buildfile: try harder to find non-Mex fortran compiler

Author: scivision

buildfile.m

@@ -143,19 +143,7 @@ function build_exe(context)
     case "fortran"
       comp = getenv("FC");
       if isempty(comp)
-        disp("set FC environment variable to the Fortran compiler path, or do 'mex -setup fortran'")
-        if ismac()
-          p = '/opt/homebrew/bin/';
-          for fc = ["flang", "gfortran"]
-            comp = stdlib.which(fc, p);
-            if ~isempty(comp)
-              % disp(lang + " compiler: " + comp)
-              setenv("FC", comp);
-              return
-            end
-          end
-          disp("on macOS, environment variables propagate in to GUI programs like Matlab by using 'launchctl setenv FC' and a reboot. Or by using 'FC=gfortran matlab -batch buildtool exe'")
-        end
+        comp = get_fortran_compiler();
       end
     case "c++"
       comp = getenv("CXX");
@@ -174,7 +162,6 @@ function build_exe(context)
   % disp(lang + " compiler: " + co.ShortName + " " + co.Name + " " + co.Version + " " + comp)
 end
 
-
 shell = string.empty;
 if ispc() && ~isempty(co)
   disp("Shell: " + co.Details.CommandLineShell)
@@ -298,3 +285,28 @@ function build_exe(context)
 end
 
 end
+
+
+function comp = get_fortran_compiler()
+
+disp("set FC environment variable to the Fortran compiler path, or do 'mex -setup fortran'")
+
+if ismac()
+  p = '/opt/homebrew/bin/';
+  disp("on macOS, environment variables propagate in to GUI programs like Matlab by using 'launchctl setenv FC' and a reboot.")
+  disp("if having trouble, try:")
+  disp("  FC=gfortran matlab -batch 'buildtool exe'")
+else
+  p = '';
+end
+
+for fc = ["flang", "gfortran", "ifx"]
+  comp = stdlib.which(fc, p);
+  if ~isempty(comp)
+    % disp(lang + " compiler: " + comp)
+    setenv("FC", comp);
+    return
+  end
+end
+
+end