[VFS] vfs::directory_iterator yields path and file type instead of full Status

Summary:
Most callers I can find are using only `getName()`. Type is used by the
recursive iterator.

Now we don't have to call stat() on every listed file (on most platforms).
Exceptions are e.g. Solaris where readdir() doesn't include type information.
On those platforms we'll still stat() - see D51918.

The result is significantly faster (stat() can be slow).
My motivation: this may allow us to improve clang IO on large TUs with long
include search paths. Caching readdir() results may allow us to skip many stat()
and open() operations on nonexistent files.

Reviewers: bkramer

Subscribers: fedor.sergeev, cfe-commits

Differential Revision: https://reviews.llvm.org/D51921

llvm-svn: 342232

1 files changed, 4 insertions, 4 deletions

diff --git a/clang/lib/Driver/ToolChains/Gnu.cpp b/clang/lib/Driver/ToolChains/Gnu.cpp
index 89119308490..fda02b50a27 100644
--- a/clang/lib/Driver/ToolChains/Gnu.cpp
+++ b/clang/lib/Driver/ToolChains/Gnu.cpp
@@ -1764,7 +1764,7 @@ void Generic_GCC::GCCInstallationDetector::AddDefaultGCCPrefixes(
     std::error_code EC;
     for (vfs::directory_iterator LI = D.getVFS().dir_begin(PrefixDir, EC), LE;
          !EC && LI != LE; LI = LI.increment(EC)) {
-      StringRef VersionText = llvm::sys::path::filename(LI->getName());
+      StringRef VersionText = llvm::sys::path::filename(LI->path());
       GCCVersion CandidateVersion = GCCVersion::Parse(VersionText);
 
       // Filter out obviously bad entries.
@@ -2209,17 +2209,17 @@ void Generic_GCC::GCCInstallationDetector::ScanLibDirForGCCTriple(
              LI = D.getVFS().dir_begin(LibDir + "/" + LibSuffix, EC),
              LE;
          !EC && LI != LE; LI = LI.increment(EC)) {
-      StringRef VersionText = llvm::sys::path::filename(LI->getName());
+      StringRef VersionText = llvm::sys::path::filename(LI->path());
       GCCVersion CandidateVersion = GCCVersion::Parse(VersionText);
       if (CandidateVersion.Major != -1) // Filter obviously bad entries.
-        if (!CandidateGCCInstallPaths.insert(LI->getName()).second)
+        if (!CandidateGCCInstallPaths.insert(LI->path()).second)
           continue; // Saw this path before; no need to look at it again.
       if (CandidateVersion.isOlderThan(4, 1, 1))
         continue;
       if (CandidateVersion <= Version)
         continue;
 
-      if (!ScanGCCForMultilibs(TargetTriple, Args, LI->getName(),
+      if (!ScanGCCForMultilibs(TargetTriple, Args, LI->path(),
                                NeedsBiarchSuffix))
         continue;