Improve functions related to (l)stat-ing

Introduced a Stat class that represents a “struct stat”. The class
replaces the utility functions x_lstat, x_stat, file_size_on_disk and
is_symlink, and it provides an easier to use interface than the macros
associated with stat structs.

1 files changed, 45 insertions, 0 deletions

diff --git a/src/Stat.cpp b/src/Stat.cpp
new file mode 100644
index 00000000..ebb47a09
--- /dev/null
+++ b/src/Stat.cpp
@@ -0,0 +1,45 @@
+// Copyright (C) 2019 Joel Rosdahl and other contributors
+//
+// See doc/AUTHORS.adoc for a complete list of contributors.
+//
+// This program is free software; you can redistribute it and/or modify it
+// under the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 3 of the License, or (at your option)
+// any later version.
+//
+// This program is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+// more details.
+//
+// You should have received a copy of the GNU General Public License along with
+// this program; if not, write to the Free Software Foundation, Inc., 51
+// Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+
+#include "Stat.hpp"
+
+#include "ccache.hpp"
+
+#include "third_party/fmt/core.h"
+
+Stat::Stat(StatFunction stat_function,
+           const std::string& path,
+           Stat::OnError on_error)
+{
+  int result = stat_function(path.c_str(), &m_stat);
+  if (result == 0) {
+    m_errno = 0;
+  } else {
+    m_errno = errno;
+    if (on_error == OnError::throw_error) {
+      throw Error(fmt::format("failed to stat {}: {}", path, strerror(errno)));
+    }
+    if (on_error == OnError::log) {
+      cc_log("Failed to stat %s: %s", path.c_str(), strerror(errno));
+    }
+
+    // The file is missing, so just zero fill the stat structure. This will
+    // make e.g. the is_*() methods return false and mtime() will be 0, etc.
+    memset(&m_stat, '\0', sizeof(m_stat));
+  }
+}