This patch itself is not valid until all invokers of DEVdestroy()
(currently this is CKTdestroy() exclusively)
are rewritten to invoke DEVmodDelete() and DEVdelete()
and use a more robust test for local node numbers.
That is, transform this pattern :
if (here->Node && ...) {
CKTdltNNum(ckt, here->Node);
here->Node = 0;
}
into this :
if (here->Node > 0 && ...)
CKTdltNNum(ckt, here->Node);
here->Node = 0;
The change of "!= 0" ==> "> 0" accounts for rare cases where "Node"
might have been set to -1, (meaning "unconnected")
The unconditional execution of the zero assignment is for those cases
where "Node" might have been assigned to some external or other local Node.
If so, the variable would not be set to zero, confusing the "guarding" if's
in the corresponding XXXsetup() routine.
The Pattern to follow is:
1) unset and delete *all* local Nodes in XXXunsetup()
2) allocate all of them again in a re-invocation of XXXsetup(),
exactly the same way as in the very first invocation.
for almost all other external nodes (notable exception "txl")
src/spicelib/devices/*/*def*.h, declare external node variables const
1) The compiler shall emit an error message if we still mess around
with external node numbers.
2) To mark which elements of the instance struct are meant to be set
externally when parsing the netlist
These "external" node variables are exclusively set via the
overlay struct GENinstance, member GENnode[]
We shall not mess around with these "external" node variables
because it would get rather difficult to avoid bugs considering
re-invocation of the XXXsetup() routine.
This gets interesting for devices with optional ports,
which get copied around depending on the amount of connected ports.
All locally created nodes (CKTmk..() invocations in XXXsetup())
must be deleted in XXXunsetup()
Otherwise CKTmk..() invocations during a following CKTsetup()
will re-emit still used node numbers,
thus accidentally shorting nodes.
This patch fixes a little bit more complex cases,
which are local node variables which will start with value 0
and eventually be set with the result of a CKTmk..() invocations,
but might as well receive a node number from another node variable.
Here CKTdltNNum() must not be invoked if the node number is merely
a copy from another node variable.
All locally created nodes (CKTmk..() invocations in XXXsetup())
must be deleted in XXXunsetup()
Otherwise CKTmk..() invocations during a following CKTsetup()
will re-emit still used node numbers,
thus accidentally shorting nodes.
This patch fixes the simple cases,
which are local node variables which will start with value 0
and eventually be set with the result of a CKTmk..() invocation.
More complex cases evolve, if such a local variable might receive
a node number which origins from another node, or the netlist itself.
Invoke CKTdltNNum() in reverse order of local node creation in XXXsetup()
This fixes a bug at least in mesa and hfet1,
where already destroyed node variables have still been accessed
in the guarding 'if' of a later CKTdltNNum() stanza.
Invoking them in revers order easily prevents such bugs,
and improves readability.
rlar
dwarning
h_vogt
Henrik Forsten
Francesco Lannutti