clang: error: cannot specify -o when generating multiple output files

After dealing with issues on compiling c code with Matlba2013a in Maverick when using header include files I realized that i needed to to the following mex -v filename.c library.h

but now I get the following error:

clang: error: cannot specify -o when generating multiple output files

Any help would be greatly appreciated.

Thanks

here is the complete verbose:

-----------------------------

**************************************************************************
  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 = $PREF_DIR)
   FILE = /Users/hsanabr/.matlab/R2013a/mexopts.sh
----------------------------------------------------------------
->    MATLAB                = /Applications/MATLAB_R2013a.app
->    CC                    = xcrun  -sdk macosx10.8  clang
->    CC flags:
         CFLAGS             = -fno-common -arch x86_64 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.8.sdk -mmacosx-version-min=10.8 -Dchar16_t=UINT16_T  -fexceptions
         CDEBUGFLAGS        = -g
         COPTIMFLAGS        = -O2 -DNDEBUG
         CLIBS              = /Applications/MATLAB_R2013a.app/bin/maci64/libmx.dylib /Applications/MATLAB_R2013a.app/bin/maci64/libmex.dylib /Applications/MATLAB_R2013a.app/bin/maci64/libmat.dylib -lc++
         arguments          =  -DMX_COMPAT_32
->    CXX                   = xcrun  -sdk macosx10.8  clang++
->    CXX flags:
         CXXFLAGS           = -fno-common -fexceptions -arch x86_64 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.8.sdk -mmacosx-version-min=10.8 -std=gnu++11 -stdlib=libc++
         CXXDEBUGFLAGS      = -g
         CXXOPTIMFLAGS      = -O2 -DNDEBUG
         CXXLIBS            = /Applications/MATLAB_R2013a.app/bin/maci64/libmx.dylib /Applications/MATLAB_R2013a.app/bin/maci64/libmex.dylib /Applications/MATLAB_R2013a.app/bin/maci64/libmat.dylib -lc++
         arguments          =  -DMX_COMPAT_32
->    FC                    = gfortran
->    FC flags:
         FFLAGS             = -fexceptions -m64 -fbackslash
         FDEBUGFLAGS        = -g
         FOPTIMFLAGS        = -O
         FLIBS              = /Applications/MATLAB_R2013a.app/bin/maci64/libmx.dylib /Applications/MATLAB_R2013a.app/bin/maci64/libmex.dylib /Applications/MATLAB_R2013a.app/bin/maci64/libmat.dylib -L -lgfortran -L -lgfortranbegin
         arguments          =  -DMX_COMPAT_32
->    LD                    = xcrun -sdk macosx10.8 clang
->    Link flags:
         LDFLAGS            = -arch x86_64 -Wl,-syslibroot,/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.8.sdk -mmacosx-version-min=10.8 -bundle -Wl,-exported_symbols_list,/Applications/MATLAB_R2013a.app/extern/lib/maci64/mexFunction.map
         LDDEBUGFLAGS       = -g
         LDOPTIMFLAGS       = -O
         LDEXTENSION        = .mexmaci64
         arguments          =  fsconv.h
->    LDCXX                 = 
->    Link flags:
         LDCXXFLAGS         = 
         LDCXXDEBUGFLAGS    = 
         LDCXXOPTIMFLAGS    = 
         LDCXXEXTENSION     = 
         arguments          =  fsconv.h
----------------------------------------------------------------

-> xcrun  -sdk macosx10.8  clang -c  -I/Applications/MATLAB_R2013a.app/extern/include -I/Applications/MATLAB_R2013a.app/simulink/include -DMATLAB_MEX_FILE -fno-common -arch x86_64 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.8.sdk -mmacosx-version-min=10.8 -Dchar16_t=UINT16_T  -fexceptions  -DMX_COMPAT_32 -O2 -DNDEBUG  "wr_gfit.c"

-> xcrun -sdk macosx10.8 clang -O -arch x86_64 -Wl,-syslibroot,/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.8.sdk -mmacosx-version-min=10.8 -bundle -Wl,-exported_symbols_list,/Applications/MATLAB_R2013a.app/extern/lib/maci64/mexFunction.map -o  "wr_gfit.mexmaci64"  wr_gfit.o  fsconv.h /Applications/MATLAB_R2013a.app/bin/maci64/libmx.dylib /Applications/MATLAB_R2013a.app/bin/maci64/libmex.dylib /Applications/MATLAB_R2013a.app/bin/maci64/libmat.dylib -lc++

clang: error: cannot specify -o when generating multiple output files

      mex: link of ' "wr_gfit.mexmaci64"' failed.

Answer 1

[Dekun Pei]

The way mex is used here ("mex -v filename.c library.h") makes "mex" treat the header file "fsconv.h" as an input file and it is being compiled separately.

If the "library.h" is being included in your "filename.c" file, you don't need to provide it to "mex" separately. If the header file is in your current directory, "mex" will find it automatically. If it is not and you get an error regarding not being able to located the header file. Using the "-I" flag to include the location to directory containing the header file as in the following example:

mex filename.c -I/usr/include

Note that there is no space between "-I" and "/usr/include".