[clang-format] Fix breaking enum braces when combined with export (#189128)

This fixes #186684.

Also fix (not) breaking variables declared on the same line as the
closing brace.

And adapt whitesmith to that changes.

clang/lib/Format/Format.cpp

@@ -4115,10 +4115,14 @@ reformat(const FormatStyle &Style, StringRef Code,
   expandPresetsBraceWrapping(Expanded);
   expandPresetsSpaceBeforeParens(Expanded);
   expandPresetsSpacesInParens(Expanded);
+
+  // These are handled by separate passes.
   Expanded.InsertBraces = false;
   Expanded.RemoveBracesLLVM = false;
   Expanded.RemoveParentheses = FormatStyle::RPS_Leave;
   Expanded.RemoveSemicolon = false;
+
+  // Make some sanity adjustments.
   switch (Expanded.RequiresClausePosition) {
   case FormatStyle::RCPS_SingleLine:
   case FormatStyle::RCPS_WithPreceding:
@@ -4127,6 +4131,8 @@ reformat(const FormatStyle &Style, StringRef Code,
   default:
     break;
   }
+  if (Expanded.BraceWrapping.AfterEnum)
+    Expanded.AllowShortEnumsOnASingleLine = false;
 
   if (Expanded.DisableFormat)
     return {tooling::Replacements(), 0};

clang/lib/Format/TokenAnnotator.cpp

@@ -6045,7 +6045,8 @@ bool TokenAnnotator::mustBreakBefore(AnnotatedLine &Line,
 
     if (Style.BraceWrapping.AfterEnum) {
       if (Line.startsWith(tok::kw_enum) ||
-          Line.startsWith(tok::kw_typedef, tok::kw_enum)) {
+          Line.startsWith(tok::kw_typedef, tok::kw_enum) ||
+          Line.startsWith(tok::kw_export, tok::kw_enum)) {
         return true;
       }
       // Ensure BraceWrapping for `public enum A {`.

clang/lib/Format/UnwrappedLineParser.cpp

@@ -3875,26 +3875,40 @@ bool UnwrappedLineParser::parseEnum() {
     return true;
   }
 
+  const bool ManageWhitesmithsBraces =
+      Style.BreakBeforeBraces == FormatStyle::BS_Whitesmiths;
+
   if (!Style.AllowShortEnumsOnASingleLine &&
       ShouldBreakBeforeBrace(Style, InitialToken,
                              Tokens->peekNextToken()->is(tok::r_brace))) {
     addUnwrappedLine();
+
+    // If we're in Whitesmiths mode, indent the brace if we're not indenting
+    // the whole block.
+    if (ManageWhitesmithsBraces)
+      ++Line->Level;
   }
   // Parse enum body.
   nextToken();
   if (!Style.AllowShortEnumsOnASingleLine) {
     addUnwrappedLine();
-    Line->Level += 1;
+    if (!ManageWhitesmithsBraces)
+      ++Line->Level;
   }
+  const auto OpeningLineIndex = CurrentLines->empty()
+                                    ? UnwrappedLine::kInvalidIndex
+                                    : CurrentLines->size() - 1;
   bool HasError = !parseBracedList(/*IsAngleBracket=*/false, /*IsEnum=*/true);
-  if (!Style.AllowShortEnumsOnASingleLine)
-    Line->Level -= 1;
+  if (!Style.AllowShortEnumsOnASingleLine && !ManageWhitesmithsBraces)
+    --Line->Level;
   if (HasError) {
     if (FormatTok->is(tok::semi))
       nextToken();
     addUnwrappedLine();
   }
   setPreviousRBraceType(TT_EnumRBrace);
+  if (ManageWhitesmithsBraces)
+    Line->MatchingOpeningBlockLineIndex = OpeningLineIndex;
   return true;
 
   // There is no addUnwrappedLine() here so that we fall through to parsing a

clang/unittests/Format/FormatTest.cpp

@@ -2885,6 +2885,15 @@ TEST_F(FormatTest, ShortEnums) {
                "  C\n"
                "} ShortEnum1, ShortEnum2;",
                Style);
+
+  Style.AllowShortEnumsOnASingleLine = true;
+  verifyFormat("export enum\n"
+               "{\n"
+               "  A,\n"
+               "  B,\n"
+               "  C\n"
+               "} ShortEnum1, ShortEnum2;",
+               Style);
 }
 
 TEST_F(FormatTest, ShortCompoundRequirement) {
@@ -22146,7 +22155,8 @@ TEST_F(FormatTest, WhitesmithsBraceBreaking) {
                "  {\n"
                "  Y = 0,\n"
                "  Z = 1\n"
-               "  };",
+               "  };\n"
+               "int i;",
                WhitesmithsBraceStyle);
 
   verifyFormat("@interface BSApplicationController ()\n"