clang-format: Add new style option AlignConsecutiveMacros

This option behaves similarly to AlignConsecutiveDeclarations and
AlignConsecutiveAssignments, aligning the assignment of C/C++
preprocessor macros on consecutive lines.

I've worked in many projects (embedded, mostly) where header files full
of large, well-aligned "#define" blocks are a common pattern. We
normally avoid using clang-format on these files, since it ruins any
existing alignment in said blocks. This style option will align "simple"
PP macros (no parameters) and PP macros with parameter lists on
consecutive lines.

Related Bugzilla entry (thanks mcuddie):
https://llvm.org/bugs/show_bug.cgi?id=20637

Patch by Nick Renieris (VelocityRa)!

Differential Revision: https://reviews.llvm.org/D28462

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@364938 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 13 insertions, 0 deletions

diff --git a/include/clang/Format/Format.h b/include/clang/Format/Format.h
index c5034db71a..6388e4fc17 100644
--- a/include/clang/Format/Format.h
+++ b/include/clang/Format/Format.h
@@ -79,6 +79,19 @@ struct FormatStyle {
   /// brackets.
   BracketAlignmentStyle AlignAfterOpenBracket;
 
+  /// \brief If ``true``, aligns consecutive C/C++ preprocessor macros.
+  ///
+  /// This will align C/C++ preprocessor macros of consecutive lines.
+  /// Will result in formattings like
+  /// \code
+  ///   #define SHORT_NAME       42
+  ///   #define LONGER_NAME      0x007f
+  ///   #define EVEN_LONGER_NAME (2)
+  ///   #define foo(x)           (x * x)
+  ///   #define bar(y, z)        (y + z)
+  /// \endcode
+  bool AlignConsecutiveMacros;
+
   /// If ``true``, aligns consecutive assignments.
   ///
   /// This will align the assignment operators of consecutive lines. This