add unit test

Author: farzonl

clang/unittests/Frontend/CompilerInvocationTest.cpp

@@ -732,6 +732,26 @@ TEST_F(CommandLineTest, ConditionalParsingIfTrueFlagPresent) {
   ASSERT_THAT(GeneratedArgs, Contains(StrEq("-sycl-std=2017")));
 }
 
+TEST_F(CommandLineTest, ConditionalParsingIfHLSLFlagPresent) {
+  const char *Args[] = {"-xhlsl"};
+
+  CompilerInvocation::CreateFromArgs(Invocation, Args, *Diags);
+
+  ASSERT_EQ(Invocation.getLangOpts().MaxMatrixDimension, 4u);
+
+  Invocation.generateCC1CommandLine(GeneratedArgs, *this);
+}
+
+TEST_F(CommandLineTest, ConditionalParsingIfHLSLFlagNotPresent) {
+  const char *Args[] = {""};
+
+  CompilerInvocation::CreateFromArgs(Invocation, Args, *Diags);
+
+  ASSERT_EQ(Invocation.getLangOpts().MaxMatrixDimension, 1048575u);
+
+  Invocation.generateCC1CommandLine(GeneratedArgs, *this);
+}
+
 // Wide integer option.
 
 TEST_F(CommandLineTest, WideIntegerHighValue) {