[clang-format] Don't wrap before attributes in parameter lists (#132519)

Fix #132240

Author: owenca

clang/lib/Format/TokenAnnotator.cpp

@@ -4078,6 +4078,7 @@ void TokenAnnotator::calculateFormattingInformation(AnnotatedLine &Line) const {
   }
 
   bool InFunctionDecl = Line.MightBeFunctionDecl;
+  bool InParameterList = false;
   for (auto *Current = First->Next; Current; Current = Current->Next) {
     const FormatToken *Prev = Current->Previous;
     if (Current->is(TT_LineComment)) {
@@ -4132,6 +4133,19 @@ void TokenAnnotator::calculateFormattingInformation(AnnotatedLine &Line) const {
 
     Current->CanBreakBefore =
         Current->MustBreakBefore || canBreakBefore(Line, *Current);
+
+    if (Current->is(TT_FunctionDeclarationLParen)) {
+      InParameterList = true;
+    } else if (Current->is(tok::r_paren)) {
+      const auto *LParen = Current->MatchingParen;
+      if (LParen && LParen->is(TT_FunctionDeclarationLParen))
+        InParameterList = false;
+    } else if (InParameterList &&
+               Current->endsSequence(TT_AttributeMacro,
+                                     TT_PointerOrReference)) {
+      Current->CanBreakBefore = false;
+    }
+
     unsigned ChildSize = 0;
     if (Prev->Children.size() == 1) {
       FormatToken &LastOfChild = *Prev->Children[0]->Last;

clang/unittests/Format/FormatTest.cpp

@@ -12640,6 +12640,12 @@ TEST_F(FormatTest, UnderstandsAttributes) {
                AfterType);
 
   FormatStyle CustomAttrs = getLLVMStyle();
+  CustomAttrs.AttributeMacros.push_back("my_attr_name");
+  verifyFormat("void MyGoodOldFunction(\n"
+               "    void *const long_enough = nullptr,\n"
+               "    void *my_attr_name even_longeeeeeeeeeeeeeeeeer = nullptr);",
+               CustomAttrs);
+
   CustomAttrs.AttributeMacros.push_back("__unused");
   CustomAttrs.AttributeMacros.push_back("__attr1");
   CustomAttrs.AttributeMacros.push_back("__attr2");