Summary:
The ABI version used by libc++ is a configuration option just like any other
configuration option. It is a knob that can be used by vendors to customize
the libc++ that they ship. As such, we should not be hardcoding vendor-specific
configuration choices in libc++.
When building libc++ for Fuchsia, Fuchsia's build scripts should simply define
the libc++ ABI version to 2 -- this will result in the _LIBCPP_ABI_VERSION
macro being defined in the __config header that is generated when libc++ is
built and installed, which is the correct way to customize libc++'s behavior
for specific vendors.
Reviewers: phosek, EricWF
Subscribers: mgorny, christof, dexonsmith, cfe-commits, libcxx-commits
Differential Revision: https://reviews.llvm.org/D52397
llvm-svn: 343079
Summary:
https://reviews.llvm.org/D49240 led to symbol size problems in Chromium, and
we expect this may be the case in other projects built in debug mode too.
Instead, unless users explicitly ask for internal_linkage, we use always_inline
like we used to.
In the future, when we have a solution that allows us to drop always_inline
without falling back on internal_linkage, we can replace always_inline by
that.
Note that this commit introduces a change in contract for existing libc++
users: by default, libc++ used to guarantee that TUs built with different
versions of libc++ could be linked together. With the introduction of the
_LIBCPP_HIDE_FROM_ABI_PER_TU macro, the default behavior is that TUs built
with different libc++ versions are not guaranteed to link. This is a change
in contract but not a change in behavior, since the current implementation
still allows linking TUs built with different libc++ versions together.
Reviewers: EricWF, mclow.lists, dexonsmith, hans, rnk
Subscribers: christof, cfe-commits
Differential Revision: https://reviews.llvm.org/D50652
llvm-svn: 339874
This option should be available if LIBCXX_ENABLE_SHARED is enabled,
not LIBCXX_ENABLE_STATIC.
This fixes a typo from SVN r337814.
Differential Revision: https://reviews.llvm.org/D50691
llvm-svn: 339697
The bots were failing to build the cxx_filesystem target, so the
tests were failing. Though this does lead me to wonder how it
was ever working with c++experimental.
llvm-svn: 338095
This patch implements the <filesystem> header and uses that
to provide <experimental/filesystem>.
Unlike other standard headers, the symbols needed for <filesystem>
have not yet been placed in libc++.so. Instead they live in the
new libc++fs.a library. Users of filesystem are required to link this
library. (Also note that libc++experimental no longer contains the
definition of <experimental/filesystem>, which now requires linking libc++fs).
The reason for keeping <filesystem> out of the dylib for now is that
it's still somewhat experimental, and the possibility of requiring an
ABI breaking change is very real. In the future the symbols will likely
be moved into the dylib, or the dylib will be made to link libc++fs automagically).
Note that moving the symbols out of libc++experimental may break user builds
until they update to -lc++fs. This should be OK, because the experimental
library provides no stability guarantees. However, I plan on looking into
ways we can force libc++experimental to automagically link libc++fs.
In order to use a single implementation and set of tests for <filesystem>, it
has been placed in a special `__fs` namespace. This namespace is inline in
C++17 onward, but not before that. As such implementation is available
in C++11 onward, but no filesystem namespace is present "directly", and
as such name conflicts shouldn't occur in C++11 or C++14.
llvm-svn: 338093
Since r337668, we support statically linking dependencies only to shared
or static library. However, that change hasn't updated the check whether
to generate a linker script. We shouldn't generate linker script only in
the case when we aren't statically linked ABI into the shared library.
Differential Revision: https://reviews.llvm.org/D49834
llvm-svn: 338006
This is a refinement on r337833. Previously we were installing two
copies of c++abi headers in libc++ build directory, one in
include/c++build and another one in include/c++/v1. However, the
second copy is unnecessary when building libc++ standalone.
Differential Revision: https://reviews.llvm.org/D49752
llvm-svn: 337979
Currently it's only possible to control whether shared or static library
build of libc++, libc++abi and libunwind is enabled or disabled and
whether to install everything we've built or not. However, it'd be
useful to have more fine grained control, e.g. when static libraries are
merged together into libc++.a we don't need to install libc++abi.a and
libunwind.a. This change adds this option.
Differential Revision: https://reviews.llvm.org/D49573
llvm-svn: 337867
This is an alternative approach to r337727 which broke the build
because libc++ headers were copied into the location outside of
directories used by Clang. This change sets LIBCXX_HEADER_DIR to
different values depending on whether libc++ is being built as
part of LLVM w/ per-target multiarch runtime, LLVM or standalone.
Differential Revision: https://reviews.llvm.org/D49711
llvm-svn: 337833
Currently it's possible to select whether to statically link unwinder
or the C++ ABI library, but this option applies to both the shared
and static library. However, in some scenarios it may be desirable to
only statically link unwinder and C++ ABI library into static C++
library since for shared C++ library we can rely on dynamic linking
and linker scripts. This change enables selectively enabling or
disabling statically linking only to shared or static library.
Differential Revision: https://reviews.llvm.org/D49502
llvm-svn: 337668
Do not use LLVM_RUNTIMES_LIBDIR_SUFFIX variable which is an internal
variable used by the runtimes build from individual runtimes, instead
set per-runtime librarhy directory suffix variable which is necessary
for the sanitized runtimes build to install libraries into correct
location.
Differential Revision: https://reviews.llvm.org/D49121
llvm-svn: 336713
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
Summary:
As noted in a discussion about testing the LLVM 6.0.0 release candidates
(with libc++) for FreeBSD, many tests turned out to fail with
"exception_ptr not yet implemented". This was because libc++ did not
choose the correct C++ ABI library, and therefore it fell back to the
`exception_fallback.ipp` header.
Since FreeBSD 10.x, we have been using libcxxrt as our C++ ABI library,
and its headers have always been installed in /usr/include/c++/v1,
together with the (system) libc++ headers. (Older versions of FreeBSD
used GNU libsupc++ by default, but these are now unsupported.)
Therefore, if we are building libc++ for FreeBSD, set:
* `LIBCXX_CXX_ABI_LIBNAME` to "libcxxrt"
* `LIBCXX_CXX_ABI_INCLUDE_PATHS` to "/usr/include/c++/v1"
by default.
Reviewers: emaste, EricWF, mclow.lists
Reviewed By: EricWF
Subscribers: mgorny, cfe-commits, krytarowski
Differential Revision: https://reviews.llvm.org/D43166
llvm-svn: 324855
When CMAKE_SYSROOT or CMAKE_FIND_ROOT_PATH is set, cmake
recommends setting CMAKE_FIND_ROOT_PATH_MODE_INCLUDE=ONLY
globally which means find_path() always prepends CMAKE_SYSROOT or
CMAKE_FIND_ROOT_PATH to all paths used in the search.
However, this find_path() invocation is looking for a path in the
libcxxabi project on the host system, not the target system,
which can be done by passing NO_CMAKE_FIND_ROOT_PATH.
Differential Revision: https://reviews.llvm.org/D41622
llvm-svn: 323143
This allows keeping libcxx using win32 threads even if a
version of pthread.h is installed.
This matches the existing cmake option LIBCXX_HAS_PTHREAD_API.
Also add missing documentation about the internal define
_LIBCPP_HAS_THREAD_API_WIN32.
Differential Revision: https://reviews.llvm.org/D41764
llvm-svn: 321896
AddLLVM is needed for several functions that are used in tests and
as such needs to be included from the right context which previously
wasn't the case.
Differential Revision: https://reviews.llvm.org/D40280
llvm-svn: 319515
The vcruntime headers are hairy and clash with both libc++ headers
themselves and other libraries. libc++ normally deals with the clashes
by deferring to the vcruntime headers and silencing its own definitions,
but for clients which don't want to depend on vcruntime headers, it's
desirable to support the opposite, i.e. have libc++ provide its own
definitions.
Certain operator new/delete replacement scenarios are not currently
supported in this mode, which requires some tests to be marked XFAIL.
The added documentation has more details.
Differential Revision: https://reviews.llvm.org/D38522
llvm-svn: 315234
Make it clear that these are intended only to force a specific ABI when
the autodetection would give the wrong result by renaming the cmake
options and adding separate forcing macros, as suggested by EricWF in
the post-commit review of r314949 and further discussed on IRC.
llvm-svn: 314965
libc++'s current heuristic for detecting Itanium vs. Microsoft ABI falls
short in some cases. For example, it will detect windows-itanium targets
as using the Microsoft ABI, since they set `_MSC_VER` (for compatibility
with Microsoft headers). Leave the current heuristic in place by default
but also allow users to explicitly specify the ABI if need be.
llvm-svn: 314949
Some ABI macros affect headers, so it's nice to have a site config
option for them. Add a LIBCXX_ABI_DEFINES cmake macro to allow
specifying a list of ABI macros to define in the site config.
The primary design constraint (as discussed with Eric on IRC a while
back) was to not have to repeat the ABI macro names in cmake, which only
leaves a free-form cmake list as an option. A somewhat unfortunate
consequence is that we can't verify that the ABI macros being defined
actually exist, though we can at least perform some basic sanity
checking, since all the ABI macros begin with _LIBCPP_ABI_.
Differential Revision: https://reviews.llvm.org/D36719
llvm-svn: 314946
After speaking with the libcxx owners, they agreed that this is
a bug in the bot that needs to be fixed by the bot owners, and
the CMake changes are correct.
llvm-svn: 313643
This reverts commit 4ad71811d45268d81b60f27e3b8b2bcbc23bd7b9.
There is a bot that is checking out libcxx and lit with nothing
else and then running lit.py against the test tree. Since there's
no LLVM source tree, there's no LLVM CMake. CMake actually
reports this as a warning saying unsupported libcxx configuration,
but I guess someone is depending on it anyway.
llvm-svn: 313607
If we define cmake macros that require a site config, and then undefine
all such macros, a stale site config header will be left behind.
Explicitly delete any generate site config if we don't need one to avoid
this.
Differential Revision: https://reviews.llvm.org/D36720
llvm-svn: 313284
This is going to be used by the runtime build in the multi-target
setup to allow using different install prefix for each target.
Differential Revision: https://reviews.llvm.org/D33762
llvm-svn: 307615
r296685 started adding the test/ subdirectory even when
LIBCXX_INCLUDE_TESTS=OFF. This is great for testing libcxx standalone,
but it also breaks the build when the test/ subdirectory is removed
(and our submission system strips all test/ directories).
This patch updates the logic to check for test/ before adding it.
rdar://problem/31931366
llvm-svn: 302095
Summary:
libc++abi is never the right option for LIBCXX_TARGETING_MSVC, since it
targets the Itanium ABI, whereas MSVC uses the Microsoft ABI. Make the
default ABI be vcruntime when targeting MSVC even if libc++abi is
present in the tree.
Differential Revision: https://reviews.llvm.org/D32320
llvm-svn: 300921
CMake has the problem with the single dash variant because of the
space, so use the double dash with equal sign version. We also
don't have to pass the target triple when checking for compiler-rt
since that flag is already included in compile flags now.
Differential Revision: https://reviews.llvm.org/D32068
llvm-svn: 300409
Clang doesn't produce gcov compatible coverage files. This
causes lcov to break because it uses gcov by default. This
patch switches lcov to use llvm-cov as the gcov-tool.
Unfortunatly llvm-cov doesn't provide a gcov like interface by
default so it won't work with lcov. However `llvm-cov gcov` does.
For this reason we generate 'llvm-cov-wrapper' script that always
passes the gcov flag.
llvm-svn: 297553
Summary:
Currently both libc++ and libc++abi provide definitions for operator new/delete. However I believe this is incorrect and that one or the other should offer them.
This patch adds the CMake option `-DLIBCXX_ENABLE_NEW_DELETE_DEFINITIONS` which defaults no `ON` unless `-DLIBCXXABI_ENABLE_NEW_DELETE_DEFINITIONS=ON` is specified.
Reviewers: mclow.lists, mehdi_amini, dexonsmith, danalbert, smeenai, mgorny, rmaprath
Reviewed By: mehdi_amini
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D30516
llvm-svn: 296802
This patch changes the CMake configuration so that it always
generates the test/lit.site.cfg file, even when testing is disabled.
This allows users to test libc++ without requiring them to have
a full LLVM checkout on their machine.
llvm-svn: 296685
This recommits r294707 with additional fixes. The main difference is
libc++ now correctly builds without any ABI library.
exception.cpp is a bloody mess. It's full of confusing #ifdef branches for
each different ABI library we support, and it's getting unmaintainable.
This patch breaks down exception.cpp into multiple different header files,
roughly one per implementation. Additionally it moves the definitions of
exceptions in new.cpp into the correct implementation header.
This patch also removes an unmaintained libc++abi configuration.
This configuration may still be used by Apple internally but there
are no other possible users. If it turns out that Apple still uses
this configuration internally I will re-add it in a later commit.
See http://llvm.org/PR31904.
llvm-svn: 294730
exception.cpp is a bloody mess. It's full of confusing #ifdef branches for
each different ABI library we support, and it's getting unmaintainable.
This patch breaks down exception.cpp into multiple different header files,
roughly one per implementation. Additionally it moves the definitions of
exceptions in new.cpp into the correct implementation header.
This patch also removes an unmaintained libc++abi configuration.
This configuration may still be used by Apple internally but there
are no other possible users. If it turns out that Apple still uses
this configuration internally I will re-add it in a later commit.
See http://llvm.org/PR31904.
llvm-svn: 294707
When building as part of runtimes, there is no predefined order in
which the runtimes are loaded, so the targets from other projects
might not be available. We need to rely on HAVE_<name> variables
instead in that case.
Differential Revision: https://reviews.llvm.org/D29575
llvm-svn: 294553
It is my opinion that libc++ should never use `<cassert>`, including in the `dylib`.
This patch remove all uses of `assert` from within libc++ and replaces most of them with `_LIBCPP_ASSERT` instead.
Additionally this patch turn `LIBCXX_ENABLE_ASSERTIONS` off by default,
because the standard library should not be aborting user programs unless explicitly asked to.
llvm-svn: 294107
This reverts commit r292883. Unfortunately <string_view> uses
_LIBCPP_ASSERT in a way which is not compatible with the C++11 dylib
build. I'll investigate more tomorrow.
llvm-svn: 292923
Summary:
It is my opinion that libc++ should never use `<cassert>`, including in the `dylib`. This patch remove all uses of `assert` from within libc++ and replaces most of them with `_LIBCPP_ASSERT` instead.
Additionally this patch turn `LIBCXX_ENABLE_ASSERTIONS` off by default, because the standard library should not be aborting user programs unless explicitly asked to.
Reviewers: mclow.lists, compnerd, smeenai
Reviewed By: mclow.lists
Subscribers: mgorny, cfe-commits
Differential Revision: https://reviews.llvm.org/D29063
llvm-svn: 292883
This patch contains multiple cleanups and fixes to better support building on
Windows.
* [Test] Fix handling of library runtime search paths by correctly adding them
to the PATH variable when running the tests.
* [Test] Don't explicitly force "--target=i686-pc-windows" when running the
test suite. Clang++ seems to deduce the correct target.
* [Test] Fix `.sh.cpp` tests on Windows by properly escaping flags used in
shell commands. Specifically windows style paths which included spaces
were causing these tests to fail.
* [CMake] Add "vcruntime" to the list of supported C++ ABI libraries in CMake, and
teach the test suite how to handle it. For now libc++ defaults to using
"vcruntime" on Windows except when libc++abi is in tree; That is probably
a bug and should be changed to always use vcruntime, at least for now.
* [Misc] Move the "c++-build" include directory to the libc++ binary dir
instead of the top level project dir and rename it "c++build". This is just
misc cleanup. Libc++ shouldn't be creating internal build files and directories
at the top-level projects root.
* [Misc] Build type_info's destructor when building for MSVC. This is a temporary
work around to prevent link errors until we have a proper type_info
implementation.
llvm-svn: 292157
Summary: This patch allows libc++ to be built against the debug MSVC runtimes instead of just the release ones.
Reviewers: rnk, majnemer, compnerd, smeenai
Subscribers: mgorny, cfe-commits
Differential Revision: https://reviews.llvm.org/D28725
llvm-svn: 292006
Summary:
This patch attempts to fix the libc++ build/link so that it doesn't use an default C++ libraries on Windows. This is needed to prevent linking to MSVC's STL library.
Additionally this patch changes libc++ so that it is always linked with the non-debug DLL's (e.g. `/MD`). This is needed so that the test suite can correctly link the same libraries without needing to know which configuration `c++.dll` was linked with.
Reviewers: compnerd, rnk, majnemer, kimgr, awson, halyavin, smeenai
Subscribers: cfe-commits, mgorny
Differential Revision: https://reviews.llvm.org/D28441
llvm-svn: 292001
When doing standalone build, check that we actually have libcxxabi
before attempting to use it.
Differential Revision: https://reviews.llvm.org/D28580
llvm-svn: 291723
There is no guaranteed order in which CMake files for individual
runtimes are invoked and therefore we cannot rely on existence of
targets defined in other runtimes. Use the new HAVE_<name> options
instead in those cases.
Differential Revision: https://reviews.llvm.org/D28391
llvm-svn: 291632
This is to make sure this check is called even when building as
part of LLVM runtimes when we are doing standalone but not out of
tree build.
Differential Revision: https://reviews.llvm.org/D28392
llvm-svn: 291592
Need to allow unresolved symbols in the dylib. This was previously done for
LIBCXX_HAS_EXTERNAL_THREAD_API, but we have since split that into two with
LIBCXX_BUILD_EXTERNAL_THREAD_LIBRARY being the externally-threaded variant.
Also a minor CMakeLists.txt cleanup.
llvm-svn: 291433
Summary:
This patch attempts to clean up the macro configuration mess in `<__threading_support>`, specifically the mess involving external threading variants. Additionally this patch adds design documentation for `<__threading_support>` and the configuration macros it uses.
The primary change in this patch is separating the idea of an "external API" provided by `<__external_threading>` and the idea of having an external threading library. Now `_LIBCPP_HAS_THREAD_API_EXTERNAL` means that libc++ should use `<__external_threading>` and that the header is expected to exist. Additionally the new macro `_LIBCPP_HAS_THREAD_LIBRARY_EXTERNAL` is now used to configure for using an "external library" with the default threading API.
Reviewers: compnerd, rmaprath
Subscribers: smeenai, cfe-commits, mgorny
Differential Revision: https://reviews.llvm.org/D28316
llvm-svn: 291275
This patch re-commits a previous attempt to support building libc++ w/o
an ABI library. That patch was originally reverted because:
1) It forgot to teach the test suite about "default" ABI libraries.
2) Some LLVM builders don't clear the CMake cache between builds. The previous
patch caused those builders to fail since their old cache entry for
LIBCXX_CXX_ABI="" is no longer valid.
The updated patch addresses both issues. It works around (2) by adding
a hack to force the builders to update their cache entries. The hack will
be removed shortly once all LLVM builders have run.
Original commit message
-----------------------
Typically libc++ uses libc++abi or libcxxrt to provide the ABI and runtime bits
of the C++ STL. However we also support building w/o an ABI library entirely.
This patch fixes building libc++ w/o an ABI library (and incorporates the
`~type_info()` fix in D28211).
The main changes in this patch are:
1) Add `-DLIBCXX_CXX_ABI=default` instead of using the empty string to mean "default".
2) Fix CMake bits which treated "none" as "default" on OS X.
3) Teach the source files to respect `-D_LIBCPP_BUILDING_HAS_NO_ABI_LIBRARY`.
4) Define ~type_info() when _LIBCPP_BUILDING_HAS_NO_ABI_LIBRARY is defined.
Unfortunately this patch doesn't help clean up the macro mess that we use to
configure for different ABI libraries.
llvm-svn: 290849
Typically libc++ uses libc++abi or libcxxrt to provide the ABI and runtime bits
of the C++ STL. However we also support building w/o an ABI library entirely.
This patch fixes building libc++ w/o an ABI library (and incorporates the
`~type_info()` fix in D28211).
The main changes in this patch are:
1) Add `-DLIBCXX_CXX_ABI=default` instead of using the empty string to mean "default".
2) Fix CMake bits which treated "none" as "default" on OS X.
3) Teach the source files to respect `-D_LIBCPP_BUILDING_HAS_NO_ABI_LIBRARY`.
4) Define ~type_info() when _LIBCPP_BUILDING_HAS_NO_ABI_LIBRARY is defined.
Unfortunately this patch doesn't help clean up the macro mess that we use to
configure for different ABI libraries.
llvm-svn: 290839
Move the windows specific macro definitions for compiling c++ into the
target. Add a number of newer options that are necessary to properly
build libc++ for windows. This ensures that we do not accidentally
autolink msvcprt (Microsoft's C++ runtime library), do not define linker
pragmas which are msvcprt specific, and do not accidentally encode the
incorrect version of the msvc compatibility version.
llvm-svn: 290837
This allows us to build with cl (or rather clang-cl) by using the
correct spelling for `-include` (`/FI` for cl). clang-cl and cl default
to C++11/C++14 as they support it rather than permitting an explicit
language standard.
llvm-svn: 290802
It's useful to be able to disable visibility annotations entirely; for
example, if we're building libc++ static to include in another library,
and we don't want any libc++ functions getting exported out of that
library. This is a generalization of _LIBCPP_DISABLE_DLL_IMPORT_EXPORT.
Differential Revision: https://reviews.llvm.org/D26934
llvm-svn: 288690
This patch adds a `check-cxx-abilist` target which verifies the libc++.so ABI
when the current build configuration matches the configuration used to generate
the ABI lists.
In order to make this change `HandleOutOfTreeLLVM.cmake` needed to be modified
to include `LLVMConfig.cmake` so that `TARGET_TRIPLE` is defined. Hopefully
the changes needed to accommodate this won't break existing build
configurations.
llvm-svn: 286789
The runtimes subdir is the new location for runtimes, we should
include it when looking for libcxxabi headers.
Differential Revision: https://reviews.llvm.org/D26363
llvm-svn: 286333
Summary:
This patch turns on `-fvisibility-inlines-hidden` when building the dylib. This is important so that libc++.dylib doesn't accidentally export inline-functions which are ODR used somewhere in the dylib.
On OS X this change has no effect on the current ABI of the dylib. Unfortunately on Linux there are already ~20 inline functions which are unintentionally exported by the dylib. Almost all of these are implicitly generated destructors. I believe removing these function definitions is safe because every "linkage unit" which uses these functions has its own definition, and therefore shouldn't be dependent on libc++.dylib to provide them.
Also could a FreeBSD maintainer comment on the ABI compatibility of this patch?
Reviewers: mclow.lists, emaste, dexonsmith, joker-eph-DISABLED, jroelofs, danalbert, mehdi_amini, compnerd, dim
Subscribers: beanz, mgorny, cfe-commits, modocache
Differential Revision: https://reviews.llvm.org/D25593
llvm-svn: 285101
musl's pthread implementations use volatile types in their structs
which is not being constexpr in C++11 but is in C++14.
Differential Revision: https://reviews.llvm.org/D25491
llvm-svn: 284950
Libc++ will not build with modules enabled. In order to support an in-tree
libc++ when LLVM_ENABLE_MODULES is ON we need to explicitly disable the feature.
Unfortunately the libc++ sources are fundamentally non-modular. For example
iostream.cpp defines cout, cerr, wout, ... as char buffers instead of streams
in order to better control initialization/destruction. Not shockingly Clang
diagnoses this. Many other sources files define _LIBCPP_BUILDING_FOO macros to
provide definitions for normally inline symbols (See bind.cpp). Finally The
current module.map prohibits using <strstream> in C++11 so we can't build
strstream.cpp.
I think I can fix most of these issues but until then just disable modules.
llvm-svn: 284230
Introduce LIBCXX_LIBRARIES_PUBLIC in addition to LIBCXX_LIBRARIES that
holds 'public' interface libraries -- that is, libraries that both
libc++ links to and programs linked against it need to link to.
Currently this includes the ABI library and optionally -lunwind (when
LIBCXXABI_USE_LLVM_UNWINDER is on). The libraries are included in the
linker script, in order to make it possible to link C++ programs using
clang with compiler-rt runtime out-of-the-box.
Differential Revision: https://reviews.llvm.org/D25008
llvm-svn: 283659
Revert r282483 as it causes build failures due to missing symbols when
not linking to -lgcc_s (i.e. doing pure LLVM stack build). The patch can
be reintroduced when the build system is fixed to add all needed
libraries (libunwind, compiler-rt).
llvm-svn: 282524
Louis Dionne