ruby: slicc: remove member buffer_expr from Var class
This was added by changeset 51f40b101a56. Instead, buffer_expr would now be
associated with the InPort class.

ruby: reverts to changeset: bf82f1f7b040

ruby: slicc: use default argument value
Before this patch, while one could declare / define a function with default
argument values, but the actual function call would require one to specify
all the arguments. This patch changes the check for function arguments.
Now a function call needs to specify arguments that are at least as much as
those with default values and at most the total number of arguments taken
as input by the function.

ruby: replace Address by Addr
This patch eliminates the type Address defined by the ruby memory system.
This memory system would now use the type Addr that is in use by the
rest of the system.

slicc: enable overloading in functions not in classes

For many years the slicc symbol table has supported overloaded functions in
external classes. This patch extends that support to functions that are not
part of classes (a.k.a. no parent). For example, this support allows slicc
to understand that mapAddressToRange is overloaded and the NodeID is an
optional parameter.

slicc: improved stalling support in protocols

Adds features to allow protocols to reschedule controllers when conditionally
stalling within inport logic or actions. Also insures that resource and
protocol stalls are re-evaluated the next cycle.

slicc: support for multiple message types on the same buffer

This patch allows SLICC protocols to use more than one message type with a
message buffer. For example, you can declare two in ports as such:

in_port(ResponseQueue_in, ResponseMsg, responseFromDir, rank=3) { ... }
in_port(tgtResponseQueue_in, TgtResponseMsg, responseFromDir, rank=2) { ... }

ruby: slicc: replace max_in_port_rank with number of inports

This patch replaces max_in_port_rank with the number of inports. The use of
max_in_port_rank was causing spurious re-builds and incorrect initialization
of variables in ruby related regression tests. This was due to the variable
value being used across threads while compiling when it was not meant to be.

Since the number of inports is state machine specific value, this problem
should get solved.

ruby: slicc: remove double trigger, continueProcessing
These constructs are not in use and are not being maintained by any one.
In addition, it is not known if doubleTrigger works correctly with Ruby now.

ruby: allow function definition in slicc structs
This patch adds support for function definitions to appear in slicc structs.
This is required for supporting functional accesses for different types of
messages. Subsequent patches will use this to development.

Change interface between coherence protocols and CacheMemory
The purpose of this patch is to change the way CacheMemory interfaces with
coherence protocols. Currently, whenever a cache controller (defined in the
protocol under consideration) needs to carry out any operation on a cache
block, it looks up the tag hash map and figures out whether or not the block
exists in the cache. In case it does exist, the operation is carried out
(which requires another lookup). As observed through profiling of different
protocols, multiple such lookups take place for a given cache block. It was
noted that the tag lookup takes anything from 10% to 20% of the simulation
time. In order to reduce this time, this patch is being posted.

I have to acknowledge that the many of the thoughts that went in to this
patch belong to Brad.

Changes to CacheMemory, TBETable and AbstractCacheEntry classes:
1. The lookup function belonging to CacheMemory class now returns a pointer
to a cache block entry, instead of a reference. The pointer is NULL in case
the block being looked up is not present in the cache. Similar change has
been carried out in the lookup function of the TBETable class.
2. Function for setting and getting access permission of a cache block have
been moved from CacheMemory class to AbstractCacheEntry class.
3. The allocate function in CacheMemory class now returns pointer to the
allocated cache entry.

Changes to SLICC:
1. Each action now has implicit variables - cache_entry and tbe. cache_entry,
if != NULL, must point to the cache entry for the address on which the action
is being carried out. Similarly, tbe should also point to the transaction
buffer entry of the address on which the action is being carried out.
2. If a cache entry or a transaction buffer entry is passed on as an
argument to a function, it is presumed that a pointer is being passed on.
3. The cache entry and the tbe pointers received __implicitly__ by the
actions, are passed __explicitly__ to the trigger function.
4. While performing an action, set/unset_cache_entry, set/unset_tbe are to
be used for setting / unsetting cache entry and tbe pointers respectively.
5. is_valid() and is_invalid() has been made available for testing whether
a given pointer 'is not NULL' and 'is NULL' respectively.
6. Local variables are now available, but they are assumed to be pointers
always.
7. It is now possible for an object of the derieved class to make calls to
a function defined in the interface.
8. An OOD token has been introduced in SLICC. It is same as the NULL token
used in C/C++. If you are wondering, OOD stands for Out Of Domain.
9. static_cast can now taken an optional parameter that asks for casting the
given variable to a pointer of the given type.
10. Functions can be annotated with 'return_by_pointer=yes' to return a
pointer.
11. StateMachine has two new variables, EntryType and TBEType. EntryType is
set to the type which inherits from 'AbstractCacheEntry'. There can only be
one such type in the machine. TBEType is set to the type for which 'TBE' is
used as the name.

All the protocols have been modified to conform with the new interface.

ruby: Stall and wait input messages instead of recycling

This patch allows messages to be stalled in their input buffers and wait
until a corresponding address changes state. In order to make this work,
all in_ports must be ranked in order of dependence and those in_ports that
may unblock an address, must wake up the stalled messages. Alot of this
complexity is handled in slicc and the specification files simply
annotate the in_ports.

slicc: have a central mechanism for creating a code_formatter.
This makes it easier to add global variables like protocol

slicc: Pure python implementation of slicc.
This is simply a translation of the C++ slicc into python with very minimal
reorganization of the code. The output can be verified as nearly identical
by doing a "diff -wBur".

Slicc can easily be run manually by using util/slicc