4 files changed, 44 insertions, 0 deletions

diff --git a/clang/include/clang/Format/Format.h b/clang/include/clang/Format/Format.h
index d03b8796feb..ab3c1aa3328 100644
--- a/clang/include/clang/Format/Format.h
+++ b/clang/include/clang/Format/Format.h
@@ -110,6 +110,9 @@ struct FormatStyle {
   /// declaration.
   bool AlwaysBreakTemplateDeclarations;
 
+  /// \brief If \c true, always break before multiline string literals.
+  bool AlwaysBreakBeforeMultilineStrings;
+
   /// \brief If true, \c IndentWidth consecutive spaces will be replaced with
   /// tab characters.
   bool UseTab;
@@ -144,6 +147,8 @@ struct FormatStyle {
                R.AllowShortIfStatementsOnASingleLine &&
            AlwaysBreakTemplateDeclarations ==
                R.AlwaysBreakTemplateDeclarations &&
+           AlwaysBreakBeforeMultilineStrings ==
+               R.AlwaysBreakBeforeMultilineStrings &&
            BinPackParameters == R.BinPackParameters &&
            BreakBeforeBraces == R.BreakBeforeBraces &&
            ColumnLimit == R.ColumnLimit &&
diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp
index ef871389fb6..a4b5f4197d4 100644
--- a/clang/lib/Format/Format.cpp
+++ b/clang/lib/Format/Format.cpp
@@ -87,6 +87,8 @@ template <> struct MappingTraits<clang::format::FormatStyle> {
                    Style.AllowShortLoopsOnASingleLine);
     IO.mapOptional("AlwaysBreakTemplateDeclarations",
                    Style.AlwaysBreakTemplateDeclarations);
+    IO.mapOptional("AlwaysBreakBeforeMultilineStrings",
+                   Style.AlwaysBreakBeforeMultilineStrings);
     IO.mapOptional("BinPackParameters", Style.BinPackParameters);
     IO.mapOptional("ColumnLimit", Style.ColumnLimit);
     IO.mapOptional("ConstructorInitializerAllOnOneLineOrOnePerLine",
@@ -127,6 +129,7 @@ FormatStyle getLLVMStyle() {
   LLVMStyle.AllowShortIfStatementsOnASingleLine = false;
   LLVMStyle.AllowShortLoopsOnASingleLine = false;
   LLVMStyle.AlwaysBreakTemplateDeclarations = false;
+  LLVMStyle.AlwaysBreakBeforeMultilineStrings = false;
   LLVMStyle.BinPackParameters = true;
   LLVMStyle.ColumnLimit = 80;
   LLVMStyle.ConstructorInitializerAllOnOneLineOrOnePerLine = false;
@@ -157,6 +160,7 @@ FormatStyle getGoogleStyle() {
   GoogleStyle.AllowShortIfStatementsOnASingleLine = true;
   GoogleStyle.AllowShortLoopsOnASingleLine = true;
   GoogleStyle.AlwaysBreakTemplateDeclarations = true;
+  GoogleStyle.AlwaysBreakBeforeMultilineStrings = true;
   GoogleStyle.BinPackParameters = true;
   GoogleStyle.ColumnLimit = 80;
   GoogleStyle.ConstructorInitializerAllOnOneLineOrOnePerLine = true;
diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index 04f1c7f8a39..806c805208b 100644
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -936,6 +936,13 @@ void TokenAnnotator::calculateFormattingInformation(AnnotatedLine &Line) {
     } else if (Current->Previous->ClosesTemplateDeclaration &&
                Style.AlwaysBreakTemplateDeclarations) {
       Current->MustBreakBefore = true;
+    } else if (Style.AlwaysBreakBeforeMultilineStrings &&
+               Current->is(tok::string_literal) &&
+               Current->Previous->isNot(tok::lessless) &&
+               Current->Previous->Type != TT_InlineASMColon &&
+               Current->getNextNoneComment() &&
+               Current->getNextNoneComment()->is(tok::string_literal)) {
+      Current->MustBreakBefore = true;
     } else {
       Current->MustBreakBefore = false;
     }
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 324f797e6da..c1fdab7cfca 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -2878,6 +2878,34 @@ TEST_F(FormatTest, AlignsStringLiterals) {
                "  \"jkl\");");
 }
 
+TEST_F(FormatTest, AlwaysBreakBeforeMultilineStrings) {
+  FormatStyle NoBreak = getLLVMStyle();
+  NoBreak.AlwaysBreakBeforeMultilineStrings = false;
+  FormatStyle Break = getLLVMStyle();
+  Break.AlwaysBreakBeforeMultilineStrings = true;
+  EXPECT_EQ("aaaa = \"bbbb\"\n"
+            "       \"cccc\";",
+            format("aaaa=\"bbbb\" \"cccc\";", NoBreak));
+  EXPECT_EQ("aaaa =\n"
+            "    \"bbbb\"\n"
+            "    \"cccc\";",
+            format("aaaa=\"bbbb\" \"cccc\";", Break));
+  EXPECT_EQ("aaaa(\"bbbb\"\n"
+            "     \"cccc\");",
+            format("aaaa(\"bbbb\" \"cccc\");", NoBreak));
+  EXPECT_EQ("aaaa(\n"
+            "    \"bbbb\"\n"
+            "    \"cccc\");",
+            format("aaaa(\"bbbb\" \"cccc\");", Break));
+  EXPECT_EQ("aaaa(qqq, \"bbbb\"\n"
+            "          \"cccc\");",
+            format("aaaa(qqq, \"bbbb\" \"cccc\");", NoBreak));
+  EXPECT_EQ("aaaa(qqq,\n"
+            "     \"bbbb\"\n"
+            "     \"cccc\");",
+            format("aaaa(qqq, \"bbbb\" \"cccc\");", Break));
+}
+
 TEST_F(FormatTest, AlignsPipes) {
   verifyFormat(
       "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\n"