DOCERR: Mixed-Language Examples for Calling Pascal Are Incorrect

MS-DOS                 | OS/2       | WINDOWS

The information in this article applies to:

• Microsoft C for MS-DOS, versions 6.0, 6.0a, and 6.0ax
• Microsoft C for OS/2, versions 6.0 and 6.0a
• Microsoft C/C++ for MS-DOS, version 7.0
• Microsoft Visual C++ for Windows, versions 1.0 and 1.5

SUMMARY

In the "Microsoft C Advanced Programming Techniques" manual (APT) that shipped with Microsoft C versions 6.0, 6.0a, and 6.0ax, the "Microsoft C/C++ Programming Techniques" manual that shipped with version 7.0, the "Microsoft Mixed-Language Programming Guide" provided with C versions 5.0 and 5.1, MASM versions 5.0 and 5.1, and Pascal version 4.0, there is a sample Pascal module, Pfun, that is incorrect. Pfun can be found in the following locations:

In the APT

• Page 295, Section 12.7.2 "Calling a Pascal Function from C"

In the Programming Techniques manual

• Page 248, Section 11.7 "Calling a Pascal Function from C" (7.0)
• Page 173, Section 8.7 "Calling a Pascal Function from C" (8.0)

In the Mixed-Language Guide

• Page 30, Section 2.5.2 "Calling Pascal from Basic -- Function Call"
• Page 44, Section 3.5.2 "Calling Pascal from C -- Function Call"
• Page 57, Section 4.5.2 "Calling Pascal from FORTRAN -- Function

If the Pascal source code shown on these pages is compiled, the following errors occur:

  21  7   begin
= 22  8     Fact := Fact * n;
      8  --------------^Warning 171 Insert (
      8  ----------------^268 Cannot Begin Expression  Skipped
      8  -------------------^Warning 155 ; Assumed ,
      8  -------------------^257 Parameter List Size Wrong Begin Ski

MORE INFORMATION

To obtain correctly compiled code, all of the incorrect references to Fact must be removed and replaced by a temporary variable. The following source code contains the necessary changes to the Pfun module so that it will compile and run without any errors:

module Pfun;

  function Fact (n : integer) : integer;

  var   temp : integer;

  begin
     temp := 1;
     while n > 0 do
        begin
            temp := temp * n;
            n := n - 1;
        end;
     Fact := temp;
  end;

Note: There is an incorrect reference to the errors in the Fact function in the Pascal version 4.0 README.DOC file. This correction does not work properly.