Add a comment to explain how the decision to pass feature "+long-calls" is made.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@241568 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index 4aa4bf146410a3334598b12961074be9e8ebb22e..058fdf574da713593410299b49c1e9276325c669 100644 (file)
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -708,6 +708,9 @@ static void getARMTargetFeatures(const Driver &D, const llvm::Triple &Triple,
     Features.insert(Features.begin(), "+v8.1a");
   }
 
+  // Look for the last occurrence of -mlong-calls or -mno-long-calls. If
+  // neither options are specified, see if we are compiling for kernel/kext and
+  // decide whether to pass "+long-calls" based on the OS and its version.
   if (Arg *A = Args.getLastArg(options::OPT_mlong_calls,
                                options::OPT_mno_long_calls)) {
     if (A->getOption().matches(options::OPT_mlong_calls))