This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
perlcc.PL cleanups
[perl5.git] / toke.c
diff --git a/toke.c b/toke.c
index e47853e..6cb8e16 100644 (file)
--- a/toke.c
+++ b/toke.c
 static char ident_too_long[] = "Identifier too long";
 
 static void restore_rsfp(pTHXo_ void *f);
+#ifndef PERL_NO_UTF16_FILTER
+static I32 utf16_textfilter(pTHXo_ int idx, SV *sv, int maxlen);
+static I32 utf16rev_textfilter(pTHXo_ int idx, SV *sv, int maxlen);
+#endif
 
 #define XFAKEBRACK 128
 #define XENUMMASK 127
@@ -65,26 +69,24 @@ static void restore_rsfp(pTHXo_ void *f);
 #define LEX_FORMLINE            1
 #define LEX_KNOWNEXT            0
 
-/* XXX If this causes problems, set i_unistd=undef in the hint file.  */
-#ifdef I_UNISTD
-#  include <unistd.h> /* Needed for execv() */
-#endif
-
-
 #ifdef ff_next
 #undef ff_next
 #endif
 
 #ifdef USE_PURE_BISON
-YYSTYPE* yylval_pointer = NULL;
-int* yychar_pointer = NULL;
+#  ifndef YYMAXLEVEL
+#    define YYMAXLEVEL 100
+#  endif
+YYSTYPE* yylval_pointer[YYMAXLEVEL];
+int* yychar_pointer[YYMAXLEVEL];
+int yyactlevel = 0;
 #  undef yylval
 #  undef yychar
-#  define yylval (*yylval_pointer)
-#  define yychar (*yychar_pointer)
-#  define PERL_YYLEX_PARAM yylval_pointer,yychar_pointer
-#  undef yylex
-#  define yylex()      Perl_yylex(aTHX_ yylval_pointer, yychar_pointer)
+#  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"
@@ -205,10 +207,8 @@ S_no_op(pTHX_ char *what, char *s)
 
     if (!s)
        s = oldbp;
-    else {
-       assert(s >= oldbp);
+    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");
@@ -219,8 +219,10 @@ S_no_op(pTHX_ char *what, char *s)
            Perl_warn(aTHX_ "\t(Do you need to predeclare %.*s?)\n",
                t - PL_oldoldbufptr, PL_oldoldbufptr);
     }
-    else
+    else {
+       assert(s >= oldbp);
        Perl_warn(aTHX_ "\t(Missing operator before %.*s?)\n", s - oldbp, oldbp);
+    }
     PL_bufptr = oldbp;
 }
 
@@ -326,36 +328,6 @@ S_cr_textfilter(pTHX_ int idx, SV *sv, int maxlen)
 }
 #endif
 
-#ifndef PERL_NO_UTF16_FILTER
-STATIC I32
-S_utf16_textfilter(pTHX_ int idx, SV *sv, int maxlen)
-{
-    I32 count = FILTER_READ(idx+1, sv, maxlen);
-    if (count) {
-       U8* tmps;
-       U8* tend;
-       New(898, tmps, SvCUR(sv) * 3 / 2 + 1, U8);
-       tend = utf16_to_utf8((U16*)SvPVX(sv), tmps, SvCUR(sv));
-       sv_usepvn(sv, (char*)tmps, tend - tmps);
-    }
-    return count;
-}
-
-STATIC I32
-S_utf16rev_textfilter(pTHX_ int idx, SV *sv, int maxlen)
-{
-    I32 count = FILTER_READ(idx+1, sv, maxlen);
-    if (count) {
-       U8* tmps;
-       U8* tend;
-       New(898, tmps, SvCUR(sv) * 3 / 2 + 1, U8);
-       tend = utf16_to_utf8_reversed((U16*)SvPVX(sv), tmps, SvCUR(sv));
-       sv_usepvn(sv, (char*)tmps, tend - tmps);
-    }
-    return count;
-}
-#endif
-
 /*
  * Perl_lex_start
  * Initialize variables.  Uses the Perl save_stack to save its state (for
@@ -383,7 +355,6 @@ Perl_lex_start(pTHX_ SV *line)
            SAVEVPTR(PL_nextval[toke]);
        }
        SAVEI32(PL_nexttoke);
-       PL_nexttoke = 0;
     }
     SAVECOPLINE(PL_curcop);
     SAVEPPTR(PL_bufptr);
@@ -417,6 +388,7 @@ Perl_lex_start(pTHX_ SV *line)
     PL_lex_stuff = Nullsv;
     PL_lex_repl = Nullsv;
     PL_lex_inpat = 0;
+    PL_nexttoke = 0;
     PL_lex_inwhat = 0;
     PL_sublex_info.sub_inwhat = 0;
     PL_linestr = line;
@@ -835,10 +807,10 @@ Perl_str_to_version(pTHX_ SV *sv)
     bool utf = SvUTF8(sv) ? TRUE : FALSE;
     char *end = start + len;
     while (start < end) {
-       I32 skip;
+       STRLEN skip;
        UV n;
        if (utf)
-           n = utf8_to_uv((U8*)start, &skip);
+           n = utf8_to_uv((U8*)start, len, &skip, 0);
        else {
            n = *(U8*)start;
            skip = 1;
@@ -870,7 +842,7 @@ S_force_version(pTHX_ char *s)
         for (; isDIGIT(*d) || *d == '_' || *d == '.'; d++);
         if (*d == ';' || isSPACE(*d) || *d == '}' || !*d) {
            SV *ver;
-            s = scan_num(s);
+            s = scan_num(s, &yylval);
             version = yylval.opval;
            ver = cSVOPx(version)->op_sv;
            if (SvPOK(ver) && !SvNIOK(ver)) {
@@ -1209,14 +1181,13 @@ S_scan_const(pTHX_ char *start)
     register char *d = SvPVX(sv);              /* destination for copies */
     bool dorange = FALSE;                      /* are we in a translit range? */
     bool didrange = FALSE;                     /* did we just finish a range? */
-    bool has_utf = FALSE;                      /* embedded \x{} */
-    I32 len;                                   /* ? */
+    bool has_utf8 = FALSE;                     /* embedded \x{} */
     UV uv;
 
     I32 utf = (PL_lex_inwhat == OP_TRANS && PL_sublex_info.sub_op)
        ? (PL_sublex_info.sub_op->op_private & (OPpTRANS_FROM_UTF|OPpTRANS_TO_UTF))
        : UTF;
-    I32 thisutf = (PL_lex_inwhat == OP_TRANS && PL_sublex_info.sub_op)
+    I32 this_utf8 = (PL_lex_inwhat == OP_TRANS && PL_sublex_info.sub_op)
        ? (PL_sublex_info.sub_op->op_private & (PL_lex_repl ?
                                                OPpTRANS_FROM_UTF : OPpTRANS_TO_UTF))
        : UTF;
@@ -1245,7 +1216,7 @@ S_scan_const(pTHX_ char *start)
                 if (min > max) {
                    Perl_croak(aTHX_
                               "Invalid [] range \"%c-%c\" in transliteration operator",
-                              min, max);
+                              (char)min, (char)max);
                 }
 
 #ifndef ASCIIish
@@ -1331,9 +1302,11 @@ S_scan_const(pTHX_ char *start)
                *d++ = *s++;
        }
 
-       /* check for embedded arrays (@foo, @:foo, @'foo, @{foo}, @$foo) */
+       /* check for embedded arrays
+          (@foo, @:foo, @'foo, @{foo}, @$foo, @+, @-)
+          */
        else if (*s == '@' && s[1]
-                && (isALNUM_lazy_if(s+1,UTF) || strchr(":'{$", s[1])))
+                && (isALNUM_lazy_if(s+1,UTF) || strchr(":'{$+-", s[1])))
            break;
 
        /* check for embedded scalars.  only stop if we're sure it's a
@@ -1348,21 +1321,24 @@ S_scan_const(pTHX_ char *start)
 
        /* (now in tr/// code again) */
 
-       if (*s & 0x80 && thisutf) {
-          (void)utf8_to_uv((U8*)s, &len);
-          if (len == 1) {
-              /* illegal UTF8, make it valid */
-              char *old_pvx = SvPVX(sv);
-              /* need space for one extra char (NOTE: SvCUR() not set here) */
-              d = SvGROW(sv, SvLEN(sv) + 1) + (d - old_pvx);
-              d = (char*)uv_to_utf8((U8*)d, (U8)*s++);
-          }
-          else {
-              while (len--)
-                  *d++ = *s++;
-          }
-          has_utf = TRUE;
-          continue;
+       if (*s & 0x80 && this_utf8) {
+           STRLEN len;
+           UV uv;
+
+           uv = utf8_to_uv((U8*)s, send - s, &len, UTF8_CHECK_ONLY);
+           if (len == (STRLEN)-1) {
+               /* Illegal UTF8 (a high-bit byte), make it valid. */
+               char *old_pvx = SvPVX(sv);
+               /* need space for one extra char (NOTE: SvCUR() not set here) */
+               d = SvGROW(sv, SvLEN(sv) + 1) + (d - old_pvx);
+               d = (char*)uv_to_utf8((U8*)d, (U8)*s++);
+           }
+           else {
+               while (len--)
+                   *d++ = *s++;
+           }
+           has_utf8 = TRUE;
+           continue;
        }
 
        /* backslashes */
@@ -1418,9 +1394,11 @@ S_scan_const(pTHX_ char *start)
            /* \132 indicates an octal constant */
            case '0': case '1': case '2': case '3':
            case '4': case '5': case '6': case '7':
-               len = 0;        /* disallow underscores */
-               uv = (UV)scan_oct(s, 3, &len);
-               s += len;
+               {
+                   STRLEN len = 0;     /* disallow underscores */
+                   uv = (UV)scan_oct(s, 3, &len);
+                   s += len;
+               }
                goto NUM_ESCAPE_INSERT;
 
            /* \x24 indicates a hex constant */
@@ -1432,14 +1410,19 @@ S_scan_const(pTHX_ char *start)
                        yyerror("Missing right brace on \\x{}");
                        e = s;
                    }
-                   len = 1;            /* allow underscores */
-                    uv = (UV)scan_hex(s + 1, e - s - 1, &len);
-                    s = e + 1;
+                   else {
+                       STRLEN len = 1;         /* allow underscores */
+                       uv = (UV)scan_hex(s + 1, e - s - 1, &len);
+                       has_utf8 = TRUE;
+                   }
+                   s = e + 1;
                }
                else {
-                   len = 0;            /* disallow underscores */
-                   uv = (UV)scan_hex(s, 2, &len);
-                   s += len;
+                   {
+                       STRLEN len = 0;         /* disallow underscores */
+                       uv = (UV)scan_hex(s, 2, &len);
+                       s += len;
+                   }
                }
 
              NUM_ESCAPE_INSERT:
@@ -1447,8 +1430,8 @@ S_scan_const(pTHX_ char *start)
                 * There will always enough room in sv since such escapes will
                 * be longer than any utf8 sequence they can end up as
                 */
-               if (uv > 127) {
-                   if (!thisutf && !has_utf && uv > 255) {
+               if (uv > 127 || has_utf8) {
+                   if (!this_utf8 && !has_utf8 && uv > 255) {
                        /* might need to recode whatever we have accumulated so far
                         * if it contains any hibit chars
                         */
@@ -1480,9 +1463,9 @@ S_scan_const(pTHX_ char *start)
                         }
                     }
 
-                    if (thisutf || uv > 255) {
+                    if (has_utf8 || uv > 255) {
                        d = (char*)uv_to_utf8((U8*)d, uv);
-                       has_utf = TRUE;
+                       this_utf8 = TRUE;
                     }
                    else {
                        *d++ = (char)uv;
@@ -1511,13 +1494,16 @@ S_scan_const(pTHX_ char *start)
                    res = new_constant( Nullch, 0, "charnames", 
                                        res, Nullsv, "\\N{...}" );
                    str = SvPV(res,len);
-                   if (!has_utf && SvUTF8(res)) {
+                   if (!has_utf8 && SvUTF8(res)) {
                        char *ostart = SvPVX(sv);
                        SvCUR_set(sv, d - ostart);
                        SvPOK_on(sv);
+                       *d = '\0';
                        sv_utf8_upgrade(sv);
+                       /* this just broke our allocation above... */
+                       SvGROW(sv, send - start);
                        d = SvPVX(sv) + SvCUR(sv);
-                       has_utf = TRUE;
+                       has_utf8 = TRUE;
                    }
                    if (len > e - s + 4) {
                        char *odest = SvPVX(sv);
@@ -1545,8 +1531,10 @@ S_scan_const(pTHX_ char *start)
                *d = toCTRL(*d); 
                d++;
 #else
-               len = *s++;
-               *d++ = toCTRL(len);
+               {
+                   U8 c = *s++;
+                   *d++ = toCTRL(c);
+               }
 #endif
                continue;
 
@@ -1594,7 +1582,7 @@ S_scan_const(pTHX_ char *start)
     *d = '\0';
     SvCUR_set(sv, d - SvPVX(sv));
     SvPOK_on(sv);
-    if (has_utf)
+    if (has_utf8)
        SvUTF8_on(sv);
 
     /* shrink the sv if we allocated more than we used */
@@ -2078,9 +2066,34 @@ S_find_in_my_stash(pTHX_ char *pkgname, I32 len)
       if we already built the token before, use it.
 */
 
+#ifdef USE_PURE_BISON
+#ifdef __SC__
+#pragma segment Perl_yylex_r
+#endif
+int
+Perl_yylex_r(pTHX_ YYSTYPE *lvalp, int *lcharp)
+{
+    dTHR;
+    int r;
+
+    yylval_pointer[yyactlevel] = lvalp;
+    yychar_pointer[yyactlevel] = lcharp;
+    yyactlevel++;
+    if (yyactlevel >= YYMAXLEVEL)
+       Perl_croak(aTHX_ "panic: YYMAXLEVEL");
+
+    r = Perl_yylex(aTHX);
+
+    yyactlevel--;
+
+    return r;
+}
+#endif
+
 #ifdef __SC__
 #pragma segment Perl_yylex
 #endif
+
 int
 #ifdef USE_PURE_BISON
 Perl_yylex(pTHX_ YYSTYPE *lvalp, int *lcharp)
@@ -2096,11 +2109,6 @@ Perl_yylex(pTHX)
     GV *gv = Nullgv;
     GV **gvp = 0;
 
-#ifdef USE_PURE_BISON
-    yylval_pointer = lvalp;
-    yychar_pointer = lcharp;
-#endif
-
     /* check if there's an identifier for us to look at */
     if (PL_pending_ident) {
         /* pit holds the identifier we read and pending_ident is reset */
@@ -2506,9 +2514,34 @@ Perl_yylex(pTHX)
            goto retry;
        }
        do {
-           bool bof;
-           bof = PL_rsfp && (PerlIO_tell(PL_rsfp) == 0); /* *Before* read! */
-           if ((s = filter_gets(PL_linestr, PL_rsfp, 0)) == Nullch) {
+           bool bof = PL_rsfp ? TRUE : FALSE;
+           if (bof) {
+#ifdef PERLIO_IS_STDIO
+#  ifdef __GNU_LIBRARY__
+#    if __GNU_LIBRARY__ == 1 /* Linux glibc5 */
+#      define FTELL_FOR_PIPE_IS_BROKEN
+#    endif
+#  else
+#    ifdef __GLIBC__
+#      if __GLIBC__ == 1 /* maybe some glibc5 release had it like this? */
+#        define FTELL_FOR_PIPE_IS_BROKEN
+#      endif
+#    endif
+#  endif
+#endif
+#ifdef FTELL_FOR_PIPE_IS_BROKEN
+               /* This loses the possibility to detect the bof
+                * situation on perl -P when the libc5 is being used.
+                * Workaround?  Maybe attach some extra state to PL_rsfp?
+                */
+               if (!PL_preprocess)
+                   bof = PerlIO_tell(PL_rsfp) == 0;
+#else
+               bof = PerlIO_tell(PL_rsfp) == 0;
+#endif
+           }
+           s = filter_gets(PL_linestr, PL_rsfp, 0);
+           if (s == Nullch) {
              fake_eof:
                if (PL_rsfp) {
                    if (PL_preprocess && !PL_in_eval)
@@ -2531,6 +2564,9 @@ Perl_yylex(pTHX)
                PL_oldoldbufptr = PL_oldbufptr = s = PL_linestart = SvPVX(PL_linestr);
                sv_setpv(PL_linestr,"");
                TOKEN(';');     /* not infinite loop because rsfp is NULL now */
+           } else if (bof) {
+               PL_bufend = SvPVX(PL_linestr) + SvCUR(PL_linestr);
+               s = swallow_bom((U8*)s);
            }
            if (PL_doextract) {
                if (*s == '#' && s[1] == '!' && instr(s,"perl"))
@@ -2544,8 +2580,6 @@ Perl_yylex(pTHX)
                    PL_doextract = FALSE;
                }
            } 
-           if (bof)
-               s = swallow_bom((U8*)s);
            incline(s);
        } while (PL_doextract);
        PL_oldoldbufptr = PL_oldbufptr = PL_bufptr = PL_linestart = s;
@@ -3541,7 +3575,7 @@ Perl_yylex(pTHX)
        /* FALL THROUGH */
     case '0': case '1': case '2': case '3': case '4':
     case '5': case '6': case '7': case '8': case '9':
-       s = scan_num(s);
+       s = scan_num(s, &yylval);
        if (PL_expect == XOPERATOR)
            no_op("Number",s);
        TERM(THING);
@@ -3611,7 +3645,7 @@ Perl_yylex(pTHX)
            while (isDIGIT(*start) || *start == '_')
                start++;
            if (*start == '.' && isDIGIT(start[1])) {
-               s = scan_num(s);
+               s = scan_num(s, &yylval);
                TERM(THING);
            }
            /* avoid v123abc() or $h{v1}, allow C<print v10;> */
@@ -3622,7 +3656,7 @@ Perl_yylex(pTHX)
                gv = gv_fetchpv(s, FALSE, SVt_PVCV);
                *start = c;
                if (!gv) {
-                   s = scan_num(s);
+                   s = scan_num(s, &yylval);
                    TERM(THING);
                }
            }
@@ -4004,11 +4038,11 @@ Perl_yylex(pTHX)
                /* Mark this internal pseudo-handle as clean */
                IoFLAGS(GvIOp(gv)) |= IOf_UNTAINT;
                if (PL_preprocess)
-                   IoTYPE(GvIOp(gv)) = '|';
+                   IoTYPE(GvIOp(gv)) = IoTYPE_PIPE;
                else if ((PerlIO*)PL_rsfp == PerlIO_stdin())
-                   IoTYPE(GvIOp(gv)) = '-';
+                   IoTYPE(GvIOp(gv)) = IoTYPE_STD;
                else
-                   IoTYPE(GvIOp(gv)) = '<';
+                   IoTYPE(GvIOp(gv)) = IoTYPE_RDONLY;
 #if defined(WIN32) && !defined(PERL_TEXTMODE_SCRIPTS)
                /* if the script was opened in binmode, we need to revert
                 * it to text mode for compatibility; but only iff it has CRs
@@ -4017,7 +4051,7 @@ Perl_yylex(pTHX)
                    && PL_bufend[-1] == '\n' && PL_bufend[-2] == '\r')
                {
                    Off_t loc = 0;
-                   if (IoTYPE(GvIOp(gv)) == '<') {
+                   if (IoTYPE(GvIOp(gv)) == IoTYPE_RDONLY) {
                        loc = PerlIO_tell(PL_rsfp);
                        (void)PerlIO_seek(PL_rsfp, 0L, 0);
                    }
@@ -5116,12 +5150,12 @@ Perl_keyword(pTHX_ register char *d, I32 len)
            if (strEQ(d,"cos"))                 return -KEY_cos;
            break;
        case 4:
-           if (strEQ(d,"chop"))                return KEY_chop;
+           if (strEQ(d,"chop"))                return -KEY_chop;
            break;
        case 5:
            if (strEQ(d,"close"))               return -KEY_close;
            if (strEQ(d,"chdir"))               return -KEY_chdir;
-           if (strEQ(d,"chomp"))               return KEY_chomp;
+           if (strEQ(d,"chomp"))               return -KEY_chomp;
            if (strEQ(d,"chmod"))               return -KEY_chmod;
            if (strEQ(d,"chown"))               return -KEY_chown;
            if (strEQ(d,"crypt"))               return -KEY_crypt;
@@ -5166,7 +5200,6 @@ Perl_keyword(pTHX_ register char *d, I32 len)
        }
        break;
     case 'E':
-       if (strEQ(d,"EQ")) { deprecate(d);      return -KEY_eq;}
        if (strEQ(d,"END"))                     return KEY_END;
        break;
     case 'e':
@@ -5183,7 +5216,7 @@ Perl_keyword(pTHX_ register char *d, I32 len)
            if (strEQ(d,"exit"))                return -KEY_exit;
            if (strEQ(d,"eval"))                return KEY_eval;
            if (strEQ(d,"exec"))                return -KEY_exec;
-           if (strEQ(d,"each"))                return KEY_each;
+           if (strEQ(d,"each"))                return -KEY_each;
            break;
        case 5:
            if (strEQ(d,"elsif"))               return KEY_elsif;
@@ -5232,12 +5265,6 @@ Perl_keyword(pTHX_ register char *d, I32 len)
            break;
        }
        break;
-    case 'G':
-       if (len == 2) {
-           if (strEQ(d,"GT")) { deprecate(d);  return -KEY_gt;}
-           if (strEQ(d,"GE")) { deprecate(d);  return -KEY_ge;}
-       }
-       break;
     case 'g':
        if (strnEQ(d,"get",3)) {
            d += 3;
@@ -5333,16 +5360,10 @@ Perl_keyword(pTHX_ register char *d, I32 len)
        break;
     case 'k':
        if (len == 4) {
-           if (strEQ(d,"keys"))                return KEY_keys;
+           if (strEQ(d,"keys"))                return -KEY_keys;
            if (strEQ(d,"kill"))                return -KEY_kill;
        }
        break;
-    case 'L':
-       if (len == 2) {
-           if (strEQ(d,"LT")) { deprecate(d);  return -KEY_lt;}
-           if (strEQ(d,"LE")) { deprecate(d);  return -KEY_le;}
-       }
-       break;
     case 'l':
        switch (len) {
        case 2:
@@ -5394,9 +5415,6 @@ Perl_keyword(pTHX_ register char *d, I32 len)
            break;
        }
        break;
-    case 'N':
-       if (strEQ(d,"NE")) { deprecate(d);      return -KEY_ne;}
-       break;
     case 'n':
        if (strEQ(d,"next"))                    return KEY_next;
        if (strEQ(d,"ne"))                      return -KEY_ne;
@@ -5424,11 +5442,11 @@ Perl_keyword(pTHX_ register char *d, I32 len)
     case 'p':
        switch (len) {
        case 3:
-           if (strEQ(d,"pop"))                 return KEY_pop;
+           if (strEQ(d,"pop"))                 return -KEY_pop; 
            if (strEQ(d,"pos"))                 return KEY_pos;
            break;
        case 4:
-           if (strEQ(d,"push"))                return KEY_push;
+           if (strEQ(d,"push"))                return -KEY_push;
            if (strEQ(d,"pack"))                return -KEY_pack;
            if (strEQ(d,"pipe"))                return -KEY_pipe;
            break;
@@ -5535,7 +5553,7 @@ Perl_keyword(pTHX_ register char *d, I32 len)
        case 'h':
            switch (len) {
            case 5:
-               if (strEQ(d,"shift"))           return KEY_shift;
+               if (strEQ(d,"shift"))           return -KEY_shift;
                break;
            case 6:
                if (strEQ(d,"shmctl"))          return -KEY_shmctl;
@@ -5564,7 +5582,7 @@ Perl_keyword(pTHX_ register char *d, I32 len)
        case 'p':
            if (strEQ(d,"split"))               return KEY_split;
            if (strEQ(d,"sprintf"))             return -KEY_sprintf;
-           if (strEQ(d,"splice"))              return KEY_splice;
+           if (strEQ(d,"splice"))              return -KEY_splice;
            break;
        case 'q':
            if (strEQ(d,"sqrt"))                return -KEY_sqrt;
@@ -5644,7 +5662,7 @@ Perl_keyword(pTHX_ register char *d, I32 len)
            if (strEQ(d,"unlink"))              return -KEY_unlink;
            break;
        case 7:
-           if (strEQ(d,"unshift"))             return KEY_unshift;
+           if (strEQ(d,"unshift"))             return -KEY_unshift;
            if (strEQ(d,"ucfirst"))             return -KEY_ucfirst;
            break;
        }
@@ -5749,14 +5767,23 @@ S_new_constant(pTHX_ char *s, STRLEN len, const char *key, SV *sv, SV *pv,
     if (!table || !(PL_hints & HINT_LOCALIZE_HH)) {
        SV *msg;
        
-       why1 = "%^H is not consistent";
        why2 = strEQ(key,"charnames")
-              ? " (missing \"use charnames ...\"?)"
+              ? "(possibly a missing \"use charnames ...\")"
               : "";
-       why3 = "";
+       msg = Perl_newSVpvf(aTHX_ "Constant(%s) unknown: %s", 
+                           (type ? type: "undef"), why2);
+
+       /* This is convoluted and evil ("goto considered harmful")
+        * but I do not understand the intricacies of all the different
+        * failure modes of %^H in here.  The goal here is to make
+        * the most probable error message user-friendly. --jhi */
+
+       goto msgdone;
+
     report:
-       msg = Perl_newSVpvf(aTHX_ "constant(%s): %s%s%s", 
+       msg = Perl_newSVpvf(aTHX_ "Constant(%s): %s%s%s", 
                            (type ? type: "undef"), why1, why2, why3);
+    msgdone:
        yyerror(SvPVX(msg));
        SvREFCNT_dec(msg);
        return sv;
@@ -5782,13 +5809,12 @@ S_new_constant(pTHX_ char *s, STRLEN len, const char *key, SV *sv, SV *pv,
     SAVETMPS;
     
     PUSHMARK(SP) ;
-    EXTEND(sp, 4);
+    EXTEND(sp, 3);
     if (pv)
        PUSHs(pv);
     PUSHs(sv);
     if (pv)
        PUSHs(typesv);
-    PUSHs(cv);
     PUTBACK;
     call_sv(cv, G_SCALAR | ( PL_in_eval ? 0 : G_EVAL));
     
@@ -6555,7 +6581,7 @@ S_scan_str(pTHX_ char *start, int keep_quoted, int keep_delims)
     register char term;                        /* terminating character */
     register char *to;                 /* current position in the sv's data */
     I32 brackets = 1;                  /* bracket nesting level */
-    bool has_utf = FALSE;              /* is there any utf8 content? */
+    bool has_utf8 = FALSE;             /* is there any utf8 content? */
 
     /* skip space before the delimiter */
     if (isSPACE(*s))
@@ -6567,7 +6593,7 @@ S_scan_str(pTHX_ char *start, int keep_quoted, int keep_delims)
     /* after skipping whitespace, the next character is the terminator */
     term = *s;
     if ((term & 0x80) && UTF)
-       has_utf = TRUE;
+       has_utf8 = TRUE;
 
     /* mark where we are */
     PL_multi_start = CopLINE(PL_curcop);
@@ -6613,8 +6639,8 @@ S_scan_str(pTHX_ char *start, int keep_quoted, int keep_delims)
                   have found the terminator */
                else if (*s == term)
                    break;
-               else if (!has_utf && (*s & 0x80) && UTF)
-                   has_utf = TRUE;
+               else if (!has_utf8 && (*s & 0x80) && UTF)
+                   has_utf8 = TRUE;
                *to = *s;
            }
        }
@@ -6642,8 +6668,8 @@ S_scan_str(pTHX_ char *start, int keep_quoted, int keep_delims)
                    break;
                else if (*s == PL_multi_open)
                    brackets++;
-               else if (!has_utf && (*s & 0x80) && UTF)
-                   has_utf = TRUE;
+               else if (!has_utf8 && (*s & 0x80) && UTF)
+                   has_utf8 = TRUE;
                *to = *s;
            }
        }
@@ -6703,7 +6729,7 @@ S_scan_str(pTHX_ char *start, int keep_quoted, int keep_delims)
 
     if (keep_delims)
        sv_catpvn(sv, s, 1);
-    if (has_utf)
+    if (has_utf8)
        SvUTF8_on(sv);
     PL_multi_end = CopLINE(PL_curcop);
     s++;
@@ -6748,7 +6774,7 @@ S_scan_str(pTHX_ char *start, int keep_quoted, int keep_delims)
 */
   
 char *
-Perl_scan_num(pTHX_ char *start)
+Perl_scan_num(pTHX_ char *start, YYSTYPE* lvalp)
 {
     register char *s = start;          /* current position in buffer */
     register char *d;                  /* destination in temp buffer */
@@ -7161,9 +7187,9 @@ vstring:
     /* make the op for the constant and return */
 
     if (sv)
-       yylval.opval = newSVOP(OP_CONST, 0, sv);
+       lvalp->opval = newSVOP(OP_CONST, 0, sv);
     else
-       yylval.opval = Nullop;
+       lvalp->opval = Nullop;
 
     return s;
 }
@@ -7395,7 +7421,7 @@ Perl_yyerror(pTHX_ char *s)
        qerror(msg);
     if (PL_error_count >= 10) {
        if (PL_in_eval && SvCUR(ERRSV))
-           Perl_croak(aTHX_ "%_%s has too many errors.\n",
+           Perl_croak(aTHX_ "%"SVf"%s has too many errors.\n",
                       ERRSV, CopFILE(PL_curcop));
        else
            Perl_croak(aTHX_ "%s has too many errors.\n",
@@ -7415,18 +7441,26 @@ S_swallow_bom(pTHX_ U8 *s)
     case 0xFF:       
        if (s[1] == 0xFE) { 
            /* UTF-16 little-endian */
-#ifndef PERL_NO_UTF16_FILTER
-           U8 *news;
-#endif
            if (s[2] == 0 && s[3] == 0)  /* UTF-32 little-endian */
                Perl_croak(aTHX_ "Unsupported script encoding");
 #ifndef PERL_NO_UTF16_FILTER
+           DEBUG_p(PerlIO_printf(Perl_debug_log, "UTF-LE script encoding\n"));
            s += 2;
-           filter_add(S_utf16rev_textfilter, NULL);
-           New(898, news, (PL_bufend - (char*)s) * 3 / 2 + 1, U8);
-           PL_bufend = (char*)utf16_to_utf8((U16*)s, news,
-                                            PL_bufend - (char*)s);
-           s = news;
+           if (PL_bufend > (char*)s) {
+               U8 *news;
+               I32 newlen;
+
+               filter_add(utf16rev_textfilter, NULL);
+               New(898, news, (PL_bufend - (char*)s) * 3 / 2 + 1, U8);
+               PL_bufend = (char*)utf16_to_utf8_reversed(s, news,
+                                                PL_bufend - (char*)s - 1,
+                                                &newlen);
+               Copy(news, s, newlen, U8);
+               SvCUR_set(PL_linestr, newlen);
+               PL_bufend = SvPVX(PL_linestr) + newlen;
+               news[newlen++] = '\0';
+               Safefree(news);
+           }
 #else
            Perl_croak(aTHX_ "Unsupported script encoding");
 #endif
@@ -7435,12 +7469,23 @@ S_swallow_bom(pTHX_ U8 *s)
     case 0xFE:
        if (s[1] == 0xFF) {   /* UTF-16 big-endian */
 #ifndef PERL_NO_UTF16_FILTER
-           U8 *news;
-           filter_add(S_utf16_textfilter, NULL);
-           New(898, news, (PL_bufend - (char*)s) * 3 / 2 + 1, U8);
-           PL_bufend = (char*)utf16_to_utf8((U16*)s, news,
-                                            PL_bufend - (char*)s);
-           s = news;
+           DEBUG_p(PerlIO_printf(Perl_debug_log, "UTF-16BE script encoding\n"));
+           s += 2;
+           if (PL_bufend > (char *)s) {
+               U8 *news;
+               I32 newlen;
+
+               filter_add(utf16_textfilter, NULL);
+               New(898, news, (PL_bufend - (char*)s) * 3 / 2 + 1, U8);
+               PL_bufend = (char*)utf16_to_utf8(s, news,
+                                                PL_bufend - (char*)s,
+                                                &newlen);
+               Copy(news, s, newlen, U8);
+               SvCUR_set(PL_linestr, newlen);
+               PL_bufend = SvPVX(PL_linestr) + newlen;
+               news[newlen++] = '\0';
+               Safefree(news);
+           }
 #else
            Perl_croak(aTHX_ "Unsupported script encoding");
 #endif
@@ -7448,6 +7493,7 @@ S_swallow_bom(pTHX_ U8 *s)
        break;
     case 0xEF:
        if (slen > 2 && s[1] == 0xBB && s[2] == 0xBF) {
+           DEBUG_p(PerlIO_printf(Perl_debug_log, "UTF-8 script encoding\n"));
            s += 3;                      /* UTF-8 */
        }
        break;
@@ -7481,3 +7527,43 @@ restore_rsfp(pTHXo_ void *f)
        PerlIO_close(PL_rsfp);
     PL_rsfp = fp;
 }
+
+#ifndef PERL_NO_UTF16_FILTER
+static I32
+utf16_textfilter(pTHXo_ int idx, SV *sv, int maxlen)
+{
+    I32 count = FILTER_READ(idx+1, sv, maxlen);
+    if (count) {
+       U8* tmps;
+       U8* tend;
+       I32 newlen;
+       New(898, tmps, SvCUR(sv) * 3 / 2 + 1, U8);
+       if (!*SvPV_nolen(sv))
+       /* Game over, but don't feed an odd-length string to utf16_to_utf8 */
+       return count;
+       
+       tend = utf16_to_utf8((U8*)SvPVX(sv), tmps, SvCUR(sv), &newlen);
+       sv_usepvn(sv, (char*)tmps, tend - tmps);
+    }
+    return count;
+}
+
+static I32
+utf16rev_textfilter(pTHXo_ int idx, SV *sv, int maxlen)
+{
+    I32 count = FILTER_READ(idx+1, sv, maxlen);
+    if (count) {
+       U8* tmps;
+       U8* tend;
+       I32 newlen;
+       if (!*SvPV_nolen(sv))
+       /* Game over, but don't feed an odd-length string to utf16_to_utf8 */
+       return count;
+
+       New(898, tmps, SvCUR(sv) * 3 / 2 + 1, U8);
+       tend = utf16_to_utf8_reversed((U8*)SvPVX(sv), tmps, SvCUR(sv), &newlen);
+       sv_usepvn(sv, (char*)tmps, tend - tmps);
+    }
+    return count;
+}
+#endif