X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=mg.c;h=ee705ada893a54306f32a2e94d8ab795c26b11b9;hb=32babee08ee923133079392c9eae66cc543e1115;hp=b69da05403850530429f3b41c8ffdd743fb26856;hpb=d99b02a1a9949639f16470065ea5568cd92f788d;p=p5sagit%2Fp5-mst-13.2.git

diff --git a/mg.c b/mg.c
index b69da05..ee705ad 100644
--- a/mg.c
+++ b/mg.c
@@ -1,7 +1,7 @@
 /*    mg.c
  *
  *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
- *    2000, 2001, 2002, 2003, by Larry Wall and others
+ *    2000, 2001, 2002, 2003, 2004, by Larry Wall and others
  *
  *    You may distribute under the terms of either the GNU General Public
  *    License or the Artistic License, as specified in the README file.
@@ -15,6 +15,24 @@
 
 /*
 =head1 Magical Functions
+
+"Magic" is special data attached to SV structures in order to give them
+"magical" properties.  When any Perl code tries to read from, or assign to,
+an SV marked as magical, it calls the 'get' or 'set' function associated
+with that SV's magic. A get is called prior to reading an SV, in order to
+give it a chance to update its internal value (get on $. writes the line
+number of the last read filehandle into to the SV's IV slot), while
+set is called after an SV has been written to, in order to allow it to make
+use of its changed value (set on $/ copies the SV's new value to the
+PL_rs global variable).
+
+Magic is implemented as a linked list of MAGIC structures attached to the
+SV. Each MAGIC struct holds the type of the magic, a pointer to an array
+of functions that implement the get(), set(), length() etc functions,
+plus space for some flags and pointers. For example, a tied variable has
+a MAGIC structure that contains a pointer to the object associated with the
+tie.
+
 */
 
 #include "EXTERN.h"
@@ -48,6 +66,14 @@ Signal_t Perl_csighandler(int sig);
 static void restore_magic(pTHX_ void *p);
 static void unwind_handler_stack(pTHX_ void *p);
 
+#ifdef __Lynx__
+/* Missing protos on LynxOS */
+void setruid(uid_t id);
+void seteuid(uid_t id);
+void setrgid(uid_t id);
+void setegid(uid_t id);
+#endif
+
 /*
  * Use the "DESTRUCTOR" scope cleanup to reinstate magic.
  */
@@ -121,6 +147,18 @@ Perl_mg_get(pTHX_ SV *sv)
     int new = 0;
     MAGIC *newmg, *head, *cur, *mg;
     I32 mgs_ix = SSNEW(sizeof(MGS));
+    int was_temp = SvTEMP(sv);
+    /* guard against sv having being freed midway by holding a private
+       reference. */
+
+    /* sv_2mortal has this side effect of turning on the TEMP flag, which can
+       cause the SV's buffer to get stolen (and maybe other stuff).
+       So restore it.
+    */
+    sv_2mortal(SvREFCNT_inc(sv));
+    if (!was_temp) {
+	SvTEMP_off(sv);
+    }
 
     save_magic(mgs_ix, sv);
 
@@ -135,10 +173,10 @@ Perl_mg_get(pTHX_ SV *sv)
 	if (!(mg->mg_flags & MGf_GSKIP) && vtbl && vtbl->svt_get) {
 	    CALL_FPTR(vtbl->svt_get)(aTHX_ sv, mg);
 
-	    /* guard against sv having been freed */
-	    if (SvTYPE(sv) == SVTYPEMASK) {
-		Perl_croak(aTHX_ "Tied variable freed while still in use");
-	    }
+	    /* guard against magic having been deleted - eg FETCH calling
+	     * untie */
+	    if (!SvMAGIC(sv))
+		break;
 
 	    /* Don't restore the flags for this entry if it was deleted. */
 	    if (mg->mg_flags & MGf_GSKIP)
@@ -166,6 +204,12 @@ Perl_mg_get(pTHX_ SV *sv)
     }
 
     restore_magic(aTHX_ INT2PTR(void *, (IV)mgs_ix));
+
+    if (SvREFCNT(sv) == 1) {
+	/* We hold the last reference to this SV, which implies that the
+	   SV was deleted as a side effect of the routines we called.  */
+	(void)SvOK_off(sv);
+    }
     return 0;
 }
 
@@ -372,7 +416,7 @@ Perl_mg_free(pTHX_ SV *sv)
 	if (vtbl && vtbl->svt_free)
 	    CALL_FPTR(vtbl->svt_free)(aTHX_ sv, mg);
 	if (mg->mg_ptr && mg->mg_type != PERL_MAGIC_regex_global) {
-	    if (mg->mg_len > 0)
+	    if (mg->mg_len > 0 || mg->mg_type == PERL_MAGIC_utf8)
 		Safefree(mg->mg_ptr);
 	    else if (mg->mg_len == HEf_SVKEY)
 		SvREFCNT_dec((SV*)mg->mg_ptr);
@@ -385,10 +429,7 @@ Perl_mg_free(pTHX_ SV *sv)
     return 0;
 }
 
-
-#if !defined(NSIG) || defined(M_UNIX) || defined(M_XENIX)
 #include <signal.h>
-#endif
 
 U32
 Perl_magic_regdata_cnt(pTHX_ SV *sv, MAGIC *mg)
@@ -482,12 +523,12 @@ Perl_magic_len(pTHX_ SV *sv, MAGIC *mg)
 	    }
 	    else {
 		if (ckWARN(WARN_UNINITIALIZED))
-		    report_uninit();
+		    report_uninit(sv);
 	    }
 	}
 	else {
 	    if (ckWARN(WARN_UNINITIALIZED))
-		report_uninit();
+		report_uninit(sv);
 	}
 	return 0;
     case '+':
@@ -543,7 +584,7 @@ int
 Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
 {
     register I32 paren;
-    register char *s;
+    register char *s = NULL;
     register I32 i;
     register REGEXP *rx;
 
@@ -557,9 +598,6 @@ Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
 
     case '\004':		/* ^D */
 	sv_setiv(sv, (IV)(PL_debug & DEBUG_MASK));
-#if defined(YYDEBUG) && defined(DEBUGGING)
-	PL_yydebug = DEBUG_p_TEST;
-#endif
 	break;
     case '\005':  /* ^E */
 	 if (*(mg->mg_ptr+1) == '\0') {
@@ -611,8 +649,12 @@ Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
 		  SetLastError(dwErr);
 	     }
 #else
-	     sv_setnv(sv, (NV)errno);
-	     sv_setpv(sv, errno ? Strerror(errno) : "");
+	     {
+		 int saveerrno = errno;
+		 sv_setnv(sv, (NV)errno);
+		 sv_setpv(sv, errno ? Strerror(errno) : "");
+		 errno = saveerrno;
+	     }
 #endif
 #endif
 #endif
@@ -635,8 +677,10 @@ Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
 	    sv_setsv(sv, &PL_sv_undef);
 	break;
     case '\017':		/* ^O & ^OPEN */
-	if (*(mg->mg_ptr+1) == '\0')
+	if (*(mg->mg_ptr+1) == '\0') {
 	    sv_setpv(sv, PL_osname);
+	    SvTAINTED_off(sv);
+	}
 	else if (strEQ(mg->mg_ptr, "\017PEN")) {
 	    if (!PL_compiling.cop_io)
 		sv_setsv(sv, &PL_sv_undef);
@@ -801,7 +845,8 @@ Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
 	}
 	break;
     case '^':
-	s = IoTOP_NAME(GvIOp(PL_defoutgv));
+	if (GvIOp(PL_defoutgv))
+	    s = IoTOP_NAME(GvIOp(PL_defoutgv));
 	if (s)
 	    sv_setpv(sv,s);
 	else {
@@ -810,20 +855,24 @@ Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
 	}
 	break;
     case '~':
-	s = IoFMT_NAME(GvIOp(PL_defoutgv));
+	if (GvIOp(PL_defoutgv))
+	    s = IoFMT_NAME(GvIOp(PL_defoutgv));
 	if (!s)
 	    s = GvENAME(PL_defoutgv);
 	sv_setpv(sv,s);
 	break;
 #ifndef lint
     case '=':
-	sv_setiv(sv, (IV)IoPAGE_LEN(GvIOp(PL_defoutgv)));
+	if (GvIOp(PL_defoutgv))
+	    sv_setiv(sv, (IV)IoPAGE_LEN(GvIOp(PL_defoutgv)));
 	break;
     case '-':
-	sv_setiv(sv, (IV)IoLINES_LEFT(GvIOp(PL_defoutgv)));
+	if (GvIOp(PL_defoutgv))
+	    sv_setiv(sv, (IV)IoLINES_LEFT(GvIOp(PL_defoutgv)));
 	break;
     case '%':
-	sv_setiv(sv, (IV)IoPAGE(GvIOp(PL_defoutgv)));
+	if (GvIOp(PL_defoutgv))
+	    sv_setiv(sv, (IV)IoPAGE(GvIOp(PL_defoutgv)));
 	break;
 #endif
     case ':':
@@ -834,7 +883,8 @@ Perl_magic_get(pTHX_ SV *sv, MAGIC *mg)
 	WITH_THR(sv_setiv(sv, (IV)PL_curcop->cop_arybase));
 	break;
     case '|':
-	sv_setiv(sv, (IV)(IoFLAGS(GvIOp(PL_defoutgv)) & IOf_FLUSH) != 0 );
+	if (GvIOp(PL_defoutgv))
+	    sv_setiv(sv, (IV)(IoFLAGS(GvIOp(PL_defoutgv)) & IOf_FLUSH) != 0 );
 	break;
     case ',':
 	break;
@@ -1018,6 +1068,7 @@ Perl_magic_set_all_env(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_clear_all_env(pTHX_ SV *sv, MAGIC *mg)
 {
+#ifndef PERL_MICRO
 #if defined(VMS) || defined(EPOC)
     Perl_die(aTHX_ "Can't make list assignment to %%ENV on this system");
 #else
@@ -1044,7 +1095,8 @@ Perl_magic_clear_all_env(pTHX_ SV *sv, MAGIC *mg)
     }
 #    endif /* USE_ENVIRON_ARRAY */
 #   endif /* PERL_IMPLICIT_SYS || WIN32 */
-#endif /* VMS || EPC */
+#endif /* VMS || EPOC */
+#endif /* !PERL_MICRO */
     return 0;
 }
 
@@ -1144,7 +1196,7 @@ Perl_magic_clearsig(pTHX_ SV *sv, MAGIC *mg)
 #endif
 #ifdef FAKE_DEFAULT_SIGNAL_HANDLERS
 	    sig_defaulting[i] = 1;
-	    (void)rsignal(i, &Perl_csighandler);
+	    (void)rsignal(i, PL_csighandlerp);
 #else
 	    (void)rsignal(i, SIG_DFL);
 #endif
@@ -1183,7 +1235,7 @@ Perl_csighandler(int sig)
     dTHX;
 #endif
 #ifdef FAKE_PERSISTENT_SIGNAL_HANDLERS
-    (void) rsignal(sig, &Perl_csighandler);
+    (void) rsignal(sig, PL_csighandlerp);
     if (sig_ignoring[sig]) return;
 #endif
 #ifdef FAKE_DEFAULT_SIGNAL_HANDLERS
@@ -1213,7 +1265,7 @@ Perl_csighandler_init(void)
 #ifdef FAKE_DEFAULT_SIGNAL_HANDLERS
         dTHX;
         sig_defaulting[sig] = 1;
-        (void) rsignal(sig, &Perl_csighandler);
+        (void) rsignal(sig, PL_csighandlerp);
 #endif
 #ifdef FAKE_PERSISTENT_SIGNAL_HANDLERS
         sig_ignoring[sig] = 0;
@@ -1306,7 +1358,7 @@ Perl_magic_setsig(pTHX_ SV *sv, MAGIC *mg)
     }
     if (SvTYPE(sv) == SVt_PVGV || SvROK(sv)) {
 	if (i) {
-	    (void)rsignal(i, &Perl_csighandler);
+	    (void)rsignal(i, PL_csighandlerp);
 #ifdef HAS_SIGPROCMASK
 	    LEAVE;
 #endif
@@ -1322,7 +1374,7 @@ Perl_magic_setsig(pTHX_ SV *sv, MAGIC *mg)
 	if (i) {
 #ifdef FAKE_PERSISTENT_SIGNAL_HANDLERS
 	    sig_ignoring[i] = 1;
-	    (void)rsignal(i, &Perl_csighandler);
+	    (void)rsignal(i, PL_csighandlerp);
 #else
 	    (void)rsignal(i, SIG_IGN);
 #endif
@@ -1333,7 +1385,7 @@ Perl_magic_setsig(pTHX_ SV *sv, MAGIC *mg)
 #ifdef FAKE_DEFAULT_SIGNAL_HANDLERS
 	  {
 	    sig_defaulting[i] = 1;
-	    (void)rsignal(i, &Perl_csighandler);
+	    (void)rsignal(i, PL_csighandlerp);
 	  }
 #else
 	    (void)rsignal(i, SIG_DFL);
@@ -1348,7 +1400,7 @@ Perl_magic_setsig(pTHX_ SV *sv, MAGIC *mg)
 	if (!strchr(s,':') && !strchr(s,'\''))
 	    sv_insert(sv, 0, 0, "main::", 6);
 	if (i)
-	    (void)rsignal(i, &Perl_csighandler);
+	    (void)rsignal(i, PL_csighandlerp);
 	else
 	    *svp = SvREFCNT_inc(sv);
     }
@@ -1457,9 +1509,9 @@ S_magic_methpack(pTHX_ SV *sv, MAGIC *mg, char *meth)
 int
 Perl_magic_getpack(pTHX_ SV *sv, MAGIC *mg)
 {
-    magic_methpack(sv,mg,"FETCH");
     if (mg->mg_ptr)
 	mg->mg_flags |= MGf_GSKIP;
+    magic_methpack(sv,mg,"FETCH");
     return 0;
 }
 
@@ -1514,6 +1566,7 @@ Perl_magic_wipepack(pTHX_ SV *sv, MAGIC *mg)
     call_method("CLEAR", G_SCALAR|G_DISCARD);
     POPSTACK;
     LEAVE;
+
     return 0;
 }
 
@@ -1548,6 +1601,41 @@ Perl_magic_existspack(pTHX_ SV *sv, MAGIC *mg)
     return magic_methpack(sv,mg,"EXISTS");
 }
 
+SV *
+Perl_magic_scalarpack(pTHX_ HV *hv, MAGIC *mg)
+{
+    dSP;
+    SV *retval = &PL_sv_undef;
+    SV *tied = SvTIED_obj((SV*)hv, mg);
+    HV *pkg = SvSTASH((SV*)SvRV(tied));
+   
+    if (!gv_fetchmethod_autoload(pkg, "SCALAR", FALSE)) {
+        SV *key;
+        if (HvEITER(hv))
+            /* we are in an iteration so the hash cannot be empty */
+            return &PL_sv_yes;
+        /* no xhv_eiter so now use FIRSTKEY */
+        key = sv_newmortal();
+        magic_nextpack((SV*)hv, mg, key);
+        HvEITER(hv) = NULL;     /* need to reset iterator */
+        return SvOK(key) ? &PL_sv_yes : &PL_sv_no;
+    }
+   
+    /* there is a SCALAR method that we can call */
+    ENTER;
+    PUSHSTACKi(PERLSI_MAGIC);
+    PUSHMARK(SP);
+    EXTEND(SP, 1);
+    PUSHs(tied);
+    PUTBACK;
+
+    if (call_method("SCALAR", G_SCALAR))
+        retval = *PL_stack_sp--; 
+    POPSTACK;
+    LEAVE;
+    return retval;
+}
+
 int
 Perl_magic_setdbline(pTHX_ SV *sv, MAGIC *mg)
 {
@@ -1724,16 +1812,21 @@ Perl_magic_setsubstr(pTHX_ SV *sv, MAGIC *mg)
 	sv_utf8_upgrade(lsv);
  	sv_pos_u2b(lsv, &lvoff, &lvlen);
 	sv_insert(lsv, lvoff, lvlen, tmps, len);
+	LvTARGLEN(sv) = sv_len_utf8(sv);
 	SvUTF8_on(lsv);
     }
     else if (lsv && SvUTF8(lsv)) {
 	sv_pos_u2b(lsv, &lvoff, &lvlen);
+	LvTARGLEN(sv) = len;
 	tmps = (char*)bytes_to_utf8((U8*)tmps, &len);
 	sv_insert(lsv, lvoff, lvlen, tmps, len);
 	Safefree(tmps);
     }
-    else
-        sv_insert(lsv, lvoff, lvlen, tmps, len);
+    else {
+	sv_insert(lsv, lvoff, lvlen, tmps, len);
+	LvTARGLEN(sv) = len;
+    }
+
 
     return 0;
 }
@@ -1870,14 +1963,14 @@ Perl_magic_killbackrefs(pTHX_ SV *sv, MAGIC *mg)
     SV **svp = AvARRAY(av);
     I32 i = AvFILLp(av);
     while (i >= 0) {
-	if (svp[i] && svp[i] != &PL_sv_undef) {
+	if (svp[i]) {
 	    if (!SvWEAKREF(svp[i]))
 		Perl_croak(aTHX_ "panic: magic_killbackrefs");
 	    /* XXX Should we check that it hasn't changed? */
 	    SvRV(svp[i]) = 0;
 	    (void)SvOK_off(svp[i]);
 	    SvWEAKREF_off(svp[i]);
-	    svp[i] = &PL_sv_undef;
+	    svp[i] = Nullsv;
 	}
 	i--;
     }
@@ -2032,12 +2125,14 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
 	break;
     case '\017':	/* ^O */
 	if (*(mg->mg_ptr+1) == '\0') {
-	    if (PL_osname)
+	    if (PL_osname) {
 		Safefree(PL_osname);
-	    if (SvOK(sv))
-		PL_osname = savepv(SvPV(sv,len));
-	    else
 		PL_osname = Nullch;
+	    }
+	    if (SvOK(sv)) {
+		TAINT_PROPER("assigning to $^O");
+		PL_osname = savepv(SvPV(sv,len));
+	    }
 	}
 	else if (strEQ(mg->mg_ptr, "\017PEN")) {
 	    if (!PL_compiling.cop_io)
@@ -2048,7 +2143,8 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
 	break;
     case '\020':	/* ^P */
 	PL_perldb = SvIOK(sv) ? SvIVX(sv) : sv_2iv(sv);
-	if (PL_perldb && !PL_DBsingle)
+	if ((PERLDB_SUB || PERLDB_LINE || PERLDB_SUBLINE || PERLDB_ASSERTION)
+		&& !PL_DBsingle)
 	    init_debugger();
 	break;
     case '\024':	/* ^T */
@@ -2220,9 +2316,14 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
 #ifdef HAS_SETRESUID
       (void)setresuid((Uid_t)PL_uid, (Uid_t)-1, (Uid_t)-1);
 #else
-	if (PL_uid == PL_euid)		/* special case $< = $> */
+	if (PL_uid == PL_euid) {		/* special case $< = $> */
+#ifdef PERL_DARWIN
+	    /* workaround for Darwin's setuid peculiarity, cf [perl #24122] */
+	    if (PL_uid != 0 && PerlProc_getuid() == 0)
+		(void)PerlProc_setuid(0);
+#endif
 	    (void)PerlProc_setuid(PL_uid);
-	else {
+	} else {
 	    PL_uid = PerlProc_getuid();
 	    Perl_croak(aTHX_ "setruid() not implemented");
 	}
@@ -2375,10 +2476,10 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
 #endif
 	/* PL_origalen is set in perl_parse(). */
 	s = SvPV_force(sv,len);
-	if (len >= (I32)PL_origalen) {
-	    /* Longer than original, will be truncated. */
-	    Copy(s, PL_origargv[0], PL_origalen, char);
-	    PL_origargv[0][PL_origalen - 1] = 0;
+	if (len >= (STRLEN)PL_origalen-1) {
+	    /* Longer than original, will be truncated. We assume that
+             * PL_origalen bytes are available. */
+	    Copy(s, PL_origargv[0], PL_origalen-1, char);
 	}
 	else {
 	    /* Shorter than original, will be padded. */
@@ -2391,9 +2492,10 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
 		    * --jhi */
 		   (int)' ',
 		   PL_origalen - len - 1);
-	    for (i = 1; i < PL_origargc; i++)
-		 PL_origargv[i] = 0;
 	}
+	PL_origargv[0][PL_origalen-1] = 0;
+	for (i = 1; i < PL_origargc; i++)
+	    PL_origargv[i] = 0;
 	UNLOCK_DOLLARZERO_MUTEX;
 	break;
 #endif
@@ -2445,8 +2547,6 @@ Perl_sighandler(int sig)
 	flags |= 1;
     if (PL_markstack_ptr < PL_markstack_max - 2)
 	flags |= 4;
-    if (PL_retstack_ix < PL_retstack_max - 2)
-	flags |= 8;
     if (PL_scopestack_ix < PL_scopestack_max - 3)
 	flags |= 16;
 
@@ -2464,10 +2564,6 @@ Perl_sighandler(int sig)
     }
     if (flags & 4)
 	PL_markstack_ptr++;		/* Protect mark. */
-    if (flags & 8) {
-	PL_retstack_ix++;
-	PL_retstack[PL_retstack_ix] = NULL;
-    }
     if (flags & 16)
 	PL_scopestack_ix += 1;
     /* sv_2cv is too complicated, try a simpler variant first: */
@@ -2518,7 +2614,7 @@ Perl_sighandler(int sig)
 #else
 	/* Not clear if this will work */
 	(void)rsignal(sig, SIG_IGN);
-	(void)rsignal(sig, &Perl_csighandler);
+	(void)rsignal(sig, PL_csighandlerp);
 #endif
 #endif /* !PERL_MICRO */
 	Perl_die(aTHX_ Nullformat);
@@ -2528,8 +2624,6 @@ cleanup:
 	PL_savestack_ix -= 8; /* Unprotect save in progress. */
     if (flags & 4)
 	PL_markstack_ptr--;
-    if (flags & 8)
-	PL_retstack_ix--;
     if (flags & 16)
 	PL_scopestack_ix -= 1;
     if (flags & 64)
@@ -2553,6 +2647,13 @@ restore_magic(pTHX_ void *p)
 
     if (SvTYPE(sv) >= SVt_PVMG && SvMAGIC(sv))
     {
+#ifdef PERL_COPY_ON_WRITE
+	/* While magic was saved (and off) sv_setsv may well have seen
+	   this SV as a prime candidate for COW.  */
+	if (SvIsCOW(sv))
+	    sv_force_normal(sv);
+#endif
+
 	if (mgs->mgs_flags)
 	    SvFLAGS(sv) |= mgs->mgs_flags;
 	else