github.com/ader1990/go@v0.0.0-20140630135419-8c24447fa791/src/cmd/gc/go.y (about)

     1  // Copyright 2009 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  /*
     6   * Go language grammar.
     7   *
     8   * The Go semicolon rules are:
     9   *
    10   *  1. all statements and declarations are terminated by semicolons.
    11   *  2. semicolons can be omitted before a closing ) or }.
    12   *  3. semicolons are inserted by the lexer before a newline
    13   *      following a specific list of tokens.
    14   *
    15   * Rules #1 and #2 are accomplished by writing the lists as
    16   * semicolon-separated lists with an optional trailing semicolon.
    17   * Rule #3 is implemented in yylex.
    18   */
    19  
    20  %{
    21  #include <u.h>
    22  #include <stdio.h>	/* if we don't, bison will, and go.h re-#defines getc */
    23  #include <libc.h>
    24  #include "go.h"
    25  
    26  static void fixlbrace(int);
    27  %}
    28  %union	{
    29  	Node*		node;
    30  	NodeList*		list;
    31  	Type*		type;
    32  	Sym*		sym;
    33  	struct	Val	val;
    34  	int		i;
    35  }
    36  
    37  // |sed 's/.*	//' |9 fmt -l1 |sort |9 fmt -l50 | sed 's/^/%xxx		/'
    38  
    39  %token	<val>	LLITERAL
    40  %token	<i>	LASOP LCOLAS
    41  %token	<sym>	LBREAK LCASE LCHAN LCONST LCONTINUE LDDD
    42  %token	<sym>	LDEFAULT LDEFER LELSE LFALL LFOR LFUNC LGO LGOTO
    43  %token	<sym>	LIF LIMPORT LINTERFACE LMAP LNAME
    44  %token	<sym>	LPACKAGE LRANGE LRETURN LSELECT LSTRUCT LSWITCH
    45  %token	<sym>	LTYPE LVAR
    46  
    47  %token		LANDAND LANDNOT LBODY LCOMM LDEC LEQ LGE LGT
    48  %token		LIGNORE LINC LLE LLSH LLT LNE LOROR LRSH
    49  
    50  %type	<i>	lbrace import_here
    51  %type	<sym>	sym packname
    52  %type	<val>	oliteral
    53  
    54  %type	<node>	stmt ntype
    55  %type	<node>	arg_type
    56  %type	<node>	case caseblock
    57  %type	<node>	compound_stmt dotname embed expr complitexpr bare_complitexpr
    58  %type	<node>	expr_or_type
    59  %type	<node>	fndcl hidden_fndcl fnliteral
    60  %type	<node>	for_body for_header for_stmt if_header if_stmt non_dcl_stmt
    61  %type	<node>	interfacedcl keyval labelname name
    62  %type	<node>	name_or_type non_expr_type
    63  %type	<node>	new_name dcl_name oexpr typedclname
    64  %type	<node>	onew_name
    65  %type	<node>	osimple_stmt pexpr pexpr_no_paren
    66  %type	<node>	pseudocall range_stmt select_stmt
    67  %type	<node>	simple_stmt
    68  %type	<node>	switch_stmt uexpr
    69  %type	<node>	xfndcl typedcl start_complit
    70  
    71  %type	<list>	xdcl fnbody fnres loop_body dcl_name_list
    72  %type	<list>	new_name_list expr_list keyval_list braced_keyval_list expr_or_type_list xdcl_list
    73  %type	<list>	oexpr_list caseblock_list elseif elseif_list else stmt_list oarg_type_list_ocomma arg_type_list
    74  %type	<list>	interfacedcl_list vardcl vardcl_list structdcl structdcl_list
    75  %type	<list>	common_dcl constdcl constdcl1 constdcl_list typedcl_list
    76  
    77  %type	<node>	convtype comptype dotdotdot
    78  %type	<node>	indcl interfacetype structtype ptrtype
    79  %type	<node>	recvchantype non_recvchantype othertype fnret_type fntype
    80  
    81  %type	<sym>	hidden_importsym hidden_pkg_importsym
    82  
    83  %type	<node>	hidden_constant hidden_literal hidden_funarg
    84  %type	<node>	hidden_interfacedcl hidden_structdcl
    85  
    86  %type	<list>	hidden_funres
    87  %type	<list>	ohidden_funres
    88  %type	<list>	hidden_funarg_list ohidden_funarg_list
    89  %type	<list>	hidden_interfacedcl_list ohidden_interfacedcl_list
    90  %type	<list>	hidden_structdcl_list ohidden_structdcl_list
    91  
    92  %type	<type>	hidden_type hidden_type_misc hidden_pkgtype
    93  %type	<type>	hidden_type_func
    94  %type	<type>	hidden_type_recv_chan hidden_type_non_recv_chan
    95  
    96  %left		LCOMM	/* outside the usual hierarchy; here for good error messages */
    97  
    98  %left		LOROR
    99  %left		LANDAND
   100  %left		LEQ LNE LLE LGE LLT LGT
   101  %left		'+' '-' '|' '^'
   102  %left		'*' '/' '%' '&' LLSH LRSH LANDNOT
   103  
   104  /*
   105   * manual override of shift/reduce conflicts.
   106   * the general form is that we assign a precedence
   107   * to the token being shifted and then introduce
   108   * NotToken with lower precedence or PreferToToken with higher
   109   * and annotate the reducing rule accordingly.
   110   */
   111  %left		NotPackage
   112  %left		LPACKAGE
   113  
   114  %left		NotParen
   115  %left		'('
   116  
   117  %left		')'
   118  %left		PreferToRightParen
   119  
   120  %error-verbose
   121  
   122  %%
   123  file:
   124  	loadsys
   125  	package
   126  	imports
   127  	xdcl_list
   128  	{
   129  		xtop = concat(xtop, $4);
   130  	}
   131  
   132  package:
   133  	%prec NotPackage
   134  	{
   135  		prevlineno = lineno;
   136  		yyerror("package statement must be first");
   137  		errorexit();
   138  	}
   139  |	LPACKAGE sym ';'
   140  	{
   141  		mkpackage($2->name);
   142  	}
   143  
   144  /*
   145   * this loads the definitions for the low-level runtime functions,
   146   * so that the compiler can generate calls to them,
   147   * but does not make the name "runtime" visible as a package.
   148   */
   149  loadsys:
   150  	{
   151  		importpkg = runtimepkg;
   152  
   153  		if(debug['A'])
   154  			cannedimports("runtime.builtin", "package runtime\n\n$$\n\n");
   155  		else
   156  			cannedimports("runtime.builtin", runtimeimport);
   157  		curio.importsafe = 1;
   158  	}
   159  	import_package
   160  	import_there
   161  	{
   162  		importpkg = nil;
   163  	}
   164  
   165  imports:
   166  |	imports import ';'
   167  
   168  import:
   169  	LIMPORT import_stmt
   170  |	LIMPORT '(' import_stmt_list osemi ')'
   171  |	LIMPORT '(' ')'
   172  
   173  import_stmt:
   174  	import_here import_package import_there
   175  	{
   176  		Pkg *ipkg;
   177  		Sym *my;
   178  		Node *pack;
   179  		
   180  		ipkg = importpkg;
   181  		my = importmyname;
   182  		importpkg = nil;
   183  		importmyname = S;
   184  
   185  		if(my == nil)
   186  			my = lookup(ipkg->name);
   187  
   188  		pack = nod(OPACK, N, N);
   189  		pack->sym = my;
   190  		pack->pkg = ipkg;
   191  		pack->lineno = $1;
   192  
   193  		if(my->name[0] == '.') {
   194  			importdot(ipkg, pack);
   195  			break;
   196  		}
   197  		if(strcmp(my->name, "init") == 0) {
   198  			yyerror("cannot import package as init - init must be a func");
   199  			break;
   200  		}
   201  		if(my->name[0] == '_' && my->name[1] == '\0')
   202  			break;
   203  		if(my->def) {
   204  			lineno = $1;
   205  			redeclare(my, "as imported package name");
   206  		}
   207  		my->def = pack;
   208  		my->lastlineno = $1;
   209  		my->block = 1;	// at top level
   210  	}
   211  |	import_here import_there
   212  	{
   213  		// When an invalid import path is passed to importfile,
   214  		// it calls yyerror and then sets up a fake import with
   215  		// no package statement. This allows us to test more
   216  		// than one invalid import statement in a single file.
   217  		if(nerrors == 0)
   218  			fatal("phase error in import");
   219  	}
   220  
   221  import_stmt_list:
   222  	import_stmt
   223  |	import_stmt_list ';' import_stmt
   224  
   225  import_here:
   226  	LLITERAL
   227  	{
   228  		// import with original name
   229  		$$ = parserline();
   230  		importmyname = S;
   231  		importfile(&$1, $$);
   232  	}
   233  |	sym LLITERAL
   234  	{
   235  		// import with given name
   236  		$$ = parserline();
   237  		importmyname = $1;
   238  		importfile(&$2, $$);
   239  	}
   240  |	'.' LLITERAL
   241  	{
   242  		// import into my name space
   243  		$$ = parserline();
   244  		importmyname = lookup(".");
   245  		importfile(&$2, $$);
   246  	}
   247  
   248  import_package:
   249  	LPACKAGE LNAME import_safety ';'
   250  	{
   251  		if(importpkg->name == nil) {
   252  			importpkg->name = $2->name;
   253  			pkglookup($2->name, nil)->npkg++;
   254  		} else if(strcmp(importpkg->name, $2->name) != 0)
   255  			yyerror("conflicting names %s and %s for package \"%Z\"", importpkg->name, $2->name, importpkg->path);
   256  		importpkg->direct = 1;
   257  		importpkg->safe = curio.importsafe;
   258  
   259  		if(safemode && !curio.importsafe)
   260  			yyerror("cannot import unsafe package \"%Z\"", importpkg->path);
   261  	}
   262  
   263  import_safety:
   264  |	LNAME
   265  	{
   266  		if(strcmp($1->name, "safe") == 0)
   267  			curio.importsafe = 1;
   268  	}
   269  
   270  import_there:
   271  	{
   272  		defercheckwidth();
   273  	}
   274  	hidden_import_list '$' '$'
   275  	{
   276  		resumecheckwidth();
   277  		unimportfile();
   278  	}
   279  
   280  /*
   281   * declarations
   282   */
   283  xdcl:
   284  	{
   285  		yyerror("empty top-level declaration");
   286  		$$ = nil;
   287  	}
   288  |	common_dcl
   289  |	xfndcl
   290  	{
   291  		$$ = list1($1);
   292  	}
   293  |	non_dcl_stmt
   294  	{
   295  		yyerror("non-declaration statement outside function body");
   296  		$$ = nil;
   297  	}
   298  |	error
   299  	{
   300  		$$ = nil;
   301  	}
   302  
   303  common_dcl:
   304  	LVAR vardcl
   305  	{
   306  		$$ = $2;
   307  	}
   308  |	LVAR '(' vardcl_list osemi ')'
   309  	{
   310  		$$ = $3;
   311  	}
   312  |	LVAR '(' ')'
   313  	{
   314  		$$ = nil;
   315  	}
   316  |	lconst constdcl
   317  	{
   318  		$$ = $2;
   319  		iota = -100000;
   320  		lastconst = nil;
   321  	}
   322  |	lconst '(' constdcl osemi ')'
   323  	{
   324  		$$ = $3;
   325  		iota = -100000;
   326  		lastconst = nil;
   327  	}
   328  |	lconst '(' constdcl ';' constdcl_list osemi ')'
   329  	{
   330  		$$ = concat($3, $5);
   331  		iota = -100000;
   332  		lastconst = nil;
   333  	}
   334  |	lconst '(' ')'
   335  	{
   336  		$$ = nil;
   337  		iota = -100000;
   338  	}
   339  |	LTYPE typedcl
   340  	{
   341  		$$ = list1($2);
   342  	}
   343  |	LTYPE '(' typedcl_list osemi ')'
   344  	{
   345  		$$ = $3;
   346  	}
   347  |	LTYPE '(' ')'
   348  	{
   349  		$$ = nil;
   350  	}
   351  
   352  lconst:
   353  	LCONST
   354  	{
   355  		iota = 0;
   356  	}
   357  
   358  vardcl:
   359  	dcl_name_list ntype
   360  	{
   361  		$$ = variter($1, $2, nil);
   362  	}
   363  |	dcl_name_list ntype '=' expr_list
   364  	{
   365  		$$ = variter($1, $2, $4);
   366  	}
   367  |	dcl_name_list '=' expr_list
   368  	{
   369  		$$ = variter($1, nil, $3);
   370  	}
   371  
   372  constdcl:
   373  	dcl_name_list ntype '=' expr_list
   374  	{
   375  		$$ = constiter($1, $2, $4);
   376  	}
   377  |	dcl_name_list '=' expr_list
   378  	{
   379  		$$ = constiter($1, N, $3);
   380  	}
   381  
   382  constdcl1:
   383  	constdcl
   384  |	dcl_name_list ntype
   385  	{
   386  		$$ = constiter($1, $2, nil);
   387  	}
   388  |	dcl_name_list
   389  	{
   390  		$$ = constiter($1, N, nil);
   391  	}
   392  
   393  typedclname:
   394  	sym
   395  	{
   396  		// different from dclname because the name
   397  		// becomes visible right here, not at the end
   398  		// of the declaration.
   399  		$$ = typedcl0($1);
   400  	}
   401  
   402  typedcl:
   403  	typedclname ntype
   404  	{
   405  		$$ = typedcl1($1, $2, 1);
   406  	}
   407  
   408  simple_stmt:
   409  	expr
   410  	{
   411  		$$ = $1;
   412  
   413  		// These nodes do not carry line numbers.
   414  		// Since a bare name used as an expression is an error,
   415  		// introduce a wrapper node to give the correct line.
   416  		switch($$->op) {
   417  		case ONAME:
   418  		case ONONAME:
   419  		case OTYPE:
   420  		case OPACK:
   421  		case OLITERAL:
   422  			$$ = nod(OPAREN, $$, N);
   423  			$$->implicit = 1;
   424  			break;
   425  		}
   426  	}
   427  |	expr LASOP expr
   428  	{
   429  		$$ = nod(OASOP, $1, $3);
   430  		$$->etype = $2;			// rathole to pass opcode
   431  	}
   432  |	expr_list '=' expr_list
   433  	{
   434  		if($1->next == nil && $3->next == nil) {
   435  			// simple
   436  			$$ = nod(OAS, $1->n, $3->n);
   437  			break;
   438  		}
   439  		// multiple
   440  		$$ = nod(OAS2, N, N);
   441  		$$->list = $1;
   442  		$$->rlist = $3;
   443  	}
   444  |	expr_list LCOLAS expr_list
   445  	{
   446  		if($3->n->op == OTYPESW) {
   447  			$$ = nod(OTYPESW, N, $3->n->right);
   448  			if($3->next != nil)
   449  				yyerror("expr.(type) must be alone in list");
   450  			if($1->next != nil)
   451  				yyerror("argument count mismatch: %d = %d", count($1), 1);
   452  			else if(($1->n->op != ONAME && $1->n->op != OTYPE && $1->n->op != ONONAME) || isblank($1->n))
   453  				yyerror("invalid variable name %N in type switch", $1->n);
   454  			else
   455  				$$->left = dclname($1->n->sym);  // it's a colas, so must not re-use an oldname.
   456  			break;
   457  		}
   458  		$$ = colas($1, $3, $2);
   459  	}
   460  |	expr LINC
   461  	{
   462  		$$ = nod(OASOP, $1, nodintconst(1));
   463  		$$->etype = OADD;
   464  	}
   465  |	expr LDEC
   466  	{
   467  		$$ = nod(OASOP, $1, nodintconst(1));
   468  		$$->etype = OSUB;
   469  	}
   470  
   471  case:
   472  	LCASE expr_or_type_list ':'
   473  	{
   474  		Node *n, *nn;
   475  
   476  		// will be converted to OCASE
   477  		// right will point to next case
   478  		// done in casebody()
   479  		markdcl();
   480  		$$ = nod(OXCASE, N, N);
   481  		$$->list = $2;
   482  		if(typesw != N && typesw->right != N && (n=typesw->right->left) != N) {
   483  			// type switch - declare variable
   484  			nn = newname(n->sym);
   485  			declare(nn, dclcontext);
   486  			$$->nname = nn;
   487  
   488  			// keep track of the instances for reporting unused
   489  			nn->defn = typesw->right;
   490  		}
   491  	}
   492  |	LCASE expr_or_type_list '=' expr ':'
   493  	{
   494  		Node *n;
   495  
   496  		// will be converted to OCASE
   497  		// right will point to next case
   498  		// done in casebody()
   499  		markdcl();
   500  		$$ = nod(OXCASE, N, N);
   501  		if($2->next == nil)
   502  			n = nod(OAS, $2->n, $4);
   503  		else {
   504  			n = nod(OAS2, N, N);
   505  			n->list = $2;
   506  			n->rlist = list1($4);
   507  		}
   508  		$$->list = list1(n);
   509  	}
   510  |	LCASE expr_or_type_list LCOLAS expr ':'
   511  	{
   512  		// will be converted to OCASE
   513  		// right will point to next case
   514  		// done in casebody()
   515  		markdcl();
   516  		$$ = nod(OXCASE, N, N);
   517  		$$->list = list1(colas($2, list1($4), $3));
   518  	}
   519  |	LDEFAULT ':'
   520  	{
   521  		Node *n, *nn;
   522  
   523  		markdcl();
   524  		$$ = nod(OXCASE, N, N);
   525  		if(typesw != N && typesw->right != N && (n=typesw->right->left) != N) {
   526  			// type switch - declare variable
   527  			nn = newname(n->sym);
   528  			declare(nn, dclcontext);
   529  			$$->nname = nn;
   530  
   531  			// keep track of the instances for reporting unused
   532  			nn->defn = typesw->right;
   533  		}
   534  	}
   535  
   536  compound_stmt:
   537  	'{'
   538  	{
   539  		markdcl();
   540  	}
   541  	stmt_list '}'
   542  	{
   543  		if($3 == nil)
   544  			$$ = nod(OEMPTY, N, N);
   545  		else
   546  			$$ = liststmt($3);
   547  		popdcl();
   548  	}
   549  
   550  caseblock:
   551  	case
   552  	{
   553  		// If the last token read by the lexer was consumed
   554  		// as part of the case, clear it (parser has cleared yychar).
   555  		// If the last token read by the lexer was the lookahead
   556  		// leave it alone (parser has it cached in yychar).
   557  		// This is so that the stmt_list action doesn't look at
   558  		// the case tokens if the stmt_list is empty.
   559  		yylast = yychar;
   560  		$1->xoffset = block;
   561  	}
   562  	stmt_list
   563  	{
   564  		int last;
   565  
   566  		// This is the only place in the language where a statement
   567  		// list is not allowed to drop the final semicolon, because
   568  		// it's the only place where a statement list is not followed 
   569  		// by a closing brace.  Handle the error for pedantry.
   570  
   571  		// Find the final token of the statement list.
   572  		// yylast is lookahead; yyprev is last of stmt_list
   573  		last = yyprev;
   574  
   575  		if(last > 0 && last != ';' && yychar != '}')
   576  			yyerror("missing statement after label");
   577  		$$ = $1;
   578  		$$->nbody = $3;
   579  		popdcl();
   580  	}
   581  
   582  caseblock_list:
   583  	{
   584  		$$ = nil;
   585  	}
   586  |	caseblock_list caseblock
   587  	{
   588  		$$ = list($1, $2);
   589  	}
   590  
   591  loop_body:
   592  	LBODY
   593  	{
   594  		markdcl();
   595  	}
   596  	stmt_list '}'
   597  	{
   598  		$$ = $3;
   599  		popdcl();
   600  	}
   601  
   602  range_stmt:
   603  	expr_list '=' LRANGE expr
   604  	{
   605  		$$ = nod(ORANGE, N, $4);
   606  		$$->list = $1;
   607  		$$->etype = 0;	// := flag
   608  	}
   609  |	expr_list LCOLAS LRANGE expr
   610  	{
   611  		$$ = nod(ORANGE, N, $4);
   612  		$$->list = $1;
   613  		$$->colas = 1;
   614  		colasdefn($1, $$);
   615  	}
   616  
   617  for_header:
   618  	osimple_stmt ';' osimple_stmt ';' osimple_stmt
   619  	{
   620  		// init ; test ; incr
   621  		if($5 != N && $5->colas != 0)
   622  			yyerror("cannot declare in the for-increment");
   623  		$$ = nod(OFOR, N, N);
   624  		if($1 != N)
   625  			$$->ninit = list1($1);
   626  		$$->ntest = $3;
   627  		$$->nincr = $5;
   628  	}
   629  |	osimple_stmt
   630  	{
   631  		// normal test
   632  		$$ = nod(OFOR, N, N);
   633  		$$->ntest = $1;
   634  	}
   635  |	range_stmt
   636  
   637  for_body:
   638  	for_header loop_body
   639  	{
   640  		$$ = $1;
   641  		$$->nbody = concat($$->nbody, $2);
   642  	}
   643  
   644  for_stmt:
   645  	LFOR
   646  	{
   647  		markdcl();
   648  	}
   649  	for_body
   650  	{
   651  		$$ = $3;
   652  		popdcl();
   653  	}
   654  
   655  if_header:
   656  	osimple_stmt
   657  	{
   658  		// test
   659  		$$ = nod(OIF, N, N);
   660  		$$->ntest = $1;
   661  	}
   662  |	osimple_stmt ';' osimple_stmt
   663  	{
   664  		// init ; test
   665  		$$ = nod(OIF, N, N);
   666  		if($1 != N)
   667  			$$->ninit = list1($1);
   668  		$$->ntest = $3;
   669  	}
   670  
   671  /* IF cond body (ELSE IF cond body)* (ELSE block)? */
   672  if_stmt:
   673  	LIF
   674  	{
   675  		markdcl();
   676  	}
   677  	if_header
   678  	{
   679  		if($3->ntest == N)
   680  			yyerror("missing condition in if statement");
   681  	}
   682  	loop_body
   683  	{
   684  		$3->nbody = $5;
   685  	}
   686  	elseif_list else
   687  	{
   688  		Node *n;
   689  		NodeList *nn;
   690  
   691  		$$ = $3;
   692  		n = $3;
   693  		popdcl();
   694  		for(nn = concat($7, $8); nn; nn = nn->next) {
   695  			if(nn->n->op == OIF)
   696  				popdcl();
   697  			n->nelse = list1(nn->n);
   698  			n = nn->n;
   699  		}
   700  	}
   701  
   702  elseif:
   703  	LELSE LIF 
   704  	{
   705  		markdcl();
   706  	}
   707  	if_header loop_body
   708  	{
   709  		if($4->ntest == N)
   710  			yyerror("missing condition in if statement");
   711  		$4->nbody = $5;
   712  		$$ = list1($4);
   713  	}
   714  
   715  elseif_list:
   716  	{
   717  		$$ = nil;
   718  	}
   719  |	elseif_list elseif
   720  	{
   721  		$$ = concat($1, $2);
   722  	}
   723  
   724  else:
   725  	{
   726  		$$ = nil;
   727  	}
   728  |	LELSE compound_stmt
   729  	{
   730  		NodeList *node;
   731  		
   732  		node = mal(sizeof *node);
   733  		node->n = $2;
   734  		node->end = node;
   735  		$$ = node;
   736  	}
   737  
   738  switch_stmt:
   739  	LSWITCH
   740  	{
   741  		markdcl();
   742  	}
   743  	if_header
   744  	{
   745  		Node *n;
   746  		n = $3->ntest;
   747  		if(n != N && n->op != OTYPESW)
   748  			n = N;
   749  		typesw = nod(OXXX, typesw, n);
   750  	}
   751  	LBODY caseblock_list '}'
   752  	{
   753  		$$ = $3;
   754  		$$->op = OSWITCH;
   755  		$$->list = $6;
   756  		typesw = typesw->left;
   757  		popdcl();
   758  	}
   759  
   760  select_stmt:
   761  	LSELECT
   762  	{
   763  		typesw = nod(OXXX, typesw, N);
   764  	}
   765  	LBODY caseblock_list '}'
   766  	{
   767  		$$ = nod(OSELECT, N, N);
   768  		$$->lineno = typesw->lineno;
   769  		$$->list = $4;
   770  		typesw = typesw->left;
   771  	}
   772  
   773  /*
   774   * expressions
   775   */
   776  expr:
   777  	uexpr
   778  |	expr LOROR expr
   779  	{
   780  		$$ = nod(OOROR, $1, $3);
   781  	}
   782  |	expr LANDAND expr
   783  	{
   784  		$$ = nod(OANDAND, $1, $3);
   785  	}
   786  |	expr LEQ expr
   787  	{
   788  		$$ = nod(OEQ, $1, $3);
   789  	}
   790  |	expr LNE expr
   791  	{
   792  		$$ = nod(ONE, $1, $3);
   793  	}
   794  |	expr LLT expr
   795  	{
   796  		$$ = nod(OLT, $1, $3);
   797  	}
   798  |	expr LLE expr
   799  	{
   800  		$$ = nod(OLE, $1, $3);
   801  	}
   802  |	expr LGE expr
   803  	{
   804  		$$ = nod(OGE, $1, $3);
   805  	}
   806  |	expr LGT expr
   807  	{
   808  		$$ = nod(OGT, $1, $3);
   809  	}
   810  |	expr '+' expr
   811  	{
   812  		$$ = nod(OADD, $1, $3);
   813  	}
   814  |	expr '-' expr
   815  	{
   816  		$$ = nod(OSUB, $1, $3);
   817  	}
   818  |	expr '|' expr
   819  	{
   820  		$$ = nod(OOR, $1, $3);
   821  	}
   822  |	expr '^' expr
   823  	{
   824  		$$ = nod(OXOR, $1, $3);
   825  	}
   826  |	expr '*' expr
   827  	{
   828  		$$ = nod(OMUL, $1, $3);
   829  	}
   830  |	expr '/' expr
   831  	{
   832  		$$ = nod(ODIV, $1, $3);
   833  	}
   834  |	expr '%' expr
   835  	{
   836  		$$ = nod(OMOD, $1, $3);
   837  	}
   838  |	expr '&' expr
   839  	{
   840  		$$ = nod(OAND, $1, $3);
   841  	}
   842  |	expr LANDNOT expr
   843  	{
   844  		$$ = nod(OANDNOT, $1, $3);
   845  	}
   846  |	expr LLSH expr
   847  	{
   848  		$$ = nod(OLSH, $1, $3);
   849  	}
   850  |	expr LRSH expr
   851  	{
   852  		$$ = nod(ORSH, $1, $3);
   853  	}
   854  	/* not an expression anymore, but left in so we can give a good error */
   855  |	expr LCOMM expr
   856  	{
   857  		$$ = nod(OSEND, $1, $3);
   858  	}
   859  
   860  uexpr:
   861  	pexpr
   862  |	'*' uexpr
   863  	{
   864  		$$ = nod(OIND, $2, N);
   865  	}
   866  |	'&' uexpr
   867  	{
   868  		if($2->op == OCOMPLIT) {
   869  			// Special case for &T{...}: turn into (*T){...}.
   870  			$$ = $2;
   871  			$$->right = nod(OIND, $$->right, N);
   872  			$$->right->implicit = 1;
   873  		} else {
   874  			$$ = nod(OADDR, $2, N);
   875  		}
   876  	}
   877  |	'+' uexpr
   878  	{
   879  		$$ = nod(OPLUS, $2, N);
   880  	}
   881  |	'-' uexpr
   882  	{
   883  		$$ = nod(OMINUS, $2, N);
   884  	}
   885  |	'!' uexpr
   886  	{
   887  		$$ = nod(ONOT, $2, N);
   888  	}
   889  |	'~' uexpr
   890  	{
   891  		yyerror("the bitwise complement operator is ^");
   892  		$$ = nod(OCOM, $2, N);
   893  	}
   894  |	'^' uexpr
   895  	{
   896  		$$ = nod(OCOM, $2, N);
   897  	}
   898  |	LCOMM uexpr
   899  	{
   900  		$$ = nod(ORECV, $2, N);
   901  	}
   902  
   903  /*
   904   * call-like statements that
   905   * can be preceded by 'defer' and 'go'
   906   */
   907  pseudocall:
   908  	pexpr '(' ')'
   909  	{
   910  		$$ = nod(OCALL, $1, N);
   911  	}
   912  |	pexpr '(' expr_or_type_list ocomma ')'
   913  	{
   914  		$$ = nod(OCALL, $1, N);
   915  		$$->list = $3;
   916  	}
   917  |	pexpr '(' expr_or_type_list LDDD ocomma ')'
   918  	{
   919  		$$ = nod(OCALL, $1, N);
   920  		$$->list = $3;
   921  		$$->isddd = 1;
   922  	}
   923  
   924  pexpr_no_paren:
   925  	LLITERAL
   926  	{
   927  		$$ = nodlit($1);
   928  	}
   929  |	name
   930  |	pexpr '.' sym
   931  	{
   932  		if($1->op == OPACK) {
   933  			Sym *s;
   934  			s = restrictlookup($3->name, $1->pkg);
   935  			$1->used = 1;
   936  			$$ = oldname(s);
   937  			break;
   938  		}
   939  		$$ = nod(OXDOT, $1, newname($3));
   940  	}
   941  |	pexpr '.' '(' expr_or_type ')'
   942  	{
   943  		$$ = nod(ODOTTYPE, $1, $4);
   944  	}
   945  |	pexpr '.' '(' LTYPE ')'
   946  	{
   947  		$$ = nod(OTYPESW, N, $1);
   948  	}
   949  |	pexpr '[' expr ']'
   950  	{
   951  		$$ = nod(OINDEX, $1, $3);
   952  	}
   953  |	pexpr '[' oexpr ':' oexpr ']'
   954  	{
   955  		$$ = nod(OSLICE, $1, nod(OKEY, $3, $5));
   956  	}
   957  |	pexpr '[' oexpr ':' oexpr ':' oexpr ']'
   958  	{
   959  		if($5 == N)
   960  			yyerror("middle index required in 3-index slice");
   961  		if($7 == N)
   962  			yyerror("final index required in 3-index slice");
   963  		$$ = nod(OSLICE3, $1, nod(OKEY, $3, nod(OKEY, $5, $7)));
   964  	}
   965  |	pseudocall
   966  |	convtype '(' expr ocomma ')'
   967  	{
   968  		// conversion
   969  		$$ = nod(OCALL, $1, N);
   970  		$$->list = list1($3);
   971  	}
   972  |	comptype lbrace start_complit braced_keyval_list '}'
   973  	{
   974  		$$ = $3;
   975  		$$->right = $1;
   976  		$$->list = $4;
   977  		fixlbrace($2);
   978  	}
   979  |	pexpr_no_paren '{' start_complit braced_keyval_list '}'
   980  	{
   981  		$$ = $3;
   982  		$$->right = $1;
   983  		$$->list = $4;
   984  	}
   985  |	'(' expr_or_type ')' '{' start_complit braced_keyval_list '}'
   986  	{
   987  		yyerror("cannot parenthesize type in composite literal");
   988  		$$ = $5;
   989  		$$->right = $2;
   990  		$$->list = $6;
   991  	}
   992  |	fnliteral
   993  
   994  start_complit:
   995  	{
   996  		// composite expression.
   997  		// make node early so we get the right line number.
   998  		$$ = nod(OCOMPLIT, N, N);
   999  	}
  1000  
  1001  keyval:
  1002  	expr ':' complitexpr
  1003  	{
  1004  		$$ = nod(OKEY, $1, $3);
  1005  	}
  1006  
  1007  bare_complitexpr:
  1008  	expr
  1009  	{
  1010  		// These nodes do not carry line numbers.
  1011  		// Since a composite literal commonly spans several lines,
  1012  		// the line number on errors may be misleading.
  1013  		// Introduce a wrapper node to give the correct line.
  1014  		$$ = $1;
  1015  		switch($$->op) {
  1016  		case ONAME:
  1017  		case ONONAME:
  1018  		case OTYPE:
  1019  		case OPACK:
  1020  		case OLITERAL:
  1021  			$$ = nod(OPAREN, $$, N);
  1022  			$$->implicit = 1;
  1023  		}
  1024  	}
  1025  |	'{' start_complit braced_keyval_list '}'
  1026  	{
  1027  		$$ = $2;
  1028  		$$->list = $3;
  1029  	}
  1030  
  1031  complitexpr:
  1032  	expr
  1033  |	'{' start_complit braced_keyval_list '}'
  1034  	{
  1035  		$$ = $2;
  1036  		$$->list = $3;
  1037  	}
  1038  
  1039  pexpr:
  1040  	pexpr_no_paren
  1041  |	'(' expr_or_type ')'
  1042  	{
  1043  		$$ = $2;
  1044  		
  1045  		// Need to know on lhs of := whether there are ( ).
  1046  		// Don't bother with the OPAREN in other cases:
  1047  		// it's just a waste of memory and time.
  1048  		switch($$->op) {
  1049  		case ONAME:
  1050  		case ONONAME:
  1051  		case OPACK:
  1052  		case OTYPE:
  1053  		case OLITERAL:
  1054  		case OTYPESW:
  1055  			$$ = nod(OPAREN, $$, N);
  1056  		}
  1057  	}
  1058  
  1059  expr_or_type:
  1060  	expr
  1061  |	non_expr_type	%prec PreferToRightParen
  1062  
  1063  name_or_type:
  1064  	ntype
  1065  
  1066  lbrace:
  1067  	LBODY
  1068  	{
  1069  		$$ = LBODY;
  1070  	}
  1071  |	'{'
  1072  	{
  1073  		$$ = '{';
  1074  	}
  1075  
  1076  /*
  1077   * names and types
  1078   *	newname is used before declared
  1079   *	oldname is used after declared
  1080   */
  1081  new_name:
  1082  	sym
  1083  	{
  1084  		if($1 == S)
  1085  			$$ = N;
  1086  		else
  1087  			$$ = newname($1);
  1088  	}
  1089  
  1090  dcl_name:
  1091  	sym
  1092  	{
  1093  		$$ = dclname($1);
  1094  	}
  1095  
  1096  onew_name:
  1097  	{
  1098  		$$ = N;
  1099  	}
  1100  |	new_name
  1101  
  1102  sym:
  1103  	LNAME
  1104  	{
  1105  		$$ = $1;
  1106  		// during imports, unqualified non-exported identifiers are from builtinpkg
  1107  		if(importpkg != nil && !exportname($1->name))
  1108  			$$ = pkglookup($1->name, builtinpkg);
  1109  	}
  1110  |	hidden_importsym
  1111  |	'?'
  1112  	{
  1113  		$$ = S;
  1114  	}
  1115  
  1116  hidden_importsym:
  1117  	'@' LLITERAL '.' LNAME
  1118  	{
  1119  		Pkg *p;
  1120  
  1121  		if($2.u.sval->len == 0)
  1122  			p = importpkg;
  1123  		else {
  1124  			if(isbadimport($2.u.sval))
  1125  				errorexit();
  1126  			p = mkpkg($2.u.sval);
  1127  		}
  1128  		$$ = pkglookup($4->name, p);
  1129  	}
  1130  |	'@' LLITERAL '.' '?'
  1131  	{
  1132  		Pkg *p;
  1133  
  1134  		if($2.u.sval->len == 0)
  1135  			p = importpkg;
  1136  		else {
  1137  			if(isbadimport($2.u.sval))
  1138  				errorexit();
  1139  			p = mkpkg($2.u.sval);
  1140  		}
  1141  		$$ = pkglookup("?", p);
  1142  	}
  1143  
  1144  name:
  1145  	sym	%prec NotParen
  1146  	{
  1147  		$$ = oldname($1);
  1148  		if($$->pack != N)
  1149  			$$->pack->used = 1;
  1150  	}
  1151  
  1152  labelname:
  1153  	new_name
  1154  
  1155  /*
  1156   * to avoid parsing conflicts, type is split into
  1157   *	channel types
  1158   *	function types
  1159   *	parenthesized types
  1160   *	any other type
  1161   * the type system makes additional restrictions,
  1162   * but those are not implemented in the grammar.
  1163   */
  1164  dotdotdot:
  1165  	LDDD
  1166  	{
  1167  		yyerror("final argument in variadic function missing type");
  1168  		$$ = nod(ODDD, typenod(typ(TINTER)), N);
  1169  	}
  1170  |	LDDD ntype
  1171  	{
  1172  		$$ = nod(ODDD, $2, N);
  1173  	}
  1174  
  1175  ntype:
  1176  	recvchantype
  1177  |	fntype
  1178  |	othertype
  1179  |	ptrtype
  1180  |	dotname
  1181  |	'(' ntype ')'
  1182  	{
  1183  		$$ = nod(OTPAREN, $2, N);
  1184  	}
  1185  
  1186  non_expr_type:
  1187  	recvchantype
  1188  |	fntype
  1189  |	othertype
  1190  |	'*' non_expr_type
  1191  	{
  1192  		$$ = nod(OIND, $2, N);
  1193  	}
  1194  
  1195  non_recvchantype:
  1196  	fntype
  1197  |	othertype
  1198  |	ptrtype
  1199  |	dotname
  1200  |	'(' ntype ')'
  1201  	{
  1202  		$$ = nod(OTPAREN, $2, N);
  1203  	}
  1204  
  1205  convtype:
  1206  	fntype
  1207  |	othertype
  1208  
  1209  comptype:
  1210  	othertype
  1211  
  1212  fnret_type:
  1213  	recvchantype
  1214  |	fntype
  1215  |	othertype
  1216  |	ptrtype
  1217  |	dotname
  1218  
  1219  dotname:
  1220  	name
  1221  |	name '.' sym
  1222  	{
  1223  		if($1->op == OPACK) {
  1224  			Sym *s;
  1225  			s = restrictlookup($3->name, $1->pkg);
  1226  			$1->used = 1;
  1227  			$$ = oldname(s);
  1228  			break;
  1229  		}
  1230  		$$ = nod(OXDOT, $1, newname($3));
  1231  	}
  1232  
  1233  othertype:
  1234  	'[' oexpr ']' ntype
  1235  	{
  1236  		$$ = nod(OTARRAY, $2, $4);
  1237  	}
  1238  |	'[' LDDD ']' ntype
  1239  	{
  1240  		// array literal of nelem
  1241  		$$ = nod(OTARRAY, nod(ODDD, N, N), $4);
  1242  	}
  1243  |	LCHAN non_recvchantype
  1244  	{
  1245  		$$ = nod(OTCHAN, $2, N);
  1246  		$$->etype = Cboth;
  1247  	}
  1248  |	LCHAN LCOMM ntype
  1249  	{
  1250  		$$ = nod(OTCHAN, $3, N);
  1251  		$$->etype = Csend;
  1252  	}
  1253  |	LMAP '[' ntype ']' ntype
  1254  	{
  1255  		$$ = nod(OTMAP, $3, $5);
  1256  	}
  1257  |	structtype
  1258  |	interfacetype
  1259  
  1260  ptrtype:
  1261  	'*' ntype
  1262  	{
  1263  		$$ = nod(OIND, $2, N);
  1264  	}
  1265  
  1266  recvchantype:
  1267  	LCOMM LCHAN ntype
  1268  	{
  1269  		$$ = nod(OTCHAN, $3, N);
  1270  		$$->etype = Crecv;
  1271  	}
  1272  
  1273  structtype:
  1274  	LSTRUCT lbrace structdcl_list osemi '}'
  1275  	{
  1276  		$$ = nod(OTSTRUCT, N, N);
  1277  		$$->list = $3;
  1278  		fixlbrace($2);
  1279  	}
  1280  |	LSTRUCT lbrace '}'
  1281  	{
  1282  		$$ = nod(OTSTRUCT, N, N);
  1283  		fixlbrace($2);
  1284  	}
  1285  
  1286  interfacetype:
  1287  	LINTERFACE lbrace interfacedcl_list osemi '}'
  1288  	{
  1289  		$$ = nod(OTINTER, N, N);
  1290  		$$->list = $3;
  1291  		fixlbrace($2);
  1292  	}
  1293  |	LINTERFACE lbrace '}'
  1294  	{
  1295  		$$ = nod(OTINTER, N, N);
  1296  		fixlbrace($2);
  1297  	}
  1298  
  1299  /*
  1300   * function stuff
  1301   * all in one place to show how crappy it all is
  1302   */
  1303  xfndcl:
  1304  	LFUNC fndcl fnbody
  1305  	{
  1306  		$$ = $2;
  1307  		if($$ == N)
  1308  			break;
  1309  		if(noescape && $3 != nil)
  1310  			yyerror("can only use //go:noescape with external func implementations");
  1311  		$$->nbody = $3;
  1312  		$$->endlineno = lineno;
  1313  		$$->noescape = noescape;
  1314  		funcbody($$);
  1315  	}
  1316  
  1317  fndcl:
  1318  	sym '(' oarg_type_list_ocomma ')' fnres
  1319  	{
  1320  		Node *t;
  1321  
  1322  		$$ = N;
  1323  		$3 = checkarglist($3, 1);
  1324  
  1325  		if(strcmp($1->name, "init") == 0) {
  1326  			$1 = renameinit();
  1327  			if($3 != nil || $5 != nil)
  1328  				yyerror("func init must have no arguments and no return values");
  1329  		}
  1330  		if(strcmp(localpkg->name, "main") == 0 && strcmp($1->name, "main") == 0) {
  1331  			if($3 != nil || $5 != nil)
  1332  				yyerror("func main must have no arguments and no return values");
  1333  		}
  1334  
  1335  		t = nod(OTFUNC, N, N);
  1336  		t->list = $3;
  1337  		t->rlist = $5;
  1338  
  1339  		$$ = nod(ODCLFUNC, N, N);
  1340  		$$->nname = newname($1);
  1341  		$$->nname->defn = $$;
  1342  		$$->nname->ntype = t;		// TODO: check if nname already has an ntype
  1343  		declare($$->nname, PFUNC);
  1344  
  1345  		funchdr($$);
  1346  	}
  1347  |	'(' oarg_type_list_ocomma ')' sym '(' oarg_type_list_ocomma ')' fnres
  1348  	{
  1349  		Node *rcvr, *t;
  1350  
  1351  		$$ = N;
  1352  		$2 = checkarglist($2, 0);
  1353  		$6 = checkarglist($6, 1);
  1354  
  1355  		if($2 == nil) {
  1356  			yyerror("method has no receiver");
  1357  			break;
  1358  		}
  1359  		if($2->next != nil) {
  1360  			yyerror("method has multiple receivers");
  1361  			break;
  1362  		}
  1363  		rcvr = $2->n;
  1364  		if(rcvr->op != ODCLFIELD) {
  1365  			yyerror("bad receiver in method");
  1366  			break;
  1367  		}
  1368  		if(rcvr->right->op == OTPAREN || (rcvr->right->op == OIND && rcvr->right->left->op == OTPAREN))
  1369  			yyerror("cannot parenthesize receiver type");
  1370  
  1371  		t = nod(OTFUNC, rcvr, N);
  1372  		t->list = $6;
  1373  		t->rlist = $8;
  1374  
  1375  		$$ = nod(ODCLFUNC, N, N);
  1376  		$$->shortname = newname($4);
  1377  		$$->nname = methodname1($$->shortname, rcvr->right);
  1378  		$$->nname->defn = $$;
  1379  		$$->nname->ntype = t;
  1380  		$$->nname->nointerface = nointerface;
  1381  		declare($$->nname, PFUNC);
  1382  
  1383  		funchdr($$);
  1384  	}
  1385  
  1386  hidden_fndcl:
  1387  	hidden_pkg_importsym '(' ohidden_funarg_list ')' ohidden_funres
  1388  	{
  1389  		Sym *s;
  1390  		Type *t;
  1391  
  1392  		$$ = N;
  1393  
  1394  		s = $1;
  1395  		t = functype(N, $3, $5);
  1396  
  1397  		importsym(s, ONAME);
  1398  		if(s->def != N && s->def->op == ONAME) {
  1399  			if(eqtype(t, s->def->type)) {
  1400  				dclcontext = PDISCARD;  // since we skip funchdr below
  1401  				break;
  1402  			}
  1403  			yyerror("inconsistent definition for func %S during import\n\t%T\n\t%T", s, s->def->type, t);
  1404  		}
  1405  
  1406  		$$ = newname(s);
  1407  		$$->type = t;
  1408  		declare($$, PFUNC);
  1409  
  1410  		funchdr($$);
  1411  	}
  1412  |	'(' hidden_funarg_list ')' sym '(' ohidden_funarg_list ')' ohidden_funres
  1413  	{
  1414  		$$ = methodname1(newname($4), $2->n->right); 
  1415  		$$->type = functype($2->n, $6, $8);
  1416  
  1417  		checkwidth($$->type);
  1418  		addmethod($4, $$->type, 0, nointerface);
  1419  		nointerface = 0;
  1420  		funchdr($$);
  1421  		
  1422  		// inl.c's inlnode in on a dotmeth node expects to find the inlineable body as
  1423  		// (dotmeth's type)->nname->inl, and dotmeth's type has been pulled
  1424  		// out by typecheck's lookdot as this $$->ttype.  So by providing
  1425  		// this back link here we avoid special casing there.
  1426  		$$->type->nname = $$;
  1427  	}
  1428  
  1429  fntype:
  1430  	LFUNC '(' oarg_type_list_ocomma ')' fnres
  1431  	{
  1432  		$3 = checkarglist($3, 1);
  1433  		$$ = nod(OTFUNC, N, N);
  1434  		$$->list = $3;
  1435  		$$->rlist = $5;
  1436  	}
  1437  
  1438  fnbody:
  1439  	{
  1440  		$$ = nil;
  1441  	}
  1442  |	'{' stmt_list '}'
  1443  	{
  1444  		$$ = $2;
  1445  		if($$ == nil)
  1446  			$$ = list1(nod(OEMPTY, N, N));
  1447  	}
  1448  
  1449  fnres:
  1450  	%prec NotParen
  1451  	{
  1452  		$$ = nil;
  1453  	}
  1454  |	fnret_type
  1455  	{
  1456  		$$ = list1(nod(ODCLFIELD, N, $1));
  1457  	}
  1458  |	'(' oarg_type_list_ocomma ')'
  1459  	{
  1460  		$2 = checkarglist($2, 0);
  1461  		$$ = $2;
  1462  	}
  1463  
  1464  fnlitdcl:
  1465  	fntype
  1466  	{
  1467  		closurehdr($1);
  1468  	}
  1469  
  1470  fnliteral:
  1471  	fnlitdcl lbrace stmt_list '}'
  1472  	{
  1473  		$$ = closurebody($3);
  1474  		fixlbrace($2);
  1475  	}
  1476  |	fnlitdcl error
  1477  	{
  1478  		$$ = closurebody(nil);
  1479  	}
  1480  
  1481  /*
  1482   * lists of things
  1483   * note that they are left recursive
  1484   * to conserve yacc stack. they need to
  1485   * be reversed to interpret correctly
  1486   */
  1487  xdcl_list:
  1488  	{
  1489  		$$ = nil;
  1490  	}
  1491  |	xdcl_list xdcl ';'
  1492  	{
  1493  		$$ = concat($1, $2);
  1494  		if(nsyntaxerrors == 0)
  1495  			testdclstack();
  1496  		nointerface = 0;
  1497  		noescape = 0;
  1498  	}
  1499  
  1500  vardcl_list:
  1501  	vardcl
  1502  |	vardcl_list ';' vardcl
  1503  	{
  1504  		$$ = concat($1, $3);
  1505  	}
  1506  
  1507  constdcl_list:
  1508  	constdcl1
  1509  |	constdcl_list ';' constdcl1
  1510  	{
  1511  		$$ = concat($1, $3);
  1512  	}
  1513  
  1514  typedcl_list:
  1515  	typedcl
  1516  	{
  1517  		$$ = list1($1);
  1518  	}
  1519  |	typedcl_list ';' typedcl
  1520  	{
  1521  		$$ = list($1, $3);
  1522  	}
  1523  
  1524  structdcl_list:
  1525  	structdcl
  1526  |	structdcl_list ';' structdcl
  1527  	{
  1528  		$$ = concat($1, $3);
  1529  	}
  1530  
  1531  interfacedcl_list:
  1532  	interfacedcl
  1533  	{
  1534  		$$ = list1($1);
  1535  	}
  1536  |	interfacedcl_list ';' interfacedcl
  1537  	{
  1538  		$$ = list($1, $3);
  1539  	}
  1540  
  1541  structdcl:
  1542  	new_name_list ntype oliteral
  1543  	{
  1544  		NodeList *l;
  1545  
  1546  		Node *n;
  1547  		l = $1;
  1548  		if(l == nil) {
  1549  			// ? symbol, during import (list1(N) == nil)
  1550  			n = $2;
  1551  			if(n->op == OIND)
  1552  				n = n->left;
  1553  			n = embedded(n->sym, importpkg);
  1554  			n->right = $2;
  1555  			n->val = $3;
  1556  			$$ = list1(n);
  1557  			break;
  1558  		}
  1559  
  1560  		for(l=$1; l; l=l->next) {
  1561  			l->n = nod(ODCLFIELD, l->n, $2);
  1562  			l->n->val = $3;
  1563  		}
  1564  	}
  1565  |	embed oliteral
  1566  	{
  1567  		$1->val = $2;
  1568  		$$ = list1($1);
  1569  	}
  1570  |	'(' embed ')' oliteral
  1571  	{
  1572  		$2->val = $4;
  1573  		$$ = list1($2);
  1574  		yyerror("cannot parenthesize embedded type");
  1575  	}
  1576  |	'*' embed oliteral
  1577  	{
  1578  		$2->right = nod(OIND, $2->right, N);
  1579  		$2->val = $3;
  1580  		$$ = list1($2);
  1581  	}
  1582  |	'(' '*' embed ')' oliteral
  1583  	{
  1584  		$3->right = nod(OIND, $3->right, N);
  1585  		$3->val = $5;
  1586  		$$ = list1($3);
  1587  		yyerror("cannot parenthesize embedded type");
  1588  	}
  1589  |	'*' '(' embed ')' oliteral
  1590  	{
  1591  		$3->right = nod(OIND, $3->right, N);
  1592  		$3->val = $5;
  1593  		$$ = list1($3);
  1594  		yyerror("cannot parenthesize embedded type");
  1595  	}
  1596  
  1597  packname:
  1598  	LNAME
  1599  	{
  1600  		Node *n;
  1601  
  1602  		$$ = $1;
  1603  		n = oldname($1);
  1604  		if(n->pack != N)
  1605  			n->pack->used = 1;
  1606  	}
  1607  |	LNAME '.' sym
  1608  	{
  1609  		Pkg *pkg;
  1610  
  1611  		if($1->def == N || $1->def->op != OPACK) {
  1612  			yyerror("%S is not a package", $1);
  1613  			pkg = localpkg;
  1614  		} else {
  1615  			$1->def->used = 1;
  1616  			pkg = $1->def->pkg;
  1617  		}
  1618  		$$ = restrictlookup($3->name, pkg);
  1619  	}
  1620  
  1621  embed:
  1622  	packname
  1623  	{
  1624  		$$ = embedded($1, localpkg);
  1625  	}
  1626  
  1627  interfacedcl:
  1628  	new_name indcl
  1629  	{
  1630  		$$ = nod(ODCLFIELD, $1, $2);
  1631  		ifacedcl($$);
  1632  	}
  1633  |	packname
  1634  	{
  1635  		$$ = nod(ODCLFIELD, N, oldname($1));
  1636  	}
  1637  |	'(' packname ')'
  1638  	{
  1639  		$$ = nod(ODCLFIELD, N, oldname($2));
  1640  		yyerror("cannot parenthesize embedded type");
  1641  	}
  1642  
  1643  indcl:
  1644  	'(' oarg_type_list_ocomma ')' fnres
  1645  	{
  1646  		// without func keyword
  1647  		$2 = checkarglist($2, 1);
  1648  		$$ = nod(OTFUNC, fakethis(), N);
  1649  		$$->list = $2;
  1650  		$$->rlist = $4;
  1651  	}
  1652  
  1653  /*
  1654   * function arguments.
  1655   */
  1656  arg_type:
  1657  	name_or_type
  1658  |	sym name_or_type
  1659  	{
  1660  		$$ = nod(ONONAME, N, N);
  1661  		$$->sym = $1;
  1662  		$$ = nod(OKEY, $$, $2);
  1663  	}
  1664  |	sym dotdotdot
  1665  	{
  1666  		$$ = nod(ONONAME, N, N);
  1667  		$$->sym = $1;
  1668  		$$ = nod(OKEY, $$, $2);
  1669  	}
  1670  |	dotdotdot
  1671  
  1672  arg_type_list:
  1673  	arg_type
  1674  	{
  1675  		$$ = list1($1);
  1676  	}
  1677  |	arg_type_list ',' arg_type
  1678  	{
  1679  		$$ = list($1, $3);
  1680  	}
  1681  
  1682  oarg_type_list_ocomma:
  1683  	{
  1684  		$$ = nil;
  1685  	}
  1686  |	arg_type_list ocomma
  1687  	{
  1688  		$$ = $1;
  1689  	}
  1690  
  1691  /*
  1692   * statement
  1693   */
  1694  stmt:
  1695  	{
  1696  		$$ = N;
  1697  	}
  1698  |	compound_stmt
  1699  |	common_dcl
  1700  	{
  1701  		$$ = liststmt($1);
  1702  	}
  1703  |	non_dcl_stmt
  1704  |	error
  1705  	{
  1706  		$$ = N;
  1707  	}
  1708  
  1709  non_dcl_stmt:
  1710  	simple_stmt
  1711  |	for_stmt
  1712  |	switch_stmt
  1713  |	select_stmt
  1714  |	if_stmt
  1715  |	labelname ':'
  1716  	{
  1717  		$1 = nod(OLABEL, $1, N);
  1718  		$1->sym = dclstack;  // context, for goto restrictions
  1719  	}
  1720  	stmt
  1721  	{
  1722  		NodeList *l;
  1723  
  1724  		$1->defn = $4;
  1725  		l = list1($1);
  1726  		if($4)
  1727  			l = list(l, $4);
  1728  		$$ = liststmt(l);
  1729  	}
  1730  |	LFALL
  1731  	{
  1732  		// will be converted to OFALL
  1733  		$$ = nod(OXFALL, N, N);
  1734  		$$->xoffset = block;
  1735  	}
  1736  |	LBREAK onew_name
  1737  	{
  1738  		$$ = nod(OBREAK, $2, N);
  1739  	}
  1740  |	LCONTINUE onew_name
  1741  	{
  1742  		$$ = nod(OCONTINUE, $2, N);
  1743  	}
  1744  |	LGO pseudocall
  1745  	{
  1746  		$$ = nod(OPROC, $2, N);
  1747  	}
  1748  |	LDEFER pseudocall
  1749  	{
  1750  		$$ = nod(ODEFER, $2, N);
  1751  	}
  1752  |	LGOTO new_name
  1753  	{
  1754  		$$ = nod(OGOTO, $2, N);
  1755  		$$->sym = dclstack;  // context, for goto restrictions
  1756  	}
  1757  |	LRETURN oexpr_list
  1758  	{
  1759  		$$ = nod(ORETURN, N, N);
  1760  		$$->list = $2;
  1761  		if($$->list == nil && curfn != N) {
  1762  			NodeList *l;
  1763  
  1764  			for(l=curfn->dcl; l; l=l->next) {
  1765  				if(l->n->class == PPARAM)
  1766  					continue;
  1767  				if(l->n->class != PPARAMOUT)
  1768  					break;
  1769  				if(l->n->sym->def != l->n)
  1770  					yyerror("%s is shadowed during return", l->n->sym->name);
  1771  			}
  1772  		}
  1773  	}
  1774  
  1775  stmt_list:
  1776  	stmt
  1777  	{
  1778  		$$ = nil;
  1779  		if($1 != N)
  1780  			$$ = list1($1);
  1781  	}
  1782  |	stmt_list ';' stmt
  1783  	{
  1784  		$$ = $1;
  1785  		if($3 != N)
  1786  			$$ = list($$, $3);
  1787  	}
  1788  
  1789  new_name_list:
  1790  	new_name
  1791  	{
  1792  		$$ = list1($1);
  1793  	}
  1794  |	new_name_list ',' new_name
  1795  	{
  1796  		$$ = list($1, $3);
  1797  	}
  1798  
  1799  dcl_name_list:
  1800  	dcl_name
  1801  	{
  1802  		$$ = list1($1);
  1803  	}
  1804  |	dcl_name_list ',' dcl_name
  1805  	{
  1806  		$$ = list($1, $3);
  1807  	}
  1808  
  1809  expr_list:
  1810  	expr
  1811  	{
  1812  		$$ = list1($1);
  1813  	}
  1814  |	expr_list ',' expr
  1815  	{
  1816  		$$ = list($1, $3);
  1817  	}
  1818  
  1819  expr_or_type_list:
  1820  	expr_or_type
  1821  	{
  1822  		$$ = list1($1);
  1823  	}
  1824  |	expr_or_type_list ',' expr_or_type
  1825  	{
  1826  		$$ = list($1, $3);
  1827  	}
  1828  
  1829  /*
  1830   * list of combo of keyval and val
  1831   */
  1832  keyval_list:
  1833  	keyval
  1834  	{
  1835  		$$ = list1($1);
  1836  	}
  1837  |	bare_complitexpr
  1838  	{
  1839  		$$ = list1($1);
  1840  	}
  1841  |	keyval_list ',' keyval
  1842  	{
  1843  		$$ = list($1, $3);
  1844  	}
  1845  |	keyval_list ',' bare_complitexpr
  1846  	{
  1847  		$$ = list($1, $3);
  1848  	}
  1849  
  1850  braced_keyval_list:
  1851  	{
  1852  		$$ = nil;
  1853  	}
  1854  |	keyval_list ocomma
  1855  	{
  1856  		$$ = $1;
  1857  	}
  1858  
  1859  /*
  1860   * optional things
  1861   */
  1862  osemi:
  1863  |	';'
  1864  
  1865  ocomma:
  1866  |	','
  1867  
  1868  oexpr:
  1869  	{
  1870  		$$ = N;
  1871  	}
  1872  |	expr
  1873  
  1874  oexpr_list:
  1875  	{
  1876  		$$ = nil;
  1877  	}
  1878  |	expr_list
  1879  
  1880  osimple_stmt:
  1881  	{
  1882  		$$ = N;
  1883  	}
  1884  |	simple_stmt
  1885  
  1886  ohidden_funarg_list:
  1887  	{
  1888  		$$ = nil;
  1889  	}
  1890  |	hidden_funarg_list
  1891  
  1892  ohidden_structdcl_list:
  1893  	{
  1894  		$$ = nil;
  1895  	}
  1896  |	hidden_structdcl_list
  1897  
  1898  ohidden_interfacedcl_list:
  1899  	{
  1900  		$$ = nil;
  1901  	}
  1902  |	hidden_interfacedcl_list
  1903  
  1904  oliteral:
  1905  	{
  1906  		$$.ctype = CTxxx;
  1907  	}
  1908  |	LLITERAL
  1909  
  1910  /*
  1911   * import syntax from package header
  1912   */
  1913  hidden_import:
  1914  	LIMPORT LNAME LLITERAL ';'
  1915  	{
  1916  		importimport($2, $3.u.sval);
  1917  	}
  1918  |	LVAR hidden_pkg_importsym hidden_type ';'
  1919  	{
  1920  		importvar($2, $3);
  1921  	}
  1922  |	LCONST hidden_pkg_importsym '=' hidden_constant ';'
  1923  	{
  1924  		importconst($2, types[TIDEAL], $4);
  1925  	}
  1926  |	LCONST hidden_pkg_importsym hidden_type '=' hidden_constant ';'
  1927  	{
  1928  		importconst($2, $3, $5);
  1929  	}
  1930  |	LTYPE hidden_pkgtype hidden_type ';'
  1931  	{
  1932  		importtype($2, $3);
  1933  	}
  1934  |	LFUNC hidden_fndcl fnbody ';'
  1935  	{
  1936  		if($2 == N) {
  1937  			dclcontext = PEXTERN;  // since we skip the funcbody below
  1938  			break;
  1939  		}
  1940  
  1941  		$2->inl = $3;
  1942  
  1943  		funcbody($2);
  1944  		importlist = list(importlist, $2);
  1945  
  1946  		if(debug['E']) {
  1947  			print("import [%Z] func %lN \n", importpkg->path, $2);
  1948  			if(debug['m'] > 2 && $2->inl)
  1949  				print("inl body:%+H\n", $2->inl);
  1950  		}
  1951  	}
  1952  
  1953  hidden_pkg_importsym:
  1954  	hidden_importsym
  1955  	{
  1956  		$$ = $1;
  1957  		structpkg = $$->pkg;
  1958  	}
  1959  
  1960  hidden_pkgtype:
  1961  	hidden_pkg_importsym
  1962  	{
  1963  		$$ = pkgtype($1);
  1964  		importsym($1, OTYPE);
  1965  	}
  1966  
  1967  /*
  1968   *  importing types
  1969   */
  1970  
  1971  hidden_type:
  1972  	hidden_type_misc
  1973  |	hidden_type_recv_chan
  1974  |	hidden_type_func
  1975  
  1976  hidden_type_non_recv_chan:
  1977  	hidden_type_misc
  1978  |	hidden_type_func
  1979  
  1980  hidden_type_misc:
  1981  	hidden_importsym
  1982  	{
  1983  		$$ = pkgtype($1);
  1984  	}
  1985  |	LNAME
  1986  	{
  1987  		// predefined name like uint8
  1988  		$1 = pkglookup($1->name, builtinpkg);
  1989  		if($1->def == N || $1->def->op != OTYPE) {
  1990  			yyerror("%s is not a type", $1->name);
  1991  			$$ = T;
  1992  		} else
  1993  			$$ = $1->def->type;
  1994  	}
  1995  |	'[' ']' hidden_type
  1996  	{
  1997  		$$ = aindex(N, $3);
  1998  	}
  1999  |	'[' LLITERAL ']' hidden_type
  2000  	{
  2001  		$$ = aindex(nodlit($2), $4);
  2002  	}
  2003  |	LMAP '[' hidden_type ']' hidden_type
  2004  	{
  2005  		$$ = maptype($3, $5);
  2006  	}
  2007  |	LSTRUCT '{' ohidden_structdcl_list '}'
  2008  	{
  2009  		$$ = tostruct($3);
  2010  	}
  2011  |	LINTERFACE '{' ohidden_interfacedcl_list '}'
  2012  	{
  2013  		$$ = tointerface($3);
  2014  	}
  2015  |	'*' hidden_type
  2016  	{
  2017  		$$ = ptrto($2);
  2018  	}
  2019  |	LCHAN hidden_type_non_recv_chan
  2020  	{
  2021  		$$ = typ(TCHAN);
  2022  		$$->type = $2;
  2023  		$$->chan = Cboth;
  2024  	}
  2025  |	LCHAN '(' hidden_type_recv_chan ')'
  2026  	{
  2027  		$$ = typ(TCHAN);
  2028  		$$->type = $3;
  2029  		$$->chan = Cboth;
  2030  	}
  2031  |	LCHAN LCOMM hidden_type
  2032  	{
  2033  		$$ = typ(TCHAN);
  2034  		$$->type = $3;
  2035  		$$->chan = Csend;
  2036  	}
  2037  
  2038  hidden_type_recv_chan:
  2039  	LCOMM LCHAN hidden_type
  2040  	{
  2041  		$$ = typ(TCHAN);
  2042  		$$->type = $3;
  2043  		$$->chan = Crecv;
  2044  	}
  2045  
  2046  hidden_type_func:
  2047  	LFUNC '(' ohidden_funarg_list ')' ohidden_funres
  2048  	{
  2049  		$$ = functype(nil, $3, $5);
  2050  	}
  2051  
  2052  hidden_funarg:
  2053  	sym hidden_type oliteral
  2054  	{
  2055  		$$ = nod(ODCLFIELD, N, typenod($2));
  2056  		if($1)
  2057  			$$->left = newname($1);
  2058  		$$->val = $3;
  2059  	}
  2060  |	sym LDDD hidden_type oliteral
  2061  	{
  2062  		Type *t;
  2063  	
  2064  		t = typ(TARRAY);
  2065  		t->bound = -1;
  2066  		t->type = $3;
  2067  
  2068  		$$ = nod(ODCLFIELD, N, typenod(t));
  2069  		if($1)
  2070  			$$->left = newname($1);
  2071  		$$->isddd = 1;
  2072  		$$->val = $4;
  2073  	}
  2074  
  2075  hidden_structdcl:
  2076  	sym hidden_type oliteral
  2077  	{
  2078  		Sym *s;
  2079  		Pkg *p;
  2080  
  2081  		if($1 != S && strcmp($1->name, "?") != 0) {
  2082  			$$ = nod(ODCLFIELD, newname($1), typenod($2));
  2083  			$$->val = $3;
  2084  		} else {
  2085  			s = $2->sym;
  2086  			if(s == S && isptr[$2->etype])
  2087  				s = $2->type->sym;
  2088  			p = importpkg;
  2089  			if($1 != S)
  2090  				p = $1->pkg;
  2091  			$$ = embedded(s, p);
  2092  			$$->right = typenod($2);
  2093  			$$->val = $3;
  2094  		}
  2095  	}
  2096  
  2097  hidden_interfacedcl:
  2098  	sym '(' ohidden_funarg_list ')' ohidden_funres
  2099  	{
  2100  		$$ = nod(ODCLFIELD, newname($1), typenod(functype(fakethis(), $3, $5)));
  2101  	}
  2102  |	hidden_type
  2103  	{
  2104  		$$ = nod(ODCLFIELD, N, typenod($1));
  2105  	}
  2106  
  2107  ohidden_funres:
  2108  	{
  2109  		$$ = nil;
  2110  	}
  2111  |	hidden_funres
  2112  
  2113  hidden_funres:
  2114  	'(' ohidden_funarg_list ')'
  2115  	{
  2116  		$$ = $2;
  2117  	}
  2118  |	hidden_type
  2119  	{
  2120  		$$ = list1(nod(ODCLFIELD, N, typenod($1)));
  2121  	}
  2122  
  2123  /*
  2124   *  importing constants
  2125   */
  2126  
  2127  hidden_literal:
  2128  	LLITERAL
  2129  	{
  2130  		$$ = nodlit($1);
  2131  	}
  2132  |	'-' LLITERAL
  2133  	{
  2134  		$$ = nodlit($2);
  2135  		switch($$->val.ctype){
  2136  		case CTINT:
  2137  		case CTRUNE:
  2138  			mpnegfix($$->val.u.xval);
  2139  			break;
  2140  		case CTFLT:
  2141  			mpnegflt($$->val.u.fval);
  2142  			break;
  2143  		case CTCPLX:
  2144  			mpnegflt(&$$->val.u.cval->real);
  2145  			mpnegflt(&$$->val.u.cval->imag);
  2146  			break;
  2147  		default:
  2148  			yyerror("bad negated constant");
  2149  		}
  2150  	}
  2151  |	sym
  2152  	{
  2153  		$$ = oldname(pkglookup($1->name, builtinpkg));
  2154  		if($$->op != OLITERAL)
  2155  			yyerror("bad constant %S", $$->sym);
  2156  	}
  2157  
  2158  hidden_constant:
  2159  	hidden_literal
  2160  |	'(' hidden_literal '+' hidden_literal ')'
  2161  	{
  2162  		if($2->val.ctype == CTRUNE && $4->val.ctype == CTINT) {
  2163  			$$ = $2;
  2164  			mpaddfixfix($2->val.u.xval, $4->val.u.xval, 0);
  2165  			break;
  2166  		}
  2167  		$4->val.u.cval->real = $4->val.u.cval->imag;
  2168  		mpmovecflt(&$4->val.u.cval->imag, 0.0);
  2169  		$$ = nodcplxlit($2->val, $4->val);
  2170  	}
  2171  
  2172  hidden_import_list:
  2173  |	hidden_import_list hidden_import
  2174  
  2175  hidden_funarg_list:
  2176  	hidden_funarg
  2177  	{
  2178  		$$ = list1($1);
  2179  	}
  2180  |	hidden_funarg_list ',' hidden_funarg
  2181  	{
  2182  		$$ = list($1, $3);
  2183  	}
  2184  
  2185  hidden_structdcl_list:
  2186  	hidden_structdcl
  2187  	{
  2188  		$$ = list1($1);
  2189  	}
  2190  |	hidden_structdcl_list ';' hidden_structdcl
  2191  	{
  2192  		$$ = list($1, $3);
  2193  	}
  2194  
  2195  hidden_interfacedcl_list:
  2196  	hidden_interfacedcl
  2197  	{
  2198  		$$ = list1($1);
  2199  	}
  2200  |	hidden_interfacedcl_list ';' hidden_interfacedcl
  2201  	{
  2202  		$$ = list($1, $3);
  2203  	}
  2204  
  2205  %%
  2206  
  2207  static void
  2208  fixlbrace(int lbr)
  2209  {
  2210  	// If the opening brace was an LBODY,
  2211  	// set up for another one now that we're done.
  2212  	// See comment in lex.c about loophack.
  2213  	if(lbr == LBODY)
  2214  		loophack = 1;
  2215  }
  2216