GMP 6.3.0: Failure building on MinGW (defaulting to ABI=64)

[Marc Glisse]

On Sun, 10 Dec 2023, Simon Sobisch wrote:

> $ ./config.guess && gcc --version && as --version

gcc -v file.c
gives more information about the assembler that is really used.

> gcc.exe (MinGW.org GCC Build-2) 9.2.0

gcc-9 is old. Isn't mingw.org abandoned? I thought everyone had moved to 
mingw-w64.org.

> using ABI="64"
>      CC="gcc"
>      CFLAGS="-Wno-attribute"

Specifying CFLAGS yourself is not a great idea, it prevents GMP from 
adding nice optimization flags. If you really want to pass -Wno-attribute, 
either put it in CPPFLAGS, or run configure once without CFLAGS to see 
what GMP wants to use, and add -Wno-attribute to that.

> This error seems to be related to changing the ABI after the initial 
> configure. Using "make distclean" fixes this.
>
> I therefore think that something like `AC_ARG_VAR([ABI], [Application Binary 
> Interface to use])` (maybe also reference 
> https://gmplib.org/manual/ABI-and-ISA in its description) should be added to 
> configure.ac to make that error on an ABI change and also adding this missing 
> piece to configure's help output.

You mean this?
https://gmplib.org/repo/gmp-6.3/file/tip/configure.ac#l455

I think it has been there for a while.

-- 
Marc Glisse