On 2015-04-30, at 16:23, Ed Jaffe wrote:

> A working program had the following code:
> 
> 018000              MVC   0(8,R1),=CL8'EJESPOP'     Set command name
> 018010              MVC   8(8,R1),=CL8'PATHNAME'    Set command parameter
> 
> An overzealous programmer, trying to be helpful, changed it to:
> 
> 018000              MVC   0(16,R1),=CL8'EJESPOP PATHNAME' Set cmd name/parm
> 
> which introduced a problem that wasn't discovered until a very inopportune 
> time.
> 
> Of course, there is no substitute for thorough testing. But, it occurs to me 
> that the assembler could issue a warning when data is lost from truncation as 
> the result of a nominal value requiring more bytes than are explicitly 
> specified via a length modifier.
>  
It should have been reported as an error aboriginally.  Programmers
can use substring constructs when necessary.

It's too late to fix it now.

-- gil

Reply via email to