You generally want the PKG_*
variants in your local file, e.g. ~/.R/Makevars
.
Here is a (shortened, edited) portion of mine:
## for C code
CFLAGS= -O3 -g0 -Wall -pipe -pedantic -std=gnu99
## for C++ code
#CXXFLAGS= -g -O3 -Wall -pipe -Wno-unused -pedantic -std=c++11
CXXFLAGS= -g -O3 -Wall -pipe -Wno-unused -pedantic
## for Fortran code
#FFLAGS=-g -O3 -Wall -pipe
FFLAGS=-O3 -g0 -Wall -pipe
## for Fortran 95 code
#FCFLAGS=-g -O3 -Wall -pipe
FCFLAGS=-O3 -g0 -Wall -pipe
VER=-4.8
CC=ccache gcc$(VER)
CXX=ccache g++$(VER)
SHLIB_CXXLD=g++$(VER)
FC=ccache gfortran
F77=ccache gfortran
MAKE=make -j8
The other (system-global) approach is to create and edit /etc/R/Makeconf.site
(or, when /etc/R/
does not exist, $RHOME/etc/R/Makeconf.site
.