Re: AC_PROG_LEX issue when compiling with -Werror

[Paul Eggert]

On 7/14/22 03:03, Tobias Brunner wrote:
> how to handle -Werror when we explicitly want to fail our automated 
> builds based on warnings without affecting the tests in configure.  Is 
> there a proper way to do this with Autoconf?

The way Gnulib-using programs do it, is to not use -Werror when running 
./configure. Instead, use it when running 'make'. This makes sense, as 
./configure does all sorts of low-level stuff that C compilers might 
complain about incorrectly.

Commonly there's a 'make' macro WARN_CFLAGS that contains warning 
options like -Wall, and WERROR_CFLAGS that contains just -Werror, and 
then AM_CFLAGS (or CFLAGS or whatever) contains $(WARN_CFLAGS) 
$(WERROR_CFLAGS). This lets the builder type 'make WERROR_CFLAGS=' to 
ignore warning failures, if that's what's wanted.

See GNU Grep for an example of this.