Setting -g3 is not trivial

[p5pRT]

Migrated from rt.perl.org#112536 (status was 'open')

Searchable as RT112536$

[p5pRT]

From @ruz

Created by ruz@new-mac.local

Wanted to compile perl with -g3 flag to enable macros expanding
in GDB. According to INSTALL document​:

  =item -DEBUGGING=-g

  =item -Doptimize=-g

  Adds -g to optimize, but does not set -DDEBUGGING.

  (Note​: Your system may actually require something like cc -g2.
  Check your man pages for cc(1) and also any hint file for your system.)

This note made me believe that I can set -DEBUGGING=-g3 and it will work,
but it failed. I've tried a combinations using -Accflags and -DDEBUGGING.
It was a mess. Ended up looking into Configure script to figure it out.

Final variant that worked for me​:

  -Doptimize='-O3 -g3' -DEBUGGING

So it has two disadvantages​: 1) you have to know or struggle 2) have to
repeat default value (-O3).

Perl Info

Flags:
    category=install
    severity=low

Site configuration information for perl 5.15.9:

Configured by ruz at Thu Apr 19 13:44:09 GET 2012.

Summary of my perl5 (revision 5 version 15 subversion 9) configuration:
  Local Commit: 72fe21782afa1cae1beef02d6a0216ed4c9c5e6a
  Ancestor: 1a15d16d8ab308fc4f99063c180391a513f81fdb
  Platform:
    osname=darwin, osvers=10.8.0, archname=darwin-thread-multi-2level
    uname='darwin new-mac.local 10.8.0 darwin kernel version 10.8.0:
tue jun 7 16:33:36 pdt 2011; root:xnu-1504.15.3~1release_i386 i386
i386 macbook7,1 darwin '
    config_args='-des -Dprefix=/Users/ruz/perl/blead -Dusedevel
-Doptimize=-O3 -g3 -DEBUGGING -Dusemymalloc -Dusethreads
-Dinc_version_list=none'
    hint=recommended, useposix=true, d_sigaction=define
    useithreads=define, usemultiplicity=define
    useperlio=define, d_sfio=undef, uselargefiles=define, usesocks=undef
    use64bitint=define, use64bitall=define, uselongdouble=undef
    usemymalloc=y, bincompat5005=undef
  Compiler:
    cc='cc', ccflags ='-fno-common -DPERL_DARWIN -DDEBUGGING
-fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include
-I/opt/local/include',
    optimize='-O3 -g3',
    cppflags='-fno-common -DPERL_DARWIN -DDEBUGGING
-fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include
-I/opt/local/include'
    ccversion='', gccversion='4.2.1 (Gentoo 4.2.1_p5666, Apple Inc.
build 5666) (dot 3)', gccosandvers=''
    intsize=4, longsize=8, ptrsize=8, doublesize=8, byteorder=12345678
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=16
    ivtype='long', ivsize=8, 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 -L/opt/local/lib'
    libpth=/usr/local/lib /opt/local/lib /usr/lib
    libs=-lgdbm -ldbm -ldl -lm -lutil -lc
    perllibs=-ldl -lm -lutil -lc
    libc=, 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 -L/opt/local/lib -fstack-protector'

Locally applied patches:



@INC for perl 5.15.9:
    /Users/ruz/perl/blead/lib/site_perl/5.15.9/darwin-thread-multi-2level
    /Users/ruz/perl/blead/lib/site_perl/5.15.9
    /Users/ruz/perl/blead/lib/5.15.9/darwin-thread-multi-2level
    /Users/ruz/perl/blead/lib/5.15.9
    .


Environment for perl 5.15.9:
    DYLD_LIBRARY_PATH=/opt/oracle/instantclient_10_2_64bit/:
    HOME=/Users/ruz
    LANG=ru_RU.UTF-8
    LANGUAGE (unset)
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=/Users/ruz/bin:/opt/local/bin:/opt/local/sbin:/opt/portage/usr/sbin:/opt/portage/usr/bin:/opt/portage/sbin:/opt/portage/bin:/opt/portage/usr/local/bin/:/opt/portage/opt/bin:/opt/portage/usr/sbin:/opt/portage/sbin:/opt/portage/usr/x86_64-apple-darwin10/gcc-bin/4.2.1:/opt/local/usr/sbin:/opt/local/usr/bin:/opt/local/sbin:/opt/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/local/bin:/usr/X11/bin:/Users/ruz/.perl6/bin:/Users/ruz/projs/perl6/rakudo/install/bin
    PERL_BADLANG (unset)
    SHELL=/opt/portage/bin/bash

-- 
Best regards, Ruslan.

[p5pRT]

From @Tux

On Thu, 19 Apr 2012 03​:56​:35 -0700, Ruslan Zakirov (via RT)
<perlbug-followup@​perl.org> wrote​:

Wanted to compile perl with -g3 flag to enable macros expanding
in GDB. According to INSTALL document​:

=item \-DEBUGGING=\-g

=item \-Doptimize=\-g

Adds \-g to optimize\, but does not set \-DDEBUGGING\.

\(Note​:  Your system may actually require something like cc \-g2\.
Check your man pages for cc\(1\) and also any hint file for your system\.\)

This note made me believe that I can set -DEBUGGING=-g3 and it will work,
but it failed. I've tried a combinations using -Accflags and -DDEBUGGING.
It was a mess. Ended up looking into Configure script to figure it out.

I never thought of additional digits when allowing that. I could extend
the current behavior to do so if p5p thinks that is sane.

: Check what DEBUGGING is required from the command line
: -DEBUGGING or -DDEBUGGING or
: -DEBUGGING=both = -g + -DDEBUGGING
: -DEBUGGING=-g or -Doptimize=-g = -g
: -DEBUGGING=none or -UDEBUGGING =
: -DEBUGGING=old or -DEBUGGING=default = ? $optimize

Final variant that worked for me​:

\-Doptimize='\-O3 \-g3' \-DEBUGGING

So it has two disadvantages​: 1) you have to know or struggle 2) have to
repeat default value (-O3).

--
H.Merijn Brand http​://tux.nl Perl Monger http​://amsterdam.pm.org/
using perl5.00307 .. 5.14 porting perl5 on HP-UX, AIX, and openSUSE
http​://mirrors.develooper.com/hpux/ http​://www.test-smoke.org/
http​://qa.perl.org http​://www.goldmark.org/jeff/stupid-disclaimers/

[p5pRT]

The RT System itself - Status changed from 'new' to 'open'

[p5pRT]

From @Leont

On Sun, Apr 22, 2012 at 12​:05 PM, H.Merijn Brand <h.m.brand@​xs4all.nl> wrote​:

I never thought of additional digits when allowing that. I could extend
the current behavior to do so if p5p thinks that is sane.

If you do that, don't forget to allow -ggdb3 and similar too too.

Leon

[p5pRT]

From @nwc10

On Mon, Apr 23, 2012 at 01​:39​:49PM +0200, Leon Timmermans wrote​:

On Sun, Apr 22, 2012 at 12​:05 PM, H.Merijn Brand <h.m.brand@​xs4all.nl> wrote​:

I never thought of additional digits when allowing that. I could extend
the current behavior to do so if p5p thinks that is sane.

If you do that, don't forget to allow -ggdb3 and similar too too.

Seems sane to me. At least, I can't think of anything it might be confused
with.

Is there a "list" of "similar too"? Or do we assume that anything
/^-g[a-z0-9][-+a-z0-9]*$/ is valid?

(ie is there a counter-example of a compiler flag starting -g that isn't
about debugging, and would be confusing to add here)

Nicholas Clark

[p5pRT]

From ruz@bestpractical.com

On Tue, Apr 24, 2012 at 15​:22, Nicholas Clark <nick@​ccl4.org> wrote​:

On Mon, Apr 23, 2012 at 01​:39​:49PM +0200, Leon Timmermans wrote​:

On Sun, Apr 22, 2012 at 12​:05 PM, H.Merijn Brand <h.m.brand@​xs4all.nl> wrote​:

I never thought of additional digits when allowing that. I could extend
the current behavior to do so if p5p thinks that is sane.

If you do that, don't forget to allow -ggdb3 and similar too too.

Seems sane to me. At least, I can't think of anything it might be confused
with.

Is there a "list" of "similar too"? Or do we assume that anything
/^-g[a-z0-9][-+a-z0-9]*$/ is valid?

I don't think so, but as I recall it's possible that you need
-gdwarf-2 -g3. Also, primary problem with instructions in INSTALL is
that those doesn't cover all possible cases. I wanted to compile
variant with -DDEBUGGING set and -gLevel adjusted to get macros
expansion in GDB. Even if you extended -DDEBUGGING option with -gXXX
support then it's still open question on how to set -DDEBUGGING for
perl itself.

May be the following is better​:

-Aoptimize=-g3 -DEBUGGING

It probably works and you don't have to repeate -O3 flag in optimize.
If optimize option is properly described then there is no need in
-DEBUGGING=-g and =both variants. For backwards compatibility
-DDEBUGGING may add -g to optimize unless there -g* and -UDEBUGGING or
=none variant can delete all -g* flags from optimize.

(ie is there a counter-example of a compiler flag starting -g that isn't
about debugging, and would be confusing to add here)

Nicholas Clark

--
Best regards, Ruslan.