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[perl #93992] Confused application of subroutine prototypes

From:
Father Chrysostomos
Date:
July 3, 2011 14:52
Subject:
[perl #93992] Confused application of subroutine prototypes
Message ID:
rt-3.6.HEAD-16080-1309729927-416.93992-75-0@perl.org
# New Ticket Created by  Father Chrysostomos 
# Please include the string:  [perl #93992]
# in the subject line of all future correspondence about this issue. 
# <URL: http://rt.perl.org/rt3/Ticket/Display.html?id=93992 >


The way prototypes are applied to subroutines is not consistent. I’m not sure how these cases should work:

sub foo {} # has a body already
sub foo ($);
print prototype \&foo;

That gives me a ‘Prototype mismatch’ warning and does not apply the prototype.

sub MODIFY_CODE_ATTRIBUTES{}
sub foo {} # has a body already
sub foo ($) :Frigid;
print prototype \&foo;

That gives me a ‘Prototype mismatch’ warning, but *does* apply the prototype. (In 5.10 it does not apply it.)

So now I’ve discovered a new feature!

Also, this case does apply the prototype, but that’s to be expected, as the sub is not defined:

sub foo($);
sub foo(;$); # warning, but the prototype is applied anyway
print prototype \&foo;

But in this case, the prototype is not applied:

sub bar($);
BEGIN { *foo = \&bar }
sub foo(;$); # warns
print prototype \&foo;

And here the prototype is silently ignored:

BEGIN { *foo = \&bar }
sub foo($);
print prototype \&foo;

---
Flags:
    category=core
    severity=low
---
Site configuration information for perl 5.14.0:

Configured by sprout at Wed May 11 13:45:58 PDT 2011.

Summary of my perl5 (revision 5 version 14 subversion 0) configuration:
  Snapshot of: eb70bb4a400e88a66c7e10414a2d52b5da4cfd1f
  Platform:
    osname=darwin, osvers=10.5.0, archname=darwin-thread-multi-2level
    uname='darwin pint.local 10.5.0 darwin kernel version 10.5.0: fri nov 5 23:20:39 pdt 2010; root:xnu-1504.9.17~1release_i386 i386 '
    config_args='-Dusedevel -de -Duseithreads -Doptimize=-g'
    hint=recommended, useposix=true, d_sigaction=define
    useithreads=define, usemultiplicity=define
    useperlio=define, d_sfio=undef, uselargefiles=define, usesocks=undef
    use64bitint=undef, use64bitall=undef, uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='cc', ccflags ='-fno-common -DPERL_DARWIN -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include',
    optimize='-g',
    cppflags='-fno-common -DPERL_DARWIN -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include'
    ccversion='', gccversion='4.2.1 (Apple Inc. build 5664)', gccosandvers=''
    intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=16
    ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=8
    alignbytes=8, prototype=define
  Linker and Libraries:
    ld='env MACOSX_DEPLOYMENT_TARGET=10.3 cc', ldflags =' -fstack-protector -L/usr/local/lib'
    libpth=/usr/local/lib /usr/lib
    libs=-ldbm -ldl -lm -lutil -lc
    perllibs=-ldl -lm -lutil -lc
    libc=/usr/lib/libc.dylib, so=dylib, useshrplib=false, libperl=libperl.a
    gnulibc_version=''
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=bundle, d_dlsymun=undef, ccdlflags=' '
    cccdlflags=' ', lddlflags=' -bundle -undefined dynamic_lookup -L/usr/local/lib -fstack-protector'

Locally applied patches:
    RC3

---
@INC for perl 5.14.0:
    /usr/local/lib/perl5/site_perl/5.14.0/darwin-thread-multi-2level
    /usr/local/lib/perl5/site_perl/5.14.0
    /usr/local/lib/perl5/5.14.0/darwin-thread-multi-2level
    /usr/local/lib/perl5/5.14.0
    /usr/local/lib/perl5/site_perl
    .

---
Environment for perl 5.14.0:
    DYLD_LIBRARY_PATH (unset)
    HOME=/Users/sprout
    LANG=en_US.UTF-8
    LANGUAGE (unset)
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/X11/bin:/usr/local/bin
    PERL_BADLANG (unset)
    SHELL=/bin/bash




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