The idea is that, other parts of the libc which require thread/lock
support will be able to use this platform independent setup.
With this change, only the linux implementation of a mutex type has been
moved to the new library. Because of this, there is some duplication
between the new library and src/threads/linux. A follow up change will
move all of src/threads/linux to the new library. The duplication should
be eliminated with that move.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D120795
With modern architectures having a thread pointer and language supporting
thread locals, there is no reason to use a function intermediary to access
the thread local errno value.
The entrypoint corresponding to errno has been replaced with an object
library as there is no formal entrypoint for errno anymore.
Reviewed By: jeffbailey, michaelrj
Differential Revision: https://reviews.llvm.org/D120920
The upstream project ships CMake rules for building vanilla gtest/gmock which conflict with the names chosen by LLVM. Since LLVM's build rules here are quite specific to LLVM, prefixing them to avoid collision is the right thing (i.e. there does not appear to be a path to letting someone *replace* LLVM's googletest with one they bring, so co-existence should be the goal).
This allows LLVM to be included with testing enabled within projects that themselves have a dependency on an official gtest release.
Reviewed By: mehdi_amini
Differential Revision: https://reviews.llvm.org/D120789
New methods to the Atomic class have been added as required. Futex
related types have been consolidated at a common place.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D120705
Add LLVM_LIBC_CLANG_TIDY option and allow LLVM_LIBC_ENABLE_LINTING without full build.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D119180
Only the methods currently required by the libc have been added.
Most of the existing uses of atomic operations have been switched over
to this new class. A future change will clean up the rest of uses.
This change now allows building mutex and condition variable code with a
C++ compiler which does not have stdatomic.h, for example g++.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D120642
__builtin_clz requires just a single instruction on x86 and arm, so this is a performance improvement.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D120579
The benchmark framework synthesizes fake "aggregate" Samples representing mean, median and cv.
We're only interested in "iteration" samples.
Differential Revision: https://reviews.llvm.org/D120062
Often atexit is implemented using __cxa_atexit. I have not implemented __cxa_atexit here because it potentially requires more discussion. It is unique for llvm-libc (I think) that it is an exported symbol that wouldn’t be defined in any spec file because it doesn’t have a header. Implementing it will be trivial given what is here already, but I figured it would be more contentious so it can be implemented later.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D119512
Algorithm for hypotf: compute (a*a + b*b) in double precision, then use Dekker's algorithm to find the rounding error, and then correcting it after taking its square-root.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D118157
The prior page was the proposal doc, this one is now
more about what the project intends to do, written in the
present tense.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D119379
This implements a basic arm64 loader for Linux, and all the currently
enabled linker tests pass. TLS is not implemented, and functions
using it will have undefined behaviour. Notably, the TLS test is
currently disabled on x86_64.
Much of the structure is copied from x86_64 to allow for a refactoring
of the start code between architectures.
Tested:
ninja libc_loader_tests on aarch64-linux.
Co-authored-by: Raman Tenneti <rtenneti@google.com>
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D119641
Previously, building LLVM-libc with GWP ASAN was conditioned on the flag
COMPILER_RT_BUILD_GWP_ASAN, which caused issues do to the default value
of the flag being set in the compiler-rt cmake, which is seperate. Now
GWP ASAN is included based on if it exists as a target, which is more
consistent.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D119789
Simplify the logic when the exponent difference is at least MantissaLength + 2, while still maintaining correct rounding for all rounding modes.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D119843
Add support for getenv as defined by the Open Group's "System Interface &
Header" in https://pubs.opengroup.org/onlinepubs/7908799/xsh/getenv.html
getenv requires a standard way of accessing the environment,
so a pointer to the environment is added to the startup in crt1.
Consquently, this function is not usable on top of other libcs.
Added starts_with method to StringView. getenv function uses it.
Co-authored-by: Jeff Bailey <jeffbailey@google.com>
Reviewed By: sivachandra, rtenneti
Differential Revision: https://reviews.llvm.org/D119403
Previously, allocator functions were only available if they were included
from scudo or by using the system libc headers (i.e. by turning off the
full build). This patch changes the logic to include the prototypes for
the allocator functitons in all cases, which allows the linker to link
in the system's allocator.
Reviewed By: sivachandra, abrachet
Differential Revision: https://reviews.llvm.org/D119587
the vector class, due to being dynamically resized, needs malloc. This
fixes the build so that it only includes it when malloc should be
available.
Differential Revision: https://reviews.llvm.org/D119464
Add a basic implementation of the vector class for use internally to
LLVM-libc.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D118954
GCC complains about undefined reference in LibcTest.cpp and indeed the wrong version of the template has been explicitly instanciated.
This is necessary to get llvm-libc compile with GCC.
Mentionning D119002 here for navigability.
Differential Revision: https://reviews.llvm.org/D119242
Although type punning is defined for union in C, it is UB in C++.
This patch introduces a bit_cast function to convert between types in a safe way.
This is necessary to get llvm-libc compile with GCC.
This patch is extracted from D119002.
Differential Revision: https://reviews.llvm.org/D119145
These were all the non OS agnostic implementations I could find in general directories.
Currently none of these functions are actually enabled, but for when they do it makes sense that they be in linux/ specific directories.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D119164
This implementation relies on storing data in registers for sizes up to 128B.
Then depending on whether `dst` is less (resp. greater) than `src` we move data forward (resp. backward) by chunks of 32B.
We first make sure one of the pointers is aligned to increase performance on large move sizes.
Differential Revision: https://reviews.llvm.org/D114637
llvm-libc exhibits a C interface but its source is C++.
This patch explicitly disables the use of exceptions and RTTI when compiling the entrypoints.
Differential Revision: https://reviews.llvm.org/D118889
CMAKE_CXX_STANDARD 14 is set in the llvm-project/llvm folder overriding all COMPILE_OPTIONS -std=c++17. We need to override the CXX_STANDARD property of the target in order to set the correct C++ standard flags.
Reviewed By: gchatelet
Differential Revision: https://reviews.llvm.org/D118871
Stella Laurenzo