Added some documentation for the interface between C and Pascal.

This was necessary because the format of Pascal and C procedure
pointers differ from now on.

diff --git a/doc/pcref.doc b/doc/pcref.doc
index 9326197..b2cd3c3 100644 (file)
--- a/doc/pcref.doc
+++ b/doc/pcref.doc
@@ -413,6 +413,36 @@ for parameters. Some EM implementations check this:
 \*(ONnot checked.
 .I2
 not checked.
+.IE
+.PP
+For those who wish the use the interface between C and Pascal we
+give an incomplete list of corresponding formal parameters in C and Pascal.
+.sp 1
+.ta 8 37
+.nf
+       Pascal  C
+       a:integer       int a
+       a:char  int a
+       a:boolean       int a
+       a:real  double a
+       a:^type type *a
+       var a:type      type *a
+       procedure a(pars)       struct {
+                    void (*a)() ;
+                    char *static_link ;
+               }
+       function a(pars):type   struct {
+                    type (*a)() ;
+                    char *static_link ;
+               }
+.fi
+The Pascal runtime system uses the following algorithm when calling
+function/procedures passed as parameters.
+.nf
+.ta 8 16
+       if ( static_link ) (*a)(static_link,pars) ;
+       else               (*a)(pars) ;
+.fi
 .IT 6.7.2.1
 The order of evaluation of the operands of a dyadic operator
 shall be implementation-dependent.