gdb 11.1: configure doesn't check for gmp existence

gdb 11.1: configure doesn't check for gmp existence

[Andrea Monaco]

Hello,

gdb 11.1 depends on the gmp library, as docs also confirm.  But
./configure completes with success on my GNU/Hurd system even if the
library is not present, and then make aborts.  I think that configure
should fail if a strict dependency is missing.


Andrea Monaco

Re: gdb 11.1: configure doesn't check for gmp existence

[Simon Marchi]

On 2021-11-01 11:58 a.m., Andrea Monaco via Gdb wrote:
> 
> Hello,
> 
> gdb 11.1 depends on the gmp library, as docs also confirm.  But
> ./configure completes with success on my GNU/Hurd system even if the
> library is not present, and then make aborts.  I think that configure
> should fail if a strict dependency is missing.
> 
> 
> Andrea Monaco
> 

Can you show the error you get?  Normally, when you type "make" at the
top-level that will run the configure script in the gdb directory, and
that's when it should fail.  If that's what you get, then this is expected
(with how the build system currently works).

Simon

Re: gdb 11.1: configure doesn't check for gmp existence

[Andrea Monaco]

  > Can you show the error you get?  Normally, when you type "make" at
  > the top-level that will run the configure script in the gdb
  > directory, and that's when it should fail.

Upon check, yes, that's what happens.  But it's an unusual build system:
it's common to have Makefiles in subdirectories, while multiple
configures are less common.

Anyway, if gmp is an essential dependency, why does the top-level
configure complete without it?



Andrea Monaco

Re: gdb 11.1: configure doesn't check for gmp existence

[Rainer Orth]

Hi Andrea,

>   > Can you show the error you get?  Normally, when you type "make" at
>   > the top-level that will run the configure script in the gdb
>   > directory, and that's when it should fail.
>
> Upon check, yes, that's what happens.  But it's an unusual build system:
> it's common to have Makefiles in subdirectories, while multiple
> configures are less common.
>
> Anyway, if gmp is an essential dependency, why does the top-level
> configure complete without it?

it's also unlike GCC's gmp (and mpfr and mpc) detection which is done at
the toplevel and errors out if one of the necessary components is either
missing or too old.  Not only does GDB use a different way of detecting
support libraries, but also a less capable one than GCC's (cf. PR
build/28332 for a regression caused by that).  It's also confusing to
users familiar with GCC's configure options for gmp etc. location: they
are present but have no effect.  Not the best user experience, I'd
argue.

	Rainer

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Rainer Orth, Center for Biotechnology, Bielefeld University