Commit Graph

550 Commits

Author SHA1 Message Date
Lang Hames 93d2bdda6b [Support] Renamed member 'Size' to 'AllocatedSize' in MemoryBlock and OwningMemoryBlock.
Rename member 'Size' to 'AllocatedSize' in order to provide a hint that the
allocated size may be different than the requested size. Comments are added to
clarify this point.  Updated the InMemoryBuffer in FileOutputBuffer.cpp to track
the requested buffer size.

Patch by Machiel van Hooren. Thanks Machiel!

https://reviews.llvm.org/D61599

llvm-svn: 361195
2019-05-20 20:53:05 +00:00
Lang Hames e4b4ab6d26 [Support] Add error handling to sys::Process::getPageSize().
This patch changes the return type of sys::Process::getPageSize to
Expected<unsigned> to account for the fact that the underlying syscalls used to
obtain the page size may fail (see below).

For clients who use the page size as an optimization only this patch adds a new
method, getPageSizeEstimate, which calls through to getPageSize but discards
any error returned and substitues a "reasonable" page size estimate estimate
instead. All existing LLVM clients are updated to call getPageSizeEstimate
rather than getPageSize.

On Unix, sys::Process::getPageSize is implemented in terms of getpagesize or
sysconf, depending on which macros are set. The sysconf call is documented to
return -1 on failure. On Darwin getpagesize is implemented in terms of sysconf
and may also fail (though the manpage documentation does not mention this).
These failures have been observed in practice when highly restrictive sandbox
permissions have been applied. Without this patch, the result is that
getPageSize returns -1, which wreaks havoc on any subsequent code that was
assuming a sane page size value.

<rdar://problem/41654857>

Reviewers: dblaikie, echristo

Subscribers: kristina, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59107

llvm-svn: 360221
2019-05-08 02:11:07 +00:00
Kadir Cetinkaya 8fdc5abffe [llvm][Support] Provide interface to set thread priorities
Summary:
We have a multi-platform thread priority setting function(last piece
landed with D58683), I wanted to make this available to all llvm community,
there seem to be other users of such functionality with portability fixmes:
lib/Support/CrashRecoveryContext.cpp
tools/clang/tools/libclang/CIndex.cpp

Reviewers: gribozavr, ioeric

Subscribers: krytarowski, jfb, kristina, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59130

llvm-svn: 358494
2019-04-16 14:32:43 +00:00
Andrew Ng 2fc69abf5b [Support] MemoryBlock size should reflect the requested size
This patch mirrors the change made to the Unix equivalent in
r351916. This in turn fixes bugs related to the use of FileOutputBuffer
to output to "-", i.e. stdout, on Windows.

Differential Revision: https://reviews.llvm.org/D59663

llvm-svn: 357058
2019-03-27 10:26:21 +00:00
Alexandre Ganea 14d58f5986 Fix SupportTests.exe/AllocationTests/MappedMemoryTest.AllocAndReleaseHuge when the machine doesn't have large pages enabled.
llvm-svn: 355067
2019-02-28 03:42:07 +00:00
Alexandre Ganea b05ba93578 [Memory] Add basic support for large/huge memory pages
This patch introduces Memory::MF_HUGE_HINT which indicates that allocateMappedMemory() shall return a pointer to a large memory page.
However the flag is a hint because we're not guaranteed in any way that we will get back a large memory page. There are several restrictions:

- Large/huge memory pages aren't enabled by default on modern OSes (Windows 10 and Linux at least), and should be manually enabled/reserved.
- Once enabled, it should be kept in mind that large pages are physical only, they can't be swapped.
- Memory fragmentation can affect the availability of large pages, especially after running the OS for a long time and/or running along many other applications.

Memory::allocateMappedMemory() will fallback to 4KB pages if it can't allocate 2MB large pages (if Memory::MF_HUGE_HINT is provided)

Currently, Memory::MF_HUGE_HINT only works on Windows. The hint will be ignored on Linux, 4KB pages will always be returned.

Differential Revision: https://reviews.llvm.org/D58718

llvm-svn: 355065
2019-02-28 02:47:34 +00:00
Chandler Carruth 2946cd7010 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
2019-01-19 08:50:56 +00:00
Zachary Turner 4e83923d83 Don't write #include "Windows/WindowsSupport.h" from the Windows dir.
This generates -Wnonportable-include-dir warnings, and doesn't need
to be there.  It seems this was just checked in on accident.

llvm-svn: 350655
2019-01-08 21:05:34 +00:00
Shoaib Meenai 96929fdd42 [Support] Fix FileNameLength passed to SetFileInformationByHandle
The rename_internal function used for Windows has a minor bug where the
filename length is passed as a character count instead of a byte count.
Windows internally ignores this field, but other tools that hook NT
api's may use the documented behavior:

MSDN documentation specifying the size should be in bytes:
https://docs.microsoft.com/en-us/windows/desktop/api/winbase/ns-winbase-_file_rename_info

Patch by Ben Hillis.

Differential Revision: https://reviews.llvm.org/D55624

llvm-svn: 348995
2018-12-13 00:08:25 +00:00
Jonas Devlieghere b23f430ec9 [FileSystem] Add expand_tilde function
In D54435 there was some discussion about the expand_tilde flag for
real_path that I wanted to expose through the VFS. The consensus is that
these two things should be separate functions. Since we already have the
code for this I went ahead and added a function expand_tilde that does
just that.

Differential revision: https://reviews.llvm.org/D54448

llvm-svn: 346776
2018-11-13 18:23:32 +00:00
Reid Kleckner c30932248f [Windows] Simplify WindowsSupport.h
Sink Windows version detection code from WindowsSupport.h to Path.inc.
These functions don't need to be inlined. I randomly picked Process.inc
for the Windows version helpers, since that's the most related file.

Sink MakeErrMsg to Program.inc since it's the main client.

Move those functions into the llvm namespace, and delete the scoped
handle copy and assignment operators.

Reviewers: zturner, aganea

Differential Revision: https://reviews.llvm.org/D54182

llvm-svn: 346280
2018-11-06 23:39:59 +00:00
Reid Kleckner 0d56edb9ab Silence deprecation warning for GetVersionEx with clang-cl
llvm-svn: 346268
2018-11-06 21:40:32 +00:00
Martin Storsjo c6fcdd3b30 [Support] Fix `warning: unknown pragma ignored` for mingw target
Differential Revision: https://reviews.llvm.org/D54133

llvm-svn: 346218
2018-11-06 09:08:20 +00:00
Alexandre Ganea 3b9b4d2156 Only call FlushFileBuffers() when writing executables on Windows
This is a follow-up for "r325274: Call FlushFileBuffers on output files."

Previously, FlushFileBuffers() was called in all cases when writing a file. The objective was to go around a bug in the Windows kernel (as described here: https://randomascii.wordpress.com/2018/02/25/compiler-bug-linker-bug-windows-kernel-bug/). However that is required only when writing EXEs, any other file type doesn't need flushing.

This patch calls FlushFileBuffers() only for EXEs. In addition, we completly disable FlushFileBuffers() for known Windows 10 versions that do not exhibit the original kernel bug.

Differential Revision: https://reviews.llvm.org/D53727

llvm-svn: 346152
2018-11-05 19:14:10 +00:00
Nico Weber d4ed32c526 Remove dead function user_cache_directory()
It's been unused since it was added almost 3 years ago in
https://reviews.llvm.org/D13801

Motivated by https://reviews.llvm.org/rL342002 since it removes one of the
functions keeping a ref to SHGetKnownFolderPath.

Differential Revision: https://reviews.llvm.org/D52184

llvm-svn: 342485
2018-09-18 15:06:16 +00:00
Kristina Brooks 3a55d1ef27 [Support] sys::fs::directory_entry includes the file_type.
This is available on most platforms (Linux/Mac/Win/BSD) with no extra syscalls.
On other platforms (e.g. Solaris) we stat() if this information is requested.

This will allow switching clang's VFS to efficiently expose (path, type) when
traversing a directory. Currently it exposes an entire Status, but does so by
calling fs::status() on all platforms.
Almost all callers only need the path, and all callers only need (path, type).

Patch by sammccall (Sam McCall)

Differential Revision: https://reviews.llvm.org/D51918

llvm-svn: 342089
2018-09-12 22:08:10 +00:00
Reid Kleckner 45265d996b [Support] Quote arguments containing \n on Windows
Fixes at_file.c test failure caused by r341988. We may want to change
how we treat \n in our tokenizer, but this is probably a good fix
regardless, since we can invoke all kinds of programs with different
interpretations of the command line quoting rules.

llvm-svn: 341992
2018-09-11 21:02:03 +00:00
Reid Kleckner f6968d886a [Support] Avoid calling CommandLineToArgvW from shell32.dll
Summary:
Shell32.dll depends on gdi32.dll and user32.dll, which are mostly DLLs
for Windows GUI functionality. LLVM's utilities don't typically need GUI
functionality, and loading these DLLs seems to be slowing down startup.
Also, we already have an implementation of Windows command line
tokenization in cl::TokenizeWindowsCommandLine, so we can just use it.

The goal is to get the original argv in UTF-8, so that it can pass
through most LLVM string APIs. A Windows process starts life with a
UTF-16 string for its command line, and it can be retreived with
GetCommandLineW from kernel32.dll.

Previously, we would:
1. Get the wide command line
2. Call CommandLineToArgvW to handle quoting rules and separate it into
   arguments.
3. For each wide argument, expand wildcards (* and ?) using
   FindFirstFileW.
4. Convert each argument to UTF-8

Now we:
1. Get the wide command line, convert the whole thing to UTF-8
2. Tokenize the UTF-8 command line with cl::TokenizeWindowsCommandLine
3. For each argument, expand wildcards if present
   - This requires converting back to UTF-16 to call FindFirstFileW
   - Results of FindFirstFileW must be converted back to UTF-8

Reviewers: zturner

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D51941

llvm-svn: 341988
2018-09-11 20:22:39 +00:00
David Bolvansky ecf0c55b63 Set console mode when -fansi-escape-codes is enabled
Summary:
Windows console now supports supports ANSI escape codes, but we need to enable it using SetConsoleMode with ENABLE_VIRTUAL_TERMINAL_PROCESSING flag.

Fixes https://bugs.llvm.org/show_bug.cgi?id=38817


Tested on Windows 10, screenshot:
https://i.imgur.com/bqYq0Uy.png

Reviewers: zturner, chandlerc

Reviewed By: zturner

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D51611

llvm-svn: 341396
2018-09-04 19:23:05 +00:00
Jordan Rupprecht 97ea485041 [Support] NFC: Allow modifying access/modification times independently in sys::fs::setLastModificationAndAccessTime.
Summary:
Add an overload to sys::fs::setLastModificationAndAccessTime that allows setting last access and modification times separately. This will allow tools to use this API when they want to preserve both the access and modification times from an input file, which may be different.

Also note that both the POSIX (futimens/futimes) and Windows (SetFileTime) APIs take the two timestamps in the order of (1) access (2) modification time, so this renames the method to "setLastAccessAndModificationTime" to make it clear which timestamp is which.

For existing callers, the 1-arg overload just sets both timestamps to the same thing.

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D50521

llvm-svn: 339628
2018-08-13 23:03:45 +00:00
Jeremy Morse 019406554b [Windows FS] Allow moving files in TempFile::keep
In r338216 / D49860 TempFile::keep was extended to allow keeping across
filesystems. The aim on Windows was to have this happen in rename_internal
using the existing system API. However, to fix an issue and preserve the
idea of "renaming" not being a move, put Windows keep-across-filesystem in
TempFile::keep.

Differential Revision: https://reviews.llvm.org/D50048

llvm-svn: 338841
2018-08-03 10:13:35 +00:00
Jonas Devlieghere ae1727e3dd [dsymutil] Simplify temporary file handling.
Dsymutil's update functionality was broken on Windows because we tried
to rename a file while we're holding open handles to that file. TempFile
provides a solution for this through its keep(Twine) method. This patch
changes dsymutil to make use of that functionality.

Differential revision: https://reviews.llvm.org/D49860

llvm-svn: 338216
2018-07-29 14:56:15 +00:00
Andrew Ng 089303d8ff [ThinLTO] Update ThinLTO cache file atimes when on Windows
ThinLTO cache file access times are used for expiration based pruning
and since Vista, file access times are not updated by Windows by
default:

https://blogs.technet.microsoft.com/filecab/2006/11/07/disabling-last-access-time-in-windows-vista-to-improve-ntfs-performance

This means on Windows, cache files are currently being pruned from
creation time. This change manually updates cache files that are
accessed by ThinLTO, when on Windows.

Patch by Owen Reynolds.

Differential Revision: https://reviews.llvm.org/D47266

llvm-svn: 336276
2018-07-04 14:17:10 +00:00
Peter Collingbourne 881ba10465 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
2018-06-13 18:03:14 +00:00
Hans Wennborg 12ba9ec929 Do not enforce absolute path argv0 in windows
Even if we support no-canonical-prefix on
clang-cl(https://reviews.llvm.org/D47480), argv0 becomes absolute path
in clang-cl and that embeds absolute path in /showIncludes.

This patch removes such full path normalization from InitLLVM on
windows, and that removes absolute path from clang-cl output
(obj/stdout/stderr) when debug flag is disabled.

Patch by Takuto Ikuta!

Differential Revision https://reviews.llvm.org/D47578

llvm-svn: 334602
2018-06-13 14:29:26 +00:00
Zachary Turner 08426e1f9f Refactor ExecuteAndWait to take StringRefs.
This simplifies some code which had StringRefs to begin with, and
makes other code more complicated which had const char* to begin
with.

In the end, I think this makes for a more idiomatic and platform
agnostic API.  Not all platforms launch process with null terminated
c-string arrays for the environment pointer and argv, but the api
was designed that way because it allowed easy pass-through for
posix-based platforms.  There's a little additional overhead now
since on posix based platforms we'll be takign StringRefs which
were constructed from null terminated strings and then copying
them to null terminate them again, but from a readability and
usability standpoint of the API user, I think this API signature
is strictly better.

llvm-svn: 334518
2018-06-12 17:43:52 +00:00
Zachary Turner 15243d5a6d Attempt 3: Resubmit "[Support] Expose flattenWindowsCommandLine."
I took some liberties and quoted fewer characters than before,
based on an article from MSDN which says that only certain characters
cause an arg to require quoting.  This seems to be incorrect, though,
and worse it seems to be a difference in Windows version.  The bot
that fails is Windows 7, and I can't reproduce the failure on Win
10.  But it's definitely related to quoting and special characters,
because both tests that fail have a * in the argument, which is one
of the special characters that would cause an argument to be quoted
before but not any longer after the new patch.

Since I don't have Win 7, all I can do is just guess that I need to
restore the old quoting rules.  So this patch does that in hopes that
it fixes the problem on Windows 7.

llvm-svn: 334375
2018-06-10 20:57:14 +00:00
Zachary Turner 071a09053a Revert "Resubmit "[Support] Expose flattenWindowsCommandLine.""
This reverts commit 65243b6d19143cb7a03f68df0169dcb63e8b4632.

Seems like it's not a flake.  It might have something to do with
the '*' character being in a command line.

llvm-svn: 334356
2018-06-10 03:16:25 +00:00
Zachary Turner 5e119768a1 Resubmit "[Support] Expose flattenWindowsCommandLine."
There were a few linux compilation failures, but other than that
I think this was just a flake that caused the tests to fail.  I'm
going to resubmit and see if the failures go away, if not I'll
revert again.

llvm-svn: 334355
2018-06-10 02:46:11 +00:00
Zachary Turner 1fbca91c07 Revert "[Support] Expose flattenWindowsCommandLine."
This reverts commit 10d2e88e87150a35dc367ba30716189d2af26774.

This is causing some test failures for some reason, reverting
while I investigate.

llvm-svn: 334354
2018-06-09 23:07:39 +00:00
Zachary Turner 48c3341cfe [Support] Expose flattenWindowsCommandLine.
This function was internal to Program.inc, but I've needed this
on several occasions when I've had to use CreateProcess without
llvm's sys::Execute functions.  In doing so, I noticed that the
function was written using unsafe C-string access and was pretty
hard to understand / make sense of, so I've also re-written the
functions to use more modern LLVM constructs.

llvm-svn: 334353
2018-06-09 22:44:44 +00:00
Zachary Turner 66ef5d3cd6 Clean up some code in Program.
NFC here, this just raises some platform specific ifdef hackery
out of a class and creates proper platform-independent typedefs
for the relevant things.  This allows these typedefs to be
reused in other places without having to reinvent this preprocessor
logic.

llvm-svn: 334294
2018-06-08 15:16:25 +00:00
Zachary Turner 6edfecb883 Add a file open flag that disables O_CLOEXEC.
O_CLOEXEC is the right default, but occasionally you don't
want this.  This is especially true for tools like debuggers
where you might need to spawn the child process with specific
files already open, but it's occasionally useful in other
scenarios as well, like when you want to do some IPC between
parent and child.

llvm-svn: 334293
2018-06-08 15:15:56 +00:00
Zachary Turner 9d2cfa6ccc Expose a single global file open function.
This one allows much more flexibility than the standard
openFileForRead / openFileForWrite functions.  Since there is now
just one "real" function that does the work, all other implementations
simply delegate to this one.

llvm-svn: 334246
2018-06-07 23:25:13 +00:00
Zachary Turner 1f67a3cba9 [FileSystem] Split up the OpenFlags enumeration.
This breaks the OpenFlags enumeration into two separate
enumerations: OpenFlags and CreationDisposition.  The first
controls the behavior of the API depending on whether or not
the target file already exists, and is not a flags-based
enum.  The second controls more flags-like values.

This yields a more easy to understand API, while also allowing
flags to be passed to the openForRead api, where most of the
values didn't make sense before.  This also makes the apis more
testable as it becomes easy to enumerate all the configurations
which make sense, so I've added many new tests to exercise all
the different values.

llvm-svn: 334221
2018-06-07 19:58:58 +00:00
Zachary Turner 63db25ba0d [Support] Add functions that operate on native file handles on Windows.
Windows' CRT has a limit of 512 open file descriptors, and fds which are
generated by converting a HANDLE via _get_osfhandle count towards this
limit as well.

Regardless, often you find yourself marshalling back and forth between
native HANDLE objects and fds anyway. If we know from the getgo that
we're going to need to work directly with the handle, we can cut out the
marshalling layer while also not contributing to filling up the CRT's
very limited handle table.

On Unix these functions just delegate directly to the existing set of
functions since an fd *is* the native file type. It would be nice, very
long term, if we could convert most uses of fds to file_t.

Differential Revision: https://reviews.llvm.org/D47688

llvm-svn: 333945
2018-06-04 19:38:11 +00:00
Zachary Turner b44d7a0da1 Move some function declarations out of WindowsSupport.h
The idea behind WindowsSupport.h is that it's in the source directory so
that windows.h'isms don't leak out into the larger LLVM project. To that
end, any symbol that references a symbol from windows.h must be in this
private header, and not in a public header.

However, we had some useful utility functions in WindowsSupport.h which
have no dependency on the Windows API, but still only make sense on
Windows. Those functions should be usable outside of Support since there
is no risk of causing a windows.h leak. Although this introduces some
preprocessor logic in some header files, It's not too egregious and it's
better than the alternative of duplicating a ton of code.

Differential Revision: https://reviews.llvm.org/D47662

llvm-svn: 333798
2018-06-01 22:23:46 +00:00
Petr Hosek f92ca01e42 [Support] Avoid normalization in sys::getDefaultTargetTriple
The return value of sys::getDefaultTargetTriple, which is derived from
-DLLVM_DEFAULT_TRIPLE, is used to construct tool names, default target,
and in the future also to control the search path directly; as such it
should be used textually, without interpretation by LLVM.

Normalization of this value may lead to unexpected results, for example
if we configure LLVM with -DLLVM_DEFAULT_TARGET_TRIPLE=x86_64-linux-gnu,
normalization will transform that value to x86_64--linux-gnu. Driver will
use that value to search for tools prefixed with x86_64--linux-gnu- which
may be confusing. This is also inconsistent with the behavior of the
--target flag which is taken as-is without any normalization and overrides
the value of LLVM_DEFAULT_TARGET_TRIPLE.

Users of sys::getDefaultTargetTriple already perform their own
normalization as needed, so this change shouldn't impact existing logic.

Differential Revision: https://reviews.llvm.org/D47153

llvm-svn: 333307
2018-05-25 20:39:37 +00:00
Nico Weber 41597b92b1 Revert 332750, llvm part (see comment on D46910).
llvm-svn: 332823
2018-05-20 23:03:17 +00:00
Petr Hosek 24b61ac832 [Support] Avoid normalization in sys::getDefaultTargetTriple
The return value of sys::getDefaultTargetTriple, which is derived from
-DLLVM_DEFAULT_TRIPLE, is used to construct tool names, default target,
and in the future also to control the search path directly; as such it
should be used textually, without interpretation by LLVM.

Normalization of this value may lead to unexpected results, for example
if we configure LLVM with -DLLVM_DEFAULT_TARGET_TRIPLE=x86_64-linux-gnu,
normalization will transform that value to x86_64--linux-gnu. Driver will
use that value to search for tools prefixed with x86_64--linux-gnu- which
may be confusing. This is also inconsistent with the behavior of the
--target flag which is taken as-is without any normalization and overrides
the value of LLVM_DEFAULT_TARGET_TRIPLE.

Users of sys::getDefaultTargetTriple already perform their own
normalization as needed, so this change shouldn't impact existing logic.

Differential Revision: https://reviews.llvm.org/D46910

llvm-svn: 332750
2018-05-18 18:33:07 +00:00
JF Bastien aa1333a91f Signal handling should be signal-safe
Summary:
Before this patch, signal handling wasn't signal safe. This leads to real-world
crashes. It used ManagedStatic inside of signals, this can allocate and can lead
to unexpected state when a signal occurs during llvm_shutdown (because
llvm_shutdown destroys the ManagedStatic). It also used cl::opt without custom
backing storage. Some de-allocation was performed as well. Acquiring a lock in a
signal handler is also a great way to deadlock.

We can't just disable signals on llvm_shutdown because the signals might do
useful work during that shutdown. We also can't just disable llvm_shutdown for
programs (instead of library uses of clang) because we'd have to then mark the
pointers as not leaked and make sure all the ManagedStatic uses are OK to leak
and remain so.

Move all of the code to lock-free datastructures instead, and avoid having any
of them in an inconsistent state. I'm not trying to be fancy, I'm not using any
explicit memory order because this code isn't hot. The only purpose of the
atomics is to guarantee that a signal firing on the same or a different thread
doesn't see an inconsistent state and crash. In some cases we might miss some
state (for example, we might fail to delete a temporary file), but that's fine.

Note that I haven't touched any of the backtrace support despite it not
technically being totally signal-safe. When that code is called we know
something bad is up and we don't expect to continue execution, so calling
something that e.g. sets errno is the least of our problems.

A similar patch should be applied to lib/Support/Windows/Signals.inc, but that
can be done separately.

Fix r332428 which I reverted in r332429. I originally used double-wide CAS
because I was lazy, but some platforms use a runtime function for that which
thankfully failed to link (it would have been bad for signal handlers
otherwise). I use a separate flag to guard the data instead.

<rdar://problem/28010281>

Reviewers: dexonsmith

Subscribers: steven_wu, llvm-commits
llvm-svn: 332496
2018-05-16 17:25:35 +00:00
JF Bastien b8931c1cf4 Revert "Signal handling should be signal-safe"
Some bots don't have double-pointer width compare-and-exchange. Revert for now.q

llvm-svn: 332429
2018-05-16 04:36:37 +00:00
JF Bastien 253aa8b099 Signal handling should be signal-safe
Summary:
Before this patch, signal handling wasn't signal safe. This leads to real-world
crashes. It used ManagedStatic inside of signals, this can allocate and can lead
to unexpected state when a signal occurs during llvm_shutdown (because
llvm_shutdown destroys the ManagedStatic). It also used cl::opt without custom
backing storage. Some de-allocation was performed as well. Acquiring a lock in a
signal handler is also a great way to deadlock.

We can't just disable signals on llvm_shutdown because the signals might do
useful work during that shutdown. We also can't just disable llvm_shutdown for
programs (instead of library uses of clang) because we'd have to then mark the
pointers as not leaked and make sure all the ManagedStatic uses are OK to leak
and remain so.

Move all of the code to lock-free datastructures instead, and avoid having any
of them in an inconsistent state. I'm not trying to be fancy, I'm not using any
explicit memory order because this code isn't hot. The only purpose of the
atomics is to guarantee that a signal firing on the same or a different thread
doesn't see an inconsistent state and crash. In some cases we might miss some
state (for example, we might fail to delete a temporary file), but that's fine.

Note that I haven't touched any of the backtrace support despite it not
technically being totally signal-safe. When that code is called we know
something bad is up and we don't expect to continue execution, so calling
something that e.g. sets errno is the least of our problems.

A similar patch should be applied to lib/Support/Windows/Signals.inc, but that
can be done separately.

<rdar://problem/28010281>

Reviewers: dexonsmith

Subscribers: aheejin, llvm-commits

Differential Revision: https://reviews.llvm.org/D46858

llvm-svn: 332428
2018-05-16 04:30:00 +00:00
JF Bastien 93bce5108b [NFC] Update comments
Don't prepend function or data name before each comment. Split into its own NFC patch as requested in D46858.

llvm-svn: 332323
2018-05-15 04:06:28 +00:00
Brian Gesiak 82de4e6b93 [Support] Add docs for 'openFileFor{Write,Read}'
Summary:
Add documentation for the LLVM Support functions `openFileForWrite` and
`openFileForRead`. The `openFileForRead` parameter `RealPath`, in
particular, I think warranted some explanation.

In addition, make the behavior of the functions more consistent across
platforms. Prior to this patch, Windows would set or not set the result
file descriptor based on the nature of the error, whereas Unix would
consistently set it to `-1` if the open failed. Make Windows
consistently set it to `-1` as well.

Test Plan:
1. `ninja check-llvm`
2. `ninja docs-llvm-html`

Reviewers: zturner, rnk, danielmartin, scanon

Reviewed By: danielmartin, scanon

Subscribers: scanon, danielmartin, llvm-commits

Differential Revision: https://reviews.llvm.org/D46499

llvm-svn: 332075
2018-05-11 01:47:27 +00:00
Adrian Prantl 5f8f34e459 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
2018-05-01 15:54:18 +00:00
Aaron Smith 02caafd7e5 [support] Revert the changes made to Path.inc for the default Windows code page
Path.inc/widenPath tries to decode the path using both UTF-8 and the default Windows code page.
This is no longer necessary with the new InitLLVM method which ensures that the command line
arguemnts are already UTF-8 on Windows.
 

llvm-svn: 330266
2018-04-18 15:26:26 +00:00
Rui Ueyama e6ac9f5ec3 Rename sys::Process::GetArgumentVector -> sys::windows::GetCommandLineArguments
GetArgumentVector (or GetCommandLineArguments) is very Windows-specific.
I think it doesn't make much sense to provide that function from sys::Process.

I also made a change so that the function takes a BumpPtrAllocator
instead of a SpecificBumpPtrAllocator. The latter is the class to call
dtors, but since char * is trivially destructible, we should use the
former class.

Differential Revision: https://reviews.llvm.org/D45641

llvm-svn: 330216
2018-04-17 21:09:16 +00:00
Martin Storsjo 8293161712 [Support] Fix building for Windows on ARM
The commit in SVN r310001 that added support for this actually didn't
use the right struct field for the frame pointer - for ARM, there is
no register named Fp in the CONTEXT struct. On Windows, the R11
register is used as frame pointer.

Differential Revision: https://reviews.llvm.org/D45590

llvm-svn: 329991
2018-04-13 06:38:02 +00:00
Aaron Smith 8a5ea61886 Windows needs the current codepage instead of utf8 sometimes
Llvm-mc (and tools that use Path.inc on Windows) assume that strings are utf-8 
encoded, however, this is not always the case. On Windows the default codepage 
is not utf-8, so most of the time the strings are not utf-8 encoded.

The lld test 'format-binary-non-ascii' uses llvm-mc with a file with non-ascii 
characters in the name which is how this bug was found. The test fails when run 
using Python 3 because it uses properly encoded unicode strings (Python 2 actually 
ends up using a byte string which is not utf-8 encoded, so the test passes, but 
that's separate issue). 

Patch by Stella Stamenova!

llvm-svn: 329468
2018-04-07 00:32:59 +00:00