diff --git a/llvm/include/llvm/Support/CommandLine.h b/llvm/include/llvm/Support/CommandLine.h
--- a/llvm/include/llvm/Support/CommandLine.h
+++ b/llvm/include/llvm/Support/CommandLine.h
@@ -66,7 +66,8 @@
bool ParseCommandLineOptions(int argc, const char *const *argv,
StringRef Overview = "",
raw_ostream *Errs = nullptr,
- const char *EnvVar = nullptr);
+ const char *EnvVar = nullptr,
+ bool LongOptionsUseDoubleDash = false);
//===----------------------------------------------------------------------===//
// ParseEnvironmentOptions - Environment variable option processing alternate
diff --git a/llvm/lib/Support/CommandLine.cpp b/llvm/lib/Support/CommandLine.cpp
--- a/llvm/lib/Support/CommandLine.cpp
+++ b/llvm/lib/Support/CommandLine.cpp
@@ -148,7 +148,8 @@
void ResetAllOptionOccurrences();
bool ParseCommandLineOptions(int argc, const char *const *argv,
- StringRef Overview, raw_ostream *Errs = nullptr);
+ StringRef Overview, raw_ostream *Errs = nullptr,
+ bool LongOptionsUseDoubleDash = false);
void addLiteralOption(Option &Opt, SubCommand *SC, StringRef Name) {
if (Opt.hasArgStr())
@@ -686,8 +687,9 @@
static Option *getOptionPred(StringRef Name, size_t &Length,
bool (*Pred)(const Option *),
const StringMap