Whereas in the past, the user was expected to provide the firtool binary
on the PATH, Chisel will now manage the firtool binary automatically.
Chisel users the following 3-step process for determining which binary
to use:

1. If environment variable FIRTOOL_PATH is set, it will check for
   firtool in that directory
2. It will check the classpath for firtool provided by
   chipsalliance/llvm-firtool
3. It will download a default version of chipsalliance/llvm-firtool

Both (2) and (3) will store the firtool binary in a sensible location
depending on the user's operating system. See dirs-dev/directories-jvm
for more information. The user can override this location by setting the
FIRTOOL_CACHE environment variable.

(cherry picked from commit 3938a465)

# Conflicts:
#	.github/workflows/build-scala-cli-template.yml
#	.github/workflows/ci.yml
#	.github/workflows/test.yml
#	build.sbt
#	build.sc
#	common.sc
#	project/plugins.sbt
#	src/main/scala/circt/stage/phases/CIRCT.scala
#	src/test/scala/chiselTests/LoadMemoryFromFileSpec.scala
#	src/test/scala/circtTests/stage/ChiselStageSpec.scala

* Don't emit nodes when calling .asBool on a Bool

(cherry picked from commit d5e65a33

)

# Conflicts:
#	src/test/scala/chiselTests/LTLSpec.scala
#	src/test/scala/chiselTests/VerificationSpec.scala

* Resolve backport conflicts

---------

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

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

* Add --dump-fir option to ChiselStage (#3453)

This option will dump the .fir before invoking firtool.

Additional changes:
* Use os.lib for invoking firtool
* Use lazy serialization to avoid holding the entire FIRRTL in
  memory.
* Mix NoStackTrace into FirtoolNotFound
* Fix detection of no firtool

(cherry picked from commit 4db86b2f

)

# Conflicts:
#	src/main/scala/circt/stage/CIRCTOptions.scala
#	src/main/scala/circt/stage/ChiselStage.scala
#	src/main/scala/circt/stage/phases/CIRCT.scala

* Resolve backport conflicts

---------

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

Co-authored-by: Jiuyang Liu <liu@jiuyang.me>
Co-authored-by: Megan Wachs <megan@sifive.com>
Co-authored-by: Jack Koenig <koenig@sifive.com>
(cherry picked from commit 3382cab2

)

Co-authored-by: Vladimir Milovanović <barun@eecs.berkeley.edu>

* Add support for configurable warnings (#3414)

Warnings have been assigned unique integers to use as identifiers for
purposes of documentation and configuration.

New CLI option --warn-conf accepts a comma-separated sequence of
<filter>:<action> pairs for customizing warnings.

Supported filters are:
* any          - matches all warnings
* id=<integer> - matches warnings with the integer id
* src=<glob>   - matches warnings where <glob> matches the warning
                 source file

id and src filters can be combined with &.

Supported actions are:
* :s - suppress the warning
* :w - report the warning as a warning (default behavior)
* :e - error on the warning

For example, the new Vec dynamic width matching warning can be
suppressed for source files in src/main/scala while all other warnings
elevated to errors with:
  --warn-conf "id=4&src=src/main/scala/**:s,any:e"

The is also --warn-conf-file which works similarly to --warn-conf except
the <filter>:<action> pairs are newline separated in a file. # is used
for line comments.

(cherry picked from commit 8e33a68b

)

# Conflicts:
#	core/src/main/scala/chisel3/Aggregate.scala
#	core/src/main/scala/chisel3/internal/package.scala
#	src/test/scala/chiselTests/ConstSpec.scala
#	src/test/scala/chiselTests/ProbeSpec.scala

* Resolve backport conflicts and binary compatibility issues

Also make code compile with Scala 2.12

---------

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

* Upgrade mill to 0.11.0 (#3367)

Also add mill to CI.

(cherry picked from commit 1f485a1a

)

# Conflicts:
#	build.sc

* Resolve backport conflicts

---------

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

This fixes Scala compiler warnings in Scala 2.13.12 requiring type
ascriptions on public implicit definitions.

(cherry picked from commit d011b443

)

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

* bug fix for decoderbundle not being able to be lhs op

* add default field for DecodeField for DecodeTable non X case

* add test to show DecodeField default use case

(cherry picked from commit 7466789a

)

Co-authored-by: Jiuyang Liu <liu@jiuyang.me>

(cherry picked from commit e6c07b37

)

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

(cherry picked from commit 1ae807ac

)

Co-authored-by: Mads Rumle Nordstrøm <85681203+madsrumlenordstrom@users.noreply.github.com>

(cherry picked from commit 53a86258

)

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

(cherry picked from commit b904c195

)

Co-authored-by: Jiuyang Liu <liu@jiuyang.me>

(cherry picked from commit 6de7cce4

)

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

* Sanitize Record._elements (#3419)

This moves name sanitation a little earlier and ensures that the
sanitized names are use more consistently throughout Chisel internals.

This fixes a bug in D/I where unsanitary names would lead to a crash.

(cherry picked from commit 5c282db5

)

* Keep Scala 2.12 support by not using VectorMap

* Fix firrtl in tests for older firrtl spec version

---------

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

* SRAM API: Add multiple-clocked port API (#3383)

This PR adds new APIs for the SRAM module to instantiate a number of ports connected to individual clocks. This allows the creation of memories driven by multiple clocks, for use cases like clock domain crossover.

(cherry picked from commit d79ae71e

)

---------

Co-authored-by: Jared Barocsi <82000041+jared-barocsi@users.noreply.github.com>
Co-authored-by: Jared Barocsi <jared.barocsi@sifive.com>

[svsim] Don't redirect simulation stderr to a pipe (#3403)

(cherry picked from commit e51fa08c

)

Co-authored-by: George Lyon <GeorgeLyon@users.noreply.github.com>

* Deprecate calling .viewAs on non-hardware (#3395)

It's an error in most cases already, and in the cases it isn't, make it
a warning. Also fix a crash that could occur when viewing a non-Data
containing non-hardware Data.

(cherry picked from commit 1e524de9

)

# Conflicts:
#	src/test/scala/chiselTests/experimental/DataView.scala

* Resolve backport conflicts

---------

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

This is not a functional bug. The recursive form of reify for Element
would use the .topBinding from the wrong argument, so it would recurse
an extra time, but it would ultimately converge to the right value.

(cherry picked from commit 374b45b9

)

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

* Support literals and DontCare in DataView targets (#3389)

(cherry picked from commit 0f803cd8

)

# Conflicts:
#	src/test/scala/chiselTests/experimental/DataView.scala

* Resolve backport conflicts

---------

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

* log2 functions
* unsignedBitLength

(cherry picked from commit 88fecfc1

)

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

(cherry picked from commit 2e95804f

)

Co-authored-by: Jared Barocsi <82000041+jared-barocsi@users.noreply.github.com>

Co-authored-by: Jiuyang Liu <liu@jiuyang.me>
Co-authored-by: Jack Koenig <koenig@sifive.com>
(cherry picked from commit 8851faed

)

Co-authored-by: Jared Barocsi <82000041+jared-barocsi@users.noreply.github.com>

(cherry picked from commit b910bf94

)

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

* Allow IntrinsicModule to be used in Instantiate

Change a few `RawModule`s to `BaseModule`s to allow for intrinsic
modules to be used with the instantiation API.

* Add tests for Instantiate of non-RawModules

---------

Co-authored-by: Fabian Schuiki <fabian@schuiki.ch>
(cherry picked from commit 951f8b7c

)

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

(cherry picked from commit e718aac1

)

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

(cherry picked from commit c81c9f18

)

Co-authored-by: Megan Wachs <megan@sifive.com>

(cherry picked from commit b83f3695

)

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

(cherry picked from commit 308eb6a4

)

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

(cherry picked from commit 6e8eee88

)

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

This enables Chisel users to use these newer Scala versions.

(cherry picked from commit b22c3ba2

)

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

(cherry picked from commit e20a0380

)

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

* Make svsim shutdown gracefully when the test throws an exception (#3309)

(cherry picked from commit 36a2ddff

)

* Waive false binary compatibility failure

The constructor is package private so user code cannot observe this
change.

---------

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

(cherry picked from commit 9e392013

)

Co-authored-by: Jared Barocsi <82000041+jared-barocsi@users.noreply.github.com>

(cherry picked from commit 1697f39f

)

Co-authored-by: Daniel Resnick <danielzresnick@gmail.com>

The updated versions fix warnings about deprecated actions.

(cherry picked from commit 21d8f6b7

)

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

Co-authored-by: jackkoenig <jackkoenig@users.noreply.github.com>

* Optimize BitPat equals, overlap, and cover (#3285)

(cherry picked from commit f590ac9f

)

* Fix binary compatibility issue

---------

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

* Add Top-level parameterized reset type
* Add the ability to set the top reset type for any Module

(cherry picked from commit 5406b4d5

)

Co-authored-by: Megan Wachs <megan@sifive.com>