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
Serge Pavlov
Zachary Turner
Eric Christopher
Rafael Espindola
Lang Hames
Bob Haarman
Hans Wennborg
Peter Collingbourne
Adrian McCarthy
Roman Lebedev
Alexander Kornienko