[clang-format] Revert breaking stream operators to previous default (#89016)

Reverts commit d68826d, which changes the previous default behavior
of always breaking before a stream insertion operator `<<` if both
operands are string literals.

Also reverts the related commits 27f5479 and bf05be5.

See the discussion in #88483.

Author: owenca

clang/lib/Format/TokenAnnotator.cpp

@@ -5595,12 +5595,8 @@ bool TokenAnnotator::mustBreakBefore(const AnnotatedLine &Line,
     return true;
   if (Left.IsUnterminatedLiteral)
     return true;
-  // FIXME: Breaking after newlines seems useful in general. Turn this into an
-  // option and recognize more cases like endl etc, and break independent of
-  // what comes after operator lessless.
-  if (Right.is(tok::lessless) && Right.Next &&
-      Right.Next->is(tok::string_literal) && Left.is(tok::string_literal) &&
-      Left.TokenText.ends_with("\\n\"")) {
+  if (Right.is(tok::lessless) && Right.Next && Left.is(tok::string_literal) &&
+      Right.Next->is(tok::string_literal)) {
     return true;
   }
   if (Right.is(TT_RequiresClause)) {

clang/unittests/Format/FormatTest.cpp

@@ -27339,12 +27339,6 @@ TEST_F(FormatTest, PPDirectivesAndCommentsInBracedInit) {
                getLLVMStyleWithColumns(30));
 }
 
-TEST_F(FormatTest, StreamOutputOperator) {
-  verifyFormat("std::cout << \"foo\" << \"bar\" << baz;");
-  verifyFormat("std::cout << \"foo\\n\"\n"
-               "          << \"bar\";");
-}
-
 TEST_F(FormatTest, BreakAdjacentStringLiterals) {
   constexpr StringRef Code{
       "return \"Code\" \"\\0\\52\\26\\55\\55\\0\" \"x013\" \"\\02\\xBA\";"};
@@ -27359,6 +27353,7 @@ TEST_F(FormatTest, BreakAdjacentStringLiterals) {
   Style.BreakAdjacentStringLiterals = false;
   verifyFormat(Code, Style);
 }
+
 } // namespace
 } // namespace test
 } // namespace format

clang/unittests/Format/TokenAnnotatorTest.cpp

@@ -2841,15 +2841,6 @@ TEST_F(TokenAnnotatorTest, BraceKind) {
   EXPECT_BRACE_KIND(Tokens[16], BK_BracedInit);
 }
 
-TEST_F(TokenAnnotatorTest, StreamOperator) {
-  auto Tokens = annotate("\"foo\\n\" << aux << \"foo\\n\" << \"foo\";");
-  ASSERT_EQ(Tokens.size(), 9u) << Tokens;
-  EXPECT_FALSE(Tokens[1]->MustBreakBefore);
-  EXPECT_FALSE(Tokens[3]->MustBreakBefore);
-  // Only break between string literals if the former ends with \n.
-  EXPECT_TRUE(Tokens[5]->MustBreakBefore);
-}
-
 TEST_F(TokenAnnotatorTest, UnderstandsElaboratedTypeSpecifier) {
   auto Tokens = annotate("auto foo() -> enum En {}");
   ASSERT_EQ(Tokens.size(), 10u) << Tokens;

polly/lib/Analysis/DependenceInfo.cpp

@@ -951,8 +951,8 @@ class DependenceInfoPrinterLegacyPass final : public ScopPass {
   bool runOnScop(Scop &S) override {
     DependenceInfo &P = getAnalysis<DependenceInfo>();
 
-    OS << "Printing analysis '" << P.getPassName() << "' for " << "region: '"
-       << S.getRegion().getNameStr() << "' in function '"
+    OS << "Printing analysis '" << P.getPassName() << "' for "
+       << "region: '" << S.getRegion().getNameStr() << "' in function '"
        << S.getFunction().getName() << "':\n";
     P.printScop(OS, S);
 

polly/lib/Analysis/ScopBuilder.cpp

@@ -2715,9 +2715,10 @@ void ScopBuilder::addUserContext() {
     if (NameContext != NameUserContext) {
       std::string SpaceStr = stringFromIslObj(Space, "null");
       errs() << "Error: the name of dimension " << i
-             << " provided in -polly-context " << "is '" << NameUserContext
-             << "', but the name in the computed " << "context is '"
-             << NameContext << "'. Due to this name mismatch, "
+             << " provided in -polly-context "
+             << "is '" << NameUserContext << "', but the name in the computed "
+             << "context is '" << NameContext
+             << "'. Due to this name mismatch, "
              << "the -polly-context option is ignored. Please provide "
              << "the context in the parameter space: " << SpaceStr << ".\n";
       return;