From: Krasimir Georgiev <krasimir@google.com>
Date: Mon, 4 Feb 2019 09:56:16 +0000 (+0000)
Subject: [clang-format] Fix breaking of qualified operator
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=8070ca12f87e66f76db528c107e9d291f4a91498;p=clang

[clang-format] Fix breaking of qualified operator

Summary:
From https://bugs.llvm.org/show_bug.cgi?id=40516
```
$ cat a.cpp
const NamespaceName::VeryLongClassName &NamespaceName::VeryLongClassName::myFunction() {
  // do stuff
}

const NamespaceName::VeryLongClassName &NamespaceName::VeryLongClassName::operator++() {
  // do stuff
}
$ ~/ll/build/opt/bin/clang-format -style=LLVM a.cpp
const NamespaceName::VeryLongClassName &
NamespaceName::VeryLongClassName::myFunction() {
  // do stuff
}

const NamespaceName::VeryLongClassName &NamespaceName::VeryLongClassName::
operator++() {
  // do stuff
}
```
What was happening is that the split penalty before `operator` was being set to
a smaller value by a prior if block. Moved checks around to fix this and added a
regression test.

Reviewers: djasper

Reviewed By: djasper

Tags: #clang

Differential Revision: https://reviews.llvm.org/D57604

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@353033 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Format/TokenAnnotator.cpp b/lib/Format/TokenAnnotator.cpp
index 1c93c8c6cc..45896d86ad 100644
--- a/lib/Format/TokenAnnotator.cpp
+++ b/lib/Format/TokenAnnotator.cpp
@@ -2249,6 +2249,9 @@ unsigned TokenAnnotator::splitPenalty(const AnnotatedLine &Line,
       return 500;
   }
 
+  if (Left.is(tok::coloncolon) ||
+      (Right.is(tok::period) && Style.Language == FormatStyle::LK_Proto))
+    return 500;
   if (Right.isOneOf(TT_StartOfName, TT_FunctionDeclarationName) ||
       Right.is(tok::kw_operator)) {
     if (Line.startsWith(tok::kw_for) && Right.PartOfMultiVariableDeclStmt)
@@ -2267,9 +2270,6 @@ unsigned TokenAnnotator::splitPenalty(const AnnotatedLine &Line,
     return 160;
   if (Left.is(TT_CastRParen))
     return 100;
-  if (Left.is(tok::coloncolon) ||
-      (Right.is(tok::period) && Style.Language == FormatStyle::LK_Proto))
-    return 500;
   if (Left.isOneOf(tok::kw_class, tok::kw_struct))
     return 5000;
   if (Left.is(tok::comment))
diff --git a/unittests/Format/FormatTest.cpp b/unittests/Format/FormatTest.cpp
index 99b2beadc4..2b0ef9a9dd 100644
--- a/unittests/Format/FormatTest.cpp
+++ b/unittests/Format/FormatTest.cpp
@@ -4183,6 +4183,18 @@ TEST_F(FormatTest, BreaksFunctionDeclarations) {
                Style);
 }
 
+TEST_F(FormatTest, DontBreakBeforeQualifiedOperator) {
+  // Regression test for https://bugs.llvm.org/show_bug.cgi?id=40516:
+  // Prefer keeping `::` followed by `operator` together.
+  EXPECT_EQ("const aaaa::bbbbbbb &\n"
+            "ccccccccc::operator++() {\n"
+            "  stuff();\n"
+            "}",
+            format("const aaaa::bbbbbbb\n"
+                   "&ccccccccc::operator++() { stuff(); }",
+                   getLLVMStyleWithColumns(40)));
+}
+
 TEST_F(FormatTest, TrailingReturnType) {
   verifyFormat("auto foo() -> int;\n");
   verifyFormat("struct S {\n"