After the open+fstat optimization, files were already opened for FileManager::getBufferForFile() and we closed them after reading them.
The problem was that when -working-directory was passed, the code path that actually reuses & closes the already opened file descriptor
was not followed.
llvm-svn: 127639
This patch contains:
- making some of the existing comments more accurate in the presence
of virtual files/directories.
- renaming some private data members of FileManager to match their roles better.
- creating 'DirectorEntry's for the parent directories of virtual
files, such that we can tell whether two virtual files are from the
same directory. This is useful for injecting virtual files whose
directories don't exist in the real file system.
- minor clean-ups and adding comments for class
FileManager::UniqueDirContainer and FileManager::UniqueFileContainer.
- adding statistics on virtual files to FileManager::PrintStats().
- adding unit tests to verify the existing and new behavior of FileManager.
llvm-svn: 125384
AST/PCH files more lazy:
- Don't preload all of the file source-location entries when reading
the AST file. Instead, load them lazily, when needed.
- Only look up header-search information (whether a header was already
#import'd, how many times it's been included, etc.) when it's needed
by the preprocessor, rather than pre-populating it.
Previously, we would pre-load all of the file source-location entries,
which also populated the header-search information structure. This was
a relatively minor performance issue, since we would end up stat()'ing
all of the headers stored within a AST/PCH file when the AST/PCH file
was loaded. In the normal PCH use case, the stat()s were cached, so
the cost--of preloading ~860 source-location entries in the Cocoa.h
case---was relatively low.
However, the recent optimization that replaced stat+open with
open+fstat turned this into a major problem, since the preloading of
source-location entries would now end up opening those files. Worse,
those files wouldn't be closed until the file manager was destroyed,
so just opening a Cocoa.h PCH file would hold on to ~860 file
descriptors, and it was easy to blow through the process's limit on
the number of open file descriptors.
By eliminating the preloading of these files, we neither open nor stat
the headers stored in the PCH/AST file until they're actually needed
for something. Concretely, we went from
*** HeaderSearch Stats:
835 files tracked.
364 #import/#pragma once files.
823 included exactly once.
6 max times a file is included.
3 #include/#include_next/#import.
0 #includes skipped due to the multi-include optimization.
1 framework lookups.
0 subframework lookups.
*** Source Manager Stats:
835 files mapped, 3 mem buffers mapped.
37460 SLocEntry's allocated, 11215575B of Sloc address space used.
62 bytes of files mapped, 0 files with line #'s computed.
with a trivial program that uses a chained PCH including a Cocoa PCH
to
*** HeaderSearch Stats:
4 files tracked.
1 #import/#pragma once files.
3 included exactly once.
2 max times a file is included.
3 #include/#include_next/#import.
0 #includes skipped due to the multi-include optimization.
1 framework lookups.
0 subframework lookups.
*** Source Manager Stats:
3 files mapped, 3 mem buffers mapped.
37460 SLocEntry's allocated, 11215575B of Sloc address space used.
62 bytes of files mapped, 0 files with line #'s computed.
for the same program.
llvm-svn: 125286
overridden via remapping. Thus, when we create a "virtual" file in the
file manager, we still stat() the real file that lives behind it so
that we can provide proper uniquing based on inodes. This helps keep
the file manager much more consistent.
To take advantage of this when reparsing files in libclang, we disable
the use of the stat() cache when reparsing or performing code
completion, since the stat() cache is very likely to be out of date in
this use case.
llvm-svn: 124971
on that name. Canonicalization eliminates silliness such as "." and
"foo/.." that breaks the uniquing of files in the presence of virtual
files or files whose inode numbers have changed during
parsing/re-parsing. c-index-test isn't able to create this crazy
situation, so I've resorted to testing outside of the Clang
tree. Fixes <rdar://problem/8928220>.
Note that this hackery will go away once we have a real virtual file
system on which we can layer FileManager; the virtual-files hack is
showing cracks.
llvm-svn: 124754
FileManager.cpp: Allow virtual files in nonexistent directories.
FileManager.cpp: Close FileDescriptor for virtual files that correspond to actual files.
FileManager.cpp: Enable virtual files to be created even for files that were flagged as NON_EXISTENT_FILE, e.g. by a prior (unsuccessful) addFile().
ASTReader.cpp: Read a PCH even if the original source files cannot be found.
Add a test for reading a PCH of a file that has been removed and diagnostics referencing that file.
llvm-svn: 124374
followed by an open for every source file we open, probe the file system with
'open' and then do an fstat when it succeeds. open+fstat is faster than
stat+open because the kernel only has to perform the string->inode mapping
once. Presumably it gets faster the deeper in your filesystem a lookup
happens.
For -Eonly on cocoa.h, this reduces system time from 0.042s to 0.039s on
my machine, a 7.7% speedup.
llvm-svn: 120066
pointer that is passed down through the APIs, and make
FileSystemStatCache::get be the one that filters out
directory lookups that hit files. This also paves the
way to have stat queries be able to return opened files.
llvm-svn: 120060
two copies, since they are fundamentally different
operations and the StringRef one should go away
(it shouldn't be part of FileManager at least).
Remove some dead arguments.
llvm-svn: 120013
FileSystemOpts through a ton of apis, simplifying a lot of code.
This also fixes a latent bug in ASTUnit where it would invoke
methods on FileManager without creating one in some code paths
in cindextext.
llvm-svn: 120010
This patch completely defeated the "passing in a prestat'd size
to MemoryBuffer" optimization, leading to an extra fstat call for
every buffer opened, in order to find out if the datestamp and size
of the file on disk matches what is in the stat cache.
I fully admit that I don't completely understand what is going on here:
why punish code when a stat cache isn't in use? what is the point of a
stat cache if you have to turn around and stat stuff to validate it?
To resolve both these issues, just drop the modtime check and check the
file size, which is the important thing anyway. This should also resolve
PR6812, because presumably windows is stable when it comes to file sizes.
If the modtime is actually important, we should get it and keep it on the
first stat.
This eliminates 833 fstat syscalls when processing Cocoa.h, speeding up
system time on -Eonly Cocoa.h from 0.041 to 0.038s.
llvm-svn: 120001
When -working-directory is passed in command line, file paths are resolved relative to the specified directory.
This helps both when using libclang (where we can't require the user to actually change the working directory)
and to help reproduce test cases when the reproduction work comes along.
--FileSystemOptions is introduced which controls how file system operations are performed (currently it just contains
the working directory value if set).
--FileSystemOptions are passed around to various interfaces that perform file operations.
--Opening & reading the content of files should be done only through FileManager. This is useful in general since
file operations will be abstracted in the future for the reproduction mechanism.
FileSystemOptions is independent of FileManager so that we can have multiple translation units sharing the same
FileManager but with different FileSystemOptions.
Addresses rdar://8583824.
llvm-svn: 118203
#pragma once wasn't working on win32 if the header file was included
using a different case.
I tracked down the problem to the fact that clang::FileManager was
caching files using case sensitive string (UniqueFiles) on Windows.
I changed FileManager to cache filename in lower case only.
Doesn't affect UNIX because UNIX uses Inode to uniquely identify files.
unix doesn't use this codepath.
Analysis and patch by Francois Pichet!
llvm-svn: 111866
inconsistent situations if we do, and they are not important for PCH performance
(which currently only needs the stats to construct the initial FileManager
entries).
- No test case, sorry, the machinations are too involved.
This occurs when, for example, the build makes a PCH file and has a header map
or a -I for a directory that does not yet exist. It is possible we will cache
the negative stat on that directory, and then in the build we will never find
header files inside that dir.
For PCH we don't need these stats anyway for performance, so this also makes PCH
files smaller w/ no loss. I hope to eventually eliminate the stat cache
entirely.
llvm-svn: 91082
file. This is accomplished by introducing the notion of a "virtual"
file into the file manager, which provides a FileEntry* for a named
file whose size and modification time are known but which may not
exist on disk.
Added a cute little test that remaps both a .c file and a .h file it
includes to alternative files.
llvm-svn: 90329
only supporting a single stat cache. The immediate benefit of this
change is that we can now generate a PCH/AST file when including
another PCH file; in the future, the chain of stat caches will likely
be useful with multiple levels of PCH files.
llvm-svn: 84263
essentially the same thing we do with pretokenized headers. stat()
caching improves performance of the Cocoa-prefixed "Hello, World" by
45%.
llvm-svn: 70223
- set the 'StatSysCallCache' object using a setter method instead of
FileManager's constructor. This allows the cache to be installed after the
FileManager object is created.
- Add 'file mode' to FileEntry (useful for stat caching)
llvm-svn: 64351
for use by FileManager. FileManager now takes a StatSysCallCache* in its
constructor (which defaults to NULL). This will be used for evaluating whether
or not caching 'stat' system calls in PTH is a performance win. This shim adds
no observable performance impact in the case where the 'StatSysCallCache*' is
null.
llvm-svn: 64345
lib dir and move all the libraries into it. This follows the main
llvm tree, and allows the libraries to be built in parallel. The
top level now enforces that all the libs are built before Driver,
but we don't care what order the libs are built in. This speeds
up parallel builds, particularly incremental ones.
llvm-svn: 48402
Argyrios Kyrtzidis