Support: Have directory_iterator::status() return FindFirstFileEx/FindNextFile results on Windows.

This allows clients to avoid an unnecessary fs::status() call on each
directory entry. Because the information returned by FindFirstFileEx
is a subset of the information returned by a regular status() call,
I needed to extract a base class from file_status that contains only
that information.

On my machine, this reduces the time required to enumerate a ThinLTO
cache directory containing 520k files from almost 4 minutes to less
than 2 seconds.

Differential Revision: https://reviews.llvm.org/D38716

llvm-svn: 315378

2 files changed, 12 insertions, 9 deletions

diff --git a/clang-tools-extra/modularize/CoverageChecker.cpp b/clang-tools-extra/modularize/CoverageChecker.cpp
index 510d062..3687872 100644
--- a/clang-tools-extra/modularize/CoverageChecker.cpp
+++ b/clang-tools-extra/modularize/CoverageChecker.cpp
@@ -242,14 +242,15 @@ bool CoverageChecker::collectUmbrellaHeaders(StringRef UmbrellaDirName) {
     Directory = ".";
   // Walk the directory.
   std::error_code EC;
-  sys::fs::file_status Status;
   for (sys::fs::directory_iterator I(Directory.str(), EC), E; I != E;
     I.increment(EC)) {
     if (EC)
       return false;
     std::string File(I->path());
-    I->status(Status);
-    sys::fs::file_type Type = Status.type();
+    llvm::ErrorOr<sys::fs::basic_file_status> Status = I->status();
+    if (!Status)
+      return false;
+    sys::fs::file_type Type = Status->type();
     // If the file is a directory, ignore the name and recurse.
     if (Type == sys::fs::file_type::directory_file) {
       if (!collectUmbrellaHeaders(File))
@@ -363,7 +364,6 @@ bool CoverageChecker::collectFileSystemHeaders(StringRef IncludePath) {
 
   // Recursively walk the directory tree.
   std::error_code EC;
-  sys::fs::file_status Status;
   int Count = 0;
   for (sys::fs::recursive_directory_iterator I(Directory.str(), EC), E; I != E;
     I.increment(EC)) {
@@ -371,8 +371,10 @@ bool CoverageChecker::collectFileSystemHeaders(StringRef IncludePath) {
       return false;
     //std::string file(I->path());
     StringRef file(I->path());
-    I->status(Status);
-    sys::fs::file_type type = Status.type();
+    llvm::ErrorOr<sys::fs::basic_file_status> Status = I->status();
+    if (!Status)
+      return false;
+    sys::fs::file_type type = Status->type();
     // If the file is a directory, ignore the name (but still recurses).
     if (type == sys::fs::file_type::directory_file)
       continue;
diff --git a/clang-tools-extra/modularize/ModularizeUtilities.cpp b/clang-tools-extra/modularize/ModularizeUtilities.cpp
index 874742d..85768d5 100644
--- a/clang-tools-extra/modularize/ModularizeUtilities.cpp
+++ b/clang-tools-extra/modularize/ModularizeUtilities.cpp
@@ -399,14 +399,15 @@ bool ModularizeUtilities::collectUmbrellaHeaders(StringRef UmbrellaDirName,
   SmallString<256> Directory(UmbrellaDirName);
   // Walk the directory.
   std::error_code EC;
-  llvm::sys::fs::file_status Status;
   for (llvm::sys::fs::directory_iterator I(Directory.str(), EC), E; I != E;
     I.increment(EC)) {
     if (EC)
       return false;
     std::string File(I->path());
-    I->status(Status);
-    llvm::sys::fs::file_type Type = Status.type();
+    llvm::ErrorOr<llvm::sys::fs::basic_file_status> Status = I->status();
+    if (!Status)
+      return false;
+    llvm::sys::fs::file_type Type = Status->type();
     // If the file is a directory, ignore the name and recurse.
     if (Type == llvm::sys::fs::file_type::directory_file) {
       if (!collectUmbrellaHeaders(File, Dependents))