clang-format: Improve heuristics to detect function declarations/definitions.

Specifically understand ellipses in parameter lists and treat trailing
reference qualifiers and the "{" as signals.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@266599 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Format/TokenAnnotator.cpp b/lib/Format/TokenAnnotator.cpp
index 2f3bb3a8c7b4145af1a291bcec7d06076e9ada07..9c745399434c9a29f8952504bae88edab195bbde 100644 (file)
--- a/lib/Format/TokenAnnotator.cpp
+++ b/lib/Format/TokenAnnotator.cpp
@@ -1553,7 +1553,8 @@ void TokenAnnotator::annotate(AnnotatedLine &Line) {
 
 // This function heuristically determines whether 'Current' starts the name of a
 // function declaration.
-static bool isFunctionDeclarationName(const FormatToken &Current) {
+static bool isFunctionDeclarationName(const FormatToken &Current,
+                                      const AnnotatedLine &Line) {
   auto skipOperatorName = [](const FormatToken* Next) -> const FormatToken* {
     for (; Next; Next = Next->Next) {
       if (Next->is(TT_OverloadedOperatorLParen))
@@ -1573,6 +1574,7 @@ static bool isFunctionDeclarationName(const FormatToken &Current) {
     return nullptr;
   };
 
+  // Find parentheses of parameter list.
   const FormatToken *Next = Current.Next;
   if (Current.is(tok::kw_operator)) {
     if (Current.Previous && Current.Previous->is(tok::coloncolon))
@@ -1602,14 +1604,22 @@ static bool isFunctionDeclarationName(const FormatToken &Current) {
     }
   }
 
-  if (!Next || !Next->is(tok::l_paren))
+  // Check whether parameter list can be long to a function declaration.
+  if (!Next || !Next->is(tok::l_paren) || !Next->MatchingParen)
     return false;
+  // If the lines ends with "{", this is likely an function definition.
+  if (Line.Last->is(tok::l_brace))
+    return true;
   if (Next->Next == Next->MatchingParen)
+    return true; // Empty parentheses.
+  // If there is an &/&& after the r_paren, this is likely a function.
+  if (Next->MatchingParen->Next &&
+      Next->MatchingParen->Next->is(TT_PointerOrReference))
     return true;
   for (const FormatToken *Tok = Next->Next; Tok && Tok != Next->MatchingParen;
        Tok = Tok->Next) {
     if (Tok->is(tok::kw_const) || Tok->isSimpleTypeSpecifier() ||
-        Tok->isOneOf(TT_PointerOrReference, TT_StartOfName))
+        Tok->isOneOf(TT_PointerOrReference, TT_StartOfName, tok::ellipsis))
       return true;
     if (Tok->isOneOf(tok::l_brace, tok::string_literal, TT_ObjCMethodExpr) ||
         Tok->Tok.isLiteral())
@@ -1655,7 +1665,7 @@ void TokenAnnotator::calculateFormattingInformation(AnnotatedLine &Line) {
   FormatToken *Current = Line.First->Next;
   bool InFunctionDecl = Line.MightBeFunctionDecl;
   while (Current) {
-    if (isFunctionDeclarationName(*Current))
+    if (isFunctionDeclarationName(*Current, Line))
       Current->Type = TT_FunctionDeclarationName;
     if (Current->is(TT_LineComment)) {
       if (Current->Previous->BlockKind == BK_BracedInit &&

diff --git a/unittests/Format/FormatTest.cpp b/unittests/Format/FormatTest.cpp
index 1b0e5865b771a471deb7c4ab542942ea76c62319..0a9969a9b70a500eaf464a9110dfa43707850799 100644 (file)
--- a/unittests/Format/FormatTest.cpp
+++ b/unittests/Format/FormatTest.cpp
@@ -5621,6 +5621,10 @@ TEST_F(FormatTest, UnderstandsFunctionRefQualification) {
                AlignLeft);
   verifyFormat("Deleted& operator=(const Deleted&) &;", AlignLeft);
   verifyFormat("SomeType MemberFunction(const Deleted&) &;", AlignLeft);
+  verifyFormat("auto Function(T t) & -> void {}", AlignLeft);
+  verifyFormat("auto Function(T... t) & -> void {}", AlignLeft);
+  verifyFormat("auto Function(T) & -> void {}", AlignLeft);
+  verifyFormat("auto Function(T) & -> void;", AlignLeft);
 
   FormatStyle Spaces = getLLVMStyle();
   Spaces.SpacesInCStyleCastParentheses = true;
@@ -6119,6 +6123,10 @@ TEST_F(FormatTest, BreaksLongDeclarations) {
                "LooooooooooooooooooooooooooooooooooongFunctionDefinition() {}");
   verifyFormat("decltype(LoooooooooooooooooooooooooooooooooooooooongName)\n"
                "LooooooooooooooooooooooooooooooooooongFunctionDefinition() {}");
+  verifyFormat("LoooooooooooooooooooooooooooooooooooooooongReturnType\n"
+               "LooooooooooooooooooooooooooongFunctionDeclaration(T... t);");
+  verifyFormat("LoooooooooooooooooooooooooooooooooooooooongReturnType\n"
+               "LooooooooooooooooooooooooooongFunctionDeclaration(T /*t*/) {}");
   FormatStyle Indented = getLLVMStyle();
   Indented.IndentWrappedFunctionNames = true;
   verifyFormat("LoooooooooooooooooooooooooooooooooooooooongReturnType\n"