[perl #24684] Too late warning not given for CHECK block in INIT block

On Sat Dec 17 20:36:28 2011, alh wrote:
> Thanks for the report.
> 
> This is because when nothing is actually happening in the main scope of
> the program it's treated as an OP_STUB which causes Perl_newPROG() to
> skip out before setting PL_main_start; which is what the warning requires:
> 
> (Inside of Perl_newprog()):
> 
>          if (o->op_type == OP_STUB) {
>             PL_comppad_name = 0;
>             PL_compcv = 0;
>             S_op_destroy(aTHX_ o);
> 
>             return; < -- Returns here
>         }
>         PL_main_root = op_scope(sawparens(scalarvoid(o)));
>         PL_curcop = &PL_compiling;
>         PL_main_start = LINKLIST(PL_main_root); < -- This is needed
> 
> (The warning check:)
> 
>                 if (PL_main_start)
>                     Perl_ck_warner(aTHX_ packWARN(WARN_VOID),
>                                    "Too late to run CHECK block");
> 
> This warns correctly for example:
> 
>  perl -we'INIT { eval "CHECK {print qq:in check in init\n:}" } print
"hi";'
> 
> Since the CHECK blocks don't actually get run, the warning should still
> get generated. Does PL_main_start (and PL_main_root, etc..) need to get
> set even when it's just an OP_STUB?  Or is this an unlikely / illogical
> situation?

It may be very unlikely, but I would not consider it illogical to want
to eval a generated CHECK block.

-- 

Father Chrysostomos

• Re: [perl #24684] Too late warning not given for CHECK block in INIT block by Yitzchak Scott-Thoennes
• [perl #24684] Too late warning not given for CHECK block in INIT block by Matthew Horsfall via RT
• [perl #24684] Too late warning not given for CHECK block in INIT block by Father Chrysostomos via RT
• [perl #24684] Too late warning not given for CHECK block in INIT block by Father Chrysostomos via RT