[libc++] Remove unused macro in __config

That macro was being defined but not used anywhere in libc++, so it
must be safe to remove it.

As a fly-by fix, also remove mentions of this macro in other

[libc++] Remove unused macro in __config

That macro was being defined but not used anywhere in libc++, so it
must be safe to remove it.

As a fly-by fix, also remove mentions of this macro in other places
in LLVM, to make sure they were not depending on the value defined in
libc++.

Differential Revision: https://reviews.llvm.org/D110289

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Introduce llvm::sys::Process::getProcessId() and adopt it

Differential Revision: https://reviews.llvm.org/D78022

Improve module.pcm lock file performance on machines with high core counts

Summary:
When building a large Xcode project with multiple module dependencies, and mixed Objective-C & Swift, I observed a

Improve module.pcm lock file performance on machines with high core counts

Summary:
When building a large Xcode project with multiple module dependencies, and mixed Objective-C & Swift, I observed a large number of clang processes stalling at zero CPU for 30+ seconds throughout the build. This was especially prevalent on my 18-core iMac Pro.

After some sampling, the major cause appears to be the lock file implementation for precompiled modules in the module cache. When the lock is heavily contended by multiple clang processes, the exponential backoff runs in lockstep, with some of the processes sleeping for 30+ seconds in order to acquire the file lock.

In the attached patch, I implemented a more aggressive polling mechanism that limits the sleep interval to a max of 500ms, and randomizes the wait time. I preserved a limited form of exponential backoff. I also updated the code to use cross-platform timing, thread sleep, and random number capabilities available in C++11.

On iMac Pro (2.3 GHz Intel Xeon W, 18 core):

Xcode 11.1 bundled clang:

502.2 seconds (average of 5 runs)

Custom clang build with LockFileManager patch applied:

276.6 seconds (average of 5 runs)

This is a 1.82x speedup for this use case.

On MacBook Pro (4 core 3.1GHz Intel i7):

Xcode 11.1 bundled clang:

539.4 seconds (average of 2 runs)

Custom clang build with LockFileManager patch applied:

509.5 seconds (average of 2 runs)

As expected, machines with fewer cores benefit less from this change.

```
Call graph:
2992 Thread_393602 DispatchQueue_1: com.apple.main-thread (serial)
2992 start (in libdyld.dylib) + 1 [0x7fff6a1683d5]
2992 main (in clang) + 297 [0x1097a1059]
2992 driver_main(int, char const**) (in clang) + 2803 [0x1097a5513]
2992 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (in clang) + 1608 [0x1097a7cc8]
2992 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (in clang) + 3299 [0x1097dace3]
2992 clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (in clang) + 509 [0x1097dcc1d]
2992 clang::FrontendAction::Execute() (in clang) + 42 [0x109818b3a]
2992 clang::ParseAST(clang::Sema&, bool, bool) (in clang) + 185 [0x10981b369]
2992 clang::Parser::ParseFirstTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&) (in clang) + 37 [0x10983e9b5]
2992 clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&) (in clang) + 141 [0x10983ecfd]
2992 clang::Parser::ParseExternalDeclaration(clang::Parser::ParsedAttributesWithRange&, clang::ParsingDeclSpec*) (in clang) + 695 [0x10983f3b7]
2992 clang::Parser::ParseObjCAtDirectives(clang::Parser::ParsedAttributesWithRange&) (in clang) + 637 [0x10a9be9bd]
2992 clang::Parser::ParseModuleImport(clang::SourceLocation) (in clang) + 170 [0x10c4841ba]
2992 clang::Parser::ParseModuleName(clang::SourceLocation, llvm::SmallVectorImpl<std::__1::pair<clang::IdentifierInfo*, clang::SourceLocation> >&, bool) (in clang) + 503 [0x10c485267]
2992 clang::Preprocessor::Lex(clang::Token&) (in clang) + 316 [0x1098285cc]
2992 clang::Preprocessor::LexAfterModuleImport(clang::Token&) (in clang) + 690 [0x10cc7af62]
2992 clang::CompilerInstance::loadModule(clang::SourceLocation, llvm::ArrayRef<std::__1::pair<clang::IdentifierInfo*, clang::SourceLocation> >, clang::Module::NameVisibilityKind, bool) (in clang) + 7989 [0x10bba6535]
2992 compileAndLoadModule(clang::CompilerInstance&, clang::SourceLocation, clang::SourceLocation, clang::Module*, llvm::StringRef) (in clang) + 296 [0x10bba8318]
2992 llvm::LockFileManager::waitForUnlock() (in clang) + 91 [0x10b6953ab]
2992 nanosleep (in libsystem_c.dylib) + 199 [0x7fff6a22c914]
2992 __semwait_signal (in libsystem_kernel.dylib) + 10 [0x7fff6a2a0f32]

```

Differential Revision: https://reviews.llvm.org/D69575

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Make llvm::StringRef to std::string conversions explicit.

This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.

This is mostly m

Make llvm::StringRef to std::string conversions explicit.

This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.

This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.

This doesn't actually modify StringRef yet, I'll do that in a follow-up.

show more ...

[LockFileManager] Make default waitForUnlock timeout a parameter, NFC

Patch by Xi Ge!

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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[Support] Fix some Wundef warnings

For the _WIN32 macro, it is the definedness that matters rather than
the value. Most uses of the macro already rely on the definedness.
This commit fixes the few

[Support] Fix some Wundef warnings

For the _WIN32 macro, it is the definedness that matters rather than
the value. Most uses of the macro already rely on the definedness.
This commit fixes the few remaining uses that relied on the value.

Differential Revision: https://reviews.llvm.org/D51105

llvm-svn: 340520

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LTO: Keep file handles open for memory mapped files.

On Windows we've observed that if you open a file, write to it, map it into
memory and close the file handle, the contents of the memory mapping

LTO: Keep file handles open for memory mapped files.

On Windows we've observed that if you open a file, write to it, map it into
memory and close the file handle, the contents of the memory mapping can
sometimes be incorrect. That was what we did when adding an entry to the
ThinLTO cache using the TempFile and MemoryBuffer classes, and it was causing
intermittent build failures on Chromium's ThinLTO bots on Windows. More
details are in the associated Chromium bug (crbug.com/786127).

We can prevent this from happening by keeping a handle to the file open while
the mapping is active. So this patch changes the mapped_file_region class to
duplicate the file handle when mapping the file and close it upon unmapping it.

One gotcha is that the file handle that we keep open must not have been
created with FILE_FLAG_DELETE_ON_CLOSE, as otherwise the operating system
will prevent other processes from opening the file. We can achieve this
by avoiding the use of FILE_FLAG_DELETE_ON_CLOSE altogether. Instead,
we use SetFileInformationByHandle with FileDispositionInfo to manage the
delete-on-close bit. This lets us remove the hack that we used to use to
clear the delete-on-close bit on a file opened with FILE_FLAG_DELETE_ON_CLOSE.

A downside of using SetFileInformationByHandle/FileDispositionInfo as
opposed to FILE_FLAG_DELETE_ON_CLOSE is that it prevents us from using
CreateFile to open the file while the flag is set, even within the same
process. This doesn't seem to matter for almost every client of TempFile,
except for LockFileManager, which calls sys::fs::create_link to create a
hard link from the lock file, and in the process of doing so tries to open
the file. To prevent this change from breaking LockFileManager I changed it
to stop using TempFile by effectively reverting r318550.

Differential Revision: https://reviews.llvm.org/D48051

llvm-svn: 334630

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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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[Support] Replace hand-written scope_exit with make_scope_exit.

No functionality change intended.

llvm-svn: 325460

Use TempFile in the implementation of LockFileManager.

This move some of the complexity over to the lower level TempFile.

It also makes it a bit more explicit where errors are ignored since we
now

Use TempFile in the implementation of LockFileManager.

This move some of the complexity over to the lower level TempFile.

It also makes it a bit more explicit where errors are ignored since we
now have a call to consumeError.

llvm-svn: 318550

show more ...

Simplify and rename variable.

std::error_code can represent success, so we don't need a
Optional<std::error_code>.

Rename the variable to avoid confusion with the type Error.

llvm-svn: 318111

Simplify. NFC.

llvm-svn: 318104

[raw_fd_ostream] report actual error in error messages

Summary:
Previously, we would emit error messages like "IO failure on output
stream". This change causes use to include information about what

[raw_fd_ostream] report actual error in error messages

Summary:
Previously, we would emit error messages like "IO failure on output
stream". This change causes use to include information about what
actually went wrong, e.g. "No space left on device".

Reviewers: sunfish, rnk

Reviewed By: rnk

Subscribers: mehdi_amini, llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D39203

llvm-svn: 316404

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Sort the remaining #include lines in include/... and lib/....

I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line

Sort the remaining #include lines in include/... and lib/....

I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line with a #include and let it re-sort things according to the precise
LLVM rules for include ordering baked into clang-format these days.

I've reverted a number of files where the results of sorting includes
isn't healthy. Either places where we have legacy code relying on
particular include ordering (where possible, I'll fix these separately)
or where we have particular formatting around #include lines that
I didn't want to disturb in this patch.

This patch is *entirely* mechanical. If you get merge conflicts or
anything, just ignore the changes in this patch and run clang-format
over your #include lines in the files.

Sorry for any noise here, but it is important to keep these things
stable. I was seeing an increasing number of patches with irrelevant
re-ordering of #include lines because clang-format was used. This patch
at least isolates that churn, makes it easy to skip when resolving
conflicts, and gets us to a clean baseline (again).

llvm-svn: 304787

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[LockFileManager] Reduce lock timeout

Go back to behavior pre-r231309 and reduce the timeout from 8 to ~1.5
min now that we have (a) PCMCache mechanism (r298165) and (b) timeout
that doesn't cause a

[LockFileManager] Reduce lock timeout

Go back to behavior pre-r231309 and reduce the timeout from 8 to ~1.5
min now that we have (a) PCMCache mechanism (r298165) and (b) timeout
that doesn't cause a failure, but actually build the module (r298175).

rdar://problem/30297862

llvm-svn: 298176

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Missing includes.

llvm-svn: 281450

Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes.

Differential revision: https://reviews.llvm.org/D23789

llvm-svn: 279535

[LockFileManager] Improve error output by using better error messages

This is currently used by clang to lock access to modules; improve the
error message so that clang can use better output message

[LockFileManager] Improve error output by using better error messages

This is currently used by clang to lock access to modules; improve the
error message so that clang can use better output messages from locking
error issues.

rdar://problem/26529101

Differential Review: http://reviews.llvm.org/D20942

llvm-svn: 271755

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Reapply "Use gethostuuid() on Mac to identify hosts for LockFileManager"

Reapplies r241005 after fixing the build on non-Mac platforms. Original
commit message below.

The hostname can be very unsta

Reapply "Use gethostuuid() on Mac to identify hosts for LockFileManager"

Reapplies r241005 after fixing the build on non-Mac platforms. Original
commit message below.

The hostname can be very unstable when there are many machines on the
network competing for the same name. Using the hardware UUID makes it
less likely to have collisions or to consider files written by the
current host to be owned by a different one at a later time.

rdar://problem/21512307

llvm-svn: 241012

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Revert "Use gethostuuid() on Mac to identify hosts for LockFileManager"

Broke non-Mac builds.

This reverts commit r241005.

llvm-svn: 241007

Use gethostuuid() on Mac to identify hosts for LockFileManager

The hostname can be very unstable when there are many machines on the
network competing for the same name. Using the hardware UUID make

Use gethostuuid() on Mac to identify hosts for LockFileManager

The hostname can be very unstable when there are many machines on the
network competing for the same name. Using the hardware UUID makes it
less likely to have collisions or to consider files written by the
current host to be owned by a different one at a later time.

rdar://problem/21512307

llvm-svn: 241005

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Clean up unique lock files on signal and always release the lock

Make sure to remove the unique lock file, which is what the .lock
symlink points to, if there is a signal while the lock is held. Thi

Clean up unique lock files on signal and always release the lock

Make sure to remove the unique lock file, which is what the .lock
symlink points to, if there is a signal while the lock is held. This
will release the lock, since the symlink will point to nothing (already
tested in unit tests). For good measure, also clean up the unique lock
file if there is an error or signal before the lock is acquired.

I will add a clang test.

rdar://problem/21512307

llvm-svn: 240967

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