This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
y2038 time checks have overflow checks. Added documentation and
[perl5.git] / pp_ctl.c
index 2d3648b..fc75c72 100644 (file)
--- a/pp_ctl.c
+++ b/pp_ctl.c
@@ -231,10 +231,9 @@ PP(pp_substcont)
        if (!(cx->sb_rxtainted & 2) && SvTAINTED(TOPs))
            cx->sb_rxtainted |= 2;
        sv_catsv(dstr, POPs);
-       FREETMPS; /* Prevent excess tmp stack */
 
        /* Are we done */
-       if (cx->sb_once || !CALLREGEXEC(rx, s, cx->sb_strend, orig,
+       if (CxONCE(cx) || !CALLREGEXEC(rx, s, cx->sb_strend, orig,
                                     s == m, cx->sb_targ, NULL,
                                     ((cx->sb_rflags & REXEC_COPY_STR)
                                      ? (REXEC_IGNOREPOS|REXEC_NOT_FIRST)
@@ -298,7 +297,6 @@ PP(pp_substcont)
     { /* Update the pos() information. */
        SV * const sv = cx->sb_targ;
        MAGIC *mg;
-       I32 i;
        SvUPGRADE(sv, SVt_PVMG);
        if (!(mg = mg_find(sv, PERL_MAGIC_regex_global))) {
 #ifdef PERL_OLD_COPY_ON_WRITE
@@ -308,10 +306,7 @@ PP(pp_substcont)
            mg = sv_magicext(sv, NULL, PERL_MAGIC_regex_global, &PL_vtbl_mglob,
                             NULL, 0);
        }
-       i = m - orig;
-       if (DO_UTF8(sv))
-           sv_pos_b2u(sv, &i);
-       mg->mg_len = i;
+       mg->mg_len = m - orig;
     }
     if (old != rx)
        (void)ReREFCNT_inc(rx);
@@ -325,6 +320,8 @@ Perl_rxres_save(pTHX_ void **rsp, REGEXP *rx)
 {
     UV *p = (UV*)*rsp;
     U32 i;
+
+    PERL_ARGS_ASSERT_RXRES_SAVE;
     PERL_UNUSED_CONTEXT;
 
     if (!p || p[1] < RX_NPARENS(rx)) {
@@ -363,6 +360,8 @@ Perl_rxres_restore(pTHX_ void **rsp, REGEXP *rx)
 {
     UV *p = (UV*)*rsp;
     U32 i;
+
+    PERL_ARGS_ASSERT_RXRES_RESTORE;
     PERL_UNUSED_CONTEXT;
 
     RX_MATCH_COPY_FREE(rx);
@@ -390,6 +389,8 @@ void
 Perl_rxres_free(pTHX_ void **rsp)
 {
     UV * const p = (UV*)*rsp;
+
+    PERL_ARGS_ASSERT_RXRES_FREE;
     PERL_UNUSED_CONTEXT;
 
     if (p) {
@@ -437,7 +438,6 @@ PP(pp_formline)
     SV * nsv = NULL;
     OP * parseres = NULL;
     const char *fmt;
-    bool oneline;
 
     if (!SvMAGICAL(tmpForm) || !SvCOMPILED(tmpForm)) {
        if (SvREADONLY(tmpForm)) {
@@ -503,6 +503,7 @@ PP(pp_formline)
                *t = '\0';
                sv_catpvn_utf8_upgrade(PL_formtarget, f, arg, nsv);
                t = SvEND(PL_formtarget);
+               f += arg;
                break;
            }
            if (!targ_is_utf8 && DO_UTF8(tmpForm)) {
@@ -763,51 +764,76 @@ PP(pp_formline)
 
        case FF_LINESNGL:
            chopspace = 0;
-           oneline = TRUE;
-           goto ff_line;
        case FF_LINEGLOB:
-           oneline = FALSE;
-       ff_line:
            {
+               const bool oneline = fpc[-1] == FF_LINESNGL;
                const char *s = item = SvPV_const(sv, len);
+               item_is_utf8 = DO_UTF8(sv);
                itemsize = len;
-               if ((item_is_utf8 = DO_UTF8(sv)))
-                   itemsize = sv_len_utf8(sv);
                if (itemsize) {
-                   bool chopped = FALSE;
+                   STRLEN to_copy = itemsize;
                    const char *const send = s + len;
+                   const U8 *source = (const U8 *) s;
+                   U8 *tmp = NULL;
+
                    gotsome = TRUE;
                    chophere = s + itemsize;
                    while (s < send) {
                        if (*s++ == '\n') {
                            if (oneline) {
-                               chopped = TRUE;
+                               to_copy = s - SvPVX_const(sv) - 1;
                                chophere = s;
                                break;
                            } else {
                                if (s == send) {
                                    itemsize--;
-                                   chopped = TRUE;
+                                   to_copy--;
                                } else
                                    lines++;
                            }
                        }
                    }
-                   SvCUR_set(PL_formtarget, t - SvPVX_const(PL_formtarget));
-                   if (targ_is_utf8)
-                       SvUTF8_on(PL_formtarget);
-                   if (oneline) {
-                       SvCUR_set(sv, chophere - item);
-                       sv_catsv(PL_formtarget, sv);
-                       SvCUR_set(sv, itemsize);
-                   } else
-                       sv_catsv(PL_formtarget, sv);
-                   if (chopped)
-                       SvCUR_set(PL_formtarget, SvCUR(PL_formtarget) - 1);
-                   SvGROW(PL_formtarget, SvCUR(PL_formtarget) + fudge + 1);
+                   if (targ_is_utf8 && !item_is_utf8) {
+                       source = tmp = bytes_to_utf8(source, &to_copy);
+                       SvCUR_set(PL_formtarget,
+                                 t - SvPVX_const(PL_formtarget));
+                   } else {
+                       if (item_is_utf8 && !targ_is_utf8) {
+                           /* Upgrade targ to UTF8, and then we reduce it to
+                              a problem we have a simple solution for.  */
+                           SvCUR_set(PL_formtarget,
+                                     t - SvPVX_const(PL_formtarget));
+                           targ_is_utf8 = TRUE;
+                           /* Don't need get magic.  */
+                           sv_utf8_upgrade_flags(PL_formtarget, 0);
+                       } else {
+                           SvCUR_set(PL_formtarget,
+                                     t - SvPVX_const(PL_formtarget));
+                       }
+
+                       /* Easy. They agree.  */
+                       assert (item_is_utf8 == targ_is_utf8);
+                   }
+                   SvGROW(PL_formtarget,
+                          SvCUR(PL_formtarget) + to_copy + fudge + 1);
                    t = SvPVX(PL_formtarget) + SvCUR(PL_formtarget);
-                   if (item_is_utf8)
-                       targ_is_utf8 = TRUE;
+
+                   Copy(source, t, to_copy, char);
+                   t += to_copy;
+                   SvCUR_set(PL_formtarget, SvCUR(PL_formtarget) + to_copy);
+                   if (item_is_utf8) {
+                       if (SvGMAGICAL(sv)) {
+                           /* Mustn't call sv_pos_b2u() as it does a second
+                              mg_get(). Is this a bug? Do we need a _flags()
+                              variant? */
+                           itemsize = utf8_length(source, source + itemsize);
+                       } else {
+                           sv_pos_b2u(sv, &itemsize);
+                       }
+                       assert(!tmp);
+                   } else if (tmp) {
+                       Safefree(tmp);
+                   }
                }
                break;
            }
@@ -1224,14 +1250,17 @@ PP(pp_flop)
 
 static const char * const context_name[] = {
     "pseudo-block",
+    "when",
+    NULL, /* CXt_BLOCK never actually needs "block" */
+    "given",
+    NULL, /* CXt_LOOP_FOR never actually needs "loop" */
+    NULL, /* CXt_LOOP_PLAIN never actually needs "loop" */
+    NULL, /* CXt_LOOP_LAZYSV never actually needs "loop" */
+    NULL, /* CXt_LOOP_LAZYIV never actually needs "loop" */
     "subroutine",
+    "format",
     "eval",
-    "loop",
     "substitution",
-    "block",
-    "format",
-    "given",
-    "when"
 };
 
 STATIC I32
@@ -1240,6 +1269,8 @@ S_dopoptolabel(pTHX_ const char *label)
     dVAR;
     register I32 i;
 
+    PERL_ARGS_ASSERT_DOPOPTOLABEL;
+
     for (i = cxstack_ix; i >= 0; i--) {
        register const PERL_CONTEXT * const cx = &cxstack[i];
        switch (CxTYPE(cx)) {
@@ -1256,7 +1287,10 @@ S_dopoptolabel(pTHX_ const char *label)
            if (CxTYPE(cx) == CXt_NULL)
                return -1;
            break;
-       case CXt_LOOP:
+       case CXt_LOOP_LAZYIV:
+       case CXt_LOOP_LAZYSV:
+       case CXt_LOOP_FOR:
+       case CXt_LOOP_PLAIN:
            if ( !CxLABEL(cx) || strNE(label, CxLABEL(cx)) ) {
                DEBUG_l(Perl_deb(aTHX_ "(Skipping label #%ld %s)\n",
                        (long)i, CxLABEL(cx)));
@@ -1319,6 +1353,9 @@ S_dopoptosub_at(pTHX_ const PERL_CONTEXT *cxstk, I32 startingblock)
 {
     dVAR;
     I32 i;
+
+    PERL_ARGS_ASSERT_DOPOPTOSUB_AT;
+
     for (i = startingblock; i >= 0; i--) {
        register const PERL_CONTEXT * const cx = &cxstk[i];
        switch (CxTYPE(cx)) {
@@ -1371,7 +1408,10 @@ S_dopoptoloop(pTHX_ I32 startingblock)
            if ((CxTYPE(cx)) == CXt_NULL)
                return -1;
            break;
-       case CXt_LOOP:
+       case CXt_LOOP_LAZYIV:
+       case CXt_LOOP_LAZYSV:
+       case CXt_LOOP_FOR:
+       case CXt_LOOP_PLAIN:
            DEBUG_l( Perl_deb(aTHX_ "(Found loop #%ld)\n", (long)i));
            return i;
        }
@@ -1392,7 +1432,12 @@ S_dopoptogiven(pTHX_ I32 startingblock)
        case CXt_GIVEN:
            DEBUG_l( Perl_deb(aTHX_ "(Found given #%ld)\n", (long)i));
            return i;
-       case CXt_LOOP:
+       case CXt_LOOP_PLAIN:
+           assert(!CxFOREACHDEF(cx));
+           break;
+       case CXt_LOOP_LAZYIV:
+       case CXt_LOOP_LAZYSV:
+       case CXt_LOOP_FOR:
            if (CxFOREACHDEF(cx)) {
                DEBUG_l( Perl_deb(aTHX_ "(Found foreach #%ld)\n", (long)i));
                return i;
@@ -1443,7 +1488,10 @@ Perl_dounwind(pTHX_ I32 cxix)
        case CXt_EVAL:
            POPEVAL(cx);
            break;
-       case CXt_LOOP:
+       case CXt_LOOP_LAZYIV:
+       case CXt_LOOP_LAZYSV:
+       case CXt_LOOP_FOR:
+       case CXt_LOOP_PLAIN:
            POPLOOP(cx);
            break;
        case CXt_NULL:
@@ -1461,6 +1509,9 @@ void
 Perl_qerror(pTHX_ SV *err)
 {
     dVAR;
+
+    PERL_ARGS_ASSERT_QERROR;
+
     if (PL_in_eval)
        sv_catsv(ERRSV, err);
     else if (PL_errors)
@@ -1654,11 +1705,11 @@ PP(pp_caller)
            SV * const sv = newSV(0);
            gv_efullname3(sv, cvgv, NULL);
            mPUSHs(sv);
-           mPUSHi((I32)CxHASARGS(cx));
+           PUSHs(boolSV(CxHASARGS(cx)));
        }
        else {
            PUSHs(newSVpvs_flags("(unknown)", SVs_TEMP));
-           mPUSHi((I32)CxHASARGS(cx));
+           PUSHs(boolSV(CxHASARGS(cx)));
        }
     }
     else {
@@ -1669,10 +1720,10 @@ PP(pp_caller)
     if (gimme == G_VOID)
        PUSHs(&PL_sv_undef);
     else
-       mPUSHi(gimme & G_ARRAY);
+       PUSHs(boolSV((gimme & G_WANT) == G_ARRAY));
     if (CxTYPE(cx) == CXt_EVAL) {
        /* eval STRING */
-       if (cx->blk_eval.old_op_type == OP_ENTEREVAL) {
+       if (CxOLD_OP_TYPE(cx) == OP_ENTEREVAL) {
            PUSHs(cx->blk_eval.cur_text);
            PUSHs(&PL_sv_no);
        }
@@ -1821,9 +1872,9 @@ PP(pp_enteriter)
     register PERL_CONTEXT *cx;
     const I32 gimme = GIMME_V;
     SV **svp;
-    U16 cxtype = CXt_LOOP | CXp_FOREACH;
+    U8 cxtype = CXt_LOOP_FOR;
 #ifdef USE_ITHREADS
-    void *iterdata;
+    PAD *iterdata;
 #endif
 
     ENTER;
@@ -1835,13 +1886,11 @@ PP(pp_enteriter)
            SAVESETSVFLAGS(PAD_SVl(PL_op->op_targ),
                    SVs_PADSTALE, SVs_PADSTALE);
        }
+       SAVEPADSVANDMORTALIZE(PL_op->op_targ);
 #ifndef USE_ITHREADS
        svp = &PAD_SVl(PL_op->op_targ);         /* "my" variable */
-       SAVESPTR(*svp);
 #else
-       SAVEPADSV(PL_op->op_targ);
-       iterdata = INT2PTR(void*, PL_op->op_targ);
-       cxtype |= CXp_PADVAR;
+       iterdata = NULL;
 #endif
     }
     else {
@@ -1850,7 +1899,7 @@ PP(pp_enteriter)
        SAVEGENERICSV(*svp);
        *svp = newSV(0);
 #ifdef USE_ITHREADS
-       iterdata = (void*)gv;
+       iterdata = (PAD*)gv;
 #endif
     }
 
@@ -1861,18 +1910,23 @@ PP(pp_enteriter)
 
     PUSHBLOCK(cx, cxtype, SP);
 #ifdef USE_ITHREADS
-    PUSHLOOP(cx, iterdata, MARK);
+    PUSHLOOP_FOR(cx, iterdata, MARK, PL_op->op_targ);
 #else
-    PUSHLOOP(cx, svp, MARK);
+    PUSHLOOP_FOR(cx, svp, MARK, 0);
 #endif
     if (PL_op->op_flags & OPf_STACKED) {
-       cx->blk_loop.iterary = (AV*)SvREFCNT_inc(POPs);
-       if (SvTYPE(cx->blk_loop.iterary) != SVt_PVAV) {
+       SV *maybe_ary = POPs;
+       if (SvTYPE(maybe_ary) != SVt_PVAV) {
            dPOPss;
-           SV * const right = (SV*)cx->blk_loop.iterary;
+           SV * const right = maybe_ary;
            SvGETMAGIC(sv);
            SvGETMAGIC(right);
            if (RANGE_IS_NUMERIC(sv,right)) {
+               cx->cx_type &= ~CXTYPEMASK;
+               cx->cx_type |= CXt_LOOP_LAZYIV;
+               /* Make sure that no-one re-orders cop.h and breaks our
+                  assumptions */
+               assert(CxTYPE(cx) == CXt_LOOP_LAZYIV);
 #ifdef NV_PRESERVES_UV
                if ((SvOK(sv) && ((SvNV(sv) < (NV)IV_MIN) ||
                                  (SvNV(sv) > (NV)IV_MAX)))
@@ -1893,34 +1947,50 @@ PP(pp_enteriter)
                                         (SvNV(right) > (NV)UV_MAX))))))
 #endif
                    DIE(aTHX_ "Range iterator outside integer range");
-               cx->blk_loop.iterix = SvIV(sv);
-               cx->blk_loop.itermax = SvIV(right);
+               cx->blk_loop.state_u.lazyiv.cur = SvIV(sv);
+               cx->blk_loop.state_u.lazyiv.end = SvIV(right);
 #ifdef DEBUGGING
                /* for correct -Dstv display */
                cx->blk_oldsp = sp - PL_stack_base;
 #endif
            }
            else {
-               cx->blk_loop.iterlval = newSVsv(sv);
-               (void) SvPV_force_nolen(cx->blk_loop.iterlval);
+               cx->cx_type &= ~CXTYPEMASK;
+               cx->cx_type |= CXt_LOOP_LAZYSV;
+               /* Make sure that no-one re-orders cop.h and breaks our
+                  assumptions */
+               assert(CxTYPE(cx) == CXt_LOOP_LAZYSV);
+               cx->blk_loop.state_u.lazysv.cur = newSVsv(sv);
+               cx->blk_loop.state_u.lazysv.end = right;
+               SvREFCNT_inc(right);
+               (void) SvPV_force_nolen(cx->blk_loop.state_u.lazysv.cur);
+               /* This will do the upgrade to SVt_PV, and warn if the value
+                  is uninitialised.  */
                (void) SvPV_nolen_const(right);
+               /* Doing this avoids a check every time in pp_iter in pp_hot.c
+                  to replace !SvOK() with a pointer to "".  */
+               if (!SvOK(right)) {
+                   SvREFCNT_dec(right);
+                   cx->blk_loop.state_u.lazysv.end = &PL_sv_no;
+               }
            }
        }
-       else if (PL_op->op_private & OPpITER_REVERSED) {
-           cx->blk_loop.itermax = 0;
-           cx->blk_loop.iterix = AvFILL(cx->blk_loop.iterary) + 1;
-
+       else /* SvTYPE(maybe_ary) == SVt_PVAV */ {
+           cx->blk_loop.state_u.ary.ary = (AV*)maybe_ary;
+           SvREFCNT_inc(maybe_ary);
+           cx->blk_loop.state_u.ary.ix =
+               (PL_op->op_private & OPpITER_REVERSED) ?
+               AvFILL(cx->blk_loop.state_u.ary.ary) + 1 :
+               -1;
        }
     }
-    else {
-       cx->blk_loop.iterary = PL_curstack;
-       AvFILLp(PL_curstack) = SP - PL_stack_base;
+    else { /* iterating over items on the stack */
+       cx->blk_loop.state_u.ary.ary = NULL; /* means to use the stack */
        if (PL_op->op_private & OPpITER_REVERSED) {
-           cx->blk_loop.itermax = MARK - PL_stack_base + 1;
-           cx->blk_loop.iterix = cx->blk_oldsp + 1;
+           cx->blk_loop.state_u.ary.ix = cx->blk_oldsp + 1;
        }
        else {
-           cx->blk_loop.iterix = MARK - PL_stack_base;
+           cx->blk_loop.state_u.ary.ix = MARK - PL_stack_base;
        }
     }
 
@@ -1937,8 +2007,8 @@ PP(pp_enterloop)
     SAVETMPS;
     ENTER;
 
-    PUSHBLOCK(cx, CXt_LOOP, SP);
-    PUSHLOOP(cx, 0, SP);
+    PUSHBLOCK(cx, CXt_LOOP_PLAIN, SP);
+    PUSHLOOP_PLAIN(cx, SP);
 
     RETURN;
 }
@@ -1953,7 +2023,7 @@ PP(pp_leaveloop)
     SV **mark;
 
     POPBLOCK(cx,newpm);
-    assert(CxTYPE(cx) == CXt_LOOP);
+    assert(CxTYPE_is_LOOP(cx));
     mark = newsp;
     newsp = PL_stack_base + cx->blk_loop.resetsp;
 
@@ -2103,8 +2173,9 @@ PP(pp_return)
     PL_curpm = newpm;  /* ... and pop $1 et al */
 
     LEAVESUB(sv);
-    if (clear_errsv)
-       sv_setpvn(ERRSV,"",0);
+    if (clear_errsv) {
+       CLEAR_ERRSV();
+    }
     return retop;
 }
 
@@ -2140,8 +2211,11 @@ PP(pp_last)
     cxstack_ix++; /* temporarily protect top context */
     mark = newsp;
     switch (CxTYPE(cx)) {
-    case CXt_LOOP:
-       pop2 = CXt_LOOP;
+    case CXt_LOOP_LAZYIV:
+    case CXt_LOOP_LAZYSV:
+    case CXt_LOOP_FOR:
+    case CXt_LOOP_PLAIN:
+       pop2 = CxTYPE(cx);
        newsp = PL_stack_base + cx->blk_loop.resetsp;
        nextop = cx->blk_loop.my_op->op_lastop->op_next;
        break;
@@ -2183,7 +2257,10 @@ PP(pp_last)
     cxstack_ix--;
     /* Stack values are safe: */
     switch (pop2) {
-    case CXt_LOOP:
+    case CXt_LOOP_LAZYIV:
+    case CXt_LOOP_PLAIN:
+    case CXt_LOOP_LAZYSV:
+    case CXt_LOOP_FOR:
        POPLOOP(cx);    /* release loop vars ... */
        LEAVE;
        break;
@@ -2273,6 +2350,8 @@ S_dofindlabel(pTHX_ OP *o, const char *label, OP **opstack, OP **oplimit)
     OP **ops = opstack;
     static const char too_deep[] = "Target of goto is too deeply nested";
 
+    PERL_ARGS_ASSERT_DOFINDLABEL;
+
     if (ops >= oplimit)
        Perl_croak(aTHX_ too_deep);
     if (o->op_type == OP_LEAVE ||
@@ -2291,7 +2370,7 @@ S_dofindlabel(pTHX_ OP *o, const char *label, OP **opstack, OP **oplimit)
        /* First try all the kids at this level, since that's likeliest. */
        for (kid = cUNOPo->op_first; kid; kid = kid->op_sibling) {
            if ((kid->op_type == OP_NEXTSTATE || kid->op_type == OP_DBSTATE) &&
-                   kCOP->cop_label && strEQ(kCOP->cop_label, label))
+                   CopLABEL(kCOP) && strEQ(CopLABEL(kCOP), label))
                return kid;
        }
        for (kid = cUNOPo->op_first; kid; kid = kid->op_sibling) {
@@ -2437,10 +2516,9 @@ PP(pp_goto)
            else {
                AV* const padlist = CvPADLIST(cv);
                if (CxTYPE(cx) == CXt_EVAL) {
-                   PL_in_eval = cx->blk_eval.old_in_eval;
+                   PL_in_eval = CxOLD_IN_EVAL(cx);
                    PL_eval_root = cx->blk_eval.old_eval_root;
                    cx->cx_type = CXt_SUB;
-                   cx->blk_sub.hasargs = 0;
                }
                cx->blk_sub.cv = cv;
                cx->blk_sub.olddepth = CvDEPTH(cv);
@@ -2542,7 +2620,10 @@ PP(pp_goto)
                    break;
                 }
                 /* else fall through */
-           case CXt_LOOP:
+           case CXt_LOOP_LAZYIV:
+           case CXt_LOOP_LAZYSV:
+           case CXt_LOOP_FOR:
+           case CXt_LOOP_PLAIN:
                gotoprobe = cx->blk_oldcop->op_sibling;
                break;
            case CXt_SUBST:
@@ -2674,6 +2755,8 @@ S_save_lines(pTHX_ AV *array, SV *sv)
     const char * const send = SvPVX_const(sv) + SvCUR(sv);
     I32 line = 1;
 
+    PERL_ARGS_ASSERT_SAVE_LINES;
+
     while (s && s < send) {
        const char *t;
        SV * const tmpstr = newSV_type(SVt_PVMG);
@@ -2761,6 +2844,8 @@ Perl_sv_compile_2op(pTHX_ SV *sv, OP** startop, const char *code, PAD** padp)
     CV* runcv = NULL;  /* initialise to avoid compiler warnings */
     STRLEN len;
 
+    PERL_ARGS_ASSERT_SV_COMPILE_2OP;
+
     ENTER;
     lex_start(sv, NULL, FALSE);
     SAVETMPS;
@@ -2808,7 +2893,7 @@ Perl_sv_compile_2op(pTHX_ SV *sv, OP** startop, const char *code, PAD** padp)
     PL_op->op_type = OP_ENTEREVAL;
     PL_op->op_flags = 0;                       /* Avoid uninit warning. */
     PUSHBLOCK(cx, CXt_EVAL|(IN_PERL_COMPILETIME ? 0 : CXp_REAL), SP);
-    PUSHEVAL(cx, 0, NULL);
+    PUSHEVAL(cx, 0);
 
     if (runtime)
        (void) doeval(G_SCALAR, startop, runcv, PL_curcop->cop_seq);
@@ -2942,7 +3027,7 @@ S_doeval(pTHX_ int gimme, OP** startop, CV* outside, U32 seq)
     if (saveop && (saveop->op_type != OP_REQUIRE) && (saveop->op_flags & OPf_SPECIAL))
        PL_in_eval |= EVAL_KEEPERR;
     else
-       sv_setpvn(ERRSV,"",0);
+       CLEAR_ERRSV();
     if (yyparse() || PL_parser->error_count || !PL_eval_root) {
        SV **newsp;                     /* Used by POPBLOCK. */
        PERL_CONTEXT *cx = &cxstack[cxstack_ix];
@@ -3000,9 +3085,9 @@ S_doeval(pTHX_ int gimme, OP** startop, CV* outside, U32 seq)
            && cLISTOPx(cUNOPx(PL_eval_root)->op_first)->op_last->op_type
            == OP_REQUIRE)
        scalar(PL_eval_root);
-    else if (gimme & G_VOID)
+    else if ((gimme & G_WANT) == G_VOID)
        scalarvoid(PL_eval_root);
-    else if (gimme & G_ARRAY)
+    else if ((gimme & G_WANT) == G_ARRAY)
        list(PL_eval_root);
     else
        scalar(PL_eval_root);
@@ -3041,6 +3126,8 @@ S_check_type_and_open(pTHX_ const char *name)
     Stat_t st;
     const int st_rc = PerlLIO_stat(name, &st);
 
+    PERL_ARGS_ASSERT_CHECK_TYPE_AND_OPEN;
+
     if (st_rc < 0 || S_ISDIR(st.st_mode) || S_ISBLK(st.st_mode)) {
        return NULL;
     }
@@ -3054,6 +3141,8 @@ S_doopen_pm(pTHX_ const char *name, const STRLEN namelen)
 {
     PerlIO *fp;
 
+    PERL_ARGS_ASSERT_DOOPEN_PM;
+
     if (namelen > 3 && memEQs(name + namelen - 3, 3, ".pm")) {
        SV *const pmcsv = newSV(namelen + 2);
        char *const pmc = SvPVX(pmcsv);
@@ -3289,11 +3378,11 @@ PP(pp_require)
                            }
                        }
 
-                       if (SvROK(arg) && SvTYPE(SvRV(arg)) == SVt_PVGV) {
+                       if (SvROK(arg) && isGV_with_GP(SvRV(arg))) {
                            arg = SvRV(arg);
                        }
 
-                       if (SvTYPE(arg) == SVt_PVGV) {
+                       if (isGV_with_GP(arg)) {
                            IO * const io = GvIO((GV *)arg);
 
                            ++filter_has_file;
@@ -3496,6 +3585,11 @@ PP(pp_require)
 
     SAVEHINTS();
     PL_hints = 0;
+    if (PL_compiling.cop_hints_hash) {
+       Perl_refcounted_he_free(aTHX_ PL_compiling.cop_hints_hash);
+       PL_compiling.cop_hints_hash = NULL;
+    }
+
     SAVECOMPILEWARNINGS();
     if (PL_dowarn & G_WARN_ALL_ON)
         PL_compiling.cop_warnings = pWARN_ALL ;
@@ -3514,7 +3608,7 @@ PP(pp_require)
 
     /* switch to eval mode */
     PUSHBLOCK(cx, CXt_EVAL, SP);
-    PUSHEVAL(cx, name, NULL);
+    PUSHEVAL(cx, name);
     cx->blk_eval.retop = PL_op->op_next;
 
     SAVECOPLINE(&PL_compiling);
@@ -3537,6 +3631,19 @@ PP(pp_require)
     return op;
 }
 
+/* This is a op added to hold the hints hash for
+   pp_entereval. The hash can be modified by the code
+   being eval'ed, so we return a copy instead. */
+
+PP(pp_hintseval)
+{
+    dVAR;
+    dSP;
+    mXPUSHs((SV*)Perl_hv_copy_hints_hv(aTHX_ (HV*)cSVOP_sv));
+    RETURN;
+}
+
+
 PP(pp_entereval)
 {
     dVAR; dSP;
@@ -3613,7 +3720,7 @@ PP(pp_entereval)
     runcv = find_runcv(&seq);
 
     PUSHBLOCK(cx, (CXt_EVAL|CXp_REAL), SP);
-    PUSHEVAL(cx, 0, NULL);
+    PUSHEVAL(cx, 0);
     cx->blk_eval.retop = PL_op->op_next;
 
     /* prepare to compile string */
@@ -3691,8 +3798,9 @@ PP(pp_leaveeval)
     }
     else {
        LEAVE;
-       if (!(save_flags & OPf_SPECIAL))
-           sv_setpvn(ERRSV,"",0);
+       if (!(save_flags & OPf_SPECIAL)) {
+           CLEAR_ERRSV();
+       }
     }
 
     RETURNOP(retop);
@@ -3730,13 +3838,13 @@ Perl_create_eval_scope(pTHX_ U32 flags)
     SAVETMPS;
 
     PUSHBLOCK(cx, (CXt_EVAL|CXp_TRYBLOCK), PL_stack_sp);
-    PUSHEVAL(cx, 0, 0);
+    PUSHEVAL(cx, 0);
 
     PL_in_eval = EVAL_INEVAL;
     if (flags & G_KEEPERR)
        PL_in_eval |= EVAL_KEEPERR;
     else
-       sv_setpvn(ERRSV,"",0);
+       CLEAR_ERRSV();
     if (flags & G_FAKINGEVAL) {
        PL_eval_root = PL_op; /* Only needed so that goto works right. */
     }
@@ -3795,7 +3903,7 @@ PP(pp_leavetry)
     PL_curpm = newpm;  /* Don't pop $1 et al till now */
 
     LEAVE;
-    sv_setpvn(ERRSV,"",0);
+    CLEAR_ERRSV();
     RETURN;
 }
 
@@ -3850,8 +3958,11 @@ S_make_matcher(pTHX_ REGEXP *re)
 {
     dVAR;
     PMOP *matcher = (PMOP *) newPMOP(OP_MATCH, OPf_WANT_SCALAR | OPf_STACKED);
+
+    PERL_ARGS_ASSERT_MAKE_MATCHER;
+
     PM_SETRE(matcher, ReREFCNT_inc(re));
-    
+
     SAVEFREEOP((OP *) matcher);
     ENTER; SAVETMPS;
     SAVEOP();
@@ -3863,6 +3974,8 @@ S_matcher_matches_sv(pTHX_ PMOP *matcher, SV *sv)
 {
     dVAR;
     dSP;
+
+    PERL_ARGS_ASSERT_MATCHER_MATCHES_SV;
     
     PL_op = (OP *) matcher;
     XPUSHs(sv);
@@ -3876,7 +3989,10 @@ STATIC void
 S_destroy_matcher(pTHX_ PMOP *matcher)
 {
     dVAR;
+
+    PERL_ARGS_ASSERT_DESTROY_MATCHER;
     PERL_UNUSED_ARG(matcher);
+
     FREETMPS;
     LEAVE;
 }
@@ -3923,6 +4039,11 @@ S_do_smartmatch(pTHX_ HV *seen_this, HV *seen_other)
        && (Other = d)) )
        
 
+#   define SM_OBJECT ( \
+          (sv_isobject(d) && (SvTYPE(SvRV(d)) != SVt_REGEXP))          \
+    ||                                                                 \
+          (sv_isobject(e) && (SvTYPE(SvRV(e)) != SVt_REGEXP)) )        \
+
 #   define SM_OTHER_REF(type) \
        (SvROK(Other) && SvTYPE(SvRV(Other)) == SVt_##type)
 
@@ -3954,6 +4075,9 @@ S_do_smartmatch(pTHX_ HV *seen_this, HV *seen_other)
     if (SvGMAGICAL(e))
        e = sv_mortalcopy(e);
 
+    if (SM_OBJECT)
+       Perl_croak(aTHX_ "Smart matching a non-overloaded object breaks encapsulation");
+
     if (SM_CV_NEP) {
        I32 c;
        
@@ -4380,6 +4504,8 @@ S_doparseform(pTHX_ SV *sv)
     bool unchopnum = FALSE;
     int maxops = 12; /* FF_LINEMARK + FF_END + 10 (\0 without preceding \n) */
 
+    PERL_ARGS_ASSERT_DOPARSEFORM;
+
     if (len == 0)
        Perl_croak(aTHX_ "Null picture in formline");
 
@@ -4622,6 +4748,8 @@ S_run_user_filter(pTHX_ int idx, SV *buf_sv, int maxlen)
     bool read_from_cache = FALSE;
     STRLEN umaxlen;
 
+    PERL_ARGS_ASSERT_RUN_USER_FILTER;
+
     assert(maxlen >= 0);
     umaxlen = maxlen;
 
@@ -4788,6 +4916,8 @@ S_run_user_filter(pTHX_ int idx, SV *buf_sv, int maxlen)
 static bool
 S_path_is_absolute(const char *name)
 {
+    PERL_ARGS_ASSERT_PATH_IS_ABSOLUTE;
+
     if (PERL_FILE_IS_ABSOLUTE(name)
 #ifdef MACOS_TRADITIONAL
        || (*name == ':')