We need this stuff to be available in lib so make-derivation.nix can
access it to construct the Meson cross file.
This has a couple of other advantages:
- It makes Rust less special. Now figuring out what Rust calls a
platform is the same as figuring out what Linux or QEMU call it.
- We can unify the schema used to define Rust targets, and the schema
used to access those values later. Just like you can set "config"
or "system" in a platform definition, and then access those same
keys on the elaborated platform, you can now set "rustcTarget" in
your crossSystem, and then access "stdenv.hostPlatform.rustcTarget"
in your code.
"rustcTarget", "rustcTargetSpec", "cargoShortTarget", and
"cargoEnvVarTarget" have the "rustc" and "cargo" prefixes because
these are not exposed to code by the compiler, and are not
standardized. The arch/os/etc. variables are all named to match the
forms in the Rust target spec JSON.
The new rust.target-family only takes a list, since we don't need to
worry about backwards compatibility when that name is used.
The old APIs are all still functional with no warning for now, so that
it's possible for external code to use a single API on both 23.05 and
23.11. We can introduce the warnings once 23.05 is EOL, and make them
hard errors when 23.11 is EOL.
...to be displayed on search.nixos.org &c; this is the same notice as
included by conda-forge per agreement with nvidia; cf. comments in
https://github.com/NixOS/nixpkgs/pull/76233
darwin.cctools defaults to `llvm-strip` when the version of LLVM in the
stdenv is 12 or newer. This strip implementation does not support the
`-c` flag required by older versions of GCC. Use the cctools-port
version for compatibility when building older versions of GCC.
The x86_64-darwin build fails with the following symbol errors when
building gencondmd:
Undefined symbols for architecture x86_64:
"_ix86_excess_precision", referenced from:
___cxx_global_var_init.101 in gencondmd.o
"_ix86_fpmath", referenced from:
___cxx_global_var_init.101 in gencondmd.o
"_ix86_isa_flags", referenced from:
___cxx_global_var_init.101 in gencondmd.o
"_ix86_unsafe_math_optimizations", referenced from:
___cxx_global_var_init.101 in gencondmd.o
"_target_flags", referenced from:
___cxx_global_var_init.101 in gencondmd.o
This commit applies a workaround posted to the GCC BugZilla.
See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92061.
Darwin uses the clang integrated assembler, which does not support
`--gstabs`. While the `configure` script detects whether the assembler
supports it, Darwin passes `--gstabs` unconditionally. This patch is
backported to make the bootstrap only use it when supported.
Older versions of GCC use `-pipe` on Darwin due to compatibility
problems with older cctools assemblers. Darwin now uses the clang
integrated assembler. While it is possible to pipe input into it, the
wrapper used in nixpkgs is not set up for it.
Fixing the wrapper would cause all of Darwin to rebuild, which is not
desirable, so just disable `-pipe` in the bootstrap configuration. The
clang integrated assembler doesn’t have the bug anyway.
The libgcc configure script was middetecting aarch64-darwin and trying
to use a deployment target of 10.5, which is not valid for that
platform. The build was failing because the linker was looking for stubs
that don’t exist (neither as part of the source releases nor as part of
the official SDK from Apple).
Backporting the `config.host` check and `t-darwin-rpath` from GCC 12
allows GCC 11 to build again on aarch64-darwin.
According to Hydra, the last time GCC 4.8 successfully built on Darwin
was October 2014. It is possible to make the first stage build
successfully with clang, but the resulting GCC is not capable of reading
the Darwin SDK headers due to their use of `__can_include`.
It’s been broken for almost a decade, so just disable it.
