This patch switches the CoreFoundation on x86_64-darwin from the open
source swift-corelibs-foundation (CF) to the system CoreFoundation.
This change was motivated by failures building packages for the current
staging-next cycle #263535 due to an apparent incompatibility with the
rpath-based approach to choosing CF or CoreFoundation and macOS 14. This
error often manifests as a crash with an Illegal Instruction.
For example, building aws-sdk-cpp for building Nix will fail this way.
https://hydra.nixos.org/build/239459417/nixlog/1
Application Specific Information:
CF objects must have a non-zero isa
Error Formulating Crash Report:
PC register does not match crashing frame (0x0 vs 0x7FF8094DD640)
Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0 CoreFoundation 0x7ff8094dd640 CF_IS_OBJC.cold.1 + 14
1 CoreFoundation 0x7ff8094501d0 CF_IS_OBJC + 60
2 CoreFoundation 0x7ff8093155e8 CFRelease + 40
3 ??? 0x10c7a2c61 s_aws_secure_transport_ctx_destroy + 65
4 ??? 0x10c87ba32 aws_ref_count_release + 34
5 ??? 0x10c7b7adb aws_tls_connection_options_clean_up + 27
6 ??? 0x10c596db4 Aws::Crt::Io::TlsConnectionOptions::~TlsConnectionOptions() + 20
7 ??? 0x10c2d249c Aws::CleanupCrt() + 92
8 ??? 0x10c2d1ff0 Aws::ShutdownAPI(Aws::SDKOptions const&) + 64
9 ??? 0x102d9bc6f main + 335
10 dyld 0x202f333a6 start + 1942
According to a [post][1] on the Apple developer forums, hardening was
added to CoreFoundation, and this particular message occurs when you
attempt to release an object it does not recognize as a valid CF object.
(Thank you to @lilyinstarlight for finding this post).
When I switched aws-sdk-cpp to link against CoreFoundation instead of
CF, the error went away. Somehow both libraries were being used. To
prevent dependent packages from linking the wrong CoreFoundation, it
would need to be added as a propagated build input.
Note that there are other issues related to mixing CF and CoreFoundation
frameworks. #264503 fixes an issue with abseil-cpp where it propagates
CF, causing issues when using a different SDK version. Mixing versions
can also cause crashes with Python when a shared object is loaded that
is linked to the “wrong” CoreFoundation.
`NIX_COREFOUNDATION_RPATH` is supposed to make sure the right
CoreFoundation is being used, but it does not appear to be enough on
macOS 14 (presumably due to the hardening). While it is possible to
propagate CoreFoundation manually, the cleaner solution is to make it
the default. CF remains available as `darwin.swift-corelibs-foundation`.
[1]: https://developer.apple.com/forums/thread/739355
Deeply-curried functions are pretty error-prone in untyped languages
like Nix. This is a particularly bad case because
`top-level/splice.nix` *also* declares a makeScopeWithSplicing, but
it takes *two fewer arguments*.
Let's switch to attrset-passing form, to provide some minimal level
of sanity-checking.
cctools-llvm is a replacement for cctools that replaces as much of cctools with equivalents from LLVM that it can reasonably do. This was motivated by wanting to reduce dependencies on cctools, which are updated infrequently by upstream.
To provide a motivating example, the version of `strip` included in cctools cannot properly strip the archives in compiler-rt in LLVM 15. Paths are left to bootstrap tools, resulting in failed requisites checks in the final stdenv build. Since `strip` needs replaced, the opportunity was taken to replace other provided they are functional replacements.
Note: This has to be done in cctools (or some equivalent) because some derivations (noteably LLVM) use the bintools of the stdenv directly instead of going through the wrapper.
The following tools from LLVM are not used in this derivation:
* LLD - not fully compatible with ld64 yet and potentially too big of a change;
* libtool - not a drop-in replacement yet because it does not support linker passthrough, which is needed by xcbuild;
* lipo - crashes when running the LLVM test suite;
* install_name_tool - fails when trying to build swift-corefoundation; and.
* randlib - not completely a drop-in replacement, so leaving it out for now.
If other incompatabilities are found, the tools can be reverted or made conditional. For example, cctools `strip` is preferred on older versions of LLVM (which lack the compiler-rt issue) or when cctools itself is a new enough version because `llvm-strip` on LLVM 11 produces files that older verions of `codesign_allocate` cannot process correctly.
One final caveat/note: Some tools are not duplicated or linked from cctools-port. The names of the tools and which ones were linked was determined based on what is provided upstream in Xcode and is installed on macOS system.
For reasons explained in the commit contents, in order to build the
native gnat package for x86_64-darwin, the native gnatboot package for
x86_64-darwin must have access to both the Clang integrated assembler
and the cctools GNU assembler for that platform. This commit creates a
package with both of those assemblers that x86_64-darwin gnatboot can
then be wrapped with.
Co-authored-by: Sandro <sandro.jaeckel@gmail.com>
- Use the 11.0 SDK instead of the 10.12 one on x86_64-darwin;
- Use `NIX_CFLAGS_COMPILE` and `NIX_LDFLAGS` to pass flags to the
compiler instead of patching the Xcode project files; and
- Use xcbuild to build the project.
