Support: Fix option handling when using cl::Required with aliasopt

Until now, attempting to create an alias of a required option would
complain if the user supplied the alias, because the required option
didn't have a value. Similarly, if you said the alias was required,
then using the base option would complain that the alias wasn't
supplied. Lastly, if you put required on both, *neither* option would
work.

By changning alias to overload addOccurrence and setting cl::Required
on the original option, we can get this to behave in a more useful
way. I've also added a test and updated a user that was getting this
wrong.

llvm-svn: 212986

1 files changed, 19 insertions, 0 deletions

diff --git a/llvm/unittests/Support/CommandLineTest.cpp b/llvm/unittests/Support/CommandLineTest.cpp
index b2d71ab..e4a1b67 100644
--- a/llvm/unittests/Support/CommandLineTest.cpp
+++ b/llvm/unittests/Support/CommandLineTest.cpp
@@ -212,4 +212,23 @@ TEST(CommandLineTest, AliasesWithArguments) {
   }
 }
 
+void testAliasRequired(int argc, const char *const *argv) {
+  StackOption<std::string> Option("option", cl::Required);
+  cl::alias Alias("o", llvm::cl::aliasopt(Option));
+
+  cl::ParseCommandLineOptions(argc, argv);
+  EXPECT_EQ("x", Option);
+  EXPECT_EQ(1, Option.getNumOccurrences());
+
+  Alias.removeArgument();
+}
+
+TEST(CommandLineTest, AliasRequired) {
+  const char *opts1[] = { "-tool", "-option=x" };
+  const char *opts2[] = { "-tool", "-o", "x" };
+  testAliasRequired(array_lengthof(opts1), opts1);
+  testAliasRequired(array_lengthof(opts2), opts2);
+}
+
+
 }  // anonymous namespace