Also delete an errant println in InstanceSpec

Chisel <> semantics differ somewhat from FIRRTL <= semantics,
so we only emit <= when it would be legal. Otherwise we continue
the old behavior of emitting a connection for every leaf-level
Element.

Co-authored-by: Deborah Soung <debs@sifive.com>
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>

* Tweaks to the Verilog-vs-Chisel Page

* Update cookbook.md

* Update verilog-vs-chisel.md

* Update verilog-vs-chisel.md

* Issue errors on out-of-range extracts when width is known

Firrtl will catch this later on, but better to error early if possible.

* Test that errors are generated on OOB extracts when width is known

Co-authored-by: Shola Ogunkelu @Shorla
Co-authored-by: Megan Wachs <megan@sifive.com>
Co-authored-by: Deborah Soung <debs@sifive.com>

Completed as part of Outreachy Internship Dec 2021-March 2022.

Widths are now padded to the maximum width of the inputs.

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

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

* Only call _elementsImpl once in Bundle.elements

* Distinguish compiler plugin and reflective _elementsImpl

Bundle.elements now will only do post-processing if the user is using
plugin-generated _elementsImpl. This improves performance for the case
where the user does not opt-in to using the plugin to generate
_elementsImpl.

* Change type of Bundle._elementsImpl to Iterable

It was previously SeqMap (ListMap on Scala 2.12). This change gives us
more freedom to optimize the implementation without breaking binary
compatibility. It is scala.collection.Iterable because it is perfectly
fine to return mutable collections (like Arrays) since the only use is
to Iterate on them.

* Disallow users implementing Bundle._elementsImpl

Currently, it would result in a runtime linkage error. This turns it
into a compile-time error.

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

Use Builder.deprecated instead of Builder.warning so that the warnings
are aggregated by source locator to prevent spamming the screen with
duplicated warnings.

Warn if clock at memory instantiation differs from clock bound at port
creation and port clock is not manually passed

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

Adds generation of `Bundle.elements` method to the chores done by the compiler plugin
For each `Bundle` find the relevant visible Chisel field members and construct a
hard-coded list of the elements and their names implemented as `_elementsImpl`

For more details: See plugins/README.md

- Should be no change in API
- Handles inheritance and mixins
- Handles Seq[Data]
- Tests in BundleElementSpec

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

* Do not trim stack traces of exceptions with no stack trace

This prevents us from accidentally giving stack traces to exceptions
that don't have them and giving misleading messages telling users to use
--full-stacktrace when it won't actually do anything.

Also deprecate ChiselException.chiselStackTrace which is no longer being
used anywhere in this codebase.

* Add exception class for multiple-errors reported

New chisel3.internal.Errors replaces old anonymous class that would show
up as chisel3.internal.ErrorLog$$anon$1 in error messages.

* Add new option --throw-on-first-error

This tells Chisel not to aggregate recoverable errors but instead to
throw an exception on the first one. This gives a stack trace for users
who need it for debugging.

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

This reverts commit 4097d179

.

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

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

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

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

* Fix the QMC bug for constant and dontcare output.
* Fix the Espresso bug for constant and dontcare output.

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

The new reflection based IO autowrapping for compatibility mode Modules
would previously throw a NullPointerExceptions if any hardware were
constructed in the Module before "val io" was initialized. The logic is
now more robust for this case.

Co-authored-by: Schuyler Eldridge <schuyler.eldridge@sifive.com>

#naming implies within the current file. Removing the # refers to a file in the current directory.

This only includes a merge-based flow which will presumably be
squash-and-merged for any merged PRs. It is possible to do this with
rebasing but it is tricky and hard to describe in a fool-proof way.

Bump to 3.6-SNAPSHOT