Add lightweight shim "clang::StatSysCallCache" that caches 'stat' system calls
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
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@ -22,6 +22,7 @@
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#include <string>
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// FIXME: Enhance libsystem to support inode and other fields in stat.
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#include <sys/types.h>
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#include <sys/stat.h>
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namespace clang {
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class FileManager;
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@ -68,6 +69,14 @@ public:
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}
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};
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// FIXME: This is a lightweight shim that is used by FileManager to cache
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// 'stat' system calls. We will use it with PTH to identify if caching
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// stat calls in PTH files is a performance win.
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class StatSysCallCache {
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public:
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virtual ~StatSysCallCache() {}
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virtual int stat(const char *path, struct stat *buf) = 0;
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};
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/// FileManager - Implements support for file system lookup, file system
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/// caching, and directory search management. This also handles more advanced
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@ -97,8 +106,15 @@ class FileManager {
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// Statistics.
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unsigned NumDirLookups, NumFileLookups;
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unsigned NumDirCacheMisses, NumFileCacheMisses;
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// Caching.
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StatSysCallCache *StatCache;
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int stat_cached(const char* path, struct stat* buf) {
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return StatCache ? StatCache->stat(path, buf) : stat(path, buf);
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}
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public:
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FileManager();
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FileManager(StatSysCallCache *statCache = 0);
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~FileManager();
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/// getDirectory - Lookup, cache, and verify the specified directory. This
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@ -29,7 +29,7 @@ using namespace clang;
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#include <sys/stat.h>
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#if defined(_MSC_VER)
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#define S_ISDIR(s) (_S_IFDIR & s)
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#defisstne S_ISDIR(s) (_S_IFDIR & s)
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#endif
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/// NON_EXISTENT_DIR - A special value distinct from null that is used to
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@ -134,10 +134,11 @@ public:
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// Common logic.
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//===----------------------------------------------------------------------===//
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FileManager::FileManager() : UniqueDirs(*new UniqueDirContainer),
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UniqueFiles(*new UniqueFileContainer),
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DirEntries(64), FileEntries(64), NextFileUID(0)
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{
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FileManager::FileManager(StatSysCallCache* statCache)
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: UniqueDirs(*new UniqueDirContainer),
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UniqueFiles(*new UniqueFileContainer),
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DirEntries(64), FileEntries(64), NextFileUID(0),
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StatCache(statCache) {
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NumDirLookups = NumFileLookups = 0;
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NumDirCacheMisses = NumFileCacheMisses = 0;
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}
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@ -145,6 +146,7 @@ FileManager::FileManager() : UniqueDirs(*new UniqueDirContainer),
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FileManager::~FileManager() {
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delete &UniqueDirs;
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delete &UniqueFiles;
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delete StatCache;
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}
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@ -173,7 +175,7 @@ const DirectoryEntry *FileManager::getDirectory(const char *NameStart,
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// Check to see if the directory exists.
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struct stat StatBuf;
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if (stat(InterndDirName, &StatBuf) || // Error stat'ing.
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if (stat_cached(InterndDirName, &StatBuf) || // Error stat'ing.
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!S_ISDIR(StatBuf.st_mode)) // Not a directory?
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return 0;
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@ -246,8 +248,8 @@ const FileEntry *FileManager::getFile(const char *NameStart,
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// Nope, there isn't. Check to see if the file exists.
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struct stat StatBuf;
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//llvm::cerr << "STATING: " << Filename;
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if (stat(InterndFileName, &StatBuf) || // Error stat'ing.
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S_ISDIR(StatBuf.st_mode)) { // A directory?
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if (stat_cached(InterndFileName, &StatBuf) || // Error stat'ing.
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S_ISDIR(StatBuf.st_mode)) { // A directory?
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// If this file doesn't exist, we leave a null in FileEntries for this path.
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//llvm::cerr << ": Not existing\n";
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return 0;
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