Fixes issue with Allman BreakBeforeBraces for Objective C @interface (PR19511)

[dinesh.d]

Summary

I am not sure if this is real issue. But if we decide to fix this, we may use this patch.

issue:
libformat has code comment stating that if interface has instance variables, it keeps '{' in
same line ragardless of BreakBeforeBraces setting.

UnwrappedLineParser::parseObjCInterfaceOrImplementation()
{
...
// If instance variables are present, keep the '{' on the first line too.

if (FormatTok->Tok.is(tok::l_brace))
  parseBlock(/*MustBeDeclaration=*/true);

...
}

But for Allman and GNU style of BreakBeforeBraces, we should break before '{'

[klimek]

Looks good (not that I have an idea about objective C, but it seems to make sense).
Do you have commit access or do you need one of us to commit it?

[dinesh.d]

Thanks for review.

I do not have commit access. I need help in committing this.

[dinesh.d]

Submitted (r207849).

I got my commit access yesterday. Thanks for review and support.

lib/Format/UnwrappedLineParser.cpp

     nextToken(); // base class name
   } else if (FormatTok->Tok.is(tok::l_paren))
     // Skip category, if present.
     parseParens();
 
   if (FormatTok->Tok.is(tok::less))
     parseObjCProtocolList();
 
-  // If instance variables are present, keep the '{' on the first line too.
-  if (FormatTok->Tok.is(tok::l_brace))
+  if (FormatTok->Tok.is(tok::l_brace)) {
+    if (Style.BreakBeforeBraces == FormatStyle::BS_Allman ||
+        Style.BreakBeforeBraces == FormatStyle::BS_GNU)
+      addUnwrappedLine();
     parseBlock(/*MustBeDeclaration=*/true);
+  }
 
   // With instance variables, this puts '}' on its own line.  Without instance
   // variables, this ends the @interface line.
   addUnwrappedLine();
 
   parseObjCUntilAtEnd();
 }
 

unittests/Format/FormatTest.cpp

                BreakBeforeBrace);
 
   verifyFormat("enum X\n"
                "{\n"
                "  Y = 0,\n"
                "}\n",
                BreakBeforeBrace);
 
+  verifyFormat("@interface BSApplicationController ()\n"
+               "{\n"
+               "@private\n"
+               "  id _extraIvar;\n"
+               "}\n"
+               "@end\n",
+               BreakBeforeBrace);
+
   BreakBeforeBrace.ColumnLimit = 19;
   verifyFormat("void f() { int i; }", BreakBeforeBrace);
   BreakBeforeBrace.ColumnLimit = 18;
   verifyFormat("void f()\n"
                "{\n"
                "  int i;\n"
                "}",
                BreakBeforeBrace);

                "}\n",
                GNUBraceStyle);
 
   verifyFormat("enum X\n"
                "{\n"
                "  Y = 0,\n"
                "}\n",
                GNUBraceStyle);
+
+  verifyFormat("@interface BSApplicationController ()\n"
+               "{\n"
+               "@private\n"
+               "  id _extraIvar;\n"
+               "}\n"
+               "@end\n",
+               GNUBraceStyle);
 }
 TEST_F(FormatTest, CatchExceptionReferenceBinding) {
   verifyFormat("void f() {\n"
                "  try {\n"
                "  }\n"
                "  catch (const Exception &e) {\n"
                "  }\n"
                "}\n",