Re: Using --enable-debug and defining a macro from it...?

[Matthew Woehlke]

Braden McDaniel wrote:
> Matthew Woehlke wrote:
> > (If this isn't the place for 'how do I...?' questions, please 
> > re-direct me, but I do see it isn't the -bugs list.)
> >
> > First off, I have a very skeleton configure.in (see below). How do I add 
>
> The name "configure.ac" is preferred for autoconf >= 2.5x.

Eh, well blame KDevelop. :-) Say, can I borrow some of you to beat them 
(KDE) over the head with their various anachronisms? ;-)

> > '--enable-debug' to this? (I see AC_ARG_ENABLE, but is there not a 
> > standard one for debug? I can't find one, but it seems to be a standard.)
>
> There isn't and it's not. AC_ARG_ENABLE is what you would use for such 
> an option.

Hmm, ok KDE must have one buried somewhere. I'll make one up; thanks!

> Unless you have some unusual debugging requirements, I find that it's 
> generally simpler to apply debugging-related options via the CPPFLAGS, 
> CFLAGS, and CXXFLAGS user variables at configure time. Many useful 
> debugging options will be compiler-specific.

Well, KDevelop wants to use '--enable-debug=full', although I will 
probably change this. Mostly because of the second question; I want to 
combine CXXFLAGS tweaking with tinkering with adding a define to turn on 
internal debugging. (Actually I guess I could do this via CXXFLAGS too, 
but... well, since I still don't get AC_DEFINE, I guess I will just use 
CXXFLAGS.)

Hmm, apparently KDE's acinclude.m4 is floating around all over the place 
(and I mean outside of KDE).

> > Second, I want to add a define to config.h based on the value of 
> > --enable-debug. How do I do this?
>
> You use AC_DEFINE to specify preprocessor definitions that will appear 
> in your config header. Note that the config header is not intended to be 
> installed; as such, using it to toggle things that impact your ABI is 
> typically unwise.

Don't worry, I'm not... I'm using it to toggle if debugging output is 
produced.

> > ====
> > AC_INIT(<...>)
> >
> > AM_CONFIG_HEADER(config.h)
> > AM_INIT_AUTOMAKE(<pkg>, 0.1)
>
> Refer to the documention for a (at least somewhat) recent version of 
> automake for the preferred form of AM_INIT_AUTOMAKE invocation.

I'll assume you meant "AM_INIT_AUTOMAKE" (no args).

> > AC_LANG_CPLUSPLUS
>
> This is unnecessary.

See my first comment. :-)

> > AC_PROG_CC
> > AC_PROG_CXX
> > AC_PROG_RANLIB
> > AC_PROG_INSTALL
> >
> > AC_OUTPUT(Makefile src/Makefile <...>)
>
> The preferred way to do this with modern autoconf is to use 
> AC_CONFIG_FILES and invoke AC_OUTPUT with no arguments.

Thanks. Again, see my first comment. Ack, and I can't change this, 
KDevelop updates it automatically and will probably be confused if I do.

--
Matthew
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> PRAISE HIPPOS
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