GNU bug report logs - #6538
Removal of C_DEBUG_SWITCH changes CFLAGS

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Message #3 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Glenn Morris <rgm <at> gnu.org>
To: submit <at> debbugs.gnu.org
Subject: Removal of C_DEBUG_SWITCH changes CFLAGS
Date: Tue, 29 Jun 2010 23:00:09 -0400

Package: emacs

Configuring Emacs 23.2 on Solaris 2.10 with a non-GNU cc, one gets
generated Makefiles containing:

CFLAGS=-g -O 

Configuring the current trunk, one gets

CFLAGS=

The cause appears to be the removal of C_DEBUG_SWITCH.

It is possible other platforms are affected, I did not check (likewise
with LIBS_DEBUG).


The configure logic (faithfully inherited from cpp) is weird. Eg
C_OPTIMIZE_SWITCH goes unused with non-GNU compilers.

Message #8 received at 6538-done <at> debbugs.gnu.org (full text, mbox):

From: Dan Nicolaescu <dann <at> gnu.org>
To: Glenn Morris <rgm <at> gnu.org>
Cc: 6538-done <at> debbugs.gnu.org
Subject: Re: bug#6538: Removal of C_DEBUG_SWITCH changes CFLAGS
Date: Wed, 30 Jun 2010 01:56:47 -0400

Glenn Morris <rgm <at> gnu.org> writes:

> Package: emacs
>
> Configuring Emacs 23.2 on Solaris 2.10 with a non-GNU cc, one gets
> generated Makefiles containing:
>
> CFLAGS=-g -O 
>
> Configuring the current trunk, one gets
>
> CFLAGS=
>
> The cause appears to be the removal of C_DEBUG_SWITCH.

> It is possible other platforms are affected, I did not check (likewise
> with LIBS_DEBUG).

LIBS_DEBUG was just -lg, it can be safely ignored.

>
> The configure logic (faithfully inherited from cpp) is weird. Eg
> C_OPTIMIZE_SWITCH goes unused with non-GNU compilers.

Not anymore.  
C_DEBUG_SWITCH was weird, it used to specify optimization flags too,
that's probably why C_OPTIMIZE_SWITCH is unused.
C_DEBUG_SWITCH was just -g -O for all platforms that bothered to set it.  
We get that anyway for non-GCC compilers.

Message #11 received at 6538 <at> debbugs.gnu.org (full text, mbox):

From: Glenn Morris <rgm <at> gnu.org>
To: Dan Nicolaescu <dann <at> gnu.org>
Cc: 6538 <at> debbugs.gnu.org
Subject: Re: bug#6538: Removal of C_DEBUG_SWITCH changes CFLAGS
Date: Wed, 30 Jun 2010 02:37:14 -0400

Dan Nicolaescu wrote:

> C_DEBUG_SWITCH was weird, it used to specify optimization flags too,
> that's probably why C_OPTIMIZE_SWITCH is unused.

Yes, it was all very weird...

> C_DEBUG_SWITCH was just -g -O for all platforms that bothered to set it.  

What about irix6-5: "-g3 -O -OPT:Olimit=3500".

> We get that anyway for non-GCC compilers.

I noticed that AC_PROG_CC tests for -g, and adds it to CFLAGS if
supported. It also adds -O2 when using gcc. Perhaps this could be used
to further simplify configure.in...

Message #14 received at 6538 <at> debbugs.gnu.org (full text, mbox):

From: Dan Nicolaescu <dann <at> gnu.org>
To: Glenn Morris <rgm <at> gnu.org>
Cc: 6538 <at> debbugs.gnu.org
Subject: Re: bug#6538: Removal of C_DEBUG_SWITCH changes CFLAGS
Date: Wed, 30 Jun 2010 03:27:51 -0400

Glenn Morris <rgm <at> gnu.org> writes:

> Dan Nicolaescu wrote:
>
>> C_DEBUG_SWITCH was just -g -O for all platforms that bothered to set it.  
>
> What about irix6-5: "-g3 -O -OPT:Olimit=3500".

IMO it's not worth the complication.

>> We get that anyway for non-GCC compilers.
>
> I noticed that AC_PROG_CC tests for -g, and adds it to CFLAGS if
> supported. It also adds -O2 when using gcc. Perhaps this could be used
> to further simplify configure.in...

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