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Why do vpi_ do call back registered functions return 'int' instead of 'void'
It seems to me the vpi_ simulation related registered call back function
in the s_cb_data type (LRM section 23.34, p. 584) and system task or
function call back routines in s_vpi_systf_data (LRM section 23.25, p. 589)
should have type "void returning function" instead of "int returning
function". And in fact the example on page 588 is code this way and
I think wrong since a void returning call back function 'get_current_cputime'
is registered in the example.
I discovered this trying to run some vpi_ code through a lint program.
In order to take advantage of the checking ability of ansii C, registered
functions must be declared as int returning and must explicitly return
some kind of dummy value (probably 0).
In addition to the advantage of allowing lint warning checking changing
the fields to void returning allows optimizing C compilers to
produce much better code.
The s_vpi_vlog_info type defined in vpi_user.h for defining start up
call back routines does require void returning routines.
I could not find any use for either s_cb_data call back or s_vpi_systf_data
routine int return value in the LRM. Is there something I am missing on
this? Since the s_vpi_time type is already being changed, now might be
a good time to also change the cb_rtn declarations.
/Steve
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