[clang-format] fix conflict between FormatStyle::BWACS_MultiLine and BeforeCatch/BeforeElse

Summary:
Found a bug introduced with BraceWrappingFlags AfterControlStatement MultiLine. This feature conflicts with the existing BeforeCatch and BeforeElse flags.

For example, our team uses BeforeElse.

if (foo ||
    bar) {
  doSomething();
}
else {
  doSomethingElse();
}

If we enable MultiLine (which we'd really love to do) we expect it to work like this:

if (foo ||
    bar)
{
  doSomething();
}
else {
  doSomethingElse();
}

What we actually get is:

if (foo ||
    bar)
{
  doSomething();
}
else
{
  doSomethingElse();
}

Reviewers: MyDeveloperDay, Bouska, mitchell-stellar

Patch by: pastey

Subscribers: Bouska, cfe-commits

Tags: clang

Differential Revision: https://reviews.llvm.org/D71939

1 files changed, 13 insertions, 0 deletions

diff --git a/clang/lib/Format/UnwrappedLineFormatter.cpp b/clang/lib/Format/UnwrappedLineFormatter.cpp
index 8b8d357d9cb..fec85f1174d 100644
--- a/clang/lib/Format/UnwrappedLineFormatter.cpp
+++ b/clang/lib/Format/UnwrappedLineFormatter.cpp
@@ -326,6 +326,19 @@ private:
               FormatStyle::BWACS_Always)
                  ? tryMergeSimpleBlock(I, E, Limit)
                  : 0;
+    } else if (I[1]->First->is(tok::l_brace) &&
+               TheLine->First->isOneOf(tok::kw_else, tok::kw_catch) &&
+               Style.BraceWrapping.AfterControlStatement ==
+                   FormatStyle::BWACS_MultiLine) {
+      // This case if different from the upper BWACS_MultiLine processing
+      // in that a preceding r_brace is not on the same line as else/catch
+      // most likely because of BeforeElse/BeforeCatch set to true.
+      // If the line length doesn't fit ColumnLimit, leave l_brace on the
+      // next line to respect the BWACS_MultiLine.
+      return (Style.ColumnLimit == 0 ||
+              TheLine->Last->TotalLength <= Style.ColumnLimit)
+                 ? 1
+                 : 0;
     }
     // Try to merge either empty or one-line block if is precedeed by control
     // statement token