The GCC build failures have been addressed, and the LLDB failures were
fixed by LLDB.
I have also verified that the apple-clang 9.0 segfault no longer
occurs.
Original Message:
The external instantiation of std::string is a problem for libc++.
Additions and removals of inline functions in string can cause ABI
breakages, including introducing new symbols.
This patch aims to:
(1) Make clear which functions are explicitly instatiated.
(2) Prevent new functions from being accidentally instantiated.
(3) Allow a migration path for adding or removing functions from the
explicit instantiation over time.
Although this new formulation is uglier, it is preferable from a
maintainability and readability standpoint because it explicitly
enumerates the functions we've chosen to expose in our ABI. Changing
this list is non-trivial and requires thought and planning.
(3) is achieved by making it possible to control the extern template declaration
separately from it's definition. Meaning we could add a new definition to
the dylib, wait for it to roll out, then add the extern template
declaration to the header. Similarly, we could remove existing extern
template declarations while still keeping the definition to prevent ABI
breakages.
The external instantiation of std::string is a problem for libc++.
Additions and removals of inline functions in string can cause ABI
breakages, including introducing new symbols.
This patch aims to:
(1) Make clear which functions are explicitly instatiated.
(2) Prevent new functions from being accidentally instantiated.
(3) Allow a migration path for adding or removing functions from the
explicit instantiation over time.
Although this new formulation is uglier, it is preferable from a
maintainability and readability standpoint because it explicitly
enumerates the functions we've chosen to expose in our ABI. Changing
this list is non-trivial and requires thought and planning.
(3) is achieved by making it possible to control the extern template declaration
separately from it's definition. Meaning we could add a new definition to
the dylib, wait for it to roll out, then add the extern template
declaration to the header. Similarly, we could remove existing extern
template declarations while still keeping the definition to prevent ABI
breakages.
to reflect the new license. These used slightly different spellings that
defeated my regular expressions.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351648
Summary:
This patch refactors and tries to remove as much of the Windows support headers as possible. This is needed because they currently introduce super weird include cycles and dependencies between STL and libc headers.
The changes in this patch are:
* remove `support/win32/support.h` completely. The required parts have either been moved into `support/win32/msvc_support.h` (for `MSVC` only helpers not needed by Clang), or directly into their respective `foo.h` headers.
* Combine `locale_win32.h` and `locale_mgmt_win32.h` into a single headers, this header should only be included within `__locale` or `locale` to avoid include cycles.
* Remove the unneeded parts of `limits_win32.h` and re-name it to `limits_msvc_win32.h` since it's only needed by Clang.
I've tested this patch using Clang on Windows, but I suspect it might technically regress our non-existent support for MSVC. Is somebody able to double check?
This refactor is needed to support upcoming fixes to `<locale>` on Windows.
Reviewers: bcraig, rmaprath, compnerd, EricWF
Reviewed By: EricWF
Subscribers: majnemer, cfe-commits
Differential Revision: https://reviews.llvm.org/D32988
llvm-svn: 302727
These functions were removed from the dylib sometime between the 3.9 release
and now. This patch manually exports them to re-gain ABI compatibility.
llvm-svn: 284193
Summary:
This patch has been a long time coming (Thanks @eugenis). It changes `_LIBCPP_INLINE_VISIBILITY` to use `__attribute__((internal_linkage))` instead of `__attribute__((visibility("hidden"), always_inline))`.
The point of `_LIBCPP_INLINE_VISIBILITY` is to prevent inline functions from being exported from both the libc++ library and from user libraries. This helps libc++ better manage it's ABI.
Previously this was done by forcing inlining and modifying the symbols visibility. However inlining isn't guaranteed and symbol visibility only affects shared libraries making this an imperfect solution. `internal_linkage` improves this situation by making all symbols local to the TU they are emitted in, regardless of inlining or visibility. IIRC the effect of applying `__attribute__((internal_linkage))` to an inline function is the same as applying `static`.
For more information about the attribute see: http://lists.llvm.org/pipermail/cfe-dev/2015-October/045580.html
Most of the work for this patch was done by @eugenis.
Reviewers: mclow.lists, eugenis
Subscribers: eugenis, cfe-commits
Differential Revision: https://reviews.llvm.org/D24642
llvm-svn: 282345
On Windows, marking an `extern template class` declaration as exported
actually forces an instantiation, which is not the desired behavior.
Instead, the actual explicit instantiations need to be exported.
Differential Revision: https://reviews.llvm.org/D24679
llvm-svn: 281925
There are a couple of places where libc++ prints log/error messages to
stdout on its own. This may of course interfere with the output
generated with applications. Log/error messages should be directed to
stderr instead.
Differential Revision: http://reviews.llvm.org/D8135
Reviewed by: marshall
llvm-svn: 231767
Since the initialization of the pointer happens across the libc library boundry
MSAN will not know the pointer was initialized. This fixes MSAN failures in
test/strings/string.conversions.
llvm-svn: 222052
Turning off explicit template instantiation leads to a pretty
significant build time and code size cost. We're better off dealing
with ABI incompatibility issues that come up in a less heavy handed
way.
This reverts commit r189610.
llvm-svn: 215740
MSVC-specific, MSVCRT-specific, or Windows-specific. Because Clang can
also define _MSC_VER, and MSVCRT is not necessarily the only C runtime,
these macros should not be used interchangeably.
This patch divides all Windows-related bits into the aforementioned
categories. Two new macros are introduced:
- _LIBCPP_MSVC: Defined when compiling with MSVC. Detected using
_MSC_VER, excluding Clang.
- _LIBCPP_MSVCRT: Defined when using the Microsoft CRT. This is the default
when _WIN32 is defined.
This leaves _WIN32 for code using the Windows API.
This also corrects the spelling of _LIBCP_HAS_IS_BASE_OF to _LIBCPP_HAS_IS_BASE_OF.
Nico, please prepare a patch for CREDITS.TXT, thanks.
llvm-svn: 187593
template typename deductions on swap<> (used in string.cpp). Use
decltype(errno) to replicate the type and qualifier information for holding the
errno value. Because errno is expected to be assignable, there is no need to
use typename std::remove_const<decltype(errno)>::type to hold the value.
llvm-svn: 173172
Eric Fiselier