The MATLAB interface does not pass the recursive test on macOS and Windows

[zaikunzhang]

The MATLAB interface does not pass the recursive test on macOS and Windows, even if the recursion depth is only one:

https://github.com/libprima/prima/blob/main/matlab/tests/recursive.m

The same test succeeds on Linux. See

https://github.com/sprimalib/prima/actions/runs/6247172429

Is this a limitation of MATLAB, OS, or PRIMA?

[zaikunzhang]

Update: The Windows / macOS test does not always fail. This is even stranger.

https://github.com/sprimalib/prima/actions/runs/6247172429

[zaikunzhang]

Fixed by adding -assume recursion (macos) or /assume:recursion (windows) to the flags of ifort. See

prima/matlab/setup_tools/compile.m

Lines 62 to 92 in 65267f3

	% Modify the compiler options by revising FFLAGS or COMPFLAGS.
	% See https://www.mathworks.com/help/matlab/ref/mex.html
	% 1. We force the Fortran compiler to allocate arrays on the heap instead of the stack. Otherwise,
	% the solvers will encounter stack overflow when the problem size is large. As of gfortran 12.0,
	% `-fno-stack-arrays` is indeed the default, and we specify it for safety; as of Intel oneAPI
	% 2023.1.0, `-no-heap-arrays` is the default, so we must specify `-heap-arrays`.
	% N.B.: We assume that the function evaluation is much more expensive than the memory allocation,
	% so the performance loss due to the heap allocation is negligible. This is true for derivative-free
	% optimization, but may not be true for optimization with derivatives.
	% 2. We require the Fortran compiler to compile the solvers so that they can be called recursively.
	% Otherwise, the solvers will not work properly in recursive invocations. See
	% https://fortran-lang.discourse.group/t/frecursive-assume-recursion-and-recursion-thread-safety
	compiler_configurations = mex.getCompilerConfigurations('fortran', 'selected');
	if contains(compiler_configurations.Manufacturer, 'gnu', 'IgnoreCase', true) % gfortran
	extra_compiler_options = '-fno-stack-arrays -frecursive';
	elseif contains(compiler_configurations.Manufacturer, 'intel', 'IgnoreCase', true) % Intel compiler
	if ispc
	extra_compiler_options = '/heap-arrays /assume:recursion';
	else
	extra_compiler_options = '-heap-arrays -assume recursion';
	end
	else
	warning('prima:UnrecognizedCompiler', 'Unrecognized compiler %s. The package may not work.', ...
	compiler_configurations.Name);
	extra_compiler_options = '';
	end
	if ispc % Windows
	compiler_options = ['COMPFLAGS="$COMPFLAGS ', extra_compiler_options, '"'];
	else
	compiler_options = ['FFLAGS="$FFLAGS ', extra_compiler_options, '"'];
	end

https://fortran-lang.discourse.group/t/frecursive-assume-recursion-and-recursion-thread-safety