X-Git-Url: https://perl5.git.perl.org/perl5.git/blobdiff_plain/0e38ac7805aa91d94a5718273a06c051670207ca..2b4887303b3930e7022307ef8e74ca51b5132e32:/perly.c diff --git a/perly.c b/perly.c index 3624ca3..5a934dc 100644 --- a/perly.c +++ b/perly.c @@ -1,6 +1,7 @@ /* perly.c * - * Copyright (c) 2004, 2005, 2006, 2007, 2008 by Larry Wall and others + * Copyright (c) 2004, 2005, 2006, 2007, 2008, + * 2009, 2010, 2011 by Larry Wall and others * * You may distribute under the terms of either the GNU General Public * License or the Artistic License, as specified in the README file. @@ -34,12 +35,22 @@ typedef unsigned short int yytype_uint16; typedef short int yytype_int16; typedef signed char yysigned_char; +/* YYINITDEPTH -- initial size of the parser's stacks. */ +#define YYINITDEPTH 200 + +#ifdef YYDEBUG +# undef YYDEBUG +#endif #ifdef DEBUGGING # define YYDEBUG 1 #else # define YYDEBUG 0 #endif +#ifndef YY_NULL +# define YY_NULL 0 +#endif + /* contains all the parser state tables; auto-generated from perly.y */ #include "perly.tab" @@ -132,11 +143,6 @@ yy_stack_print (pTHX_ const yy_parser *parser) ); break; #ifndef PERL_IN_MADLY_C - case toketype_p_tkval: - PerlIO_printf(Perl_debug_log, " %8.8s", - ps->val.pval ? ps->val.pval : "(NULL)"); - break; - case toketype_i_tkval: #endif case toketype_ival: @@ -195,100 +201,15 @@ S_clear_yystack(pTHX_ const yy_parser *parser) yy_stack_frame *ps = parser->ps; int i = 0; - if (!parser->stack || ps == parser->stack) + if (!parser->stack) return; YYDPRINTF ((Perl_debug_log, "clearing the parse stack\n")); - /* Freeing ops on the stack, and the op_latefree / op_latefreed / - * op_attached flags: - * - * When we pop tokens off the stack during error recovery, or when - * we pop all the tokens off the stack after a die during a shift or - * reduce (i.e. Perl_croak somewhere in yylex() or in one of the - * newFOO() functions), then it's possible that some of these tokens are - * of type opval, pointing to an OP. All these ops are orphans; each is - * its own miniature subtree that has not yet been attached to a - * larger tree. In this case, we should clearly free the op (making - * sure, for each op we free that we have PL_comppad pointing to the - * right place for freeing any SVs attached to the op in threaded - * builds. - * - * However, there is a particular problem if we die in newFOO() called - * by a reducing action; e.g. - * - * foo : bar baz boz - * { $$ = newFOO($1,$2,$3) } - * - * where - * OP *newFOO { ....; if (...) croak; .... } - * - * In this case, when we come to clean bar baz and boz off the stack, - * we don't know whether newFOO() has already: - * * freed them - * * left them as is - * * attached them to part of a larger tree - * * attached them to PL_compcv - * * attached them to PL_compcv then freed it (as in BEGIN {die } ) - * - * To get round this problem, we set the flag op_latefree on every op - * that gets pushed onto the parser stack. If op_free() sees this - * flag, it clears the op and frees any children,, but *doesn't* free - * the op itself; instead it sets the op_latefreed flag. This means - * that we can safely call op_free() multiple times on each stack op. - * So, when clearing the stack, we first, for each op that was being - * reduced, call op_free with op_latefree=1. This ensures that all ops - * hanging off these op are freed, but the reducing ops themselces are - * just undefed. Then we set op_latefreed=0 on *all* ops on the stack - * and free them. A little thought should convince you that this - * two-part approach to the reducing ops should handle the first three - * cases above safely. - * - * In the case of attaching to PL_compcv (currently just newATTRSUB - * does this), then we set the op_attached flag on the op that has - * been so attached, then avoid doing the final op_free during - * cleanup, on the assumption that it will happen (or has already - * happened) when PL_compcv is freed. - * - * Note this is fairly fragile mechanism. A more robust approach - * would be to use two of these flag bits as 2-bit reference count - * field for each op, indicating whether it is pointed to from: - * * a parent op - * * the parser stack - * * a CV - * but this would involve reworking all code (core and external) that - * manipulate op trees. - * - * XXX DAPM 17/1/07 I've decided its too fragile for now, and so have - * disabled it */ - -#define DISABLE_STACK_FREE - - -#ifdef DISABLE_STACK_FREE for (i=0; i< parser->yylen; i++) { SvREFCNT_dec(ps[-i].compcv); } ps -= parser->yylen; -#else - /* clear any reducing ops (1st pass) */ - - for (i=0; i< parser->yylen; i++) { - LEAVE_SCOPE(ps[-i].savestack_ix); - if (yy_type_tab[yystos[ps[-i].state]] == toketype_opval - && ps[-i].val.opval) { - if ( ! (ps[-i].val.opval->op_attached - && !ps[-i].val.opval->op_latefreed)) - { - if (ps[-i].compcv != PL_compcv) { - PL_compcv = ps[-i].compcv; - PAD_SET_CUR_NOSAVE(CvPADLIST(PL_compcv), 1); - } - op_free(ps[-i].val.opval); - } - } - } -#endif /* now free whole the stack, including the just-reduced ops */ @@ -300,17 +221,16 @@ S_clear_yystack(pTHX_ const yy_parser *parser) if (ps->compcv != PL_compcv) { PL_compcv = ps->compcv; PAD_SET_CUR_NOSAVE(CvPADLIST(PL_compcv), 1); + PL_comppad_name = PadlistNAMES(CvPADLIST(PL_compcv)); } YYDPRINTF ((Perl_debug_log, "(freeing op)\n")); -#ifndef DISABLE_STACK_FREE - ps->val.opval->op_latefree = 0; - if (!(ps->val.opval->op_attached && !ps->val.opval->op_latefreed)) -#endif - op_free(ps->val.opval); + op_free(ps->val.opval); } SvREFCNT_dec(ps->compcv); ps--; } + + Safefree(parser->stack); } @@ -320,21 +240,21 @@ S_clear_yystack(pTHX_ const yy_parser *parser) int #ifdef PERL_IN_MADLY_C -Perl_madparse (pTHX) +Perl_madparse (pTHX_ int gramtype) #else -Perl_yyparse (pTHX) +Perl_yyparse (pTHX_ int gramtype) #endif { dVAR; - register int yystate; - register int yyn; + int yystate; + int yyn; int yyresult; /* Lookahead token as an internal (translated) token number. */ int yytoken = 0; - register yy_parser *parser; /* the parser object */ - register yy_stack_frame *ps; /* current parser stack frame */ + yy_parser *parser; /* the parser object */ + yy_stack_frame *ps; /* current parser stack frame */ #define YYPOPSTACK parser->ps = --ps #define YYPUSHSTACK parser->ps = ++ps @@ -346,16 +266,31 @@ Perl_yyparse (pTHX) #ifndef PERL_IN_MADLY_C # ifdef PERL_MAD if (PL_madskills) - return madparse(); + return madparse(gramtype); # endif #endif YYDPRINTF ((Perl_debug_log, "Starting parse\n")); parser = PL_parser; - ps = parser->ps; - ENTER; /* force parser stack cleanup before we return */ + ENTER; /* force parser state cleanup/restoration before we return */ + SAVEPPTR(parser->yylval.pval); + SAVEINT(parser->yychar); + SAVEINT(parser->yyerrstatus); + SAVEINT(parser->stack_size); + SAVEINT(parser->yylen); + SAVEVPTR(parser->stack); + SAVEVPTR(parser->ps); + + /* initialise state for this parse */ + parser->yychar = gramtype; + parser->yyerrstatus = 0; + parser->stack_size = YYINITDEPTH; + parser->yylen = 0; + Newx(parser->stack, YYINITDEPTH, yy_stack_frame); + ps = parser->ps = parser->stack; + ps->state = 0; SAVEDESTRUCTOR_X(S_clear_yystack, parser); /*------------------------------------------------------------. @@ -367,13 +302,6 @@ Perl_yyparse (pTHX) YYDPRINTF ((Perl_debug_log, "Entering state %d\n", yystate)); -#ifndef DISABLE_STACK_FREE - if (yy_type_tab[yystos[yystate]] == toketype_opval && ps->val.opval) { - ps->val.opval->op_latefree = 1; - ps->val.opval->op_latefreed = 0; - } -#endif - parser->yylen = 0; { @@ -414,9 +342,12 @@ Perl_yyparse (pTHX) parser->yychar = yylex(); #endif +/* perly.tab is shipped based on an ASCII system; if it were to be regenerated + * on a platform that doesn't use ASCII, this translation back would need to be + * removed */ # ifdef EBCDIC if (parser->yychar >= 0 && parser->yychar < 255) { - parser->yychar = NATIVE_TO_ASCII(parser->yychar); + parser->yychar = NATIVE_TO_LATIN1(parser->yychar); } # endif } @@ -530,20 +461,9 @@ Perl_yyparse (pTHX) } - /* any just-reduced ops with the op_latefreed flag cleared need to be - * freed; the rest need the flag resetting */ { int i; for (i=0; i< parser->yylen; i++) { -#ifndef DISABLE_STACK_FREE - if (yy_type_tab[yystos[ps[-i].state]] == toketype_opval - && ps[-i].val.opval) - { - ps[-i].val.opval->op_latefree = 0; - if (ps[-i].val.opval->op_latefreed) - op_free(ps[-i].val.opval); - } -#endif SvREFCNT_dec(ps[-i].compcv); } } @@ -604,7 +524,6 @@ Perl_yyparse (pTHX) PL_compcv = ps->compcv; PAD_SET_CUR_NOSAVE(CvPADLIST(PL_compcv), 1); } - ps->val.opval->op_latefree = 0; op_free(ps->val.opval); } SvREFCNT_dec(ps->compcv); @@ -614,8 +533,6 @@ Perl_yyparse (pTHX) } YYDSYMPRINTF ("Error: discarding", yytoken, &parser->yylval); - if (yy_type_tab[yytoken] == toketype_opval) - op_free(parser->yylval.opval); parser->yychar = YYEMPTY; } @@ -654,7 +571,6 @@ Perl_yyparse (pTHX) PL_compcv = ps->compcv; PAD_SET_CUR_NOSAVE(CvPADLIST(PL_compcv), 1); } - ps->val.opval->op_latefree = 0; op_free(ps->val.opval); } SvREFCNT_dec(ps->compcv); @@ -708,8 +624,8 @@ Perl_yyparse (pTHX) * Local variables: * c-indentation-style: bsd * c-basic-offset: 4 - * indent-tabs-mode: t + * indent-tabs-mode: nil * End: * - * ex: set ts=8 sts=4 sw=4 noet: + * ex: set ts=8 sts=4 sw=4 et: */