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#define PERL_NO_GET_CONTEXT |
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|
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#include "EXTERN.h" |
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#include "perl.h" |
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#include "XSUB.h" |
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|
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/* apparently < 5.8.8 */ |
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#ifndef SvSTASH_set |
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# define SvSTASH_set(x,a) SvSTASH(x) = (a) |
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#endif |
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|
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#ifndef PERL_MAGIC_ext |
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# define PERL_MAGIC_ext '~' |
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#endif |
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|
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static HV *guard_stash; |
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|
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static SV * |
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guard_get_cv (pTHX_ SV *cb_sv) |
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{ |
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HV *st; |
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GV *gvp; |
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CV *cv = sv_2cv (cb_sv, &st, &gvp, 0); |
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|
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if (!cv) |
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croak ("expected a CODE reference for guard"); |
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|
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return (SV *)cv; |
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} |
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|
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static void |
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exec_guard_cb (pTHX_ SV *cb) |
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{ |
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dSP; |
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SV *saveerr = SvOK (ERRSV) ? sv_mortalcopy (ERRSV) : 0; |
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SV *savedie = PL_diehook; |
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|
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PL_diehook = 0; |
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|
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PUSHSTACKi (PERLSI_DESTROY); |
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|
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PUSHMARK (SP); |
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PUTBACK; |
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call_sv (cb, G_VOID | G_DISCARD | G_EVAL); |
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|
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if (SvTRUE (ERRSV)) |
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{ |
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SPAGAIN; |
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|
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PUSHMARK (SP); |
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PUTBACK; |
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call_sv (get_sv ("Guard::DIED", 1), G_VOID | G_DISCARD | G_EVAL | G_KEEPERR); |
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|
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sv_setpvn (ERRSV, "", 0); |
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} |
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|
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if (saveerr) |
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sv_setsv (ERRSV, saveerr); |
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|
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{ |
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SV *oldhook = PL_diehook; |
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PL_diehook = savedie; |
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SvREFCNT_dec (oldhook); |
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} |
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|
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POPSTACK; |
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} |
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|
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static void |
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scope_guard_cb (pTHX_ void *cv) |
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{ |
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exec_guard_cb (aTHX_ sv_2mortal ((SV *)cv)); |
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} |
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|
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static int |
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guard_free (pTHX_ SV *cv, MAGIC *mg) |
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{ |
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exec_guard_cb (aTHX_ mg->mg_obj); |
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|
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return 0; |
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} |
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|
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static MGVTBL guard_vtbl = { |
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0, 0, 0, 0, |
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guard_free |
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}; |
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|
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MODULE = Guard PACKAGE = Guard |
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|
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BOOT: |
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guard_stash = gv_stashpv ("Guard", 1); |
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CvNODEBUG_on (get_cv ("Guard::scope_guard", 0)); /* otherwise calling scope can be the debugger */ |
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|
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void |
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scope_guard (SV *block) |
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PROTOTYPE: & |
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CODE: |
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LEAVE; /* unfortunately, perl sandwiches XS calls into ENTER/LEAVE */ |
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SAVEDESTRUCTOR_X (scope_guard_cb, (void *)SvREFCNT_inc (guard_get_cv (aTHX_ block))); |
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ENTER; /* unfortunately, perl sandwiches XS calls into ENTER/LEAVE */ |
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|
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SV * |
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guard (SV *block) |
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PROTOTYPE: & |
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CODE: |
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{ |
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SV *cv = guard_get_cv (aTHX_ block); |
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SV *guard = NEWSV (0, 0); |
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SvUPGRADE (guard, SVt_PVMG); |
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sv_magicext (guard, cv, PERL_MAGIC_ext, &guard_vtbl, 0, 0); |
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RETVAL = newRV_noinc (guard); |
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SvOBJECT_on (guard); |
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++PL_sv_objcount; |
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SvSTASH_set (guard, (HV*)SvREFCNT_inc ((SV *)guard_stash)); |
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} |
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OUTPUT: |
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RETVAL |
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|
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void |
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cancel (SV *guard) |
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PROTOTYPE: $ |
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CODE: |
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{ |
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MAGIC *mg; |
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if (!SvROK (guard) |
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|| !(mg = mg_find (SvRV (guard), PERL_MAGIC_ext)) |
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|| mg->mg_virtual != &guard_vtbl) |
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croak ("Guard::cancel called on a non-guard object"); |
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|
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SvREFCNT_dec (mg->mg_obj); |
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mg->mg_obj = 0; |
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mg->mg_virtual = 0; |
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} |
