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diff --git a/unix/os/doc/zlocva.hlp b/unix/os/doc/zlocva.hlp new file mode 100644 index 00000000..1239fa40 --- /dev/null +++ b/unix/os/doc/zlocva.hlp @@ -0,0 +1,47 @@ +.help zlocva May84 "System Interface" +.ih +NAME +zlocva -- get the memory address of a variable +.ih +SYNOPSIS +.nf +zlocva (object, address) + +arb object # reference to variable +int address # value of the reference +.fi +.ih +DESCRIPTION +The memory address of \fIobject\fR in char storage units is returned as +the value of the integer variable \fIaddress\fR. The referenced object +may be a variable or array element of actual datatype \fBcsilrdx\fR. +The referenced object may \fInot\fR be a procedure or a Fortran character +variable. +.ih +RETURN VALUE +The memory address returned references the process logical address space +\fIin units of SPP chars\fR. No zero point is assumed. +.ih +NOTES +We assume that the maximum address in char units will fit into a signed +integer variable. The high level code assumes that it can do signed integer +comparisons and arithmetic operations (additions and subtractions) upon the +addresses returned by \fBzlocva\fR to check arrays for equality and overlap +and to compute offsets when generating pointers into Mem. +Negative addresses are permitted provided the signed arithmetic and +comparison operations work properly, i.e., provided the negative addresses +are assigned to the first half of the process logical address space. +The following relationship must hold: + +.nf + call locva (Memc[1], addr1) + call locva (Memc[2], addr2) + if (addr2 - addr1 == 1 for all possible locations of Memc) + locva conforms to the standard +.fi + +\fBMemc\fR is an SPP char array in the global common \fBMem\fR. +.ih +SEE ALSO +zmaloc, zlocpr +.endhelp |