R devel - Apr 2026 - Removing declarations for non-API functions

As part of clarifying R's C API for use in packages we are planning to
remove declarations of non-API functions from public header files.
Actual uses leading to symbol references in shared libraries have been
receiving check WARNINGs for some time. But in some cases code may
still contain uses of these functions that cause compiler errors. In
some cases such code is directly in packages; in other cases it is
brought in by linking to other packages.

Using a current R-devel you can set -DNO_LEGACY_NONAPI in Makevars and
try to install your package to check if removal of these non-API
declarations might affect you.

Best,

luke

-- 
Luke Tierney
Ralph E. Wareham Professor of Mathematical Sciences
University of Iowa                  Phone:             319-335-3386
Department of Statistics and        Fax:               319-335-3017
    Actuarial Science
241 Schaeffer Hall                  email:   luke-tierney at uiowa.edu
Iowa City, IA 52242                 WWW:  http://www.stat.uiowa.edu