llvm-project/compiler-rt
Hans Wennborg 83ff22c297 Revert r348335 "[XRay] Move-only Allocator, FunctionCallTrie, and Array"
.. and also the follow-ups r348336 r348338.

It broke stand-alone compiler-rt builds with GCC 4.8:

In file included from /work/llvm/projects/compiler-rt/lib/xray/xray_function_call_trie.h:20:0,
                 from /work/llvm/projects/compiler-rt/lib/xray/xray_profile_collector.h:21,
                 from /work/llvm/projects/compiler-rt/lib/xray/xray_profile_collector.cc:15:
/work/llvm/projects/compiler-rt/lib/xray/xray_segmented_array.h: In instantiation of ‘T* __xray::Array<T>::AppendEmplace(Args&& ...) [with Args = {const __xray::FunctionCallTrie::mergeInto(__xray::FunctionCallTrie&) const::NodeAndTarget&}; T = __xray::FunctionCallTrie::mergeInto(__xray::FunctionCallTrie&) const::NodeAndTarget]’:
/work/llvm/projects/compiler-rt/lib/xray/xray_segmented_array.h:383:71:   required from ‘T* __xray::Array<T>::Append(const T&) [with T = __xray::FunctionCallTrie::mergeInto(__xray::FunctionCallTrie&) const::NodeAndTarget]’
/work/llvm/projects/compiler-rt/lib/xray/xray_function_call_trie.h:517:54:   required from here
/work/llvm/projects/compiler-rt/lib/xray/xray_segmented_array.h:378:5: error: could not convert ‘{std::forward<const __xray::FunctionCallTrie::mergeInto(__xray::FunctionCallTrie&) const::NodeAndTarget&>((* & args#0))}’ from ‘<brace-enclosed initializer list>’ to ‘__xray::FunctionCallTrie::mergeInto(__xray::FunctionCallTrie&) const::NodeAndTarget’
     new (AlignedOffset) T{std::forward<Args>(args)...};
     ^
/work/llvm/projects/compiler-rt/lib/xray/xray_segmented_array.h: In instantiation of ‘T* __xray::Array<T>::AppendEmplace(Args&& ...) [with Args = {const __xray::profileCollectorService::{anonymous}::ThreadTrie&}; T = __xray::profileCollectorService::{anonymous}::ThreadTrie]’:
/work/llvm/projects/compiler-rt/lib/xray/xray_segmented_array.h:383:71:   required from ‘T* __xray::Array<T>::Append(const T&) [with T = __xray::profileCollectorService::{anonymous}::ThreadTrie]’
/work/llvm/projects/compiler-rt/lib/xray/xray_profile_collector.cc:98:34:   required from here
/work/llvm/projects/compiler-rt/lib/xray/xray_segmented_array.h:378:5: error: could not convert ‘{std::forward<const __xray::profileCollectorService::{anonymous}::ThreadTrie&>((* & args#0))}’ from
‘<brace-enclosed initializer list>’ to ‘__xray::profileCollectorService::{anonymous}::ThreadTrie’
/work/llvm/projects/compiler-rt/lib/xray/xray_segmented_array.h: In instantiation of ‘T* __xray::Array<T>::AppendEmplace(Args&& ...) [with Args = {const __xray::profileCollectorService::{anonymous}::ProfileBuffer&}; T = __xray::profileCollectorService::{anonymous}::ProfileBuffer]’:
/work/llvm/projects/compiler-rt/lib/xray/xray_segmented_array.h:383:71:   required from ‘T* __xray::Array<T>::Append(const T&) [with T = __xray::profileCollectorService::{anonymous}::ProfileBuffer]
’
/work/llvm/projects/compiler-rt/lib/xray/xray_profile_collector.cc:244:44:   required from here
/work/llvm/projects/compiler-rt/lib/xray/xray_segmented_array.h:378:5: error: could not convert ‘{std::forward<const __xray::profileCollectorService::{anonymous}::ProfileBuffer&>((* & args#0))}’ from ‘<brace-enclosed initializer list>’ to ‘__xray::profileCollectorService::{anonymous}::ProfileBuffer’

> Summary:
> This change makes the allocator and function call trie implementations
> move-aware and remove the FunctionCallTrie's reliance on a
> heap-allocated set of allocators.
>
> The change makes it possible to always have storage associated with
> Allocator instances, not necessarily having heap-allocated memory
> obtainable from these allocator instances. We also use thread-local
> uninitialised storage.
>
> We've also re-worked the segmented array implementation to have more
> precondition and post-condition checks when built in debug mode. This
> enables us to better implement some of the operations with surrounding
> documentation as well. The `trim` algorithm now has more documentation
> on the implementation, reducing the requirement to handle special
> conditions, and being more rigorous on the computations involved.
>
> In this change we also introduce an initialisation guard, through which
> we prevent an initialisation operation from racing with a cleanup
> operation.
>
> We also ensure that the ThreadTries array is not destroyed while copies
> into the elements are still being performed by other threads submitting
> profiles.
>
> Note that this change still has an issue with accessing thread-local
> storage from signal handlers that are instrumented with XRay. We also
> learn that with the testing of this patch, that there will be cases
> where calls to mmap(...) (through internal_mmap(...)) might be called in
> signal handlers, but are not async-signal-safe. Subsequent patches will
> address this, by re-using the `BufferQueue` type used in the FDR mode
> implementation for pre-allocated memory segments per active, tracing
> thread.
>
> We still want to land this change despite the known issues, with fixes
> forthcoming.
>
> Reviewers: mboerger, jfb
>
> Subscribers: jfb, llvm-commits
>
> Differential Revision: https://reviews.llvm.org/D54989

llvm-svn: 348346
2018-12-05 10:19:55 +00:00
..
cmake [CMake] Add a missing case of TO_CMAKE_PATH 2018-11-27 09:23:15 +00:00
docs [sanitizers] Make it possible to XFAIL on the effective target, not just the default. 2016-08-09 11:50:53 +00:00
include Regenerate syscall hooks for NetBSD 8.99.25 2018-10-30 11:10:36 +00:00
lib Revert r348335 "[XRay] Move-only Allocator, FunctionCallTrie, and Array" 2018-12-05 10:19:55 +00:00
test [asan] Add clang flag -fsanitize-address-use-odr-indicator 2018-12-05 01:44:31 +00:00
unittests [XRay] Add LD_LIBRARY_PATH to env variables for Unit Tests 2018-09-27 23:15:05 +00:00
utils Update generate_netbsd_ioctls.awk for NetBSD 8.99.25 2018-10-31 12:52:08 +00:00
www
.arcconfig [compiler-rt] Set up .arcconfig to point to new Diffusion CRT repository 2017-12-06 20:55:32 +00:00
.gitignore Add .pyc files to .gitignore to compiler-rt 2017-07-24 21:51:12 +00:00
CMakeLists.txt [CMake] When built with LLVM, not use `-Wl,-z,defs` 2018-10-29 22:16:56 +00:00
CODE_OWNERS.TXT [sanitizers] remove earthdok@ from owners 2016-05-18 18:52:18 +00:00
CREDITS.TXT
LICENSE.TXT Update copyright year to 2018. 2018-06-18 12:22:17 +00:00
README.txt

README.txt

Compiler-RT
================================

This directory and its subdirectories contain source code for the compiler
support routines.

Compiler-RT is open source software. You may freely distribute it under the
terms of the license agreement found in LICENSE.txt.

================================