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path: root/lib/Serialization/GlobalModuleIndex.cpp
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2013-04-17[Modules] Use global index to improve typo correction performanceArgyrios Kyrtzidis
Typo correction for an unqualified name needs to walk through all of the identifier tables of all modules. When we have a global index, just walk its identifier table only. rdar://13425732 git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179730 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-22<rdar://problem/13479539> Simplify ModuleManager/GlobalModuleIndex ↵Douglas Gregor
interaction to eliminate a pile of extraneous stats(). The refactoring in r177367 introduced a serious performance bug where the "lazy" resolution of module file names in the global module index to actual module file entries in the module manager would perform repeated negative stats(). The new interaction requires the module manager to inform the global module index when a module file has been loaded, eliminating the extraneous stat()s and a bunch of bookkeeping on both sides. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@177750 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-19<rdar://problem/13363214> Eliminate race condition between module rebuild ↵Douglas Gregor
and the global module index. The global module index was querying the file manager for each of the module files it knows about at load time, to prune out any out-of-date information. The file manager would then cache the results of the stat() falls used to find that module file. Later, the same translation unit could end up trying to import one of the module files that had previously been ignored by the module cache, but after some other Clang instance rebuilt the module file to bring it up-to-date. The stale stat() results in the file manager would trigger a second rebuild of the already-up-to-date module, causing failures down the line. The global module index now lazily resolves its module file references to actual AST reader module files only after the module file has been loaded, eliminating the stat-caching race. Moreover, the AST reader can communicate to its caller that a module file is missing (rather than simply being out-of-date), allowing us to simplify the module-loading logic and allowing the compiler to recover if a dependent module file ends up getting deleted. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@177367 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-08Never cache the result of a module file lookup.Douglas Gregor
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@174744 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-06Eliminate a race condition with the global module index.Douglas Gregor
Essentially, a module file on disk could change size between the time we stat() it and the time we open it, and we need to be robust against such a problem. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@174529 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-28ASTReader and profiling statistics indicate that implementing a methodDouglas Gregor
pool in the global module index is not worthwhile. Update comments to limit the scope of the global module index to identifiers. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@173705 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-25Improve coordination between the module manager and the global moduleDouglas Gregor
index, optimizing the operation that skips lookup in modules where we know the identifier will not be found. This makes the global module index optimization actually useful, providing an 8.5% speedup over modules without the global module index for -fsyntax-only. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@173529 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-25Serialization/GlobalModuleIndex.cpp: Fixup r173405, <cstdio>NAKAMURA Takumi
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@173408 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-25Implement the reader of the global module index and wire it into theDouglas Gregor
AST reader. The global module index tracks all of the identifiers known to a set of module files. Lookup of those identifiers looks first in the global module index, which returns the set of module files in which that identifier can be found. The AST reader only needs to look into those module files and any module files not known to the global index (e.g., because they were (re)built after the global index), reducing the number of on-disk hash tables to visit. For an example source I'm looking at, we go from 237844 total identifier lookups into on-disk hash tables down to 126817. Unfortunately, this does not translate into a performance advantage. At best, it's a wash once the global module index has been built, but that's ignore the cost of building the global module index (which is itself fairly large). Profiles show that the global module index code is far less efficient than it should be; optimizing it might give enough of an advantage to justify its continued inclusion. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@173405 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-24clang/GlobalModuleIndex: Don't open the same file twice. Use ↵NAKAMURA Takumi
raw_fd_ostream(fd, ...) instead. FIXME: PathV2::unique_file() is assumed to open the file with binary mode on win32. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@173330 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-23Fix for case-sensitive file systems. UghDouglas Gregor
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@173303 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-23Implement the writer side of the global module index. Douglas Gregor
The global module index is a "global" index for all of the module files within a particular subdirectory in the module cache, which keeps track of all of the "interesting" identifiers and selectors known in each of the module files. One can perform a fast lookup in the index to determine which module files will have more information about entities with a particular name/selector. This information can help eliminate redundant lookups into module files (a serious performance problem) and help with creating auto-import/auto-include Fix-Its. The global module index is created or updated at the end of a translation unit that has triggered a (re)build of a module by scraping all of the .pcm files out of the module cache subdirectory, so it catches everything. As with module rebuilds, we use the file system's atomicity to synchronize. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@173301 91177308-0d34-0410-b5e6-96231b3b80d8