Hi! This (and last week) I’ve spent my time polishing the LLVM\/Clang
\ncrossdev work. I have also created ebuilds for llvm-libc, libc-hdrgen
\nand also the SCUDO allocator. But I will probably bake SCUDO into the
\nllvm-libc ebuild instead actually.<\/p>\n
One thing I have also made is a cross eclass that handles cross
\ncompilation, instead of having the same logic copy-pasted in all
\nebuilds. To differentiate a “normal” crossdev package and LLVM\/Clang
\ncrossdev I decided to use “cross_llvm-${CTARGET}” as package category
\nname. This is necessary since you need some way to tell the ebuild about
\nusing LLVM for cross. My initial idea was to handle all this in the
\ncrossdev script, but crossdev ebuilds are self-contained, and you can do
\nsomething like “emerge cross_llvm-gentoo-linux-llvm\/llvm-libc” and it
\nwill do the right thing without running emerge from crossdev. Hence I
\nneed to handle cross compilation in the ebuilds themselves, using the
\neclass. Me and sam are not sure if a new eclass is the right thing to
\ndo but I will continue with it until I get some more thoughts as we can
\njust inline everything later without wasting any work.<\/p>\n
I feel pretty much done now except for baking SCUDO directly into the
\nllvm-libc ebuild. Actually it is very simple to do but I got some issues
\nwith libstdc++ when using llvm\/ as root source directory for the libc
\nbuild, which is necessary to use when compiling SCUDO. Previously I used
\nruntimes\/ as root directory, and that worked without issue. Currently to
\nwork around this you can just compile the source files in
\nllvm-project\/compiler-rt\/lib\/scudo\/standalone and append the object
\nfiles into libc.a. LLVM libc then just works with crossdev and you
\ncan compile things with the emerge wrapper as usual, but currently a lot
\nof autotools things break due to me not having specified gnuconfig for
\nllvm-libc yet.<\/p>\n
I had a lot of trouble last week with sonames when doing an aarch64 musl
\ncrossdev setup and running binaries with qemu-user, however it turned
\nout it was just a warning and it worked after setting LD_LIBRARY_PATH as
\nenvvar to qemu-user. I spent a loong time on this.<\/p>\n
Currently I will need to upstream changes to compiler-rt ebuild, musl
\nllvm-libc ebuild, libc-hdrgen, cross.eclass, and of course crossdev.<\/p>\n
Next week I will send the changes upstream for review and continue work
\non LLVM libc, most likely simple packages like ed, and then try to get
\nthe missing pieces upstreamed to LLVM libc. fileno() is definitely
\nneeded for ed.<\/p>\n
Last week I did not write a blog post as I was in “bug hell” and worked
\non a lot of small things at once and thought “if I just finish this I
\ncan write a good report”, and then wednesday came, and I decided to just
\ndo an overview of all my work for this weeks’ blog instead \ud83d\ude00<\/p>\n
– —
\ncatcream<\/p>\n","protected":false},"excerpt":{"rendered":"
Hi! This (and last week) I’ve spent my time polishing the LLVM\/Clang crossdev work. I have also created ebuilds for llvm-libc, libc-hdrgen and also the SCUDO allocator. But I will probably bake SCUDO into the llvm-libc ebuild instead actually. One … Continue reading