Fixes #893

- Add Chisel logo PNG and SVG to repo

Use reusable executors and reusable commands.

Add CircleCI status badge to README

Resolves #917

Be consistent with the use of /dev/null for sbt's stdin (force sbt to exit instead of bringing up a dialog).
Enforce Jenkins' scalastyle limit of 40 warnings via CHECKSTYLE_LIMIT in environment.
Force tests to run sequentially if -DminimalResources is set on the command line.
Ensure we see valid scalastyle output.
Make checkstyle dependent on one of the tests (so a style failure will fail the build only after tests pass).

* Turned off strong enum annotations because they weren't working
  with Vec indexes
* Ignore annotation tests using ScalaTest's 'ignore', rather than
  by commenting them out

Quickfix for LoadMemoryTransform that gets this to work with Instance
Annotations. The new Instance Annotations caused a corner case where a
LoadMemoryAnnotation would be duplicated (via update/renaming) and the
resulting annotation would differ from the original in only their
originalMemoryNameOpt field. This corrects that by having the
ChiselLoadMemoryAnnotation also emit the originalMemoryNameOpt field where
it did not previously.

First part of a fix for freechipsproject/firrtl#922.

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>

Make BaseModule.name lazy

This wraps the evaluation of BaseModule.name in try/catch to look for a
NullPointerException that may result from trying to evaluate desiredName
before it's ready. This catches a test case of using a desiredName that
depends on a later defined eager subinstance.

h/t @jackkoenig

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>

This changes BaseModule.name to be lazy (instead of eager) to enable a
desiredName to be a function of a sub-instance. This includes a test case
showing the new behavior.

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>

* Added new strongly-typed enum construct called "StrongEnum". "StrongEnum" will automatically generate annotations that HDL backends can use to mark components as enums

Removed "override val width" constructor parameter from "Element" so that classes with variable widths, like the new strong enums, can inherit from it

Changed the parameter types of certain functions, such as "switch", "is", and "LitArg.bindLitArg" from "Bits" to "Element", so that they can take the new strong enums as arguments

* Added tests for the new strong enums

* Changed StrongEnum exception names and made sure in StrongEnum tests that the correct types of exceptions are thrown

* Fixed bug where an enum's global annotation would not be set if it was used in multiple circuits

Made styling changes to StrongEnum.scala

* Reverted accidental changes to the AnnotatingDiamond test

* Changed the API for casting non-literal UInts to enums

Added an isValid function that checks whether or not enums have valid values

Calling getWidth on an enum's companion object now returns a BigInt instead of an Int

* Casting a literal to an enum using the StrongEnum.castFromNonLit(n) function is now simply a wrapper for StrongEnum.apply(n)

* Fixed compilation bug

* * Added "next" method to EnumType
* Renamed "castFromNonLit" to "fromBits"

* The FSM example in the test/scala/cookbook now uses StrongEnums

* * Changed strong enum API, so that users no longer have to declare both a class and a companion object for each strong enum

* Strong enums do not have to be static any longer

* * Added scope protections to ChiselEnum.Value so that users cannot call it
outside of a ChiselEnum definition

* Renamed ChiselEnum.Value type to ChiselEnum.Type so that we can give
it a companion object just like UInt and Bool do

* * Moved strong enums into experimental package
* Non-literal UInts can now be cast to enums with apply() rather than
fromBits()
* Reduced code-duplication by moving some functions from EnumType and
Bits to Element

* Drop pomExtra scm definitions (now generated by git.remoteRepo.

* Incorporate lessons learned from latest publishing.

Change InlineSpec to expect "_" and not "$"

A FIRRTL change to inlining changes the inlined instance delimiter to "_"
from "$". This change is reflected here in an update to the associated
Chisel tests for the Inline API.

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>

* Modify noenq to set the input wires to DontCare.

- Add dumpAnnotations method to Driver

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>

The litOption field currently has no type that can be inferred. Some
subtypes override it and give it a type, but the original declaration
should have a type so things like bundles can override it.

API Documentation Improvements

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>

Minor updates to Element's documentation to conform with ScalaDoc style.

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>

Adds documentation of Arithmetic, Bitwise, and Comparison operators for
SInt.

The duplication of documentation between UInt and SInt strongly indicate a
unification around Num would make sense.

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>

This adds documentation of Arithmetic, Comparison, and Bitwise operator
methods of UInt.

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>

This includes general documentation for the arithmetic and comparison
operators of Num.

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>

This puts Data's connection methods, `:=` and `<>`, in the ScalaDoc
`Connect` group. These groups will propagate through to all children of
Data, e.g., UInt, and cause those methods to be grouped in the ScalaDoc of
these children.

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>

This places all do_* methods (and two unary methods in SInt and FixedPoint
that act like do_* methods) inside the ScalaDoc group
"SourceInfoTransformMacro". Classes/objects which need information about
this group have an additional bare trait mixed in, `SourceInfoDoc`, that
provides information about the group and its priority.

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>

This adds the `-groups` option to `scalacOptions`. This makes ScalaDoc
build with group support such that developers can group methods using the
`@group <groupName>` tag.

This also adds the `-skip-packages chisel3.internal` option. This makes
ScalaDoc build while ignoring everything in the chisel3.internal package.

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>