This blog is updated daily.
A general description is here.
The ‘Writing R Extensions’ Texinfo source now contains very experimental annotations for more clearly identifying the API status of C entry points. These annotations are used to produce indices for API, experimental API, and embedded API entry points in the rendered versions. This is very preliminary and may be dropped if a better approach emerges.
Also now for Fortran-callable entry points which are part of the API.
‘R CMD INSTALL’ (and hence ‘check’) now by default compile C++ code with ‘-DR_NO_REMAP’. For the time being this can be reverted by setting environment variable‘_R_CXX_USE_NO_REMAP_’ to a false value (but that will be removed in the near future).
`Writing R Extensions' has been revised to describe the remapped entry points, for with the ‘Rf_’ prefix remains optional when used from C code (but is recommended for new C code).
‘R CMD check’ now reports more warnings on long-deprecated/obsolete Fortran features reported by ‘gfortran -Wall’. For hints on how to modernize these, see <https://fortranwiki.org/fortran/show/Modernizing+Old+Fortran>.