Allow clients of the llvm library to opt-in to one-shot SIGPIPE
handling, instead of forcing them to undo llvm's SIGPIPE handler
registration (which is brittle).
The current behavior is preserved for all llvm-derived tools (except
lldb) by means of a default-`true` flag in the InitLLVM constructor.
This prevents "IO error" crashes in long-lived processes (lldb is the
motivating example) which both a) load llvm as a dynamic library and b)
*really* need to ignore SIGPIPE.
As llvm signal handlers can be installed when calling into libclang
(say, via RemoveFileOnSignal), thereby overriding a previous SIG_IGN for
SIGPIPE, there is no clean way to opt-out of "exit-on-SIGPIPE" in the
current model.
Differential Revision: https://reviews.llvm.org/D70277
This reverts commit 32ce14e55e.
In post-commit review, Pavel pointed out that there's a simpler way to
ignore SIGPIPE in lldb that doesn't rely on llvm's handlers.
This roughly mimics `std::thread(...).detach()` except it allows to
customize the stack size. Required for https://reviews.llvm.org/D50993.
I've decided against reusing the existing `llvm_execute_on_thread` because
it's not obvious what to do with the ownership of the passed
function/arguments:
1. If we pass possibly owning functions data to `llvm_execute_on_thread`,
we'll lose the ability to pass small non-owning non-allocating functions
for the joining case (as it's used now). Is it important enough?
2. If we use the non-owning interface in the new use case, we'll force
clients to transfer ownership to the spawned thread manually, but
similar code would still have to exist inside
`llvm_execute_on_thread(_async)` anyway (as we can't just pass the same
non-owning pointer to pthreads and Windows implementations, and would be
forced to wrap it in some structure, and deal with its ownership.
Patch by Dmitry Kozhevnikov!
Differential Revision: https://reviews.llvm.org/D51103
Works on this dependency chain:
ArrayRef.h ->
Hashing.h -> --CUT--
Host.h ->
StringMap.h / StringRef.h
ArrayRef is very popular, but Host.h is rarely needed. Move the
IsBigEndianHost constant to SwapByteOrder.h. Clients of that header are
more likely to need it.
llvm-svn: 375316
Occasionally, during test teardown, LLDB writes to a closed pipe.
Sometimes the communication is inherently unreliable, so LLDB tries to
avoid being killed due to SIGPIPE (it calls `signal(SIGPIPE, SIG_IGN)`).
However, LLVM's default SIGPIPE behavior overrides LLDB's, causing it to
exit with IO_ERR.
Opt LLDB out of the default SIGPIPE behavior. I expect that this will
resolve some LLDB test suite flakiness (tests randomly failing with
IO_ERR) that we've seen since r344372.
rdar://55750240
Differential Revision: https://reviews.llvm.org/D69148
llvm-svn: 375288
After r361885, realPathFromHandle() ends up getting called on the working
directory on each Clang invocation. This unveiled that the code didn't work for
paths on network shares.
For example, if one maps the local dir c:\src\tmp to x:
net use x: \\localhost\c$\tmp
and run e.g. "clang -c foo.cc" in x:\, realPathFromHandle will get
\\?\UNC\localhost\c$\src\tmp\ back from GetFinalPathNameByHandleW, and would
strip off the initial \\?\ prefix, ending up with a path that doesn't work.
This patch makes the prefix stripping a little smarter to handle this case.
Differential revision: https://reviews.llvm.org/D67166
llvm-svn: 371035
Summary:
There was a subtle, but pretty important difference between the Slice
and regular versions of this function. The Slice function was
zero-initializing the rest of the buffer when the read syscall returned
less bytes than expected, while the regular function did not.
This patch removes the inconsistency by making both functions *not*
zero-initialize the buffer. The zeroing code is moved to the
MemoryBuffer class, which is currently the only user of this code. This
makes the API more consistent, and the code shorter.
While in there, I also refactor the functions to return the number of
bytes through the regular return value (via Expected<size_t>) instead of
a separate by-ref argument.
Reviewers: aganea, rnk
Subscribers: kristina, Bigcheese, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66471
llvm-svn: 369627
Summary:
The windows version implementation of readNativeFileSlice, was trying to
match the POSIX behavior of not treating EOF as an error, but it was
only handling the case of reading from a pipe. Attempting to read past
the end of a regular file returns a slightly different error code, which
needs to be handled too. This patch adds ERROR_HANDLE_EOF to the list of
error codes to be treated as an end of file, and adds some unit tests
for the API.
This issue was found while attempting to land D66224, which caused a bunch of
lldb tests to start failing on windows.
Reviewers: rnk, aganea
Subscribers: kristina, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66344
llvm-svn: 369269
This should have the same semantics. We use std::shared_mutex instead on
MSVC and C++17, std::shared_timed_mutex is less efficient than our
custom implementation on Windows, std::shared_mutex should be faster.
llvm-svn: 369018
- Remove support for non-recursive mutexes. This was unused.
- The std::recursive_mutex is now created/destroyed unconditionally.
Locking is still only done if threading is enabled.
- Alias SmartScopedLock to std::lock_guard.
This should make no semantic difference on the existing APIs.
llvm-svn: 368158
Support SIGINFO (and SIGUSR1 for POSIX purposes) to tell what
long-running jobs are doing, as inspired by BSD tools (including on
macOS), by dumping the current PrettyStackTrace.
This adds a new kind of signal handler for non-fatal "info" signals,
similar to the "interrupt" handler that already exists for SIGINT
(Ctrl-C). It then uses that handler to update a "generation count"
managed by the PrettyStackTrace infrastructure, which is then checked
whenever a PrettyStackTraceEntry is pushed or popped on each
thread. If the generation has changed---i.e. if the user has pressed
Ctrl-T---the stack trace is dumped, though unfortunately it can't
include the deepest entry because that one is currently being
constructed/destructed.
https://reviews.llvm.org/D63750
llvm-svn: 365911
There is currently an EPERM error when a regular user executes `llvm-objcopy a.o /dev/null`.
Worse, root can even change the mode bits of /dev/null.
Fix it by checking if the output file is special.
A new overload of llvm::sys::fs::setPermissions with FD as the parameter
is added. Users should provide `perm & ~umask` as the parameter if they
intend to respect umask.
The existing overload of llvm::sys::fs::setPermissions may be deleted if
we can find an implementation of fchmod() on Windows. fchmod() is
usually better than chmod() because it saves syscalls and can avoid race
condition.
Reviewed By: jakehehrlich, jhenderson
Differential Revision: https://reviews.llvm.org/D64236
llvm-svn: 365753
Summary:
On Windows, Posix integer file descriptors are a compatibility layer
over native file handles provided by the C runtime. There is a hard
limit on the maximum number of file descriptors that a process can open,
and the limit is 8192. LLD typically doesn't run into this limit because
it opens input files, maps them into memory, and then immediately closes
the file descriptor. This prevents it from running out of FDs.
For various reasons, I'd like to open handles to every input file and
keep them open during linking. That requires migrating MemoryBuffer over
to taking open native file handles instead of integer FDs.
Reviewers: aganea, Bigcheese
Reviewed By: aganea
Subscribers: smeenai, silvas, mehdi_amini, hiraditya, steven_wu, dexonsmith, dang, llvm-commits, zturner
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63453
llvm-svn: 365588
Summary: This patch changes fs::setPermissions to optionally set permissions while respecting the umask. It also adds the function fs::getUmask() which returns the current umask.
Reviewers: jhenderson, rupprecht, aprantl, lhames
Reviewed By: jhenderson, rupprecht
Subscribers: sanaanajjar231288, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63583
llvm-svn: 364621
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
This reverts commit 10d2e88e87150a35dc367ba30716189d2af26774.
This is causing some test failures for some reason, reverting
while I investigate.
llvm-svn: 334354
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
These used to be set in the old autoconf build, but the cmake build has had a
"TODO: actually check for these" comment since it was checked in, and they
were set to 1 on mingw unconditionally. It seems safe to say that they always
exist under mingw, so just remove them and assume they're set exactly when on
mingw (with msvc, we use `pragma comment` instead of linking these via flags).
llvm-svn: 328992
This is like MemoryBuffer (read-only) and WritableMemoryBuffer
(writable private), but where the underlying file can be modified
after writing. This is useful when you want to open a file, make
some targeted edits, and then write it back out.
Differential Revision: https://reviews.llvm.org/D44230
llvm-svn: 327057
This is the second part of recommit of r325224. The previous part was
committed in r325426, which deals with C++ memory allocation. Solution
for C memory allocation involved functions `llvm::malloc` and similar.
This was a fragile solution because it caused ambiguity errors in some
cases. In this commit the new functions have names like `llvm::safe_malloc`.
The relevant part of original comment is below, updated for new function
names.
Analysis of fails in the case of out of memory errors can be tricky on
Windows. Such error emerges at the point where memory allocation function
fails, but manifests itself when null pointer is used. These two points
may be distant from each other. Besides, next runs may not exhibit
allocation error.
In some cases memory is allocated by a call to some of C allocation
functions, malloc, calloc and realloc. They are used for interoperability
with C code, when allocated object has variable size and when it is
necessary to avoid call of constructors. In many calls the result is not
checked for null pointer. To simplify checks, new functions are defined
in the namespace 'llvm': `safe_malloc`, `safe_calloc` and `safe_realloc`.
They behave as corresponding standard functions but produce fatal error if
allocation fails. This change replaces the standard functions like 'malloc'
in the cases when the result of the allocation function is not checked
for null pointer.
Finally, there are plain C code, that uses malloc and similar functions. If
the result is not checked, assert statement is added.
Differential Revision: https://reviews.llvm.org/D43010
llvm-svn: 325551
There is a latent Windows kernel bug, the exact trigger
conditions are not well understood, which can cause a file
to be correctly written, but unable to be correctly read.
The workaround appears to be simply calling FlushFileBuffers.
Differential Revision: https://reviews.llvm.org/D42925
llvm-svn: 325274
Analysis of fails in the case of out of memory errors can be tricky on
Windows. Such error emerges at the point where memory allocation function
fails, but manifests itself when null pointer is used. These two points
may be distant from each other. Besides, next runs may not exhibit
allocation error.
Usual programming practice does not require checking result of 'operator
new' because it throws 'std::bad_alloc' in the case of allocation error.
However, LLVM is usually built with exceptions turned off, so 'new' can
return null pointer. This change installs custom new handler, which causes
fatal error in the case of out of memory. The handler is installed
automatically prior to call to 'main' during construction of a static
object defined in 'lib/Support/ErrorHandling.cpp'. If the application does
not use this file, the handler may be installed manually by a call to
'llvm::install_out_of_memory_new_handler', declared in
'include/llvm/Support/ErrorHandling.h".
There are calls to C allocation functions, malloc, calloc and realloc.
They are used for interoperability with C code, when allocated object has
variable size and when it is necessary to avoid call of constructors. In
many calls the result is not checked against null pointer. To simplify
checks, new functions are defined in the namespace 'llvm' with the
same names as these C function. These functions produce fatal error if
allocation fails. User should use 'llvm::malloc' instead of 'std::malloc'
in order to use the safe variant. This change replaces 'std::malloc'
in the cases when the result of allocation function is not checked against
null pointer.
Finally, there are plain C code, that uses malloc and similar functions. If
the result is not checked, assert statements are added.
Differential Revision: https://reviews.llvm.org/D43010
llvm-svn: 325224
Without this when lld failed to replace the output file it would leave
the temporary behind. The problem is that the existing logic is
- cancel the delete flag
- rename
We have to cancel first to avoid renaming and then crashing and
deleting the old version. What is missing then is deleting the
temporary file if the rename fails.
This can be an issue on both unix and windows, but I am not sure how
to cause the rename to fail reliably on unix. I think it can be done
on ZFS since it has an ACL system similar to what windows uses, but
adding support for checking that in llvm-lit is probably not worth it.
llvm-svn: 319786
Removes AllocateRWX, setWritable and setExecutable from sys::Memory and
standardizes on allocateMappedMemory / protectMappedMemory. The
allocateMappedMemory method is updated to request full permissions for memory
blocks so that they can be marked executable later.
llvm-svn: 318464
Summary:
zturner suggested that mapped_file_region::init() on Windows seems to
create mappings that are larger than they need to be: Offset+Size
instead of Size. Indeed, that appears to be the case. I confirmed that
tests pass with mappings of just Size bytes, and fail with Size-1
bytes, suggesting that Size is indeed the correct value.
Reviewers: amccarth, zturner
Reviewed By: zturner
Subscribers: hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D39876
llvm-svn: 317850
Summary:
The removed code checks that we are able to handle a 64-bit number, but
the code we're calling takes two dwords (for a total of 64 bits), so this
is always true.
Reviewers: zturner, rnk, majnemer, compnerd
Reviewed By: zturner
Subscribers: amccarth, hiraditya, lebedev.ri, llvm-commits
Differential Revision: https://reviews.llvm.org/D39263
llvm-svn: 316814
In r315079 I added a check for the ERROR_CALL_NOT_IMPLEMENTED error
code, but it turns out earlier versions of Wine just returned false
without setting any error code.
This patch handles the unset error code case.
llvm-svn: 315597
In r315079, fs::rename was reimplemented in terms of CreateFile and
SetFileInformationByHandle. Unfortunately, the latter isn't supported by
Wine. This adds a fallback to MoveFileEx for that case.
Differential Revision: https://reviews.llvm.org/D38817
llvm-svn: 315520
This allows clients to avoid an unnecessary fs::status() call on each
directory entry. Because the information returned by FindFirstFileEx
is a subset of the information returned by a regular status() call,
I needed to extract a base class from file_status that contains only
that information.
On my machine, this reduces the time required to enumerate a ThinLTO
cache directory containing 520k files from almost 4 minutes to less
than 2 seconds.
Differential Revision: https://reviews.llvm.org/D38716
llvm-svn: 315378
Microsoft's debug implementation of std::copy checks if the destination is an
array and then does some bounds checking. This was causing an assertion
failure in fs::rename_internal which copies to a buffer of the appropriate
size but that's type-punned to an array of length 1 for API compatibility
reasons.
Fix is to make make the destination a pointer rather than an array.
llvm-svn: 315222
The current implementation of rename uses ReplaceFile if the
destination file already exists. According to the documentation for
ReplaceFile, the source file is opened without a sharing mode. This
means that there is a short interval of time between when ReplaceFile
renames the file and when it closes the file during which the
destination file cannot be opened.
This behaviour is not POSIX compliant because rename is supposed
to be atomic. It was also causing intermittent link failures when
linking with a ThinLTO cache; the ThinLTO cache implementation expects
all cache files to be openable.
This patch addresses that problem by re-implementing rename
using CreateFile and SetFileInformationByHandle. It is roughly a
reimplementation of ReplaceFile with a better sharing policy as well
as support for renaming in the case where the destination file does
not exist.
This implementation is still not fully POSIX. Specifically in the case
where the destination file is open at the point when rename is called,
there will be a short interval of time during which the destination
file will not exist. It isn't clear whether it is possible to avoid
this using the Windows API.
Differential Revision: https://reviews.llvm.org/D38570
llvm-svn: 315079
Summary:
Change the type of the Redirects parameter of llvm::sys::ExecuteAndWait,
ExecuteNoWait and other APIs that wrap them from `const StringRef **` to
`ArrayRef<Optional<StringRef>>`, which is safer and simplifies the use of these
APIs (no more local StringRef variables just to get a pointer to).
Corresponding clang changes will be posted as a separate patch.
Reviewers: bkramer
Reviewed By: bkramer
Subscribers: vsk, llvm-commits
Differential Revision: https://reviews.llvm.org/D37563
llvm-svn: 313155
Alexandre Ganea
