python: Make the dot writer handle unconnected Port vector elements.

Change-Id: I5234013716cdcce5fc39e239dc3d92cd1f2b7799
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/20699
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>

misc: dot_writer fixup

In large configs the tooltip may be greater then the maximum line
size graphviz supports when parsing the dot file (typically 16k).
Adding '/' causes graphviz to break the string in multiple lines
while parsing and works around this limitation.

Change-Id: I16a0030127de4165080de97f5213309eed9fdeca
Signed-off-by: Tiago Mück <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/19208
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>

python: Generalize the dot_writer to handle non Master/Slave roles.

Change-Id: I6d93c28e754c0cacacdd5e8885c45bc861135e94
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18169
Maintainer: Gabe Black <gabeblack@google.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

python: Enforce absolute imports for Python 3 compatibility

Change-Id: Ia88d7fd472f7aed9b97df81468211384981bf6c6
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/15983
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

python: Make iterator handling Python 3 compatible

Many functions that used to return lists (e.g., dict.items()) now
return iterators and their iterator counterparts (e.g.,
dict.iteritems()) have been removed. Switch calls to the Python 2.7
iterator methods to use the Python 3 equivalent and add explicit list
conversions where necessary.

Change-Id: I0c18114955af8f4932d81fb689a0adb939dafaba
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/15992
Reviewed-by: Juha Jäykkä <juha.jaykka@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>

util: Make dot_writer ignore NULL simobjects.

Also centralize the code which iterates over the parameters of a simnode's
children, and remove a copy/paste block of code in the DVFS block of code.

Change-Id: I01305fbff59346010780ee386ba97ad9106b1f5d
Reviewed-on: https://gem5-review.googlesource.com/4849
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Gabe Black <gabeblack@google.com>

misc: Bail out of DVFS dot if we cannot resolve the domains

This changeset updates the dot output to bail out if it is unable to
resolve the voltage or clock domains (which will cause it to raise an
AttributeError). Additionally, the DVFS dot output is disabled by
default for speed purposes.

Minor fixup for 0aeca8f.

misc: Add secondary dot output for DVFS domains

This patch adds a secondary dot output file which shows the DVFS domains. This
has been done separately for now to avoid cluttering the already existing
diagram. Due to the way that the clock domains are assigned to components in
gem5, this output must be generated after the C++ objects have been
instantiated. This further motivates the need to generate this file separately
to the current dot output, and not to replace it entirely.

mem: Rename Bus to XBar to better reflect its behaviour

This patch changes the name of the Bus classes to XBar to better
reflect the actual timing behaviour. The actual instances in the
config scripts are not renamed, and remain as e.g. iobus or membus.

As part of this renaming, the code has also been clean up slightly,
making use of range-based for loops and tidying up some comments. The
only changes outside the bus/crossbar code is due to the delay
variables in the packet.

misc: Proper type check and import for PortRef

Rewriting the type checking around PortRef, which was interacting strangely
with other Python scripts.

Tested-by: stephan.diestelhorst@arm.com

util: Add ini string as tooltip info in dot output

This patch adds the config ini string as a tooltip that can be
displayed in most browsers rendering the resulting svg. Certain
characters are modified for HTML output.

Tested on chrome and firefox.

util: Add colours to the dot output

This patch is adding a splash of colour to the dot output to make it
easier to distinguish objects of different types. As a bonus, the
pastel-colour palette also makes the output look like a something from
the 21st century.

util: Add class name to dot graph and output to svg

This patch adds the class name to the label, creates some more space
by increasing the rank separation, and additionally outputs the graph
as an editable SVG in addition to the PDF.

base: Add warn() and inform() to m5.utils for use from python

This patch adds two fuctions to m5.util, warn and inform, which mirror those
found in the C++ side of gem5. These are added in addition to the already
existing m5.util.panic and m5.util.fatal which already mirror the C++
functionality. This ensures that warning and information messages generated
by python are in the same format as those generated by C++.

Occurrences of
print "Warning: %s..." % name
have been replaced with
warn("%s...", name)

DOT: improved dot-based system visualization
Revised system visualization to reflect structure and memory hierarchy.
Improved visualization: less congested and cluttered; more colorful.
Nodes reflect components; directed edges reflect dirctional relation, from
a master port to a slave port. Requires pydot.