Re: AC_TRY_CPP too strict? (Was: grep -E)

[Pavel Roskin]

Hello, Alexandre!

> > It remains an open question whether Autoconf should be so strict.
> 
> It must.  There are compilers that don't return a failure status when
> asked to #include a non-existent file.

I propose a new item to the TODO list (for after 2.50):

========
Check if the compiler returns a failure status when asked to #include a
non-existent file. If it does, don't check stderr from cpp, only check the
exit status.
========

There are hundreds things a compiler can complain about. An example that I
remember - the native compiler on HP-UX would warn that the code it
generates doesn't run on earlier processors.
 
If the compiler is "wary" and indicates missing includes by the exit
status its subtle warnings should be acceptable. If the compiler is
"careless" its warnings should be taken with care.

Also it is better for developers to show warnings while compiling the code
than to hide them into config.log

Regards,
Pavel Roskin