How to compile shrlibsample in R2012a

Folks,

I see good documentation on how to use the compiled example that ships with R2012a, but I don't see how to compile it, specifically the shrlibsample. Can someone point me to some documentation or answer how one should compile it? I'm asking this also because I can't seem to get structures to work the way they're supposed to, and doing things the "Matlab way" might make things work.

[Konrad Malkowski]

What operating system?

[Steven]

Redhat Enterprise 6. Linux.

Answer 1

[Konrad Malkowski]

You can compile the code in two ways: - using gcc - using mex (which uses gcc internally)

Here's how I compiled the code using gcc.

1. Navigate to matlabroot/extern/examples/shrlib
2. Compile the library
3. % gcc -c shrlibsample.c -shared -I matlabroot/extern/include -fPIC -o shrlibsample.o
4. % gcc -shared -Wl,-soname,libshrsample.so.1 -o libshrsample.so.1.0.1 shrlibsample.o

Now you will have a file names libshrsample.so.1.0.1 in the directory

Start MATLAB. Navigate to matlabroot/extern/examples/shrlib

hfile = fullfile(pwd,'shrlibsample.h')

>> loadlibrary('libshrsample.so.1.0.1',hfile)
Warning: The library name is not a valid name.
The library will be named "libshrsample0x2Eso0x2E10x2E0". 
> In loadlibrary at 174 
>> struct.p1 = 4; struct.p2 = 7.3; struct.p3 = -290

struct = 

      p1: 4
      p2: 7.3000
      p3: -290

>> [res, st] = calllib('libshrsample0x2Eso0x2E10x2E0', 'addStructByRef', struct)

res =

    -279

st = 

      p1: 5.5000
      p2: 1234
      p3: 12345678

>>

(For more info on this example see the "calllib" help page).

You can also compile the code using mex.

>> cd ../extern/examples/shrlib/
>> hfile = fullfile(pwd,'shrlibsample.h')

hfile =

<matlabroot>/extern/examples/shrlib/shrlibsample.h

>> mex -v shrlibsample.c LDFLAGS="-shared -Wl"

**************************************************************************
  Warning: Neither -compatibleArrayDims nor -largeArrayDims is selected. 
           Using -compatibleArrayDims. In the future, MATLAB will require
           the use of -largeArrayDims and remove the -compatibleArrayDims
           option. For more information, see:
           http://www.mathworks.com/help/matlab/matlab_external/upgrading-mex-files-to-use-64-bit-api.html
**************************************************************************

-> mexopts.sh sourced from directory (DIR = $MATLAB/bin)
   FILE = <matlabroot>/bin/mexopts.sh
----------------------------------------------------------------
->    MATLAB                = <matlabroot>
->    CC                    = gcc
->    CC flags:
         CFLAGS             = -ansi -D_GNU_SOURCE  -fexceptions -fPIC -fno-omit-frame-pointer -pthread
         CDEBUGFLAGS        = -g
         COPTIMFLAGS        = -O -DNDEBUG
         CLIBS              = -Wl,-rpath-link,<matlabroot>/bin/glnxa64 -L<matlabroot>/glnxa64 -lmx -lmex -lmat -lm -lstdc++
         arguments          =  -DMX_COMPAT_32
->    CXX                   = g++
->    CXX flags:
         CXXFLAGS           = -ansi -D_GNU_SOURCE -fPIC -fno-omit-frame-pointer -pthread
         CXXDEBUGFLAGS      = -g
         CXXOPTIMFLAGS      = -O -DNDEBUG
         CXXLIBS            = -Wl,-rpath-link,<matlabroot>/glnxa64 -L<matlabroot>/bin/glnxa64 -lmx -lmex -lmat -lm
         arguments          =  -DMX_COMPAT_32
->    FC                    = gfortran
->    FC flags:
         FFLAGS             = -fexceptions -fbackslash -fPIC -fno-omit-frame-pointer
         FDEBUGFLAGS        = -g
         FOPTIMFLAGS        = -O
         FLIBS              = -Wl,-rpath-link,<matlabroot>/bin/glnxa64 -L<matlabroot>/bin/glnxa64 -lmx -lmex -lmat -lm
         arguments          =  -DMX_COMPAT_32
->    LD                    = gcc
->    Link flags:
         LDFLAGS            = -shared -Wl
         LDDEBUGFLAGS       = -g
         LDOPTIMFLAGS       = -O
         LDEXTENSION        = .mexa64
         arguments          = 
->    LDCXX                 = 
->    Link flags:
         LDCXXFLAGS         = 
         LDCXXDEBUGFLAGS    = 
         LDCXXOPTIMFLAGS    = 
         LDCXXEXTENSION     = 
         arguments          = 
----------------------------------------------------------------

-> gcc -c  -I<matlabroot>/extern/include -I<matlabroot>/simulink/include -DMATLAB_MEX_FILE -ansi -D_GNU_SOURCE  -fexceptions -fPIC -fno-omit-frame-pointer -pthread  -DMX_COMPAT_32 -O -DNDEBUG  "shrlibsample.c"

-> gcc -O -shared -Wl -o  "shrlibsample.mexa64"  shrlibsample.o  -Wl,-rpath-link,<matlabroot>/bin/glnxa64 -L<matlabroot>/bin/glnxa64 -lmx -lmex -lmat -lm -lstdc++

>> loadlibrary('shrlibsample',hfile)
>> struct.p1 = 4; struct.p2 = 7.3; struct.p3 = -290

struct = 

      p1: 4
      p2: 7.3000
      p3: -290

>> [res, st] = calllib('shrlibsample', 'addStructByRef', struct)

res =

    -279

st = 

      p1: 5.5000
      p2: 1234
      p3: 12345678

>> 
>>

[Philip Borghesani]

I like the shared library versioning in the first example but hate the generated name try:

loadlibrary('libshrsample.so.1.0.1',hfile,'alias','sample')
[res, st] = calllib('sample', 'addStructByRef', struct)