[clang][cli] Store LangStandard::Kind in LangOptions

The `LangStandard::Kind` parsed from command line arguments is used to set up some `LangOption` defaults, but isn't stored anywhere.

To be able to generate `-std=` (in future patch), we need `CompilerInvocation` to not forget it.

This patch demonstrates another use-case: using `LangStd` to set up defaults of marshalled options.

Reviewed By: dexonsmith

Differential Revision: https://reviews.llvm.org/D95342

2 files changed, 2 insertions, 4 deletions

diff --git a/clang/lib/Basic/LangOptions.cpp b/clang/lib/Basic/LangOptions.cpp
index c08670c..ed275ad 100644
--- a/clang/lib/Basic/LangOptions.cpp
+++ b/clang/lib/Basic/LangOptions.cpp
@@ -14,7 +14,7 @@
 
 using namespace clang;
 
-LangOptions::LangOptions() {
+LangOptions::LangOptions() : LangStd(LangStandard::lang_unspecified) {
 #define LANGOPT(Name, Bits, Default, Description) Name = Default;
 #define ENUM_LANGOPT(Name, Type, Bits, Default, Description) set##Name(Default);
 #include "clang/Basic/LangOptions.def"
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 3656410..84269b3 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -1971,6 +1971,7 @@ void CompilerInvocation::setLangDefaults(LangOptions &Opts, InputKind IK,
   }
 
   const LangStandard &Std = LangStandard::getLangStandardForKind(LangStd);
+  Opts.LangStd = LangStd;
   Opts.LineComment = Std.hasLineComments();
   Opts.C99 = Std.isC99();
   Opts.C11 = Std.isC11();
@@ -1982,7 +1983,6 @@ void CompilerInvocation::setLangDefaults(LangOptions &Opts, InputKind IK,
   Opts.CPlusPlus17 = Std.isCPlusPlus17();
   Opts.CPlusPlus20 = Std.isCPlusPlus20();
   Opts.CPlusPlus2b = Std.isCPlusPlus2b();
-  Opts.Digraphs = Std.hasDigraphs();
   Opts.GNUMode = Std.isGNUMode();
   Opts.GNUInline = !Opts.C99 && !Opts.CPlusPlus;
   Opts.GNUCVersion = 0;
@@ -2262,8 +2262,6 @@ void CompilerInvocation::ParseLangArgs(LangOptions &Opts, ArgList &Args,
   Opts.GNUKeywords = Args.hasFlag(OPT_fgnu_keywords, OPT_fno_gnu_keywords,
                                   Opts.GNUKeywords);
 
-  Opts.Digraphs = Args.hasFlag(OPT_fdigraphs, OPT_fno_digraphs, Opts.Digraphs);
-
   if (Args.hasArg(OPT_fno_operator_names))
     Opts.CXXOperatorNames = 0;