FileOutputBuffer creates a temp file and on commit atomically
renames the temp file to the destination file. Sometimes we
want to modify an existing file in place, but still have the
atomicity guarantee. To do this we can initialize the contents
of the temp file from the destination file (if it exists), that
way the resulting FileOutputBuffer can have only selective
bytes modified. Committing will then atomically replace the
destination file as desired.
llvm-svn: 335902
clang-format (https://reviews.llvm.org/D33932) to keep primary headers
at the top and handle new utility headers like 'gmock' consistently with
other utility headers.
No other change was made. I did no manual edits, all of this is
clang-format.
This should allow other changes to have more clear and focused diffs,
and is especially motivated by moving some headers into more focused
libraries.
llvm-svn: 304786
If we failed to commit the buffer but did not die to a signal, the temp
file would remain on disk on Windows. Having an open file mapping and
file handle prevents the file from being deleted. I am choosing not to
add an assertion of success on the temp file removal, since virus
scanners and other environmental things can often cause removal to fail
in real world tools.
Also fix more temp file leaks in unit tests.
llvm-svn: 280445
utils/sort_includes.py.
I clearly haven't done this in a while, so more changed than usual. This
even uncovered a missing include from the InstrProf library that I've
added. No functionality changed here, just mechanical cleanup of the
include order.
llvm-svn: 225974
The main difference is the removal of
std::error_code exists(const Twine &path, bool &result);
It was an horribly redundant interface since a file not existing is also a valid
error_code. Now we have an access function that returns just an error_code. This
is the only function that has to be implemented for Unix and Windows. The
functions can_write, exists and can_execute an now just wrappers.
One still has to be very careful using these function to avoid introducing
race conditions (Time of check to time of use).
llvm-svn: 217625
There are a few valid situation where we care about the structure inside a
directory, but not about the directory itself. A simple example is for unit
testing directory traversal.
PathV1 had a function like this, add one to V2 and port existing users of the
created temp file and delete it hack to using it.
llvm-svn: 185059
Since the llvm::sys::fs::map_file_pages() support function it relies on
is not yet implemented on Windows, the unit tests for FileOutputBuffer
are currently conditionalized to run only on unix.
llvm-svn: 161099
