From 2626ede61bd9240905ff52a28f864ae1576746b1 Mon Sep 17 00:00:00 2001
From: Don Hinton <hintonda@gmail.com>
Date: Fri, 3 May 2019 18:56:25 +0000
Subject: [PATCH] [CommandLine] Enable Grouping for short options by default. 
 Part 4 of 5

Summary:
This change enables `cl::Grouping` for short options --
options with names of a single character.  This is consistent with GNU
getopt behavior.

Reviewers: rnk, MaskRay

Reviewed By: MaskRay

Subscribers: thopre, cfe-commits, MaskRay, rupprecht, hiraditya, llvm-commits

Tags: #llvm, #clang

Differential Revision: https://reviews.llvm.org/D61270

llvm-svn: 359917
---
 include/llvm/Support/CommandLine.h  | 6 +++++-
 lib/Support/CommandLine.cpp         | 2 ++
 test/tools/llvm-readobj/merged.test | 2 +-
 3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/include/llvm/Support/CommandLine.h b/include/llvm/Support/CommandLine.h
index 7951128a48a..74f5de6621e 100644
--- a/include/llvm/Support/CommandLine.h
+++ b/include/llvm/Support/CommandLine.h
@@ -1200,7 +1200,11 @@ template <> struct applicator<FormattingFlags> {
 };
 
 template <> struct applicator<MiscFlags> {
-  static void opt(MiscFlags MF, Option &O) { O.setMiscFlag(MF); }
+  static void opt(MiscFlags MF, Option &O) {
+    assert((MF != Grouping || O.ArgStr.size() == 1) &&
+           "cl::Grouping can only apply to single charater Options.");
+    O.setMiscFlag(MF);
+  }
 };
 
 // apply method - Apply modifiers to an option in a type safe way.
diff --git a/lib/Support/CommandLine.cpp b/lib/Support/CommandLine.cpp
index 1ca31b69c78..ff53fefefea 100644
--- a/lib/Support/CommandLine.cpp
+++ b/lib/Support/CommandLine.cpp
@@ -421,6 +421,8 @@ void Option::setArgStr(StringRef S) {
     GlobalParser->updateArgStr(this, S);
   assert((S.empty() || S[0] != '-') && "Option can't start with '-");
   ArgStr = S;
+  if (ArgStr.size() == 1)
+    setMiscFlag(Grouping);
 }
 
 void Option::reset() {
diff --git a/test/tools/llvm-readobj/merged.test b/test/tools/llvm-readobj/merged.test
index 0fcc14f1f95..a6f567cda6c 100644
--- a/test/tools/llvm-readobj/merged.test
+++ b/test/tools/llvm-readobj/merged.test
@@ -10,4 +10,4 @@ RUN: FileCheck %s --input-file %t.merged
 RUN: not llvm-readobj -aeWhSrnudlVgIs %p/Inputs/trivial.obj.elf-i386 2>&1 | FileCheck %s --check-prefix=UNKNOWN
 
 CHECK-NOT: Unknown command line argument
-UNKNOWN:   Unknown command line argument
+UNKNOWN:   for the --section-headers option: may only occur zero or one times!