Commit Graph

279 Commits

Author SHA1 Message Date
Louis Dionne 9b40ee8eb0 [libc++] Define new/delete in libc++abi only by default
Previously, we would define new/delete in both libc++ and libc++abi.
Not only does this cause code bloat, but also it's technically an ODR
violation since we don't know which operator will be selected. Furthermore,
since those are weak definitions, we should strive to have as few of them
as possible (to improve load times).

My preferred choice would have been to put the operators in libc++ only
by default, however that would create a circular dependency between
libc++ and libc++abi, which GNU linkers don't handle.

Folks who want to ship new/delete in libc++ instead of libc++abi are
free to do so by turning on LIBCXX_ENABLE_NEW_DELETE_DEFINITIONS at
CMake configure time.

On Apple platforms, this shouldn't be an ABI break because we re-export
the new/delete symbols from libc++abi. This change actually makes libc++
behave closer to the system libc++ shipped on Apple platforms.

On other platforms, this is an ABI break for people linking against libc++
but not libc++abi. However, vendors have been consulted in D68269 and no
objection was raised. Furthermore, the definitions can be controlled to
appear in libc++ instead with the CMake option.

Differential Revision: https://reviews.llvm.org/D68269
2020-10-19 11:35:01 -04:00
Louis Dionne d5a6da84a3 [libc++/abi] Revert "[libc++] Move the weak symbols list to libc++abi"
This reverts commit c7d4aa711a. I am still investigating the issue,
but it looks like that commit has an interaction with ld64 that causes
new/delete weak re-exports not to work properly anymore. This is weird
because this commit did not touch the exports of new/delete -- I am
still investigating.
2020-10-05 11:42:13 -04:00
Louis Dionne c7d4aa711a [libc++] Move the weak symbols list to libc++abi
Those symbols are exported from libc++abi in the first place, so it
makes more sense to have them there.
2020-10-02 09:22:23 -04:00
Louis Dionne a0119e5675 [libc++] NFC: Add missing SHA to ABI Changelog 2020-10-01 13:40:13 -04:00
Louis Dionne 4f13b99929 [libc++] Simplify how we re-export symbols from libc++abi
Instead of managing two copies of the symbol lists, reuse the same list
in libc++abi and libc++.

Differential Revision: https://reviews.llvm.org/D88623
2020-10-01 08:30:27 -04:00
Louis Dionne 490b556a0f [libc++] Make sure we don't attempt to run check-cxx-abilist when libc++ doesn't define new/delete
That would make the test fail spuriously because we don't generate
an ABI list for that configuration.
2020-09-30 14:59:03 -04:00
Martijn Vels 2bad222680 Add optimization to basic_string::assign for compile-time known constant values.
Summary:
This change optimizes the assign() methods for string where either the contents or lengths are compile time known constants. For small strings (< min_cap) we can execute the assignment entirely inline. For strings up to 128 bytes we allow the compiler to efficiently inline the copy operation after we call the offline __resize<>() method. Short / long branches are taken at the call site for better branch prediction and allowing FDO optimizations.

Benchmarks (unstable / google perflab):
```
name                                                old time/op             new time/op             delta
BM_StringAssignAsciiz_Empty_Opaque                  5.69ns ± 7%             5.97ns ± 7%     ~             (p=0.056 n=5+5)
BM_StringAssignAsciiz_Empty_Transparent             5.39ns ± 7%             0.79ns ± 8%  -85.36%          (p=0.008 n=5+5)
BM_StringAssignAsciiz_Small_Opaque                  11.2ns ± 5%             11.0ns ± 6%     ~             (p=0.548 n=5+5)
BM_StringAssignAsciiz_Small_Transparent             10.1ns ± 7%              1.0ns ± 8%  -89.76%          (p=0.008 n=5+5)
BM_StringAssignAsciiz_Large_Opaque                  23.5ns ± 7%             23.8ns ± 7%     ~             (p=0.841 n=5+5)
BM_StringAssignAsciiz_Large_Transparent             21.4ns ± 7%             12.7ns ± 7%  -40.83%          (p=0.008 n=5+5)
BM_StringAssignAsciiz_Huge_Opaque                    336ns ± 4%              327ns ± 7%     ~             (p=0.421 n=5+5)
BM_StringAssignAsciiz_Huge_Transparent               331ns ± 5%              324ns ± 7%     ~             (p=0.548 n=5+5)
BM_StringAssignAsciizMix_Opaque                     13.6ns ±10%             13.7ns ± 9%     ~             (p=0.690 n=5+5)
BM_StringAssignAsciizMix_Transparent                12.9ns ± 8%              3.6ns ± 8%  -71.82%          (p=0.008 n=5+5)
```

Reviewers: EricWF, #libc!

Subscribers: jfb, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D82221
2020-06-29 14:34:34 -04:00
Louis Dionne ecf313c01d [libc++] Fix the no-exceptions build of libc++ on Apple
We previously tried re-exporting symbols that didn't exist when
exceptions were disabled. Note that building libc++abi without
exceptions still doesn't work when linking against the default-provided
libSystem.dylib, because it transitively depends on libobjc.dylib,
and that requires __gxx_personality_v0. But building libc++abi
with exceptions and libc++ without exceptions does work.
2020-04-20 10:45:14 -04:00
Louis Dionne d34241a89d [libc++] Add SHA for C++20 Synchronization Library in ABI changelog
This is mostly a means to test a new Herald rule for libc++ reviews.

Differential Revision: https://reviews.llvm.org/D76022
2020-03-11 16:13:13 -04:00
Louis Dionne b21405d1cd [libc++] Fix CI and Linux failures after landing D68480
- Avoid using C++11-and-later features in <atomic>:
  Historically, we've supported <atomic> in C++03, so we can't use C++11
  features in that header. This is something we really need to change,
  since our implementation of <atomic> is starting to accumulate technical
  debt because of that.
- Mark a test as unsupported on single threaded systems
- Add missing symbols to the Linux ABI list
2020-02-24 11:58:25 -05:00
Louis Dionne 80e73f2295 [libc++] Adapt a few things around the implementation of P1135R6
- Add the new symbols to the ABI list on Darwin
- Add XFAIL markup to the tests that require dylib support on older platforms
- Add availability markup for back-deployment
2020-02-24 10:59:35 -05:00
Louis Dionne 5e52effca6 [libc++] Add ABI list for 9.0 release
I just took a snapshot of the current ABI lists on master, since I don't
think they changed since the actual 9.0 release.
2020-02-18 10:50:49 -05:00
Louis Dionne 0961a152d8 [libc++] Add missing revision number in ABI changelog
llvm-svn: 373625
2019-10-03 16:50:05 +00:00
Louis Dionne be8c669af0 [libc++] Update ABI list for ABI v2
I forgot to add symbols for filesystem.

llvm-svn: 363603
2019-06-17 19:37:26 +00:00
Petr Hosek f80c4b6348 [libcxx] Move CMake file to src, avoid using globs
This addresses the longstanding FIXME and makes libc++ build more
similar to other runtimes.

Differential Revision: https://reviews.llvm.org/D61275

llvm-svn: 359656
2019-05-01 06:40:36 +00:00
Louis Dionne 68924e6be7 [libc++][CMake] Refactor how we link against system libraries
Summary:
Instead of populating the global LIBCXX_LIBRARIES, we use the link-time
dependency management built into CMake to propagate link flags. This
leads to a cleaner and easier-to-follow build.

Reviewers: phosek, smeenai, EricWF

Subscribers: mgorny, christof, jkorous, dexonsmith, jfb, mstorsjo, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D60969

llvm-svn: 359571
2019-04-30 15:44:19 +00:00
Richard Smith de329354aa Remove incorrect explicit instantiation declarations for valarray
libc++ ABI v1 provides three valarray symbols as part of the shared library:

valarray<size_t>::valarray(size_t)
valarray<size_t>::~valarray()
valarray<size_t>::resize(size_t, size_t)

The first two of these are intended to be removed in V2 of the ABI: they're
attributed _LIBCPP_HIDE_FROM_ABI_AFTER_V1, and  it appears that the intention
is that these symbols from the library are not used even when building using
the V1 ABI. However, there are explicit instantiation declarations for all
three symbols in the header, which are not correct as we do not intend to find
an instantiation of these functions that is provided elsewhere.

(A recent change to clang to properly diagnose explicit instantiation
declarations of internal linkage functions -- required by [temp.explicit]p13 --
had to be rolled back because it diagnosed these explicit instantiations.)

Remove the explicit instantiation declarations, and remove the explicit
instantiation definitions for V2 of the libc++ ABI onwards.

llvm-svn: 359243
2019-04-25 21:31:58 +00:00
Petr Hosek e9a2d1c392 [libcxx] Update gen_link_script.py to support different input and output
This enables the use of this script from other build systems like
GN which don't support post-build actions as well as for static
archives.

Differential Revision: https://reviews.llvm.org/D60309

llvm-svn: 358915
2019-04-22 19:51:33 +00:00
Louis Dionne 549048f390 [libc++] Make sure we re-export some missing libc++abi symbols from libc++
Summary:
Ensure we re-export __cxa_throw_bad_array_new_length and
__cxa_uncaught_exceptions from libc++, since they are now
provided by libc++abi.

Doing this allows us to stop linking explicitly against libc++abi in
the libc++abi tests, since libc++ re-exports all the necessary symbols.
However, there is one caveat to that. We don't want libc++ to re-export
__cxa_uncaught_exception (the singular form), since it's only provided
for backwards compatibility. Hence, for the single test where we check
this backwards compatibility, we explicitly link against libc++abi.

PR27405
PR22654

Reviewers: EricWF

Subscribers: christof, jkorous, dexonsmith, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D60424

llvm-svn: 358690
2019-04-18 17:18:15 +00:00
Petr Hosek 1788b89b4f [CMake] Split linked libraries for shared and static libc++
Some linker libraries are only needed for shared libc++, some only
for static libc++, combining these together in LIBCXX_LIBRARIES and
LIBCXX_INTERFACE_LIBRARIES can introduce unnecessary dependencies.

This changes splits those up into LIBCXX_SHARED_LIBRARIES and
LIBCXX_STATIC_LIBRARIES matching what libc++abi already does.

Differential Revision: https://reviews.llvm.org/D57872

llvm-svn: 358614
2019-04-17 21:41:09 +00:00
Louis Dionne 5e165fba3a [NFC] Add missing revision number in libc++ ABI changelog
llvm-svn: 358411
2019-04-15 14:29:33 +00:00
Martin Storsjo c90045bf10 [CMake] Fix statically linking in libcxxabi if built separately
In this case, CMake doesn't know about the c++abi target within the
same CMake run.

This reverts this aspect back to how it was before SVN r357811.

Differential Revision: https://reviews.llvm.org/D60448

llvm-svn: 358009
2019-04-09 14:31:09 +00:00
Louis Dionne fecbf5918b [libc++] Remove install_name and compatibility_version on OS X
CMake already specifies those, and we never actually want those to be
used. In fact, r357811 re-ordered those flags in a way that the
explicitly-provided install_name was overriding the CMake-provided
install_name (instead of the other way around). This caused the dylib
to be considered a system dylib, and hence the explicitly provided rpath
to be ignored. This, in turn, caused some unit tests to start linking
against the system libc++.dylib instead of the freshly-built one.
Specifically, the unit tests that started linking against the system
dylib are those that didn't specify a DYLD_LIBRARY_PATH, such as
last_write_time.sh.cpp.

llvm-svn: 357946
2019-04-08 21:37:42 +00:00
Louis Dionne cd9a528886 [libc++][CMake] Make sure the benchmarks link against libc++abi
The refactoring in r357811 made it so that we didn't add the ABI library
to the list of LIBCXX_LIBRARIES. As a result, benchmarks didn't link to
the ABI library and were missing symbols. This broke the build bots.

As a drive-by fix, we also provide the SHARED ABI library to the linker
script instead of the STATIC ABI library.

This couldn't be discovered on Apple platforms because libc++.dylib
re-exports libc++abi.dylib symbols there.

llvm-svn: 357818
2019-04-05 21:05:32 +00:00
Louis Dionne 6e68a79110 [libc++] Localize CMake code only related to the shared library
Summary:
There's a lot of CMake logic that's only relevant to the shared library,
yet it was using a code path and setting variables that impact both the
shared and the static libraries. This patch moves this logic so that it
clearly only impacts the shared library.

Reviewers: phosek, smeenai, EricWF

Subscribers: mgorny, christof, jkorous, dexonsmith, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D60276

llvm-svn: 357811
2019-04-05 20:29:54 +00:00
Petr Hosek 30d9af1b24 [CMake] Differentiate between static and shared libc++abi
This addresses the issue introduced in r354212 which broke the case when
static libc++abi is merged into static libc++, but shared libc++ is
linked against shared libc++. There are 4 different possible
combinations which is difficult to capture using a single variable. This
change splits LIBCXX_CXX_ABI_LIBRARY into two:
LIBCXX_CXX_SHARED_ABI_LIBRARY and LIBCXX_CXX_STATIC_ABI_LIBRARY to
handle the shared and static cases. This in turn allows simplification
of some of the logic around merging of static archives.

Differential Revision: https://reviews.llvm.org/D60114

llvm-svn: 357556
2019-04-03 01:33:14 +00:00
Louis Dionne 976073794e [libc++][CMake] Allow merging libc++abi.a into libc++ even on Apple platforms
Summary:
I can't see a good reason to disallow this, even though it isn't the
standard way we build libc++ for Apple platforms.

Making this work on Apple platforms requires using different flags for
--whole-archive and removing the -D flag when running `ar` to merge
archives because that flag isn't supported by the `ar` shipped on Apple
platforms. This shouldn't be an issue since the -D option appears to be
enabled by default in GNU `ar`.

Reviewers: phosek, EricWF, serge-sans-paille

Subscribers: mgorny, christof, jkorous, dexonsmith, libcxx-commits

Differential Revision: https://reviews.llvm.org/D59513

llvm-svn: 356903
2019-03-25 14:56:29 +00:00
Louis Dionne c48e223309 [libc++] Update the list of symbols exported from libc++abi for new/delete
When libc++ does not provide new/delete, libc++abi now also provides the
aligned allocation and deallocation functions, so those should be part of
the re-export list for libc++.

llvm-svn: 356804
2019-03-22 20:18:17 +00:00
Louis Dionne 5934341fd9 [libc++] Re-export the sjlj ABI v2 for ARM architectures
We were previously not exporting the right ABI version of libc++abi.

llvm-svn: 356798
2019-03-22 19:38:53 +00:00
Eric Fiselier f1d87f8b4c Allow disabling of filesystem library.
Summary: Filesystem doesn't work on Windows, so we need a mechanism to turn it off for the time being.

Reviewers: ldionne, serge-sans-paille, EricWF

Reviewed By: EricWF

Subscribers: mstorsjo, mgorny, christof, jdoerfert, libcxx-commits

Differential Revision: https://reviews.llvm.org/D59619

llvm-svn: 356633
2019-03-21 00:04:31 +00:00
Louis Dionne 2d0b4d6bb3 [libc++][CMake] Clean up some of the libc++ re-exporting logic
Summary:
This change allows specifying the version of libc++abi's ABI to re-export
when configuring CMake. It also clearly identifies which ABI version of
libc++abi each export file contains.

Finally, it removes hardcoded knowledge about the 10.9 SDK for MacOS,
since that knowledge is not relevant anymore. Indeed, libc++ can't be
built with the toolchain that came with the 10.9 SDK anyway because
the version of Clang it includes is too old (for example if you want
to build a working libc++.dylib, you need bugfixes to visibility
attributes that are only in recent Clangs).

Reviewers: dexonsmith, EricWF

Subscribers: mgorny, christof, jkorous, arphaman, libcxx-commits

Differential Revision: https://reviews.llvm.org/D59489

llvm-svn: 356587
2019-03-20 18:16:24 +00:00
Louis Dionne 2b27c00102 [libc++] Complete the ABI changelog after landing <filesystem> in the dylib
llvm-svn: 356523
2019-03-19 21:32:37 +00:00
Louis Dionne cc37af7a36 [libc++] Build <filesystem> support as part of the dylib
Summary:
This patch treats <filesystem> as a first-class citizen of the dylib,
like all other sub-libraries (e.g. <chrono>). As such, it also removes
all special handling for installing the filesystem library separately
or disabling part of the test suite from the lit command line.

Unlike the previous attempt (r356500), this doesn't remove all the
filesystem tests.

Reviewers: mclow.lists, EricWF, serge-sans-paille

Subscribers: mgorny, christof, jkorous, dexonsmith, jfb, jdoerfert, libcxx-commits

Differential Revision: https://reviews.llvm.org/D59152

llvm-svn: 356518
2019-03-19 20:56:13 +00:00
Louis Dionne f7b43230b8 Revert "[libc++] Build <filesystem> support as part of the dylib"
When I applied r356500 (https://reviews.llvm.org/D59152), I somehow
deleted all of filesystem's tests. I will revert r356500 and re-apply
it properly.

llvm-svn: 356505
2019-03-19 19:27:29 +00:00
Eric Fiselier 9b7685d545 Fixup ABI lists on Linux after adding <filesystem> to the dylib.
llvm-svn: 356503
2019-03-19 19:20:43 +00:00
Louis Dionne 72122d058b [libc++] Build <filesystem> support as part of the dylib
Summary:
This patch treats <filesystem> as a first-class citizen of the dylib,
like all other sub-libraries (e.g. <chrono>). As such, it also removes
all special handling for installing the filesystem library separately
or disabling part of the test suite from the lit command line.

Reviewers: mclow.lists, EricWF, serge-sans-paille

Subscribers: mgorny, christof, jkorous, dexonsmith, jfb, jdoerfert, libcxx-commits

Differential Revision: https://reviews.llvm.org/D59152

llvm-svn: 356500
2019-03-19 19:09:33 +00:00
Eric Fiselier 61b302f94f Remove exception throwing debug mode handler support.
Summary:
The reason libc++ implemented a throwing debug mode handler was for ease of testing. Specifically,
I thought that if a debug violation aborted, we could only test one violation per file. This made
it impossible to test debug mode. Which throwing behavior we could test more!

However, the throwing approach didn't work either, since there are debug violations underneath noexcept
functions. This lead to the introduction of `_NOEXCEPT_DEBUG`, which was only noexcept when debug
mode was off.

Having thought more and having grown wiser, `_NOEXCEPT_DEBUG` was a horrible decision. It was
viral, it didn't cover all the cases it needed to, and it was observable to the user -- at worst
changing the behavior of their program.

  This patch removes the throwing debug handler, and rewrites the debug tests using 'fork-ing' style
  death tests.

Reviewers: mclow.lists, ldionne, thomasanderson

Reviewed By: ldionne

Subscribers: christof, arphaman, libcxx-commits, #libc

Differential Revision: https://reviews.llvm.org/D59166

llvm-svn: 356417
2019-03-18 21:50:12 +00:00
Louis Dionne 702411fc29 [libc++][CMake] Do not define `cxx_shared_EXPORTS` when building the shared library
CMake will define -Dcxx_shared_EXPORTS when building the shared library
by default. In theory, this is used to signal to the library that we're
building a shared library and that dllimport/dllexport should be used.
However, we already have our own way of doing that, so I'm removing this
define to avoid meaningless command line arguments in the build.

llvm-svn: 356167
2019-03-14 17:15:47 +00:00
Louis Dionne 850a3d3b92 [libc++][CMake] Fix typo introduced in r356150
That typo broke the build when the shared library build was disabled.

llvm-svn: 356155
2019-03-14 14:52:26 +00:00
Louis Dionne 30f305efe2 [libc++] Do not force building with -fPIC (re-applying)
Summary:
In r355746, we stopped forcing to build with -fPIC because that should
be specified by the CMAKE_POSITION_INDEPENDENT_CODE option at CMake
configure time (and by default -fPIC is used for shared libraries anyways).

However, r355746 had to be reverted in r355756 because we were not
actually building the shared library with -fPIC. The reason is that
we were sharing an object library between the static and the shared
library, which caused flags for static libraries to be used when
building object files that were going to be used for a shared library.

Since this was resolved by r356150, we can stop forcing -fPIC again.

Reviewers: EricWF, smeenai

Subscribers: mgorny, christof, jkorous, dexonsmith, libcxx-commits

Differential Revision: https://reviews.llvm.org/D59250

llvm-svn: 356153
2019-03-14 14:38:38 +00:00
Louis Dionne 989eca62c6 [libc++] Do not share an object library to create the static/shared libraries
Summary:
The problem with using an object library for doing this is that it prevents
the shared library and the static library from being built with the right
default flags. For example, CMake will build shared libraries with -fPIC
by default, but not static libraries. Using an object library to create
the shared library will prevent the right default flags for shared
libraries from being used.

As a side effect, this patch also localizes the logic related to building
a hermetic static library to the static library case, making clear that
this has no effect on the shared library.

Reviewers: phosek, EricWF

Subscribers: mgorny, christof, jkorous, dexonsmith, jdoerfert, libcxx-commits

Differential Revision: https://reviews.llvm.org/D59248

llvm-svn: 356150
2019-03-14 14:19:08 +00:00
Eric Fiselier 9dd9495a35 Revert "[libc++] Do not force building with -fPIC"
This reverts commit r355764.

CMake does not turn -fPIC on for us by default. so this patch breaks
standalone builds. The only reason it hasn't broken any bots is because
LLVM turns on and specifies '-fPIC' for us.

llvm-svn: 355756
2019-03-08 23:27:46 +00:00
Louis Dionne 2714d58901 [libc++] Do not force building with -fPIC
Summary:
Whether we build with -fPIC should be specified by the
CMAKE_POSITION_INDEPENDENT_CODE option at configure time.
Note that this patch doesn't change the behavior when building
by default, since -fPIC is used for shared libraries by default.

Reviewers: EricWF

Subscribers: mgorny, christof, jkorous, dexonsmith, libcxx-commits

Differential Revision: https://reviews.llvm.org/D59146

llvm-svn: 355746
2019-03-08 22:24:12 +00:00
Louis Dionne 3d678b5336 [NFC] Add missing revision information to ABI Changelog
llvm-svn: 355732
2019-03-08 21:01:25 +00:00
Matthew Voss 1262e52e16 Revert "[runtimes] Move libunwind, libc++abi and libc++ to lib/ and include/"
This broke the windows bots.

This reverts commit 28302c66d2.

llvm-svn: 355725
2019-03-08 20:33:55 +00:00
Petr Hosek 28302c66d2 [runtimes] Move libunwind, libc++abi and libc++ to lib/ and include/
This change is a consequence of the discussion in "RFC: Place libs in
Clang-dedicated directories", specifically the suggestion that
libunwind, libc++abi and libc++ shouldn't be using Clang resource
directory.  Tools like clangd make this assumption, but this is
currently not true for the LLVM_ENABLE_PER_TARGET_RUNTIME_DIR build.
This change addresses that by moving the output of these libraries to
lib/<target> and include/ directories, leaving resource directory only
for compiler-rt runtimes and Clang builtin headers.

Differential Revision: https://reviews.llvm.org/D59013

llvm-svn: 355665
2019-03-08 05:35:22 +00:00
Eric Fiselier 1c014d75b4 Fix -fsanitize=vptr badness in <__debug>
Summary:

This patch fixes a lifetime bug when inserting a new container into the debug database. It is
diagnosed by UBSAN when debug mode is enabled. This patch corrects how nodes are constructed
during insertion.

The fix requires unconditionally breaking the debug mode ABI. Users should not expect ABI
stability from debug mode.

Reviewers: ldionne, serge-sans-paille, EricWF

Reviewed By: EricWF

Subscribers: mclow.lists, christof, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D58011

llvm-svn: 355367
2019-03-05 02:10:31 +00:00
Louis Dionne fc778fa2c5 [libc++] Remove old CMake workaround
We haven't had any complaints so far, and I don't think anybody builds
libc++ from source for that old platform anymore.

llvm-svn: 355336
2019-03-04 20:52:14 +00:00
Eric Fiselier 9d487c7d1e Make LIBCXX_STANDARD_VER configurable
llvm-svn: 353649
2019-02-10 18:27:55 +00:00
Eric Fiselier 609d676aab Format sym_extract.py output to minimize diff output.
Different versions of python print dictionaries in different orders.
 This can mess up diffs when updating ABI lists. This patch uses
 pprint.pformat to print the dicts to get a consistent ordering.

llvm-svn: 353634
2019-02-10 04:48:54 +00:00