r332434 - clang-format: tweak formatting of variable initialization blocks

[Francois Ferrand via cfe-commits]

Author: typz
Date: Wed May 16 01:03:52 2018
New Revision: 332434

URL: http://llvm.org/viewvc/llvm-project?rev=332434&view=rev
Log:
clang-format: tweak formatting of variable initialization blocks

Summary:
This patch changes the behavior of PenaltyBreakBeforeFirstCallParameter
so that is does not apply after a brace, when Cpp11BracedListStyle is
false.

This way, variable initialization is wrapped more like an initializer
than like a function call, which is more consistent with user
expectations for this braced list style.

With PenaltyBreakBeforeFirstCallParameter=200, this gives the following
code: (with Cpp11BracedListStyle=false)

Before :

  const std::unordered_map<std::string, int> Something::MyHashTable =
      { { "aaaaaaaaaaaaaaaaaaaaa", 0 },
        { "bbbbbbbbbbbbbbbbbbbbb", 1 },
        { "ccccccccccccccccccccc", 2 } };

After :

  const std::unordered_set<std::string> Something::MyUnorderedSet = {
    { "aaaaaaaaaaaaaaaaaaaaa", 0 },
    { "bbbbbbbbbbbbbbbbbbbbb", 1 },
    { "ccccccccccccccccccccc", 2 }
  };

Reviewers: krasimir, djasper, klimek

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D43290

Modified:
    cfe/trunk/lib/Format/TokenAnnotator.cpp
    cfe/trunk/unittests/Format/FormatTest.cpp

Modified: cfe/trunk/lib/Format/TokenAnnotator.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Format/TokenAnnotator.cpp?rev=332434&r1=332433&r2=332434&view=diff
==============================================================================
--- cfe/trunk/lib/Format/TokenAnnotator.cpp (original)
+++ cfe/trunk/lib/Format/TokenAnnotator.cpp Wed May 16 01:03:52 2018
@@ -2311,6 +2311,8 @@ unsigned TokenAnnotator::splitPenalty(co
   if (Left.opensScope()) {
     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;
   }
@@ -3048,6 +3050,9 @@ bool TokenAnnotator::canBreakBefore(cons
   if (Left.is(tok::equal) && !Right.isOneOf(tok::kw_default, tok::kw_delete) &&
       Line.Type == LT_VirtualFunctionDecl && Left.NestingLevel == 0)
     return false;
+  if (Left.is(tok::equal) && Right.is(tok::l_brace) &&
+      !Style.Cpp11BracedListStyle)
+    return false;
   if (Left.is(tok::l_paren) && Left.is(TT_AttributeParen))
     return false;
   if (Left.is(tok::l_paren) && Left.Previous &&

Modified: cfe/trunk/unittests/Format/FormatTest.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/unittests/Format/FormatTest.cpp?rev=332434&r1=332433&r2=332434&view=diff
==============================================================================
--- cfe/trunk/unittests/Format/FormatTest.cpp (original)
+++ cfe/trunk/unittests/Format/FormatTest.cpp Wed May 16 01:03:52 2018
@@ -6708,6 +6708,15 @@ TEST_F(FormatTest, LayoutCxx11BraceIniti
                "};");
   verifyFormat("#define A {a, a},");
 
+  // Avoid breaking between equal sign and opening brace
+  FormatStyle AvoidBreakingFirstArgument = getLLVMStyle();
+  AvoidBreakingFirstArgument.PenaltyBreakBeforeFirstCallParameter = 200;
+  verifyFormat("const std::unordered_map<std::string, int> MyHashTable =\n"
+               "    {{\"aaaaaaaaaaaaaaaaaaaaa\", 0},\n"
+               "     {\"bbbbbbbbbbbbbbbbbbbbb\", 1},\n"
+               "     {\"ccccccccccccccccccccc\", 2}};",
+               AvoidBreakingFirstArgument);
+
   // Binpacking only if there is no trailing comma
   verifyFormat("const Aaaaaa aaaaa = {aaaaaaaaaa, bbbbbbbbbb,\n"
                "                      cccccccccc, dddddddddd};",
@@ -6864,6 +6873,21 @@ TEST_F(FormatTest, LayoutCxx11BraceIniti
   verifyFormat("vector<int> foo = { ::SomeGlobalFunction() };", ExtraSpaces);
   verifyFormat("const struct A a = { .a = 1, .b = 2 };", ExtraSpaces);
   verifyFormat("const struct A a = { [0] = 1, [1] = 2 };", ExtraSpaces);
+
+  // Avoid breaking between initializer/equal sign and opening brace
+  ExtraSpaces.PenaltyBreakBeforeFirstCallParameter = 200;
+  verifyFormat("const std::unordered_map<std::string, int> MyHashTable = {\n"
+               "  { \"aaaaaaaaaaaaaaaaaaaaa\", 0 },\n"
+               "  { \"bbbbbbbbbbbbbbbbbbbbb\", 1 },\n"
+               "  { \"ccccccccccccccccccccc\", 2 }\n"
+               "};",
+               ExtraSpaces);
+  verifyFormat("const std::unordered_map<std::string, int> MyHashTable{\n"
+               "  { \"aaaaaaaaaaaaaaaaaaaaa\", 0 },\n"
+               "  { \"bbbbbbbbbbbbbbbbbbbbb\", 1 },\n"
+               "  { \"ccccccccccccccccccccc\", 2 }\n"
+               "};",
+               ExtraSpaces);
 }
 
 TEST_F(FormatTest, FormatsBracedListsInColumnLayout) {