[clang-format] New format param ObjCBinPackProtocolList

Summary:
This is an alternative approach to D42014 after some
investigation by stephanemoore@ and myself.

Previously, the format parameter `BinPackParameters` controlled both
C function parameter list bin-packing and Objective-C protocol conformance
list bin-packing.

We found in the Google style, some teams were changing
`BinPackParameters` from its default (`true`) to `false` so they could
lay out Objective-C protocol conformance list items one-per-line
instead of bin-packing them into as few lines as possible.

To allow teams to use one-per-line Objective-C protocol lists without
changing bin-packing for other areas like C function parameter lists,
this diff introduces a new LibFormat parameter
`ObjCBinPackProtocolList` to control the behavior just for ObjC
protocol conformance lists.

The new parameter is an enum which defaults to `Auto` to keep the
previous behavior (delegating to `BinPackParameters`).

Depends On D42649

Test Plan: New tests added. make -j12 FormatTests && ./tools/clang/unittests/Format/FormatTests

Reviewers: jolesiak, stephanemoore, djasper

Reviewed By: stephanemoore

Subscribers: Wizard, hokein, cfe-commits, klimek

Differential Revision: https://reviews.llvm.org/D42650

llvm-svn: 324131

1 files changed, 15 insertions, 2 deletions

diff --git a/clang/unittests/Format/FormatTestObjC.cpp b/clang/unittests/Format/FormatTestObjC.cpp
index 23e90663717..d9805859f66 100644
--- a/clang/unittests/Format/FormatTestObjC.cpp
+++ b/clang/unittests/Format/FormatTestObjC.cpp
@@ -281,8 +281,7 @@ TEST_F(FormatTestObjC, FormatObjCInterface) {
                "    ccccccccccccc, ccccccccccccc,\n"
                "    ccccccccccccc, ccccccccccccc> {\n"
                "}");
-
-  Style.BinPackParameters = false;
+  Style.ObjCBinPackProtocolList = FormatStyle::BPS_Never;
   verifyFormat("@interface ddddddddddddd () <\n"
                "    ddddddddddddd,\n"
                "    ddddddddddddd,\n"
@@ -290,6 +289,20 @@ TEST_F(FormatTestObjC, FormatObjCInterface) {
                "    ddddddddddddd> {\n"
                "}");
 
+  Style.BinPackParameters = false;
+  Style.ObjCBinPackProtocolList = FormatStyle::BPS_Auto;
+  verifyFormat("@interface eeeeeeeeeeeee () <\n"
+               "    eeeeeeeeeeeee,\n"
+               "    eeeeeeeeeeeee,\n"
+               "    eeeeeeeeeeeee,\n"
+               "    eeeeeeeeeeeee> {\n"
+               "}");
+  Style.ObjCBinPackProtocolList = FormatStyle::BPS_Always;
+  verifyFormat("@interface fffffffffffff () <\n"
+               "    fffffffffffff, fffffffffffff,\n"
+               "    fffffffffffff, fffffffffffff> {\n"
+               "}");
+
   Style = getGoogleStyle(FormatStyle::LK_ObjC);
   verifyFormat("@interface Foo : NSObject <NSSomeDelegate> {\n"
                " @public\n"