Allow setting up the projects with symlinks by passing --symlink-projects
to the build script.
The setup with symlinks is mostly useful in development setups, where
one wants to share ccache across multiple checkouts.
If the SYNC variable is set when running build-all.sh, all the
individual scripts will try to check out the intended version
before building. All scripts that build projects from llvm-project
(build-libcxx.sh, build-compiler-rt.sh, build-openmp.sh) call
build-llvm.sh with CHECKOUT_ONLY=1 to make sure the right version
is checked out (as one can call the scripts individually too).
If the llvm-project directory was a full (non-shallow) checkout,
the repeated fetch was quick as git knew that it had the fetched
reference already. But in a shallow clone, a new shallow fetch
would refetch the whole object tree for the targeted reference.
Using "git cat-file -e" we can check whether a specific object
exists in the local checkout, avoiding needlessly refetching
everything.
However, when fetching a tag using shallow fetch (git fetch
--depth 1 origin "$LLVM_VERSION"), it would only fetch the
commit object for that tag, not the tag itself. By specifying
'tag "$LLVM_VERSION"' in this case, we get the tag object itself,
so that we later can check whether "$LLVM_VERSION" exists in the
local checkout. But this requires guessing whether a specific
"$LLVM_VERSION" is a tag or a commit.
Notable changes include:
- Default to DWARF 4 instead of 5 for the mingw target
- Fix the section name encoding in llvm-objcopy/llvm-strip, if the output
binary has more than 10^6 bytes of string table
This includes building universal binaries (for arm64 and x86_64)
and targeting an older minimum deployment target.
(Before 1919720fdd348ca568b235bf3f1357c198eccd15 in llvm-project,
Jan 2022, building lldb's debugserver failed, if building for macOS
for multiple architectures, or for an architecture other than the
current host.)
Notable changes include:
- LLVM can be configured to prefer forward slashes on Windows, avoiding
the need to manually filter the Clang output in a wrapper for some
commands.
- New Clang options for silencing warnings about unused arguments,
avoiding the need to turn off the warning altogether. This makes
llvm-mingw produce warnings about unused arguments among the user
provided arguments, which never were seen before.
- Improvements to building libunwind/libcxxabi/libcxx, allowing
simplifying the build a lot.
- Fixed generated calls to support routines for converting 128 bit integers
from/to floats on x86_64.
- Fixed the -m32 flag, to let it figure out the right i386/arm
architecture variant (where it previously looked for a sysroot named
e.g. i386-*, which wasn't found).
- Fixed code generation for AArch64 in large object files (over 1 MB of
code), where relocations against temporary symbols (jump tables,
constant pools etc) were broken.
- Fixed continuing from breakpoints and singlestepping in LLDB on
ARM/AArch64
- Fixed unwind info for overridden weak symbols (e.g. if overriding
operator new with a statically linked libc++, and unwinding an exception
through the operator).
- Set proper COFF symbol types for function aliases (e.g. for some C++
constructors), making GNU ld export all of the correctly as the right
type, when linking a DLL.
- Improved code generation for ARM, by assuming less strict alignment
requirements for some instructions.
This is the build host python, run during the build/install,
not to be run on the target device. LLVM's build system itself
detects the python to use for that and overwrites the
Python3_EXECUTABLE variable anyway, so it's value isn't currently
used.
In addition to the changes in 13.0.0 RC1 (listed in
9188cce153), the following changes
relevant to llvm-mingw were made:
- Allow specifying language to llvm-rc with an 0x prefix
- Let the last specified option of -mconsole/-mwindows take effect
- Support both "--opt value" and "--opt=value" for more options in lld
- Add support for the --disable-dynamicbase option spelling in lld,
in addition to the old existing --no-dynamicbase
- Fix linking with when enabling profiling
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
Notable changes in this release:
- Implicitly add the .exe suffix, even when cross compiling (matching
a behaviour change in GCC since GCC 8)
- Enable the dynamicbase flag by default in LLD
- Implemented the -wrap option in LLD
- Optimized the generated unwind data for aarch64, reducing the size
of the unwind data by around 60%
- Error out of LLD if trying to create a DLL with too many exports
Printing '<triple>' causes the shell to try to read a file named
triple. One could either quote it, or just remove the angle brackets;
removing the brackets for simplicity.
Notable changes since LLVM 10.0.0:
- Enable -mms-bitfields by default (like GCC), don't produce errors
if the -mms-bitfields option is used together with non-trivial C++
classes
- Support for more linker flags in LLD (--disable-auto-import,
--disable-runtime-pseudo-reloc, --file-alignment, --section-alignment),
and fixed the handling of the --no-seh flag
- Clearly error out on unsupported relocation types in aarch64 assembly
- Proper support for __attribute__((weak))
- Minor improvements to details in llvm-rc
- Fixed a regression in LLD about exporting symbols containing periods ('.')
with a def file
These aren't strictly necessary any longer, as the external libs
are used automatically if found (instead of erroring out if not
found, unless explicitly disabled as before).
Still keeping the explicit disables, to avoid potential issues if
e.g. the libs are found but exist in an incompatible version.
Notable changes since the previously pinned (early December 2019)
version:
- Implicitly add the .exe suffix if not provided in the clang
-o argument, when running on windows (to match GCC's behaviour)
- Fixes for accesses to TLS variables in another object file
- Fixes for accessing weak functions that may be undefined, on ARM and AArch64
(x86 was fixed earlier)
- Fixed many instances of locale handling in libcxx
These defines were renamed in lldb git master, soon after the current
pinned version.
This fixes building with a later version of llvm than the pinned one.
Notable changes since the previous version are:
- Added a lld option for requesting delay loading libraries
- Allowing using custom .edata from input object files in lld (for Wine)
- Fixed llvm-dlltool with symbol renaming with stdcall decorations
- Supporting merging resources from more than one resource object file in lld
- Improved error messages for duplicate or undefined symbols in lld
(including demangling C++ symbols and printing source locations
where possible)
- Made lld look for for more library name patterns, matching GNU ld
- Brushed up support for using LLDB for, and building on, mingw
- Implemented initial support for armv7 and aarch64 windows in LLDB
build-mingw-w64.sh already provides --with-default-msvcrt option, but
this makes it more convenient to use build-all.sh with non-default
msvcrt config.
This makes cmake use relative paths to all source files, allowing ccache
to reuse compilation results from different source trees in different
directories.
Keep using LLVM_ENABLE_PROJECTS on msys, where symlinks aren't supported.
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.
This version adds support for a version of the -pdb option to the MinGW
frontend to lld that can work without a parameter, and implements --help
and -v for the same frontend.
Martin Storsjö