add -m64 CFLAGS when targeting mingw64, add -m32/-m64 to LDFLAGS

[vszakats]

No description provided.

[gvanem]

How can you be sure that this gcc can create dual targets (both -m32 and -m64). Are you assuming MingW-builds or Ruben's gcc-MingW-w64 here? Last time I tried them, they sucked. Only TDM-gcc works for dual-targeting IMHO.

[gknauf]

On 08.01.2015 20:17, Gisle Vanem wrote:

How can you be sure that this |gcc| can create dual targets (both |-m32|
and |-m64|). Are you assuming MingW-builds or Ruben's gcc-MingW-w64
here? Last time I tried them, they sucked. Only TDM-gcc works for
dual-targeting IMHO.
hmm, when I recently added the -m32 flag I've tested that various MinGW
32-bit versions accept it; also I use -m32 already for a long time with
my NetWare builds, and it didnt matter up to now if it was a 32-bit or
64-bit Linux gcc;
so I assume that at least gcc >= 3.2 does either understand or ignore
the -m32 flag; I've not yet tested if the same goes for the -m64 flag,
but if so it may be safe too to add it ...
what problems did you face?

Gün.

[vszakats]

Dual mingw-builds work fine with this switch, and as far as I know they are supported by single target 64-bit ones, too, so they are either ignored (when using a mingw that targets 64-bit by default anyway), or required (in dual target mingws when building to non-default target), or rejected when in disagreement with mingw capabilities (misconfiguration).

These are the mingw distro combinations I'm aware of:

1. 32-bit hosted, 32-bit target – -m64 rejected (ARCH setting should be corrected in this case)
2. 64-bit hosted, 64-bit target – -m64 ignored as the default
3. 32-bit hosted, dual target, defaulting to 32-bit – -m64 required if one wants a 64-bit target
4. 64-bit hosted, dual target, defaulting to 64-bit – -m64 ignored as the default

Above should be true for all mingw distros, what I actually made tests with lately, is this one: https://sourceforge.net/projects/mingw-w64/ (they didn't suck in my experience, and we had a fair share of suckage with all distros in various points of time - since some years, this one works well)

[vszakats]

[ To be precise the niXman builds worked well for us from https://sourceforge.net/projects/mingwbuilds/, and haven't tried Ruben's builds (these seem to be outdated now.) Recently the builds formerly known as niXman can be found at https://sourceforge.net/projects/mingw-w64/files/ under /Toolchains targetting Win[32|64]/Personal Builds/mingw-builds/. ]

[vszakats]

As for the -m32 added to LDFLAGS in line https://github.com/bagder/curl/pull/134/files#diff-cff6f4d0b937841a93595fb097eaeb12R98, it should be just as safe as the CFLAGS usage in the existing preceding line.

[gknauf]

On 08.01.2015 22:11, Viktor Szakáts wrote:

As for the |-m32| added to |LDFLAGS| in line
https://github.com/bagder/curl/pull/134/files#diff-cff6f4d0b937841a93595fb097eaeb12R98,
it should be just as safe as the |CFLAGS| usage in the existing previous
line.
I've just tested your patch, and see no issues with my MinGW and MinGW64
versions.

Daniel or Steve, can you please commit? I'm not (yet) familar with the
pull request stuff, and fear to not doing it properly :-P

Gün.

[vszakats]

Thanks for the tests Günter.