[Reproducers] Copy over access/modification time in the FileCollector.

Copy over access and modification time for the files included in the
reproducer. This is needed to pass tests that check the integrity of
object files based on their time stamp.

llvm-svn: 364457

lldb/source/Utility/FileCollector.cpp

@@ -11,6 +11,7 @@
 #include "llvm/ADT/SmallString.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Path.h"
+#include "llvm/Support/Process.h"
 
 using namespace lldb_private;
 using namespace llvm;
@@ -104,6 +105,27 @@ void FileCollector::AddFileImpl(StringRef src_path) {
   AddFileToMapping(virtual_path, dst_path);
 }
 
+/// Set the access and modification time for the given file from the given
+/// status object.
+static std::error_code
+CopyAccessAndModificationTime(StringRef filename,
+                              const sys::fs::file_status &stat) {
+  int fd;
+
+  if (auto ec =
+          sys::fs::openFileForWrite(filename, fd, sys::fs::CD_OpenExisting))
+    return ec;
+
+  if (auto ec = sys::fs::setLastAccessAndModificationTime(
+          fd, stat.getLastAccessedTime(), stat.getLastModificationTime()))
+    return ec;
+
+  if (auto ec = sys::Process::SafelyCloseFileDescriptor(fd))
+    return ec;
+
+  return {};
+}
+
 std::error_code FileCollector::CopyFiles(bool stop_on_error) {
   for (auto &entry : m_vfs_writer.getMappings()) {
     // Create directory tree.
@@ -127,6 +149,15 @@ std::error_code FileCollector::CopyFiles(bool stop_on_error) {
           return ec;
       }
     }
+
+    // Copy over modification time.
+    sys::fs::file_status stat;
+    if (std::error_code ec = sys::fs::status(entry.VPath, stat)) {
+      if (stop_on_error)
+        return ec;
+      continue;
+    }
+    CopyAccessAndModificationTime(entry.RPath, stat);
   }
   return {};
 }