clang-format: Don't use column layout in lists that have separating

comments. At some point, we might to want to a layout with a different
number of columns instead, but at the moment, this causes more
confusion than it's worth.

llvm-svn: 237427

2 files changed, 17 insertions, 9 deletions

diff --git a/clang/lib/Format/FormatToken.cpp b/clang/lib/Format/FormatToken.cpp
index 2f0b32971b6..42036666b0b 100644
--- a/clang/lib/Format/FormatToken.cpp
+++ b/clang/lib/Format/FormatToken.cpp
@@ -153,10 +153,13 @@ void CommaSeparatedList::precomputeFormattingInfos(const FormatToken *Token) {
   // trailing comments which are otherwise ignored for column alignment.
   SmallVector<unsigned, 8> EndOfLineItemLength;
 
+  bool HasSeparatingComment = false;
   for (unsigned i = 0, e = Commas.size() + 1; i != e; ++i) {
     // Skip comments on their own line.
-    while (ItemBegin->HasUnescapedNewline && ItemBegin->isTrailingComment())
+    while (ItemBegin->HasUnescapedNewline && ItemBegin->isTrailingComment()) {
       ItemBegin = ItemBegin->Next;
+      HasSeparatingComment = i > 0;
+    }
 
     MustBreakBeforeItem.push_back(ItemBegin->MustBreakBefore);
     if (ItemBegin->is(tok::l_brace))
@@ -193,10 +196,9 @@ void CommaSeparatedList::precomputeFormattingInfos(const FormatToken *Token) {
     ItemBegin = ItemEnd->Next;
   }
 
-  // If this doesn't have a nested list, we require at least 6 elements in order
-  // create a column layout. If it has a nested list, column layout ensures one
-  // list element per line.
-  if (Commas.size() < 5 || Token->NestingLevel != 0)
+  // Don't use column layout for nested lists, lists with few elements and in
+  // presence of separating comments.
+  if (Token->NestingLevel != 0 || Commas.size() < 5 || HasSeparatingComment)
     return;
 
   // We can never place more than ColumnLimit / 3 items in a row (because of the
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 9661919f517..ecc1a7e1342 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -6313,11 +6313,9 @@ TEST_F(FormatTest, FormatsBracedListsInColumnLayout) {
                "                 1, 22, 333, 4444, 55555, 666666, 7777777,\n"
                "                 1, 22, 333, 4444, 55555, 666666, 7777777,\n"
                "                 1, 22, 333, 4444, 55555, 666666, 7777777};");
-  verifyFormat("vector<int> x = {1, 22, 333, 4444, 55555, 666666, 7777777,\n"
-               "                 // line comment\n"
+  verifyFormat("vector<int> x = {1, 22, 333, 4444, 55555, 666666, 7777777, //\n"
                "                 1, 22, 333, 4444, 55555, 666666, 7777777,\n"
-               "                 1, 22, 333, 4444, 55555,\n"
-               "                 // line comment\n"
+               "                 1, 22, 333, 4444, 55555, //\n"
                "                 1, 22, 333, 4444, 55555, 666666, 7777777,\n"
                "                 1, 22, 333, 4444, 55555, 666666, 7777777};");
   verifyFormat(
@@ -6331,6 +6329,14 @@ TEST_F(FormatTest, FormatsBracedListsInColumnLayout) {
   verifyFormat("static const uint16_t CallerSavedRegs64Bittttt[] = {\n"
                "    X86::RAX, X86::RDX, X86::RCX, X86::RSI, X86::RDI,\n"
                "    X86::R8,  X86::R9,  X86::R10, X86::R11, 0};");
+  verifyFormat("static const uint16_t CallerSavedRegs64Bittttt[] = {\n"
+               "    X86::RAX, X86::RDX, X86::RCX, X86::RSI, X86::RDI,\n"
+               "    // Separating comment.\n"
+               "    X86::R8, X86::R9, X86::R10, X86::R11, 0};");
+  verifyFormat("static const uint16_t CallerSavedRegs64Bittttt[] = {\n"
+               "    // Leading comment\n"
+               "    X86::RAX, X86::RDX, X86::RCX, X86::RSI, X86::RDI,\n"
+               "    X86::R8,  X86::R9,  X86::R10, X86::R11, 0};");
   verifyFormat("vector<int> x = {1, 1, 1, 1,\n"
                "                 1, 1, 1, 1};",
                getLLVMStyleWithColumns(39));