Configure/disfigure src_root saving/removing support; fsdir{} injection

We can now build out-of-tree.

1 files changed, 14 insertions, 6 deletions

diff --git a/build/filesystem b/build/filesystem
index c96e669..8617dd4 100644
--- a/build/filesystem
+++ b/build/filesystem
@@ -23,13 +23,21 @@ namespace build
   bool
   file_exists (const path&);
 
-
-  // Note that you should probably use the default mode 0777 and let
-  // the umask mechanism adjust it to the user's preferences. Errors
-  // are reported by throwing std::system_error.
+  // Try to create a directory unless it already exists. If you expect
+  // the directory to exist and performance is important, then you
+  // should first call dir_exists() above since that's what this
+  // implementation will do to make sure the path is actually a
+  // directory.
+  //
+  // You should also probably use the default mode 0777 and let the
+  // umask mechanism adjust it to the user's preferences.
   //
-  void
-  mkdir (const path&, mode_t = 0777);
+  // Errors are reported by throwing std::system_error.
+  //
+  enum class mkdir_status {success, already_exists};
+
+  mkdir_status
+  try_mkdir (const path&, mode_t = 0777);
 
   // Try to remove the directory returning not_exist if it does not
   // exist and not_empty if it is not empty. All other errors are