From c40345368252e600c43281438c4ca7ce5aa92d56 Mon Sep 17 00:00:00 2001
From: Ilya Biryukov <ibiryukov@google.com>
Date: Fri, 27 Sep 2019 09:24:58 +0000
Subject: [PATCH] [clang-format] Reference qualifiers in member templates
 causing extra indentation

The following code

```
struct f {
  template <class T>
  void bar() && noexcept {}
};
```

will be formatted to the following with LLVM style, and
`AlwaysBreakTemplateDeclarations: Yes`

```
struct f {
  template <class T>
      void bar() && noexcept {}
};
```

The indentation of the `void bar()` line is wrong.

Patch by Andreas Wass (AndWass)!

Differential Revision: https://reviews.llvm.org/D68072

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@373056 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Format/TokenAnnotator.cpp   | 16 +++++++++++----
 unittests/Format/FormatTest.cpp | 35 +++++++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+), 4 deletions(-)

diff --git a/lib/Format/TokenAnnotator.cpp b/lib/Format/TokenAnnotator.cpp
index e584eec368..918d5d3588 100644
--- a/lib/Format/TokenAnnotator.cpp
+++ b/lib/Format/TokenAnnotator.cpp
@@ -65,7 +65,7 @@ public:
   AnnotatingParser(const FormatStyle &Style, AnnotatedLine &Line,
                    const AdditionalKeywords &Keywords)
       : Style(Style), Line(Line), CurrentToken(Line.First), AutoFound(false),
-        Keywords(Keywords) {
+        TrailingReturnFound(false), Keywords(Keywords) {
     Contexts.push_back(Context(tok::unknown, 1, /*IsExpression=*/false));
     resetTokenMetadata(CurrentToken);
   }
@@ -1389,7 +1389,10 @@ private:
     } else if (Current.is(tok::arrow) && AutoFound && Line.MustBeDeclaration &&
                Current.NestingLevel == 0) {
       Current.Type = TT_TrailingReturnArrow;
-    } else if (Current.isOneOf(tok::star, tok::amp, tok::ampamp)) {
+      TrailingReturnFound = true;
+    } else if (Current.is(tok::star) ||
+               (Current.isOneOf(tok::amp, tok::ampamp) &&
+                (!Line.MightBeFunctionDecl || TrailingReturnFound))) {
       Current.Type = determineStarAmpUsage(Current,
                                            Contexts.back().CanBeExpression &&
                                                Contexts.back().IsExpression,
@@ -1412,6 +1415,8 @@ private:
         Current.Type = TT_ConditionalExpr;
       }
     } else if (Current.isBinaryOperator() &&
+               !(Line.MightBeFunctionDecl &&
+                 Current.isOneOf(tok::amp, tok::ampamp)) &&
                (!Current.Previous || Current.Previous->isNot(tok::l_square)) &&
                (!Current.is(tok::greater) &&
                 Style.Language != FormatStyle::LK_TextProto)) {
@@ -1486,10 +1491,12 @@ private:
       // colon after this, this is the only place which annotates the identifier
       // as a selector.)
       Current.Type = TT_SelectorName;
-    } else if (Current.isOneOf(tok::identifier, tok::kw_const) &&
+    } else if (Current.isOneOf(tok::identifier, tok::kw_const, tok::amp,
+                               tok::ampamp) &&
                Current.Previous &&
                !Current.Previous->isOneOf(tok::equal, tok::at) &&
-               Line.MightBeFunctionDecl && Contexts.size() == 1) {
+               Line.MightBeFunctionDecl && !TrailingReturnFound &&
+               Contexts.size() == 1) {
       // Line.MightBeFunctionDecl can only be true after the parentheses of a
       // function declaration have been found.
       Current.Type = TT_TrailingAnnotation;
@@ -1767,6 +1774,7 @@ private:
   AnnotatedLine &Line;
   FormatToken *CurrentToken;
   bool AutoFound;
+  bool TrailingReturnFound;
   const AdditionalKeywords &Keywords;
 
   // Set of "<" tokens that do not open a template parameter list. If parseAngle
diff --git a/unittests/Format/FormatTest.cpp b/unittests/Format/FormatTest.cpp
index 581d15672b..ecb3dddfdf 100644
--- a/unittests/Format/FormatTest.cpp
+++ b/unittests/Format/FormatTest.cpp
@@ -14373,6 +14373,41 @@ TEST_F(FormatTest, AmbersandInLamda) {
   verifyFormat("auto lambda = [&a = a]() { a = 2; };", AlignStyle);
 }
 
+TEST_F(FormatTest, RefQualifiedTemplateMember) {
+  FormatStyle AlignStyle = getLLVMStyle();
+  AlignStyle.AlwaysBreakTemplateDeclarations = FormatStyle::BTDS_Yes;
+
+  verifyFormat("struct f {\n"
+               "  template <class T>\n"
+               "  int &foo() & noexcept {}\n"
+               "};",
+               AlignStyle);
+
+  verifyFormat("struct f {\n"
+               "  template <class T>\n"
+               "  int &foo() && noexcept {}\n"
+               "};",
+               AlignStyle);
+
+  verifyFormat("struct f {\n"
+               "  template <class T>\n"
+               "  int &foo() const & noexcept {}\n"
+               "};",
+               AlignStyle);
+
+  verifyFormat("struct f {\n"
+               "  template <class T>\n"
+               "  int &foo() const & noexcept {}\n"
+               "};",
+               AlignStyle);
+
+  verifyFormat("struct f {\n"
+               "  template <class T>\n"
+               "  auto foo() && noexcept -> int & {}\n"
+               "};",
+               AlignStyle);
+}
+
 } // end namespace
 } // end namespace format
 } // end namespace clang
-- 
2.40.0