path: root/release-notes/OTP-27.0-rc1.README.txt

Inital Release:          OTP 27.0
Git Tag:                 OTP-27.0
Date:                    2024-02-14
Trouble Report Id:       OTP-16607, OTP-18568, OTP-18577, OTP-18589,
                         OTP-18590, OTP-18594, OTP-18606, OTP-18608,
                         OTP-18609, OTP-18622, OTP-18639, OTP-18641,
                         OTP-18642, OTP-18648, OTP-18658, OTP-18667,
                         OTP-18668, OTP-18671, OTP-18673, OTP-18680,
                         OTP-18682, OTP-18684, OTP-18699, OTP-18703,
                         OTP-18709, OTP-18713, OTP-18714, OTP-18715,
                         OTP-18716, OTP-18717, OTP-18727, OTP-18741,
                         OTP-18742, OTP-18743, OTP-18744, OTP-18750,
                         OTP-18756, OTP-18761, OTP-18766, OTP-18774,
                         OTP-18778, OTP-18779, OTP-18781, OTP-18783,
                         OTP-18784, OTP-18785, OTP-18786, OTP-18787,
                         OTP-18788, OTP-18789, OTP-18793, OTP-18794,
                         OTP-18795, OTP-18796, OTP-18801, OTP-18804,
                         OTP-18805, OTP-18806, OTP-18807, OTP-18808,
                         OTP-18809, OTP-18813, OTP-18816, OTP-18819,
                         OTP-18820, OTP-18825, OTP-18831, OTP-18834,
                         OTP-18835, OTP-18846, OTP-18847, OTP-18848,
                         OTP-18849, OTP-18852, OTP-18856, OTP-18859,
                         OTP-18860, OTP-18865, OTP-18870, OTP-18874,
                         OTP-18875, OTP-18876, OTP-18878, OTP-18879,
                         OTP-18881, OTP-18887, OTP-18892, OTP-18894,
                         OTP-18898, OTP-18904, OTP-18908, OTP-18912,
                         OTP-18913, OTP-18914, OTP-18916, OTP-18918,
                         OTP-18920, OTP-18922, OTP-18923, OTP-18927,
                         OTP-18928, OTP-18929, OTP-18930, OTP-18934,
                         OTP-18941, OTP-18942, OTP-18944, OTP-18945,
                         OTP-18946, OTP-18947, OTP-18950, OTP-18951,
                         OTP-18954, OTP-18955, OTP-18959, OTP-18961,
                         OTP-18963, OTP-18967, OTP-18972, OTP-18973,
                         OTP-18976, OTP-18977, OTP-18978, OTP-18980
Seq num:                 #312, 7809, BL-322, ERIERL-43, ERIERL-964,
                         ERIERL-967, ERIERL-985, GH-4992, GH-6152,
                         GH-6692, GH-6985, GH-7183, GH-7232, GH-7266,
                         GH-7295, GH-7397, GH-7432, GH-7493, GH-7494,
                         GH-7706, GH-7718, GH-8061, OTP-16448,
                         OTP-16608, OTP-16875, OTP-17734, OTP-18746,
                         OTP-18750, PR-6510, PR-6639, PR-6791,
                         PR-6985, PR-7110, PR-7125, PR-7174, PR-7202,
                         PR-7220, PR-7236, PR-7243, PR-7267, PR-7274,
                         PR-7299, PR-7313, PR-7316, PR-7348, PR-7380,
                         PR-7383, PR-7388, PR-7398, PR-7419, PR-7428,
                         PR-7441, PR-7443, PR-7451, PR-7465, PR-7470,
                         PR-7474, PR-7475, PR-7481, PR-7491, PR-7496,
                         PR-7528, PR-7534, PR-7535, PR-7538, PR-7556,
                         PR-7585, PR-7590, PR-7592, PR-7607, PR-7628,
                         PR-7639, PR-7649, PR-7651, PR-7675, PR-7684,
                         PR-7697, PR-7699, PR-7700, PR-7701, PR-7702,
                         PR-7703, PR-7711, PR-7720, PR-7726, PR-7728,
                         PR-7732, PR-7738, PR-7739, PR-7740, PR-7745,
                         PR-7779, PR-7781, PR-7782, PR-7790, PR-7809,
                         PR-7816, PR-7824, PR-7844, PR-7845, PR-7846,
                         PR-7847, PR-7856, PR-7857, PR-7869, PR-7879,
                         PR-7891, PR-7898, PR-7917, PR-7918, PR-7936,
                         PR-7942, PR-7952, PR-7957, PR-7960, PR-7963,
                         PR-7973, PR-7981, PR-7993, PR-8003, PR-8004,
                         PR-8006, PR-8026, PR-8042, PR-8063, PR-8067,
                         PR-8069, PR-8076, PR-8086, PR-8090, PR-8092
System:                  OTP
Release:                 27
Application:             asn1-5.3, common_test-1.27, compiler-8.5,
                         crypto-5.5, debugger-5.4, dialyzer-5.2,
                         diameter-2.4, edoc-1.3, eldap-1.3,
                         erl_interface-5.6, erts-14.3, et-1.8,
                         eunit-2.10, ftp-1.3, inets-9.2,
                         jinterface-1.15, kernel-9.3, megaco-4.6,
                         mnesia-4.24, observer-2.16, odbc-2.15,
                         os_mon-2.10, parsetools-2.6, public_key-1.16,
                         reltool-1.1, runtime_tools-2.1, sasl-4.3,
                         snmp-5.16, ssh-5.2, ssl-11.2, stdlib-6.0,
                         syntax_tools-3.2, tftp-1.2, tools-4.0,
                         wx-2.5, xmerl-1.4
Predecessor:             OTP

Check out the git tag OTP-27.0, and build a full OTP system including
documentation.

# HIGHLIGHTS

- The functions `is_equal/2`, `map/2`, and `filtermap/2` have been added to the
  modules `sets`, `ordsets`, and `gb_sets`.

  Own Id: OTP-18622
  Related Id(s): GH-7183, GH-7232

- The compiler now emits nicer error message for function head mismatches. For
  example, given:

      a() -> ok;
      a(_) -> error.

  Erlang/OTP 26 and earlier would emit a diagnostic similar to:

      t.erl:6:1: head mismatch
      %    6| a(_) -> error.
      %     | ^

  while in Erlang/OTP 27 the diagnostic is similar to:

      t.erl:6:1: head mismatch: function a with arities 0 and 1 is regarded as two distinct functions. Is the number of arguments incorrect or is the semicolon in a/0 unwanted?
      %    6| a(_) -> error.
      %     | ^

  Own Id: OTP-18648
  Related Id(s): PR-7383

- The compiler will now merge consecutive updates of the same record.

  As an example, the body of the following function will be combined into a
  single tuple creation instruction:

      -record(r, {a,b,c,d}).

      update(Value) ->
          R0 = #r{},
          R1 = R0#r{a=Value},
          R2 = R1#r{b=2},
          R2#r{c=3}.

  Own Id: OTP-18680
  Related Id(s): ERIERL-967, PR-7491, PR-8086

- As announced in OTP 26.1, `0.0` is no longer considered equivalent to `-0.0`
  when using the term equivalence operators (`=:=` and `=/=`).

  The arithmetic equality operators (`==` and `/=`) and all relative
  comparison operations still consider `0.0` equal to `-0.0`.

  Own Id: OTP-18717
  Related Id(s): PR-7728

  *** POTENTIAL INCOMPATIBILITY ***

- The `erl` command now supports the `-S` flag, which is similar to the `-run`
  flag, except that it will pass all arguments up to end of the command line to
  the called function. (The `-run` flag will not pass arguments beginning with a
  hyphen.) Another difference is that `-S` will always call a function with one
  argument, passing an empty list if no arguments were given.

  Own Id: OTP-18744
  Related Id(s): PR-7470

- Triple-Quoted Strings has been implemented as per EEP 64. See String in the
  Reference Manual.

  Example:

      1> """
         a
         b
         c
         """.
      "a\nb\nc"

  Adjacent string literals without intervening white space is now a syntax
  error, to avoid possible confusion with triple-quoted strings. For example:

      1> "abc""xyz".
      "xyz".
      * 1:6: adjacent string literals without intervening white space

  Own Id: OTP-18750
  Related Id(s): PR-7313, PR-7451, OTP-18746

  *** POTENTIAL INCOMPATIBILITY ***

- Several new functions that accept funs have been added to module `timer`.

  Functions `apply_after/2`, `apply_interval/2`, and `apply_repeatedly/2` accept
  a 0-ary fun as the second argument, while functions `apply_after/3`,
  `apply_interval/3`, and `apply_repeatedly/3` accept an n-ary fun as the second
  and a list of n arguments for the fun as the third argument.

  Own Id: OTP-18808
  Related Id(s): PR-7649

- Sigils on string literals have been implemented as per EEP 66, that is:
  binary and string sigils in verbatim and escape characters variants, as well
  as a default (vanilla) Sigil. All for ordinary strings and for triple-quoted
  strings (EEP 64). See Sigils in the Reference Manual.

  Examples:

      1> ~"Björn".
      <<"Björn"/utf8>>
      2> ~b"Björn".
      <<"Björn"/utf8>>
      3> ~S"\s*(\w+)".
      "\\s*(\\w+)"
      4> ~B"\s*(\w+)".
      <<"\\s*(\\w+)">>

  Own Id: OTP-18825
  Related Id(s): PR-7684, OTP-18750

- Native coverage support has been implemented in the JIT. It will automatically
  be used by the `cover` tool to reduce the execution overhead when running
  cover-compiled code.

  There are also new APIs to support native coverage without using the `cover`
  tool.

  To instrument code for native coverage it must be compiled with the
  `line_coverage` option.

  To enable native coverage in the runtime system, start it like so:

      $ erl +JPcover true

  There are also the following new functions for supporting native coverage:

  - code:coverage_support/0
  - code:get_coverage/2
  - code:reset_coverage/1
  - code:get_coverage_mode/0
  - code:get_coverage_mode/1
  - code:set_coverage_mode/1

  Own Id: OTP-18856
  Related Id(s): PR-7856

- EEP-59 - Documentation Attributes has been implemented.

  Documentation attributes can be used to document functions, types, callbacks,
  and modules. The keyword `-moduledoc "Documentation here".` is used to
  document modules, while `-doc "Documentation here".` can be used on top of
  functions, types, and callbacks to document them, respectively.

  - Types, callbacks, and function documentation can be set to `hidden` either
    via `-doc false` or `-doc hidden`. When documentation attributes mark a type
    as hidden, they will not be part of the documentation.
  - The documentation from `moduledoc` and `doc` gets added by default to the
    binary beam file, following the format of EEP-48.
  - Using the compiler flag `warn_missing_doc` will raise a warning when doc.
    attributes are missing in exported functions, types, and callbacks.
  - `moduledoc`s and `doc`s may refer to external files to be embedded, such as
    `-doc {file, "README.md"}.`, which refers to the file `README.md` found in
    the current working directory.
  - The compiler warns about exported functions whose specs refer to hidden
    types. Thus, there will be warnings when a hidden type (meaning, the type is
    not part of the documentation) gets used in an exported function.

  Own Id: OTP-18916
  Related Id(s): PR-7936

- New `ets` functions ets:first_lookup/1, ets:next_lookup/2,
  ets:prev_lookup/2 and ets:last_lookup/1. Example: ets:next_lookup/1 is
  equivalent to ets:next/2 followed by ets:lookup/2 with the next key. The
  new combined functions are more efficient and with guaranteed atomicity.

  Own Id: OTP-18923
  Related Id(s): PR-6791

- The `maybe` expression is now enabled by default.

  To use `maybe` as an atom, it needs to be single-quoted. Alternatively, the
  `maybe` expression can be disabled by disabling the `maybe_expr` feature. That
  can be done by placing the following the line at the beginning of an Erlang
  source file:

      -feature(maybe_expr, disable).

  Another way to disable the `maybe_expr` feature is by passing the
  `-disable-feature` option to `erlc`:

      erlc -disable-feature maybe_expr some_file.erl

  Own Id: OTP-18944
  Related Id(s): PR-8067

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

- Safe destructive update of tuples has been implemented in the compiler and
  runtime system. This allows the VM to update tuples in-place when it is safe
  to do so, thus improving performance by doing less copying but also by
  producing less garbage.

  Example:

      -record(rec, {a,b,c}).

      update(#rec{a=needs_update,b=N}=R0) ->
          R = R0#rec{a=up_to_date},
          if
              N < 0 ->
                  R#rec{c=negative};
              N == 0 ->
                  R#rec{c=zero};
              N > 0 ->
                  R#rec{c=positive}
          end.

  The record updates in each of the three clauses of the `if` can safely be done
  in-place, because variable `R` is not used again.

  Own Id: OTP-18972
  Related Id(s): PR-8090

- Multiple trace sessions.

  Own Id: OTP-18980

# POTENTIAL INCOMPATIBILITIES

- The `pid` field has been removed from `erlang:fun_info/1,2`.

  Own Id: OTP-18594
  Related Id(s): PR-7274

- By default, escripts will now be compiled instead of interpreted. That means
  that the `compiler` application must be installed.

  Own Id: OTP-18639
  Related Id(s): PR-7348

- Introduce default value for httpd_server name configuration to improve ease of
  use.

  Own Id: OTP-18641
  Related Id(s): PR-7316

- As announced in OTP 26.1, `0.0` is no longer considered equivalent to `-0.0`
  when using the term equivalence operators (`=:=` and `=/=`).

  The arithmetic equality operators (`==` and <c>/=</c>) and all relative
  comparison operations still consider `0.0` equal to `-0.0`.

  Own Id: OTP-18717
  Related Id(s): PR-7728

  *** HIGHLIGHT ***

- Triple-Quoted Strings has been implemented as per EEP 64. See String in the
  Reference Manual.

  Example:

      1> """
         a
         b
         c
         """.
      "a\nb\nc"

  Adjacent string literals without intervening white space is now a syntax
  error, to avoid possible confusion with triple-quoted strings. For example:

      1> "abc""xyz".
      "xyz".
      * 1:6: adjacent string literals without intervening white space

  Own Id: OTP-18750
  Related Id(s): PR-7313, PR-7451, OTP-18746

  *** HIGHLIGHT ***

- The documentation for the preprocessor now mentions that `defined(Name)` can
  be called in the condition for an `-if` or `-elif` directive to test whether
  `Name` is the name of a defined macro. (This feature was implemented in OTP
  21.)

  If a function call in an `-if` or `-elif` with a name that is not the name of
  a guard BIF, there would not be a compilation error, but would instead cause
  the lines following the directive to be skipped. This has now been changed to
  be a compilation error.

  Own Id: OTP-18784
  Related Id(s): GH-7706, PR-7726

# OTP-27.0

## Fixed Bugs and Malfunctions

- As announced in OTP 26.1, `0.0` is no longer considered equivalent to `-0.0`
  when using the term equivalence operators (`=:=` and `=/=`).

  The arithmetic equality operators (`==` and <c>/=</c>) and all relative
  comparison operations still consider `0.0` equal to `-0.0`.

  Own Id: OTP-18717
  Related Id(s): PR-7728

  *** HIGHLIGHT ***

  *** POTENTIAL INCOMPATIBILITY ***

- The documentation for the preprocessor now mentions that `defined(Name)` can
  be called in the condition for an `-if` or `-elif` directive to test whether
  `Name` is the name of a defined macro. (This feature was implemented in OTP
  21.)

  If a function call in an `-if` or `-elif` with a name that is not the name of
  a guard BIF, there would not be a compilation error, but would instead cause
  the lines following the directive to be skipped. This has now been changed to
  be a compilation error.

  Own Id: OTP-18784
  Related Id(s): GH-7706, PR-7726

  *** POTENTIAL INCOMPATIBILITY ***

## Improvements and New Features

- The `maybe` expression is now enabled by default.

  To use `maybe` as an atom, it needs to be single-quoted. Alternatively, the
  `maybe` expression can be disabled by disabling the `maybe_expr` feature. That
  can be done by placing the following the line at the beginning of an Erlang
  source file:

      -feature(maybe_expr, disable).

  Another way to disable the `maybe_expr` feature is by passing the
  `-disable-feature` option to `erlc`:

      erlc -disable-feature maybe_expr some_file.erl

  Own Id: OTP-18944
  Related Id(s): PR-8067

  *** HIGHLIGHT ***

# asn1-5.3

## Fixed Bugs and Malfunctions

- Multiple bugs has been eliminated in the specialized decode feature.

  Own Id: OTP-18813
  Related Id(s): PR-7790

## Improvements and New Features

- Specs have been added to all `asn1ct` API functions.

  Own Id: OTP-18804
  Related Id(s): PR-7738

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

> #### Full runtime dependencies of asn1-5.3
>
> erts-14.0, kernel-9.0, stdlib-5.0

# common_test-1.27

## Improvements and New Features

- Calls to ct:capture_start/0 and ct:capture_stop/0 are now synchronous to
  ensure that all output is captured.

  Own Id: OTP-18658
  Related Id(s): PR-7380

- The order in which multiple hooks are executed can now be reversed after each
  config function. See CTH Execution Order.

  Own Id: OTP-18682
  Related Id(s): ERIERL-43, GH-7397, PR-7496

- The default CSS will now include a basic dark mode handling if it is preferred
  by the browser.

  Own Id: OTP-18761
  Related Id(s): PR-7428

- `-callback` attributes have been added to `ct_suite` and `ct_hooks`.

  Own Id: OTP-18781
  Related Id(s): PR-7701

- The built-in cth_log_redirect hook can now be configured to replace default
  logger reports in terminal with HTML logs.

  Own Id: OTP-18875
  Related Id(s): PR-7891

- Error handling for the `ct_property_test` framework has been enhanced.

  Own Id: OTP-18881
  Related Id(s): PR-7824

- Enhance test case documentation, making it clear how a test case can be
  failed.

  Own Id: OTP-18892
  Related Id(s): PR-7869

- The failing line in the test source code is now colored to make it easier to
  find on the screen.

  Own Id: OTP-18898
  Related Id(s): PR-7917

- Function specifications and types have been added to all public API functions.

  Own Id: OTP-18913

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

> #### Full runtime dependencies of common_test-1.27
>
> compiler-6.0, crypto-4.5, debugger-4.1, erts-7.0, ftp-1.0, inets-6.0,
> kernel-8.4, observer-2.1, runtime_tools-1.8.16, sasl-2.5, snmp-5.1.2, ssh-4.0,
> stdlib-4.0, syntax_tools-1.7, tools-3.2, xmerl-1.3.8

# compiler-8.5

## Fixed Bugs and Malfunctions

- Generators for binary comprehensions could be evaluated before it was known
  that they would be needed. That could result in a binary comprehensions
  failing if a generator that should not be evaluated until later failed.

  As an example, consider this module:

      -module(t).
      -export([f/0]).

      f() ->
          <<0 || _ <- [], _ <- ok, false>>.

  In Erlang/OTP 26 it would fail like so:

      > t:f().
      ** exception error: bad generator ok
           in function  t:f/0 (t.erl, line 6)

  In Erlang/OTP 27 it returns an empty binary:

      > t:f().
      <<>>

  Own Id: OTP-18703
  Related Id(s): GH-7494, PR-7538

- The documentation for the preprocessor now mentions that `defined(Name)` can
  be called in the condition for an `-if` or `-elif` directive to test whether
  `Name` is the name of a defined macro. (This feature was implemented in OTP
  21.)

  If a function call in an `-if` or `-elif` with a name that is not the name of
  a guard BIF, there would not be a compilation error, but would instead cause
  the lines following the directive to be skipped. This has now been changed to
  be a compilation error.

  Own Id: OTP-18784
  Related Id(s): GH-7706, PR-7726

  *** POTENTIAL INCOMPATIBILITY ***

## Improvements and New Features

- The compiler now emits nicer error message for function head mismatches. For
  example, given:

      a() -> ok;
      a(_) -> error.

  Erlang/OTP 26 and earlier would emit a diagnostic similar to:

      t.erl:6:1: head mismatch
      %    6| a(_) -> error.
      %     | ^

  while in Erlang/OTP 27 the diagnostic is similar to:

      t.erl:6:1: head mismatch: function a with arities 0 and 1 is regarded as two distinct functions. Is the number of arguments incorrect or is the semicolon in a/0 unwanted?
      %    6| a(_) -> error.
      %     | ^

  Own Id: OTP-18648
  Related Id(s): PR-7383

  *** HIGHLIGHT ***

- The compiler now optimizes creation of binaries that are known to be constant.

  Consider this example:

      bin() ->
          C = char(),
          <<C>>.

      char() -> $*.

  Essentially, the compiler rewrites the example to the slightly more efficient:

      bin() ->
          _ = char(),
          <<$*>>.

      char() -> $*.

  Own Id: OTP-18673
  Related Id(s): ERIERL-964, PR-7474

- The compiler will now merge consecutive updates of the same record.

  As an example, the body of the following function will be combined into a
  single tuple creation instruction:

      -record(r, {a,b,c,d}).

      update(Value) ->
          R0 = #r{},
          R1 = R0#r{a=Value},
          R2 = R1#r{b=2},
          R2#r{c=3}.

  Own Id: OTP-18680
  Related Id(s): ERIERL-967, PR-7491, PR-8086

  *** HIGHLIGHT ***

- Improved the performance of the alias analysis pass.

  Own Id: OTP-18714
  Related Id(s): GH-7432, PR-7528

- `-spec` attributes are now used for documentation.

  Own Id: OTP-18801
  Related Id(s): PR-7739

- Native coverage support has been implemented in the JIT. It will automatically
  be used by the `cover` tool to reduce the execution overhead when running
  cover-compiled code.

  There are also new APIs to support native coverage without using the `cover`
  tool.

  To instrument code for native coverage it must be compiled with the
  `line_coverage` option.

  To enable native coverage in the runtime system, start it like so:

      $ erl +JPcover true

  There are also the following new functions for supporting native coverage:

  - code:coverage_support/0
  - code:get_coverage/2
  - code:reset_coverage/1
  - code:get_coverage_mode/0
  - code:get_coverage_mode/1
  - code:set_coverage_mode/1

  Own Id: OTP-18856
  Related Id(s): PR-7856

  *** HIGHLIGHT ***

- EEP-59 - Documentation Attributes has been implemented.

  Documentation attributes can be used to document functions, types, callbacks,
  and modules. The keyword `-moduledoc "Documentation here".` is used to
  document modules, while `-doc "Documentation here".` can be used on top of
  functions, types, and callbacks to document them, respectively.

  - Types, callbacks, and function documentation can be set to `hidden` either
    via `-doc false` or `-doc hidden`. When documentation attributes mark a type
    as hidden, they will not be part of the documentation.
  - The documentation from `moduledoc` and `doc` gets added by default to the
    binary beam file, following the format of EEP-48.
  - Using the compiler flag `warn_missing_doc` will raise a warning when doc.
    attributes are missing in exported functions, types, and callbacks.
  - `moduledoc`s and `doc`s may refer to external files to be embedded, such as
    `-doc {file, "README.md"}.`, which refers to the file `README.md` found in
    the current working directory.
  - The compiler warns about exported functions whose specs refer to hidden
    types. Thus, there will be warnings when a hidden type (meaning, the type is
    not part of the documentation) gets used in an exported function.

  Own Id: OTP-18916
  Related Id(s): PR-7936

  *** HIGHLIGHT ***

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

- Safe destructive update of tuples has been implemented in the compiler and
  runtime system. This allows the VM to update tuples in-place when it is safe
  to do so, thus improving performance by doing less copying but also by
  producing less garbage.

  Example:

      -record(rec, {a,b,c}).

      update(#rec{a=needs_update,b=N}=R0) ->
          R = R0#rec{a=up_to_date},
          if
              N < 0 ->
                  R#rec{c=negative};
              N == 0 ->
                  R#rec{c=zero};
              N > 0 ->
                  R#rec{c=positive}
          end.

  The record updates in each of the three clauses of the `if` can safely be done
  in-place, because variable `R` is not used again.

  Own Id: OTP-18972
  Related Id(s): PR-8090

  *** HIGHLIGHT ***

> #### Full runtime dependencies of compiler-8.5
>
> crypto-5.1, erts-13.0, kernel-8.4, stdlib-6.0

# crypto-5.5

## Improvements and New Features

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

- Removed functions `crypto_dyn_iv_init/3` and `crypto_dyn_iv_update/3` which
  were marked as deprecated since OTP 25.

  Own Id: OTP-18973

- `OPENSSL_thread_stop` is called when `crypto` is purged to not leak thread
  specific data.

  Own Id: OTP-18978
  Related Id(s): 7809

> #### Full runtime dependencies of crypto-5.5
>
> erts-9.0, kernel-5.3, stdlib-3.9

# debugger-5.4

## Fixed Bugs and Malfunctions

- The dependencies for this application are now listed in the app file.

  Own Id: OTP-18831
  Related Id(s): PR-7441

## Improvements and New Features

- Type specs have been added to all API functions.

  Own Id: OTP-18819
  Related Id(s): PR-7781

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

> #### Full runtime dependencies of debugger-5.4
>
> compiler-8.0, erts-14.3, kernel-8.0, stdlib-3.15, wx-2.0

# dialyzer-5.2

## Improvements and New Features

- The `--gui` option for Dialyzer has been removed.

  Own Id: OTP-18667
  Related Id(s): PR-7443

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

> #### Full runtime dependencies of dialyzer-5.2
>
> compiler-8.0, erts-12.0, kernel-8.0, stdlib-5.0, syntax_tools-2.0

# diameter-2.4

## Improvements and New Features

- `-callback` attributes have been added to `diameter_app` and
  `diameter_transport`.

  Own Id: OTP-18783
  Related Id(s): PR-7699

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

> #### Full runtime dependencies of diameter-2.4
>
> erts-10.0, kernel-3.2, ssl-9.0, stdlib-5.0

# edoc-1.3

## Fixed Bugs and Malfunctions

- EEP 48 doc chunks now properly include links within `{@type }` macros.

  Own Id: OTP-18945
  Related Id(s): PR-8063

- `@hidden` now means `hidden` in EEP 48 doc chunks instead of `none`.

  Own Id: OTP-18946
  Related Id(s): PR-8063

## Improvements and New Features

- There is a new `edoc_html_to_markdown` module that can be used to convert
  EEP-48 `application/html+erlang` to Markdown.

  Own Id: OTP-18947
  Related Id(s): PR-8063

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

> #### Full runtime dependencies of edoc-1.3
>
> erts-11.0, inets-5.10, kernel-7.0, stdlib-4.0, syntax_tools-2.0, xmerl-1.3.7

# eldap-1.3

## Improvements and New Features

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

> #### Full runtime dependencies of eldap-1.3
>
> asn1-3.0, erts-6.0, kernel-3.0, ssl-5.3.4, stdlib-3.4

# erl_interface-5.6

## Improvements and New Features

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

## Known Bugs and Problems

- The `ei` API for decoding/encoding terms is not fully 64-bit compatible since
  terms that have a representation on the external term format larger than 2 GB
  cannot be handled.

  Own Id: OTP-16607
  Related Id(s): OTP-16608

# erts-14.3

## Fixed Bugs and Malfunctions

- Fix bugs in how `erl -extra` interacts with passing flags via ERL\_\*FLAGS or
  `-args_file`.

  Own Id: OTP-18766
  Related Id(s): PR-7639

- Fixed a bug that prevented the emulator from building on recent versions of
  Yocto Linux.

  Own Id: OTP-18918
  Related Id(s): PR-7952

- Fix spectre mitigation configure test to work with GCC patches to always add
  `-fcf-protection=full`.

  Own Id: OTP-18928
  Related Id(s): PR-8006

## Improvements and New Features

- Refactored how the JIT handles POSIX signals and how they affect thread
  stacks, allowing us to use the native stack register for Erlang stacks on more
  platforms.

  Notably, containers built on 64-bit x86 Alpine Linux images will now perform
  much better in sequential code. As an example, running `dialyzer` over the OTP
  code base finishes about 15% quicker.

  Own Id: OTP-18568
  Related Id(s): PR-7174

- The `instrument` module can now track allocations on a per-process or
  per-port basis.

  Own Id: OTP-18577
  Related Id(s): PR-7236

- The `pid` field has been removed from `erlang:fun_info/1,2`.

  Own Id: OTP-18594
  Related Id(s): PR-7274

  *** POTENTIAL INCOMPATIBILITY ***

- By default, escripts will now be compiled instead of interpreted. That means
  that the `compiler` application must be installed.

  Own Id: OTP-18639
  Related Id(s): PR-7348

  *** POTENTIAL INCOMPATIBILITY ***

- A binary returned from the `socket` receive functions is no longer created
  as a sub binary of an often large receive buffer binary (socket option
  `{otp,rcvbuf}`). This avoids space waste, trusting the allocators to implement
  reallocation efficiently.

  Own Id: OTP-18642
  Related Id(s): GH-6152, PR-7465

- The default process limit has been raised to `1048576` processes.

  Own Id: OTP-18699
  Related Id(s): PR-7388

- The erlang:system_monitor/2 functionality is now able to monitor long
  message queues in the system.

  Own Id: OTP-18709
  Related Id(s): PR-7651

- The `erl` command now supports the `-S` flag, which is similar to the `-run`
  flag, except that it will pass all arguments up to end of the command line to
  the called function. (The `-run` flag will not pass arguments beginning with a
  hyphen.) Another difference is that `-S` will always call a function with one
  argument, passing an empty list if no arguments were given.

  Own Id: OTP-18744
  Related Id(s): PR-7470

  *** HIGHLIGHT ***

- When implementing an alternative carrier for the Erlang distribution, a
  separate input handler process may now be registered, using
  erlang:dist_ctrl_input_handler/2, also in the case when the distribution
  controller is a port.

  Own Id: OTP-18774
  Related Id(s): PR-7110

- Add call stack trace to the error reported by erlang:process_flag/2 when
  `max_heap_size` has been exceeded.

  Own Id: OTP-18779
  Related Id(s): PR-7592

- `-callback` attributes have been added to `erl_tracer`.

  Own Id: OTP-18794
  Related Id(s): PR-7703

- For `inet_backend = socket`, setting the `active` socket option alone, to
  `once`, `true` or `N`, has been optimized, as well as the corresponding data
  delivery.

  Own Id: OTP-18835

- Socket options that take string now also accept binaries.

  Own Id: OTP-18849
  Related Id(s): PR-6510

- Native coverage support has been implemented in the JIT. It will automatically
  be used by the `cover` tool to reduce the execution overhead when running
  cover-compiled code.

  There are also new APIs to support native coverage without using the `cover`
  tool.

  To instrument code for native coverage it must be compiled with the
  `line_coverage` option.

  To enable native coverage in the runtime system, start it like so:

      $ erl +JPcover true

  There are also the following new functions for supporting native coverage:

  - code:coverage_support/0
  - code:get_coverage/2
  - code:reset_coverage/1
  - code:get_coverage_mode/0
  - code:get_coverage_mode/1
  - code:set_coverage_mode/1

  Own Id: OTP-18856
  Related Id(s): PR-7856

  *** HIGHLIGHT ***

- Changed the default value of the command line flag `-code_path_choice Choice`
  to `strict`.

  Own Id: OTP-18894
  Related Id(s): PR-7243

- Added module loading to `erl -init_debug` printouts.

  Own Id: OTP-18929
  Related Id(s): PR-8004

- Optimized code loading by moving certain operations from the code server to
  the caller.

  Own Id: OTP-18941
  Related Id(s): PR-7981

- Updated asmjit to version a465fe71ab3d0e224b2b4bd0fac69ae68ab9239d

  Own Id: OTP-18942

- The deprecated functions in `zlib` have been removed. That includes
  `inflateChunk/{1,2}`, `getBufSize/1`, `setBufSize/2`, the CRC32 functions, and
  the Adler checksum functions.

  Own Id: OTP-18950

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

- Safe destructive update of tuples has been implemented in the compiler and
  runtime system. This allows the VM to update tuples in-place when it is safe
  to do so, thus improving performance by doing less copying but also by
  producing less garbage.

  Example:

      -record(rec, {a,b,c}).

      update(#rec{a=needs_update,b=N}=R0) ->
          R = R0#rec{a=up_to_date},
          if
              N < 0 ->
                  R#rec{c=negative};
              N == 0 ->
                  R#rec{c=zero};
              N > 0 ->
                  R#rec{c=positive}
          end.

  The record updates in each of the three clauses of the `if` can safely be done
  in-place, because variable `R` is not used again.

  Own Id: OTP-18972
  Related Id(s): PR-8090

  *** HIGHLIGHT ***

- The obsolete and undocumented support for opening a port to an external
  resource by passing an atom (or a string) as first argument to `open_port()`,
  implemented by the vanilla driver, has been removed. This feature has been
  scheduled for removal in OTP 27 since the release of OTP 26.

  Own Id: OTP-18976
  Related Id(s): PR-7125

- Add optional NIF callback `ERL_NIF_OPT_ON_UNLOAD_THREAD` to be called by all
  scheduler thread when a NIF library is unloaded. Used for releasing thread
  specific data. Can be set with function `enif_set_option`.

  Own Id: OTP-18977
  Related Id(s): PR-7809

- Multiple trace sessions.

  Own Id: OTP-18980
  *** HIGHLIGHT ***

> #### Full runtime dependencies of erts-14.3
>
> kernel-9.0, sasl-3.3, stdlib-4.1

# et-1.8

## Fixed Bugs and Malfunctions

- The dependencies for this application are now listed in the app file.

  Own Id: OTP-18831
  Related Id(s): PR-7441

- Dialyzer warnings due to type specs added in `dbg` have been eliminated.

  Own Id: OTP-18860

## Improvements and New Features

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

> #### Full runtime dependencies of et-1.8
>
> erts-9.0, kernel-5.3, runtime_tools-1.10, stdlib-3.4, wx-1.2

# eunit-2.10

## Improvements and New Features

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

> #### Full runtime dependencies of eunit-2.10
>
> erts-9.0, kernel-5.3, stdlib-3.4

# ftp-1.3

## Fixed Bugs and Malfunctions

- Dialyzer warnings due to type specs added in `dbg` have been eliminated.

  Own Id: OTP-18860

## Improvements and New Features

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

> #### Full runtime dependencies of ftp-1.3
>
> erts-7.0, kernel-6.0, runtime_tools-1.15.1, ssl-10.2, stdlib-3.5

# inets-9.2

## Improvements and New Features

- Introduce default value for httpd_server name configuration to improve ease of
  use.

  Own Id: OTP-18641
  Related Id(s): PR-7316

  *** POTENTIAL INCOMPATIBILITY ***

- With this change, `erl -S httpd` command can be used for serving current
  directory content over HTTP.

  Own Id: OTP-18727
  Related Id(s): PR-7299

- Add `-callback` attributes to `httpd`, `mod_esi` and `mod_security`.

  Own Id: OTP-18786
  Related Id(s): PR-7700

- Use a relative redirect with an absolute path to prevent whoever is running
  inets from having to configure the ServerName to match the network-reachable
  hostname of the server.

  Own Id: OTP-18809

- Use proc_lib:set_label/1 to increase observability of inets processes.

  Own Id: OTP-18927

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

> #### Full runtime dependencies of inets-9.2
>
> erts-14.0, kernel-9.0, mnesia-4.12, public_key-1.13, runtime_tools-1.8.14,
> ssl-9.0, stdlib-5.0, stdlib-6.0

# jinterface-1.15

## Improvements and New Features

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

# kernel-9.3

## Fixed Bugs and Malfunctions

- Fixed a crash when calling file:delete/2 with an empty option list.

  Own Id: OTP-18590
  Related Id(s): PR-7220

- New functions have been added to the undocumented module `inet_dns` that
  take a flag to specify if encode/decode is for mDNS. This affects how CLASS
  values in the private range, with the top bit set, are handled.

  Own Id: OTP-18878
  Related Id(s): GH-7718, OTP-17734

- The error information for erlang:phash/2 has been corrected.

  Own Id: OTP-18904
  Related Id(s): PR-7960

- `get_until` requests using the I/O protocol now correctly return a binary or
  list when `eof` is the last item returned by the callback.

  Own Id: OTP-18930
  Related Id(s): GH-4992, PR-7993

- Calling logger:add_handlers/1 with config option now works.

  Own Id: OTP-18954
  Related Id(s): GH-8061, PR-8076

- The code:del_path/1 function now also works on paths added through `-pa`,
  `-pz` , `-path` and the boot script.

  Own Id: OTP-18959
  Related Id(s): GH-6692, PR-7697

## Improvements and New Features

- Added file:read_file/2 with a `raw` option for reading files without going
  through the file server.

  Own Id: OTP-18589
  Related Id(s): PR-7220

- The undocumented Erlang DNS resolver library (`inet_dns` and `inet_res`) has
  been augmented to handle IXFR, NOTIFY, UPDATE and TSIG records. With this some
  bug fixes and code cleanup has been done, and the resolver used in the test
  suite has been changed to Knot DNS. See the source code.

  Kudos to Alexander Clouter that did almost all the work!

  Own Id: OTP-18713
  Related Id(s): GH-6985, PR-6985

- The `ebin` directories for escripts are now cached.

  Own Id: OTP-18778
  Related Id(s): PR-7556

- Add `-callback` attributes to `application`, `logger_handler` and
  `logger_formatter`.

  Own Id: OTP-18795
  Related Id(s): PR-7703

- Progress reports from before logger is started are now logged when log level
  is set to debug.

  Own Id: OTP-18807
  Related Id(s): ERIERL-985, PR-7732

- The code:where_is_file/2 and code:which/1 functions now check for
  existence of the file directly instead of listing the content of each
  directory in the code path.

  Own Id: OTP-18816
  Related Id(s): PR-7711

- Type specs has been added to the `logger:Level/1,2,3` functions.

  Own Id: OTP-18820
  Related Id(s): PR-7779

- For `inet_backend = socket`, setting the `active` socket option alone, to
  `once`, `true` or `N`, has been optimized, as well as the corresponding data
  delivery.

  Own Id: OTP-18835

- The shell now pages long output from the help command (`h(Module)`), auto
  completions and the search command.

  Own Id: OTP-18846
  Related Id(s): PR-7845

- Native coverage support has been implemented in the JIT. It will automatically
  be used by the `cover` tool to reduce the execution overhead when running
  cover-compiled code.

  There are also new APIs to support native coverage without using the `cover`
  tool.

  To instrument code for native coverage it must be compiled with the
  `line_coverage` option.

  To enable native coverage in the runtime system, start it like so:

      $ erl +JPcover true

  There are also the following new functions for supporting native coverage:

  - code:coverage_support/0
  - code:get_coverage/2
  - code:reset_coverage/1
  - code:get_coverage_mode/0
  - code:get_coverage_mode/1
  - code:set_coverage_mode/1

  Own Id: OTP-18856
  Related Id(s): PR-7856

  *** HIGHLIGHT ***

- Optimized code loading by moving certain operations from the code server to
  the caller.

  Own Id: OTP-18941
  Related Id(s): PR-7981

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

- Application startup has been optimized by removing an intermediary process.

  Own Id: OTP-18963
  Related Id(s): PR-8042

- The undocumented and deprecated `file:pid2name` function has been removed.

  Own Id: OTP-18967
  Related Id(s): PR-8092

> #### Full runtime dependencies of kernel-9.3
>
> crypto-5.0, erts-14.3, sasl-3.0, stdlib-6.0

# megaco-4.6

## Improvements and New Features

- `-callback` attributes have been added to `megaco_transport`.

  Own Id: OTP-18806
  Related Id(s): PR-7740

- Updated types and specs for all API modules.

  Own Id: OTP-18920
  Related Id(s): BL-322

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

> #### Full runtime dependencies of megaco-4.6
>
> asn1-3.0, debugger-4.0, erts-12.0, et-1.5, kernel-8.0, runtime_tools-1.8.14,
> stdlib-2.5

# mnesia-4.24

## Improvements and New Features

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

> #### Full runtime dependencies of mnesia-4.24
>
> erts-9.0, kernel-5.3, stdlib-5.0

# observer-2.16

## Fixed Bugs and Malfunctions

- The dependencies for this application are now listed in the app file.

  Own Id: OTP-18831
  Related Id(s): PR-7441

## Improvements and New Features

- The new function proc_lib:set_label/1 can be used to add a descriptive term
  to any process that does not have a registered name. The name will be shown by
  tools such as `\c:i/0`, `observer`, and it will be included in crash reports
  produced by processes using `gen_server`, `gen_statem`, `gen_event`, and
  `gen_fsm`.

  The label for a process can be retrieved by calling proc_lib:get_label/1.

  Note that those functions work on any process, not only processes that use
  `proc_lib`.

  Example:

      1> self().
      <0.90.0>
      2> proc_lib:set_label(my_label).
      ok
      3> i().
          .
          .
          .
      <0.90.0>              erlang:apply/2                        2586    75011    0
      my_label              c:pinfo/2                               51
      4> proc_lib:get_label(self()).
      my_label

  Own Id: OTP-18789
  Related Id(s): PR-7720, PR-8003

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

> #### Full runtime dependencies of observer-2.16
>
> erts-14.0, et-1.5, kernel-9.0, runtime_tools-1.19, stdlib-5.0, wx-2.3

# odbc-2.15

## Improvements and New Features

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

> #### Full runtime dependencies of odbc-2.15
>
> erts-6.0, kernel-3.0, stdlib-2.0

# os_mon-2.10

## Improvements and New Features

- Function specifications and types have been added to all public API functions.

  Own Id: OTP-18913

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

> #### Full runtime dependencies of os_mon-2.10
>
> erts-14.0, kernel-9.0, sasl-4.2.1, stdlib-5.0

# parsetools-2.6

## Improvements and New Features

- The `leex` documentation has been updated to use specs for documenting the
  generated interface.

  Own Id: OTP-18796
  Related Id(s): PR-7703

- yecc now wraps the `-module` attribute with `-file` to indicate the `.yrl`
  source file.

  Own Id: OTP-18912
  Related Id(s): PR-7963

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

> #### Full runtime dependencies of parsetools-2.6
>
> erts-6.0, kernel-3.0, stdlib-3.4

# public_key-1.16

## Improvements and New Features

- The `ssl` client can negotiate and handle certificate status request (OCSP
  stapling support on the client side).

  Own Id: OTP-18606
  Related Id(s): OTP-16448, OTP-16875

- Improved exception reason when public_key:cacerts_get/0 failed.

  Own Id: OTP-18609
  Related Id(s): GH-7295, PR-7202

- Key customization support has been extended to allow flexibility for
  implementers of for instance hardware security modules (HSM) or trusted
  platform modules (TPM).

  Own Id: OTP-18876
  Related Id(s): PR-7475, PR-7898

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

> #### Full runtime dependencies of public_key-1.16
>
> asn1-3.0, crypto-4.6, erts-6.0, kernel-3.0, stdlib-3.5

# reltool-1.1

## Fixed Bugs and Malfunctions

- The dependencies for this application are now listed in the app file.

  Own Id: OTP-18831
  Related Id(s): PR-7441

## Improvements and New Features

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

> #### Full runtime dependencies of reltool-1.1
>
> erts-14.3, kernel-9.0, sasl-4.2.1, stdlib-5.0, tools-2.6.14, wx-2.3

# runtime_tools-2.1

## Improvements and New Features

- The `instrument` module can now track allocations on a per-process or
  per-port basis.

  Own Id: OTP-18577
  Related Id(s): PR-7236

- The new function proc_lib:set_label/1 can be used to add a descriptive term
  to any process that does not have a registered name. The name will be shown by
  tools such as `\c:i/0`, `observer`, and it will be included in crash reports
  produced by processes using `gen_server`, `gen_statem`, `gen_event`, and
  `gen_fsm`.

  The label for a process can be retrieved by calling proc_lib:get_label/1.

  Note that those functions work on any process, not only processes that use
  `proc_lib`.

  Example:

      1> self().
      <0.90.0>
      2> proc_lib:set_label(my_label).
      ok
      3> i().
          .
          .
          .
      <0.90.0>              erlang:apply/2                        2586    75011    0
      my_label              c:pinfo/2                               51
      4> proc_lib:get_label(self()).
      my_label

  Own Id: OTP-18789
  Related Id(s): PR-7720, PR-8003

- Type specs had been added to all `dbg` functions.

  Own Id: OTP-18859
  Related Id(s): PR-7782

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

> #### Full runtime dependencies of runtime_tools-2.1
>
> erts-14.2, kernel-8.1, mnesia-4.12, stdlib-6.0

# sasl-4.3

## Improvements and New Features

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

> #### Full runtime dependencies of sasl-4.3
>
> erts-14.3, kernel-6.0, stdlib-4.0, tools-2.6.14

# snmp-5.16

## Improvements and New Features

- `-callback` attributes have been added to modules
  `snmpa_network_interface_filter`, `snmpa_notification_filter`,
  `snmpm_network_interface_filter`, `snmpm_user`, and
  `snmpa_notification_delivery_info_receiver`.

  New `-type` attributes have also been added to modules `snmp`, `snmpa`,
  `snmpm`, and `snmpa_conf` to support the previously mentioned callbacks.

  Own Id: OTP-18785
  Related Id(s): PR-7702

- Updated types and specs for all API modules.

  Own Id: OTP-18934
  Related Id(s): #312

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

> #### Full runtime dependencies of snmp-5.16
>
> crypto-4.6, erts-12.0, kernel-8.0, mnesia-4.12, runtime_tools-1.8.14,
> stdlib-5.0

# ssh-5.2

## Improvements and New Features

- The shell now pages long output from the help command (`h(Module)`), auto
  completions and the search command.

  Own Id: OTP-18846
  Related Id(s): PR-7845

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

- Updated types and specs for all API modules.

  Own Id: OTP-18961

> #### Full runtime dependencies of ssh-5.2
>
> crypto-5.0, erts-14.0, kernel-9.0, public_key-1.6.1, runtime_tools-1.15.1,
> stdlib-5.0, stdlib-5.0

# ssl-11.2

## Fixed Bugs and Malfunctions

- Starting a TLS server without sufficient credentials (certificate or anonymous
  cipher) would work, but it was impossible to connect to it.

  This has been corrected to return an error instead of starting the server.

  Own Id: OTP-18887
  Related Id(s): GH-7493, PR-7918

## Improvements and New Features

- The `ssl` client can negotiate and handle certificate status request (OCSP
  stapling support on the client side).

  Own Id: OTP-18606
  Related Id(s): OTP-16448, OTP-16875

- Added ssl_crl_cache_api:lookup/2 as an optional `-callback` attribute.

  Own Id: OTP-18788
  Related Id(s): PR-7700

- Key customization support has been extended to allow flexibility for
  implementers of for instance hardware security modules (HSM) or trusted
  platform modules (TPM).

  Own Id: OTP-18876
  Related Id(s): PR-7475, PR-7898

- The proc_lib:set_label/1 function is now used to increase observability of
  `ssl` processes.

  Own Id: OTP-18879

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

> #### Full runtime dependencies of ssl-11.2
>
> crypto-5.0, erts-14.3, inets-5.10.7, kernel-9.0, public_key-1.16,
> runtime_tools-1.15.1, stdlib-6.0

# stdlib-6.0

## Fixed Bugs and Malfunctions

- The specs in module `binary` has been updated to reflect what is allowed by
  the documentation.

  Own Id: OTP-18684
  Related Id(s): PR-7481

- Several functions in the `binary` module would accept arguments of the wrong
  type under certain circumstances. In this release, they now raise an exception
  when incorrect types are given.

  The following functions would accept an invalid pattern if the subject binary
  was empty or if the `{scope,{0,0}}` option was given: `binary:match/2,3`,
  `binary:matches/2,3`, `binary:replace/3,4`, and `binary:split/2,3`

  The call `binary:copy(<<1:1>>, 0)` would return an empty binary instead of
  raising an exception. Similarly, calls to `binary:part/2,3` attempting to
  extract 0 bytes at position 0 of a bitstring would return an empty binary
  instead of raising an exception.

  Own Id: OTP-18743
  Related Id(s): PR-7607, PR-7628

- The documentation for the preprocessor now mentions that `defined(Name)` can
  be called in the condition for an `-if` or `-elif` directive to test whether
  `Name` is the name of a defined macro. (This feature was implemented in OTP
  21.)

  If a function call in an `-if` or `-elif` with a name that is not the name of
  a guard BIF, there would not be a compilation error, but would instead cause
  the lines following the directive to be skipped. This has now been changed to
  be a compilation error.

  Own Id: OTP-18784
  Related Id(s): GH-7706, PR-7726

  *** POTENTIAL INCOMPATIBILITY ***

- `get_until` requests using the I/O protocol now correctly return a binary or
  list when `eof` is the last item returned by the callback.

  Own Id: OTP-18930
  Related Id(s): GH-4992, PR-7993

## Improvements and New Features

- The functions `is_equal/2`, `map/2`, and `filtermap/2` have been added to the
  modules `sets`, `ordsets`, and `gb_sets`.

  Own Id: OTP-18622
  Related Id(s): GH-7183, GH-7232

  *** HIGHLIGHT ***

- The compiler now emits nicer error message for function head mismatches. For
  example, given:

      a() -> ok;
      a(_) -> error.

  Erlang/OTP 26 and earlier would emit a diagnostic similar to:

      t.erl:6:1: head mismatch
      %    6| a(_) -> error.
      %     | ^

  while in Erlang/OTP 27 the diagnostic is similar to:

      t.erl:6:1: head mismatch: function a with arities 0 and 1 is regarded as two distinct functions. Is the number of arguments incorrect or is the semicolon in a/0 unwanted?
      %    6| a(_) -> error.
      %     | ^

  Own Id: OTP-18648
  Related Id(s): PR-7383

  *** HIGHLIGHT ***

- `zip:create/2,3` will now tolerate POSIX timestamps in the provided
  `file_info` records.

  Own Id: OTP-18668

- The callback function gen_statem:handle_event/4 has been cached in the
  `gen_statem` engine to optimize callback call speed.

  Own Id: OTP-18671
  Related Id(s): PR-7419

- The type beam_lib:beam/0 is now exported.

  Own Id: OTP-18716
  Related Id(s): PR-7534

- The documentation for the `binary` module has been improved.

  Own Id: OTP-18741
  Related Id(s): PR-7585

- `binary:replace/3,4` now supports using a fun for supplying the replacement
  binary.

  Own Id: OTP-18742
  Related Id(s): PR-7590

- Triple-Quoted Strings has been implemented as per EEP 64. See String in the
  Reference Manual.

  Example:

      1> """
         a
         b
         c
         """.
      "a\nb\nc"

  Adjacent string literals without intervening white space is now a syntax
  error, to avoid possible confusion with triple-quoted strings. For example:

      1> "abc""xyz".
      "xyz".
      * 1:6: adjacent string literals without intervening white space

  Own Id: OTP-18750
  Related Id(s): PR-7313, PR-7451, OTP-18746

  *** HIGHLIGHT ***

  *** POTENTIAL INCOMPATIBILITY ***

- The new function proc_lib:set_label/1 can be used to add a descriptive term
  to any process that does not have a registered name. The name will be shown by
  tools such as `\c:i/0`, `observer`, and it will be included in crash reports
  produced by processes using `gen_server`, `gen_statem`, `gen_event`, and
  `gen_fsm`.

  The label for a process can be retrieved by calling proc_lib:get_label/1.

  Note that those functions work on any process, not only processes that use
  `proc_lib`.

  Example:

      1> self().
      <0.90.0>
      2> proc_lib:set_label(my_label).
      ok
      3> i().
          .
          .
          .
      <0.90.0>              erlang:apply/2                        2586    75011    0
      my_label              c:pinfo/2                               51
      4> proc_lib:get_label(self()).
      my_label

  Own Id: OTP-18789
  Related Id(s): PR-7720, PR-8003

- `-callback` attributes has been added to modules `sys` and `erl_error`.

  Own Id: OTP-18793
  Related Id(s): PR-7703

- Several new functions that accept funs have been added to module `timer`.

  Functions `apply_after/2`, `apply_interval/2`, and `apply_repeatedly/2` accept
  a 0-ary fun as the second argument, while functions `apply_after/3`,
  `apply_interval/3`, and `apply_repeatedly/3` accept an n-ary fun as the second
  and a list of n arguments for the fun as the third argument.

  Own Id: OTP-18808
  Related Id(s): PR-7649

  *** HIGHLIGHT ***

- Sigils on string literals have been implemented as per EEP 66, that is:
  binary and string sigils in verbatim and escape characters variants, as well
  as a default (vanilla) Sigil. All for ordinary strings and for triple-quoted
  strings (EEP 64). See Sigils in the Reference Manual.

  Examples:

      1> ~"Björn".
      <<"Björn"/utf8>>
      2> ~b"Björn".
      <<"Björn"/utf8>>
      3> ~S"\s*(\w+)".
      "\\s*(\\w+)"
      4> ~B"\s*(\w+)".
      <<"\\s*(\\w+)">>

  Own Id: OTP-18825
  Related Id(s): PR-7684, OTP-18750

  *** HIGHLIGHT ***

- Functions shell:default_multiline_prompt/1, shell:inverted_space_prompt/1,
  and shell:prompt_width/1 have been exported to help with custom prompt
  implementations.

  Own Id: OTP-18834
  Related Id(s): PR-7675, PR-7816

- The shell now pages long output from the help command (`h(Module)`), auto
  completions and the search command.

  Own Id: OTP-18846
  Related Id(s): PR-7845

- The `M-h` hotkey (Alt/Option-h) now outputs help for the module or function
  directly before the cursor.

  Own Id: OTP-18847
  Related Id(s): PR-7846

- Added support for adding a custom code formatter that formats your multi-line
  shell commands in your preferred formatting on submission. See
  `shell:format_shell_func/` and shell:erl_pp_format_func/1.

  Own Id: OTP-18848
  Related Id(s): PR-7847

- Added shell functions for viewing, forgetting and saving locally defined
  functions, types and records.

  Own Id: OTP-18852
  Related Id(s): PR-7844

- Added string:jaro_similarity/2, which can be used to calculate the
  similarity between two strings.

  Own Id: OTP-18865
  Related Id(s): PR-7879

- The new function ets:update_element/4 is similar to ets:update_element/3,
  but takes a default tuple as the fourth argument, which will be inserted if no
  previous record with that key exists.

  Own Id: OTP-18870
  Related Id(s): PR-7857

- Added functions to retrieve the next higher or lower key/element from
  `gb_trees` and `gb_sets`, as well as returning iterators that start at
  given keys/elements.

  Own Id: OTP-18874
  Related Id(s): PR-7745

- When he shell built-in function `c/1,2` is used to re-compile a module,
  the current working directory of the original compilation is now added to the
  include path.

  
  Own Id: OTP-18908
  Related Id(s): PR-7957

- The `timer` module now uses a private table for its internal state, slightly
  improving its performance.

  Own Id: OTP-18914
  Related Id(s): PR-7973

- EEP-59 - Documentation Attributes has been implemented.

  Documentation attributes can be used to document functions, types, callbacks,
  and modules. The keyword `-moduledoc "Documentation here".` is used to
  document modules, while `-doc "Documentation here".` can be used on top of
  functions, types, and callbacks to document them, respectively.

  - Types, callbacks, and function documentation can be set to `hidden` either
    via `-doc false` or `-doc hidden`. When documentation attributes mark a type
    as hidden, they will not be part of the documentation.
  - The documentation from `moduledoc` and `doc` gets added by default to the
    binary beam file, following the format of EEP-48.
  - Using the compiler flag `warn_missing_doc` will raise a warning when doc.
    attributes are missing in exported functions, types, and callbacks.
  - `moduledoc`s and `doc`s may refer to external files to be embedded, such as
    `-doc {file, "README.md"}.`, which refers to the file `README.md` found in
    the current working directory.
  - The compiler warns about exported functions whose specs refer to hidden
    types. Thus, there will be warnings when a hidden type (meaning, the type is
    not part of the documentation) gets used in an exported function.

  Own Id: OTP-18916
  Related Id(s): PR-7936

  *** HIGHLIGHT ***

- New `ets` functions ets:first_lookup/1, ets:next_lookup/2,
  ets:prev_lookup/2 and ets:last_lookup/1. Example: ets:next_lookup/1 is
  equivalent to ets:next/2 followed by ets:lookup/2 with the next key. The
  new combined functions are more efficient and with guaranteed atomicity.

  Own Id: OTP-18923
  Related Id(s): PR-6791

  *** HIGHLIGHT ***

- The `maybe` expression is now enabled by default.

  To use `maybe` as an atom, it needs to be single-quoted. Alternatively, the
  `maybe` expression can be disabled by disabling the `maybe_expr` feature. That
  can be done by placing the following the line at the beginning of an Erlang
  source file:

      -feature(maybe_expr, disable).

  Another way to disable the `maybe_expr` feature is by passing the
  `-disable-feature` option to `erlc`:

      erlc -disable-feature maybe_expr some_file.erl

  Own Id: OTP-18944
  Related Id(s): PR-8067

  *** HIGHLIGHT ***

- The compiler will now raise a warning when updating record/map literals. As an
  example, consider this module:

      -module(t).
      -export([f/0]).
      -record(r, {a,b,c}).

      f() ->
          #r{a=1}#r{b=2}.

  The compiler raises the following warning:

      1> c(t).
      t.erl:6:12: Warning: expression updates a literal
      %    6|     #r{a=1}#r{b=2}.
      %     |            ^

  Own Id: OTP-18951
  Related Id(s): PR-8069

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

> #### Full runtime dependencies of stdlib-6.0
>
> compiler-5.0, crypto-4.5, erts-14.3, kernel-9.3, sasl-3.0

# syntax_tools-3.2

## Fixed Bugs and Malfunctions

- The `epp_dodger` module can now handle the `maybe` and `else` keywords.

  Own Id: OTP-18608
  Related Id(s): GH-7266, PR-7267

- Reverting a `#wrapper` will no longer throw away changes made to
  positions/annotations.

  Own Id: OTP-18805
  Related Id(s): PR-7398

## Improvements and New Features

- The type erl_syntax:annotation_or_location/0 is now exported.

  Own Id: OTP-18715
  Related Id(s): PR-7535

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

> #### Full runtime dependencies of syntax_tools-3.2
>
> compiler-7.0, erts-9.0, kernel-5.0, stdlib-4.0

# tftp-1.2

## Improvements and New Features

- There is now a new `tftp_logger` callback behavior module.

  Own Id: OTP-18787
  Related Id(s): PR-7700

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

> #### Full runtime dependencies of tftp-1.2
>
> erts-6.0, kernel-6.0, stdlib-5.0

# tools-4.0

## Fixed Bugs and Malfunctions

- Dialyzer warnings due to type specs added in `dbg` have been eliminated.

  Own Id: OTP-18860

## Improvements and New Features

- Triple-Quoted Strings has been implemented as per EEP 64. See String in the
  Reference Manual.

  Example:

      1> """
         a
         b
         c
         """.
      "a\nb\nc"

  Adjacent string literals without intervening white space is now a syntax
  error, to avoid possible confusion with triple-quoted strings. For example:

      1> "abc""xyz".
      "xyz".
      * 1:6: adjacent string literals without intervening white space

  Own Id: OTP-18750
  Related Id(s): PR-7313, PR-7451, OTP-18746

  *** HIGHLIGHT ***

  *** POTENTIAL INCOMPATIBILITY ***

- There is a new tool `tprof`, which combines the functionality of `eprof`
  and `cprof` under one interface. It also adds heap profiling.

  Own Id: OTP-18756
  Related Id(s): PR-6639

- Native coverage support has been implemented in the JIT. It will automatically
  be used by the `cover` tool to reduce the execution overhead when running
  cover-compiled code.

  There are also new APIs to support native coverage without using the `cover`
  tool.

  To instrument code for native coverage it must be compiled with the
  `line_coverage` option.

  To enable native coverage in the runtime system, start it like so:

      $ erl +JPcover true

  There are also the following new functions for supporting native coverage:

  - code:coverage_support/0
  - code:get_coverage/2
  - code:reset_coverage/1
  - code:get_coverage_mode/0
  - code:get_coverage_mode/1
  - code:set_coverage_mode/1

  Own Id: OTP-18856
  Related Id(s): PR-7856

  *** HIGHLIGHT ***

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

> #### Full runtime dependencies of tools-4.0
>
> compiler-8.5, erts-14.3, erts-14.3, kernel-9.3, runtime_tools-2.1, stdlib-6.0

# wx-2.5

## Improvements and New Features

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

> #### Full runtime dependencies of wx-2.5
>
> erts-12.0, kernel-8.0, stdlib-5.0

# xmerl-1.4

## Improvements and New Features

- Function specifications and types have been added to all public API functions.

  Own Id: OTP-18913

- As an alternative to `xmerl_xml`, a new export module `xmerl_xml_indent` that
  provides out-of-the box indented output has been added.

  Own Id: OTP-18922
  Related Id(s): PR-7942

- The documentation has been migrated to use Markdown and ExDoc.

  Own Id: OTP-18955
  Related Id(s): PR-8026

  *** HIGHLIGHT ***

> #### Full runtime dependencies of xmerl-1.4
>
> erts-6.0, kernel-3.0, stdlib-2.5