c-auto-align-backslashesc-auto-align-backslashes is a variable defined in `
cc-vars.el'. Its value is
tDocumentation: *Align automatically inserted line continuation backslashes. When line continuation backslashes are inserted automatically for line breaks in multiline macros, e.g. by M-x c-context-line-break, they are aligned with the other backslashes in the same macro if this flag is set. Otherwise the inserted backslashes are preceded by a single space. You can customize this variable.