Since a356782426f5bf54a00570e1f925345e5fda7b2e in llvm-project,
OpenMP can be built for mingw/aarch64, since
fb947c358661b3bd3d5e1fa776ec74cc0f308854 it should work correctly
in all currently tested cases, and since
97958c9bb83cec44b6ce13e732b53de0171a5d43 it can be built for
mingw/armv7.
Curl (or wget) isn't required for fetching libssp any longer,
so don't require it while running build-all.sh.
(It's still required by build-cross-tools.sh, for build-make.sh
though.)
As mingw-w64 now provides these routines, we no longer need to build
the original library from GCC.
As building with -fstack-protector-strong still links with -lssp
(and -lssp_nonshared), we still need to provide libraries with these
names, but they can be empty dummy libraries.
When --unwindlib=libunwind is implicit, we need to build libunwind
to have a complete working C compiler too. Currently this is worked
around by initially creating a dummy, empty libunwind.a, but with
the current version of libcxx/libunwind, we can get rid of that
workaround if we build it as soon as possible.
Building this tool requires having a full LLVM build available;
either by installing without LLVM_INSTALL_TOOLCHAIN_ONLY (and not
stripping the llvm installation yet) or by pointing it at the
LLVM build directory instead. The latter works better for our
normal build flows.
Notable changes since 12.0.0 for llvm-mingw are:
llvm:
- Produce proper cross-section relative relocations on ARM and AArch64
- Fixed the calling convention for AArch64 for variadic functions involving
floats in the fixed arguments
- Added a windres compatible frontend in llvm-rc, avoiding the need for
external wrappers
- Build LLVM with -ffunction-sections and --gc-sections, shrinking
a full build of llvm-mingw without LLVM_BUILD_LLVM_DYLIB by 22%
(but llvm-mingw uses LLVM_BUILD_LLVM_DYLIB these days, which shrinks
the build even more)
- Avoid optimizing/changing function calls into stpcpy due to optimizations
- llvm-ml has improved to the point where it can build the OpenMP assembly
file without needing to use another assembler tool
lld:
- Support linking directly against DLLs without using import libraries
- Improved reliability when running on Windows, avoiding some hangs
when terminating
- Fixed linking with --export-all-symbols in combination with
-ffunction-sections
- Fixed --export-all-symbols when linking EXEs
- Fixed autoexport from LTO objects with comdat symbols
- Print warnings with a "ld.lld" prefix instead of "lld-link"
- Avoid thread exhaustion on 32 bit Windows
- Accepting more forms of options, like -static and --stack=
clang:
- Fixed reading long doubles with va_arg on x86_64
- Fixed calling std::once in a dynamically linked libstdc++
runtimes:
- Complete support for std::filesystem in libc++ (which was previously
backported to 12.0.0 in llvm-mingw too, but the previous release had
a bug in using e.g. the u8path() method when linking against the DLL
version of libc++)
- Implemented semaphores in libc++
- Provide the __gcc_personality_seh0 symbol, fixing building C code with
-fexceptions and __attribute__((cleanup))
- Simplified building/installing compiler-rt and libunwind
- Silenced lots of build warnings in OpenMP
For x86_64 and aarch64, this requires https://reviews.llvm.org/D89231.
The C++ destructors aren't executed while doing the longjmp (contrary
to how it works MSVC's C++ exceptions), but it no longer crashes.
Having less available should make debugging in the docker images a bit
more accessible.
Curl is a nice-to-have at the moment, while we also have wget available
from before.
LLVM's OpenMP implementation only supports Windows on x86, and it
requires a MASM-compatible assembler to build it. Build UASM
for this purpose, for now. (UASM isn't available packaged in
debian/ubuntu repos.) In the future, llvm-ml should be able
to handle it instead, but it's not currently mature enough.
Not including it in the regular build-all.sh for now, as UASM
isn't generally available.
This simplifies build-mingw-w64.sh. When building on native
windows (where we also provide unprefixed tools, we can't have
the yet incomplete compiler toolchain in $PATH when building
the mingw-w64 tools. (Logically, build-mingw-w64-tools belong
with build-llvm and install-wrappers; using the original system
compiler to build tools that are supposed to run on the current
machine, as opposed to the cross target, like when building the
runtimes.)
This updates compiler-rt, libunwind, libcxxabi and libcxx to a newer
version, matching the compiler.
This will be the official, canonical repo in the future.
For the non-dev Dockerfile build, this means that all the llvm based
subprojects need to be built in one RUN to avoid storing the llvm
checkout in the docker layers.
Martin Storsjö