On Wed, Jan 25, 2023 at 9:37 AM Ben Greear <[email protected]> wrote: > > On 1/25/23 3:51 AM, Jeffrey Walton wrote: > > On Wed, Jan 25, 2023 at 12:46 AM Ben Greear via curl-library > > <[email protected]> wrote: > >> > >> So, I'm well off in the weeds here. > >> > >> Trying to compile lib-cares on macos (using clang), for ARM target on > >> x86-64 macos machine. I'm able to see the > >> c files compiled for the right target, but the linker part is not passing > >> the -target > >> flag it seems. > >> > >> [...] > >> Here is how I am doing the configure step: > >> > >> (cd c-ares.ct && \ > >> export CFLAGS="-mmacosx-version-min=11.0 -target > >> arm64-apple-macos11"; \ > >> export LDFLAGS="-mmacosx-version-min=11.0 -target > >> arm64-apple-macos11"; \ > >> ./configure --enable-warnings --host=aarch64-apple-darwin && \ > >> perl -i.bkp -pe 's/^archive_cmds.*\K-install_name/-target > >> arm64-apple-macos11 -install_name/' libtool) > > > > I think there may be two problems. First, I think you should set a > > sysroot. Second, I think you should set CPPFLAGS. I would also set > > CXXFLAGS for completeness, but I don't believe it's a problem in this > > instance. CXXFLAGS will just be ignored if it is not used. > > > > CPPFLAGS will include --isysroot . LDFLAGS will include --sysroot. > > > > Here's what things look like when I set a cross-compile environment > > for an iPad from an old Intel MacBook using an old XCode: > > Thanks for the suggestion. I'm pretty sure it is not a problem with setting > C*FLAGS, > since those show up as expected in sysroot. I think '-target' is treated > special > somehow and ignored, though I cannot find exactly why/where that is happening. > > Even after my hack yesterday I found another problem though, and that is the > libraries > like 'openssl' that I was getting from 'mac ports' project > are of course built for the host CPU so won't link into the m1 compiled code.
Yeah, you usually need to build the target (like cURL and c-ares) and all the dependencies (like IDN2, PCRE and OpenSSL) in this scenario. It has been my experience that cuRL is one of the tougher recipes you will encounter because it has so many dependendencies. It's not good or bad, it's just the way it is. > Do you know if there is an easy way to install ports for a non-native CPU? > I'm guessing not, and that > my best way forward is just to buy another m1 macos machine and build > directly on it. > But, if you know a way, please let me know. Native compilation will probably be easiest. If you want to cross-compile, then you will want (need?) a script like setenv-ios.sh to setup all your flags. Decide on a location, like /opt/ios/aarch64/. Then, for cURL, c-ares and each dependent library, you configure for the cross-compile (using --host and --build), and build each library for the common place (--prefix=/opt/ios/aarch64/). Your flags will need to include /opt/ios/aarch64/include in CPPFLAGS, and /opt/ios/aarch64/lib for LDFLAGS. The pain point of the cross-compile will be projects which do not honor your flags. The makefile authors will overwrite your CPPFLAGS, CFLAGS, CXXFLAGS and LDFLAGS, and it will break your cross-compile. I have patched a lot of makefiles over the years because of this problem. A good program to experiment with cross-compiles is OpenSSH. OpenSSH has two components - OpenSSH itself and OpenSSL as a dependency. (LDNS is optional and not required). Once you work out your methodology with OpenSSH, it will scale to bigger projects like cURL (modulo makefile authors stomping on your flags). Jeff -- Unsubscribe: https://lists.haxx.se/listinfo/curl-library Etiquette: https://curl.se/mail/etiquette.html
