[cfe-commits] r173542 - Since we're stuck with realpath for the header <-> module mapping,

[Douglas Gregor]

On Mar 4, 2013, at 12:15 PM, Chad Rosier <mcrosier at apple.com> wrote:

> 
> On Jan 25, 2013, at 4:55 PM, Douglas Gregor <dgregor at apple.com> wrote:
> 
>> Author: dgregor
>> Date: Fri Jan 25 18:55:12 2013
>> New Revision: 173542
>> 
>> URL: http://llvm.org/viewvc/llvm-project?rev=173542&view=rev
>> Log:
>> Since we're stuck with realpath for the header <-> module mapping,
>> factor the realpath calls into FileManager::getCanonicalName() so we
>> can cache the results of this epically slow operation. 5% speedup on
>> my modules test, and realpath drops out of the profile.
>> 
>> Modified:
>>    cfe/trunk/include/clang/Basic/FileManager.h
>>    cfe/trunk/lib/Basic/FileManager.cpp
>>    cfe/trunk/lib/Lex/HeaderSearch.cpp
>>    cfe/trunk/lib/Lex/ModuleMap.cpp
>> 
>> Modified: cfe/trunk/include/clang/Basic/FileManager.h
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/FileManager.h?rev=173542&r1=173541&r2=173542&view=diff
>> ==============================================================================
>> --- cfe/trunk/include/clang/Basic/FileManager.h (original)
>> +++ cfe/trunk/include/clang/Basic/FileManager.h Fri Jan 25 18:55:12 2013
>> @@ -17,6 +17,7 @@
>> 
>> #include "clang/Basic/FileSystemOptions.h"
>> #include "clang/Basic/LLVM.h"
>> +#include "llvm/ADT/DenseMap.h"
>> #include "llvm/ADT/IntrusiveRefCntPtr.h"
>> #include "llvm/ADT/OwningPtr.h"
>> #include "llvm/ADT/SmallVector.h"
>> @@ -152,6 +153,12 @@ class FileManager : public RefCountedBas
>>   /// \see SeenDirEntries
>>   llvm::StringMap<FileEntry*, llvm::BumpPtrAllocator> SeenFileEntries;
>> 
>> +  /// \brief The canonical names of directories.
>> +  llvm::DenseMap<const DirectoryEntry *, llvm::StringRef> CanonicalDirNames;
>> +
>> +  /// \brief Storage for canonical names that we have computed.
>> +  llvm::BumpPtrAllocator CanonicalNameStorage;
>> +
>>   /// \brief Each FileEntry we create is assigned a unique ID #.
>>   ///
>>   unsigned NextFileUID;
>> @@ -257,6 +264,13 @@ public:
>>   static void modifyFileEntry(FileEntry *File, off_t Size,
>>                               time_t ModificationTime);
>> 
>> +  /// \brief Retrieve the canonical name for a given directory.
>> +  ///
>> +  /// This is a very expensive operation, despite its results being cached,
>> +  /// and should only be used when the physical layout of the file system is
>> +  /// required, which is (almost) never.
>> +  StringRef getCanonicalName(const DirectoryEntry *Dir);
>> +
>>   void PrintStats() const;
>> };
>> 
>> 
>> Modified: cfe/trunk/lib/Basic/FileManager.cpp
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Basic/FileManager.cpp?rev=173542&r1=173541&r2=173542&view=diff
>> ==============================================================================
>> --- cfe/trunk/lib/Basic/FileManager.cpp (original)
>> +++ cfe/trunk/lib/Basic/FileManager.cpp Fri Jan 25 18:55:12 2013
>> @@ -40,6 +40,11 @@
>> #define S_ISFIFO(x) (0)
>> #endif
>> #endif
>> +#if defined(LLVM_ON_UNIX)
>> +#if defined(__linux__)
>> +#include <linux/limits.h>
>> +#endif
>> +#endif
>> using namespace clang;
>> 
>> // FIXME: Enhance libsystem to support inode and other fields.
>> @@ -620,6 +625,29 @@ void FileManager::modifyFileEntry(FileEn
>>   File->ModTime = ModificationTime;
>> }
>> 
>> +StringRef FileManager::getCanonicalName(const DirectoryEntry *Dir) {
>> +  // FIXME: use llvm::sys::fs::canonical() when it gets implemented
>> +#ifdef LLVM_ON_UNIX
>> +  llvm::DenseMap<const DirectoryEntry *, llvm::StringRef>::iterator Known
>> +    = CanonicalDirNames.find(Dir);
>> +  if (Known != CanonicalDirNames.end())
>> +    return Known->second;
>> +
>> +  StringRef CanonicalName(Dir->getName());
>> +  char CanonicalNameBuf[PATH_MAX];
>> +  if (realpath(Dir->getName(), CanonicalNameBuf)) {
>> +    unsigned Len = strlen(CanonicalNameBuf);
>> +    char *Mem = static_cast<char *>(CanonicalNameStorage.Allocate(Len, 1));
>> +    memcpy(Mem, CanonicalNameBuf, Len);
>> +    CanonicalName = StringRef(Mem, Len);
>> +  }
>> +
>> +  CanonicalDirNames.insert(std::make_pair(Dir, CanonicalName));
>> +  return CanonicalName;
>> +#else
>> +  return StringRef(Dir->getName());
>> +#endif
>> +}
>> 
>> void FileManager::PrintStats() const {
>>   llvm::errs() << "\n*** File Manager Stats:\n";
>> 
>> Modified: cfe/trunk/lib/Lex/HeaderSearch.cpp
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Lex/HeaderSearch.cpp?rev=173542&r1=173541&r2=173542&view=diff
>> ==============================================================================
>> --- cfe/trunk/lib/Lex/HeaderSearch.cpp (original)
>> +++ cfe/trunk/lib/Lex/HeaderSearch.cpp Fri Jan 25 18:55:12 2013
>> @@ -268,6 +268,10 @@ const FileEntry *DirectoryLookup::Lookup
>>   return Result;
>> }
>> 
>> +/// FIXME: HACK HACK HACK!
>> +static llvm::DenseMap<const DirectoryEntry *, const DirectoryEntry *>
>> +  TopFrameworkDirs;
>> +
> 
> Hi Doug,
> Is the TopFrameworkDirs map actually used?

Thankfully, no. Removed in r176535.

	- Doug


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