[LLD][COFF] When using LLD-as-a-library, always prevent re-entrance on failures

This is a follow-up for D70378 (Cover usage of LLD as a library).

While debugging an intermittent failure on a bot, I

[LLD][COFF] When using LLD-as-a-library, always prevent re-entrance on failures

This is a follow-up for D70378 (Cover usage of LLD as a library).

While debugging an intermittent failure on a bot, I recalled this scenario which
causes the issue:

1.When executing lld/test/ELF/invalid/symtab-sh-info.s L45, we reach
lld::elf::Obj-File::ObjFile() which goes straight into its base ELFFileBase(),
then ELFFileBase::init().
2.At that point fatal() is thrown in lld/ELF/InputFiles.cpp L381, leaving a
half-initialized ObjFile instance.
3.We then end up in lld::exitLld() and since we are running with LLD_IN_TEST, we
hapily restore the control flow to CrashRecoveryContext::RunSafely() then back
in lld::safeLldMain().
4.Before this patch, we called errorHandler().reset() just after, and this
attempted to reset the associated SpecificAlloc<ObjFile<ELF64LE>>. That tried
to free the half-initialized ObjFile instance, and more precisely its
ObjFile::dwarf member.

Sometimes that worked, sometimes it failed and was catched by the
CrashRecoveryContext. This scenario was the reason we called
errorHandler().reset() through a CrashRecoveryContext.

But in some rare cases, the above repro somehow corrupted the heap, creating a
stack overflow. When the CrashRecoveryContext's filter (that is,
__except (ExceptionFilter(GetExceptionInformation()))) tried to handle the
exception, it crashed again since the stack was exhausted -- and that took the
whole application down. That is the issue seen on the bot. Locally it happens
about 1 times out of 15.

Now this situation can happen anywhere in LLD. Since catching stack overflows is
not a reliable scenario ATM when using CrashRecoveryContext, we're now
preventing further re-entrance when such failures occur, by signaling
lld::SafeReturn::canRunAgain=false. When running with LLD_IN_TEST=2 (or above),
only one iteration will be executed, instead of two.

Differential Revision: https://reviews.llvm.org/D88348

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[Support] On Unix, let the CrashRecoveryContext return the signal code

Before this patch, the CrashRecoveryContext was returning -2 upon a signal, like ExecuteAndWait does. This didn't match the beh

[Support] On Unix, let the CrashRecoveryContext return the signal code

Before this patch, the CrashRecoveryContext was returning -2 upon a signal, like ExecuteAndWait does. This didn't match the behavior on Windows, where the the exception code was returned.

We now return the signal's code, which optionally allows for re-throwing the signal later. Doing so requires all custom handlers to be removed first, through llvm::sys::unregisterHandlers() which we made a public API.

This is part of https://reviews.llvm.org/D70378

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[Support] On Windows, ensure abort() can be catched several times in a row with CrashRecoveryContext

Before this patch, the CrashRecoveryContext would only catch the first abort(). Any further calls

[Support] On Windows, ensure abort() can be catched several times in a row with CrashRecoveryContext

Before this patch, the CrashRecoveryContext would only catch the first abort(). Any further calls to abort() inside subsquent CrashRecoveryContexts would not be catched. This is because the Windows CRT removes the abort() handler before calling it.

This is part of https://reviews.llvm.org/D70378

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[SystemZ/ZOS] Add header file to encapsulate use of <sysexits.h>

The non-standard header file `<sysexits.h>` provides some return values.
`EX_IOERR` is used to as a special value to signal a broken

[SystemZ/ZOS] Add header file to encapsulate use of <sysexits.h>

The non-standard header file `<sysexits.h>` provides some return values.
`EX_IOERR` is used to as a special value to signal a broken pipe to the clang driver.
On z/OS Unix System Services, this header file does not exists. This patch

- adds a check for `<sysexits.h>`, removing the dependency on `LLVM_ON_UNIX`
- adds a new header file `llvm/Support/ExitCodes`, which either includes
`<sysexits.h>` or defines `EX_IOERR`
- updates the users of `EX_IOERR` to include the new header file

Reviewed By: hubert.reinterpretcast

Differential Revision: https://reviews.llvm.org/D83472

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llvm-ar: Fix MinGW compilation

llvm-ar is using CompareStringOrdinal which is available
only starting with Windows Vista (WINVER 0x600).

Fix this by hoising WindowsSupport.h, which sets _WIN32_WINN

llvm-ar: Fix MinGW compilation

llvm-ar is using CompareStringOrdinal which is available
only starting with Windows Vista (WINVER 0x600).

Fix this by hoising WindowsSupport.h, which sets _WIN32_WINNT
to 0x0601, up to llvm/include/llvm/Support and use it in llvm-ar.

Patch by Cristian Adam!

Differential revision: https://reviews.llvm.org/D74599

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Fix MSVC build with C++ EH enabled

Mark the CrashRecoveryContextImpl constructor noexcept, so that MSVC
won't emit an unwind helper to clean up the allocation from `new` if the
constructor throws an

Fix MSVC build with C++ EH enabled

Mark the CrashRecoveryContextImpl constructor noexcept, so that MSVC
won't emit an unwind helper to clean up the allocation from `new` if the
constructor throws an exception.

Otherwise, MSVC complains:
llvm\lib\Support\CrashRecoveryContext.cpp(220): error C2712: \
Cannot use __try in functions that require object unwinding

The other simple fix would be to wrap `new` in a static helper or
lambda.

Users have reported that Tensorflow builds LLVM with /EHsc.

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[Clang][Driver] After default -fintegrated-cc1, make llvm::report_fatal_error() generate preprocessed source + reproducer.sh again.

Added a test for #pragma clang __debug llvm_fatal_error to test fo

[Clang][Driver] After default -fintegrated-cc1, make llvm::report_fatal_error() generate preprocessed source + reproducer.sh again.

Added a test for #pragma clang __debug llvm_fatal_error to test for the original issue.
Added llvm::sys::Process::Exit() and replaced ::exit() in places where it was appropriate. This new function would call the current CrashRecoveryContext if one is running on the same thread; or call ::exit() otherwise.

Fixes PR44705.

Differential Revision: https://reviews.llvm.org/D73742

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[Support] When using SEH, create a impl instance for CrashRecoveryContext. NFCI.

Previously, the SEH codepath in CrashRecoveryContext didn't create a CrashRecoveryContextImpl. The other codepaths (V

[Support] When using SEH, create a impl instance for CrashRecoveryContext. NFCI.

Previously, the SEH codepath in CrashRecoveryContext didn't create a CrashRecoveryContextImpl. The other codepaths (VEH and Unix) were creating it.

When running with -fintegrated-cc1, this is needed to handle exit() as a jump to CrashRecoveryContext's exception filter, through a call to RaiseException. In that situation, we need a user-defined exception code, which is later interpreted as an exit() by the exception filter. This in turn needs to set RetCode accordingly, *inside* the exception filter, and *before* calling HandleCrash().

Differential Revision: https://reviews.llvm.org/D74078

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[Clang] Remove unused #pragma clang __debug handle_crash

As discussed in D70568, remove this because it isn't used anywhere, and I think it's better to go through real crashes for testing (#pragma c

[Clang] Remove unused #pragma clang __debug handle_crash

As discussed in D70568, remove this because it isn't used anywhere, and I think it's better to go through real crashes for testing (#pragma clang __debug crash).
Also remove the support function llvm::CrashRecoveryContext::HandleCrash() which was added at the same time by @ddunbar.

Differential Revision: https://reviews.llvm.org/D74063

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Work around PR44697 in CrashRecoveryContext

[NFC] Fix compilation of CrashRecoveryContext.cpp on mingw

Patch by Markus Böck.

Differential Revision: https://reviews.llvm.org/D72564

[Support] Optionally call signal handlers when a function wrapped by the the CrashRecoveryContext fails

This patch allows for handling a failure inside a CrashRecoveryContext in the same way as the

[Support] Optionally call signal handlers when a function wrapped by the the CrashRecoveryContext fails

This patch allows for handling a failure inside a CrashRecoveryContext in the same way as the global exception/signal handler. A failure will have the same side-effect, such as cleanup of temporarty file, printing callstack, calling relevant signal handlers, and finally returning an exception code. This is an optional feature, disabled by default.
This is a support patch for D69825.

Differential Revision: https://reviews.llvm.org/D70568

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Revert "Forward declare Optional<T> in STLExtras.h"

This reverts commit a36f316390d4bc1bcb0e9de0f55831385ab24099.

I did not intend to push this with the InitializePasses.h change.

Forward declare Optional<T> in STLExtras.h

WIP stats

minor doc typo fix / testing github commit

Reland "[Support] Add a way to run a function on a detached thread""

This reverts commit 7bc7fe6b789d25d48d6dc71d533a411e9e981237.
The immediate callers have been fixed to pass nullopt where appropr

Reland "[Support] Add a way to run a function on a detached thread""

This reverts commit 7bc7fe6b789d25d48d6dc71d533a411e9e981237.
The immediate callers have been fixed to pass nullopt where appropriate.

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[Support] Replace sys::Mutex with their standard equivalents.

Only use a recursive mutex if it can be locked recursively.

llvm-svn: 369295

Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the ne

Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

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: 351636

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Remove trailing space

sed -Ei 's/[[:space:]]+$//' include/**/*.{def,h,td} lib/**/*.{cpp,h}

llvm-svn: 338293

Remove \brief commands from doxygen comments.

We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they ar

Remove \brief commands from doxygen comments.

We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.

Patch produced by

for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done

Differential Revision: https://reviews.llvm.org/D46290

llvm-svn: 331272

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IWYU for llvm-config.h in llvm, additions.

See r331124 for how I made a list of files missing the include.
I then ran this Python script:

for f in open('filelist.txt'):
f = f.strip()

IWYU for llvm-config.h in llvm, additions.

See r331124 for how I made a list of files missing the include.
I then ran this Python script:

for f in open('filelist.txt'):
f = f.strip()
fl = open(f).readlines()

found = False
for i in xrange(len(fl)):
p = '#include "llvm/'
if not fl[i].startswith(p):
continue
if fl[i][len(p):] > 'Config':
fl.insert(i, '#include "llvm/Config/llvm-config.h"\n')
found = True
break
if not found:
print 'not found', f
else:
open(f, 'w').write(''.join(fl))

and then looked through everything with `svn diff | diffstat -l | xargs -n 1000 gvim -p`
and tried to fix include ordering and whatnot.

No intended behavior change.

llvm-svn: 331184

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s/LLVM_ON_WIN32/_WIN32/, llvm

LLVM_ON_WIN32 is set exactly with MSVC and MinGW (but not Cygwin) in
HandleLLVMOptions.cmake, which is where _WIN32 defined too. Just use the
default macro instead of

s/LLVM_ON_WIN32/_WIN32/, llvm

LLVM_ON_WIN32 is set exactly with MSVC and MinGW (but not Cygwin) in
HandleLLVMOptions.cmake, which is where _WIN32 defined too. Just use the
default macro instead of a reinvented one.

See thread "Replacing LLVM_ON_WIN32 with just _WIN32" on llvm-dev and cfe-dev.
No intended behavior change.

This moves over all uses of the macro, but doesn't remove the definition
of it in (llvm-)config.h yet.

llvm-svn: 331127

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Re-land r303274: "[CrashRecovery] Use SEH __try instead of VEH when available"

We have to check gCrashRecoveryEnabled before using __try.

In other words, SEH works too well and we ended up recoveri

Re-land r303274: "[CrashRecovery] Use SEH __try instead of VEH when available"

We have to check gCrashRecoveryEnabled before using __try.

In other words, SEH works too well and we ended up recovering from
crashes in implicit module builds that we weren't supposed to. Only
libclang is supposed to enable CrashRecoveryContext to allow implicit
module builds to crash.

llvm-svn: 303279

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Revert "[CrashRecovery] Use SEH __try instead of VEH when available"

This reverts commit r303274, it appears to break some clang tests.

llvm-svn: 303275

[CrashRecovery] Use SEH __try instead of VEH when available

Summary:
It avoids problems when other libraries raise exceptions. In particular,
OutputDebugString raises an exception that the debugger

[CrashRecovery] Use SEH __try instead of VEH when available

Summary:
It avoids problems when other libraries raise exceptions. In particular,
OutputDebugString raises an exception that the debugger is supposed to
catch and suppress. VEH kicks in first right now, and that is entirely
incorrect.

Unfortunately, GCC does not support SEH, so I've kept the old buggy VEH
codepath around. We could fix it with SetUnhandledExceptionFilter, but
that is not per-thread, so a well-behaved library shouldn't set it.

Reviewers: zturner

Subscribers: llvm-commits, mgorny

Differential Revision: https://reviews.llvm.org/D33261

llvm-svn: 303274

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