In D38061#1484486, @dblaikie wrote:

Seems like the right thing would be for the DWARF code that wants a rendered type name to pass its own printing policy, rather than changing some relatively global one.

(though also I have my doubts about the whole approach - macro expansion can change the line number as well as the column number, so only suppressing column number would be insufficient - and this also reduces the usability for users (because the file/line/column of an anonymous type is a useful debugging aid). Seems to me like this should be opt-in if it's supported at all - though ideally build systems would use -frewrite-includes rather than full preprocessing, and then macros and lines/columns would be preserved, I think)