This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
disable problematical 'uninitialized value' warning tests
[perl5.git] / toke.c
diff --git a/toke.c b/toke.c
index 74499ab..e8c1073 100644 (file)
--- a/toke.c
+++ b/toke.c
@@ -1,6 +1,7 @@
 /*    toke.c
  *
- *    Copyright (c) 1991-2002, Larry Wall
+ *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
+ *    2000, 2001, 2002, 2003, 2004, 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.
@@ -22,8 +23,8 @@
 #define PERL_IN_TOKE_C
 #include "perl.h"
 
-#define yychar PL_yychar
-#define yylval PL_yylval
+#define yychar (*PL_yycharp)
+#define yylval (*PL_yylvalp)
 
 static char ident_too_long[] = "Identifier too long";
 static char c_without_g[] = "Use of /c modifier is meaningless without /g";
@@ -78,22 +79,6 @@ static I32 utf16rev_textfilter(pTHX_ int idx, SV *sv, int maxlen);
 #undef ff_next
 #endif
 
-#ifdef USE_PURE_BISON
-#  ifndef YYMAXLEVEL
-#    define YYMAXLEVEL 100
-#  endif
-YYSTYPE* yylval_pointer[YYMAXLEVEL];
-int* yychar_pointer[YYMAXLEVEL];
-int yyactlevel = -1;
-#  undef yylval
-#  undef yychar
-#  define yylval (*yylval_pointer[yyactlevel])
-#  define yychar (*yychar_pointer[yyactlevel])
-#  define PERL_YYLEX_PARAM yylval_pointer[yyactlevel],yychar_pointer[yyactlevel]
-#  undef yylex
-#  define yylex()      Perl_yylex_r(aTHX_ yylval_pointer[yyactlevel],yychar_pointer[yyactlevel])
-#endif
-
 #include "keywords.h"
 
 /* CLINE is a macro that ensures PL_copline has a sane value */
@@ -255,18 +240,23 @@ S_no_op(pTHX_ char *what, char *s)
     else
        PL_bufptr = s;
     yywarn(Perl_form(aTHX_ "%s found where operator expected", what));
-    if (is_first)
-       Perl_warn(aTHX_ "\t(Missing semicolon on previous line?)\n");
-    else if (PL_oldoldbufptr && isIDFIRST_lazy_if(PL_oldoldbufptr,UTF)) {
-       char *t;
-       for (t = PL_oldoldbufptr; *t && (isALNUM_lazy_if(t,UTF) || *t == ':'); t++) ;
-       if (t < PL_bufptr && isSPACE(*t))
-           Perl_warn(aTHX_ "\t(Do you need to predeclare %.*s?)\n",
-               t - PL_oldoldbufptr, PL_oldoldbufptr);
-    }
-    else {
-       assert(s >= oldbp);
-       Perl_warn(aTHX_ "\t(Missing operator before %.*s?)\n", s - oldbp, oldbp);
+    if (ckWARN_d(WARN_SYNTAX)) {
+       if (is_first)
+           Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
+                   "\t(Missing semicolon on previous line?)\n");
+       else if (PL_oldoldbufptr && isIDFIRST_lazy_if(PL_oldoldbufptr,UTF)) {
+           char *t;
+           for (t = PL_oldoldbufptr; *t && (isALNUM_lazy_if(t,UTF) || *t == ':'); t++) ;
+           if (t < PL_bufptr && isSPACE(*t))
+               Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
+                       "\t(Do you need to predeclare %.*s?)\n",
+                   t - PL_oldoldbufptr, PL_oldoldbufptr);
+       }
+       else {
+           assert(s >= oldbp);
+           Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
+                   "\t(Missing operator before %.*s?)\n", s - oldbp, oldbp);
+       }
     }
     PL_bufptr = oldbp;
 }
@@ -681,7 +671,7 @@ S_check_uni(pTHX)
         char ch = *s;
         *s = '\0';
         Perl_warner(aTHX_ packWARN(WARN_AMBIGUOUS),
-                  "Warning: Use of \"%s\" without parens is ambiguous",
+                  "Warning: Use of \"%s\" without parentheses is ambiguous",
                   PL_last_uni);
         *s = ch;
     }
@@ -785,6 +775,8 @@ S_force_word(pTHX_ register char *start, int token, int check_keyword, int allow
        }
        PL_nextval[PL_nexttoke].opval = (OP*)newSVOP(OP_CONST,0, newSVpv(PL_tokenbuf,0));
        PL_nextval[PL_nexttoke].opval->op_private |= OPpCONST_BARE;
+       if (UTF && !IN_BYTES && is_utf8_string((U8*)PL_tokenbuf, len))
+           SvUTF8_on(((SVOP*)PL_nextval[PL_nexttoke].opval)->op_sv);
        force_next(token);
     }
     return s;
@@ -1228,7 +1220,7 @@ S_scan_const(pTHX_ char *start)
 
     const char *leaveit =      /* set of acceptably-backslashed characters */
        PL_lex_inpat
-           ? "\\.^$@AGZdDwWsSbBpPXC+*?|()-nrtfeaxcz0123456789[{]} \t\n\r\f\v#"
+           ? "\\.^$@AGZdDwWsSbBpPXC+*?|()-nrtfeaxz0123456789[{]} \t\n\r\f\v#"
            : "";
 
     if (PL_lex_inwhat == OP_TRANS && PL_sublex_info.sub_op) {
@@ -1321,7 +1313,7 @@ S_scan_const(pTHX_ char *start)
           except for the last char, which will be done separately. */
        else if (*s == '(' && PL_lex_inpat && s[1] == '?') {
            if (s[2] == '#') {
-               while (s < send && *s != ')')
+               while (s+1 < send && *s != ')')
                    *d++ = NATIVE_TO_NEED(has_utf8,*s++);
            }
            else if (s[2] == '{' /* This should match regcomp.c */
@@ -1340,10 +1332,8 @@ S_scan_const(pTHX_ char *start)
                        count--;
                    regparse++;
                }
-               if (*regparse != ')') {
+               if (*regparse != ')')
                    regparse--;         /* Leave one char for continuation. */
-                   yyerror("Sequence (?{...}) not terminated or not {}-balanced");
-               }
                while (s < regparse)
                    *d++ = NATIVE_TO_NEED(has_utf8,*s++);
            }
@@ -2141,7 +2131,7 @@ S_find_in_my_stash(pTHX_ char *pkgname, I32 len)
 #ifdef DEBUGGING
     static char* exp_name[] =
        { "OPERATOR", "TERM", "REF", "STATE", "BLOCK", "ATTRBLOCK",
-         "ATTRTERM", "TERMBLOCK"
+         "ATTRTERM", "TERMBLOCK", "TERMORDORDOR"
        };
 #endif
 
@@ -2170,26 +2160,6 @@ S_find_in_my_stash(pTHX_ char *pkgname, I32 len)
       if we already built the token before, use it.
 */
 
-#ifdef USE_PURE_BISON
-int
-Perl_yylex_r(pTHX_ YYSTYPE *lvalp, int *lcharp)
-{
-    int r;
-
-    yyactlevel++;
-    yylval_pointer[yyactlevel] = lvalp;
-    yychar_pointer[yyactlevel] = lcharp;
-    if (yyactlevel >= YYMAXLEVEL)
-       Perl_croak(aTHX_ "panic: YYMAXLEVEL");
-
-    r = Perl_yylex(aTHX);
-
-    if (yyactlevel > 0)
-       yyactlevel--;
-
-    return r;
-}
-#endif
 
 #ifdef __SC__
 #pragma segment Perl_yylex
@@ -2426,8 +2396,12 @@ Perl_yylex(pTHX)
        if (!PL_rsfp) {
            PL_last_uni = 0;
            PL_last_lop = 0;
-           if (PL_lex_brackets)
-               yyerror("Missing right curly or square bracket");
+           if (PL_lex_brackets) {
+               if (PL_lex_formbrack)
+                   yyerror("Format not terminated");
+                else
+                   yyerror("Missing right curly or square bracket");
+           }
             DEBUG_T( { PerlIO_printf(Perl_debug_log,
                         "### Tokener got EOF\n");
             } );
@@ -2703,7 +2677,9 @@ Perl_yylex(pTHX)
                    else
                        newargv = PL_origargv;
                    newargv[0] = ipath;
+                   PERL_FPU_PRE_EXEC
                    PerlProc_execv(ipath, EXEC_ARGV_CAST(newargv));
+                   PERL_FPU_POST_EXEC
                    Perl_croak(aTHX_ "Can't exec %s", ipath);
                }
 #endif
@@ -2726,6 +2702,14 @@ Perl_yylex(pTHX)
                            }
                            d = moreswitches(d);
                        } while (d);
+                       if (PL_doswitches && !switches_done) {
+                           int argc = PL_origargc;
+                           char **argv = PL_origargv;
+                           do {
+                               argc--,argv++;
+                           } while (argc && argv[0][0] == '-' && argv[0][1]);
+                           init_argv_symbols(argc,argv);
+                       }
                        if ((PERLDB_LINE && !oldpdb) ||
                            ((PL_minus_n || PL_minus_p) && !(oldn || oldp)))
                              /* if we have already added "LINE: while (<>) {",
@@ -2864,10 +2848,10 @@ Perl_yylex(pTHX)
                /* Assume it was a minus followed by a one-letter named
                 * subroutine call (or a -bareword), then. */
                DEBUG_T( { PerlIO_printf(Perl_debug_log,
-                       "### %c looked like a file test but was not\n",
-                       (int)ftst);
+                       "### '-%c' looked like a file test but was not\n",
+                       tmp);
                } );
-               s -= 2;
+               s = --PL_bufptr;
            }
        }
        tmp = *s++;
@@ -2939,8 +2923,6 @@ Perl_yylex(pTHX)
        PL_tokenbuf[0] = '%';
        s = scan_ident(s, PL_bufend, PL_tokenbuf + 1, sizeof PL_tokenbuf - 1, TRUE);
        if (!PL_tokenbuf[1]) {
-           if (s == PL_bufend)
-               yyerror("Final % should be \\% or %name");
            PREREF('%');
        }
        PL_pending_ident = '%';
@@ -3017,19 +2999,27 @@ Perl_yylex(pTHX)
                    PL_lex_stuff = Nullsv;
                }
                else {
+                   if (len == 6 && strnEQ(s, "unique", len)) {
+                       if (PL_in_my == KEY_our)
+#ifdef USE_ITHREADS
+                           GvUNIQUE_on(cGVOPx_gv(yylval.opval));
+#else
+                           ; /* skip to avoid loading attributes.pm */
+#endif
+                       else 
+                           Perl_croak(aTHX_ "The 'unique' attribute may only be applied to 'our' variables");
+                   }
+
                    /* NOTE: any CV attrs applied here need to be part of
                       the CVf_BUILTIN_ATTRS define in cv.h! */
-                   if (!PL_in_my && len == 6 && strnEQ(s, "lvalue", len))
+                   else if (!PL_in_my && len == 6 && strnEQ(s, "lvalue", len))
                        CvLVALUE_on(PL_compcv);
                    else if (!PL_in_my && len == 6 && strnEQ(s, "locked", len))
                        CvLOCKED_on(PL_compcv);
                    else if (!PL_in_my && len == 6 && strnEQ(s, "method", len))
                        CvMETHOD_on(PL_compcv);
-#ifdef USE_ITHREADS
-                   else if (PL_in_my == KEY_our && len == 6 &&
-                            strnEQ(s, "unique", len))
-                       GvUNIQUE_on(cGVOPx_gv(yylval.opval));
-#endif
+                   else if (!PL_in_my && len == 9 && strnEQ(s, "assertion", len))
+                       CvASSERTION_on(PL_compcv);
                    /* After we've set the flags, it could be argued that
                       we don't need to do the attributes.pm-based setting
                       process, and shouldn't bother appending recognized
@@ -3086,6 +3076,7 @@ Perl_yylex(pTHX)
            PL_oldbufptr = PL_oldoldbufptr;             /* allow print(STDOUT 123) */
        else
            PL_expect = XTERM;
+       s = skipspace(s);
        TOKEN('(');
     case ';':
        CLINE;
@@ -3207,12 +3198,17 @@ Perl_yylex(pTHX)
                            || ((*t == 'q' || *t == 'x') && ++t < PL_bufend
                                && !isALNUM(*t))))
                    {
+                       /* skip q//-like construct */
                        char *tmps;
                        char open, close, term;
                        I32 brackets = 1;
 
                        while (t < PL_bufend && isSPACE(*t))
                            t++;
+                       /* check for q => */
+                       if (t+1 < PL_bufend && t[0] == '=' && t[1] == '>') {
+                           OPERATOR(HASHBRACK);
+                       }
                        term = *t;
                        open = term;
                        if (term && (tmps = strchr("([{< )]}> )]}>",term)))
@@ -3225,7 +3221,7 @@ Perl_yylex(pTHX)
                                else if (*t == open)
                                    break;
                            }
-                       else
+                       else {
                            for (t++; t < PL_bufend; t++) {
                                if (*t == '\\' && t+1 < PL_bufend)
                                    t++;
@@ -3234,8 +3230,13 @@ Perl_yylex(pTHX)
                                else if (*t == open)
                                    brackets++;
                            }
+                       }
+                       t++;
                    }
-                   t++;
+                   else
+                       /* skip plain q word */
+                       while (t < PL_bufend && isALNUM_lazy_if(t,UTF))
+                            t += UTF8SKIP(t);
                }
                else if (isALNUM_lazy_if(t,UTF)) {
                    t += UTF8SKIP(t);
@@ -3381,8 +3382,24 @@ Perl_yylex(pTHX)
     case '!':
        s++;
        tmp = *s++;
-       if (tmp == '=')
+       if (tmp == '=') {
+            /* was this !=~ where !~ was meant?
+             * warn on m:!=~\s+([/?]|[msy]\W|tr\W): */
+
+            if (*s == '~' && ckWARN(WARN_SYNTAX)) {
+                char *t = s+1;
+
+                while (t < PL_bufend && isSPACE(*t))
+                    ++t;
+
+                if (*t == '/' || *t == '?' ||
+                    ((*t == 'm' || *t == 's' || *t == 'y') && !isALNUM(t[1])) ||
+                    (*t == 't' && t[1] == 'r' && !isALNUM(t[2])))
+                    Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
+                                "!=~ should be !~");
+            }
            Eop(OP_NE);
+        }
        if (tmp == '~')
            PMop(OP_NOT);
        s--;
@@ -3535,9 +3552,7 @@ Perl_yylex(pTHX)
                    }
                }
                else {
-                   GV *gv = gv_fetchpv(tmpbuf, FALSE, SVt_PVCV);
-                   if (gv && GvCVu(gv))
-                       PL_expect = XTERM;      /* e.g. print $fh subr() */
+                   PL_expect = XTERM;          /* e.g. print $fh subr() */
                }
            }
            else if (isDIGIT(*s))
@@ -3561,8 +3576,6 @@ Perl_yylex(pTHX)
        PL_tokenbuf[0] = '@';
        s = scan_ident(s, PL_bufend, PL_tokenbuf + 1, sizeof PL_tokenbuf - 1, FALSE);
        if (!PL_tokenbuf[1]) {
-           if (s == PL_bufend)
-               yyerror("Final @ should be \\@ or @name");
            PREREF('@');
        }
        if (PL_lex_state == LEX_NORMAL)
@@ -4072,6 +4085,8 @@ Perl_yylex(pTHX)
                            TERM(FUNC0SUB);
                        if (strEQ(proto, "$"))
                            OPERATOR(UNIOPSUB);
+                       while (*proto == ';')
+                           proto++;
                        if (*proto == '&' && *s == '{') {
                            sv_setpv(PL_subname, PL_curstash ? 
                                        "__ANON__" : "__ANON__::__ANON__");
@@ -4186,8 +4201,29 @@ Perl_yylex(pTHX)
                }
 #endif
 #ifdef PERLIO_LAYERS
-               if (UTF && !IN_BYTES)
-                   PerlIO_apply_layers(aTHX_ PL_rsfp, NULL, ":utf8");
+               if (!IN_BYTES) {
+                   if (UTF)
+                       PerlIO_apply_layers(aTHX_ PL_rsfp, NULL, ":utf8");
+                   else if (PL_encoding) {
+                       SV *name;
+                       dSP;
+                       ENTER;
+                       SAVETMPS;
+                       PUSHMARK(sp);
+                       EXTEND(SP, 1);
+                       XPUSHs(PL_encoding);
+                       PUTBACK;
+                       call_method("name", G_SCALAR);
+                       SPAGAIN;
+                       name = POPs;
+                       PUTBACK;
+                       PerlIO_apply_layers(aTHX_ PL_rsfp, NULL, 
+                                           Perl_form(aTHX_ ":encoding(%"SVf")",
+                                                     name));
+                       FREETMPS;
+                       LEAVE;
+                   }
+               }
 #endif
                PL_rsfp = Nullfp;
            }
@@ -5481,7 +5517,9 @@ Perl_keyword(pTHX_ register char *d, I32 len)
            break;
        case 6:
            if (strEQ(d,"exists"))              return KEY_exists;
-           if (strEQ(d,"elseif")) Perl_warn(aTHX_ "elseif should be elsif");
+           if (strEQ(d,"elseif") && ckWARN_d(WARN_SYNTAX))
+               Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
+                       "elseif should be elsif");
            break;
        case 8:
            if (strEQ(d,"endgrent"))            return -KEY_endgrent;
@@ -6274,8 +6312,10 @@ S_scan_ident(pTHX_ register char *s, register char *send, char *dest, STRLEN des
        }
        if (*s == '}') {
            s++;
-           if (PL_lex_state == LEX_INTERPNORMAL && !PL_lex_brackets)
+           if (PL_lex_state == LEX_INTERPNORMAL && !PL_lex_brackets) {
                PL_lex_state = LEX_INTERPEND;
+               PL_expect = XREF;
+           }
            if (funny == '#')
                funny = '@';
            if (PL_lex_state == LEX_NORMAL) {
@@ -6287,8 +6327,6 @@ S_scan_ident(pTHX_ register char *s, register char *send, char *dest, STRLEN des
                        funny, dest, funny, dest);
                }
            }
-           if (PL_lex_inwhat == OP_STRINGIFY)
-               PL_expect = XREF;
        }
        else {
            s = bracket;                /* let the parser handle it */
@@ -6464,7 +6502,8 @@ S_scan_trans(pTHX_ char *start)
 
     New(803, tbl, complement&&!del?258:256, short);
     o = newPVOP(OP_TRANS, 0, (char*)tbl);
-    o->op_private = del|squash|complement|
+    o->op_private &= ~OPpTRANS_ALL;
+    o->op_private |= del|squash|complement|
       (DO_UTF8(PL_lex_stuff)? OPpTRANS_FROM_UTF : 0)|
       (DO_UTF8(PL_lex_repl) ? OPpTRANS_TO_UTF   : 0);
 
@@ -6664,8 +6703,12 @@ retval:
        Renew(SvPVX(tmpstr), SvLEN(tmpstr), char);
     }
     SvREFCNT_dec(herewas);
-    if (UTF && !IN_BYTES && is_utf8_string((U8*)SvPVX(tmpstr), SvCUR(tmpstr)))
-       SvUTF8_on(tmpstr);
+    if (!IN_BYTES) {
+       if (UTF && is_utf8_string((U8*)SvPVX(tmpstr), SvCUR(tmpstr)))
+           SvUTF8_on(tmpstr);
+       else if (PL_encoding)
+           sv_recode_to_utf8(tmpstr, PL_encoding);
+    }
     PL_lex_stuff = tmpstr;
     yylval.ival = op_type;
     return s;
@@ -6949,7 +6992,7 @@ S_scan_str(pTHX_ char *start, int keep_quoted, int keep_delims)
                    goto read_more_line;
                else {
                    /* handle quoted delimiters */
-                   if (*(svlast-1) == '\\') {
+                   if (SvCUR(sv) > 1 && *(svlast-1) == '\\') {
                        char *t;
                        for (t = svlast-2; t >= SvPVX(sv) && *t == '\\';)
                            t--;
@@ -7205,6 +7248,7 @@ Perl_scan_num(pTHX_ char *start, YYSTYPE* lvalp)
            UV u = 0;
            I32 shift;
            bool overflowed = FALSE;
+           bool just_zero  = TRUE;     /* just plain 0 or binary number? */
            static NV nvshift[5] = { 1.0, 2.0, 4.0, 8.0, 16.0 };
            static char* bases[5] = { "", "binary", "", "octal",
                                      "hexadecimal" };
@@ -7221,9 +7265,11 @@ Perl_scan_num(pTHX_ char *start, YYSTYPE* lvalp)
            if (s[1] == 'x') {
                shift = 4;
                s += 2;
+               just_zero = FALSE;
            } else if (s[1] == 'b') {
                shift = 1;
                s += 2;
+               just_zero = FALSE;
            }
            /* check for a decimal in disguise */
            else if (s[1] == '.' || s[1] == 'e' || s[1] == 'E')
@@ -7295,6 +7341,7 @@ Perl_scan_num(pTHX_ char *start, YYSTYPE* lvalp)
                    */
 
                  digit:
+                   just_zero = FALSE;
                    if (!overflowed) {
                        x = u << shift; /* make room for the digit */
 
@@ -7353,7 +7400,10 @@ Perl_scan_num(pTHX_ char *start, YYSTYPE* lvalp)
 #endif
                sv_setuv(sv, u);
            }
-           if (PL_hints & HINT_NEW_BINARY)
+           if (just_zero && (PL_hints & HINT_NEW_INTEGER))
+               sv = new_constant(start, s - start, "integer", 
+                                 sv, Nullsv, NULL);
+           else if (PL_hints & HINT_NEW_BINARY)
                sv = new_constant(start, s - start, "binary", sv, Nullsv, NULL);
        }
        break;
@@ -7549,20 +7599,23 @@ S_scan_formline(pTHX_ register char *s)
     register char *t;
     SV *stuff = newSVpvn("",0);
     bool needargs = FALSE;
+    bool eofmt = FALSE;
 
     while (!needargs) {
-       if (*s == '.' || *s == /*{*/'}') {
+       if (*s == '.') {
            /*SUPPRESS 530*/
 #ifdef PERL_STRICT_CR
            for (t = s+1;SPACE_OR_TAB(*t); t++) ;
 #else
            for (t = s+1;SPACE_OR_TAB(*t) || *t == '\r'; t++) ;
 #endif
-           if (*t == '\n' || t == PL_bufend)
+           if (*t == '\n' || t == PL_bufend) {
+               eofmt = TRUE;
                break;
+            }
        }
        if (PL_in_eval && !PL_rsfp) {
-           eol = strchr(s,'\n');
+           eol = memchr(s,'\n',PL_bufend-s);
            if (!eol++)
                eol = PL_bufend;
        }
@@ -7599,7 +7652,6 @@ S_scan_formline(pTHX_ register char *s)
            PL_last_lop = PL_last_uni = Nullch;
            if (!s) {
                s = PL_bufptr;
-               yyerror("Format not terminated");
                break;
            }
        }
@@ -7615,6 +7667,12 @@ S_scan_formline(pTHX_ register char *s)
        }
        else
            PL_lex_state = LEX_FORMLINE;
+       if (!IN_BYTES) {
+           if (UTF && is_utf8_string((U8*)SvPVX(stuff), SvCUR(stuff)))
+               SvUTF8_on(stuff);
+           else if (PL_encoding)
+               sv_recode_to_utf8(stuff, PL_encoding);
+       }
        PL_nextval[PL_nexttoke].opval = (OP*)newSVOP(OP_CONST, 0, stuff);
        force_next(THING);
        PL_nextval[PL_nexttoke].ival = OP_FORMLINE;
@@ -7622,7 +7680,8 @@ S_scan_formline(pTHX_ register char *s)
     }
     else {
        SvREFCNT_dec(stuff);
-       PL_lex_formbrack = 0;
+       if (eofmt)
+           PL_lex_formbrack = 0;
        PL_bufptr = s;
     }
     return s;
@@ -7718,12 +7777,7 @@ Perl_yyerror(pTHX_ char *s)
     }
     else if (yychar > 255)
        where = "next token ???";
-#ifdef USE_PURE_BISON
-/*  GNU Bison sets the value -2 */
-    else if (yychar == -2) {
-#else
-    else if ((yychar & 127) == 127) {
-#endif
+    else if (yychar == -2) { /* YYEMPTY */
        if (PL_lex_state == LEX_NORMAL ||
           (PL_lex_state == LEX_KNOWNEXT && PL_lex_defer == LEX_NORMAL))
            where = "at end of line";
@@ -7755,8 +7809,8 @@ Perl_yyerror(pTHX_ char *s)
                 (int)PL_multi_open,(int)PL_multi_close,(IV)PL_multi_start);
         PL_multi_end = 0;
     }
-    if (PL_in_eval & EVAL_WARNONLY)
-       Perl_warn(aTHX_ "%"SVf, msg);
+    if (PL_in_eval & EVAL_WARNONLY && ckWARN_d(WARN_SYNTAX))
+       Perl_warner(aTHX_ packWARN(WARN_SYNTAX), "%"SVf, msg);
     else
        qerror(msg);
     if (PL_error_count >= 10) {
@@ -7907,3 +7961,89 @@ utf16rev_textfilter(pTHX_ int idx, SV *sv, int maxlen)
 }
 #endif
 
+/*
+Returns a pointer to the next character after the parsed
+vstring, as well as updating the passed in sv.
+
+Function must be called like
+
+       sv = NEWSV(92,5);
+       s = scan_vstring(s,sv);
+
+The sv should already be large enough to store the vstring
+passed in, for performance reasons.
+
+*/
+
+char *
+Perl_scan_vstring(pTHX_ char *s, SV *sv)
+{
+    char *pos = s;
+    char *start = s;
+    if (*pos == 'v') pos++;  /* get past 'v' */
+    while (pos < PL_bufend && (isDIGIT(*pos) || *pos == '_'))
+       pos++;
+    if ( *pos != '.') {
+       /* this may not be a v-string if followed by => */
+       char *next = pos;
+       while (next < PL_bufend && isSPACE(*next))
+           ++next;
+       if ((PL_bufend - next) >= 2 && *next == '=' && next[1] == '>' ) {
+           /* return string not v-string */
+           sv_setpvn(sv,(char *)s,pos-s);
+           return pos;
+       }
+    }
+
+    if (!isALPHA(*pos)) {
+       UV rev;
+       U8 tmpbuf[UTF8_MAXLEN+1];
+       U8 *tmpend;
+
+       if (*s == 'v') s++;  /* get past 'v' */
+
+       sv_setpvn(sv, "", 0);
+
+       for (;;) {
+           rev = 0;
+           {
+               /* this is atoi() that tolerates underscores */
+               char *end = pos;
+               UV mult = 1;
+               while (--end >= s) {
+                   UV orev;
+                   if (*end == '_')
+                       continue;
+                   orev = rev;
+                   rev += (*end - '0') * mult;
+                   mult *= 10;
+                   if (orev > rev && ckWARN_d(WARN_OVERFLOW))
+                       Perl_warner(aTHX_ packWARN(WARN_OVERFLOW),
+                                   "Integer overflow in decimal number");
+               }
+           }
+#ifdef EBCDIC
+           if (rev > 0x7FFFFFFF)
+                Perl_croak(aTHX_ "In EBCDIC the v-string components cannot exceed 2147483647");
+#endif
+           /* Append native character for the rev point */
+           tmpend = uvchr_to_utf8(tmpbuf, rev);
+           sv_catpvn(sv, (const char*)tmpbuf, tmpend - tmpbuf);
+           if (!UNI_IS_INVARIANT(NATIVE_TO_UNI(rev)))
+                SvUTF8_on(sv);
+           if (pos + 1 < PL_bufend && *pos == '.' && isDIGIT(pos[1]))
+                s = ++pos;
+           else {
+                s = pos;
+                break;
+           }
+           while (pos < PL_bufend && (isDIGIT(*pos) || *pos == '_'))
+                pos++;
+       }
+       SvPOK_on(sv);
+       sv_magic(sv,NULL,PERL_MAGIC_vstring,(const char*)start, pos-start);
+       SvRMAGICAL_on(sv);
+    }
+    return s;
+}
+