since https://github.com/NixOS/nixpkgs/pull/292043 libcxxabi is built
using the same compiler wrapper as libcxx and thus uses the
`-rtlib=compiler-rt`. Adding the `LIBCXXABI_USE_COMPILER_RT=ON` at build
time ensures that the compiler-rt libraries provided at link time
resolving symbol errors for aarch64 pkgLLVM.libcxx build
https://hydra.nixos.org/build/253162977
The nixpkgs-unstable channel's programs.sqlite was used to identify
packages producing exactly one binary, and these automatically added
to their package definitions wherever possible.
- merge libcxxabi into libcxx for LLVM 12, 13, 14, 15, 16, 17, and git.
- remove the link time workaround `-lc++ -lc++abi` from 58 packages as it is no longer required.
- fixes https://github.com/NixOS/nixpkgs/issues/166205
- provides alternative fixes for. https://github.com/NixOS/nixpkgs/issues/269548https://github.com/NixOS/nix/issues/9640
- pkgsCross.x86_64-freebsd builds work again
This change can be represented in 3 stages
1. merge libcxxabi into libcxx -- files: pkgs/development/compilers/llvm/[12, git]/{libcxx, libcxxabi}
2. update stdenv to account for merge -- files: stdenv.{adapters, cc.wrapper, darwin}
3. remove all references to libcxxabi outside of llvm (about 58 packages modified)
### merging libcxxabi into libcxx
- take the union of the libcxxabi and libcxx cmake flags
- eliminate the libcxx-headers-only package - it was only needed to break libcxx <-> libcxxabi circular dependency
- libcxx.cxxabi is removed. external cxxabi (freebsd) will symlink headers / libs into libcxx.
- darwin will re-export the libcxxabi symbols into libcxx so linking `-lc++` is sufficient.
- linux/freebsd `libc++.so` is a linker script `LINK(libc++.so.1, -lc++abi)` making `-lc++` sufficient.
- libcxx/default.nix [12, 17] are identical except for patches and `LIBCXX_ADDITIONAL_LIBRARIES` (only used in 16+)
- git/libcxx/defaul.nix does not link with -nostdlib when useLLVM is true so flag is removed. this is not much different than before as libcxxabi used -nostdlib where libcxx did not, so libc was linked in anyway.
### stdenv changes
- darwin bootstrap, remove references to libcxxabi and cxxabi
- cc-wrapper: remove c++ link workaround when libcxx.cxxabi doesn't exist (still exists for LLVM pre 12)
- adapter: update overrideLibcxx to account for a pkgs.stdenv that only has libcxx
### 58 package updates
- remove `NIX_LDFLAGS = "-l${stdenv.cc.libcxx.cxxabi.libName}` as no longer needed
- swift, nodejs_v8 remove libcxxabi references in the clang override
https://github.com/NixOS/nixpkgs/pull/292043
This test fails in the presence of anti-virus software or other
intrusion-detection software that modifies the atime when run.
See nixos/nixpkgs#284056 and llvm/llvm-project#82372.
this allows a compiler derivation to provide a
hardeningUnsupportedFlagsByTargetPlatform passthru attr
that will be called with the targetPlatform to determine
the unsupported hardening flags for that platform.
we can do this because even though a clang compiler is
multi-target by nature, cc-wrapper effectively fixes the
target platform at wrapping time. otherwise we'd have to
sniff the intended target at runtime, which wouldn't
be fun at all.
the advantage of using a new attribute instead of
allowing hardeningUnsupportedFlags to optionally be a
function is that hardeningUnsupportedFlags retains its
simple overriding pattern for simple cases (i.e.
`(prev.hardeningUnsupportedFlags or []) ++ [ "foo" ]`
) which will continue to work as long as the bottom-most
function of hardeningUnsupportedFlagsByTargetPlatform
falls back to hardeningUnsupportedFlags.
c33c7c3d5f ("clang_11: Fix RISC-V builds for compiler-rt. (#135718)")
already marked tihs as broken for LLVM 11, but didn't apply the same
change to other affected LLVM versions.
This change applies the upstream PR
https://github.com/llvm/llvm-project/pull/77218 so the same link flags
on darwin are used as when LIBCXX_CXX_ABI=libcxxabi. Specifically, this
adds
"-Wl,-force_symbols_not_weak_list,${CMAKE_CURRENT_SOURCE_DIR}/../lib/notweak.exp"
which prevents libcxx from segfaulting on darwin
compiler-rt includes <linux/unistd.h> on RISC-V. This only seems to
be necessary for useLLVM, but looking at the source code I can't
see any reason for that, so probably in the non-useLLVM case it just
gets propagated in.
