Add comment to top of reentr.c and fix typos in other files

[perl5.git] / perly.y

diff --git a/perly.y b/perly.y
index b1e7f90..0d00b95 100644 (file)
--- a/perly.y
+++ b/perly.y
@@ -1,6 +1,6 @@
 /*    perly.y
  *
- *    Copyright (c) 1991-2002, Larry Wall
+ *    Copyright (c) 1991-2002, 2003, 2004 Larry Wall
  *
  *    You may distribute under the terms of either the GNU General Public
  *    License or the Artistic License, as specified in the README file.
@@ -12,44 +12,20 @@
  * All that is gold does not glitter, not all those who wander are lost.'
  */
 
-%{
-#include "EXTERN.h"
-#define PERL_IN_PERLY_C
-#include "perl.h"
-#ifdef EBCDIC
-#undef YYDEBUG
-#endif
-#define dep() deprecate("\"do\" to call subroutines")
-
-/* stuff included here to make perly_c.diff apply better */
-
-#define yydebug            PL_yydebug
-#define yynerrs            PL_yynerrs
-#define yyerrflag   PL_yyerrflag
-#define yychar     PL_yychar
-#define yyval      PL_yyval
-#define yylval     PL_yylval
-
-struct ysv {
-    short* yyss;
-    YYSTYPE* yyvs;
-    int oldyydebug;
-    int oldyynerrs;
-    int oldyyerrflag;
-    int oldyychar;
-    YYSTYPE oldyyval;
-    YYSTYPE oldyylval;
-};
-
-static void yydestruct(pTHX_ void *ptr);
-
-%}
+/* This file holds the grammar for the Perl language. If edited, you need
+ * to run regen_perly.pl, which re-creates the files perly.h, perly.tab
+ * and perly.act which are derived from this.
+ *
+ * The main job of of this grammar is to call the various newFOO()
+ * functions in op.c to build a syntax tree of OP structs.
+ * It relies on the lexer in toke.c to do the tokenizing.
+ */
 
-%start prog
+/*  Make the parser re-entrant. */
 
-%{
-#if 0 /* get this from perly.h instead */
-%}
+%pure_parser
+
+%start prog
 
 %union {
     I32        ival;
@@ -58,16 +34,6 @@ static void yydestruct(pTHX_ void *ptr);
     GV *gvval;
 }
 
-%{
-#endif /* 0 */
-
-#ifdef USE_PURE_BISON
-#define YYLEX_PARAM (&yychar)
-#define yylex yylex_r
-#endif
-
-%}
-
 %token <ival> '{'
 
 %token <opval> WORD METHOD FUNCMETH THING PMFUNC PRIVATEREF
@@ -83,7 +49,7 @@ static void yydestruct(pTHX_ void *ptr);
 %token COLONATTR
 
 %type <ival> prog decl format startsub startanonsub startformsub
-%type <ival> progstart remember mremember '&'
+%type <ival> progstart remember mremember '&' savescope
 %type <opval> block mblock lineseq line loop cond else
 %type <opval> expr term subscripted scalar ary hsh arylen star amper sideff
 %type <opval> argexpr nexpr texpr iexpr mexpr mnexpr mtexpr miexpr
@@ -144,9 +110,6 @@ remember:   /* NULL */      /* start a full lexical scope */
 
 progstart:
                {
-#if defined(YYDEBUG) && defined(DEBUGGING)
-                   yydebug = (DEBUG_p_TEST);
-#endif
                    PL_expect = XSTATE; $$ = block_start(TRUE);
                }
        ;
@@ -162,16 +125,20 @@ mremember:        /* NULL */      /* start a partial lexical scope */
                        { $$ = block_start(FALSE); }
        ;
 
+savescope:     /* NULL */      /* remember stack pos in case of error */
+               { $$ = PL_savestack_ix; }
+
 /* A collection of "lines" in the program */
 lineseq        :       /* NULL */
                        { $$ = Nullop; }
        |       lineseq decl
                        { $$ = $1; }
-       |       lineseq line
-                       {   $$ = append_list(OP_LINESEQ,
-                               (LISTOP*)$1, (LISTOP*)$2);
+       |       lineseq savescope line
+                       {   LEAVE_SCOPE($2);
+                           $$ = append_list(OP_LINESEQ,
+                               (LISTOP*)$1, (LISTOP*)$3);
                            PL_pad_reset_pending = TRUE;
-                           if ($1 && $2) PL_hints |= HINT_BLOCK_SCOPE; }
+                           if ($1 && $3) PL_hints |= HINT_BLOCK_SCOPE; }
        ;
 
 /* A "line" in the program */
@@ -404,8 +371,6 @@ subbody     :       block   { $$ = $1; }
 
 package :      PACKAGE WORD ';'
                        { package($2); }
-       |       PACKAGE ';'
-                       { package(Nullop); }
        ;
 
 use    :       USE startsub
@@ -479,7 +444,8 @@ method      :       METHOD
 subscripted:    star '{' expr ';' '}'        /* *main::{something} */
                         /* In this and all the hash accessors, ';' is
                          * provided by the tokeniser */
-                       { $$ = newBINOP(OP_GELEM, 0, $1, scalar($3)); }
+                       { $$ = newBINOP(OP_GELEM, 0, $1, scalar($3));
+                           PL_expect = XOPERATOR; }
        |       scalar '[' expr ']'          /* $array[$element] */
                        { $$ = newBINOP(OP_AELEM, 0, oopsAV($1), scalar($3)); }
        |       term ARROW '[' expr ']'      /* somearef->[$element] */
@@ -691,7 +657,7 @@ term        :       termbinop
                        { $$ = newUNOP(OP_NOT, 0, scalar($2)); }
        |       UNIOP                                /* Unary op, $_ implied */
                        { $$ = newOP($1, 0); }
-       |       UNIOP block                          /* eval { foo }, I *think* */
+       |       UNIOP block                          /* eval { foo } */
                        { $$ = newUNOP($1, 0, $2); }
        |       UNIOP term                           /* Unary op */
                        { $$ = newUNOP($1, 0, $2); }
@@ -709,9 +675,9 @@ term        :       termbinop
                        { $$ = newOP($1, OPf_SPECIAL); }
        |       FUNC1 '(' expr ')'                   /* not($foo) */
                        { $$ = newUNOP($1, 0, $3); }
-       |       PMFUNC '(' term ')'                  /* split (/foo/) */
+       |       PMFUNC '(' term ')'                  /* /foo/ */
                        { $$ = pmruntime($1, $3, Nullop); }
-       |       PMFUNC '(' term ',' term ')'         /* split (/foo/,$bar) */
+       |       PMFUNC '(' term ',' term ')'         /* s/foo/bar/ (or tr) */
                        { $$ = pmruntime($1, $3, $5); }
        |       WORD
        |       listop
@@ -793,13 +759,3 @@ indirob    :       WORD
        |       PRIVATEREF
                        { $$ = $1; }
        ;
-
-%% /* PROGRAM */
-
-/* more stuff added to make perly_c.diff easier to apply */
-
-#ifdef yyparse
-#undef yyparse
-#endif
-#define yyparse() Perl_yyparse(pTHX)
-