rust-native failed with ~200 errors inside the HOST's own glibc and
libstdc++ headers while compiling rustc_llvm's llvm-wrapper/*.cpp for
x86_64-unknown-linux-gnu.
rustc_llvm's build script passes `llvm-config --includedir` straight to
the host c++. The redoxer toolchain's include/ is a MIXED directory,
holding relibc's TARGET headers (stdlib.h, features.h, fenv.h, ...)
beside the llvm/ and clang/ ones, so relibc's features.h shadowed
glibc's, __GLIBC_PREREQ was never defined, and every host header testing
it failed:
/usr/include/c++/16/x86_64-pc-linux-gnu/bits/os_defines.h:44:19:
error: missing binary operator before token '('
Reproducible in three lines with no rustc involved:
printf '#include <cstdlib>\nint main(){}' > t.cpp
c++ -std=c++17 -I${HOME}/.redoxer/x86_64-unknown-redox/toolchain/include -c t.cpp
This is the same leak recorded as gcc-native's stopping point in
local/docs/NATIVE-TOOLCHAIN-WORKSTREAM.md -- one root cause, both
recipes -- though in the opposite direction to what that note assumed:
target headers reaching a host compile, not the reverse.
Fixed with host:llvm-native (+ .dev/.runtime). Host deps stage into
COOKBOOK_TOOLCHAIN, a tree SEPARATE from the target sysroot, so the
GNU/Linux libLLVM.so.21.1 cannot collide with the Redox one llvm21
stages -- the collision this recipe's llvm21 comment already records.
Its include tree holds only llvm/, llvm-c/, clang/, clang-c/, lld/. An
unset COOKBOOK_TOOLCHAIN is now a hard error rather than a silent
fallback to the polluted path.
Second defect, exposed by the first fix: DYNAMIC_INIT exports
CXXFLAGS=-fno-hardened for the GCC 16 cross compiler, and the unset list
dropped CC/CXX/LDFLAGS but not CFLAGS/CXXFLAGS/CPPFLAGS. cc-rs falls
back to the generic CXXFLAGS when the target-specific one is empty and
handed it to the host c++, which now resolves through
COOKBOOK_TOOLCHAIN/bin to llvm-native's clang++:
rustc_llvm@0.0.0: c++: error: unknown argument: '-fno-hardened'
A pre-existing leak: the cross recipes/dev/rust carries the same unset
list and never hit it only because nothing puts a clang on its PATH.
llvm-native's own recipe already unsets these three for this reason.
Target-side compilation is unaffected: config.toml pins cc/cxx/ar/linker
for the Redox triple, and the target RUSTFLAGS are captured into
CARGO_TARGET_<ARCH>_UNKNOWN_REDOX_RUSTFLAGS before the unset.
Also carries earlier uncommitted working-tree changes to this recipe
that the build depends on: the explicit relibc dependency, the
llvm-native -> llvm21 switch for the Redox-hosted rustc, and the
COOKBOOK_HOST_SYSROOT assignment, plus deny-warnings = false in
config.toml.
Verified: rustc, cargo, rustdoc, rustfmt, clippy-driver and
librustc_driver-*.so stage as Redox binaries -- ELF interpreter
/lib/ld64.so.1, OS/ABI System V, NEEDED libc.so.6 from relibc.
vasilito
75a33e0430