Add file comments to Driver.cpp.

llvm-svn: 293130

1 files changed, 16 insertions, 0 deletions

diff --git a/lld/ELF/Driver.cpp b/lld/ELF/Driver.cpp
index 2b358251610..92370ab1ec3 100644
--- a/lld/ELF/Driver.cpp
+++ b/lld/ELF/Driver.cpp
@@ -6,6 +6,22 @@
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
+//
+// The driver drives the entire linking process. It is responsible for
+// parsing command line options and doing whatever it is instructed to do.
+//
+// One notable thing in the LLD's driver when compared to other linkers is
+// that the LLD's driver is agnostic on the host operating system.
+// Other linkers usually have implicit default values (such as a dynamic
+// linker path or library paths) for each host OS.
+//
+// I don't think implicit default values are useful because they are
+// usually explicitly specified by the compiler driver. They can even
+// be harmful when you are doing cross-linking. Therefore, in LLD, we
+// simply trust the compiler driver to pass all required options to us
+// and don't try to make effort on our side.
+//
+//===----------------------------------------------------------------------===//
 
 #include "Driver.h"
 #include "Config.h"