This patch adds a new matching method for data formatters, in addition
to the existing exact typename and regex-based matching. The new method
allows users to specify the name of a Python callback function that
takes a `SBType` object and decides whether the type is a match or not.

Here is an overview of the changes performed:

- Add a new `eFormatterMatchCallback` matching type, and logic to handle
  it in `TypeMatcher` and `SBTypeNameSpecifier`.

- Extend `FormattersMatchCandidate` instances with a pointer to the
  current `ScriptInterpreter` and the `TypeImpl` corresponding to the
  candidate type, so we can run registered callbacks and pass the type
  to them. All matcher search functions now receive a
  `FormattersMatchCandidate` instead of a type name.

- Add some glue code to ScriptInterpreterPython and the SWIG bindings to
  allow calling a formatter matching callback. Most of this code is
  modeled after the equivalent code for watchpoint callback functions.

- Add an API test for the new callback-based matching feature.

For more context, please check the RFC thread where this feature was
originally discussed:
https://discourse.llvm.org/t/rfc-python-callback-for-data-formatters-type-matching/64204/11

Differential Revision: https://reviews.llvm.org/D135648

- Merge pairs like `eFormatCategoryItemSummary` and
  `eFormatCategoryItemRegexSummary` into a single value. See explanation
  below.

- Rename `eFormatCategoryItemValue` to `eFormatCategoryItemFormat`. This
  makes the enum match the names used elsewhere for formatter kinds
  (format, summary, filter, synth).

- Delete unused values `eFormatCategoryItemValidator` and
  `eFormatCategoryItemRegexValidator`.

This enum is only used to reuse some code in CommandObjectType.cpp.  For
example, instead of having separate implementations for `type summary
delete`, `type format delete`, and so on, there's a single generic
implementation that takes an enum value, and then the specific commands
derive from it and set the right flags for the specific kind of
formatter.

Even though the enum distinguishes between regular and regex matches for
every kind of formatter, this distinction is never used: enum values are
always specified in pairs like
`eFormatCategoryItemSummary | eFormatCategoryItemRegexSummary`.

This causes some ugly code duplication in TypeCategory.cpp. In order to
handle every flag combination some code appears 8 times:

{format, summary, synth, filter} x {exact, regex}

Differential Revision: https://reviews.llvm.org/D134244

Summary:

FormattersContainer.h has two containers: FormatMap and FormattersContainer
itself. FormatMap is essentially just a SetVector with a listener interface that
is aspiring to be thread-safe as most of its functions lock its member mutex.

FormattersContainer is for the most part just calling the matching functions of
internal FormatMap instance and essentially acts as a wrapper class with some
minor formatter search functionality on top. The only difference is that the
FormattersContainer's public `Get` function is actually searching formatters in
the list of formatters (and for example doing regex-matching) while FormatMap's
`Get` function is just looking up a a format by the type matcher string.

This patch deletes `FormatMap` by just renaming it to `FormattersContainer` and
pulling in the two `Get` functions from the original `FormattersContainer`
class.

The only other user of `FormatMap` was the `NamedSummariesMap` in the
`FormatManager` which I migrated by just making it also a `FormattersContainer`
and replaced the only call to the `Get` function (which now has new semantics)
with `GetExact` (which is FormattersContainer's function that has the semantics
of FormatMap's `Get`). As `NamedSummariesMap` only stores non-regex-based
formatters, both `Get` and `GetExact` would have worked, so this was mostly to
clarify that this is supposed to be NFC.

I also added the missing mutex lock in the `GetCount` function which was
previously missing in the `FormatMap` implementation. Technically not "NFC" but
I anyway had to change the function...

Reviewers: labath, mib

Reviewed By: labath

Subscribers: abidh, JDevlieghere

Differential Revision: https://reviews.llvm.org/D84296

This was originally reverted because the m_valid member in TypeMatcher was
unused in builds with disabled asserts. Now the member is gone and the default
constructor is deleted (thanks Eric for the idea!).

Summary:

FormattersContainer stores LLDB's formatters. It's implemented as a templated
map-like data structures that supports any kind of value type and only allows
ConstString and RegularExpression as the key types. The keys are used for
matching type names (e.g., the ConstString key `std::vector` matches the type
with the same name while RegularExpression keys match any type where the
RegularExpression instance matches).

The fact that a single FormattersContainer can only match either by string
comparison or regex matching (depending on the KeyType) causes us to always have
two FormatterContainer instances in all the formatting code. This also leads to
us having every type name matching logic in LLDB twice. For example,
TypeCategory has to implement every method twice (one string matching one, one
regex matching one).

This patch changes FormattersContainer to instead have a single `TypeMatcher`
key that wraps the logic for string-based and regex-based type matching and is
now the only possible KeyType for the FormattersContainer. This means that a
single FormattersContainer can now match types with both regex and string
comparison.

To summarize the changes in this patch:
* Remove all the `*_Impl` methods from `FormattersContainer`
* Instead call the FormatMap functions from `FormattersContainer` with a
  `TypeMatcher` type that does the respective matching.
* Replace `ConstString` with `TypeMatcher` in the few places that directly
  interact with `FormattersContainer`.

I'm working on some follow up patches that I split up because they deserve their
own review:

* Unify FormatMap and FormattersContainer (they are nearly identical now).
* Delete the duplicated half of all the type matching code that can now use one
  interface.
* Propagate TypeMatcher through all the formatter code interfaces instead of
  always offering two functions for everything.

There is one ugly design part that I couldn't get rid of yet and that is that we
have to support getting back the string used to construct a `TypeMatcher` later
on. The reason for this is that LLDB only supports referencing existing type
matchers by just typing their respective input string again (without even
supplying if it's a regex or not).

Reviewers: davide, mib

Reviewed By: mib

Subscribers: mgorny, JDevlieghere

Differential Revision: https://reviews.llvm.org/D84151

as it breaks bots with due to m_valid being an unused class member
except in assert builds.

This reverts commit 074b121642b286afb16adeebda5ec8236f7b8ea9.

This was originally reverted because the Linux bots were red after this landed,
but it seems that was actually caused by a different commit. I double checked
that this works on Linux, so let's reland this on Linux.

Summary:

FormattersContainer stores LLDB's formatters. It's implemented as a templated
map-like data structures that supports any kind of value type and only allows
ConstString and RegularExpression as the key types. The keys are used for
matching type names (e.g., the ConstString key `std::vector` matches the type
with the same name while RegularExpression keys match any type where the
RegularExpression instance matches).

The fact that a single FormattersContainer can only match either by string
comparison or regex matching (depending on the KeyType) causes us to always have
two FormatterContainer instances in all the formatting code. This also leads to
us having every type name matching logic in LLDB twice. For example,
TypeCategory has to implement every method twice (one string matching one, one
regex matching one).

This patch changes FormattersContainer to instead have a single `TypeMatcher`
key that wraps the logic for string-based and regex-based type matching and is
now the only possible KeyType for the FormattersContainer. This means that a
single FormattersContainer can now match types with both regex and string
comparison.

To summarize the changes in this patch:
* Remove all the `*_Impl` methods from `FormattersContainer`
* Instead call the FormatMap functions from `FormattersContainer` with a
  `TypeMatcher` type that does the respective matching.
* Replace `ConstString` with `TypeMatcher` in the few places that directly
  interact with `FormattersContainer`.

I'm working on some follow up patches that I split up because they deserve their
own review:

* Unify FormatMap and FormattersContainer (they are nearly identical now).
* Delete the duplicated half of all the type matching code that can now use one
  interface.
* Propagate TypeMatcher through all the formatter code interfaces instead of
  always offering two functions for everything.

There is one ugly design part that I couldn't get rid of yet and that is that we
have to support getting back the string used to construct a `TypeMatcher` later
on. The reason for this is that LLDB only supports referencing existing type
matchers by just typing their respective input string again (without even
supplying if it's a regex or not).

Reviewers: davide, mib

Reviewed By: mib

Subscribers: mgorny, JDevlieghere

Differential Revision: https://reviews.llvm.org/D84151

This reverts commit 5b0de5756ccc7a540926e4eeaa3b398539d88cd8.

Apparently that caused some test to get stuck on Linuxx. Reverting for now.

Summary:

FormattersContainer stores LLDB's formatters. It's implemented as a templated
map-like data structures that supports any kind of value type and only allows
ConstString and RegularExpression as the key types. The keys are used for
matching type names (e.g., the ConstString key `std::vector` matches the type
with the same name while RegularExpression keys match any type where the
RegularExpression instance matches).

The fact that a single FormattersContainer can only match either by string
comparison or regex matching (depending on the KeyType) causes us to always have
two FormatterContainer instances in all the formatting code. This also leads to
us having every type name matching logic in LLDB twice. For example,
TypeCategory has to implement every method twice (one string matching one, one
regex matching one).

This patch changes FormattersContainer to instead have a single `TypeMatcher`
key that wraps the logic for string-based and regex-based type matching and is
now the only possible KeyType for the FormattersContainer. This means that a
single FormattersContainer can now match types with both regex and string
comparison.

To summarize the changes in this patch:
* Remove all the `*_Impl` methods from `FormattersContainer`
* Instead call the FormatMap functions from `FormattersContainer` with a
  `TypeMatcher` type that does the respective matching.
* Replace `ConstString` with `TypeMatcher` in the few places that directly
  interact with `FormattersContainer`.

I'm working on some follow up patches that I split up because they deserve their
own review:

* Unify FormatMap and FormattersContainer (they are nearly identical now).
* Delete the duplicated half of all the type matching code that can now use one
  interface.
* Propagate TypeMatcher through all the formatter code interfaces instead of
  always offering two functions for everything.

There is one ugly design part that I couldn't get rid of yet and that is that we
have to support getting back the string used to construct a `TypeMatcher` later
on. The reason for this is that LLDB only supports referencing existing type
matchers by just typing their respective input string again (without even
supplying if it's a regex or not).

Reviewers: davide, mib

Reviewed By: mib

Subscribers: mgorny, JDevlieghere

Differential Revision: https://reviews.llvm.org/D84151

Summary:
A *.cpp file header in LLDB (and in LLDB) should like this:
```
//===-- TestUtilities.cpp -------------------------------------------------===//
```
However in LLDB most of our source files have arbitrary changes to this format and
these changes are spreading through LLDB as folks usually just use the existing
source files as templates for their new files (most notably the unnecessary
editor language indicator `-*- C++ -*-` is spreading and in every review
someone is pointing out that this is wrong, resulting in people pointing out that this
is done in the same way in other files).

This patch removes most of these inconsistencies including the editor language indicators,
all the different missing/additional '-' characters, files that center the file name, missing
trailing `===//` (mostly caused by clang-format breaking the line).

Reviewers: aprantl, espindola, jfb, shafik, JDevlieghere

Reviewed By: JDevlieghere

Subscribers: dexonsmith, wuzish, emaste, sdardis, nemanjai, kbarton, MaskRay, atanasyan, arphaman, jfb, abidh, jsji, JDevlieghere, usaxena95, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D73258

This is a half-implemented feature that as far as we can tell was
never used by anything since its original inclusion in 2014. This
patch removes it to make remaining the code easier to understand.

Differential Revision: https://reviews.llvm.org/D71310