Fix crash in clang.

This happened during a recent refactor.  toStringRefArray() returns
a vector<StringRef>, which was being implicitly converted to an
ArrayRef<StringRef>, and then the vector was immediately being
destroyed, so the ArrayRef<> was losing its backing storage.
Fix this by making sure the vector gets permanent storage.

llvm-svn: 336219

1 files changed, 3 insertions, 1 deletions

diff --git a/clang/lib/Driver/Job.cpp b/clang/lib/Driver/Job.cpp
index 74af597ad36..bd1a9bd8e3e 100644
--- a/clang/lib/Driver/Job.cpp
+++ b/clang/lib/Driver/Job.cpp
@@ -318,10 +318,12 @@ int Command::Execute(ArrayRef<llvm::Optional<StringRef>> Redirects,
   SmallVector<const char*, 128> Argv;
 
   Optional<ArrayRef<StringRef>> Env;
+  std::vector<StringRef> ArgvVectorStorage;
   if (!Environment.empty()) {
     assert(Environment.back() == nullptr &&
            "Environment vector should be null-terminated by now");
-    Env = llvm::toStringRefArray(Environment.data());
+    ArgvVectorStorage = llvm::toStringRefArray(Environment.data());
+    Env = makeArrayRef(ArgvVectorStorage);
   }
 
   if (ResponseFile == nullptr) {