Using noexcept multilib with -fno-exceptions can lead to significant
space savings when statically linking libc++abi because we don't need
all the unwinding and demangling code.
When compiling with ASan, we already get a lot of overhead from the
instrumentation itself, when statically linking libc++abi, that overhead
is even larger.
Having the noexcept variant for ASan can help significantly, we've seen
more than 50% size reduction in our system image, which offsets the cost
of having to build another multilib.
Differential Revision: https://reviews.llvm.org/D64140
llvm-svn: 365994
This is a follow up to r361432, changing the layout of per-target
runtimes to more closely resemble multiarch. While before, we used
the following layout:
[RESOURCE_DIR]/<target>/lib/libclang_rt.<runtime>.<ext>
Now we use the following layout:
[RESOURCE_DIR]/lib/<target>/libclang_rt.<runtime>.<ext>
This also more closely resembles the existing "non-per-target" layout:
[RESOURCE_DIR]/lib/<os>/libclang_rt.<runtime>-<arch>.<ext>
This change will enable further simplification of the driver logic
in follow up changes.
Differential Revision: https://reviews.llvm.org/D62469
llvm-svn: 361784
This is a follow up to r361432 and r361504 which addresses issues
introduced by those changes. Specifically, it avoids duplicating
file and runtime paths in case when the effective triple is the
same as the cannonical one. Furthermore, it fixes the broken multilib
setup in the Fuchsia driver and deduplicates some of the code.
Differential Revision: https://reviews.llvm.org/D62442
llvm-svn: 361709
This introduces a support for multilibs to Fuchsia driver. Unlike the
existing multilibs that are used primarily for handling different
architecture variants, we use multilibs to handle different variants
of Clang runtime libraries: -fsanitize=address and -fno-exceptions
are the two we support initially. This replaces the existing support
for sanitized runtimes libraries that was only used by Fuchsia driver
and it also refactors some of the logic to allow sharing between GNU
and Fuchsia drivers.
Differential Revision: https://reviews.llvm.org/D61040
llvm-svn: 359360
This can be used to disable libc linking. This flag is supported by
GCC since version 9 as well as some Clang target toolchains. This
change also includes tests for all -no* flags which previously weren't
covered.
Differential Revision: https://reviews.llvm.org/D58325
llvm-svn: 354208
-static relies on lld's behavior, but -Bstatic/dynamic is supported
across all linkers.
Differential Revision: https://reviews.llvm.org/D54082
llvm-svn: 346107
This makes the tests stricter by not only matching the runtime file
name, but the entire path into the resource directory.
Differential Revision: https://reviews.llvm.org/D54064
llvm-svn: 346088
This avoids introducing unnecessary DT_NEEDED entries when using
C++ driver for linking C code or C++ code that doesn't use C++
standard library.
Differential Revision: https://reviews.llvm.org/D53854
llvm-svn: 346064
The Fuchsia driver relies on lld so invoke clang with
-fuse-ld=lld. This gets the test passing when the clang default linker
is something other than lld.
Differential Revision: https://reviews.llvm.org/D49899
llvm-svn: 339036
This change adds a support for multiarch style runtimes layout, so in
addition to the existing layout where runtimes get installed to:
lib/clang/$version/lib/$os
Clang now allows runtimes to be installed to:
lib/clang/$version/$target/lib
This also includes libc++, libc++abi and libunwind; today those are
assumed to be in Clang library directory built for host, with the
new layout it is possible to install libc++, libc++abi and libunwind
into the runtime directory built for different targets.
The use of new layout is enabled by setting the
LLVM_ENABLE_RUNTIME_TARGET_DIR CMake variable and is supported by both
projects and runtimes layouts. The runtimes CMake build has been further
modified to use the new layout when building runtimes for multiple
targets.
Differential Revision: https://reviews.llvm.org/D45604
llvm-svn: 335809
The fact that libc++ depends on libc++abi and libunwind is an internal
detail that's captured by the libc++.so linker script.
Differential Revision: https://reviews.llvm.org/D46768
llvm-svn: 332138
Passing a flavor to LLD requires command line argument, but if these
are being passed through a response file, this will fail because LLD
needs to know which driver to use before processing the response file.
Use ld.lld directly instead to avoid this issue.
Differential Revision: https://reviews.llvm.org/D39176
llvm-svn: 316379
Several improvements to the Fuchsia driver:
* Search for C++ library headers and libraries in directories that
are part of the toolchain distribution rather than sysroot.
* Use LLVM support utlities to construct paths to make sure the driver
is also usable on Windows for cross-compiling.
* Change the driver to inherit directly from ToolChain rather than
Generic_GCC since we don't need any of the GCC related multilib logic.
Differential Revision: https://reviews.llvm.org/D35328
llvm-svn: 307856
Several improvements to the Fuchsia driver:
* Search for C++ library headers and libraries in directories that
are part of the toolchain distribution rather than sysroot.
* Use LLVM support utlities to construct paths to make sure the driver
is also usable on Windows for cross-compiling.
* Change the driver to inherit directly from ToolChain rather than
Generic_GCC since we don't need any of the GCC related multilib logic.
Differential Revision: https://reviews.llvm.org/D32613
llvm-svn: 307830
I originally requested this to be tested in D25263 but in the end
forgot to make sure that it was done.
Differential Revision: https://reviews.llvm.org/D28289
llvm-svn: 291389
Provide toolchain and tool support for Fuchsia operating system.
Fuchsia uses compiler-rt as the runtime library and libc++, libc++abi
and libunwind as the C++ standard library. lld is used as a default
linker.
Differential Revision: https://reviews.llvm.org/D25117
llvm-svn: 283420
Petr Hosek