CommandLine: bail out when options get multiply registered

These errors are strictly unrecoverable and indicate serious issues such as
conflicting option names or an incorrectly linked LLVM distribution.

With this change, the errors actually get detected so tests don't pass
silently.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211260 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Support/CommandLine.cpp

@@ -145,6 +145,7 @@ void OptionCategory::registerCategory() {
 static void GetOptionInfo(SmallVectorImpl<Option*> &PositionalOpts,
                           SmallVectorImpl<Option*> &SinkOpts,
                           StringMap<Option*> &OptionsMap) {
+  bool HadErrors = false;
   SmallVector<const char*, 16> OptionNames;
   Option *CAOpt = nullptr;  // The ConsumeAfter option if it exists.
   for (Option *O = RegisteredOptionList; O; O = O->getNextRegisteredOption()) {
@@ -158,8 +159,9 @@ static void GetOptionInfo(SmallVectorImpl<Option*> &PositionalOpts,
     for (size_t i = 0, e = OptionNames.size(); i != e; ++i) {
       // Add argument to the argument map!
       if (OptionsMap.GetOrCreateValue(OptionNames[i], O).second != O) {
-        errs() << ProgramName << ": CommandLine Error: Argument '"
-             << OptionNames[i] << "' defined more than once!\n";
+        errs() << ProgramName << ": CommandLine Error: Option '"
+               << OptionNames[i] << "' registered more than once!\n";
+        HadErrors = true;
       }
     }
 
@@ -171,8 +173,10 @@ static void GetOptionInfo(SmallVectorImpl<Option*> &PositionalOpts,
     else if (O->getMiscFlags() & cl::Sink) // Remember sink options
       SinkOpts.push_back(O);
     else if (O->getNumOccurrencesFlag() == cl::ConsumeAfter) {
-      if (CAOpt)
+      if (CAOpt) {
         O->error("Cannot specify more than one option with cl::ConsumeAfter!");
+        HadErrors = true;
+      }
       CAOpt = O;
     }
   }
@@ -182,6 +186,12 @@ static void GetOptionInfo(SmallVectorImpl<Option*> &PositionalOpts,
 
   // Make sure that they are in order of registration not backwards.
   std::reverse(PositionalOpts.begin(), PositionalOpts.end());
+
+  // Fail hard if there were errors. These are strictly unrecoverable and
+  // indicate serious issues such as conflicting option names or an incorrectly
+  // linked LLVM distribution.
+  if (HadErrors)
+    report_fatal_error("inconsistency in registered CommandLine options");
 }