PowerPC uses a slightly different type of floats for their 128 bit long
doubles, as "double-double", with __LDBL_MANT_DIG__ == 106 rather than
__LDBL_MANT_DIG__ == 113 for IEEE 128 bit floats.
This fixes compiling libcxxabi for PowerPC after
3b70715c13876c51542ebfe2e3f4ee908f6785cb.
This avoids needing to hardcode the mapping between architectures and
their sizes of long doubles.
This fixes a case in test_demangle.pass.cpp, that previously failed like
this (XFAILed):
.---command stdout------------
| Testing 29859 symbols.
| _ZN5test01hIfEEvRAcvjplstT_Le4001a000000000000000E_c should be invalid
but is not
| Got: 0, void test0::h<float>(char (&) [(unsigned int)(sizeof (float) +
0x0.07ff98f7ep-1022L)])
`-----------------------------
.---command stderr------------
| Assertion failed: !passed && "demangle did not fail", file
libcxxabi/test/test_demangle.pass.cpp, line 30338
`-----------------------------
This testcase is defined within
// Is long double fp80? (Only x87 extended double has 64-bit mantissa)
#define LDBL_FP80 (__LDBL_MANT_DIG__ == 64)
...
#if !LDBL_FP80
...
#endif
The case failed on x86 architectures with an unusual size for long
doubles, as the test expected the demangler to not be able to demangle
an 80 bit long double (based on the `__LDBL_MANT_DIG__ == 64` condition
in the test). However as the libcxxabi implementation was hardcoded to
demangle 80 bit long doubles on x86_64 regardless of the actual size,
this test failed (by unexpectedly being able to demangle it).
By configuring libcxxabi's demangling of long doubles to match what the
compiler specifies, we no longer hit the expected failures in the
test_demangle.pass.cpp test on Android on x86.
This makes libcxxabi require a GCC-compatible compiler that defines
nonstandard defines like `__LDBL_MANT_DIG__`, but I presume that's
already essentially required anyway.
Requirements on character-like types are updated unconditionally,
because `basic_string` does requires the default-constructibility. It
might be possible to make `basic_string_view` support classes with
non-public trivial default constructor, but this doesn't seem sensible.
libcxxabi's `ItaniumDemangle.h` is also updated to avoid deprecated
features.
This makes it clearer that initialization of this global variable is
taking place at compile-time, reducing the likelihood of static
initialization order fiasco.
There doesn't seem to be much benefit in always providing declarations
for the sized deallocations from C++14 onwards if the user explicitly
passed `-fno-sized-deallocation` to disable them. This patch simplifies
the declarations to be available exactly when the compiler expects sized
deallocation functions to be available.
This was needed before https://github.com/llvm/llvm-project/pull/115077
since the compiler-rt test build made assumptions about the build
layout of libc++ and libc++abi, but now they link against a local
installation of these libraries so we no longer need this workaround.
This mechanism is preferable in environments like embedded since it
doesn't require special handling of the custom section.
This is a reland of https://github.com/llvm/llvm-project/pull/114961
which addresses the issue reported by downstream users. Specifically,
the two differences from the previous version are:
* The internal `symbol##_impl__` symbol in the Mach-O implementation is
annotated with `__attribute__((used))` to prevent LTO from deleting it
which we've seen in the previous version.
* `__is_function_overridden` is marked as `inline` so these symbols are
placed in a COMDAT (or fully inlined) to avoid duplicate symbol errors
which we've seen in the previous version.
This disentangles the code which previously had a mix of many #ifdefs, a
non-versioned namespace and a versioned namespace. It also makes it
clearer which parts of <new> are implemented on Windows by including <new.h>.
When using LTO, the deplibs mechanism is insufficient to ensure that
libzircon is always brought into the link prior to LTO code generation.
The general problem is discussed in depth in
https://github.com/llvm/llvm-project/issues/56070
To work around this, we can just provide libzircon as a link input.
The variables are all `constexpr`, which implies `inline`. Since they
aren't `constexpr` in C++03 they're also not `inline` there. Because of
that we define them out-of-line currently. Instead we can use the C++17
extension of `inline` variables, which results in the same weak
definitions of the variables but without having all the boilerplate.
Instead of building the benchmarks separately via CMake and running them
separately from the test suite, this patch merges the benchmarks into
the test suite and handles both uniformly.
As a result:
- It is now possible to run individual benchmarks like we run tests
(e.g. using libcxx-lit), which is a huge quality-of-life improvement.
- The benchmarks will be run under exactly the same configuration as
the rest of the tests, which is a nice simplification. This does
mean that one has to be careful to enable the desired optimization
flags when running benchmarks, but that is easy with e.g.
`libcxx-lit <...> --param optimization=speed`.
- Benchmarks can use the same annotations as the rest of the test
suite, such as `// UNSUPPORTED` & friends.
When running the tests via `check-cxx`, we only compile the benchmarks
because running them would be too time consuming. This introduces a bit
of complexity in the testing setup, and instead it would be better to
allow passing a --dry-run flag to GoogleBenchmark executables, which is
the topic of https://github.com/google/benchmark/issues/1827.
I am not really satisfied with the layering violation of adding the
%{benchmark_flags} substitution to cmake-bridge, however I believe
this can be improved in the future.
While these flags semantically are relevant only for C++, we do add them
to CMAKE_REQUIRED_FLAGS if they are detected. All flags in that variable
are used both when testing compilation of C and C++ (and for detecting
libraries, which uses the C compiler driver).
Therefore, to be sure we safely can add the flags to
CMAKE_REQUIRED_FLAGS, test for the option with the C language.
This should fix compilation with GCC; newer versions of GCC do support
the -nostdlib++ option, but it's only supported by the C++ compiler
driver, not the C driver. (However, many builds of GCC also do accept
the option with the C driver, if GCC was compiled with Ada support
enabled, see [1]. That's why this issue isn't noticed in all
configurations with GCC.)
Clang does support these options in both C and C++ driver modes.
This should fix#90332.
[1]
https://github.com/llvm/llvm-project/issues/90332#issuecomment-2325099254
Instead of placing artifacts for testing the runtimes at <build>/test,
place those artifacts at <build>/<project>/test. This prevents
cluttering the build directory with the runtimes' test artifacts for
everyone else.
As a drive-by, remove LIBCXX_BINARY_INCLUDE_DIR which wasn't used
anymore.
Currently, the library-internal feature test macros are only defined if
the feature is not available, and always have the prefix
`_LIBCPP_HAS_NO_`. This patch changes that, so that they are always
defined and have the prefix `_LIBCPP_HAS_` instead. This changes the
canonical use of these macros to `#if _LIBCPP_HAS_FEATURE`, which means
that using an undefined macro (e.g. due to a missing include) is
diagnosed now. While this is rather unlikely currently, a similar change
in `<__configuration/availability.h>` caught a few bugs. This also
improves readability, since it removes the double-negation of `#ifndef
_LIBCPP_HAS_NO_FEATURE`.
The current patch only touches the macros defined in `<__config>`. If
people are happy with this approach, I'll make a follow-up PR to also
change the macros defined in `<__config_site>`.
This is a purely mechanical commit for fixing the indentation of the
runtimes' CMakeLists files after #80007. That PR didn't update the
indentation in order to make the diff easier to review and for merge
conflicts to be easier to resolve (for downstream changes).
This doesn't change any code, it only reindents it.
This patch always defines the cxx_shared, cxx_static & other top-level
targets. However, they are marked as EXCLUDE_FROM_ALL when we don't want
to build them. Simply declaring the targets should be of no harm, and it
allows other projects to mention these targets regardless of whether
they end up being built or not.
This patch basically moves the definition of e.g. cxx_shared out of the
`if (LIBCXX_ENABLE_SHARED)` and instead marks it as EXCLUDE_FROM_ALL
conditionally on whether LIBCXX_ENABLE_SHARED is passed. It then does
the same for libunwind and libc++abi targets. I purposefully avoided to
reformat the files (which now has inconsistent indentation) because I
wanted to keep the diff minimal, and I know this is an area of the code
where folks may have downstream diffs. I will re-indent the code
separately once this patch lands.
This is a reapplication of 79ee0342dbf0, which was reverted in
a3539090884c because it broke the TSAN and the Fuchsia builds.
Resolves#77654
Differential Revision: https://reviews.llvm.org/D134221
On Apple platforms, using system-libcxxabi as an ABI library wouldn't
work because we'd try to re-export symbols from libc++abi that the
system libc++abi.dylib might not have. Instead, only re-export those
symbols when we're using the in-tree libc++abi.
This does mean that libc++.dylib won't re-export any libc++abi symbols
when building against the system libc++abi, which could be fixed in
various ways. However, the best solution really depends on the intended
use case, so this patch doesn't try to solve that problem.
As a drive-by, also improve the diagnostic message when the user forgets
to set the LIBCXX_CXX_ABI_INCLUDE_PATHS variable, which would previously
lead to a confusing error.
Closes#104672
In 6a884a9aef39, I synchronized the export list of libc++abi to the
export list of libc++. From the linker's perspective, this caused these
symbols to be taken from libc++.dylib instead of libc++abi.dylib.
However, that can be problematic when back-deploying. Indeed, this means
that the linker will encode an undefined reference to be fullfilled by
libc++.dylib, but when backdeploying against an older system, that
symbol might only be available in libc++abi.dylib.
Most of the symbols that started being re-exported after 6a884a9aef39
turn out to be implementation details of libc++abi, so nobody really
depends on them and this back-deployment issue is inconsequential.
However, we ran into issues with a few of these symbols while testing
LLVM 19, which led to this patch. This slipped between the cracks and
that is why the patch is coming so long after the original patch landed.
In the future, a follow-up cleanup would be to stop exporting most of
the _cxxabiv1_foo_type_infoE symbols from both libc++abi and libc++
since they are implementation details that nobody should be relying on.
rdar://131984512
This removes the need for macOS nodes in Buildkite. It also moves to the
proper way of testing backdeployment, which is to actually run on the
target OS itself, instead of using packaged dylibs from previous OS
versions and trying to emulate backdeployment with DYLD_LIBRARY_PATH.
As a drive-by change, also fix a few back-deployment annotations that
were incorrect and add support for minor versions in the Lit feature
determining availability from the target triple.
This is what we started doing in libc++ and it straightens up a lot of
things that only happened to work before, notably the presence of
relative rpaths in dylibs when running from the build tree.
This unlocks the ability to link against a just-built dylib but run
against another version of the dylib (for example the system-provided
one), which is necessary for proper backdeployment testing.
This patch adds a lot of code duplication between the libc++ and
libc++abi testing setups. However, there is already a large amount of
duplication and the only real way to get rid of it is to merge libc++abi
into libc++. In a way, this patch is a step in that direction because it
closes the gap between the two libraries' testing setup.
