How to use a variable in the mex compiling code sentence?

I am currently using the following mex compiling code sentence (successfully):

mex GCC='/usr/bin/gcc-11' -I/usr/local/include -L/usr/local/lib -lsundials_cvode -lsundials_nvecserial -lm MyFile_cvode.c

I would like to update my code to specify the file MyFile_cvode.c using a variable. i.e. something like

FileChoice=MyFile_cvode.c;
mex GCC='/usr/bin/gcc-11' -I/usr/local/include -L/usr/local/lib -lsundials_cvode -lsundials_nvecserial -lm FileChoice

I've read that in order to accomplish this, I need to switch from using sentence syntax to function syntax. However, I'm very new to mex and I don't understand the syntax well enough to understand how to make the conversion correctly.

I've tried:

mex('GCC="/usr/bin/gcc-11"','-I/usr/local/include','-L/usr/local/lib','-lsundials_cvode', '-lsundials_nvecserial', '-lm', 'MyFile_cvode.c')  

but this produced errors.

Answer 1

[Laura]

Answered my own question!

Syntax should have been

mex( 'MyFile_cvode.c','GCC="/usr/bin/gcc-11"','-I/usr/local/include','-L/usr/local/lib','-lsundials_cvode', '-lsundials_nvecserial', '-lm')

or

FileChoice='MyFile_cvode.c';

mex(FileChoice,'GCC="/usr/bin/gcc-11"','-I/usr/local/include','-L/usr/local/lib','-lsundials_cvode', '-lsundials_nvecserial', '-lm')

i.e. file to be compiled listed first.

Answer 2

[dpb]

function mymex(file)
% build and execute mex for given input file
  cmd="GCC='/usr/bin/gcc-11' -I/usr/local/include -L/usr/local/lib -lsundials_cvode -lsundials_nvecserial -lm ";
  cmd=cmd + file;               % append the input file to compile
  mex(cmd)                      % dispatch to mex
end

CAUTION: AIR CODE! Don't have mex compiler installed at the moment so can't do a hard test.

The problem in your attempt is mex command is one long string, not a set of independent input parameters so separating the arguments with commas isn't correct synatax. Then, you enclosed your filename in quotes so it became a fixed constant, not substituting in the variable name.

The above takes all the command line fixed arguments and then adds the input file name as one long string; then calls mex as a function with that long commnd line. I did test that mex() will accept the string variable by running

cmd="-help";
mex(cmd)

MEX   Compile MEX-function

   Usage:
       mex [options ...] file [files ...]

   Description:
       MEX compiles and links source files into a shared library called a
       MEX-file, executable from within MATLAB. It also builds executable
       files for standalone MATLAB engine and MAT-file applications.

   Command Line Options Available on All Platforms:
       -c
           Compile only. Creates an object file but not a MEX-file.
       -client engine
           Build standalone MATLAB engine or MAT-file application.
       -compatibleArrayDims
           Build a MEX-file using the MATLAB Version 7.2 array-handling
           API, which limits arrays to 2^31-1 elements.
       -D<name>
           Define a symbol name to the C preprocessor. Equivalent to a
           "#define <name>" directive in the source. Do not add a space
           after this switch.
       -D<name>=<value>
           Define a symbol name and value to the C preprocessor. Equivalent
           to a "#define <name> <value>" directive in the source. Do not
           add a space after this switch.
       -f <optionsfile>
           For advanced users. Specify location and name of the MEX
           configuration file to use. Overrides MEX's default compiler
           selection mechanism.
       -g
           Adds symbolic information and disables optimizing built object code.
	   Use for debugging.
       -h[elp]
           Display this message.
       -I<pathname>
           Add <pathname> to the list of directories to search for #include
           files. Do not add a space after this switch.
       -l<name>
           Link with object library. On Windows, <name> expands to
           "<name>.lib" or "lib<name>.lib". On Linux, to "lib<name>.so".
           On Mac, to "lib<name>.dylib". Do not add a space after this
           switch.
       -L<folder>
           Add <folder> to the list of folders to search for
           libraries specified with the -l option. Do not add a space
           after this switch.
       -largeArrayDims
           Build a MEX-file using the MATLAB large-array-handling API.
           This API can handle arrays with more than 2^31-1 elements when
           compiled on 64-bit platforms.
       -R2017b
           Build a MEX-file using the MATLAB large-array-handling, and
           graphics-objects APIs. This option is available on 64-bit
           platforms. The API can handle arrays with more than
           2^31-1 elements. -R2017b is the default option.
       -R2018a
           Build a MEX-file using the MATLAB large-array-handling,
           graphics-objects, and interleaved-complex APIs. This option
           is available on 64-bit platforms. The API can handle arrays
           with more than 2^31-1 elements, and supports type-safe and
           interleaved complex data access.
       -n
           No execute mode. Display commands that MEX would otherwise
           have executed, but do not actually execute any of them.
       -O
           Optimizes the object code. Use this option to compile with optimization.
	   Optimization is enabled by default. Specify this option with the 
 	   capital letter O.
       -outdir <dirname>
           Place all output files in folder <dirname>.
       -output <resultname>
           Create MEX-file named <resultname>. The appropriate MEX-file
           extension is automatically appended. Overrides MEX's default
           MEX-file naming mechanism.
       -setup <lang>
           Change the default compiler to build <lang> language MEX-files.
           When this option is specified, no other command line
           input is accepted.
       -silent
           Suppress informational messages. The mex function still reports
           errors and warnings, even when you specify -silent.
       -U<name>
           Remove any initial definition of the C preprocessor symbol
           <name>. (Inverse of the -D option.) Do not add a space after
           this switch.
       -v
           Verbose mode. Display the values for important internal
           variables after all command line arguments are considered.
           Displays each compile step and final link step fully evaluated.
       <name>=<value>
           Override default setting for variable <name>. This option is
           processed after all command line arguments are considered.

   Command Line Options Available Only on Windows Platforms:
       @<rspfile>
           Include contents of the text file <rspfile> as command line
           arguments to MEX.

   For more information, see
           http://www.mathworks.com/help/matlab/ref/mex.html

which shows mex was called with the passed argument string.

Use as

mymex('MyDesiredFile.c')