/lib/ext/melbourne/grammar.y

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/**********************************************************************

  parse.y -

  $Author: matz $
  $Date: 2004/11/29 06:13:51 $
  created at: Fri May 28 18:02:42 JST 1993

  Copyright (C) 1993-2003 Yukihiro Matsumoto

**********************************************************************/

%{

#define YYDEBUG 1
#define YYERROR_VERBOSE 1

#include <stdio.h>
#include <errno.h>
#include <ctype.h>
#include <string.h>
#include <stdbool.h>
#include <assert.h>

#include "ruby.h"

#include "internal.hpp"
#include "visitor.hpp"
#include "local_state.hpp"

namespace melbourne {

#ifndef isnumber
#define isnumber isdigit
#endif

/* Defined at least in mach/boolean.h on OS X. */
#ifdef  TRUE
  #undef  TRUE
#endif

#ifdef  FALSE
  #undef FALSE
#endif

#define TRUE  true
#define FALSE false

/*
#define ISALPHA isalpha
#define ISSPACE isspace
#define ISALNUM(x) (isalpha(x) || isnumber(x))
#define ISDIGIT isdigit
#define ISXDIGIT isxdigit
#define ISUPPER isupper
*/

#define ismbchar(c) (0)
#define mbclen(c) (1)

#define string_new(ptr, len) blk2bstr(ptr, len)
#define string_new2(ptr) cstr2bstr(ptr)

long mel_sourceline;
static char *mel_sourcefile;

#define ruby_sourceline mel_sourceline
#define ruby_sourcefile mel_sourcefile

static int
mel_yyerror(const char *, rb_parse_state*);
#define yyparse mel_yyparse
#define yylex mel_yylex
#define yyerror(str) mel_yyerror(str, (rb_parse_state*)parse_state)
#define yylval mel_yylval
#define yychar mel_yychar
#define yydebug mel_yydebug

#define YYPARSE_PARAM parse_state
#define YYLEX_PARAM parse_state

#define ID_SCOPE_SHIFT 3
#define ID_SCOPE_MASK 0x07
#define ID_LOCAL    0x01
#define ID_INSTANCE 0x02
#define ID_GLOBAL   0x03
#define ID_ATTRSET  0x04
#define ID_CONST    0x05
#define ID_CLASS    0x06
#define ID_JUNK     0x07
#define ID_INTERNAL ID_JUNK

#define is_notop_id(id) ((id)>tLAST_TOKEN)
#define is_local_id(id) (is_notop_id(id)&&((id)&ID_SCOPE_MASK)==ID_LOCAL)
#define is_global_id(id) (is_notop_id(id)&&((id)&ID_SCOPE_MASK)==ID_GLOBAL)
#define is_instance_id(id) (is_notop_id(id)&&((id)&ID_SCOPE_MASK)==ID_INSTANCE)
#define is_attrset_id(id) (is_notop_id(id)&&((id)&ID_SCOPE_MASK)==ID_ATTRSET)
#define is_const_id(id) (is_notop_id(id)&&((id)&ID_SCOPE_MASK)==ID_CONST)
#define is_class_id(id) (is_notop_id(id)&&((id)&ID_SCOPE_MASK)==ID_CLASS)
#define is_junk_id(id) (is_notop_id(id)&&((id)&ID_SCOPE_MASK)==ID_JUNK)

#define is_asgn_or_id(id) ((is_notop_id(id)) && \
        (((id)&ID_SCOPE_MASK) == ID_GLOBAL || \
         ((id)&ID_SCOPE_MASK) == ID_INSTANCE || \
         ((id)&ID_SCOPE_MASK) == ID_CLASS))


/* FIXME these went into the ruby_state instead of parse_state
   because a ton of other crap depends on it
char *ruby_sourcefile;          current source file
int   ruby_sourceline;          current line no.
*/
static int yylex(void*, void *);


#define BITSTACK_PUSH(stack, n) (stack = (stack<<1)|((n)&1))
#define BITSTACK_POP(stack)     (stack >>= 1)
#define BITSTACK_LEXPOP(stack)  (stack = (stack >> 1) | (stack & 1))
#define BITSTACK_SET_P(stack)   (stack&1)

#define COND_PUSH(n)    BITSTACK_PUSH(vps->cond_stack, n)
#define COND_POP()      BITSTACK_POP(vps->cond_stack)
#define COND_LEXPOP()   BITSTACK_LEXPOP(vps->cond_stack)
#define COND_P()        BITSTACK_SET_P(vps->cond_stack)

#define CMDARG_PUSH(n)  BITSTACK_PUSH(vps->cmdarg_stack, n)
#define CMDARG_POP()    BITSTACK_POP(vps->cmdarg_stack)
#define CMDARG_LEXPOP() BITSTACK_LEXPOP(vps->cmdarg_stack)
#define CMDARG_P()      BITSTACK_SET_P(vps->cmdarg_stack)

/*
static int class_nest = 0;
static int in_single = 0;
static int in_def = 0;
static int compile_for_eval = 0;
static ID cur_mid = 0;
*/

static NODE *cond(NODE*,rb_parse_state*);
static NODE *logop(enum node_type,NODE*,NODE*,rb_parse_state*);
static int cond_negative(NODE**);

static NODE *newline_node(rb_parse_state*,NODE*);
static void fixpos(NODE*,NODE*);

static int value_expr0(NODE*,rb_parse_state*);
static void void_expr0(NODE*,rb_parse_state*);
static void void_stmts(NODE*,rb_parse_state*);
static NODE *remove_begin(NODE*,rb_parse_state*);
#define  value_expr(node)  value_expr0((node) = \
                              remove_begin(node, (rb_parse_state*)parse_state), \
                              (rb_parse_state*)parse_state)
#define void_expr(node) void_expr0((node) = \
                              remove_begin(node, (rb_parse_state*)parse_state), \
                              (rb_parse_state*)parse_state)

static NODE *block_append(rb_parse_state*,NODE*,NODE*);
static NODE *list_append(rb_parse_state*,NODE*,NODE*);
static NODE *list_concat(NODE*,NODE*);
static NODE *arg_concat(rb_parse_state*,NODE*,NODE*);
static NODE *arg_prepend(rb_parse_state*,NODE*,NODE*);
static NODE *literal_concat(rb_parse_state*,NODE*,NODE*);
static NODE *new_evstr(rb_parse_state*,NODE*);
static NODE *evstr2dstr(rb_parse_state*,NODE*);
static NODE *call_op(NODE*,QUID,int,NODE*,rb_parse_state*);

/* static NODE *negate_lit(NODE*); */
static NODE *ret_args(rb_parse_state*,NODE*);
static NODE *arg_blk_pass(NODE*,NODE*);
static NODE *new_call(rb_parse_state*,NODE*,QUID,NODE*);
static NODE *new_fcall(rb_parse_state*,QUID,NODE*);
static NODE *new_super(rb_parse_state*,NODE*);
static NODE *new_yield(rb_parse_state*,NODE*);

static NODE *mel_gettable(rb_parse_state*,QUID);
#define gettable(i) mel_gettable((rb_parse_state*)parse_state, i)
static NODE *assignable(QUID,NODE*,rb_parse_state*);
static NODE *aryset(NODE*,NODE*,rb_parse_state*);
static NODE *attrset(NODE*,QUID,rb_parse_state*);
static void rb_backref_error(NODE*,rb_parse_state*);
static NODE *node_assign(NODE*,NODE*,rb_parse_state*);

static NODE *match_gen(NODE*,NODE*,rb_parse_state*);
static void mel_local_push(rb_parse_state*, int cnt);
#define local_push(cnt) mel_local_push(vps, cnt)
static void mel_local_pop(rb_parse_state*);
#define local_pop() mel_local_pop(vps)
static intptr_t  mel_local_cnt(rb_parse_state*,QUID);
#define local_cnt(i) mel_local_cnt(vps, i)
static int  mel_local_id(rb_parse_state*,QUID);
#define local_id(i) mel_local_id(vps, i)
static QUID  *mel_local_tbl(rb_parse_state *st);
static QUID   convert_op(QUID id);



static void tokadd(char c, rb_parse_state *parse_state);
static int tokadd_string(int, int, int, QUID*, rb_parse_state*);

#define SHOW_PARSER_WARNS 0

static int rb_compile_error(rb_parse_state *st, const char *fmt, ...) {
  va_list ar;
  char msg[256];
  int count;

  va_start(ar, fmt);
  count = vsnprintf(msg, 256, fmt, ar);
  va_end(ar);

  mel_yyerror(msg, st);

  return count;
}

static int _debug_print(const char *fmt, ...) {
#if SHOW_PARSER_WARNS
  va_list ar;
  int i;

  va_start(ar, fmt);
  i = vprintf(fmt, ar);
  va_end(ar);
  return i;
#else
  return 0;
#endif
}

#define rb_warn _debug_print
#define rb_warning _debug_print

static QUID rb_intern(const char *name);
static QUID rb_id_attrset(QUID);

rb_parse_state *alloc_parse_state();
static unsigned long scan_oct(const char *start, int len, int *retlen);
static unsigned long scan_hex(const char *start, int len, int *retlen);

static void reset_block(rb_parse_state *parse_state);
static NODE *extract_block_vars(rb_parse_state *parse_state, NODE* node, var_table vars);

#define RE_OPTION_ONCE 0x80
#define RE_OPTION_IGNORECASE (1L)
#define RE_OPTION_EXTENDED   (RE_OPTION_IGNORECASE<<1)
#define RE_OPTION_MULTILINE  (RE_OPTION_EXTENDED<<1)
#define RE_OPTION_SINGLELINE (RE_OPTION_MULTILINE<<1)
#define RE_OPTION_LONGEST    (RE_OPTION_SINGLELINE<<1)
#define RE_MAY_IGNORECASE    (RE_OPTION_LONGEST<<1)
#define RE_OPTIMIZE_ANCHOR   (RE_MAY_IGNORECASE<<1)
#define RE_OPTIMIZE_EXACTN   (RE_OPTIMIZE_ANCHOR<<1)
#define RE_OPTIMIZE_NO_BM    (RE_OPTIMIZE_EXACTN<<1)
#define RE_OPTIMIZE_BMATCH   (RE_OPTIMIZE_NO_BM<<1)

#define NODE_STRTERM NODE_ZARRAY        /* nothing to gc */
#define NODE_HEREDOC NODE_ARRAY         /* 1, 3 to gc */
#define SIGN_EXTEND(x,n) (((1<<((n)-1))^((x)&~(~0<<(n))))-(1<<((n)-1)))
#define nd_func u1.id
#if SIZEOF_SHORT != 2
#define nd_term(node) SIGN_EXTEND((node)->u2.id, (CHAR_BIT*2))
#else
#define nd_term(node) ((signed short)(node)->u2.id)
#endif
#define nd_paren(node) (char)((node)->u2.id >> (CHAR_BIT*2))
#define nd_nest u3.id

/* Older versions of Yacc set YYMAXDEPTH to a very low value by default (150,
   for instance).  This is too low for Ruby to parse some files, such as
   date/format.rb, therefore bump the value up to at least Bison's default. */
#ifdef OLD_YACC
#ifndef YYMAXDEPTH
#define YYMAXDEPTH 10000
#endif
#endif

#define vps ((rb_parse_state*)parse_state)

%}

%pure-parser

%union {
    NODE *node;
    QUID id;
    int num;
    var_table vars;
}

%token  kCLASS
        kMODULE
        kDEF
        kUNDEF
        kBEGIN
        kRESCUE
        kENSURE
        kEND
        kIF
        kUNLESS
        kTHEN
        kELSIF
        kELSE
        kCASE
        kWHEN
        kWHILE
        kUNTIL
        kFOR
        kBREAK
        kNEXT
        kREDO
        kRETRY
        kIN
        kDO
        kDO_COND
        kDO_BLOCK
        kRETURN
        kYIELD
        kSUPER
        kSELF
        kNIL
        kTRUE
        kFALSE
        kAND
        kOR
        kNOT
        kIF_MOD
        kUNLESS_MOD
        kWHILE_MOD
        kUNTIL_MOD
        kRESCUE_MOD
        kALIAS
        kDEFINED
        klBEGIN
        klEND
        k__LINE__
        k__FILE__

%token <id>   tIDENTIFIER tFID tGVAR tIVAR tCONSTANT tCVAR tXSTRING_BEG
%token <node> tINTEGER tFLOAT tSTRING_CONTENT
%token <node> tNTH_REF tBACK_REF
%token <num>  tREGEXP_END
%type <node> singleton strings string string1 xstring regexp
%type <node> string_contents xstring_contents string_content
%type <node> words qwords word_list qword_list word
%type <node> literal numeric dsym cpath
%type <node> bodystmt compstmt stmts stmt expr arg primary command command_call method_call
%type <node> expr_value arg_value primary_value
%type <node> if_tail opt_else case_body cases opt_rescue exc_list exc_var opt_ensure
%type <node> args when_args call_args call_args2 open_args paren_args opt_paren_args
%type <node> command_args aref_args opt_block_arg block_arg var_ref var_lhs
%type <node> mrhs superclass block_call block_command
%type <node> f_arglist f_args f_optarg f_opt f_block_arg opt_f_block_arg
%type <node> assoc_list assocs assoc undef_list backref string_dvar
%type <node> block_var opt_block_var brace_block cmd_brace_block do_block lhs none fitem
%type <node> mlhs mlhs_head mlhs_basic mlhs_entry mlhs_item mlhs_node
%type <id>   fsym variable sym symbol operation operation2 operation3
%type <id>   cname fname op f_rest_arg
%type <num>  f_norm_arg f_arg
%token tUPLUS           /* unary+ */
%token tUMINUS          /* unary- */
%token tUBS             /* unary\ */
%token tPOW             /* ** */
%token tCMP             /* <=> */
%token tEQ              /* == */
%token tEQQ             /* === */
%token tNEQ             /* != */
%token tGEQ             /* >= */
%token tLEQ             /* <= */
%token tANDOP tOROP     /* && and || */
%token tMATCH tNMATCH   /* =~ and !~ */
%token tDOT2 tDOT3      /* .. and ... */
%token tAREF tASET      /* [] and []= */
%token tLSHFT tRSHFT    /* << and >> */
%token tCOLON2          /* :: */
%token tCOLON3          /* :: at EXPR_BEG */
%token <id> tOP_ASGN    /* +=, -=  etc. */
%token tASSOC           /* => */
%token tLPAREN          /* ( */
%token tLPAREN_ARG      /* ( */
%token tRPAREN          /* ) */
%token tLBRACK          /* [ */
%token tLBRACE          /* { */
%token tLBRACE_ARG      /* { */
%token tSTAR            /* * */
%token tAMPER           /* & */
%token tSYMBEG tSTRING_BEG tREGEXP_BEG tWORDS_BEG tQWORDS_BEG
%token tSTRING_DBEG tSTRING_DVAR tSTRING_END

/*
 *      precedence table
 */

%nonassoc tLOWEST
%nonassoc tLBRACE_ARG

%nonassoc  kIF_MOD kUNLESS_MOD kWHILE_MOD kUNTIL_MOD
%left  kOR kAND
%right kNOT
%nonassoc kDEFINED
%right '=' tOP_ASGN
%left kRESCUE_MOD
%right '?' ':'
%nonassoc tDOT2 tDOT3
%left  tOROP
%left  tANDOP
%nonassoc  tCMP tEQ tEQQ tNEQ tMATCH tNMATCH
%left  '>' tGEQ '<' tLEQ
%left  '|' '^'
%left  '&'
%left  tLSHFT tRSHFT
%left  '+' '-'
%left  '*' '/' '%'
%right tUMINUS_NUM tUMINUS
%right tPOW
%right '!' '~' tUPLUS

%token tLAST_TOKEN

%%
program         :  {
                        vps->lex_state = EXPR_BEG;
                        vps->variables = new LocalState(0);
                        class_nest = 0;
                    }
                  compstmt
                    {
                        if ($2 && !compile_for_eval) {
                            /* last expression should not be void */
                            if (nd_type($2) != NODE_BLOCK) void_expr($2);
                            else {
                                NODE *node = $2;
                                while (node->nd_next) {
                                    node = node->nd_next;
                                }
                                void_expr(node->nd_head);
                            }
                        }
                        vps->top = block_append(vps, vps->top, $2);
                        class_nest = 0;
                    }
                ;

bodystmt        : compstmt
                  opt_rescue
                  opt_else
                  opt_ensure
                    {
                        $$ = $1;
                        if ($2) {
                            $$ = NEW_RESCUE($1, $2, $3);
                        }
                        else if ($3) {
                            rb_warn("else without rescue is useless");
                            $$ = block_append(vps, $$, $3);
                        }
                        if ($4) {
                            $$ = NEW_ENSURE($$, $4);
                        }
                        fixpos($$, $1);
                    }
                ;

compstmt        : stmts opt_terms
                    {
                        void_stmts($1, vps);
                        $$ = $1;
                    }
                ;

stmts           : none
                | stmt
                    {
                        $$ = newline_node(vps, $1);
                    }
                | stmts terms stmt
                    {
                        $$ = block_append(vps, $1, newline_node(vps, $3));
                    }
                | error stmt
                    {
                        $$ = remove_begin($2, vps);
                    }
                ;

stmt            : kALIAS fitem {vps->lex_state = EXPR_FNAME;} fitem
                    {
                        $$ = NEW_ALIAS($2, $4);
                    }
                | kALIAS tGVAR tGVAR
                    {
                        $$ = NEW_VALIAS($2, $3);
                    }
                | kALIAS tGVAR tBACK_REF
                    {
                        char buf[3];

                        snprintf(buf, sizeof(buf), "$%c", (char)$3->nd_nth);
                        $$ = NEW_VALIAS($2, rb_intern(buf));
                    }
                | kALIAS tGVAR tNTH_REF
                    {
                        yyerror("can't make alias for the number variables");
                        $$ = 0;
                    }
                | kUNDEF undef_list
                    {
                        $$ = $2;
                    }
                | stmt kIF_MOD expr_value
                    {
                        $$ = NEW_IF(cond($3, vps), remove_begin($1, vps), 0);
                        fixpos($$, $3);
                        if (cond_negative(&$$->nd_cond)) {
                            $$->nd_else = $$->nd_body;
                            $$->nd_body = 0;
                        }
                    }
                | stmt kUNLESS_MOD expr_value
                    {
                        $$ = NEW_UNLESS(cond($3, vps), remove_begin($1, vps), 0);
                        fixpos($$, $3);
                        if (cond_negative(&$$->nd_cond)) {
                            $$->nd_body = $$->nd_else;
                            $$->nd_else = 0;
                        }
                    }
                | stmt kWHILE_MOD expr_value
                    {
                        if ($1 && nd_type($1) == NODE_BEGIN) {
                            $$ = NEW_WHILE(cond($3, vps), $1->nd_body, 0);
                        }
                        else {
                            $$ = NEW_WHILE(cond($3, vps), $1, 1);
                        }
                        if (cond_negative(&$$->nd_cond)) {
                            nd_set_type($$, NODE_UNTIL);
                        }
                    }
                | stmt kUNTIL_MOD expr_value
                    {
                        if ($1 && nd_type($1) == NODE_BEGIN) {
                            $$ = NEW_UNTIL(cond($3, vps), $1->nd_body, 0);
                        }
                        else {
                            $$ = NEW_UNTIL(cond($3, vps), $1, 1);
                        }
                        if (cond_negative(&$$->nd_cond)) {
                            nd_set_type($$, NODE_WHILE);
                        }
                    }
                | stmt kRESCUE_MOD stmt
                    {
                        NODE *resq = NEW_RESBODY(0, remove_begin($3, vps), 0);
                        $$ = NEW_RESCUE(remove_begin($1, vps), resq, 0);
                    }
                | klBEGIN
                    {
                        if (in_def || in_single) {
                            yyerror("BEGIN in method");
                        }
                        local_push(0);
                    }
                  '{' compstmt '}'
                    {
                        /*
                        ruby_eval_tree_begin = block_append(ruby_eval_tree_begin,
                                                            NEW_PREEXE($4));
                        */
                        local_pop();
                        $$ = 0;
                    }
                | klEND '{' compstmt '}'
                    {
                        if (in_def || in_single) {
                            rb_warn("END in method; use at_exit");
                        }

                        $$ = NEW_ITER(0, NEW_POSTEXE(), $3);
                    }
                | lhs '=' command_call
                    {
                        $$ = node_assign($1, $3, vps);
                    }
                | mlhs '=' command_call
                    {
                        value_expr($3);
                        $1->nd_value = ($1->nd_head) ? NEW_TO_ARY($3) : NEW_ARRAY($3);
                        $$ = $1;
                    }
                | var_lhs tOP_ASGN command_call
                    {
                        value_expr($3);
                        if ($1) {
                            QUID vid = $1->nd_vid;
                            if ($2 == tOROP) {
                                $1->nd_value = $3;
                                $$ = NEW_OP_ASGN_OR(gettable(vid), $1);
                                if (is_asgn_or_id(vid)) {
                                    $$->nd_aid = vid;
                                }
                            }
                            else if ($2 == tANDOP) {
                                $1->nd_value = $3;
                                $$ = NEW_OP_ASGN_AND(gettable(vid), $1);
                            }
                            else {
                                $$ = $1;
                                $$->nd_value = call_op(gettable(vid),$2,1,$3, vps);
                            }
                        }
                        else {
                            $$ = 0;
                        }
                    }
                | primary_value '[' aref_args ']' tOP_ASGN command_call
                    {
                        NODE *args;

                        value_expr($6);
                        if (!$3) $3 = NEW_ZARRAY();
                        args = arg_concat(vps, $6, $3);
                        if ($5 == tOROP) {
                            $5 = 0;
                        }
                        else if ($5 == tANDOP) {
                            $5 = 1;
                        }
                        $$ = NEW_OP_ASGN1($1, $5, args);
                        fixpos($$, $1);
                    }
                | primary_value '.' tIDENTIFIER tOP_ASGN command_call
                    {
                        value_expr($5);
                        if ($4 == tOROP) {
                            $4 = 0;
                        }
                        else if ($4 == tANDOP) {
                            $4 = 1;
                        }
                        $$ = NEW_OP_ASGN2($1, $3, $4, $5);
                        fixpos($$, $1);
                    }
                | primary_value '.' tCONSTANT tOP_ASGN command_call
                    {
                        value_expr($5);
                        if ($4 == tOROP) {
                            $4 = 0;
                        }
                        else if ($4 == tANDOP) {
                            $4 = 1;
                        }
                        $$ = NEW_OP_ASGN2($1, $3, $4, $5);
                        fixpos($$, $1);
                    }
                | primary_value tCOLON2 tIDENTIFIER tOP_ASGN command_call
                    {
                        value_expr($5);
                        if ($4 == tOROP) {
                            $4 = 0;
                        }
                        else if ($4 == tANDOP) {
                            $4 = 1;
                        }
                        $$ = NEW_OP_ASGN2($1, $3, $4, $5);
                        fixpos($$, $1);
                    }
                | backref tOP_ASGN command_call
                    {
                        rb_backref_error($1, vps);
                        $$ = 0;
                    }
                | lhs '=' mrhs
                    {
                        $$ = node_assign($1, NEW_SVALUE($3), vps);
                    }
                | mlhs '=' arg_value
                    {
                        $1->nd_value = ($1->nd_head) ? NEW_TO_ARY($3) : NEW_ARRAY($3);
                        $$ = $1;
                    }
                | mlhs '=' mrhs
                    {
                        $1->nd_value = $3;
                        $$ = $1;
                    }
                | expr
                ;

expr            : command_call
                | expr kAND expr
                    {
                        $$ = logop(NODE_AND, $1, $3, vps);
                    }
                | expr kOR expr
                    {
                        $$ = logop(NODE_OR, $1, $3, vps);
                    }
                | kNOT expr
                    {
                        $$ = NEW_NOT(cond($2, vps));
                    }
                | '!' command_call
                    {
                        $$ = NEW_NOT(cond($2, vps));
                    }
                | arg
                ;

expr_value      : expr
                    {
                        value_expr($$);
                        $$ = $1;
                    }
                ;

command_call    : command
                | block_command
                | kRETURN call_args
                    {
                        $$ = NEW_RETURN(ret_args(vps, $2));
                    }
                | kBREAK call_args
                    {
                        $$ = NEW_BREAK(ret_args(vps, $2));
                    }
                | kNEXT call_args
                    {
                        $$ = NEW_NEXT(ret_args(vps, $2));
                    }
                ;

block_command   : block_call
                | block_call '.' operation2 command_args
                    {
                        $$ = new_call(vps, $1, $3, $4);
                    }
                | block_call tCOLON2 operation2 command_args
                    {
                        $$ = new_call(vps, $1, $3, $4);
                    }
                ;

cmd_brace_block : tLBRACE_ARG
                    {
                        $<num>1 = ruby_sourceline;
                        reset_block(vps);
                    }
                  opt_block_var { $<vars>$ = vps->variables->block_vars; }
                  compstmt
                  '}'
                    {
                        $$ = NEW_ITER($3, 0, extract_block_vars(vps, $5, $<vars>4));
                        nd_set_line($$, $<num>1);
                    }
                ;

command         : operation command_args       %prec tLOWEST
                    {
                        $$ = new_fcall(vps, $1, $2);
                        fixpos($$, $2);
                   }
                | operation command_args cmd_brace_block
                    {
                        $$ = new_fcall(vps, $1, $2);
                        if ($3) {
                            if (nd_type($$) == NODE_BLOCK_PASS) {
                                rb_compile_error(vps, "both block arg and actual block given");
                            }
                            $3->nd_iter = $$;
                            $$ = $3;
                        }
                        fixpos($$, $2);
                   }
                | primary_value '.' operation2 command_args     %prec tLOWEST
                    {
                        $$ = new_call(vps, $1, $3, $4);
                        fixpos($$, $1);
                    }
                | primary_value '.' operation2 command_args cmd_brace_block
                    {
                        $$ = new_call(vps, $1, $3, $4);
                        if ($5) {
                            if (nd_type($$) == NODE_BLOCK_PASS) {
                                rb_compile_error(vps, "both block arg and actual block given");
                            }
                            $5->nd_iter = $$;
                            $$ = $5;
                        }
                        fixpos($$, $1);
                   }
                | primary_value tCOLON2 operation2 command_args %prec tLOWEST
                    {
                        $$ = new_call(vps, $1, $3, $4);
                        fixpos($$, $1);
                    }
                | primary_value tCOLON2 operation2 command_args cmd_brace_block
                    {
                        $$ = new_call(vps, $1, $3, $4);
                        if ($5) {
                            if (nd_type($$) == NODE_BLOCK_PASS) {
                                rb_compile_error(vps, "both block arg and actual block given");
                            }
                            $5->nd_iter = $$;
                            $$ = $5;
                        }
                        fixpos($$, $1);
                   }
                | kSUPER command_args
                    {
                        $$ = new_super(vps, $2);
                        fixpos($$, $2);
                    }
                | kYIELD command_args
                    {
                        $$ = new_yield(vps, $2);
                        fixpos($$, $2);
                    }
                ;

mlhs            : mlhs_basic
                | tLPAREN mlhs_entry ')'
                    {
                        $$ = $2;
                    }
                ;

mlhs_entry      : mlhs_basic
                | tLPAREN mlhs_entry ')'
                    {
                        $$ = NEW_MASGN(NEW_LIST($2), 0);
                    }
                ;

mlhs_basic      : mlhs_head
                    {
                        $$ = NEW_MASGN($1, 0);
                    }
                | mlhs_head mlhs_item
                    {
                        $$ = NEW_MASGN(list_append(vps, $1,$2), 0);
                    }
                | mlhs_head tSTAR mlhs_node
                    {
                        $$ = NEW_MASGN($1, $3);
                    }
                | mlhs_head tSTAR
                    {
                        $$ = NEW_MASGN($1, -1);
                    }
                | tSTAR mlhs_node
                    {
                        $$ = NEW_MASGN(0, $2);
                    }
                | tSTAR
                    {
                        $$ = NEW_MASGN(0, -1);
                    }
                ;

mlhs_item       : mlhs_node
                | tLPAREN mlhs_entry ')'
                    {
                        $$ = $2;
                    }
                ;

mlhs_head       : mlhs_item ','
                    {
                        $$ = NEW_LIST($1);
                    }
                | mlhs_head mlhs_item ','
                    {
                        $$ = list_append(vps, $1, $2);
                    }
                ;

mlhs_node       : variable
                    {
                        $$ = assignable($1, 0, vps);
                    }
                | primary_value '[' aref_args ']'
                    {
                        $$ = aryset($1, $3, vps);
                    }
                | primary_value '.' tIDENTIFIER
                    {
                        $$ = attrset($1, $3, vps);
                    }
                | primary_value tCOLON2 tIDENTIFIER
                    {
                        $$ = attrset($1, $3, vps);
                    }
                | primary_value '.' tCONSTANT
                    {
                        $$ = attrset($1, $3, vps);
                    }
                | primary_value tCOLON2 tCONSTANT
                    {
                        if (in_def || in_single)
                            yyerror("dynamic constant assignment");
                        $$ = NEW_CDECL(0, 0, NEW_COLON2($1, $3));
                    }
                | tCOLON3 tCONSTANT
                    {
                        if (in_def || in_single)
                            yyerror("dynamic constant assignment");
                        $$ = NEW_CDECL(0, 0, NEW_COLON3($2));
                    }
                | backref
                    {
                        rb_backref_error($1, vps);
                        $$ = 0;
                    }
                ;

lhs             : variable
                    {
                        $$ = assignable($1, 0, vps);
                    }
                | primary_value '[' aref_args ']'
                    {
                        $$ = aryset($1, $3, vps);
                    }
                | primary_value '.' tIDENTIFIER
                    {
                        $$ = attrset($1, $3, vps);
                    }
                | primary_value tCOLON2 tIDENTIFIER
                    {
                        $$ = attrset($1, $3, vps);
                    }
                | primary_value '.' tCONSTANT
                    {
                        $$ = attrset($1, $3, vps);
                    }
                | primary_value tCOLON2 tCONSTANT
                    {
                        if (in_def || in_single)
                            yyerror("dynamic constant assignment");
                        $$ = NEW_CDECL(0, 0, NEW_COLON2($1, $3));
                    }
                | tCOLON3 tCONSTANT
                    {
                        if (in_def || in_single)
                            yyerror("dynamic constant assignment");
                        $$ = NEW_CDECL(0, 0, NEW_COLON3($2));
                    }
                | backref
                    {
                        rb_backref_error($1, vps);
                        $$ = 0;
                    }
                ;

cname           : tIDENTIFIER
                    {
                        yyerror("class/module name must be CONSTANT");
                    }
                | tCONSTANT
                ;

cpath           : tCOLON3 cname
                    {
                        $$ = NEW_COLON3($2);
                    }
                | cname
                    {
                        $$ = NEW_COLON2(0, $$);
                    }
                | primary_value tCOLON2 cname
                    {
                        $$ = NEW_COLON2($1, $3);
                    }
                ;

fname           : tIDENTIFIER
                | tCONSTANT
                | tFID
                | op
                    {
                        vps->lex_state = EXPR_END;
                        $$ = convert_op($1);
                    }
                | reswords
                    {
                        vps->lex_state = EXPR_END;
                        $$ = $<id>1;
                    }
                ;

fsym            : fname
                | symbol
                ;

fitem           : fsym
                    {
                        $$ = NEW_LIT(ID2SYM($1));
                    }
                | dsym
                ;

undef_list      : fitem
                    {
                        $$ = NEW_UNDEF($1);
                    }
                | undef_list ',' {vps->lex_state = EXPR_FNAME;} fitem
                    {
                        $$ = block_append(vps, $1, NEW_UNDEF($4));
                    }
                ;

op              : '|'           { $$ = '|'; }
                | '^'           { $$ = '^'; }
                | '&'           { $$ = '&'; }
                | tCMP          { $$ = tCMP; }
                | tEQ           { $$ = tEQ; }
                | tEQQ          { $$ = tEQQ; }
                | tMATCH        { $$ = tMATCH; }
                | '>'           { $$ = '>'; }
                | tGEQ          { $$ = tGEQ; }
                | '<'           { $$ = '<'; }
                | tLEQ          { $$ = tLEQ; }
                | tLSHFT        { $$ = tLSHFT; }
                | tRSHFT        { $$ = tRSHFT; }
                | '+'           { $$ = '+'; }
                | '-'           { $$ = '-'; }
                | '*'           { $$ = '*'; }
                | tSTAR         { $$ = '*'; }
                | '/'           { $$ = '/'; }
                | '%'           { $$ = '%'; }
                | tPOW          { $$ = tPOW; }
                | '~'           { $$ = '~'; }
                | tUPLUS        { $$ = tUPLUS; }
                | tUMINUS       { $$ = tUMINUS; }
                | tAREF         { $$ = tAREF; }
                | tASET         { $$ = tASET; }
                | '`'           { $$ = '`'; }
                ;

reswords        : k__LINE__ | k__FILE__  | klBEGIN | klEND
                | kALIAS | kAND | kBEGIN | kBREAK | kCASE | kCLASS | kDEF
                | kDEFINED | kDO | kELSE | kELSIF | kEND | kENSURE | kFALSE
                | kFOR | kIN | kMODULE | kNEXT | kNIL | kNOT
                | kOR | kREDO | kRESCUE | kRETRY | kRETURN | kSELF | kSUPER
                | kTHEN | kTRUE | kUNDEF | kWHEN | kYIELD
                | kIF_MOD | kUNLESS_MOD | kWHILE_MOD | kUNTIL_MOD | kRESCUE_MOD
                ;

arg             : lhs '=' arg
                    {
                        $$ = node_assign($1, $3, vps);
                    }
                | lhs '=' arg kRESCUE_MOD arg
                    {
                        $$ = node_assign($1, NEW_RESCUE($3, NEW_RESBODY(0,$5,0), 0), vps);
                    }
                | var_lhs tOP_ASGN arg
                    {
                        value_expr($3);
                        if ($1) {
                            QUID vid = $1->nd_vid;
                            if ($2 == tOROP) {
                                $1->nd_value = $3;
                                $$ = NEW_OP_ASGN_OR(gettable(vid), $1);
                                if (is_asgn_or_id(vid)) {
                                    $$->nd_aid = vid;
                                }
                            }
                            else if ($2 == tANDOP) {
                                $1->nd_value = $3;
                                $$ = NEW_OP_ASGN_AND(gettable(vid), $1);
                            }
                            else {
                                $$ = $1;
                                $$->nd_value = call_op(gettable(vid),$2,1,$3, vps);
                            }
                        }
                        else {
                            $$ = 0;
                        }
                    }
                | primary_value '[' aref_args ']' tOP_ASGN arg
                    {
                        NODE *args;

                        value_expr($6);
                        if (!$3) $3 = NEW_ZARRAY();
                        args = arg_concat(vps, $6, $3);
                        if ($5 == tOROP) {
                            $5 = 0;
                        }
                        else if ($5 == tANDOP) {
                            $5 = 1;
                        }
                        $$ = NEW_OP_ASGN1($1, $5, args);
                        fixpos($$, $1);
                    }
                | primary_value '.' tIDENTIFIER tOP_ASGN arg
                    {
                        value_expr($5);
                        if ($4 == tOROP) {
                            $4 = 0;
                        }
                        else if ($4 == tANDOP) {
                            $4 = 1;
                        }
                        $$ = NEW_OP_ASGN2($1, $3, $4, $5);
                        fixpos($$, $1);
                    }
                | primary_value '.' tCONSTANT tOP_ASGN arg
                    {
                        value_expr($5);
                        if ($4 == tOROP) {
                            $4 = 0;
                        }
                        else if ($4 == tANDOP) {
                            $4 = 1;
                        }
                        $$ = NEW_OP_ASGN2($1, $3, $4, $5);
                        fixpos($$, $1);
                    }
                | primary_value tCOLON2 tIDENTIFIER tOP_ASGN arg
                    {
                        value_expr($5);
                        if ($4 == tOROP) {
                            $4 = 0;
                        }
                        else if ($4 == tANDOP) {
                            $4 = 1;
                        }
                        $$ = NEW_OP_ASGN2($1, $3, $4, $5);
                        fixpos($$, $1);
                    }
                | primary_value tCOLON2 tCONSTANT tOP_ASGN arg
                    {
                        yyerror("constant re-assignment");
                        $$ = 0;
                    }
                | tCOLON3 tCONSTANT tOP_ASGN arg
                    {
                        yyerror("constant re-assignment");
                        $$ = 0;
                    }
                | backref tOP_ASGN arg
                    {
                        rb_backref_error($1, vps);
                        $$ = 0;
                    }
                | arg tDOT2 arg
                    {
                        value_expr($1);
                        value_expr($3);
                        $$ = NEW_DOT2($1, $3);
                    }
                | arg tDOT3 arg
                    {
                        value_expr($1);
                        value_expr($3);
                        $$ = NEW_DOT3($1, $3);
                    }
                | arg '+' arg
                    {
                        $$ = call_op($1, '+', 1, $3, vps);
                    }
                | arg '-' arg
                    {
                        $$ = call_op($1, '-', 1, $3, vps);
                    }
                | arg '*' arg
                    {
                        $$ = call_op($1, '*', 1, $3, vps);
                    }
                | arg '/' arg
                    {
                        $$ = call_op($1, '/', 1, $3, vps);
                    }
                | arg '%' arg
                    {
                        $$ = call_op($1, '%', 1, $3, vps);
                    }
                | arg tPOW arg
                    {
                        $$ = call_op($1, tPOW, 1, $3, vps);
                    }
                | tUMINUS_NUM tINTEGER tPOW arg
                    {
                        $$ = call_op(call_op($2, tPOW, 1, $4, vps), tUMINUS, 0, 0, vps);
                    }
                | tUMINUS_NUM tFLOAT tPOW arg
                    {
                        $$ = call_op(call_op($2, tPOW, 1, $4, vps), tUMINUS, 0, 0, vps);
                    }
                | tUPLUS arg
                    {
                        if ($2 && nd_type($2) == NODE_LIT) {
                            $$ = $2;
                        }
                        else {
                            $$ = call_op($2, tUPLUS, 0, 0, vps);
                        }
                    }
                | tUMINUS arg
                    {
                        $$ = call_op($2, tUMINUS, 0, 0, vps);
                    }
                | arg '|' arg
                    {
                        $$ = call_op($1, '|', 1, $3, vps);
                    }
                | arg '^' arg
                    {
                        $$ = call_op($1, '^', 1, $3, vps);
                    }
                | arg '&' arg
                    {
                        $$ = call_op($1, '&', 1, $3, vps);
                    }
                | arg tCMP arg
                    {
                        $$ = call_op($1, tCMP, 1, $3, vps);
                    }
                | arg '>' arg
                    {
                        $$ = call_op($1, '>', 1, $3, vps);
                    }
                | arg tGEQ arg
                    {
                        $$ = call_op($1, tGEQ, 1, $3, vps);
                    }
                | arg '<' arg
                    {
                        $$ = call_op($1, '<', 1, $3, vps);
                    }
                | arg tLEQ arg
                    {
                        $$ = call_op($1, tLEQ, 1, $3, vps);
                    }
                | arg tEQ arg
                    {
                        $$ = call_op($1, tEQ, 1, $3, vps);
                    }
                | arg tEQQ arg
                    {
                        $$ = call_op($1, tEQQ, 1, $3, vps);
                    }
                | arg tNEQ arg
                    {
                        $$ = NEW_NOT(call_op($1, tEQ, 1, $3, vps));
                    }
                | arg tMATCH arg
                    {
                        $$ = match_gen($1, $3, vps);
                    }
                | arg tNMATCH arg
                    {
                        $$ = NEW_NOT(match_gen($1, $3, vps));
                    }
                | '!' arg
                    {
                        $$ = NEW_NOT(cond($2, vps));
                    }
                | '~' arg
                    {
                        $$ = call_op($2, '~', 0, 0, vps);
                    }
                | arg tLSHFT arg
                    {
                        $$ = call_op($1, tLSHFT, 1, $3, vps);
                    }
                | arg tRSHFT arg
                    {
                        $$ = call_op($1, tRSHFT, 1, $3, vps);
                    }
                | arg tANDOP arg
                    {
                        $$ = logop(NODE_AND, $1, $3, vps);
                    }
                | arg tOROP arg
                    {
                        $$ = logop(NODE_OR, $1, $3, vps);
                    }
                | kDEFINED opt_nl {vps->in_defined = 1;} arg
                    {
                        vps->in_defined = 0;
                        $$ = NEW_DEFINED($4);
                    }
                | arg '?' {vps->ternary_colon++;} arg ':' arg
                    {
                        $$ = NEW_IF(cond($1, vps), $4, $6);
                        fixpos($$, $1);
                        vps->ternary_colon--;
                    }
                | primary
                    {
                        $$ = $1;
                    }
                ;

arg_value       : arg
                    {
                        value_expr($1);
                        $$ = $1;
                    }
                ;

aref_args       : none
                | command opt_nl
                    {
                        rb_warn("parenthesize argument(s) for future version");
                        $$ = NEW_LIST($1);
                    }
                | args trailer
                    {
                        $$ = $1;
                    }
                | args ',' tSTAR arg opt_nl
                    {
                        value_expr($4);
                        $$ = arg_concat(vps, $1, $4);
                    }
                | assocs trailer
                    {
                        $$ = NEW_LIST(NEW_HASH($1));
                    }
                | tSTAR arg opt_nl
                    {
                        value_expr($2);
                        $$ = NEW_NEWLINE(NEW_SPLAT($2));
                    }
                ;

paren_args      : '(' none ')'
                    {
                        $$ = $2;
                    }
                | '(' call_args opt_nl ')'
                    {
                        $$ = $2;
                    }
                | '(' block_call opt_nl ')'
                    {
                        rb_warn("parenthesize argument for future version");
                        $$ = NEW_LIST($2);
                    }
                | '(' args ',' block_call opt_nl ')'
                    {
                        rb_warn("parenthesize argument for future version");
                        $$ = list_append(vps, $2, $4);
                    }
                ;

opt_paren_args  : none
                | paren_args
                ;

call_args       : command
                    {
                        rb_warn("parenthesize argument(s) for future version");
                        $$ = NEW_LIST($1);
                    }
                | args opt_block_arg
                    {
                        $$ = arg_blk_pass($1, $2);
                    }
                | args ',' tSTAR arg_value opt_block_arg
                    {
                        $$ = arg_concat(vps, $1, $4);
                        $$ = arg_blk_pass($$, $5);
                    }
                | assocs opt_block_arg
                    {
                        $$ = NEW_LIST(NEW_HASH($1));
                        $$ = arg_blk_pass($$, $2);
                    }
                | assocs ',' tSTAR arg_value opt_block_arg
                    {
                        $$ = arg_concat(vps, NEW_LIST(NEW_HASH($1)), $4);
                        $$ = arg_blk_pass($$, $5);
                    }
                | args ',' assocs opt_block_arg
                    {
                        $$ = list_append(vps, $1, NEW_HASH($3));
                        $$ = arg_blk_pass($$, $4);
                    }
                | args ',' assocs ',' tSTAR arg opt_block_arg
                    {
                        value_expr($6);
                        $$ = arg_concat(vps, list_append(vps, $1, NEW_HASH($3)), $6);
                        $$ = arg_blk_pass($$, $7);
                    }
                | tSTAR arg_value opt_block_arg
                    {
                        $$ = arg_blk_pass(NEW_SPLAT($2), $3);
                    }
                | block_arg
                ;

call_args2      : arg_value ',' args opt_block_arg
                    {
                        $$ = arg_blk_pass(list_concat(NEW_LIST($1),$3), $4);
                    }
                | arg_value ',' block_arg
                    {
                        $$ = arg_blk_pass($1, $3);
                    }
                | arg_value ',' tSTAR arg_value opt_block_arg
                    {
                        $$ = arg_concat(vps, NEW_LIST($1), $4);
                        $$ = arg_blk_pass($$, $5);
                    }
                | arg_value ',' args ',' tSTAR arg_value opt_block_arg
                    {
                        $$ = arg_concat(vps, list_concat(NEW_LIST($1),$3), $6);
                        $$ = arg_blk_pass($$, $7);
                    }
                | assocs opt_block_arg
                    {
                        $$ = NEW_LIST(NEW_HASH($1));
                        $$ = arg_blk_pass($$, $2);
                    }
                | assocs ',' tSTAR arg_value opt_block_arg
                    {
                        $$ = arg_concat(vps, NEW_LIST(NEW_HASH($1)), $4);
                        $$ = arg_blk_pass($$, $5);
                    }
                | arg_value ',' assocs opt_block_arg
                    {
                        $$ = list_append(vps, NEW_LIST($1), NEW_HASH($3));
                        $$ = arg_blk_pass($$, $4);
                    }
                | arg_value ',' args ',' assocs opt_block_arg
                    {
                        $$ = list_append(vps, list_concat(NEW_LIST($1),$3), NEW_HASH($5));
                        $$ = arg_blk_pass($$, $6);
                    }
                | arg_value ',' assocs ',' tSTAR arg_value opt_block_arg
                    {
                        $$ = arg_concat(vps, list_append(vps, NEW_LIST($1), NEW_HASH($3)), $6);
                        $$ = arg_blk_pass($$, $7);
                    }
                | arg_value ',' args ',' assocs ',' tSTAR arg_value opt_block_arg
                    {
                        $$ = arg_concat(vps, list_append(vps,
                                        list_concat(NEW_LIST($1), $3), NEW_HASH($5)), $8);
                        $$ = arg_blk_pass($$, $9);
                    }
                | tSTAR arg_value opt_block_arg
                    {
                        $$ = arg_blk_pass(NEW_SPLAT($2), $3);
                    }
                | block_arg
                ;

command_args    :  {
                        $<num>$ = vps->cmdarg_stack;
                        CMDARG_PUSH(1);
                    }
                  open_args
                    {
                        /* CMDARG_POP() */
                        vps->cmdarg_stack = $<num…