionSizeofExpr, Token: p.shift(false), Expression3: p.unaryExpression(Token{}, nil, Token{}, checkTypeName)}
			}
		default:
			return &UnaryExpression{Case: UnaryExpressionSizeofExpr, Token: p.shift(false), Expression3: p.unaryExpression(Token{}, nil, Token{}, checkTypeName)}
		}
	case
		'(',
		rune(CHARCONST),
		rune(FLOATCONST),
		rune(GENERIC),
		rune(IDENTIFIER),
		rune(INTCONST),
		rune(LONGCHARCONST),
		rune(LONGSTRINGLITERAL),
		rune(STRINGLITERAL):

		return p.postfixExpression(Token{}, nil, Token{}, checkTypeName)
	case rune(INC):
		return &UnaryExpression{Case: UnaryExpressionInc, Token: p.shift(false), Expression3: p.unaryExpression(Token{}, nil, Token{}, checkTypeName)}
	case rune(DEC):
		return &UnaryExpression{Case: UnaryExpressionDec, Token: p.shift(false), Expression3: p.unaryExpression(Token{}, nil, Token{}, checkTypeName)}
	case rune(ALIGNOF):
		switch p.peek(1, false).Ch {
		case '(':
			switch {
			case p.isSpecifierQualifer(p.peek(2, true).Ch, true):
				return &UnaryExpression{Case: UnaryExpressionAlignofType, Token: p.shift(false), Token2: p.shift(false), TypeName: p.typeName(), Token3: p.must(')')}
			default:
				return &UnaryExpression{Case: UnaryExpressionAlignofExpr, Token: p.shift(false), Expression3: p.unaryExpression(Token{}, nil, Token{}, checkTypeName)}
			}
		default:
			t := p.shift(false)
			p.cpp.eh("%v: unexpected %v, expected unary expression or (type name)", t.Position(), runeName(t.Ch))
			return nil
		}
	case rune(ANDAND):
		return &UnaryExpression{Case: UnaryExpressionLabelAddr, Token: p.shift(false), Token2: p.must(rune(IDENTIFIER))}
	case rune(REAL):
		return &UnaryExpression{Case: UnaryExpressionReal, Token: p.shift(false), Expression3: p.unaryExpression(Token{}, nil, Token{}, checkTypeName)}
	case rune(IMAG):
		return &UnaryExpression{Case: UnaryExpressionImag, Token: p.shift(false), Expression3: p.unaryExpression(Token{}, nil, Token{}, checkTypeName)}
	default:
		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected unary expression", t.Position(), runeName(t.Ch))
		return nil
	}
}

// [0], 6.5.2 Postfix operators
//
//  postfix-expression:
// 	primary-expression
// 	postfix-expression [ expression ]
// 	postfix-expression ( argument-expression-list_opt )
// 	postfix-expression . identifier
// 	postfix-expression -> identifier
// 	postfix-expression ++
// 	postfix-expression --
// 	( type-name ) { initializer-list }
// 	( type-name ) { initializer-list , }
// 	__builtin_types_compatible_p ( type-name , type-name )
func (p *parser) postfixExpression(lp Token, tn *TypeName, rp Token, checkTypeName bool) (r Expression) {
	var r0 *PostfixExpression
	switch {
	case tn != nil:
		r0 = &PostfixExpression{Case: PostfixExpressionComplit, Token: lp, TypeName: tn, Token2: rp, Token3: p.must('{'), InitializerList: p.initializerList(nil)}
		switch p.rune(false) {
		case eof:
			p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
			return nil
		case ',':
			r0.Token4 = p.shift(false)
			fallthrough
		default:
			r0.Token5 = p.must('}')
		}
	default:
		switch p.rune(false) {
		case eof:
			p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
			return nil
		case '(':
			switch ch := p.peek(1, true).Ch; {
			case p.isExpression(ch) || ch == '{':
				r0 = &PostfixExpression{Case: PostfixExpressionPrimary, Expression2: p.primaryExpression(checkTypeName)}
			case p.isSpecifierQualifer(ch, true):
				r0 = &PostfixExpression{Case: PostfixExpressionComplit, Token: p.shift(false), TypeName: p.typeName(), Token2: p.must(')'), Token3: p.must('{'), InitializerList: p.initializerList(nil)}
				switch p.rune(false) {
				case eof:
					p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
					return nil
				case ',':
					r0.Token4 = p.shift(false)
					fallthrough
				default:
					r0.Token5 = p.must('}')
					return r0
				}
			default:
				t := p.shift(false)
				p.cpp.eh("%v: unexpected %v, expected postfix expression", t.Position(), runeName(t.Ch))
				return nil
			}
		default:
			r0 = &PostfixExpression{Case: PostfixExpressionPrimary, Expression2: p.primaryExpression(checkTypeName)}
		}
	}
	r = r0
	if r0.Case == PostfixExpressionPrimary && r0.Expression2 != nil {
		r = r0.Expression2
	}
	for {
		switch p.rune(false) {
		case eof:
			p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
			return nil
		case '[':
			r = &PostfixExpression{Case: PostfixExpressionIndex, Expression: r, Token: p.shift(false), ExpressionList: p.expression(false), Token2: p.must(']')}
		case '(':
			switch ch := p.peek(1, true).Ch; {
			case p.isExpression(ch) || ch == ')':
				r = &PostfixExpression{Case: PostfixExpressionCall, Expression: r, Token: p.shift(false), ArgumentExpressionList: p.argumentExpressionListOpt(true), Token2: p.must(')')}
			default:
				t := p.shift(false)
				p.cpp.eh("%v: unexpected %v, expected postfix expression", t.Position(), runeName(t.Ch))
			}
		case '.':
			r = &PostfixExpression{Case: PostfixExpressionSelect, Expression: r, Token: p.shift(false), Token2: p.must(rune(IDENTIFIER))}
		case rune(ARROW):
			r = &PostfixExpression{Case: PostfixExpressionPSelect, Expression: r, Token: p.shift(false), Token2: p.must(rune(IDENTIFIER))}
		case rune(INC):
			r = &PostfixExpression{Case: PostfixExpressionInc, Expression: r, Token: p.shift(false)}
		case rune(DEC):
			r = &PostfixExpression{Case: PostfixExpressionDec, Expression: r, Token: p.shift(false)}
		default:
			return r
		}
	}
}

//  argument-expression-list:
// 	assignment-expression
// 	argument-expression-list , assignment-expression
func (p *parser) argumentExpressionListOpt(checkTypeName bool) (r *ArgumentExpressionList) {
	p.rune(false)
	switch p.rune(false) {
	case eof:
		p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
		return nil
	case ')':
		return nil
	}

	r = &ArgumentExpressionList{Expression: p.assignmentExpression(checkTypeName)}
	prev := r
	for p.rune(false) == ',' {
		ael := &ArgumentExpressionList{Token: p.shift(false), Expression: p.assignmentExpression(checkTypeName)}
		prev.ArgumentExpressionList = ael
		prev = ael
		p.rune(false)
	}
	p.rune(false)
	return r
}

// [0], 6.5.1 Primary expressions
//
//  primary-expression:
// 	identifier
// 	constant
// 	string-literal
// 	( expression )
// 	( compound-statement )
//	generic-selection
func (p *parser) primaryExpression(checkTypeName bool) (r *PrimaryExpression) {
	switch p.rune(checkTypeName) {
	case eof:
		p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
		return nil
	case rune(CHARCONST):
		r = &PrimaryExpression{Case: PrimaryExpressionChar, Token: p.shift(false)}
	case rune(FLOATCONST):
		r = &PrimaryExpression{Case: PrimaryExpressionFloat, Token: p.shift(false)}
	case rune(IDENTIFIER):
		r = &PrimaryExpression{Case: PrimaryExpressionIdent, Token: p.shift(false), lexicalScope: (*lexicalScope)(p.scope)}
	case rune(INTCONST):
		r = &PrimaryExpression{Case: PrimaryExpressionInt, Token: p.shift(false)}
	case rune(LONGCHARCONST):
		r = &PrimaryExpression{Case: PrimaryExpressionLChar, Token: p.shift(false)}
	case rune(LONGSTRINGLITERAL):
		r = &PrimaryExpression{Case: PrimaryExpressionLString, Token: p.shift(false)}
	case rune(STRINGLITERAL):
		r = &PrimaryExpression{Case: PrimaryExpressionString, Token: p.shift(false)}
	case '(':
		switch p.peek(1, false).Ch {
		case '{':
			return &PrimaryExpression{Case: PrimaryExpressionStmt, Token: p.shift(false), CompoundStatement: p.compoundStatement(false, nil), Token2: p.must(')')}
		default:
			return &PrimaryExpression{Case: PrimaryExpressionExpr, Token: p.shift(false), ExpressionList: p.expression(false), Token2: p.must(')')}
		}
	case rune(GENERIC):
		return &PrimaryExpression{Case: PrimaryExpressionGeneric, GenericSelection: p.genericSelection()}
	default:
		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected primary expression", t.Position(), runeName(t.Ch))
		return nil
	}
	r.m = p.cpp.mmap[mmapKey{r.Token.s, r.Token.off}]
	return r
}

// generic-selection:
//	_Generic ( assignment-expression , generic-assoc-list )
func (p *parser) genericSelection() (r *GenericSelection) {
	return &GenericSelection{Token: p.must(rune(GENERIC)), Token2: p.must('('), Expression: p.assignmentExpression(true), Token3: p.must(','), GenericAssociationList: p.genericAssociationList(), Token4: p.must(')')}
}

// generic-assoc-list:
// 	generic-association
// 	generic-assoc-list , generic-association
func (p *parser) genericAssociationList() (r *GenericAssociationList) {
	r = &GenericAssociationList{GenericAssociation: p.genericAssociation()}
	prev := r
	for p.rune(false) == ',' {
		gal := &GenericAssociationList{Token: p.shift(false), GenericAssociation: p.genericAssociation()}
		prev.GenericAssociationList = gal
		prev = gal
	}
	return r
}

// generic-association:
//	type-name : assignment-expression
//	default : assignment-expression
func (p *parser) genericAssociation() (r *GenericAssociation) {
	switch {
	case p.rune(false) == rune(DEFAULT):
		return &GenericAssociation{Case: GenericAssociationDefault, Token: p.shift(false), Token2: p.must(':'), Expression: p.assignmentExpression(true)}
	default:
		return &GenericAssociation{Case: GenericAssociationType, TypeName: p.typeName(), Token: p.must(':'), Expression: p.assignmentExpression(true)}
	}
}

// [0], 6.7.5 Declarators
//
//  declarator:
// 	pointer_opt direct-declarator
func (p *parser) declarator(ptr *Pointer, ds DeclarationSpecifiers, declare bool) (r *Declarator) {
	if ptr == nil {
		ptr = p.pointer(true)
	}
	r = &Declarator{Pointer: ptr, DirectDeclarator: p.directDeclarator(declare), lexicalScope: (*lexicalScope)(p.scope), isTypename: ds.IsTypedef()}
	if declare {
		r.visible = visible(p.seq) // [0]6.2.1,7
		p.scope.declare(p.cpp.eh, r.Name(), r)
	}
	return r
}

//  direct-declarator:
// 	identifier
// 	( declarator )
// 	direct-declarator [ type-qualifier-list_opt assignment-expression_opt ]
// 	direct-declarator [ static type-qualifier-list_opt assignment-expression ]
// 	direct-declarator [ type-qualifier-list static assignment-expression ]
// 	direct-declarator [ type-qualifier-list_opt * ]
// 	direct-declarator ( parameter-type-list_opt )
// 	direct-declarator ( identifier-list_opt )
func (p *parser) directDeclarator(declare bool) (r *DirectDeclarator) {
	switch p.rune(false) {
	case rune(IDENTIFIER):
		r = &DirectDeclarator{Case: DirectDeclaratorIdent, Token: p.shift(false)}
	case '(':
		r = &DirectDeclarator{Case: DirectDeclaratorDecl, Token: p.shift(false)}
		p.attributeSpecifierListOpt() //TODO not stored yet
		r.Declarator = p.declarator(nil, nil, false)
		r.Token2 = p.must(')')
	default:
		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected direct declarator", t.Position(), runeName(t.Ch))
	}
	return p.directDeclarator2(r, declare)
}

func (p *parser) directDeclarator2(dd *DirectDeclarator, declare bool) (r *DirectDeclarator) {
	r = dd
	for {
		switch p.rune(false) {
		case '(':
			p.newScope()

			func() {
				defer p.closeScope()

				switch p.peek(1, true).Ch {
				case rune(IDENTIFIER):
					r = &DirectDeclarator{Case: DirectDeclaratorFuncIdent, DirectDeclarator: r, Token: p.shift(false), IdentifierList: p.identifierList(true), Token2: p.must(')')}
				default:
					r = &DirectDeclarator{Case: DirectDeclaratorFuncParam, DirectDeclarator: r, Token: p.shift(false), ParameterTypeList: p.parameterTypeListOpt(), Token2: p.must(')')}
				}
				r.params = p.scope
			}()
		case '[':
			ch := p.peek(1, true).Ch
			switch {
			case p.isExpression(ch):
				r = &DirectDeclarator{Case: DirectDeclaratorArr, DirectDeclarator: r, Token: p.shift(false), Expression: p.assignmentExpression(true), Token2: p.must(']')}
				continue
			case p.isTypeQualifier(ch):
				lbracket := p.shift(false)
				tql := p.typeQualifierList(false, false)
				switch p.rune(false) {
				case rune(STATIC):
					r = &DirectDeclarator{Case: DirectDeclaratorArrStatic, DirectDeclarator: r, Token: lbracket, TypeQualifiers: tql, Token2: p.shift(false), Expression: p.assignmentExpression(true), Token3: p.must(']')}
				case '*':
					r = &DirectDeclarator{Case: DirectDeclaratorStar, DirectDeclarator: r, Token: lbracket, TypeQualifiers: tql, Token2: p.shift(false), Token3: p.must(']')}
				case ']':
					r = &DirectDeclarator{Case: DirectDeclaratorArr, DirectDeclarator: r, Token: lbracket, TypeQualifiers: tql, Token3: p.must(']')}
				default:
					r = &DirectDeclarator{Case: DirectDeclaratorArr, DirectDeclarator: r, Token: lbracket, TypeQualifiers: tql, Expression: p.assignmentExpression(true), Token3: p.must(']')}
				}
				continue
			}

			switch ch {
			case ']':
				r = &DirectDeclarator{Case: DirectDeclaratorArr, DirectDeclarator: r, Token: p.shift(false), Token2: p.shift(false)}
			case rune(STATIC):
				r = &DirectDeclarator{Case: DirectDeclaratorStaticArr, DirectDeclarator: r, Token: p.shift(false), Token2: p.shift(false), TypeQualifiers: p.typeQualifierList(true, false), Expression: p.assignmentExpression(true), Token3: p.must(']')}
			default:
				t := p.shift(false)
				p.cpp.eh("%v: unexpected %v, expected direct declarator", t.Position(), runeName(t.Ch))
			}
		default:
			return r
		}
	}
	return r
}

//  identifier-list:
// 	identifier
// 	identifier-list , identifier
func (p *parser) identifierList(declare bool) (r *IdentifierList) {
	switch p.rune(true) {
	case eof:
		p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
		return nil
	case rune(IDENTIFIER):
		r = &IdentifierList{Token2: p.shift(false)}
		if declare {
			param := &Parameter{name: r.Token2, visible: visible(r.Token2.seq)}
			p.scope.declare(p.cpp.eh, r.Token2.SrcStr(), param)
			r.parameters = append(r.parameters, param)
		}
	default:
		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected identifier", t.Position(), runeName(t.Ch))
		return nil
	}

	r0 := r
	prev := r
	for p.rune(false) == ',' {
		il := &IdentifierList{Token: p.shift(false), Token2: p.must(rune(IDENTIFIER))}
		if declare {
			param := &Parameter{name: il.Token2, visible: visible(il.Token2.seq)}
			p.scope.declare(p.cpp.eh, il.Token2.SrcStr(), param)
			r0.parameters = append(r0.parameters, param)
		}
		prev.IdentifierList = il
		prev = il
	}
	return r
}

//  parameter-type-list:
// 	parameter-list
// 	parameter-list , ...
func (p *parser) parameterTypeListOpt() (r *ParameterTypeList) {
	switch p.rune(false) {
	case eof:
		p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
		return nil
	case ')':
		return nil
	}

	pl := p.parameterList()
	switch p.rune(false) {
	case eof:
		p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
		return nil
	case ',':
		return &ParameterTypeList{Case: ParameterTypeListVar, ParameterList: pl, Token: p.shift(false), Token2: p.must(rune(DDD))}
	default:
		return &ParameterTypeList{Case: ParameterTypeListList, ParameterList: pl}
	}
}

//  parameter-list:
// 	parameter-declaration
// 	parameter-list , parameter-declaration
func (p *parser) parameterList() (r *ParameterList) {
	r = &ParameterList{ParameterDeclaration: p.parameterDeclaration()}
	prev := r
	for p.rune(false) == ',' {
		if p.peek(1, false).Ch == rune(DDD) {
			return r
		}

		pl := &ParameterList{Token: p.shift(false), ParameterDeclaration: p.parameterDeclaration()}
		prev.ParameterList = pl
		prev = pl
	}
	return r
}

//  parameter-declaration:
// 	declaration-specifiers declarator
// 	declaration-specifiers abstract-declarator_opt
func (p *parser) parameterDeclaration() (r *ParameterDeclaration) {
	ds, ok := p.declarationSpecifiers()
	if !ok {
		return nil
	}

	switch p.rune(false) {
	case
		')',
		',':

		return &ParameterDeclaration{Case: ParameterDeclarationAbstract, DeclarationSpecifiers: ds}
	default:
		switch x := p.declaratorOrAbstractDeclarator(true).(type) {
		case *AbstractDeclarator:
			return &ParameterDeclaration{Case: ParameterDeclarationAbstract, DeclarationSpecifiers: ds, AbstractDeclarator: x}
		case *Declarator:
			return &ParameterDeclaration{Case: ParameterDeclarationDecl, DeclarationSpecifiers: ds, Declarator: x, AttributeSpecifiers: p.attributeSpecifierListOpt()}
		default:
			t := p.shift(false)
			p.cpp.eh("%v: unexpected %v, expected parameter declaration", t.Position(), runeName(t.Ch))
			return nil
		}
	}
}

func (p *parser) declaratorOrAbstractDeclarator(declare bool) (r Node) {
	// state 2
	ptr0 := p.pointer(true)
	switch p.rune(false) {
	case
		')',
		',':

		if ptr0 != nil {
			return &AbstractDeclarator{Case: AbstractDeclaratorPtr, Pointer: ptr0}
		}

		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected declarator or abstract declarator", t.Position(), runeName(t.Ch))
		return nil
	case '(':
		lparen := p.shift(false)
		p.attributeSpecifierListOpt() //TODO not stored yet
		if p.isSpecifierQualifer(p.rune(true), true) {
			dad := &DirectAbstractDeclarator{Case: DirectAbstractDeclaratorFunc, Token: lparen, ParameterTypeList: p.parameterTypeListOpt(), Token2: p.must(')')}
			switch {
			case p.in(p.rune(false), ',', ')'):
				return &AbstractDeclarator{Case: AbstractDeclaratorDecl, Pointer: ptr0, DirectAbstractDeclarator: dad}
			default:
				t := p.shift(false)
				p.cpp.eh("%v: unexpected %v, expected declarator or abstract declarator", t.Position(), runeName(t.Ch))
				return nil
			}
		}

		switch p.rune(true) {
		case ')':
			dad := &DirectAbstractDeclarator{Case: DirectAbstractDeclaratorFunc, Token: lparen, Token2: p.shift(false)}
			return &AbstractDeclarator{Case: AbstractDeclaratorDecl, Pointer: ptr0, DirectAbstractDeclarator: p.directAbstractDeclarator2(dad)}
		case '(':
			switch x := p.declaratorOrAbstractDeclarator(false).(type) {
			case *AbstractDeclarator:
				dad := &DirectAbstractDeclarator{
					Case:               DirectAbstractDeclaratorDecl,
					Token:              lparen,
					AbstractDeclarator: x,
					Token2:             p.must(')'),
				}
				return &AbstractDeclarator{Case: AbstractDeclaratorDecl, Pointer: ptr0, DirectAbstractDeclarator: p.directAbstractDeclarator2(dad)}
			case *Declarator:
				dd := &DirectDeclarator{
					Case:       DirectDeclaratorDecl,
					Token:      lparen,
					Declarator: x,
					Token2:     p.must(')'),
				}
				r := &Declarator{Pointer: ptr0, DirectDeclarator: p.directDeclarator2(dd, declare)}
				if declare {
					r.visible = visible(p.seq) // [0]6.2.1,7
					p.scope.declare(p.cpp.eh, r.Name(), r)
				}
				return r
			default:
				t := p.shift(false)
				p.cpp.eh("%v: unexpected %v, expected declarator or abstract declarator", t.Position(), runeName(t.Ch))
				return nil
			}
		case rune(IDENTIFIER):
			dd := p.directDeclarator(declare)
			switch p.rune(false) {
			case ')':
				dd = &DirectDeclarator{
					Case:  DirectDeclaratorDecl,
					Token: lparen,
					Declarator: &Declarator{
						DirectDeclarator: dd,
					},
					Token2: p.must(')'),
				}
				r := &Declarator{Pointer: ptr0, DirectDeclarator: p.directDeclarator2(dd, declare)}
				if declare {
					r.visible = visible(p.seq) // [0]6.2.1,7
					p.scope.declare(p.cpp.eh, r.Name(), r)
				}
				return r
			default:
				t := p.shift(false)
				p.cpp.eh("%v: unexpected %v, expected declarator or abstract declarator", t.Position(), runeName(t.Ch))
				return nil
			}
		case '*':
			ptr := p.pointer(false)
			switch p.rune(false) {
			case
				')',
				'[':

				dad := &DirectAbstractDeclarator{
					Case:               DirectAbstractDeclaratorDecl,
					Token:              lparen,
					AbstractDeclarator: p.abstractDeclarator(ptr, false),
					Token2:             p.must(')'),
				}
				return &AbstractDeclarator{Case: AbstractDeclaratorDecl, Pointer: ptr0, DirectAbstractDeclarator: p.directAbstractDeclarator2(dad)}
			case rune(IDENTIFIER):
				dd := p.directDeclarator(declare)
				switch p.rune(false) {
				case ')':
					dd = &DirectDeclarator{
						Case:  DirectDeclaratorDecl,
						Token: lparen,
						Declarator: &Declarator{
							Pointer:          ptr,
							DirectDeclarator: dd,
						},
						Token2: p.must(')'),
					}
					r := &Declarator{Pointer: ptr0, DirectDeclarator: p.directDeclarator2(dd, declare)}
					if declare {
						r.visible = visible(p.seq) // [0]6.2.1,7
						p.scope.declare(p.cpp.eh, r.Name(), r)
					}
					return r
				default:
					t := p.shift(false)
					p.cpp.eh("%v: unexpected %v, expected declarator or abstract declarator", t.Position(), runeName(t.Ch))
					return nil
				}
			case '(':
				switch x := p.declaratorOrAbstractDeclarator(false).(type) {
				case *Declarator:
					x.Pointer = ptr
					dd := &DirectDeclarator{Case: DirectDeclaratorDecl, Token: lparen, Declarator: x, Token2: p.must(')')}
					r := &Declarator{Pointer: ptr0, DirectDeclarator: dd}
					if declare {
						r.visible = visible(p.seq) // [0]6.2.1,7
						p.scope.declare(p.cpp.eh, r.Name(), r)
					}
					return r
				default:
					t := p.shift(false)
					p.cpp.eh("%v: unexpected %v, expected declarator or abstract declarator", t.Position(), runeName(t.Ch))
					return nil
				}
			default:
				t := p.shift(false)
				p.cpp.eh("%v: unexpected %v, expected declarator or abstract declarator", t.Position(), runeName(t.Ch))
				return nil
			}
		case '^':
			ptr := p.pointer(false)
			switch p.rune(false) {
			case ')':
				dad := &DirectAbstractDeclarator{
					Case:               DirectAbstractDeclaratorDecl,
					Token:              lparen,
					AbstractDeclarator: p.abstractDeclarator(ptr, false),
					Token2:             p.must(')'),
				}
				return &AbstractDeclarator{Case: AbstractDeclaratorDecl, Pointer: ptr0, DirectAbstractDeclarator: p.directAbstractDeclarator2(dad)}
			case rune(IDENTIFIER):
				dd := p.directDeclarator(declare)
				switch p.rune(false) {
				case ')':
					dd = &DirectDeclarator{
						Case:  DirectDeclaratorDecl,
						Token: lparen,
						Declarator: &Declarator{
							Pointer:          ptr,
							DirectDeclarator: dd,
						},
						Token2: p.must(')'),
					}
					r := &Declarator{Pointer: ptr0, DirectDeclarator: p.directDeclarator2(dd, declare)}
					if declare {
						r.visible = visible(p.seq) // [0]6.2.1,7
						p.scope.declare(p.cpp.eh, r.Name(), r)
					}
					return r
				default:
					t := p.shift(false)
					p.cpp.eh("%v: unexpected %v, expected declarator or abstract declarator", t.Position(), runeName(t.Ch))
					return nil
				}
			default:
				t := p.shift(false)
				p.cpp.eh("%v: unexpected %v, expected declarator or abstract declarator", t.Position(), runeName(t.Ch))
				return nil
			}
		case '[':
			dad := &DirectAbstractDeclarator{
				Case:               DirectAbstractDeclaratorDecl,
				Token:              lparen,
				AbstractDeclarator: p.abstractDeclarator(nil, false),
				Token2:             p.must(')'),
			}
			return &AbstractDeclarator{Case: AbstractDeclaratorDecl, Pointer: ptr0, DirectAbstractDeclarator: p.directAbstractDeclarator2(dad)}
		default:
			t := p.shift(false)
			p.cpp.eh("%v: unexpected %v, expected declarator or abstract declarator", t.Position(), runeName(t.Ch))
			return nil
		}
	case '[':
		return p.abstractDeclarator(ptr0, false)
	case rune(IDENTIFIER):
		return p.declarator(ptr0, nil, declare)
	default:
		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected declarator or abstract declarator", t.Position(), runeName(t.Ch))
		return nil
	}
}

func (p *parser) in(ch rune, set ...rune) bool {
	for _, v := range set {
		if ch == v {
			return true
		}
	}
	return false
}

//  type-qualifier-list:
// 	type-qualifier
// 	type-qualifier-list type-qualifier
// 	type-qualifier-list
func (p *parser) typeQualifierList(opt, acceptAttributes bool) (r []*TypeQualifier) {
	switch ch := p.rune(true); {
	case p.isTypeQualifier(ch):
		r = append(r, p.typeQualifier(false))
	case p.in(ch, ':', ')', ',', '[', ']', rune(STATIC)) || p.isExpression(ch) || ch == rune(TYPENAME):
		if opt {
			return nil
		}

		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected type qualifier", t.Position(), runeName(t.Ch))
	case ch == rune(ATTRIBUTE):
		if acceptAttributes {
			r = append(r, p.typeQualifier(true))
			break
		}

		fallthrough
	default:
		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected type qualifier", t.Position(), runeName(t.Ch))
	}
	for {
		switch ch := p.rune(false); {
		case p.in(ch, ':', ')', ',', '[', ']', rune(STATIC)) || p.isExpression(ch) || ch == rune(TYPENAME):
			return r
		case p.isTypeQualifier(ch):
			r = append(r, p.typeQualifier(acceptAttributes))
		default:
			t := p.shift(false)
			p.cpp.eh("%v: unexpected %v, expected type qualifier", t.Position(), runeName(t.Ch))
		}
	}
}

func (p *parser) isTypeQualifier(ch rune) bool {
	switch ch {
	case
		rune(ATOMIC),
		rune(CONST),
		rune(NONNULL),
		rune(RESTRICT),
		rune(VOLATILE):

		return true
	}
	return false
}

//  pointer:
// 	* type-qualifier-list_opt
// 	* type-qualifier-list_opt pointer
//      ^ type-qualifier-list_opt
func (p *parser) pointer(opt bool) (r *Pointer) {
	switch p.rune(false) {
	case eof:
		p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
		return nil
	case '*':
		r = &Pointer{Case: PointerTypeQual, Token: p.shift(false), TypeQualifiers: p.typeQualifierList(true, true)}
	case '^':
		return &Pointer{Case: PointerBlock, Token: p.shift(false), TypeQualifiers: p.typeQualifierList(true, true)}
	default:
		if opt {
			return nil
		}

		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected type pointer", t.Position(), runeName(t.Ch))
	}
	prev := r
	for p.rune(false) == '*' {
		p := p.pointer(false)
		prev.Pointer = p
		prev.Case = PointerPtr
		prev = p
	}
	return r
}

//  declaration-specifiers:
// 	storage-class-specifier declaration-specifiers_opt
// 	type-specifier declaration-specifiers_opt
// 	type-qualifier declaration-specifiers_opt
// 	function-specifier declaration-specifiers_opt
//	alignment-specifier declaration-specifiers_opt
func (p *parser) declarationSpecifiers() (r DeclarationSpecifiers, ok bool) {
	acceptTypeName := true
	for {
		var ds DeclarationSpecifier
		switch ch := p.rune(false); {
		case ch == eof:
			p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
			return nil, false
		case p.isTypeSpecifier(ch, false):
			ds = p.typeSpecifier()
			acceptTypeName = false
		case ch == rune(IDENTIFIER):
			if !acceptTypeName || !p.checkTypeName(&p.toks[0]) {
				return r, true
			}

			ds = p.typeSpecifier()
			acceptTypeName = false
		case ch == rune(ATOMIC):
			switch p.peek(1, false).Ch {
			case '(':
				ds = p.typeSpecifier()
				acceptTypeName = false
			default:
				ds = p.typeQualifier(false)
			}
		case p.isStorageClassSpecifier(ch):
			ds = p.storageClassSpecifier()
		case p.isTypeQualifier(ch):
			ds = p.typeQualifier(false)
		case p.in(ch, rune(INLINE), rune(NORETURN)):
			ds = p.functionSpecifier()
		case ch == rune(ATTRIBUTE):
			for _, a := range p.attributeSpecifierListOpt() {
				r = append(r, a)
			}
			continue
		case ch == rune(ALIGNAS):
			ds = p.alignmentSpecifier()
		default:
			return r, true
		}
		r = append(r, ds)
	}
}

func (p *parser) isDeclarationSpecifier(ch rune, typenameOk bool) bool {
	return p.isTypeSpecifier(ch, typenameOk) || p.isTypeQualifier(ch) || p.isStorageClassSpecifier(ch) ||
		ch == rune(ATTRIBUTE) || ch == rune(ALIGNAS) || p.isFunctionSpecifier(ch)
}

// [2], 6.7.5 Alignment specifier
//
// alignment-specifier:
// 	_Alignas ( type-name )
// 	_Alignas ( constant-expression )
func (p *parser) alignmentSpecifier() *AlignmentSpecifier {
	switch ch := p.peek(2, true).Ch; {
	case p.isTypeSpecifier(ch, true):
		return &AlignmentSpecifier{Case: AlignmentSpecifierType, Token: p.must(rune(ALIGNAS)), Token2: p.must('('), TypeName: p.typeName(), Token3: p.must(')')}
	case p.isExpression(ch):
		return &AlignmentSpecifier{Case: AlignmentSpecifierExpr, Token: p.must(rune(ALIGNAS)), Token2: p.must('('), Expression: p.constantExpression(), Token3: p.must(')')}
	default:
		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected alignment specifier", t.Position(), runeName(t.Ch))
		return nil
	}
}

// [0], 6.7.4 Function specifiers
//
//  function-specifier:
// 	inline
// 	_Noreturn
func (p *parser) functionSpecifier() *FunctionSpecifier {
	switch p.rune(false) {
	case eof:
		p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
		return nil
	case rune(INLINE):
		return &FunctionSpecifier{Case: FunctionSpecifierInline, Token: p.shift(false)}
	case rune(NORETURN):
		return &FunctionSpecifier{Case: FunctionSpecifierNoreturn, Token: p.shift(false)}
	default:
		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected function specifier", t.Position(), runeName(t.Ch))
		return nil
	}
}

func (p *parser) isFunctionSpecifier(ch rune) bool { return ch == rune(INLINE) || ch == rune(NORETURN) }

// [0], 6.7.3 Type qualifiers
//
//  type-qualifier:
// 	const
// 	restrict
// 	volatile
// 	_Atomic
//	__attribute__
func (p *parser) typeQualifier(acceptAttributes bool) *TypeQualifier {
	switch p.rune(false) {
	case eof:
		p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
		return nil
	case rune(CONST):
		return &TypeQualifier{Case: TypeQualifierConst, Token: p.shift(false)}
	case rune(RESTRICT):
		return &TypeQualifier{Case: TypeQualifierRestrict, Token: p.shift(false)}
	case rune(VOLATILE):
		return &TypeQualifier{Case: TypeQualifierVolatile, Token: p.shift(false)}
	case rune(ATOMIC):
		return &TypeQualifier{Case: TypeQualifierAtomic, Token: p.shift(false)}
	case rune(NONNULL):
		return &TypeQualifier{Case: TypeQualifierNonnull, Token: p.shift(false)}
	case rune(ATTRIBUTE):
		if acceptAttributes {
			return &TypeQualifier{Case: TypeQualifierAttr, AttributeSpecifiers: p.attributeSpecifierListOpt()}
		}

		fallthrough
	default:
		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected type qualifier", t.Position(), runeName(t.Ch))
		return nil
	}
}

// [0], 6.7.1 Storage-class specifiers
//
//  storage-class-specifier:
// 	typedef
// 	extern
// 	static
// 	auto
// 	register
//	__declspec ( ... )
func (p *parser) storageClassSpecifier() (r *StorageClassSpecifier) {
	switch p.rune(false) {
	case eof:
		p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
		return nil
	case rune(AUTO):
		return &StorageClassSpecifier{Case: StorageClassSpecifierAuto, Token: p.shift(false)}
	case rune(EXTERN):
		return &StorageClassSpecifier{Case: StorageClassSpecifierExtern, Token: p.shift(false)}
	case rune(REGISTER):
		return &StorageClassSpecifier{Case: StorageClassSpecifierRegister, Token: p.shift(false)}
	case rune(STATIC):
		return &StorageClassSpecifier{Case: StorageClassSpecifierStatic, Token: p.shift(false)}
	case rune(TYPEDEF):
		return &StorageClassSpecifier{Case: StorageClassSpecifierTypedef, Token: p.shift(false)}
	case rune(THREADLOCAL):
		return &StorageClassSpecifier{Case: StorageClassSpecifierThreadLocal, Token: p.shift(false)}
	case rune(DECLSPEC):
		r = &StorageClassSpecifier{Case: StorageClassSpecifierDeclspec, Token: p.shift(false), Token2: p.must('(')}
	out:
		for lvl := 0; ; {
			switch p.rune(false) {
			case '(':
				lvl++
			case ')':
				if lvl == 0 {
					break out
				}

				lvl--
			case eof:
				break out
			}
			r.Declspecs = append(r.Declspecs, p.shift(false))
		}
		r.Token3 = p.must(')')
		return r
	default:
		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected storage class specifier", t.Position(), runeName(t.Ch))
		return nil
	}
}

func (p *parser) isStorageClassSpecifier(ch rune) bool {
	switch ch {
	case
		rune(AUTO),
		rune(DECLSPEC),
		rune(EXTERN),
		rune(REGISTER),
		rune(STATIC),
		rune(THREADLOCAL),
		rune(TYPEDEF):

		return true
	}
	return false
}

// [0], 6.7.2 Type specifiers
//
//  type-specifier:
//	atomic-type-specifier
// 	_Bool
// 	_Complex
// 	_Decimal128
// 	_Decimal32
// 	_Decimal64
// 	_Float128
// 	_Float16
// 	_Float32
// 	_Float64
// 	__float80
// 	__fp16
// 	__m256d
// 	char
// 	double
// 	enum-specifier
// 	float
// 	int
// 	long
// 	short
// 	signed
// 	struct-or-union-specifier
// 	typedef-name
// 	typeof ( expression )
// 	typeof ( type-name )
// 	unsigned
// 	void
func (p *parser) typeSpecifier() *TypeSpecifier {
	switch p.rune(true) {
	case eof:
		p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
		return nil
	case rune(CHAR):
		return &TypeSpecifier{Case: TypeSpecifierChar, Token: p.shift(false)}
	case rune(DOUBLE):
		return &TypeSpecifier{Case: TypeSpecifierDouble, Token: p.shift(false)}
	case rune(ENUM):
		return &TypeSpecifier{Case: TypeSpecifierEnum, EnumSpecifier: p.enumSpecifier(), lexicalScope: (*lexicalScope)(p.scope)}
	case rune(FLOAT):
		return &TypeSpecifier{Case: TypeSpecifierFloat, Token: p.shift(false)}
	case rune(INT):
		return &TypeSpecifier{Case: TypeSpecifierInt, Token: p.shift(false)}
	case rune(LONG):
		return &TypeSpecifier{Case: TypeSpecifierLong, Token: p.shift(false)}
	case rune(SIGNED):
		return &TypeSpecifier{Case: TypeSpecifierSigned, Token: p.shift(false)}
	case rune(SHORT):
		return &TypeSpecifier{Case: TypeSpecifierShort, Token: p.shift(false)}
	case rune(TYPENAME):
		return &TypeSpecifier{Case: TypeSpecifierTypeName, Token: p.shift(true), lexicalScope: (*lexicalScope)(p.scope)}
	case rune(UNSIGNED):
		return &TypeSpecifier{Case: TypeSpecifierUnsigned, Token: p.shift(false)}
	case
		rune(STRUCT),
		rune(UNION):

		return &TypeSpecifier{Case: TypeSpecifierStructOrUnion, StructOrUnionSpecifier: p.structOrUnionSpecifier()}
	case rune(VOID):
		return &TypeSpecifier{Case: TypeSpecifierVoid, Token: p.shift(false)}
	case rune(BOOL):
		return &TypeSpecifier{Case: TypeSpecifierBool, Token: p.shift(false)}
	case rune(COMPLEX):
		return &TypeSpecifier{Case: TypeSpecifierComplex, Token: p.shift(false)}
	case rune(IMAGINARY):
		return &TypeSpecifier{Case: TypeSpecifierImaginary, Token: p.shift(false)}
	case rune(FLOAT16):
		return &TypeSpecifier{Case: TypeSpecifierFloat16, Token: p.shift(false)}
	case rune(FLOAT32):
		return &TypeSpecifier{Case: TypeSpecifierFloat32, Token: p.shift(false)}
	case rune(FLOAT32X):
		return &TypeSpecifier{Case: TypeSpecifierFloat32x, Token: p.shift(false)}
	case rune(FLOAT64):
		return &TypeSpecifier{Case: TypeSpecifierFloat64, Token: p.shift(false)}
	case rune(FLOAT64X):
		return &TypeSpecifier{Case: TypeSpecifierFloat64x, Token: p.shift(false)}
	case rune(FLOAT128):
		return &TypeSpecifier{Case: TypeSpecifierFloat128, Token: p.shift(false)}
	case rune(FLOAT128X):
		return &TypeSpecifier{Case: TypeSpecifierFloat128x, Token: p.shift(false)}
	case rune(ATOMIC):
		return &TypeSpecifier{Case: TypeSpecifierAtomic, AtomicTypeSpecifier: p.atomicTypeSpecifier()}
	case rune(UINT128):
		return &TypeSpecifier{Case: TypeSpecifierUint128, Token: p.shift(false)}
	case rune(INT128):
		return &TypeSpecifier{Case: TypeSpecifierInt128, Token: p.shift(false)}
	case rune(DECIMAL32):
		return &TypeSpecifier{Case: TypeSpecifierDecimal32, Token: p.shift(false)}
	case rune(DECIMAL64):
		return &TypeSpecifier{Case: TypeSpecifierDecimal64, Token: p.shift(false)}
	case rune(DECIMAL128):
		return &TypeSpecifier{Case: TypeSpecifierDecimal128, Token: p.shift(false)}
	case rune(TYPEOF):
		switch ch := p.peek(2, true).Ch; {
		case p.isTypeSpecifier(ch, true):
			return &TypeSpecifier{Case: TypeSpecifierTypeofType, Token: p.shift(false), Token2: p.must('('), TypeName: p.typeName(), Token3: p.must(')')}
		case p.isExpression(ch):
			return &TypeSpecifier{Case: TypeSpecifierTypeofExpr, Token: p.shift(false), Token2: p.must('('), ExpressionList: p.expression(false), Token3: p.must(')')}
		default:
			t := p.shift(false)
			p.cpp.eh("%v: unexpected %v, expected type specifier", t.Position(), runeName(t.Ch))
			return nil
		}
	default:
		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected type specifier", t.Position(), runeName(t.Ch))
		return nil
	}
}

func (p *parser) isTypeSpecifier(ch rune, typenameOk bool) bool {
	switch ch {
	case
		rune(BOOL),
		rune(CHAR),
		rune(COMPLEX),
		rune(DECIMAL128),
		rune(DECIMAL32),
		rune(DECIMAL64),
		rune(DOUBLE),
		rune(ENUM),
		rune(FLOAT),
		rune(FLOAT128),
		rune(FLOAT128X),
		rune(FLOAT16),
		rune(FLOAT32),
		rune(FLOAT32X),
		rune(FLOAT64),
		rune(FLOAT64X),
		rune(IMAGINARY),
		rune(INT),
		rune(INT128),
		rune(LONG),
		rune(SHORT),
		rune(SIGNED),
		rune(STRUCT),
		rune(TYPEOF),
		rune(UINT128),
		rune(UNION),
		rune(UNSIGNED),
		rune(VOID):

		return true
	case rune(TYPENAME):
		return typenameOk
	}
	return false
}

// [2], 6.7.2.4 Atomic type specifiers
//
//  atomic-type-specifier:
// 	_Atomic ( type-name )
func (p *parser) atomicTypeSpecifier() (r *AtomicTypeSpecifier) {
	return &AtomicTypeSpecifier{Token: p.must(rune(ATOMIC)), Token2: p.must('('), TypeName: p.typeName(), Token3: p.must(')')}
}

// [0], 6.7.2.2 Enumeration specifiers
//
//  enum-specifier:
// 	enum identifier_opt { enumerator-list }
// 	enum identifier_opt { enumerator-list , }
// 	enum identifier
func (p *parser) enumSpecifier() (r *EnumSpecifier) {
	switch p.peek(1, false).Ch {
	case eof:
		p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
		return nil
	case rune(IDENTIFIER):
		switch p.peek(2, true).Ch {
		case '{':
			r = &EnumSpecifier{Case: EnumSpecifierDef, Token: p.shift(false), Token2: p.shift(false), Token3: p.shift(false), EnumeratorList: p.enumeratorList(), lexicalScope: (*lexicalScope)(p.scope)}
			r.visible = visible(r.Token.seq + 1) // [0]6.2.1,7
			p.scope.declare(p.cpp.eh, r.Token2.SrcStr(), r)
		default:
			return &EnumSpecifier{Case: EnumSpecifierTag, Token: p.shift(false), Token2: p.shift(false), lexicalScope: (*lexicalScope)(p.scope)}
		}
	case '{':
		r = &EnumSpecifier{Case: EnumSpecifierDef, Token: p.shift(false), Token3: p.shift(false), EnumeratorList: p.enumeratorList(), lexicalScope: (*lexicalScope)(p.scope)}
	default:
		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected enum specifier", t.Position(), runeName(t.Ch))
		return nil
	}
	switch p.rune(false) {
	case eof:
		p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
		return nil
	case ',':
		r.Token4 = p.shift(false)
		r.Token5 = p.must('}')
		return r
	case '}':
		r.Token5 = p.shift(false)
		return r
	default:
		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected enum specifier", t.Position(), runeName(t.Ch))
		return nil
	}
}

//  enumerator-list:
// 	enumerator
// 	enumerator-list , enumerator
func (p *parser) enumeratorList() (r *EnumeratorList) {
	r = &EnumeratorList{Enumerator: p.enumerator()}
	prev := r
	for {
		switch p.rune(false) {
		case eof:
			p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
			return nil
		case '}':
			return r
		case ',':
			switch p.peek(1, true).Ch {
			case rune(IDENTIFIER):
				e := &EnumeratorList{Token: p.shift(false), Enumerator: p.enumerator()}
				prev.EnumeratorList = e
				prev = e
			default:
				return r
			}
		default:
			t := p.shift(false)
			p.cpp.eh("%v: unexpected %v, expected enumerator", t.Position(), runeName(t.Ch))
		}
	}
}

//  enumerator:
// 	enumeration-constant
// 	enumeration-constant = constant-expression
func (p *parser) enumerator() (r *Enumerator) {
	switch p.peek(1, false).Ch {
	case '}', ',':
		r = &Enumerator{Case: EnumeratorIdent, Token: p.must(rune(IDENTIFIER))}
	case '=':
		r = &Enumerator{Case: EnumeratorExpr, Token: p.must(rune(IDENTIFIER)), Token2: p.shift(false), Expression: p.constantExpression()}
	default:
		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected enumerator", t.Position(), runeName(t.Ch))
		return nil
	}
	r.visible = visible(r.Token.seq + 1)
	p.scope.declare(p.cpp.eh, r.Token.SrcStr(), r)
	return r
}

// [0], 6.7.2.1 Structure and union specifiers
//
//  struct-or-union-specifier:
// 	struct-or-union identifier_opt { struct-declaration-list }
// 	struct-or-union identifier
func (p *parser) structOrUnionSpecifier() (r *StructOrUnionSpecifier) {
	sou := p.structOrUnion()
	attrs := p.attributeSpecifierListOpt()
	switch p.rune(false) {
	case eof:
		p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
		return nil
	case '{':
		return &StructOrUnionSpecifier{Case: StructOrUnionSpecifierDef, StructOrUnion: sou, AttributeSpecifiers: attrs, Token2: p.shift(false), StructDeclarationList: p.structDeclarationList(), Token3: p.must('}'), AttributeSpecifiers2: p.attributeSpecifierListOpt(), lexicalScope: (*lexicalScope)(p.scope)}
	case rune(IDENTIFIER):
		r = &StructOrUnionSpecifier{StructOrUnion: sou, AttributeSpecifiers: attrs, Token: p.shift(false), lexicalScope: (*lexicalScope)(p.scope)}
		r.visible = visible(r.Token.seq + 1) // [0]6.2.1,7
		switch p.rune(false) {
		case eof:
			p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
			return nil
		case '{':
			p.scope.declare(p.cpp.eh, r.Token.SrcStr(), r)
			r.Case = StructOrUnionSpecifierDef
			r.Token2 = p.shift(false)
			r.StructDeclarationList = p.structDeclarationList()
			r.Token3 = p.must('}')
			r.AttributeSpecifiers = p.attributeSpecifierListOpt()
			return r
		default:
			r.Case = StructOrUnionSpecifierTag
			return r
		}
	default:
		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected struct or union specifier", t.Position(), runeName(t.Ch))
		return nil
	}
}

//  struct-declaration-list:
// 	struct-declaration
// 	struct-declaration-list struct-declaration
func (p *parser) structDeclarationList() (r *StructDeclarationList) {
	var prev *StructDeclarationList
	for {
		switch p.rune(false) {
		case eof:
			p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
			return nil
		case '}':
			return r
		default:
			sdl := &StructDeclarationList{StructDeclaration: p.structDeclaration()}
			switch {
			case r == nil:
				r = sdl
			default:
				prev.StructDeclarationList = sdl
			}
			prev = sdl
		}
	}
}

//  struct-declaration:
// 	specifier-qualifier-list struct-declarator-list_opt ;
//	static-assert-declaration ;
func (p *parser) structDeclaration() (r *StructDeclaration) {
	if p.rune(false) == rune(STATICASSERT) {
		r = &StructDeclaration{Case: StructDeclarationAssert, StaticAssertDeclaration: p.staticAssertDeclaration()}
		switch p.rune(false) {
		case ';':
			r.Token = p.shift(false)
		default:
			t := p.toks[0]
			p.cpp.eh("%v: unexpected %v, expected ';'", t.Position(), runeName(t.Ch))
		}
		return r
	}

	r = &StructDeclaration{Case: StructDeclarationDecl, SpecifierQualifierList: p.specifierQualifierList(), StructDeclaratorList: p.structDeclaratorListOpt(), AttributeSpecifiers: p.attributeSpecifierListOpt()}
	switch p.rune(false) {
	case ';':
		r.Token = p.shift(false)
		return r
	case '}':
		return r
	default:
		t := p.toks[0]
		p.cpp.eh("%v: unexpected %v, expected ';'", t.Position(), runeName(t.Ch))
		return r
	}
}

//  struct-declarator-list:
// 	struct-declarator
// 	struct-declarator-list , struct-declarator
func (p *parser) structDeclaratorListOpt() (r *StructDeclaratorList) {
	switch p.rune(false) {
	case
		'(',
		'*',
		':',
		rune(IDENTIFIER):

		// ok
	case ';':
		return nil
	default:
		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected struct declarator list", t.Position(), runeName(t.Ch))
		return nil
	}

	r = &StructDeclaratorList{StructDeclarator: p.structDeclarator()}
	prev := r
	for p.rune(false) == ',' {
		sdl := &StructDeclaratorList{Token: p.shift(false), StructDeclarator: p.structDeclarator()}
		prev.StructDeclaratorList = sdl
		prev = sdl
	}
	return r
}

//  struct-declarator:
// 	declarator
// 	declarator_opt : constant-expression
func (p *parser) structDeclarator() (r *StructDeclarator) {
	switch p.rune(false) {
	case eof:
		p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
		return nil
	case ':':
		return &StructDeclarator{Case: StructDeclaratorBitField, Token: p.shift(false), Expression: p.constantExpression()}
	default:
		r = &StructDeclarator{Case: StructDeclaratorDecl, Declarator: p.declarator(nil, nil, false)}
		if p.rune(false) == ':' {
			r.Case = StructDeclaratorBitField
			r.Token = p.shift(false)
			r.Expression = p.constantExpression()
		}
		return r
	}
}

// [0], 6.6 Constant expressions
//
//  constant-expression:
// 	conditional-expression
func (p *parser) constantExpression() (r *ConstantExpression) {
	r = &ConstantExpression{}
	r.Expression, _ = p.conditionalExpression(true)
	return r
}

// struct-or-union:
//	struct
//	union
func (p *parser) structOrUnion() *StructOrUnion {
	switch p.rune(false) {
	case eof:
		p.cpp.eh("%v: unexpected EOF", p.toks[0].Position())
		return nil
	case rune(STRUCT):
		return &StructOrUnion{Case: StructOrUnionStruct, Token: p.shift(false)}
	case rune(UNION):
		return &StructOrUnion{Case: StructOrUnionUnion, Token: p.shift(false)}
	default:
		t := p.shift(false)
		p.cpp.eh("%v: unexpected %v, expected 'struct' or 'union'", t.Position(), runeName(t.Ch))
		return nil
	}
}

// Scope binds names to declaring nodes.
//
// The dynamic type of a Node in the Nodes map is one of
//
//  Node type                   Note
//  -----------------           ----
//  *Declarator
//  *EnumSpecifier              binds the tag
//  *Enumerator
//  *LabelDeclaration
//  *LabeledStatement           case LabeledStatementLabel
//  *Parameter
//  *StructOrUnionSpecifier     binds the tag
type Scope struct {
	Children []*Scope
	Nodes    map[string][]Node
	Parent   *Scope
}

func newScope(parent *Scope) (r *Scope) {
	r = &Scope{Parent: parent}
	if parent != nil {
		parent.Children = append(parent.Children, r)
	}
	return r
}

func (s *Scope) declare(eh interface{}, nm string, n Node) {
	// trc("%v: %q %T, visible %v (scope %p) '%s' (%v: %v: %v:)", n.Position(), nm, n, n.(interface{ Visible() int }).Visible(), s, NodeSource(n), origin(4), origin(3), origin(2))
	if s.Nodes != nil {
		s.Nodes[nm] = append(s.Nodes[nm], n)
		return
	}

	s.Nodes = map[string][]Node{nm: {n}}
}

func (s *Scope) ident(t Token) Node {
	a := s.idents(t)
	switch len(a) {
	case 1:
		return a[0]
	case 0:
		return nil
	}

	if p, ok := a[0].(*Parameter); ok {
		return p.Declarator
	}

	d, ok := a[0].(*Declarator)
	if !ok {
		return a[0]
	}

	if d.Type().Kind() == Function {
		f := d.Type().(*FunctionType)
		for _, v := range a {
			x, ok := v.(*Declarator)
			if !ok {
				continue
			}

			g, ok := x.Type().(*FunctionType)
			if !ok {
				continue
			}

			if lessFunctionType(f, g) {
				return v
			}
		}

		return a[0]
	}

	for _, v := range a {
		if x, ok := v.(*Declarator); ok && !x.Type().IsIncomplete() {
			return x
		}
	}

	return a[0]
}

func (s *Scope) idents(t Token) (r []Node) {
	nm := t.Src()
	for ; s != nil; s = s.Parent {
		for _, v := range s.Nodes[string(nm)] {
			switch x := v.(type) {
			case *Declarator:
				if t.seq >= int32(x.visible) {
					x.resolved = s
					r = append(r, x)
					switch {
					case x.isExtern:
						for s := s.Parent; s != nil; s = s.Parent {
							for _, v := range s.Nodes[string(nm)] {
								if x, ok := v.(*Declarator); ok && x.isExtern {
									x.resolved = s
									r = append(r, x)
								}
							}
						}
					case x.Type().Kind() == Function && !x.isFuncDef:
						for s := s.Parent; s != nil; s = s.Parent {
							for _, v := range s.Nodes[string(nm)] {
								if x, ok := v.(*Declarator); ok && x.Type().Kind() == Function {
									x.resolved = s
									r = append(r, x)
								}
							}
						}
					}
				}
			case *Enumerator:
				if t.seq >= int32(x.visible) {
					x.resolved = s
					r = append(r, x)
				}
			case *Parameter:
				if t.seq >= int32(x.visible) {
					x.resolved = s
					r = append(r, x)
				}
			}
		}
		if len(r) != 0 {
			return r
		}
	}
	return nil
}

func (s *Scope) builtin(t Token) *Declarator {
	nm := "__builtin_" + t.SrcStr()
	for ; s != nil; s = s.Parent {
		for _, v := range s.Nodes[nm] {
			switch x := v.(type) {
			case *Declarator:
				if t.seq >= int32(x.visible) {
					return x
				}
			}
		}
	}
	return nil
}

func (s *Scope) enum(t Token) *EnumSpecifier {
	for ; s != nil; s = s.Parent {
		for _, v := range s.Nodes[string(t.Src())] {
			switch x := v.(type) {
			case *EnumSpecifier:
				return x
			}
		}
	}
	return nil
}

func (s *Scope) structOrUnion(t Token) *StructOrUnionSpecifier {
	for ; s != nil; s = s.Parent {
		for _, v := range s.Nodes[string(t.Src())] {
			switch x := v.(type) {
			case *StructOrUnionSpecifier:
				return x
			}
		}
	}
	return nil
}

type visible int32

// Visible reports the token sequence number where the visibility of a name starts.
func (v visible) Visible() int { return int(v) }

type lexicalScope Scope

// LexicalScope provides the scope a node appears in.
func (n *lexicalScope) LexicalScope() *Scope { return (*Scope)(n) }