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
It's been reported
<http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20180611/559616.html>
that template argument deduction for RetryAfterSignal fails if open is
not prefixed with "::".
This should help us build correctly on those platforms and explicitly
specifying the namespace is more correct anyway.
llvm-svn: 334403
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
These are necessary changes to support building LLVM for Fuchsia.
While these are not sufficient to run on Fuchsia, they are still
useful when cross-compiling LLVM libraries and runtimes for Fuchsia.
Differential Revision: https://reviews.llvm.org/D46345
llvm-svn: 331423
The autoconf manual: "This macro is obsolescent, as all current systems with
directory libraries have <dirent.h>. New programs need not use this macro."
llvm-svn: 328989
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
According to the docs on opegroup.org, the function can return
EINVAL if:
The len argument is less than zero, or the offset argument is less
than zero, or the underlying file system does not support this
operation.
I'd say it's a peculiar choice (when EONOTSUPP is right there), but
let's keep POSIX happy for now. This was independently discovered
by Mark Millard (on FreeBSD/ZFS).
Quickly ack'ed by Rui on IRC.
llvm-svn: 317535
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
Summary:
Found when testing stage-2 build with D38101.
```
In file included from /build/llvm/lib/Support/Path.cpp:1045:
/build/llvm/lib/Support/Unix/Path.inc:648:14: error: comparison 'uint64_t' (aka 'unsigned long') > 18446744073709551615 is always false [-Werror,-Wtautological-constant-compare]
if (length > std::numeric_limits<size_t>::max()) {
~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
```
`size_t` is `uint64_t` here, apparently, thus any `uint64_t` value
always fits into `size_t`.
Initial patch was to use some preprocessor logic to
not check if the size is known to fit at compile time.
But Zachary Turner suggested using this approach.
Reviewers: Bigcheese, rafael, zturner, mehdi_amini
Reviewed by (via email): zturner
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D38132
llvm-svn: 314312
Summary:
It was added to support clang warnings about includes with case
mismatches, but it ended up not being necessary.
Reviewers: twoh, rafael
Subscribers: hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D36328
llvm-svn: 310078
The difference from the previous version is the use of decltype, as the
implementation of std::result_of in libc++ did not work correctly for
variadic function like open(2).
Original summary:
This function retries an operation if it was interrupted by a signal
(failed with EINTR). It's inspired by the TEMP_FAILURE_RETRY macro in
glibc, but I've turned that into a template function. I've also added a
fail-value argument, to enable the function to be used with e.g.
fopen(3), which is documented to fail for any reason that open(2) can
fail (which includes EINTR).
The main user of this function will be lldb, but there were also a
couple of uses within llvm that I could simplify using this function.
Reviewers: zturner, silvas, joerg
Subscribers: mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D33895
llvm-svn: 306671
The fix in r306003 uncovered a pretty fundamental problem that libc++
implementation of std::result_of does not handle the prototype of
open(2) correctly (presumably because it contains ...). This makes the
whole function unusable in its current form, so I am also reverting the
original commit (r305892), which introduced the function, at least until
I figure out a way to solve the libc++ issue.
llvm-svn: 306005
Summary:
This function retries an operation if it was interrupted by a signal
(failed with EINTR). It's inspired by the TEMP_FAILURE_RETRY macro in
glibc, but I've turned that into a template function. I've also added a
fail-value argument, to enable the function to be used with e.g.
fopen(3), which is documented to fail for any reason that open(2) can
fail (which includes EINTR).
The main user of this function will be lldb, but there were also a
couple of uses within llvm that I could simplify using this function.
Reviewers: zturner, silvas, joerg
Subscribers: mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D33895
llvm-svn: 305892
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
Summary:
Solaris-specific implementation for llvm::sys::fs::is_local_impl.
FStype pattern matching might be a bit unreliable, but at least it fixes the build failure.
Reviewers: mgorny, nlopes, llvm-commits, krytarowski
Reviewed By: krytarowski
Subscribers: voskresensky.vladimir, krytarowski
Differential Revision: https://reviews.llvm.org/D33695
llvm-svn: 304412
driver-mode recognition in clang (this is because the sysctl method
always returns one and only one executable path, even for an executable
with multiple links):
Fix DynamicLibraryTest.cpp on FreeBSD and NetBSD
Summary:
After rL301562, on FreeBSD the DynamicLibrary unittests fail, because
the test uses getMainExecutable("DynamicLibraryTests", Ptr), and since
the path does not contain any slashes, retrieving the main executable
will not work.
Reimplement getMainExecutable() for FreeBSD and NetBSD using sysctl(3),
which is more reliable than fiddling with relative or absolute paths.
Also add retrieval of the original argv[] from the GoogleTest framework,
to use as a fallback for other OSes.
Reviewers: emaste, marsupial, hans, krytarowski
Reviewed By: krytarowski
Subscribers: krytarowski, llvm-commits
Differential Revision: https://reviews.llvm.org/D33171
llvm-svn: 303285
Summary:
After rL301562, on FreeBSD the DynamicLibrary unittests fail, because
the test uses getMainExecutable("DynamicLibraryTests", Ptr), and since
the path does not contain any slashes, retrieving the main executable
will not work.
Reimplement getMainExecutable() for FreeBSD and NetBSD using sysctl(3),
which is more reliable than fiddling with relative or absolute paths.
Also add retrieval of the original argv[] from the GoogleTest framework,
to use as a fallback for other OSes.
Reviewers: emaste, marsupial, hans, krytarowski
Reviewed By: krytarowski
Subscribers: krytarowski, llvm-commits
Differential Revision: https://reviews.llvm.org/D33171
llvm-svn: 303015
This is something of an edge case, but when the $HOME environment
variable is not set, we can still look in the password database
to get the current user's home directory.
Added a test for this by getting the value of $HOME, then unsetting
it, then calling home_directory() and verifying that it succeeds
and that the value is the same as what we originally read from
the environment.
llvm-svn: 298513
This change adds support for functions to set and get file permissions, in a similar manner to the C++17 permissions() function in <filesystem>. The setter uses chmod on Unix systems and SetFileAttributes on Windows, setting the permissions as passed in. The getter simply uses the existing status() function.
Prior to this change, status() would always return an unknown value for the permissions on a Windows file, making it impossible to test the new function on Windows. I have therefore added support for this as well. On Linux, prior to this change, the permissions included the file type, which should actually be accessed via a different member of the file_status class.
Note that on Windows, only the *_write permission bits have any affect - if any are set, the file is writable, and if not, the file is read-only. This is in common with what MSDN describes for their behaviour of std::filesystem::permissions(), and also what boost::filesystem does.
The motivation behind this change is so that we can easily test behaviour on read-only files in LLVM unit tests, but I am sure that others may find it useful in some situations.
Reviewers: zturner, amccarth, aaron.ballman
Differential Revision: https://reviews.llvm.org/D30736
llvm-svn: 297945
LLVM already has real_path like functionality, but it is
cumbersome to use and involves clean up after (e.g. you have
to call openFileForRead, then close the resulting FD).
Furthermore, on Windows it doesn't work for directories since
opening a directory and opening a file require slightly
different flags.
So I add a simple function `real_path` which works for all
paths on all platforms and has a simple to use interface.
In doing so, I add the ability to opt in to resolving tilde
expressions (e.g. ~/foo), which are normally handled by
the shell.
Differential Revision: https://reviews.llvm.org/D30668
llvm-svn: 297483
We already have a function create_directories() which can create
an entire tree, and remove() which can remove an empty directory,
but we do not have remove_directories() which can remove an entire
tree. This patch adds such a function.
Because removing a directory tree can have dangerous consequences
when the tree contains a directory symlink, the patch here updates
the existing directory_iterator construct to optionally not follow
symlinks (previously it would always follow symlinks). The delete
algorithm uses this flag so that for symlinks, only the links are
removed, and not the targets.
On Windows this is implemented with SHFileOperation, which also
does not recurse into symbolic links or junctions.
Differential Revision: https://reviews.llvm.org/D30676
llvm-svn: 297314
The function for distinguishing local and remote files added in r295768
unconditionally uses linux/magic.h header to provide necessary
filesystem magic numbers. However, in kernel headers predating 2.6.18
the magic numbers are spread throughout multiple include files.
Furthermore, LLVM did not require kernel headers being installed so far.
To increase the portability across different versions of Linux kernel
and different Linux systems, add CMake header checks for linux/magic.h
and -- if it is missing -- the linux/nfs_fs.h and linux/smb.h headers
which contained the numbers previously.
Furthermore, since the numbers are static and the feature does not seem
critical enough to make LLVM require kernel headers at all, add fallback
constants for the case when none of the necessary headers is available.
Differential Revision: https://reviews.llvm.org/D30261
llvm-svn: 295854
Since I'm only seeing failures on OSX, and it's saying
permission denied, I'm suspecting this is due to the addition
of the MAP_RESILIENT_CODESIGN and/or MAP_RESILIENT_MEDIA flags.
Speculatively trying to remove those to get the bots working.
llvm-svn: 295770
Committing after fixing suggested changes and tested release/debug builds on
x86_64-linux and arm/aarch64 builds.
Differential revision: https://reviews.llvm.org/D29042
llvm-svn: 293850
Summary:
Use the O_CLOEXEC flag only when it is available. Some old systems (e.g.
SLES10) do not support this flag. POSIX explicitly guarantees that this
flag can be checked for using #if, so there is no need for a CMake
check.
In case O_CLOEXEC is not supported, fall back to fcntl(FD_CLOEXEC)
instead.
Reviewers: rnk, rafael, mgorny
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D28894
llvm-svn: 292912
Summary:
This adds a cross-platform way of setting the current working directory
analogous to the existing current_path() function used for retrieving
it. The function will be used in lldb.
Reviewers: rafael, silvas, zturner
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D29035
llvm-svn: 292907
Summary:
This makes the file descriptors on unix platform non-inheritable (O_CLOEXEC).
There is no change in behavior on windows, as the handles were already
non-inheritable there.
Reviewers: rnk, rafael
Subscribers: llvm-commits, mgorny
Differential Revision: https://reviews.llvm.org/D28854
llvm-svn: 292401
Summary:
The motivation is to support better the -object_path_lto option on
Darwin. The linker needs to write down the generate object files on
disk for later use by lldb or dsymutil (debug info are not present
in the final binary). We're moving this into libLTO so that we can
be smarter when a cache is enabled and hard-link when possible
instead of duplicating the files.
Reviewers: tejohnson, deadalnix, pcc
Subscribers: dexonsmith, llvm-commits
Differential Revision: https://reviews.llvm.org/D27507
llvm-svn: 289631
If we don't have futimens(), we fall back to futimes(), which only supports
microsecond timestamps. In that case, we need to explicitly cast away the extra
precision in setLastModificationAndAccessTime().
llvm-svn: 284977
Summary:
This is a follow-up to D25416. It removes all usages of TimeValue from
llvm/Support library (except for the actual TimeValue declaration), and replaces
them with appropriate usages of std::chrono. To facilitate this, I have added
small utility functions for converting time points and durations into appropriate
OS-specific types (FILETIME, struct timespec, ...).
Reviewers: zturner, mehdi_amini
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D25730
llvm-svn: 284966
