[Rcpp-devel] Error linking: Undefined reference to...

[Dirk Eddelbuettel]

Hi Bjørn,

Welcome!

On 8 September 2011 at 10:36, Bjørn Skogtrø wrote:
| Hi guys.
| 
| First off, thanks for a nice piece of software.
| 
| Now to the issue at hand:
| 
| I'm trying to compile and link the package obtained using Rcpp.package.skeleton
| (...) (out of the box). I'm running R 2.13.1, with Rcpp 0.9.6 on a Windows XP
| machine. 
| 
| The first problem I ran into was how the package-libs variable PKG_LIBS was
| pasted into the g++ string for compiling:
| 
| g++ -shared -s -static-libgcc -o processes.dll tmp.def rcpp_hello_world.o
| rcpp_module.o C:/Program Files/R/R-2.13.1/library/Rcpp/lib/i386/libRcpp.a -LC:/
| PROGRA~1/R/R-213~1.1/bin/i386 -lR
| g++.exe: C:/Program: No such file or directory
| g++.exe: Files/R/R-2.13.1/library/Rcpp/lib/i386/libRcpp.a: No such file or
| directory
| ERROR: compilation failed for package 'processes'
| * removing 'D:/Documents/Eclipse/processes.Rcheck/processes'
| 
| As you can see, paths with spaces in them is not cool.

Correct. The shell / Makefile quoting gets in the way.

If someone comes with _reliable ways to improve this_ we'd be open for
patches. Until then the recommendation is to not use directories with spaces.

| I resolved this by overriding it in makevars.win by hard-coding it, so my makevars.win looks like

Good idea.
 
| ## Use the R_HOME indirection to support installations of multiple R version
| ## PKG_LIBS = $(shell "${R_HOME}/bin${R_ARCH_BIN}/Rscript.exe" -e
| "Rcpp:::LdFlags()")
| PKG_LIBS = $("C:/PROGRA~1/R/R-2.13.1/library/Rcpp/lib/i386/libRcpp.a")
| 
| Compiling then works fine, and spits out the files rcpp_module.o and
| rcpp_hello_world.o. The problem then is linking, which complains over
| "undefined reference":
| 
| * installing *source* package 'processes' ...
| ** libs
| cygwin warning:
|   MS-DOS style path detected: C:/PROGRA~1/R/R-213~1.1/etc/i386/Makeconf
|   Preferred POSIX equivalent is: /cygdrive/c/PROGRA~1/R/R-213~1.1/etc/i386/
| Makeconf
|   CYGWIN environment variable option "nodosfilewarning" turns off this
| warning.
|   Consult the user's guide for more details about POSIX paths:
|     http://cygwin.com/cygwin-ug-net/using.html#using-pathnames
| g++ -shared -s -static-libgcc -o processes.dll tmp.def rcpp_hello_world.o
| rcpp_module.o -LC:/PROGRA~1/R/R-213~1.1/bin/i386 -lR
| rcpp_hello_world.o:rcpp_hello_world.cpp:(.text+0x66): undefined reference to
| `Rcpp::RObject::setSEXP(SEXPREC*)'
| rcpp_hello_world.o:rcpp_hello_world.cpp:(.text+0x71): undefined reference to
| `void Rcpp::internal::r_init_vector<16>(SEXPREC*)'
| rcpp_hello_world.o:rcpp_hello_world.cpp:(.text+0x148): undefined reference to
| `Rcpp::RObject::setSEXP(SEXPREC*)'
| rcpp_hello_world.o:rcpp_hello_world.cpp:(.text+0x1a7): undefined reference to
| `Rcpp::RObject::setSEXP(SEXPREC*)'
| 
| I'm assuming that these two errors are somewhat related, but can't figure it
| out (the compile processs running R CMD check is a bit intransparent to me). I
| should mention that this exact procedure worked fine until I upgraded from
| 2.13.0 to 2.13.1 yesterday.
| 
| Any clues on what to look at??

Your PKG_LIBS appears to be wrong:

   g++ -shared -s -static-libgcc -o processes.dll tmp.def rcpp_hello_world.o
        rcpp_module.o -LC:/PROGRA~1/R/R-213~1.1/bin/i386 -lR

You need a -L part for a location, as well as -l part giving a library, eg

   g++ -shared -s -static-libgcc -o processes.dll tmp.def rcpp_hello_world.o
        rcpp_module.o -LC:/PROGRA~1/R/R-213~1.1/bin/i386 -lRcpp -lR

where I added -lRcpp.

Hope this helps,  Dirk
 
| Thanks!
| 
| BR,
| Bjørn
| 
| 
| --
| Up, down, turn around
| Please dont let me hit the ground
| Tonight I think Ill walk alone
| Ill find my soul as I go home.
| 
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-- 
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