* firrtl: add optional statement labels for stop, printf, assert, assume and cover

* test: parsing of statement labels

* ir: ensure that name is properly retained

* SymbolTable: add support for labled statements

* test: parsing statement labels

* test: lower types name collisions with named statements

* ignore empty names

* Inline: deal with named and unnamed statements

* RemoveWires: treat stop, printf and verification statements as "others"

* test: fix InlineInstance tests

* DeadCodeEliminations: statements are now als declarations

* CheckHighForm: ensure that statement names are not used as references

* CheckSpec: throw error if statement name collides

* add pass to automatically add missing statement names

* check: make sure that two statements cannot have the same name

* stmtLabel -> stmtName

* scalafmt

* add statement names to spec

* spec: meta data -> metadata

* EnsureStatementNames: explain naming algorithm

* remove returns

* better namespace use

* ir: add CanBeReferenced trait

* ir: add newline as jack requested

Add "Must Deduplicate" API

This enables marking modules as "must deduplicate". If modules marked as
such do not deduplicate, the transform will create error reports and
make suggestions as to why deduplication failed.

* New factory method enables direct construction of DiGraphs from edges
* DiGraph.prettyTree enables visualization of tree or multi-tree
  diagraphs

Signed-off-by: Jean Bruant <jean.bruant@ovhcloud.com>

* build: add data-class dependency
* ir: turn Print, Stop and Verification nodes into data classes

This is in preparation to add a name field to them.

Co-authored-by: Jack Koenig <jack.koenig3@gmail.com>

* Add SubAccess case to Utils.splitRef

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

* Update Utils.splitRef to use IR types

Change Utils.splitRef to use the actual IR types instead of their
WIR aliases. Update the Scaladoc note to reflect this.

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

Co-authored-by: Jack Koenig <koenig@sifive.com>

* Deprecate firrtl.passes.ToWorkingIR

Deprecate ToWorkingIR as it is now an identity transform.

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

* Deprecate firrtl.stage.Forms.WorkingIR

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

* Switch from Forms.WorkingIR to Forms.MinimalHighForm

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

Co-authored-by: Jack Koenig <koenig@sifive.com>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

This allows ConstantPropagation to be used in cases where
ValidIfs need to be maintained, e.g., in the formal backend.

Co-authored-by: Adam Izraelevitz <adam.izraelevitz@sifive.com>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

Fixes bug with mul or div followed by cat.
Also fixes some Verilog lint issues.

* Check Unidoc on all versions of Scala

  It is required for publishing and we publish every version

* Fix conflicting cross-version suffixes issue

  When running `sbt ++2.13.4 unidoc`, SBT would set the Scala version
  for the fuzzer and benchmark projects even though they aren't really
  relevant to the command. This may be a misconfiguration or a bug in
  the unidoc plugin. Whatever the case, simply making it possible for
  them to use the same version of Scala as the firrtl project (on which
  they depend) fixes the issue.

* Match versions of Scala in build.sbt and CI

* Fix unidoc issues in 2.13.4

  There is some bug in ScalaDoc not finding some links in firrtl.options
  so those links were made absolute as a workaround.

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

This adds a --dont-fold options (backed by a DisableFold annotation)
that lets a user specify primitive operations which should never be
folded. This feature lets a user disable certain folds which may be
allowable in FIRRTL (or by any sane synthesis tool), but due to inane
Verilog language design causes formal equivalence tools to fail due to
the fold.

Add a test that a user can disable `a / a -> 1` with a
DisableFold(PrimOps.Div) annotation.

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

Fix scalafmtCheckAll failures that snuck through

* Fix .run_formal_checks for Github Actions instead of Travis
* Remove .run_chisel_tests

Because we publish SNAPSHOTs on every merge to master, the Chisel repo
checks against master of FIRRTL regularly

* Only run unidoc for Scala 2.12

Under Travis we ran for 2.11, 2.12, and 2.13, but it doesn't work when
using ++2.<major>.<minor> when major != to 2.12. It seems if we want to
run all 3, we have to run as `sbt +unidoc`. It's not clear how much
benefit we get from building on the other versions, so stick with 2.12
for now.

* Generate .mergify.yml with script in chisel-repo-tools

Generated with config:

conditions:
  - status-success=all tests passed
branches:
  - 1.2.x
  - 1.3.x
  - 1.4.x

This is done by having LowerTypes uses two RenameMaps instead of one for
each module. There is one for renaming instance paths, and one for
renaming everything within modules.

Also add some utilities:
* TargetUtils for dealing with InstanceTargets
* RenameMap.fromInstanceRenames

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

This is now set by sbt-ci-release

sbt-ci-release changes the commands required to publish to Sonatype.
While this may be a desirable change at some point, it is inconsistent
with other repos. Reverting for the time being.

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

* add test for RemoveAccessesSpec.

* fix nested SubAccess bug.

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

* Add SortModules to transform to def-before-use

Adds a new transform, SortModules, that transforms a FIRRTL circuit
to enforce an invariant of modules and external modules being defined
before use. This transform is left as optional in the event that a
user may wish to have a quick way of getting the circuit to respect
this property as may be expected of some other tool, e.g., MLIR.

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

* Add test of SortModules transform

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

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

Verilator 4.034 was complaining about wires being named weak and strong
because those are SV 2009 keywords.  Added them to the Utils.v_keywords list

* Make MultiTargetAnnotation.targets a def

This enables the annotation writer to choose their own underlying data structure

* Update MultiTargetAnnotation ScalaDoc

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

Seq[(Int, DoPrimGen)] to Map[ExprGen[_ <: Expression], Int]

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

Uses sbt-ci-release for automation

It would replace them with a validif node with a UIntLiteral which can
lead to type errors.

* smt: add test for write port collision

* smt: add missing call to insertDummyAssignsForMemoryOutputs

* smt: fix typo in write port code

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>