I'm currently attempting to make an existing project to link statically to its main dependency in order to reduce size of the resulting output library. The project I'm trying to change is Tesseract OCR that depends on Leptonica image processing library.
At the time being, Leptonica counts 2481 functions but Tesseract uses only 163 of them. In other words, only 6,6% of Leptonica functionality is used in Tesseract but the whole bunch of code (3,5 MB + additional libraries) will be loaded and kept in memory. It's probably not an issue at all for desktop systems. But on mobile devices with limited memory, it's too costly to have several MBs occupied by unused code.
I hope to reduce the overall size of this Tesseract+Leptonica couple using static linking. Both projects utilize autoconfig/automake/libtool build system.
Leptonica's build produces both static and dynamic libraries. Tesseract uses the following line in its configure.ac in order to declare Leptonica dependency:
AC_CHECK_LIB(lept,pixCreate,[],AC_MSG_ERROR([Leptonica library missing]))
Because the above mentioned line does add Leptonica automatically to $LIBS, I've changed this as follows:
AC_CHECK_LIB(lept,pixCreate,[LIBS="-Bstatic -llept -Bdynamic $LIBS"],AC_MSG_ERROR([Leptonica library missing])))
When I run ./configure and make, everything goes right but Tesseract will still be dynamically linked to Leptonica.
While examining the corresponding make log, I noticed that the g++ linking invocation simply ignores my "-Bstatic" attribute and links to the shared library (liblept.so) instead:
libtool: link: g++ -m32 -fPIC -DPIC -shared -nostdlib /usr/lib/gcc/i686-linux-gnu/4.8/../../../i386-linux-gnu/crti.o /usr/lib/gcc/i686-linux-gnu/4.8/crtbeginS.o -Wl,--whole-archive ./.libs/libtesseract_api.a ../ccmain/.libs/libtesseract_main.a ../cube/.libs/libtesseract_cube.a ../neural_networks/runtime/.libs/libtesseract_neural.a ../textord/.libs/libtesseract_textord.a ../wordrec/.libs/libtesseract_wordrec.a ../classify/.libs/libtesseract_classify.a ../dict/.libs/libtesseract_dict.a ../ccstruct/.libs/libtesseract_ccstruct.a ../cutil/.libs/libtesseract_cutil.a ../viewer/.libs/libtesseract_viewer.a ../ccutil/.libs/libtesseract_ccutil.a ../opencl/.libs/libtesseract_opencl.a -Wl,--no-whole-archive -Wl,-rpath -Wl,/home/maxpol/Dokumente/javacpp-presets-myfork/tesseract/cppbuild/linux-x86/lib -Wl,-rpath -Wl,/home/maxpol/Dokumente/javacpp-presets-myfork/tesseract/cppbuild/linux-x86/lib -L/home/maxpol/Dokumente/javacpp-presets-myfork/tesseract/cppbuild/linux-x86/lib/ -lz /home/maxpol/Dokumente/javacpp-presets-myfork/tesseract/cppbuild/linux-x86/lib/liblept.so -lpthread -L/usr/lib/gcc/i686-linux-gnu/4.8 -L/usr/lib/gcc/i686-linux-gnu/4.8/../../../i386-linux-gnu -L/usr/lib/gcc/i686-linux-gnu/4.8/../../../../lib -L/lib/i386-linux-gnu -L/lib/../lib -L/usr/lib/i386-linux-gnu -L/usr/lib/../lib -L/usr/lib/gcc/i686-linux-gnu/4.8/../../.. -lstdc++ -lm -lc -lgcc_s /usr/lib/gcc/i686-linux-gnu/4.8/crtendS.o /usr/lib/gcc/i686-linux-gnu/4.8/../../../i386-linux-gnu/crtn.o -m32 -pthread -Wl,-soname -Wl,libtesseract.so.3 -o .libs/libtesseract.so.3.0.4
I've already consulted the autotools docs and several other projects but couldn't find anything helpful. Therefore I decided myself to ask this question here.
Am I missing something important?
Thank you very much in advance for your help!
Best regards
Max
Related
I have to merge one of my app's libs with the NVIDIA CUDA static lib using this horrific awful CMake code:
GET_TARGET_PROPERTY(OUTPUT_LIB ${LIBNAME} LOCATION)
add_custom_command (TARGET ${LIBNAME}
POST_BUILD
COMMAND mv ${OUTPUT_LIB} ${OUTPUT_LIB}.old
COMMAND echo "create ${OUTPUT_LIB}" > combineLibs.mri
COMMAND echo "addlib ${OUTPUT_LIB}.old" >> combineLibs.mri
COMMAND echo "addlib ${CUDA_LOCATION}" >> combineLibs.mri
COMMAND echo "save" >> combineLibs.mri
COMMAND echo "end" >> combineLibs.mri
COMMAND ar -M <combineLibs.mri
COMMAND rm ${OUTPUT_LIB}.old
COMMENT "Building merged library for ${LIBNAME} at ${OUTPUT_LIB}, including ${CUDA_LOCATION}"
)
target_link_libraries(${LIBNAME} -pthread -c)
This successfully produces a merged static library that has all the symbols in it. However, the NVIDIA CUDA static lib brought with it dependencies on libpthread and libc in the form of unresolved symbols. Now the merged library also has those unresolved symbols, and the target_link_libraries line doesn't seem to do what I seem to think it does, because the symbols don't get resolved at link-time. How do I get the merged static library to dynamically link against libpthread and libc?
The the target_link_libraries line does indeed not do what you think.
target_link_libraries(target,options) can have the desired effect of
adding the linker options options to the linkage of target only if target
is something that is produced by the linker. If no linkage happens in the
production of target then this directive will have no effect.
Your target is a static library. A static library - unlike a program, and unlike
a dynamic/shared library - is not produced by the linker. As your custom_command
in fact illustrates, a static library is produced by the GNU general purpose archiver,
ar. It is nothing but an archive of files which happen to be object files,
but as far as ar is concerned they might as well be the contents of your
Documents, Pictures and Music folders. Since no linkage is involved in the
production of a static library, nothing can be linked with a static library.
An ar archive can be used as a linker input in the linkage of something that
is produced by the linker - a program or a shared library. In that case the
linker will look into the archive to see if contains any object files it needs
to carry on the linkage. If it finds any, it will extract them from the archive
and link them into the program. The linkage will be exactly the same as if
you had listed the required object files in the linker commandline and not
mentioned the archive at all.
But if any of the object files that the linker extracts from an archive bring
with them undefined references, then to get them resolved you must link some
library or libraries that define those references in the linkage of the
program or shared library that you want the linker to produce - just as you
must do to resolve undefined references in any other object files you
input to the linkage.
So,
How do I get the merged static library to dynamically link against libpthread and libc?
You can't. It doesn't make sense. Any library dependencies of object files
in a static library can be satisfied only in the linkage of a program or shared library
that has acquired those dependencies by linking those object files.
Finally, -c is not a GCC linkage option that will have the effect of requesting
linkage of libc. It is not a linkage option at all. It is an option that
directs the GCC frontend not to invoke the linker. It is passed to GCC to
request compilation without linkage, and the perverse effect of including it in a
CMake target_link_libraries directive will be to stop any linkage of the
target from happening.
If you want to explicitly request linkage of libc, use -lc, following
the linker usage protocol that -lname requests linkage of libname.
Perhaps you inferred that -c requests linkage of libc from the assumption
that -pthread requests linkage of libpthread. In fact, -lpthread would
request linkage of libpthread. The option -pthread is a more abstract GCC
option, for both compilation and linkage, that means do the right things, for this platform, to link with the Posix Threads
library - which might entail passing -lpthead to the linker, and possibly not.
Thus -pthread is OK as an argument of target_link_libraries that will
have the effect of requesting Posix Threads linkage, but see
answers to cmake and libpthread
for CMake-proper ways of doing this.
I am trying to compile a source file with icc compiler and MAGMAmic library. However I get the following error:
icc -c -o direct.o direct.c -O3 -openmp -DADD_ -Wall -DHAVE_MIC -I/opt/intel/mic/coi/include -I/usr/include/intel-coi -I/opt/intel/compilers_and_libraries_2017.2.174/linux/mkl/include:/opt/intel/compilers_and_libraries_2017.2.174/linux/ipp/include:/opt/intel/compilers_and_libraries_2017.2.174/linux/mkl/include:/opt/intel/compilers_and_libraries_2017.2.174/linux/tbb/include:/opt/intel/compilers_and_libraries_2017.2.174/linux/daal/include -I/home/dslavchev/install/magmamic-1.4.0/include -I/home/dslavchev/install/magmamic-1.4.0/contol
icc: command line remark #10411: option '-openmp' is deprecated and will be removed in a future release. Please use the replacement option '-qopenmp'
In file included from /home/dslavchev/install/magmamic-1.4.0/include/magma_types.h(134),
from /home/dslavchev/install/magmamic-1.4.0/include/magmablas_z.h(17),
from /home/dslavchev/install/magmamic-1.4.0/include/magmablas.h(12),
from /home/dslavchev/install/magmamic-1.4.0/include/magma.h(17),
from direct.c(21):
/opt/intel/compilers_and_libraries_2017.2.174/linux/compiler/include/complex(30): catastrophic error: cannot open source file "complex"
#include_next <complex>
^
The MAGMAmic library has compiled correctly and I can run it's test ok.
I have looked at the way testing_dgesv_mic.cpp example compiles and used the same includes and link, however in my case I get the above error.
I have added the following in my .bashrc file in order to get the Intel compilers' and libraries' enviromental variables:
#for MAGMA mic
export MAGMA_PATH=/home/dslavchev/install/magmamic-1.4.0
source /opt/intel/bin/compilervars.sh intel64
source /opt/intel/mkl/bin/mklvars.sh intel64
Any ideas what might cause icc to be unable to include the "complex" file?
The file complex really exists in "/opt/intel/compilers_and_libraries_2017.2.174/linux/compiler/include/complex"
icc vesrion is:
[dslavchev#sl051 results]$ icc -v
icc version 17.0.2 (gcc version 4.4.7 compatibility)
magmamic version is magmamic-1.4.0
EDIT: Removed unnecessary code comment
EDIT2: Added version info.
MAGMAmic is a C++ library and it cannot be used with C code directly.
When icc detects that you want to compile .c++ file it automatically switches to icpc (Intel C++ compiler) which in turn results in the above error.
Solution: Either switch to icpc or rename your files to .c++
This question was answered by mark on the MAGMA forums. Link:
http://icl.cs.utk.edu/magma/forum/viewtopic.php?f=2&t=1587&p=4442#p4442
I want to use Armadillo with Eclipse. However all the instructions to link Armadillo is given for Visual Studio. Now I followed the instructions outlined in the ReadMe file of the Armadillo library. I added the Armadillo include folder in project(right click)->properties->C/C++ Build->Settings->Cross G++ Compiler->Includes->Inlcude paths(-I) and then I added the libraries folder (The library folder contain lapack and blas .lib and .dll files) in project(right click)->properties->C/C++ Build->Settings->Cross G++ Linker->Libraries->Library search path (-L).
However when I compile the code in the Eclipse I get the error
.....armadillo_bits/lapack_wrapper.hpp:37: undefined reference to `dgetrf_'.
Shouldn't it simply search for .lib files in the library folder and include them during compiling? I would appreciate any help regarding this matter.
Regards,
TM
Linking the Armadillo library to an Eclipse project can be done and you were about to do it ! It's pretty much the same as for any other library.
In the properties of the project :
GCC C++ Compiler -> Includes : add the path to the file armadillo (where namespace arma is declared) to the include search path (option -I). Example : /home/alpha/soft/armadillo-4.400.1/include
GCC C++ Linker -> Libraries : add the path to the file libarmadillo.so... in the library search path (option -L) Example : /home/alpha/soft/armadillo-4.400.1 . Add armadillo, lapack, blas and m as libraries (option -l). m is for math.
Here are the calls to the compiler and the linker as produced by eclipse :
make all
Building file: ../src/armaeclip.cpp
Invoking: GCC C++ Compiler
g++ -I/home/alpha/soft/armadillo-4.100.1/include -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"src/armaeclip.d" -MT"src/armaeclip.d" -o "src/armaeclip.o" "../src/armaeclip.cpp"
Finished building: ../src/armaeclip.cpp
Building target: armaeclip
Invoking: GCC C++ Linker
g++ -L/home/alpha/soft/armadillo-4.100.1 -o "armaeclip" ./src/armaeclip.o -larmadillo -lblas -lm -llapack
Finished building target: armaeclip
**** Build Finished ****
As you run the code, you might get something like :
error: det(): use of ATLAS or LAPACK needs to be enabled
terminate called after throwing an instance of 'std::logic_error'
what(): det(): use of ATLAS or LAPACK needs to be enabled
Abandon (core dumped)
To avoid this problem, follow the advise of the faq of Armadillo : uncomment #define ARMA_USE_LAPACK in file /home/alpha/soft/armadillo-4.100.1/include/config.hpp and rebuild your project.
You can also create GNU Autotools projects and add following line:
bin_PROGRAMS=armadillo_example
armadillo_example_SOURCES=armadillo_example.cpp
armadillo_example_LDADD=-larmadillo
To Makefile.am file where your source code exist.
If you don't require optimized BLAS libraries, you can use the BLAS and LAPACK libraries that come with Armadillo.
Project properties > C/C++ Build > Settings > GCC C++ Compiler >
Includes > Include paths (-l): C:\armadillo-x.xxx.x\include
Then in Environment Variables > System variables, modify the Path
variable and add: C:\armadillo-x.xxx.x\examples\lib_win64\
Project properties > C/C++ General > Paths and Symbols > Libraries:
blas_win64_MT and lapack_win64_MT (it is important to add them
this way, with no path or .lib/.dll)
Then in Environment Variables > System variables, modify the Path
variable and add: C:\armadillo-x.xxx.x\examples\lib_win64\
And your Armadillo library in Eclipse is good to go.
I've used Eclipse 4.14.0 and Armadillo 9.850.1.
I use Eclipse + ARM plugin to build my projects. When I needed to use in my project the StemWin library, I configured my IDE to use external library.
I set
Preferences -> C/C++ General -> Paths and Symbols
I added in "Library Paths" the link to my folder includes library.
I also added the name of my library in tab "Library".
I checked the settings in the compiler tab and I ascertained all should be good.
When I tried to build my project I got an error from linker:
cannot find -lMyLib.a Hello C/C++ Problem
I double checked the name of my library and link, all are correct. This is the output of my linker:
arm-none-eabi-gcc -mcpu=cortex-m4 -mthumb -mfloat-abi=hard -L"C:\lib"
-T"C:\arm_toolchain\stm32_workspace\Hello\LinkerScript.ld" -Wl,
-Map=output.map -Wl,--gc-sections -o "Hello.elf" #"objects.list" -lMyLib.a
What should I do from here?
I faced the same problem before.
-l:STemWin526_CM4_GCC.a
-L"C:\Edu_Workspace\STM32F4\stm32f4_bsp_template\Drivers\Middlewares\ST\STemWin\Lib"
Above are my working settings.
With -l:<archive file name> the colon : is important for archive file linking.
And -L will contain library path.
Also for stemwin make sure to compile with hardware floating point
-mfloat-abi=hard -mfpu=fpv4-sp-d16
the convention for the -l option of the linker (say you give -lMyLib.a as a linker option) is to search for a library file with "lib" prepended to the given name and .a (or .so) appended, i.e. your command line searches for a file libMyLib.a.{a,so} which is probably not how it's named.
Either you rename your library according to this convention or give it to the linker command line omitting -l (provided your IDE allows you to do so).
Looks like the problem is in -lMyLib.a which means you're trying to link a static library as a dynamic one.
To link a static lib you have to use its path as with ordinary .o files: ... /path/to/MyLib.a
and the resulting command line should look something like
arm-none-eabi-gcc -mcpu=cortex-m4 -mthumb -mfloat-abi=hard -L"C:\lib" -T"C:\arm_toolchain\stm32_workspace\Hello\LinkerScript.ld" -Wl,-Map=output.map -Wl,--gc-sections -o "Hello.elf" #"objects.list" /path/to/MyLib.a
UPDATE:
Although it might fix the issue, turns out it's not true:
-llibrary
-l library
...
Normally the files found this way are library files—archive files whose members are object files. The linker handles an archive file by scanning through it for members which define symbols that have so far been referenced but not defined. But if the file that is found is an ordinary object file, it is linked in the usual fashion. The only difference between using an -l option and specifying a file name is that -l surrounds library with ‘lib’ and ‘.a’ and searches several directories.
(https://gcc.gnu.org/onlinedocs/gcc/Link-Options.html)
I am trying to get started using Rccp and decided to use Eclipse as a development environment since I already use StatEt for R. I am having trouble getting even a simple program to compile and run though, and would appreciate some help!
Briefly I tried to follow the instructions on the blog: http://blog.fellstat.com/?p=170 exactly for setting up Rcpp, RInside and Eclipse, and for the example program. I am running on Mountain Lion, and installed g++ using the command line options in XCode. I think I've faithfully followed all the steps in the blog, but cannot get the program to compile. I think the problem is in the way the header files are included, as indicated from the snippet of the output below. As far as I can tell, line 52 of /usr/include/c++/4.2.1/cstring is an include statement for <string.h> and the compiler includes Rccp/include/string.h instead of the string.h from std that is found earlier on the include path.
I am a novice in C++ so I'd really appreciate some pointers on how to proceed.
-Krishna
16:22:38 **** Incremental Build of configuration Debug for project MyTestRCppPackage ****
Info: Internal Builder is used for build
g++ -DINSIDE -I/Library/Frameworks/R.framework/Versions/2.15/Resources/include -I/Library/Frameworks/R.framework/Versions/2.15/Resources/library/Rcpp/include -I/Library/Frameworks/R.framework/Versions/2.15/Resources/library/Rcpp/include/Rcpp -I/Library/Frameworks/R.framework/Versions/2.15/Resources/library/RInside/include -O0 -g3 -Wall -c -fmessage-length=0 -arch x86_64 -v -o src/main.o ../src/main.cpp
Using built-in specs.
Target: i686-apple-darwin11
Configured with: /private/var/tmp/llvmgcc42/llvmgcc42-2336.11~182/src/configure --disable-checking --enable-werror --prefix=/Applications/Xcode.app/Contents/Developer/usr/llvm-gcc-4.2 --mandir=/share/man --enable-languages=c,objc,c++,obj-c++ --program-prefix=llvm- --program-transform-name=/^[cg][^.-]*$/s/$/-4.2/ --with-slibdir=/usr/lib --build=i686-apple-darwin11 --enable-llvm=/private/var/tmp/llvmgcc42/llvmgcc42-2336.11~182/dst-llvmCore/Developer/usr/local --program-prefix=i686-apple-darwin11- --host=x86_64-apple-darwin11 --target=i686-apple-darwin11 --with-gxx-include-dir=/usr/include/c++/4.2.1
Thread model: posix
gcc version 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.11.00)
/usr/llvm-gcc-4.2/bin/../libexec/gcc/i686-apple-darwin11/4.2.1/cc1plus -quiet -v -I/Library/Frameworks/R.framework/Versions/2.15/Resources/include -I/Library/Frameworks/R.framework/Versions/2.15/Resources/library/Rcpp/include -I/Library/Frameworks/R.framework/Versions/2.15/Resources/library/Rcpp/include/Rcpp -I/Library/Frameworks/R.framework/Versions/2.15/Resources/library/RInside/include -imultilib x86_64 -iprefix /usr/llvm-gcc-4.2/bin/../lib/gcc/i686-apple-darwin11/4.2.1/ -dD -D__DYNAMIC__ -DINSIDE ../src/main.cpp -fPIC -quiet -dumpbase main.cpp -mmacosx-version-min=10.8.3 -m64 -mtune=core2 -auxbase-strip src/main.o -g3 -O0 -Wall -version -fmessage-length=0 -D__private_extern__=extern -o /var/folders/hc/vqp48jt56_v332kc3dqyf5780000gn/T//ccqdmOKI.s
ignoring nonexistent directory "/usr/llvm-gcc-4.2/bin/../lib/gcc/i686-apple-darwin11/4.2.1/../../../../i686-apple-darwin11/include"
ignoring nonexistent directory "/usr/include/c++/4.2.1/i686-apple-darwin11/x86_64"
ignoring nonexistent directory "/Applications/Xcode.app/Contents/Developer/usr/llvm-gcc-4.2/lib/gcc/i686-apple-darwin11/4.2.1/../../../../i686-apple-darwin11/include"
#include "..." search starts here:
#include <...> search starts here:
/Library/Frameworks/R.framework/Versions/2.15/Resources/include
/Library/Frameworks/R.framework/Versions/2.15/Resources/library/Rcpp/include
/Library/Frameworks/R.framework/Versions/2.15/Resources/library/Rcpp/include/Rcpp
/Library/Frameworks/R.framework/Versions/2.15/Resources/library/RInside/include
/usr/llvm-gcc-4.2/bin/../lib/gcc/i686-apple-darwin11/4.2.1/include
/usr/include/c++/4.2.1
/usr/include/c++/4.2.1/backward
/usr/local/include
/Applications/Xcode.app/Contents/Developer/usr/llvm-gcc-4.2/lib/gcc/i686-apple-darwin11/4.2.1/include
/usr/include
/System/Library/Frameworks (framework directory)
/Library/Frameworks (framework directory)
End of search list.
GNU C++ version 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.11.00) (i686-apple-darwin11)
compiled by GNU C version 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.11.00).
GGC heuristics: --param ggc-min-expand=150 --param ggc-min-heapsize=65536
Compiler executable checksum: b37fef824b01c0a99fb2679acf3b04f1
In file included from /usr/include/c++/4.2.1/cstring:52,
from /usr/include/c++/4.2.1/bits/stl_algobase.h:66,
from /usr/include/c++/4.2.1/memory:53,
from /usr/include/c++/4.2.1/tr1/hashtable:56,
from /usr/include/c++/4.2.1/tr1/unordered_map:37,
from /Library/Frameworks/R.framework/Versions/2.15/Resources/library/Rcpp/include/Rcpp/platform/compiler.h:158,
from /Library/Frameworks/R.framework/Versions/2.15/Resources/library/Rcpp/include/RcppCommon.h:26,
from /Library/Frameworks/R.framework/Versions/2.15/Resources/library/Rcpp/include/Rcpp.h:27,
from ../src/main.cpp:8:
/Library/Frameworks/R.framework/Versions/2.15/Resources/library/Rcpp/include/Rcpp/string.h:52: error: 'internal' has not been declared
/Library/Frameworks/R.framework/Versions/2.15/Resources/library/Rcpp/include/Rcpp/string.h:52: error: typedef name may not be a nested-name-specifier
/Library/Frameworks/R.framework/Versions/2.15/Resources/library/Rcpp/include/Rcpp/string.h:52: error: expected ';' before '<' token
/Library/Frameworks/R.framework/Versions/2.15/Resources/library/Rcpp/include/Rcpp/string.h:65: error: expected `)' before 'charsxp'
/Library/Frameworks/R.framework/Versions/2.15/Resources/library/Rcpp/include/Rcpp/string.h:70: error: expected ',' or '...' before '&' token
/Library/Frameworks/R.framework/Versions/2.15/Resources/library/Rcpp/include/Rcpp/string.h:75: error: expected unqualified-id before '&' token
/Library/Frameworks/R.framework/Versions/2.15/Resources/library/Rcpp/include/Rcpp/string.h:75: error: expected ',' or '...' before '&' token
/Library/Frameworks/R.framework/Versions/2.15/Resources/library/Rcpp/include/Rcpp/string.h:75: error: 'Rcpp::String::String()' cannot be overloaded
/Library/Frameworks/R.framework/Versions/2.15/Resources/library/Rcpp/include/Rcpp/string.h:55: error: with 'Rcpp::String::String()'
/Library/Frameworks/R.framework/Versions/2.15/Resources/library/Rcpp/include/Rcpp/string.h:85: error: 'Rcpp::String::String(int)' cannot be overloaded
/Library/Frameworks/R.framework/Versions/2.15/Resources/library/Rcpp/include/Rcpp/string.h:70: error: with 'Rcpp::String::String(int)'
/Library/Frameworks/R.framework/Versions/2.15/Resources/library/Rcpp/include/Rcpp/string.h:88: error: expected `)' before 'x'
/Library/Frameworks/R.framework/Versions/2.15/Resources/library/Rcpp/include/Rcpp/string.h:89: error: expected `)' before 'x'
There are two entirely separate issues here:
Get all you need for Rcpp installed. OS X aspects should be documented on the relevant page maintained by Simon. If you have the tools, and have Rcpp install, then you should be able to do cppFunction('double nPi(int x) { return x*M_PI; }') which is uses functions supplied with Rcpp to create a callable C++ functions accessible to you as nPi() -- and nPi(2) should return a value.
Your choice of IDE and its settings. This is has little to do with 1. apart from requiring it to work to.
So I would work on 1. and see if I got that sorted out first, and only then turn to 2.
To summarize, the issue I faced was that include files in Rcpp with the sames names as those in std were in conflict. In particular, string.h from Rcpp was being included at a point where string.h from std was the right choice, and, as far as I could tell, this was due to the fact that paths specified via the -I directive are searched prior to the default paths.
I tried many different alternatives to solve this, including removing and re-installing XCode and the associated Command Line tools, as well as installing another g++ compiler using macports. None of these resolved the issue. I then used the -idirafter directive instead of the -I directive for the search path for include files for Rcpp and R. I got this hint from gcc include order broken?. This worked since these directories are now searched after the default paths. This precludes (at least so far!) the possibility that string.h from std and string.h from Rcpp come into conflict.
To get step 5 of http://blog.fellstat.com/?p=170 to work I had to set the -idirafter paths in PKG_CPPFLAGS in the file Makevars.
Thanks to everyone for your suggestions.
You simply have to remove include
/Library/Frameworks/R.framework/Resources/library/Rcpp/include/Rcpp
because it is:
unnecessary, as all R imports are in form <Rcpp/XXX>
causes this issue, as compiler looks for string.h in Rcpp directory (when it shouldn't).