[PATCH] D109582: [clang-format] Restrict the special handling for K&R C to C/C++

[Owen Pan via Phabricator via cfe-commits]

owenpan created this revision.
owenpan added reviewers: krasimir, MyDeveloperDay, HazardyKnusperkeks.
owenpan added a project: clang-format.
owenpan requested review of this revision.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.

Commits 58494c856a15 <https://reviews.llvm.org/rG58494c856a15f5b0e886c7baf5d505ac6c05dfe5>, f6bc614546e1 <https://reviews.llvm.org/rGf6bc614546e169bb1b17a29c422ebace038e6c62>, and 0fc27ef19670 <https://reviews.llvm.org/rG0fc27ef19670676689d3317948c81eb171bb25f8> added special handlings for K&R C function definitions and caused some JavaScript regressions which were addressed in https://reviews.llvm.org/D107267 and https://reviews.llvm.org/D108538. This patch could have prevented these known regressions and will fix any unknown ones.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D109582

Files:
  clang/lib/Format/TokenAnnotator.cpp
  clang/unittests/Format/FormatTest.cpp


Index: clang/unittests/Format/FormatTest.cpp
===================================================================
--- clang/unittests/Format/FormatTest.cpp
+++ clang/unittests/Format/FormatTest.cpp
@@ -8277,6 +8277,12 @@
   verifyFormat("int\n"
                "f(a)",
                Style);
+  verifyFormat("bool\n"
+               "f(size_t = 0, bool b = false)\n"
+               "{\n"
+               "  return !b;\n"
+               "}",
+               Style);
 
   // The return breaking style doesn't affect:
   // * function and object definitions with attribute-like macros
Index: clang/lib/Format/TokenAnnotator.cpp
===================================================================
--- clang/lib/Format/TokenAnnotator.cpp
+++ clang/lib/Format/TokenAnnotator.cpp
@@ -2398,7 +2398,7 @@
 
 // This function heuristically determines whether 'Current' starts the name of a
 // function declaration.
-static bool isFunctionDeclarationName(const FormatToken &Current,
+static bool isFunctionDeclarationName(bool IsCpp, const FormatToken &Current,
                                       const AnnotatedLine &Line) {
   auto skipOperatorName = [](const FormatToken *Next) -> const FormatToken * {
     for (; Next; Next = Next->Next) {
@@ -2476,14 +2476,21 @@
   if (Next->MatchingParen->Next &&
       Next->MatchingParen->Next->is(TT_PointerOrReference))
     return true;
-  // Check for K&R C function definitions, e.g.:
+
+  // Check for K&R C function definitions (and C++ function definitions with
+  // unnamed parameters), e.g.:
   //   int f(i)
   //   {
   //     return i + 1;
   //   }
-  if (Next->Next && Next->Next->is(tok::identifier) &&
+  //   bool g(size_t = 0, bool b = false)
+  //   {
+  //     return !b;
+  //   }
+  if (IsCpp && Next->Next && Next->Next->is(tok::identifier) &&
       !Line.endsWith(tok::semi))
     return true;
+
   for (const FormatToken *Tok = Next->Next; Tok && Tok != Next->MatchingParen;
        Tok = Tok->Next) {
     if (Tok->is(TT_TypeDeclarationParen))
@@ -2544,7 +2551,7 @@
     calculateArrayInitializerColumnList(Line);
 
   while (Current) {
-    if (isFunctionDeclarationName(*Current, Line))
+    if (isFunctionDeclarationName(Style.isCpp(), *Current, Line))
       Current->setType(TT_FunctionDeclarationName);
     if (Current->is(TT_LineComment)) {
       if (Current->Previous->is(BK_BracedInit) &&


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