Error using PROC PROTOand FCMP to call an external C function with a struct

[jklaverstijn]

Hi,

I am trying to call functions from a C library and get stuck on a function that returns a pointer to a struct of which the definition is hidden inside compiled code. I use PROC PROTO and PROC FCMP for this after failing with MODULEN() (another story). There are many functions in the library. Another one worked but has a very simple definition. My code is below. I have added a bogus definition for the struct stXC_HANDLE as I have no idea either how to get that from the external library.

proc proto package=work.proto.cdefs;
   link '/opt/thirdparty/xyz/pqr/bin/libxcpep.so';

   struct stXC_HANDLE {
      double hi;
      long * low;
   };
   typedef struct stXC_HANDLE *XC_HANDLE;
   typedef char XC_CHAR;
   int XCInitLib(XC_HANDLE* phXCHandle, const XC_CHAR* pcParameter);
run;

proc fcmp inlib=work.proto outlib=work.proto.fcmp;
	function sas_xcinitlib(handle, parameter $);
	   outargs handle;
	   struct stXC_HANDLE handle;
	   rc = XCInitLib(handle, parameter);
	   return (rc);
	endsub;
run;

options cmplib=(work.fcmp work.proto);
data _null_;
	   length parameter $20;
	   parameter = '';
	   handle = 0x;
	   rc_init = sas_xcinitlib(addrlong(handle), parameter);
	   put _all_;
run; 

When I run this I get this log from proc FCMP:

43         	function sas_xcinitlib(handle, parameter $);
44         	   outargs handle;
45         	   struct stXC_HANDLE handle;
46         	   rc = XCInitLib(handle, parameter);
ERROR: Cannot promote a scalar to a '**' for argument 1 in function XCInitLib.
47         	   return (rc);
48         	endsub;
49         run;

What am I doing wrong here? More specifically:

- How can I use struct stXC_HANDLE from the external library?

- How can I avoid the above error?

This is SAS 9.4M4 on Linux x86_64 (RHEL 7.3).

Many thanks in advance for your input,

-- Jan.

[FriedEgg]

@jklaverstijn, At least part of your issue may be related to this.  I would submit a ticket to SAS Technical Support to corroborate this.