Re: if vs. ifdef in Makefile.am

[Bogdan]

ljh via Discussion list for automake <automake@gnu.org>, Wed Mar 01 
2023 19:50:56 GMT+0100 (Central European Standard Time)
> Hi community,
>
>
> I want to build debug or release with&nbsp;
>
>
> ```
> $ make # NDEBUG=1
> $ make NDEBUG=1
> ```
>
>
> Can I have automake.am to define and convey something like this to the output 
> Makefile:
>
>
> ```
> ifdef NDEBUG &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; # if vs. ifdef
> CPPFLAGS += -DNDEBUG
> CFLAGS += -O3 # .cpp
> else
> CFLAGS += -g # .cpp
> LDFLAGS += -fsanitize=address
> endif
> ```
>
>
> But it seems I can only write `if` but not `ifdef` in Makefile.am.
>
>
> So I had to enable ndebug option in configure.ac. That's a lot more work.
>
>
>
> Thanks


Hi.

 Just adding my 2 cents...
 I hope I won't be saying something silly or obvious here, but maybe 
you can pass the actual flags on the command line as a new variable 
and include it *unconditionally* in the Makefile.am (expanding to 
empty if not defined).
 Sure, that's more troublesome, but at least you can have this 
working even now, I guess.

# Makefile.am:
AM_CPPFLAGS = ... $(MY_CPPFLAGS) ...
AM_CFLAGS = ... $(MY_CFLAGS) ...
AM_LDFLAGS = ... $(MY_LDFLAGS) ...

A single 'autoreconf'/'automake' invocation later and you can do:

# release build:
make MY_CFLAGS=-g MY_LDFLAGS=-fsanitize=address

# debug build:
make MY_CFLAGS=-O3 MY_CPPFLAGS=-DNDEBUG

 Probably Nick's suggestion (a new option to ./configure or the 
AC_HEADER_ASSERT macro) would be the most future-proof, but it 
requires running ./configure each time you wish to change the build 
type (which maybe is not a bad idea, it depends).

--
Regards - Bogdan ('bogdro') D.                 (GNU/Linux & FreeDOS)
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