[lld] r297677 - Add a comment to say that -build-id=sha1 is a synonym for tree.

[Rui Ueyama via llvm-commits]

Author: ruiu
Date: Mon Mar 13 16:48:38 2017
New Revision: 297677

URL: http://llvm.org/viewvc/llvm-project?rev=297677&view=rev
Log:
Add a comment to say that -build-id=sha1 is a synonym for tree.

Modified:
    lld/trunk/ELF/Driver.cpp

Modified: lld/trunk/ELF/Driver.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Driver.cpp?rev=297677&r1=297676&r2=297677&view=diff
==============================================================================
--- lld/trunk/ELF/Driver.cpp (original)
+++ lld/trunk/ELF/Driver.cpp Mon Mar 13 16:48:38 2017
@@ -631,7 +631,9 @@ void LinkerDriver::readConfigs(opt::Inpu
 
   std::tie(Config->SysvHash, Config->GnuHash) = getHashStyle(Args);
 
-  // Parse --build-id or --build-id=<style>.
+  // Parse --build-id or --build-id=<style>. We handle "tree" as a
+  // synonym for "sha1" because all of our hash functions including
+  // -build-id=sha1 are tree hashes for performance reasons.
   if (Args.hasArg(OPT_build_id))
     Config->BuildId = BuildIdKind::Fast;
   if (auto *Arg = Args.getLastArg(OPT_build_id_eq)) {