There's a lot of duplicated calls to find various compiler-rt libraries
from build of runtime libraries like libunwind, libc++, libc++abi and
compiler-rt. The compiler-rt helper module already implemented caching
for results avoid repeated Clang invocations.
This change moves the compiler-rt implementation into a shared location
and reuses it from other runtimes to reduce duplication and speed up
the build.
Differential Revision: https://reviews.llvm.org/D88458
Summary:
This commit switches libunwind from using the complicated logic in
libc++'s testing configuration to a from-scratch configuration.
I tried to make sure that all cases that were handled in the old
config were handled by this one too, so hopefully this shouldn't
break anyone. However, if you encounter issues with this change,
please let me know and feel free to revert if I don't reply quickly.
This change was engineered to be easily revertable.
This commit is a re-application of 5a8ad80b6f, which was reverted in
070a2ddcb6 because it broke the Bootstrapping build. This has now been
addressed by tweaking the from-scratch config.
Differential Revision: https://reviews.llvm.org/D112082
In 395271a, I simplified how we handled the target triple for the
runtimes. However, in doing so, we stopped considering the default
in CMAKE_CXX_COMPILER_TARGET, so we'd use the LLVM_DEFAULT_TARGET_TRIPLE
(which is the host triple) even if CMAKE_CXX_COMPILER_TARGET was specified.
This commit fixes that problem and also refactors the code so that it's
easy to see what the default value is.
The fact that nobody seems to have been broken by this makes me think
that perhaps nobody is using CMAKE_CXX_COMPILER_TARGET to specify the
triple -- but it should still work.
Differential Revision: https://reviews.llvm.org/D111672
This commit switches libunwind from using the complicated logic in
libc++'s testing configuration to a from-scratch configuration.
I tried to make sure that all cases that were handled in the old
config were handled by this one too, so hopefully this shouldn't
break anyone. However, if you encounter issues with this change,
please let me know and feel free to revert if I don't reply quickly.
This change was engineered to be easily revertable.
Differential Revision: https://reviews.llvm.org/D112082
Running tests for libunwind is a lot simpler than running tests for
libc++, so a simple Lit config file is sufficient. The benefit is that
we disentangle the libunwind test configuration from the libc++ and
libc++abi test configuration. The setup was too complicated, which led
to some bugs (notably we were running against the system libunwind on
Apple platforms).
Differential Revision: https://reviews.llvm.org/D111664
There's a lot of duplicated calls to find various compiler-rt libraries
from build of runtime libraries like libunwind, libc++, libc++abi and
compiler-rt. The compiler-rt helper module already implemented caching
for results avoid repeated Clang invocations.
This change moves the compiler-rt implementation into a shared location
and reuses it from other runtimes to reduce duplication and speed up
the build.
Differential Revision: https://reviews.llvm.org/D88458
This way, we do not need to set LLVM_CMAKE_PATH to LLVM_CMAKE_DIR when (NOT LLVM_CONFIG_FOUND)
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D107717
-Wunused-but-set-variable triggers a warning even the block of code is effectively dead.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D107835
Control-flow Enforcement Technology (CET), published by Intel,
introduces shadow stack feature aiming to ensure a return from
a function is directed to where the function was called.
In a CET enabled system, each function call will push return
address into normal stack and shadow stack, when the function
returns, the address stored in shadow stack will be popped and
compared with the return address, program will fail if the 2
addresses don't match.
In exception handling, the control flow may skip some stack frames
and we must adjust shadow stack to avoid violating CET restriction.
In order to achieve this, we count the number of stack frames skipped
and adjust shadow stack by this number before jumping to landing pad.
Reviewed By: hjl.tools, compnerd, MaskRay
Differential Revision: https://reviews.llvm.org/D105968
Signed-off-by: gejin <ge.jin@intel.com>
-Wunused-but-set-variable triggers a warning even the block of code is effectively dead.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D107835
Instead of using TARGET_TRIPLE, which is always set to LLVM_DEFAULT_TARGET_TRIPLE,
use that variable directly to populate the various XXXX_TARGET_TRIPLE
variables in the runtimes.
This re-applies 77396bbc98 and 5099e01568, which were reverted in
850b57c5fb because they broke the build.
Differential Revision: https://reviews.llvm.org/D106009
When a target triple is specified in CMake via XXX_TARGET_TRIPLE, we tried
passing the --target=<...> flag to the compiler. However, not all compilers
support that flag (e.g. GCC, which is not a cross-compiler). As a result,
setting e.g. LIBCXX_TARGET_TRIPLE=<host-triple> would end up trying to
pass --target=<host-triple> to GCC, which breaks everything because the
flag isn't even supported.
This commit only adds `--target=<...>` & friends to the flags if it is
supported by the compiler.
One could argue that it's confusing to pass LIBCXX_TARGET_TRIPLE=<...>
and have it be ignored. That's correct, and one possibility would be
to assert that the requested triple is the same as the host triple when
we know the compiler is unable to cross-compile. However, note that this
is a pre-existing issue (setting the TARGET_TRIPLE variable never had an
influence on the flags passed to the compiler), and also fixing that is
starting to look like reimplementing a lot of CMake logic that is already
handled with CMAKE_CXX_COMPILER_TARGET.
Differential Revision: https://reviews.llvm.org/D106082
This commit reverts 5099e01568 and 77396bbc98, which broke the build
in various ways. I'm reverting until I can investigate, since that
change appears to be way more subtle than it seemed.
This is a second attempt at D101497, which landed as
9a9bc76c0e but had to be reverted in
8cf7ddbdd4.
This issue was that in the case that `COMPILER_RT_INSTALL_PATH` is
empty, expressions like "${COMPILER_RT_INSTALL_PATH}/bin" evaluated to
"/bin" not "bin" as intended and as was originally.
One solution is to make `COMPILER_RT_INSTALL_PATH` always non-empty,
defaulting it to `CMAKE_INSTALL_PREFIX`. D99636 adopted that approach.
But, I think it is more ergonomic to allow those project-specific paths
to be relative the global ones. Also, making install paths absolute by
default inhibits the proper behavior of functions like
`GNUInstallDirs_get_absolute_install_dir` which make relative install
paths absolute in a more complicated way.
Given all this, I will define a function like the one asked for in
https://gitlab.kitware.com/cmake/cmake/-/issues/19568 (and needed for a
similar use-case).
---
Original message:
Instead of using `COMPILER_RT_INSTALL_PATH` through the CMake for
complier-rt, just use it to define variables for the subdirs which
themselves are used.
This preserves compatibility, but later on we might consider getting rid
of `COMPILER_RT_INSTALL_PATH` and just changing the defaults for the
subdir variables directly.
---
There was a seaming bug where the (non-Apple) per-target libdir was
`${target}` not `lib/${target}`. I suspect that has to do with the docs
on `COMPILER_RT_INSTALL_PATH` saying was the library dir when that's no
longer true, so I just went ahead and fixed it, allowing me to define
fewer and more sensible variables.
That last part should be the only behavior changes; everything else
should be a pure refactoring.
---
I added some documentation of these variables too. In particular, I
wanted to highlight the gotcha where `-DSomeCachePath=...` without the
`:PATH` will lead CMake to make the path absolute. See [1] for
discussion of the problem, and [2] for the brief official documentation
they added as a result.
[1]: https://cmake.org/pipermail/cmake/2015-March/060204.html
[2]: https://cmake.org/cmake/help/latest/manual/cmake.1.html#options
In 38b2dec37e the problem was somewhat
misidentified and so `:STRING` was used, but `:PATH` is better as it
sets the correct type from the get-go.
---
D99484 is the main thrust of the `GnuInstallDirs` work. Once this lands,
it should be feasible to follow both of these up with a simple patch for
compiler-rt analogous to the one for libcxx.
Reviewed By: phosek, #libc_abi, #libunwind
Differential Revision: https://reviews.llvm.org/D105765
The new layout more closely matches the layout used by other compilers.
This is only used when LLVM_ENABLE_PER_TARGET_RUNTIME_DIR is enabled.
Differential Revision: https://reviews.llvm.org/D100869
These variables were introduced during early work on the runtimes build
but were obsoleted by {LIBCXX,LIBCXXABI,LIBUNWIND}_INSTALL_LIBRARY_DIR.
Differential Revision: https://reviews.llvm.org/D99697
Rename the CMake option, LIBUNWIND_HERMETIC_STATIC_LIBRARY, to
LIBUNWIND_HIDE_SYMBOLS. Rename the C macro define,
_LIBUNWIND_DISABLE_VISIBILITY_ANNOTATIONS, to _LIBUNWIND_HIDE_SYMBOLS,
because now the macro adds a .hidden directive rather than merely
suppress visibility annotations.
For ELF, when LIBUNWIND_HIDE_SYMBOLS is enabled, mark unw_getcontext as
hidden. This symbol is the only one defined using src/assembly.h's
WEAK_ALIAS macro. Other unw_* weak aliases are defined in C++ and are
already hidden.
Mach-O doesn't support weak aliases, so remove .weak_reference and
weak_import. When LIBUNWIND_HIDE_SYMBOLS is enabled, output
.private_extern for the unw_* aliases.
In assembly.h, add missing SYMBOL_NAME macro invocations, which are
used to prefix symbol names with '_' on some targets.
Fixes PR46709.
Reviewed By: #libunwind, phosek, compnerd, steven_wu
Differential Revision: https://reviews.llvm.org/D93003
cmake_minimum_required(VERSION) calls cmake_policy(VERSION),
which sets all policies up to VERSION to NEW.
LLVM started requiring CMake 3.13 last year, so we can remove
a bunch of code setting policies prior to 3.13 to NEW as it
no longer has any effect.
Reviewed By: phosek, #libunwind, #libc, #libc_abi, ldionne
Differential Revision: https://reviews.llvm.org/D94374
Remove check for standalone and shared library mode in libcxxabi to
allow including tests in said mode. This check prevented running the
tests in standalone mode with static libraries, which is the case for
baremetal targets.
Fix check-unwind target trying to use a non-existent llvm-lit executable
in standalone mode. Copy the HandleOutOfTreeLLVM logic from libcxxabi to
libunwind in order to make the tests work in standalone mode.
Reviewed By: ldionne, #libc_abi, #libc
Differential Revision: https://reviews.llvm.org/D86540
There are several places in LLVM's CMake setup that try to remove the
`stdlib=...` flag from the CMake flags. All this code however only considered
the `-stdlib=` variant of the flag but not the alternative spelling with a
double dash. This causes that when one adds `--stdlib=...` to the user-provided
CMake flags that this gets transformed into just `-` which ends up causing the
build system to think it should read the source from stdin (which then lead to
very confusing build errors).
This just adds the alternative spelling before the`-stdlib=` variant in all
these places
Reviewed By: ldionne
Differential Revision: https://reviews.llvm.org/D87133
Configure default value of `LLVM_ENABLE_WARNINGS` in `HandleLLVMOptions.cmake`.
`LLVM_ENABLE_WARNINGS` is documented as ON by default, but `HandleLLVMOptions` assumes the default has been set somewhere else. If it has not been explicitly set, then `HandleLLVMOptions` implicitly uses OFF as a default.
This removes the various `option()` declarations in favor of a single declaration in `HandleLLVMOptions`. This will prevent the unwanted use of `-w` that is mentioned in a couple of the comments.
Reviewed By: DavidTruby, #libunwind, JDevlieghere, compnerd
Differential Revision: https://reviews.llvm.org/D87243
Although it works fine with glibc, as currently implemented the
frameheader cache is incompatible with certain platforms with
slightly different locking semantics inside dl_iterate_phdr.
Therefore only enable it when it is turned on explicitly with
a configure-time option.
Differential Revision: https://reviews.llvm.org/D86163
Set -Wno-suggest-override where such warning is provided
by the compiler when building libunwind, alongside libcxx
and libcxxabi, using recent Clang. This extends behavior
introduced in 77e0e9e17d
to libunwind, avoiding a large amount of warnings during
builds. See D84126 for the original patch.
Libunwind uses _LIBUNWIND_IS_BAREMETAL in a lot of places but there is no cmake variable to set it. This patch adds such a variable. It is quite like what LIBCXXABI_BAREMETAL does in libcxxabi.
Reviewed By: compnerd, #libunwind
Differential Revision: https://reviews.llvm.org/D84759
After this change, we need to explicitly list the languages the
project uses, otherwise the assembly source files won't get built
at all.
Previously (before that commit), the assembly source files were
simply treated as C.
The toplevel llvm CMakeLists.txt adds these three languages, so
when building libunwind integrated as part of that, it works fine.
Summary:
Relands https://reviews.llvm.org/D70815.
The original commit set `CMAKE_TRY_COMPILE_TARGET_TYPE` to
`STATIC_LIBRARY` globally in libunwind/CMakeLists.txt, which effectively
disabled the linking step in CMake checks.
This broke some builds (see 938c70b86c).
Here we set CMAKE_TRY_COMPILE_TARGET_TYPE to
STATIC_LIBRARY only when checking for presence of the `-funwind-tables`
flag, and then set it back to the original value so it doesn't affect
other checks.
Reviewers: mstorsjo, jfb
Subscribers: mgorny, christof, libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D71117
This reverts commit b3fdf33ba6.
This change broke building libunwind for Windows/MinGW, and broke
on aspect of the CMake tests in libunwind in general.
After set(CMAKE_TRY_COMPILE_TARGET_TYPE STATIC_LIBRARY), CMake
skips the linking step in tests, but cmake/config-ix.cmake also
does a few checks for functions in libraries (looking for whether
-lc provides fopen and whether -ldl provides dladdr).
As CMake only tests building a static library, these tests
incorrectly succeed and CMake concludes "Looking for fopen in c -
found" and "Looking for dladdr in dl - found", while building
then fails at the end with errors about unable to find -lc and -ldl.
Summary:
Or, rather, don't accidentally forget to pass it.
This is aimed to solve the problem discussed in [this thread](http://lists.llvm.org/pipermail/llvm-dev/2019-November/136890.html), and to fix [a year-old bug](https://bugs.llvm.org/show_bug.cgi?id=38468).
TL;DR: when building libunwind for ARM Linux, we **need** libunwind to be built with the `-funwind-tables` flag, because, well ARM EHABI needs unwind info produced by this flag. Without the flag all the procedures in libunwind are marked `.cantunwind`, which causes all sorts of bad things. From `_Unwind_Backtrace` not working, to C++ exceptions not being caught (which is the aforementioned bug is about).
Previously, this flag was not added because the CMake check `add_compile_flags_if_supported(-funwind-tables)` produced a false negative. Why? With this flag, the compiler generates calls to the `__aeabi_unwind_cpp_pr0` symbol, which is defined in libunwind itself and obviously is not available at configure time, before libunwind is built. This led to failure at link time during the CMake check. We handle this by disabling the linker for CMake checks in linbunwind.
Also, this patch introduces a lit feature `libunwind-arm-ehabi`, which is used to mark the `signal_frame.pass.cpp` test as unsupported (as was advised by @miyuki in D70397).
Reviewers: peter.smith, phosek, EricWF, compnerd, jroelofs, saugustine, miyuki, jfb
Subscribers: mgorny, kristof.beyls, christof, libcxx-commits, miyuki
Tags: #libc
Differential Revision: https://reviews.llvm.org/D70815
996e62eef7 added Linux-specific dependent libraries to libunwind
sources. As a result, building libunwind with modern LLD on *BSD
started failing due to trying to link libdl. Instead, add those
libraries only if they were detected by CMake.
While technically we could create a long list of systems that need -ldl
and -lpthread, maintaining a duplicate list makes little sense when
CMake needs to detect it for non-LLD systems anyway. Remove existing
system exceptions since they should be covered by the CMake check
anyway.
Remove -D_LIBUNWIND_HAS_COMMENT_LIB_PRAGMA since it is no longer
explicitly needed, if we make the library-specific defines dependent
on presence of this pragma support.
Differential Revision: https://reviews.llvm.org/D70868
There are few differences in compile flags introduced in r374606
which are causing libcxx-libcxxabi-libunwind-armv8-linux to fail.
This change should address all of those, I've compared the generated
build file from before r374606 and with this change and the set of
flags is the same modulo order.
llvm-svn: 374624
libunwind was using its own set of macros/functions for flag checking
which was similar but different from libc++ and libc++abi. This made
it difficult to replicate the same checks across projects, in fact
there were some checks that appear to have been copy & pasted from
another project and that were broken in the standalone libunwind build.
This change refactors flag checks to match libc++ and libc++abi using
a copy of HandleLibunwindFlags.cmake which is derived from the versions
used by the other projects. This also paves a road to deduplicating and
unifying HandleLibunwindFlags.cmake, HandleLibcxxabiFlags.cmake and
HandleLibcxxFlags.cmake post monorepo switch.
Differential Revision: https://reviews.llvm.org/D68855
llvm-svn: 374606
Petr Hosek