Changing CXXFLAGS in R CMD INSTALL for developing R packages

Question

I'm trying to debug a package that I'm developing. I use a makefile for building, checking and installing the packages. The packages is an Rcpp package and so already has a makevars and makevars.win file in it. What I am looking for is a was to have CXXFLAGS changed just for a specific make rule. Then make debug will run R CMD INSTALL with CXXFLAGS= -Wall -pedantic -g -O0" but regular make install will run with CXXFLAGS=-O3 without any debugging info. is there a good way to dynamically change this without having to modify my package, personal or system makevars files?

Answer 1

I don't think so as there is only one CXXFLAGS to go around. But you could reassign again in differnt 'make' vs `make debug' target portions.

You could just keep two versions ~/.R/Makevars.normal amd ~/R/Makevars.debug and use a script to flip a link between them...

For what it is worth. I just edit ~/.R/Makevars and comment/uncomment different lines.

Edit: What about something like this, based on the Makefile you posted:

install: $(PKG_NAME)_$(PKG_VERSION).tar.gz
    CXXFLAGS+="-O3" R CMD INSTALL $(PKG_NAME)_$(PKG_VERSION).tar.gz

debuginstall: $(PKG_NAME)_$(PKG_VERSION).tar.gz
    CXXFLAGS+="-Wall -g -O0" R CMD INSTALL $(PKG_NAME)_$(PKG_VERSION).tar.gz

Edit 2: I just played with this, and it works:

PKG_NAME=digest
PKG_VERSION=0.5.1

install: $(PKG_NAME)_$(PKG_VERSION).tar.gz
    PKG_CFLAGS="-O6" R CMD INSTALL $(PKG_NAME)_$(PKG_VERSION).tar.gz

debuginstall: $(PKG_NAME)_$(PKG_VERSION).tar.gz
    PKG_CFLAGS="-Wall -g -O0" R CMD INSTALL $(PKG_NAME)_$(PKG_VERSION).tar.gz

It still reads my ~/.R/Makevars afterwards so certain vars cannot be set here. But you could just set MYDEBUG=... in your Makefile and then use that inside a definition in ~/.R/Makevars.