[Format/ObjC] Avoid breaking between unary operators and operands

[benhamilton]

Summary

Test Plan:

New tests added. Ran tests with:
% ninja FormatTests && ./tools/clang/unittests/Format/FormatTests
Confirmed tests failed before change and passed after change.

[sammccall]

clang/lib/Format/TokenAnnotator.cpp

2427–2428

This looks a little suspicious only because it's so specific.

It seems like you'd *always* want a harsh penalty for breaking between a unary operator and its operand. @klimek does this look right, should we drop the ObcJMethodExpr requirement or is this case handled elsewhere?

[benhamilton]

• Rebase.
• Change to just avoid breaking when the left-hand side is a unary operator

[benhamilton]

clang/lib/Format/TokenAnnotator.cpp

2427–2428

I tried changing it to just if (Left.is(TT_UnaryOperator)) and all the tests passed. I'll go for the gusto and assume this is fine.

[benhamilton]

Any more thoughts on this?

[sammccall]

Yeah, worst case we'll need to roll this back and go with the targeted fix, but I don't see a problem.

clang/lib/Format/TokenAnnotator.cpp

if (Style.AlignAfterOpenBracket == FormatStyle::BAS_DontAlign)
       return 0;
     if (Left.is(tok::l_brace) && !Style.Cpp11BracedListStyle)
       return 19;
     return Left.ParameterCount > 1 ? Style.PenaltyBreakBeforeFirstCallParameter
                                    : 19;
   }
   if (Left.is(TT_JavaAnnotation))
     return 50;
 
+  if (Left.is(TT_UnaryOperator) && Right.is(TT_ObjCMethodExpr))
+    return 60;
   if (Left.isOneOf(tok::plus, tok::comma) && Left.Previous &&
       Left.Previous->isLabelString() &&
       (Left.NextOperator || Left.OperatorIndex != 0))
     return 50;
   if (Right.is(tok::plus) && Left.isLabelString() &&
       (Right.NextOperator || Right.OperatorIndex != 0))
     return 25;
   if (Left.is(tok::comma))

clang/unittests/Format/FormatTestObjC.cpp

TEST_F(FormatTestObjC, FormatObjCMethodExpr) {
   Style.ColumnLimit = 30;
   verifyFormat("fooooooo =\n"
                "    [[obj fooo] aaa:42\n"
                "                aaa:42];");
   verifyFormat("[[[obj foo] bar] aa:42\n"
                "                 bb:42\n"
                "                 cc:42];");
 
+  // Avoid breaking between unary operators and ObjC method expressions.
+  Style.ColumnLimit = 45;
+  verifyFormat("if (a012345678901234567890123 &&\n"
+               "    ![foo bar]) {\n"
+               "}");
+  verifyFormat("if (a012345678901234567890123 &&\n"
+               "    +[foo bar]) {\n"
+               "}");
+  verifyFormat("if (a012345678901234567890123 &&\n"
+               "    -[foo bar]) {\n"
+               "}");
+
   Style.ColumnLimit = 70;
   verifyFormat(
       "void f() {\n"
       "  popup_wdow_.reset([[RenderWidgetPopupWindow alloc]\n"
       "      iniithContentRect:NSMakRet(origin_global.x, origin_global.y,\n"
       "                                 pos.width(), pos.height())\n"
       "                syeMask:NSBorderlessWindowMask\n"
       "                  bking:NSBackingStoreBuffered\n"