MC: Don't assume incoming StringRef's are null terminated.

This can happen when processing command line arguments, which
are often stored as std::string's and later turned into
StringRef's via std::string::data().  Unfortunately this
is not guaranteed to return a null-terminated string
until C++11, causing breakage on platforms that don't do this.

llvm-svn: 192558

1 files changed, 1 insertions, 4 deletions

diff --git a/llvm/lib/MC/SubtargetFeature.cpp b/llvm/lib/MC/SubtargetFeature.cpp
index 68d68fff546..2fb91f2125b 100644
--- a/llvm/lib/MC/SubtargetFeature.cpp
+++ b/llvm/lib/MC/SubtargetFeature.cpp
@@ -121,13 +121,10 @@ void SubtargetFeatures::AddFeature(const StringRef String,
 /// Find KV in array using binary search.
 static const SubtargetFeatureKV *Find(StringRef S, const SubtargetFeatureKV *A,
                                       size_t L) {
-  // Make the lower bound element we're looking for
-  SubtargetFeatureKV KV;
-  KV.Key = S.data();
   // Determine the end of the array
   const SubtargetFeatureKV *Hi = A + L;
   // Binary search the array
-  const SubtargetFeatureKV *F = std::lower_bound(A, Hi, KV);
+  const SubtargetFeatureKV *F = std::lower_bound(A, Hi, S);
   // If not found then return NULL
   if (F == Hi || StringRef(F->Key) != S) return NULL;
   // Return the found array item