clang-format: Understand __attribute__s preceding parameter lists.

Before:
  ReturnType __attribute__((unused))
      function(int i);

After:
  ReturnType __attribute__((unused))
  function(int i);

This fixes llvm.org/PR18632.

llvm-svn: 200337

clang/lib/Format/ContinuationIndenter.cpp

@@ -384,7 +384,8 @@ unsigned ContinuationIndenter::addTokenOnNewLine(LineState &State,
   } else if (Previous.is(tok::comma) && State.Stack.back().VariablePos != 0) {
     State.Column = State.Stack.back().VariablePos;
   } else if ((PreviousNonComment &&
-              PreviousNonComment->ClosesTemplateDeclaration) ||
+              (PreviousNonComment->ClosesTemplateDeclaration ||
+               PreviousNonComment->Type == TT_AttributeParen)) ||
              ((Current.Type == TT_StartOfName ||
                Current.is(tok::kw_operator)) &&
               State.ParenLevel == 0 &&

clang/lib/Format/FormatToken.h

@@ -27,6 +27,7 @@ namespace format {
 enum TokenType {
   TT_ArrayInitializerLSquare,
   TT_ArraySubscriptLSquare,
+  TT_AttributeParen,
   TT_BinaryOperator,
   TT_BitFieldColon,
   TT_BlockComment,

clang/lib/Format/TokenAnnotator.cpp

@@ -109,6 +109,8 @@ private:
     } else if (AfterCaret) {
       // This is the parameter list of an ObjC block.
       Contexts.back().IsExpression = false;
+    } else if (Left->Previous && Left->Previous->is(tok::kw___attribute)) {
+      Left->Type = TT_AttributeParen;
     }
 
     if (StartsObjCMethodExpr) {
@@ -159,6 +161,9 @@ private:
           }
         }
 
+        if (Left->Type == TT_AttributeParen)
+          CurrentToken->Type = TT_AttributeParen;
+
         if (!HasMultipleLines)
           Left->PackingKind = PPK_Inconclusive;
         else if (HasMultipleParametersOnALine)
@@ -1332,9 +1337,7 @@ bool TokenAnnotator::spaceRequiredBetween(const AnnotatedLine &Line,
   if (Left.is(tok::colon))
     return Left.Type != TT_ObjCMethodExpr;
   if (Right.is(tok::l_paren)) {
-    if (Left.is(tok::r_paren) && Left.MatchingParen &&
-        Left.MatchingParen->Previous &&
-        Left.MatchingParen->Previous->is(tok::kw___attribute))
+    if (Left.is(tok::r_paren) && Left.Type == TT_AttributeParen)
       return true;
     return Line.Type == LT_ObjCDecl ||
            Left.isOneOf(tok::kw_return, tok::kw_new, tok::kw_delete,
@@ -1519,14 +1522,12 @@ bool TokenAnnotator::canBreakBefore(const AnnotatedLine &Line,
     return false;
   if (Left.is(tok::equal) && Line.Type == LT_VirtualFunctionDecl)
     return false;
-  if (Left.Previous) {
-    if (Left.is(tok::l_paren) && Right.is(tok::l_paren) &&
-        Left.Previous->is(tok::kw___attribute))
-      return false;
-    if (Left.is(tok::l_paren) && (Left.Previous->Type == TT_BinaryOperator ||
-                                  Left.Previous->Type == TT_CastRParen))
-      return false;
-  }
+  if (Left.is(tok::l_paren) && Left.Type == TT_AttributeParen)
+    return false;
+  if (Left.is(tok::l_paren) && Left.Previous &&
+      (Left.Previous->Type == TT_BinaryOperator ||
+       Left.Previous->Type == TT_CastRParen))
+    return false;
   if (Right.Type == TT_ImplicitStringLiteral)
     return false;
 
@@ -1570,7 +1571,7 @@ bool TokenAnnotator::canBreakBefore(const AnnotatedLine &Line,
          Right.isOneOf(tok::lessless, tok::arrow, tok::period, tok::colon,
                        tok::l_square, tok::at) ||
          (Left.is(tok::r_paren) &&
-          Right.isOneOf(tok::identifier, tok::kw_const, tok::kw___attribute)) ||
+          Right.isOneOf(tok::identifier, tok::kw_const)) ||
          (Left.is(tok::l_paren) && !Right.is(tok::r_paren));
 }
 

clang/unittests/Format/FormatTest.cpp

@@ -4394,6 +4394,8 @@ TEST_F(FormatTest, UnderstandsUsesOfStarAndAmp) {
 
 TEST_F(FormatTest, UnderstandsAttributes) {
   verifyFormat("SomeType s __attribute__((unused)) (InitValue);");
+  verifyFormat("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa __attribute__((unused))\n"
+               "aaaaaaaaaaaaaaaaaaaaaaa(int i);");
 }
 
 TEST_F(FormatTest, UnderstandsEllipsis) {