Change 29364 forgot to turn the POK flag on.
[p5sagit/p5-mst-13.2.git] / toke.c
diff --git a/toke.c b/toke.c
index b3688bb..d61063a 100644 (file)
--- a/toke.c
+++ b/toke.c
@@ -662,13 +662,11 @@ Perl_lex_start(pTHX_ SV *line)
     PL_lex_inwhat = 0;
     PL_sublex_info.sub_inwhat = 0;
     PL_linestr = line;
-    if (SvREADONLY(PL_linestr))
-       PL_linestr = sv_2mortal(newSVsv(PL_linestr));
     s = SvPV_const(PL_linestr, len);
-    if (!len || s[len-1] != ';') {
-       if (!(SvFLAGS(PL_linestr) & SVs_TEMP))
-           PL_linestr = sv_2mortal(newSVsv(PL_linestr));
-       sv_catpvs(PL_linestr, "\n;");
+    if (SvREADONLY(PL_linestr) || !len || s[len-1] != ';') {
+       PL_linestr = sv_2mortal(len ? newSVsv(PL_linestr) : newSVpvn(s, 0));
+       if (!len || s[len-1] != ';')
+           sv_catpvs(PL_linestr, "\n;");
     }
     SvTEMP_off(PL_linestr);
     PL_oldoldbufptr = PL_oldbufptr = PL_bufptr = PL_linestart = SvPVX(PL_linestr);
@@ -776,12 +774,13 @@ S_incline(pTHX_ char *s)
            gvp = (GV**)hv_fetch(PL_defstash, tmpbuf, tmplen, FALSE);
            if (gvp) {
                gv2 = *(GV**)hv_fetch(PL_defstash, tmpbuf2, tmplen2, TRUE);
-               if (!isGV(gv2))
+               if (!isGV(gv2)) {
                    gv_init(gv2, PL_defstash, tmpbuf2, tmplen2, FALSE);
-               /* adjust ${"::_<newfilename"} to store the new file name */
-               GvSV(gv2) = newSVpvn(tmpbuf2 + 2, tmplen2 - 2);
-               GvHV(gv2) = (HV*)SvREFCNT_inc(GvHV(*gvp));
-               GvAV(gv2) = (AV*)SvREFCNT_inc(GvAV(*gvp));
+                   /* adjust ${"::_<newfilename"} to store the new file name */
+                   GvSV(gv2) = newSVpvn(tmpbuf2 + 2, tmplen2 - 2);
+                   GvHV(gv2) = (HV*)SvREFCNT_inc(GvHV(*gvp));
+                   GvAV(gv2) = (AV*)SvREFCNT_inc(GvAV(*gvp));
+               }
            }
            if (tmpbuf != smallbuf) Safefree(tmpbuf);
            if (tmpbuf2 != smallbuf2) Safefree(tmpbuf2);
@@ -805,7 +804,7 @@ S_skipspace0(pTHX_ register char *s)
        return s;
     if (PL_skipwhite) {
        if (!PL_thiswhite)
-           PL_thiswhite = newSVpvn("",0);
+           PL_thiswhite = newSVpvs("");
        sv_catsv(PL_thiswhite, PL_skipwhite);
        sv_free(PL_skipwhite);
        PL_skipwhite = 0;
@@ -833,7 +832,7 @@ S_skipspace1(pTHX_ register char *s)
     PL_realtokenstart = -1;
     if (PL_skipwhite) {
        if (!PL_nextwhite)
-           PL_nextwhite = newSVpvn("",0);
+           PL_nextwhite = newSVpvs("");
        sv_catsv(PL_nextwhite, PL_skipwhite);
        sv_free(PL_skipwhite);
        PL_skipwhite = 0;
@@ -860,7 +859,7 @@ S_skipspace2(pTHX_ register char *s, SV **svp)
     }
     if (PL_skipwhite) {
        if (!*svp)
-           *svp = newSVpvn("",0);
+           *svp = newSVpvs("");
        sv_setsv(*svp, PL_skipwhite);
        sv_free(PL_skipwhite);
        PL_skipwhite = 0;
@@ -944,7 +943,7 @@ S_skipspace(pTHX_ register char *s)
 #ifdef PERL_MAD
            if (PL_madskills && curoff != startoff) {
                if (!PL_skipwhite)
-                   PL_skipwhite = newSVpvn("",0);
+                   PL_skipwhite = newSVpvs("");
                sv_catpvn(PL_skipwhite, SvPVX(PL_linestr) + startoff,
                                        curoff - startoff);
            }
@@ -1048,7 +1047,7 @@ S_skipspace(pTHX_ register char *s)
   done:
     if (PL_madskills) {
        if (!PL_skipwhite)
-           PL_skipwhite = newSVpvn("",0);
+           PL_skipwhite = newSVpvs("");
        curoff = s - SvPVX(PL_linestr);
        if (curoff - startoff)
            sv_catpvn(PL_skipwhite, SvPVX(PL_linestr) + startoff,
@@ -1159,7 +1158,7 @@ S_start_force(pTHX_ int where)
     PL_curforce = where;
     if (PL_nextwhite) {
        if (PL_madskills)
-           curmad('^', newSVpvn("",0));
+           curmad('^', newSVpvs(""));
        CURMAD('_', PL_nextwhite);
     }
 }
@@ -1275,7 +1274,7 @@ S_force_word(pTHX_ register char *start, int token, int check_keyword, int allow
        (allow_initial_tick && *s == '\'') )
     {
        s = scan_word(s, PL_tokenbuf, sizeof PL_tokenbuf, allow_pack, &len);
-       if (check_keyword && keyword(PL_tokenbuf, len))
+       if (check_keyword && keyword(PL_tokenbuf, len, 0))
            return start;
        start_force(PL_curforce);
        if (PL_madskills)
@@ -1541,6 +1540,14 @@ S_sublex_start(pTHX)
            PL_expect = XTERMORDORDOR;
        return THING;
     }
+    else if (op_type == OP_BACKTICK && PL_lex_op) {
+       /* readpipe() vas overriden */
+       cSVOPx(cLISTOPx(cUNOPx(PL_lex_op)->op_first)->op_first->op_sibling)->op_sv = tokeq(PL_lex_stuff);
+       yylval.opval = PL_lex_op;
+       PL_lex_op = NULL;
+       PL_lex_stuff = NULL;
+       return THING;
+    }
 
     PL_sublex_info.super_state = PL_lex_state;
     PL_sublex_info.sub_inwhat = op_type;
@@ -1674,7 +1681,7 @@ S_sublex_done(pTHX)
        if (PL_madskills) {
            if (PL_thiswhite) {
                if (!PL_endwhite)
-                   PL_endwhite = newSVpvn("",0);
+                   PL_endwhite = newSVpvs("");
                sv_catsv(PL_endwhite, PL_thiswhite);
                PL_thiswhite = 0;
            }
@@ -1790,11 +1797,6 @@ S_scan_const(pTHX_ char *start)
     bool native_range = TRUE; /* turned to FALSE if the first endpoint is Unicode. */
 #endif
 
-    const char * const leaveit = /* set of acceptably-backslashed characters */
-       PL_lex_inpat
-           ? "\\.^$@AGZdDwWsSbBpPXC+*?|()-nrtfeaxcz0123456789[{]} \t\n\r\f\v#"
-           : "";
-
     if (PL_lex_inwhat == OP_TRANS && PL_sublex_info.sub_op) {
        /* If we are doing a trans and we know we want UTF8 set expectation */
        has_utf8   = PL_sublex_info.sub_op->op_private & (OPpTRANS_FROM_UTF|OPpTRANS_TO_UTF);
@@ -2019,13 +2021,6 @@ S_scan_const(pTHX_ char *start)
        if (*s == '\\' && s+1 < send) {
            s++;
 
-           /* some backslashes we leave behind */
-           if (*leaveit && *s && strchr(leaveit, *s)) {
-               *d++ = NATIVE_TO_NEED(has_utf8,'\\');
-               *d++ = NATIVE_TO_NEED(has_utf8,*s++);
-               continue;
-           }
-
            /* deprecate \1 in strings and substitution replacements */
            if (PL_lex_inwhat == OP_SUBST && !PL_lex_inpat &&
                isDIGIT(*s) && *s != '0' && !isDIGIT(s[1]))
@@ -2041,6 +2036,11 @@ S_scan_const(pTHX_ char *start)
                --s;
                break;
            }
+           /* skip any other backslash escapes in a pattern */
+           else if (PL_lex_inpat) {
+               *d++ = NATIVE_TO_NEED(has_utf8,'\\');
+               goto default_action;
+           }
 
            /* if we get here, it's either a quoted -, or a digit */
            switch (*s) {
@@ -2178,6 +2178,7 @@ S_scan_const(pTHX_ char *start)
                    SV *res;
                    STRLEN len;
                    const char *str;
+                   SV *type;
 
                    if (!e) {
                        yyerror("Missing right brace on \\N{}");
@@ -2191,12 +2192,17 @@ S_scan_const(pTHX_ char *start)
                        s += 3;
                        len = e - s;
                        uv = grok_hex(s, &len, &flags, NULL);
+                       if ( e > s && len != (STRLEN)(e - s) ) {
+                           uv = 0xFFFD;
+                       }
                        s = e + 1;
                        goto NUM_ESCAPE_INSERT;
                    }
                    res = newSVpvn(s + 1, e - s - 1);
+                   type = newSVpvn(s - 2,e - s + 3);
                    res = new_constant( NULL, 0, "charnames",
-                                       res, NULL, "\\N{...}" );
+                                       res, NULL, SvPVX(type) );
+                   SvREFCNT_dec(type);         
                    if (has_utf8)
                        sv_utf8_upgrade(res);
                    str = SvPV_const(res,len);
@@ -2352,13 +2358,15 @@ S_scan_const(pTHX_ char *start)
     /* return the substring (via yylval) only if we parsed anything */
     if (s > PL_bufptr) {
        if ( PL_hints & ( PL_lex_inpat ? HINT_NEW_RE : HINT_NEW_STRING ) )
-           sv = new_constant(start, s - start, (PL_lex_inpat ? "qr" : "q"),
+           sv = new_constant(start, s - start,
+                             (const char *)(PL_lex_inpat ? "qr" : "q"),
                              sv, NULL,
-                             ( PL_lex_inwhat == OP_TRANS
-                               ? "tr"
-                               : ( (PL_lex_inwhat == OP_SUBST && !PL_lex_inpat)
-                                   ? "s"
-                                   : "qq")));
+                             (const char *)
+                             (( PL_lex_inwhat == OP_TRANS
+                                ? "tr"
+                                : ( (PL_lex_inwhat == OP_SUBST && !PL_lex_inpat)
+                                    ? "s"
+                                    : "qq"))));
        yylval.opval = (OP*)newSVOP(OP_CONST, 0, sv);
     } else
        SvREFCNT_dec(sv);
@@ -2473,7 +2481,7 @@ S_intuit_more(pTHX_ register char *s)
                if (s[1]) {
                    if (strchr("wds]",s[1]))
                        weight += 100;
-                   else if (seen['\''] || seen['"'])
+                   else if (seen[(U8)'\''] || seen[(U8)'"'])
                        weight += 1;
                    else if (strchr("rnftbxcav",s[1]))
                        weight += 40;
@@ -2505,7 +2513,7 @@ S_intuit_more(pTHX_ register char *s)
                    while (isALPHA(*s))
                        *d++ = *s++;
                    *d = '\0';
-                   if (keyword(tmpbuf, d - tmpbuf))
+                   if (keyword(tmpbuf, d - tmpbuf, 0))
                        weight -= 150;
                }
                if (un_char == last_un_char + 1)
@@ -2584,14 +2592,14 @@ S_intuit_method(pTHX_ char *start, GV *gv, CV *cv)
        len = start - SvPVX(PL_linestr);
 #endif
        s = PEEKSPACE(s);
-#ifdef PERLMAD
+#ifdef PERL_MAD
        start = SvPVX(PL_linestr) + len;
 #endif
        PL_bufptr = start;
        PL_expect = XREF;
        return *s == '(' ? FUNCMETH : METHOD;
     }
-    if (!keyword(tmpbuf, len)) {
+    if (!keyword(tmpbuf, len, 0)) {
        if (len > 2 && tmpbuf[len - 2] == ':' && tmpbuf[len - 1] == ':') {
            len -= 2;
            tmpbuf[len] = '\0';
@@ -2839,6 +2847,34 @@ S_find_in_my_stash(pTHX_ const char *pkgname, I32 len)
     return gv_stashpv(pkgname, FALSE);
 }
 
+/*
+ * S_readpipe_override
+ * Check whether readpipe() is overriden, and generates the appropriate
+ * optree, provided sublex_start() is called afterwards.
+ */
+STATIC void
+S_readpipe_override(pTHX)
+{
+    GV **gvp;
+    GV *gv_readpipe = gv_fetchpvs("readpipe", GV_NOTQUAL, SVt_PVCV);
+    yylval.ival = OP_BACKTICK;
+    if ((gv_readpipe
+               && GvCVu(gv_readpipe) && GvIMPORTED_CV(gv_readpipe))
+           ||
+           ((gvp = (GV**)hv_fetchs(PL_globalstash, "readpipe", FALSE))
+            && (gv_readpipe = *gvp) != (GV*)&PL_sv_undef
+            && GvCVu(gv_readpipe) && GvIMPORTED_CV(gv_readpipe)))
+    {
+       PL_lex_op = (OP*)newUNOP(OP_ENTERSUB, OPf_STACKED,
+           append_elem(OP_LIST,
+               newSVOP(OP_CONST, 0, &PL_sv_undef), /* value will be read later */
+               newCVREF(0, newGVOP(OP_GV, 0, gv_readpipe))));
+    }
+    else {
+       set_csh();
+    }
+}
+
 #ifdef PERL_MAD 
  /*
  * Perl_madlex
@@ -2877,7 +2913,7 @@ Perl_madlex(pTHX)
     if (!PL_thismad || PL_thismad->mad_key == '^') {   /* not forced already? */
        if (!PL_thistoken) {
            if (PL_realtokenstart < 0 || !CopLINE(PL_curcop))
-               PL_thistoken = newSVpvn("",0);
+               PL_thistoken = newSVpvs("");
            else {
                char * const tstart = SvPVX(PL_linestr) + PL_realtokenstart;
                PL_thistoken = newSVpvn(tstart, s - tstart);
@@ -3095,6 +3131,13 @@ Perl_yylex(pTHX)
     STRLEN len;
     bool bof = FALSE;
 
+    /* orig_keyword, gvp, and gv are initialized here because
+     * jump to the label just_a_word_zero can bypass their
+     * initialization later. */
+    I32 orig_keyword = 0;
+    GV *gv = NULL;
+    GV **gvp = NULL;
+
     DEBUG_T( {
        SV* tmp = newSVpvs("");
        PerlIO_printf(Perl_debug_log, "### %"IVdf":LEX_%s/X%s %s\n",
@@ -3176,7 +3219,7 @@ Perl_yylex(pTHX)
                    PL_lex_state = LEX_INTERPCONCAT;
 #ifdef PERL_MAD
                    if (PL_madskills)
-                       PL_thistoken = newSVpvn("\\E",2);
+                       PL_thistoken = newSVpvs("\\E");
 #endif
                }
                return REPORT(')');
@@ -3185,7 +3228,7 @@ Perl_yylex(pTHX)
            while (PL_bufptr != PL_bufend &&
              PL_bufptr[0] == '\\' && PL_bufptr[1] == 'E') {
                if (!PL_thiswhite)
-                   PL_thiswhite = newSVpvn("",0);
+                   PL_thiswhite = newSVpvs("");
                sv_catpvn(PL_thiswhite, PL_bufptr, 2);
                PL_bufptr += 2;
            }
@@ -3203,7 +3246,7 @@ Perl_yylex(pTHX)
            if (s[1] == '\\' && s[2] == 'E') {
 #ifdef PERL_MAD
                if (!PL_thiswhite)
-                   PL_thiswhite = newSVpvn("",0);
+                   PL_thiswhite = newSVpvs("");
                sv_catpvn(PL_thiswhite, PL_bufptr, 4);
 #endif
                PL_bufptr = s + 3;
@@ -3242,7 +3285,7 @@ Perl_yylex(pTHX)
                else
                    Perl_croak(aTHX_ "panic: yylex");
                if (PL_madskills) {
-                   SV* const tmpsv = newSVpvn("",0);
+                   SV* const tmpsv = newSVpvs("");
                    Perl_sv_catpvf(aTHX_ tmpsv, "\\%c", *s);
                    curmad('_', tmpsv);
                }
@@ -3256,7 +3299,7 @@ Perl_yylex(pTHX)
                if (PL_madskills) {
                    if (PL_thistoken)
                        sv_free(PL_thistoken);
-                   PL_thistoken = newSVpvn("",0);
+                   PL_thistoken = newSVpvs("");
                }
 #endif
                /* commas only at base level: /$a\Ub$c/ => ($a,uc(b.$c)) */
@@ -3302,7 +3345,7 @@ Perl_yylex(pTHX)
            if (PL_madskills) {
                if (PL_thistoken)
                    sv_free(PL_thistoken);
-               PL_thistoken = newSVpvn("",0);
+               PL_thistoken = newSVpvs("");
            }
 #endif
            /* commas only at base level: /$a\Ub$c/ => ($a,uc(b.$c)) */
@@ -3328,7 +3371,7 @@ Perl_yylex(pTHX)
            if (PL_madskills) {
                if (PL_thistoken)
                    sv_free(PL_thistoken);
-               PL_thistoken = newSVpvn("",0);
+               PL_thistoken = newSVpvs("");
            }
 #endif
            return REPORT(')');
@@ -3379,7 +3422,7 @@ Perl_yylex(pTHX)
                if (PL_madskills) {
                    if (PL_thistoken)
                        sv_free(PL_thistoken);
-                   PL_thistoken = newSVpvn("",0);
+                   PL_thistoken = newSVpvs("");
                }
 #endif
                /* commas only at base level: /$a\Ub$c/ => ($a,uc(b.$c)) */
@@ -3432,9 +3475,10 @@ Perl_yylex(pTHX)
            PL_last_uni = 0;
            PL_last_lop = 0;
            if (PL_lex_brackets) {
-               yyerror(PL_lex_formbrack
-                   ? "Format not terminated"
-                   : "Missing right curly or square bracket");
+               yyerror((const char *)
+                       (PL_lex_formbrack
+                        ? "Format not terminated"
+                        : "Missing right curly or square bracket"));
            }
             DEBUG_T( { PerlIO_printf(Perl_debug_log,
                         "### Tokener got EOF\n");
@@ -3534,8 +3578,10 @@ Perl_yylex(pTHX)
                    if (PL_madskills)
                        PL_faketokens = 1;
 #endif
-                   sv_setpv(PL_linestr,PL_minus_p
-                            ? ";}continue{print;}" : ";}");
+                   sv_setpv(PL_linestr,
+                            (const char *)
+                            (PL_minus_p
+                             ? ";}continue{print;}" : ";}"));
                    PL_oldoldbufptr = PL_oldbufptr = s = PL_linestart = SvPVX(PL_linestr);
                    PL_bufend = SvPVX(PL_linestr) + SvCUR(PL_linestr);
                    PL_last_lop = PL_last_uni = NULL;
@@ -3879,7 +3925,7 @@ Perl_yylex(pTHX)
                      Perl_croak(aTHX_ "panic: input overflow");
                    if (PL_madskills && CopLINE(PL_curcop) >= 1) {
                        if (!PL_thiswhite)
-                           PL_thiswhite = newSVpvn("",0);
+                           PL_thiswhite = newSVpvs("");
                        if (CopLINE(PL_curcop) == 1) {
                            sv_setpvn(PL_thiswhite, "", 0);
                            PL_faketokens = 0;
@@ -4097,7 +4143,7 @@ Perl_yylex(pTHX)
                I32 tmp;
                SV *sv;
                d = scan_word(s, PL_tokenbuf, sizeof PL_tokenbuf, FALSE, &len);
-               if (isLOWER(*s) && (tmp = keyword(PL_tokenbuf, len))) {
+               if (isLOWER(*s) && (tmp = keyword(PL_tokenbuf, len, 0))) {
                    if (tmp < 0) tmp = -tmp;
                    switch (tmp) {
                    case KEY_or:
@@ -4206,10 +4252,11 @@ Perl_yylex(pTHX)
                       context messages from yyerror().
                    */
                    PL_bufptr = s;
-                   yyerror( *s
-                            ? Perl_form(aTHX_ "Invalid separator character "
-                                        "%c%c%c in attribute list", q, *s, q)
-                            : "Unterminated attribute list" );
+                   yyerror( (const char *)
+                            (*s
+                             ? Perl_form(aTHX_ "Invalid separator character "
+                                         "%c%c%c in attribute list", q, *s, q)
+                             : "Unterminated attribute list" ) );
                    if (attrs)
                        op_free(attrs);
                    OPERATOR(':');
@@ -4446,7 +4493,7 @@ Perl_yylex(pTHX)
 #if 0
                    if (PL_madskills) {
                        if (!PL_thiswhite)
-                           PL_thiswhite = newSVpvn("",0);
+                           PL_thiswhite = newSVpvs("");
                        sv_catpvn(PL_thiswhite,"}",1);
                    }
 #endif
@@ -4471,7 +4518,7 @@ Perl_yylex(pTHX)
        force_next('}');
 #ifdef PERL_MAD
        if (!PL_thistoken)
-           PL_thistoken = newSVpvn("",0);
+           PL_thistoken = newSVpvs("");
 #endif
        TOKEN(';');
     case '&':
@@ -4545,7 +4592,7 @@ Perl_yylex(pTHX)
 #ifdef PERL_MAD
                    if (PL_madskills) {
                        if (!PL_thiswhite)
-                           PL_thiswhite = newSVpvn("",0);
+                           PL_thiswhite = newSVpvs("");
                        sv_catpvn(PL_thiswhite, PL_linestart,
                                  PL_bufend - PL_linestart);
                    }
@@ -4742,7 +4789,7 @@ Perl_yylex(pTHX)
                    char tmpbuf[sizeof PL_tokenbuf];
                    int t2;
                    scan_word(s, tmpbuf, sizeof tmpbuf, TRUE, &len);
-                   if ((t2 = keyword(tmpbuf, len))) {
+                   if ((t2 = keyword(tmpbuf, len, 0))) {
                        /* binary operators exclude handle interpretations */
                        switch (t2) {
                        case -KEY_x:
@@ -4939,8 +4986,7 @@ Perl_yylex(pTHX)
            no_op("Backticks",s);
        if (!s)
            missingterm(NULL);
-       yylval.ival = OP_BACKTICK;
-       set_csh();
+       readpipe_override();
        TERM(sublex_start());
 
     case '\\':
@@ -5015,9 +5061,10 @@ Perl_yylex(pTHX)
 
       keylookup: {
        I32 tmp;
-       I32 orig_keyword = 0;
-       GV *gv = NULL;
-       GV **gvp = NULL;
+
+       orig_keyword = 0;
+       gv = NULL;
+       gvp = NULL;
 
        PL_bufptr = s;
        s = scan_word(s, PL_tokenbuf, sizeof PL_tokenbuf, FALSE, &len);
@@ -5046,7 +5093,7 @@ Perl_yylex(pTHX)
        }
 
        /* Check for keywords */
-       tmp = keyword(PL_tokenbuf, len);
+       tmp = keyword(PL_tokenbuf, len, 0);
 
        /* Is this a word before a => operator? */
        if (*d == '=' && d[1] == '>') {
@@ -5326,7 +5373,7 @@ Perl_yylex(pTHX)
                    if (PL_madskills) {
                        PL_nextwhite = nextPL_nextwhite;
                        curmad('X', PL_thistoken);
-                       PL_thistoken = newSVpvn("",0);
+                       PL_thistoken = newSVpvs("");
                    }
 #endif
                    force_next(WORD);
@@ -5384,18 +5431,21 @@ Perl_yylex(pTHX)
 #ifdef PERL_MAD
                        cv &&
 #endif
-                       SvPOK(cv)) {
+                       SvPOK(cv))
+                   {
                        STRLEN protolen;
                        const char *proto = SvPV_const((SV*)cv, protolen);
                        if (!protolen)
                            TERM(FUNC0SUB);
-                       if (*proto == '$' && proto[1] == '\0')
+                       if ((*proto == '$' || *proto == '_') && proto[1] == '\0')
                            OPERATOR(UNIOPSUB);
                        while (*proto == ';')
                            proto++;
                        if (*proto == '&' && *s == '{') {
-                           sv_setpv(PL_subname, PL_curstash ?
-                                       "__ANON__" : "__ANON__::__ANON__");
+                           sv_setpv(PL_subname,
+                                    (const char *)
+                                    (PL_curstash ?
+                                     "__ANON__" : "__ANON__::__ANON__"));
                            PREBLOCK(LSTOPSUB);
                        }
                    }
@@ -5411,7 +5461,7 @@ Perl_yylex(pTHX)
                        if (PL_madskills) {
                            PL_nextwhite = nextPL_nextwhite;
                            curmad('X', PL_thistoken);
-                           PL_thistoken = newSVpvn("",0);
+                           PL_thistoken = newSVpvs("");
                        }
                        force_next(WORD);
                        TOKEN(NOAMP);
@@ -5428,7 +5478,7 @@ Perl_yylex(pTHX)
                        STRLEN tmplen;
                        d = s;
                        d = scan_word(d, tmpbuf, sizeof tmpbuf, TRUE, &tmplen);
-                       if (!keyword(tmpbuf,tmplen))
+                       if (!keyword(tmpbuf, tmplen, 0))
                            probable_sub = 1;
                        else {
                            while (d < PL_bufend && isSPACE(*d))
@@ -5451,7 +5501,7 @@ Perl_yylex(pTHX)
                        PL_expect = XTERM;
                        PL_nextwhite = nextPL_nextwhite;
                        curmad('X', PL_thistoken);
-                       PL_thistoken = newSVpvn("",0);
+                       PL_thistoken = newSVpvs("");
                        force_next(WORD);
                        TOKEN(NOAMP);
                    }
@@ -5596,7 +5646,7 @@ Perl_yylex(pTHX)
                    if (PL_realtokenstart >= 0) {
                        char *tstart = SvPVX(PL_linestr) + PL_realtokenstart;
                        if (!PL_endwhite)
-                           PL_endwhite = newSVpvn("",0);
+                           PL_endwhite = newSVpvs("");
                        sv_catsv(PL_endwhite, PL_thiswhite);
                        PL_thiswhite = 0;
                        sv_catpvn(PL_endwhite, tstart, PL_bufend - tstart);
@@ -5614,6 +5664,7 @@ Perl_yylex(pTHX)
        case KEY_AUTOLOAD:
        case KEY_DESTROY:
        case KEY_BEGIN:
+       case KEY_UNITCHECK:
        case KEY_CHECK:
        case KEY_INIT:
        case KEY_END:
@@ -5628,7 +5679,7 @@ Perl_yylex(pTHX)
                s += 2;
                d = s;
                s = scan_word(s, PL_tokenbuf, sizeof PL_tokenbuf, FALSE, &len);
-               if (!(tmp = keyword(PL_tokenbuf, len)))
+               if (!(tmp = keyword(PL_tokenbuf, len, 0)))
                    Perl_croak(aTHX_ "CORE::%s is not a keyword", PL_tokenbuf);
                if (tmp < 0)
                    tmp = -tmp;
@@ -6254,8 +6305,7 @@ Perl_yylex(pTHX)
            s = scan_str(s,!!PL_madskills,FALSE);
            if (!s)
                missingterm(NULL);
-           yylval.ival = OP_BACKTICK;
-           set_csh();
+           readpipe_override();
            TERM(sublex_start());
 
        case KEY_return:
@@ -6472,7 +6522,7 @@ Perl_yylex(pTHX)
                char tmpbuf[sizeof PL_tokenbuf];
                SSize_t tboffset = 0;
                expectation attrful;
-               bool have_name, have_proto, bad_proto;
+               bool have_name, have_proto;
                const int key = tmp;
 
 #ifdef PERL_MAD
@@ -6552,6 +6602,8 @@ Perl_yylex(pTHX)
                /* Look for a prototype */
                if (*s == '(') {
                    char *p;
+                   bool bad_proto = FALSE;
+                   const bool warnsyntax = ckWARN(WARN_SYNTAX);
 
                    s = scan_str(s,!!PL_madskills,FALSE);
                    if (!s)
@@ -6559,16 +6611,15 @@ Perl_yylex(pTHX)
                    /* strip spaces and check for bad characters */
                    d = SvPVX(PL_lex_stuff);
                    tmp = 0;
-                   bad_proto = FALSE;
                    for (p = d; *p; ++p) {
                        if (!isSPACE(*p)) {
                            d[tmp++] = *p;
-                           if (!strchr("$@%*;[]&\\", *p))
+                           if (warnsyntax && !strchr("$@%*;[]&\\_", *p))
                                bad_proto = TRUE;
                        }
                    }
                    d[tmp] = '\0';
-                   if (bad_proto && ckWARN(WARN_SYNTAX))
+                   if (bad_proto)
                        Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
                                    "Illegal character in prototype for %"SVf" : %s",
                                    (void*)PL_subname, d);
@@ -6607,7 +6658,7 @@ Perl_yylex(pTHX)
                start_force(0);
                if (tmpwhite) {
                    if (PL_madskills)
-                       curmad('^', newSVpvn("",0));
+                       curmad('^', newSVpvs(""));
                    CURMAD('_', tmpwhite);
                }
                force_next(0);
@@ -6623,7 +6674,8 @@ Perl_yylex(pTHX)
 #endif
                if (!have_name) {
                    sv_setpv(PL_subname,
-                       PL_curstash ? "__ANON__" : "__ANON__::__ANON__");
+                            (const char *)
+                            (PL_curstash ? "__ANON__" : "__ANON__::__ANON__"));
                    TOKEN(ANONSUB);
                }
 #ifndef PERL_MAD
@@ -6929,7 +6981,7 @@ S_pending_ident(pTHX)
  */
 
 I32
-Perl_keyword (pTHX_ const char *name, I32 len)
+Perl_keyword (pTHX_ const char *name, I32 len, bool all_keywords)
 {
     dVAR;
   switch (len)
@@ -7201,7 +7253,7 @@ Perl_keyword (pTHX_ const char *name, I32 len)
             case 'r':
               if (name[2] == 'r')
               {                                   /* err        */
-                return (FEATURE_IS_ENABLED("err") ? -KEY_err : 0);
+                return (all_keywords || FEATURE_IS_ENABLED("err") ? -KEY_err : 0);
               }
 
               goto unknown;
@@ -7340,7 +7392,7 @@ Perl_keyword (pTHX_ const char *name, I32 len)
             case 'a':
               if (name[2] == 'y')
               {                                   /* say        */
-                return (FEATURE_IS_ENABLED("say") ? -KEY_say : 0);
+                return (all_keywords || FEATURE_IS_ENABLED("say") ? KEY_say : 0);
               }
 
               goto unknown;
@@ -7864,7 +7916,7 @@ Perl_keyword (pTHX_ const char *name, I32 len)
               if (name[2] == 'e' &&
                   name[3] == 'n')
               {                                   /* when       */
-                return (FEATURE_IS_ENABLED("switch") ? KEY_when : 0);
+                return (all_keywords || FEATURE_IS_ENABLED("switch") ? KEY_when : 0);
               }
 
               goto unknown;
@@ -7947,7 +7999,7 @@ Perl_keyword (pTHX_ const char *name, I32 len)
                   name[3] == 'a' &&
                   name[4] == 'k')
               {                                   /* break      */
-                return (FEATURE_IS_ENABLED("switch") ? -KEY_break : 0);
+                return (all_keywords || FEATURE_IS_ENABLED("switch") ? -KEY_break : 0);
               }
 
               goto unknown;
@@ -8075,7 +8127,7 @@ Perl_keyword (pTHX_ const char *name, I32 len)
               name[3] == 'e' &&
               name[4] == 'n')
           {                                       /* given      */
-            return (FEATURE_IS_ENABLED("switch") ? KEY_given : 0);
+            return (all_keywords || FEATURE_IS_ENABLED("switch") ? KEY_given : 0);
           }
 
           goto unknown;
@@ -8243,7 +8295,7 @@ Perl_keyword (pTHX_ const char *name, I32 len)
                   if (name[3] == 't' &&
                       name[4] == 'e')
                   {                               /* state      */
-                    return (FEATURE_IS_ENABLED("state") ? KEY_state : 0);
+                    return (all_keywords || FEATURE_IS_ENABLED("state") ? KEY_state : 0);
                   }
 
                   goto unknown;
@@ -8911,7 +8963,7 @@ Perl_keyword (pTHX_ const char *name, I32 len)
                         name[5] == 'l' &&
                         name[6] == 't')
                     {                             /* default    */
-                      return (FEATURE_IS_ENABLED("switch") ? KEY_default : 0);
+                      return (all_keywords || FEATURE_IS_ENABLED("switch") ? KEY_default : 0);
                     }
 
                     goto unknown;
@@ -9665,9 +9717,24 @@ Perl_keyword (pTHX_ const char *name, I32 len)
           goto unknown;
       }
 
-    case 9: /* 8 tokens of length 9 */
+    case 9: /* 9 tokens of length 9 */
       switch (name[0])
       {
+        case 'U':
+          if (name[1] == 'N' &&
+              name[2] == 'I' &&
+              name[3] == 'T' &&
+              name[4] == 'C' &&
+              name[5] == 'H' &&
+              name[6] == 'E' &&
+              name[7] == 'C' &&
+              name[8] == 'K')
+          {                                       /* UNITCHECK  */
+            return KEY_UNITCHECK;
+          }
+
+          goto unknown;
+
         case 'e':
           if (name[1] == 'n' &&
               name[2] == 'd' &&
@@ -10344,7 +10411,7 @@ S_checkcomma(pTHX_ const char *s, const char *name, const char *what)
            s++;
        if (*s == ',') {
            GV* gv;
-           if (keyword(w, s - w))
+           if (keyword(w, s - w, 0))
                return;
 
            gv = gv_fetchpvn_flags(w, s - w, 0, SVt_PVCV);
@@ -10374,9 +10441,10 @@ S_new_constant(pTHX_ const char *s, STRLEN len, const char *key, SV *sv, SV *pv,
     if (!table || !(PL_hints & HINT_LOCALIZE_HH)) {
        SV *msg;
        
-       why2 = strEQ(key,"charnames")
-              ? "(possibly a missing \"use charnames ...\")"
-              : "";
+       why2 = (const char *)
+           (strEQ(key,"charnames")
+            ? "(possibly a missing \"use charnames ...\")"
+            : "");
        msg = Perl_newSVpvf(aTHX_ "Constant(%s) unknown: %s",
                            (type ? type: "undef"), why2);
 
@@ -10603,8 +10671,10 @@ S_scan_ident(pTHX_ register char *s, register const char *send, char *dest, STRL
            while (s < send && SPACE_OR_TAB(*s))
                s++;
            if ((*s == '[' || (*s == '{' && strNE(dest, "sub")))) {
-               if (ckWARN(WARN_AMBIGUOUS) && keyword(dest, d - dest)) {
-                   const char * const brack = (*s == '[') ? "[...]" : "{...}";
+               if (ckWARN(WARN_AMBIGUOUS) && keyword(dest, d - dest, 0)) {
+                   const char * const brack =
+                       (const char *)
+                       ((*s == '[') ? "[...]" : "{...}");
                    Perl_warner(aTHX_ packWARN(WARN_AMBIGUOUS),
                        "Ambiguous use of %c{%s%s} resolved to %c%s%s",
                        funny, dest, brack, funny, dest, brack);
@@ -10635,7 +10705,7 @@ S_scan_ident(pTHX_ register char *s, register const char *send, char *dest, STRL
            }
            if (PL_lex_state == LEX_NORMAL) {
                if (ckWARN(WARN_AMBIGUOUS) &&
-                   (keyword(dest, d - dest) || get_cv(dest, FALSE)))
+                   (keyword(dest, d - dest, 0) || get_cv(dest, FALSE)))
                {
                    if (funny == '#')
                        funny = '@';
@@ -10681,7 +10751,8 @@ S_scan_pat(pTHX_ char *start, I32 type)
     dVAR;
     PMOP *pm;
     char *s = scan_str(start,!!PL_madskills,FALSE);
-    const char * const valid_flags = (type == OP_QR) ? "iomsx" : "iogcmsx";
+    const char * const valid_flags =
+       (const char *)((type == OP_QR) ? "iomsx" : "iogcmsx");
 #ifdef PERL_MAD
     char *modstart;
 #endif
@@ -10689,9 +10760,11 @@ S_scan_pat(pTHX_ char *start, I32 type)
 
     if (!s) {
        const char * const delimiter = skipspace(start);
-       Perl_croak(aTHX_ *delimiter == '?'
-                  ? "Search pattern not terminated or ternary operator parsed as search pattern"
-                  : "Search pattern not terminated" );
+       Perl_croak(aTHX_
+                  (const char *)
+                  (*delimiter == '?'
+                   ? "Search pattern not terminated or ternary operator parsed as search pattern"
+                   : "Search pattern not terminated" ));
     }
 
     pm = (PMOP*)newPMOP(type, 0);
@@ -10806,7 +10879,7 @@ S_scan_subst(pTHX_ char *start)
        PL_multi_end = 0;
        pm->op_pmflags |= PMf_EVAL;
        while (es-- > 0)
-           sv_catpv(repl, es ? "eval " : "do ");
+           sv_catpv(repl, (const char *)(es ? "eval " : "do "));
        sv_catpvs(repl, "{");
        sv_catsv(repl, PL_lex_repl);
        if (strchr(SvPVX(PL_lex_repl), '#'))
@@ -11004,7 +11077,7 @@ S_scan_heredoc(pTHX_ register char *s)
 #ifdef PERL_MAD
     found_newline = 0;
 #endif
-    if ( outer || !(found_newline = memchr(s, '\n', PL_bufend - s)) ) {
+    if ( outer || !(found_newline = (char*)memchr((void*)s, '\n', PL_bufend - s)) ) {
         herewas = newSVpvn(s,PL_bufend-s);
     }
     else {
@@ -11390,7 +11463,7 @@ S_scan_str(pTHX_ char *start, int keep_quoted, int keep_delims)
 {
     dVAR;
     SV *sv;                            /* scalar value: string */
-    char *tmps;                                /* temp string, used for delimiter matching */
+    const char *tmps;                  /* temp string, used for delimiter matching */
     register char *s = start;          /* current position in the buffer */
     register char term;                        /* terminating character */
     register char *to;                 /* current position in the sv's data */
@@ -11399,7 +11472,7 @@ S_scan_str(pTHX_ char *start, int keep_quoted, int keep_delims)
     I32 termcode;                      /* terminating char. code */
     U8 termstr[UTF8_MAXBYTES];         /* terminating string */
     STRLEN termlen;                    /* length of terminating string */
-    char *last = NULL;                 /* last position for nesting bracket */
+    int last_off = 0;                  /* last position for nesting bracket */
 #ifdef PERL_MAD
     int stuffstart;
     char *tstart;
@@ -11500,9 +11573,7 @@ S_scan_str(pTHX_ char *start, int keep_quoted, int keep_delims)
                    else {
                        const char *t;
                        char *w;
-                       if (!last)
-                           last = SvPVX(sv);
-                       for (t = w = last; t < svlast; w++, t++) {
+                       for (t = w = SvPVX(sv)+last_off; t < svlast; w++, t++) {
                            /* At here, all closes are "was quoted" one,
                               so we don't check PL_multi_close. */
                            if (*t == '\\') {
@@ -11521,7 +11592,7 @@ S_scan_str(pTHX_ char *start, int keep_quoted, int keep_delims)
                            *w = '\0';
                            SvCUR_set(sv, w - SvPVX_const(sv));
                        }
-                       last = w;
+                       last_off = w - SvPVX(sv);
                        if (--brackets <= 0)
                            cont = FALSE;
                    }
@@ -12100,7 +12171,9 @@ Perl_scan_num(pTHX_ const char *start, YYSTYPE* lvalp)
 
        if ( floatit ? (PL_hints & HINT_NEW_FLOAT) :
                       (PL_hints & HINT_NEW_INTEGER) )
-           sv = new_constant(PL_tokenbuf, d - PL_tokenbuf,
+           sv = new_constant(PL_tokenbuf,
+                             d - PL_tokenbuf,
+                             (const char *)
                              (floatit ? "float" : "integer"),
                              sv, NULL, NULL);
        break;