This task adds configuration and migration script, to evaluate moving to clang-format.

Usage

To run the migration:

make format

Or to only operate on certain paths:

make format PATHS="intern/cycles source/creator"

Migration TODO's

Migration scripts.

• Check clang-format version is >= 6.0.
• make format for windows make.bat
  
  Although windows users will likely use MSVC's built-in clang-format.
• make format could only format modified files
  
  Better default for developers) perhaps make format-all runs on all files.

Pre Migration cleanup.

• Some header guards are not the first pre-processor lines in the file causing them not to be detected, causing all preprocessor arguments to be indented. rB5681631109852d1037cddafd60f39552f8ba3bbf
  
  Search for #\s+define\s+.*_H__\b after formatting to see issues.

• Tabs in string literals should be replaced with \t or converted to spaces.
  
  This way we can avoid tabs in C/C++ source, expanding all tabs to spaces when migrating.

• source/blender/nodes/NOD_static_types.h gives unusable indentation (disable formatting for this file? or add ; after each DefNode). rBb389bb5ef8aedb65313ac61188246461bc03d22a
• blender/python/generic/bgl.c macro use causes a lot of indentation. rB0373ff5e9c30f01717678b5265df3501891ce5e5

Clang-format TODO's

Where clang-format doesn't produce acceptable output.

• intern/clog/CLG_log.h header guard detection fails, caused by __func__ workaround, needs investigation, seereport https://bugs.llvm.org/show_bug.cgi?id=40288 rB302970b7a5e9b6510f58d786501542e162140d2e

Notes

• the clang-format script will eventually be moved into source/tools/utils.