Hi Paul, > On 25 Nov 2022, at 20:13, Andrew Pinski via Gcc <gcc@gcc.gnu.org> wrote: > > On Fri, Nov 25, 2022 at 12:08 PM Paul Koning <paulkon...@comcast.net> wrote: >> >>> On Nov 25, 2022, at 3:03 PM, Andrew Pinski <pins...@gmail.com> wrote: >>> >>> On Fri, Nov 25, 2022 at 11:59 AM Paul Koning via Gcc <gcc@gcc.gnu.org> >>> wrote: >>>> >>>> I'm trying to use fairly recent GCC sources (the gcc-darwin branch to be >>>> precise) to build Ada, starting with the latest (2020) release of Gnat >>>> from Adacore. >>> >>> Are you building a cross compiler or a native compiler? >>> If you are building a cross, you need to bootstrap a native compiler first. >> >> I'm not sure. The installed Gnat is x86_64-darwin; I want to build >> aarch64-darwin. > > You have to build a x86_64-darwin compiler first with the same sources > as you are building for aarch64-darwin.
So .. 1/ if you are on arm64 Darwin, - the first step is to bootstrap the compiler using Rosetta 2 and the available x86_64 gnat. 2/ if you are on x86_64 Darwin… - the first step is to bootstrap the compiler using the available x86-64 gnat. then... - then you can build a cross to aarch64 using that just-build compiler. - then you can do a native cross (target==host!=build) using that, which will give you a usable native compiler for arm64 .. (2 is what I was doing all the way through the development - until I recently got an arm64 machine).. I know that Rosetta 2 bootstrap worked a few days ago … BTW: the final step “native cross” can be a bit tricky in terms of configure line - since some configure steps cannot (in general) run the tools on the “foreign” host - so that you might need to specify the linker version (we don’t have the option to do —with-ld64=NN.MM yet, but there is code that cares about the version of ld64.. so) >> But in any case, how does that relate to the error messages I got? They >> don't seem to have anything to do with missing compilers, but rather with >> the use of language features too new for the available (downloadable) Gnat. > > From https://gcc.gnu.org/install/prerequisites.html: > "In order to build a cross compiler, it is strongly recommended to > install the new compiler as native first, and then use it to build the > cross compiler. Other native compiler versions may work but this is > not guaranteed and *****will typically fail with hard to understand > compilation errors during the build.****" > > I added the emphasis but yes this is all documented correctly. thanks for the reminder! cheers Iain
