This is currently used by clang to lock access to modules; improve the
error message so that clang can use better output messages from locking
error issues.
rdar://problem/26529101
Differential Review: http://reviews.llvm.org/D20942
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@271755 91177308-0d34-0410-b5e6-96231b3b80d8
Reapplies r241005 after fixing the build on non-Mac platforms. Original
commit message below.
The hostname can be very unstable when there are many machines on the
network competing for the same name. Using the hardware UUID makes it
less likely to have collisions or to consider files written by the
current host to be owned by a different one at a later time.
rdar://problem/21512307
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241012 91177308-0d34-0410-b5e6-96231b3b80d8
The hostname can be very unstable when there are many machines on the
network competing for the same name. Using the hardware UUID makes it
less likely to have collisions or to consider files written by the
current host to be owned by a different one at a later time.
rdar://problem/21512307
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241005 91177308-0d34-0410-b5e6-96231b3b80d8
Make sure to remove the unique lock file, which is what the .lock
symlink points to, if there is a signal while the lock is held. This
will release the lock, since the symlink will point to nothing (already
tested in unit tests). For good measure, also clean up the unique lock
file if there is an error or signal before the lock is acquired.
I will add a clang test.
rdar://problem/21512307
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240967 91177308-0d34-0410-b5e6-96231b3b80d8
Now that SmallString is a first-class citizen, most SmallString::str()
calls are not required. This patch removes a whole bunch of them, yet
there are lots more.
There are two use cases where str() is really needed:
1) To use one of StringRef member functions which is not available in
SmallString.
2) To convert to std::string, as StringRef implicitly converts while
SmallString do not. We may wish to change this, but it may introduce
ambiguity.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232622 91177308-0d34-0410-b5e6-96231b3b80d8
This is true in clang, and let's us remove the problematic code that
waits around for the original file and then times out if it doesn't get
created in short order. This caused any 'dead' lock file or legitimate
time out to cause a cascade of timeouts in any processes waiting on the
same lock (even if they only just showed up).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229881 91177308-0d34-0410-b5e6-96231b3b80d8
5 minutes is an eternity, so try to strike a better balance between
waiting long enough for any reasonable module build and not so long that
users kill the process because they think it's hanging.
Also give the client a way to delete the lock file after a timeout.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228603 91177308-0d34-0410-b5e6-96231b3b80d8
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).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217625 91177308-0d34-0410-b5e6-96231b3b80d8
Instead of moving out the data in a ErrorOr<std::unique_ptr<Foo>>, get
a reference to it.
Thanks to David Blaikie for the suggestion.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214516 91177308-0d34-0410-b5e6-96231b3b80d8
While std::error_code itself seems to work OK in all platforms, there
are few annoying differences with regards to the std::errc enumeration.
This patch adds a simple llvm enumeration, which will hopefully avoid build
breakages in other platforms and surprises as we get more uses of
std::error_code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210920 91177308-0d34-0410-b5e6-96231b3b80d8
The idea of this patch is to turn llvm/Support/system_error.h into a
transitional header that just brings in the erorr_code api to the llvm
namespace. I will remove it shortly afterwards.
The cases where the general idea needed some tweaking:
* std::errc is a namespace in msvc, so we cannot use "using std::errc". I could
add an #ifdef, but there were not that many uses, so I just added std:: to
them in this patch.
* Template specialization had to be moved to the std namespace in this
patch set already.
* The msvc implementation of default_error_condition doesn't seem to
provide the same transformations as we need. Not too surprising since
the standard doesn't actually say what "equivalent" means. I fixed the
problem by keeping our old mapping and using it at error_code
construction time.
Despite these shortcomings I think this is still a good thing. Some reasons:
* The different implementations of system_error might improve over time.
* It removes 925 lines of code from llvm already.
* It removes 6313 bytes from the text segment of the clang binary when
it is built with gcc and 2816 bytes when building with clang and
libstdc++.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210687 91177308-0d34-0410-b5e6-96231b3b80d8
Vassil Vassilev
Eugene Zelenko
Bruno Cardoso Lopes
Ben Langmuir
Benjamin Kramer
Yaron Keren
Argyrios Kyrtzidis
Rafael Espindola
Craig Topper