Convenience/safety fix for llvm::sys::Execute(And|No)Wait

Summary:
Change the type of the Redirects parameter of llvm::sys::ExecuteAndWait,
ExecuteNoWait and other APIs that wrap them from `const StringRef **` to
`ArrayRef<Optional<StringRef>>`, which is safer and simplifies the use of these
APIs (no more local StringRef variables just to get a pointer to).

Corresponding clang changes will be posted as a separate patch.

Reviewers: bkramer

Reviewed By: bkramer

Subscribers: vsk, llvm-commits

Differential Revision: https://reviews.llvm.org/D37563

llvm-svn: 313155

1 files changed, 2 insertions, 2 deletions

diff --git a/llvm/lib/Support/GraphWriter.cpp b/llvm/lib/Support/GraphWriter.cpp
index e04bd8bb3b9..fd7fab08278 100644
--- a/llvm/lib/Support/GraphWriter.cpp
+++ b/llvm/lib/Support/GraphWriter.cpp
@@ -96,7 +96,7 @@ static bool ExecGraphViewer(StringRef ExecPath, std::vector<const char *> &args,
                             std::string &ErrMsg) {
   assert(args.back() == nullptr);
   if (wait) {
-    if (sys::ExecuteAndWait(ExecPath, args.data(), nullptr, nullptr, 0, 0,
+    if (sys::ExecuteAndWait(ExecPath, args.data(), nullptr, {}, 0, 0,
                             &ErrMsg)) {
       errs() << "Error: " << ErrMsg << "\n";
       return true;
@@ -104,7 +104,7 @@ static bool ExecGraphViewer(StringRef ExecPath, std::vector<const char *> &args,
     sys::fs::remove(Filename);
     errs() << " done. \n";
   } else {
-    sys::ExecuteNoWait(ExecPath, args.data(), nullptr, nullptr, 0, &ErrMsg);
+    sys::ExecuteNoWait(ExecPath, args.data(), nullptr, {}, 0, &ErrMsg);
     errs() << "Remember to erase graph file: " << Filename << "\n";
   }
   return false;