How to create SML / NJ executable on Mac

Question

I have an SML / NJ program that I can run as a heap, and I want to create a standalone binary executable. However, the heap2exec tool in SML / NJ 110.73 always gives errors for me.

I created a tigerc.x86-darwin heap image through the following:

 ml-build sources.cm Main.main tigerc 

I can run my program using a heap image using

 sml @SMLload=tigerc.x86-darwin 

I should be able to create standalone binaries via

 heap2exec tigerc.x86-darwin tigerc 

but it generates an error

 ld: warning: -macosx_version_min not specificed, assuming 10.7 ld: warning: ignoring file tigerc.o, file was built for unsupported file format which is not the architecture being linked (i386) 

I looked at the heap2exec script shell, and the key lines (with a variable extension) did the following:

 heap2asm "$heapfile" "$execfile".s cc -c -o "$execfile".o "$execfile".s ld -o "$execfile" ${RUNX} "$execfile".o 

When I perform these steps individually, the cc command creates the x86_64 .o file, but the ld command tries to link the i386 executable. Therefore, I need to convince the cc command to generate the i386 .o file.

Is there a way to set the environment variable to get cc for i386 build instead of x86_84? ( ARCH doesn't do the trick, by the way - it's already installed in i386 .)

Or is there another workaround to get heap2exec to create the correct architecture?

Answer 1

Try adding CFLAGS=-m32 as an environment variable. This is the standard way to force it to create a 32-bit object file.

I know that you are specifically asking about SML / NJ, but MLton supports the 64-bit version and makes this task very simple. You can thank yourself later if you are able to use it to generate executable binary files.