[Caml-list] OCaml 4.09.0+beta2

[Caml-list] OCaml 4.09.0+beta2

[Florian Angeletti]

Dear OCaml users,

The release of OCaml 4.09.0 is approaching. We have created a second 
beta version
to help you adapt your softwares to the new features ahead of the release.

This new beta integrates in particular the fixes from 4.08.1 that were 
not yet
part of the first beta due to the overlap between the release of 4.08.1 
and the
first beta.

If you tried to test the first beta, and were stopped by the lack of 
working dune
and ocamlfind, those issues has been fixed.

The source code is available at these addresses:

  https://github.com/ocaml/ocaml/archive/4.09.0+beta2.tar.gz
  https://caml.inria.fr/pub/distrib/ocaml-4.09/ocaml-4.09.0+beta2.tar.gz

The compiler can also be installed as an OPAM switch with one of the
following commands.

opam switch create ocaml-variants.4.09.0+beta2 
--repositories=default,beta=git+https://github.com/ocaml/ocaml-beta-repository.git

or

opam switch create ocaml-variants.4.09.0+beta2+<VARIANT> 
--repositories=default,beta=git+https://github.com/ocaml/ocaml-beta-repository.git

  where you replace <VARIANT> with one of these:
    afl
    default-unsafe-string
    flambda
    fp
    fp+flambda

We want to know about all bugs. Please report them here:
  https://github.com/ocaml/ocaml/issues

Happy hacking
— Florian "octachron" Angeletti, for the OCaml team


OCaml 4.09.0
------------------

(Changes that can break existing programs are marked with a "*")

### Code generation and optimizations:

- #2278: Remove native code generation support for 32-bit Intel macOS,
   iOS and other Darwin targets.
   (Mark Shinwell, review by Nicolas Ojeda Bar and Xavier Leroy)

- #8507: Shorten symbol names of anonymous functions in Flambda mode
   (the directory portions are now hidden)
   (Mark Shinwell, review by Nicolás Ojeda Bär)

- #7931, #1904: Add FreeBSD/aarch64 support
   (Greg V, review by Sébastien Hinderer, Stephen Dolan, Damien Doligez
    and Xavier Leroy)

- #8547: Optimize matches that are an affine function of the input.
   (Stefan Muenzel, review by Alain Frisch, Gabriel Scherer)

- #8681, #8699, #8712: Fix code generation with nested let rec of functions.
   (Stephen Dolan, Leo White, Gabriel Scherer and Pierre Chambart,
    review by Gabriel Scherer, reports by Alexey Solovyev and Jonathan 
French)

### Compiler user-interface and warnings:

* #2276: Remove support for compiler plugins and hooks (also adds
   [Dynlink.unsafe_get_global_value])
   (Mark Shinwell, Xavier Clerc, review by Nicolás Ojeda Bär,
   Florian Angeletti, David Allsopp and Xavier Leroy)

- #2301: Hint on type error on int literal
   (Jules Aguillon, review by Nicolás Ojeda Bär , Florian Angeletti,
   Gabriel Scherer and Armaël Guéneau)

- #2309: New options -with-runtime and -without-runtime in ocamlopt/ocamlc
   that control the inclusion of the runtime system in the generated 
program.
   (Lucas Pluvinage, review by Daniel Bünzli, Damien Doligez, David Allsopp
    and Florian Angeletti)

- #2314: Remove support for gprof profiling.
   (Mark Shinwell, review by Xavier Clerc and Stephen Dolan)

- #3819, #8546 more explanations and tests for illegal permutation
   (Florian Angeletti, review by Gabriel Scherer)

- #8537: fix the -runtime-variant option for bytecode
   (Damien Doligez, review by David Allsopp)

- #8541: Correctly print multi-lines locations
   (Louis Roché, review by Gabriel Scherer)

- #8579: Better error message for private constructors
   of an extensible variant type
   (Guillaume Bury, review by many fine eyes)

### Compiler distribution build system:

- #2267: merge generation of header programs, also fixing parallel build on
   Cygwin.
   (David Allsopp, review by Sébastien Hinderer)

- #8514: Use boot/ocamlc.opt for building, if available.
   (Stephen Dolan, review by Gabriel Scherer)

### Internal/compiler-libs changes:

- #1579: Add a separate types for clambda primitives
   (Pierre Chambart, review by Vincent Laviron and Mark Shinwell)

- #1965: remove loop constructors in Cmm and Mach
   (Vincent Laviron)

- #1973: fix compilation of catches with multiple handlers
   (Vincent Laviron)

- #2190: fix pretty printing (using Pprintast) of "lazy ..." patterns and
   "fun (type t) -> ..." expressions.
   (Nicolás Ojeda Bär, review by Gabriel Scherer)

- #2228, #8545: refactoring the handling of .cmi files
   by moving the logic from Env to a new module Persistent_env
   (Gabriel Scherer, review by Jérémie Dimino and Thomas Refis)

- #2229: Env: remove prefix_idents cache
   (Thomas Refis, review by Frédéric Bour and Gabriel Scherer)

- #2237, #8582: Reorder linearisation of Trywith to avoid a call instruction
   (Vincent Laviron and Greta Yorsh, additional review by Mark Shinwell;
   fix in #8582 by Mark Shinwell, Xavier Leroy and Anil Madhavapeddy)

- #2265: Add bytecomp/opcodes.mli
   (Mark Shinwell, review by Nicolas Ojeda Bar)

- #2268: Improve packing mechanism used for building compilerlibs modules
   into the Dynlink libraries
   (Mark Shinwell, Stephen Dolan, review by David Allsopp)

- #2277: Use newtype names as type variable names
   (Matthew Ryan)

- #2280: Don't make more Clambda constants after starting Cmmgen
   (Mark Shinwell, review by Vincent Laviron)

- #2281: Move some middle-end files around
   (Mark Shinwell)

- #2283: Add [is_prefix] and [find_and_chop_longest_common_prefix] to
   [Misc.Stdlib.List]
   (Mark Shinwell, review by Alain Frisch and Stephen Dolan)

- #2284: Add various utility functions to [Misc] and remove functions
   from [Misc.Stdlib.Option] that are now in [Stdlib.Option]
   (Mark Shinwell, review by Thomas Refis)

- #2286: Functorise [Consistbl]
   (Mark Shinwell, review by Gabriel Radanne)

- #2291: Add [Compute_ranges] pass
   (Mark Shinwell, review by Vincent Laviron)

- #2292: Add [Proc.frame_required] and [Proc.prologue_required].
   Move tail recursion label creation to [Linearize].  Correctly position
   [Lprologue] relative to [Iname_for_debugger] operations.
   (Mark Shinwell, review by Vincent Laviron)

- #2308: More debugging information on [Cmm] terms
   (Mark Shinwell, review by Stephen Dolan)

- #7878, #8542: Replaced TypedtreeIter with tast_iterator
   (Isaac "Izzy" Avram, review by Gabriel Scherer and Nicolás Ojeda Bär)

- #8598: Replace "not is_nonexpansive" by "maybe_expansive".
   (Thomas Refis, review by David Allsopp, Florian Angeletti, Gabriel 
Radanne,
    Gabriel Scherer and Xavier Leroy)

### Runtime system:

- #1725, #2279: Deprecate Obj.set_tag and Obj.truncate
   (Stephen Dolan, review by Gabriel Scherer, Damien Doligez and Xavier 
Leroy)

- #2075, #7729: rename _T macro used to support Unicode in the (Windows) 
runtime
   in order to avoid compiler warning
   (Nicolás Ojeda Bär, review by Gabriel Scherer and David Allsopp)

* #2240: Constify "identifier" in struct custom_operations
   (Cedric Cellier, review by Xavier Leroy)

- #2250: Remove extra integer sign-extension in compare functions
   (Stefan Muenzel, review by Xavier Leroy)

* #2293: Constify "caml_named_value"
   (Stephen Dolan, review by Xavier Leroy)

- #8607: Remove obsolete macros for pre-2002 MSVC support
   (Stephen Dolan, review by Nicolás Ojeda Bär and David Allsopp)

- #8656: Fix a bug in [caml_modify_generational_global_root]
   (Jacques-Henri Jourdan, review by Gabriel Scherer)

- #8787, #8788: avoid integer overflow in caml_output_value_to_bytes
   (Jeremy Yallop, report by Marcello Seri)

### Standard library:

- #2262: take precision (.<n>) and flags ('+' and ' ') into account
   in printf %F
   (Pierre Roux, review by Gabriel Scherer)

- #6148, #8596: optimize some buffer operations
   (Damien Doligez, reports by John Whitington and Alain Frisch,
    review by Jeremy Yallop and Gabriel Scherer)

### Other libraries:

- #2112: Fix Thread.yield unfairness with busy threads yielding to each
   other.
   (Andrew Hunter, review by Jacques-Henri Jourdan, Spiros Eliopoulos, 
Stephen
   Weeks, & Mark Shinwell)

- #7903, #2306: Make Thread.delay interruptible by signals again
   (Xavier Leroy, review by Jacques-Henri Jourdan and Edwin Török)

- #2248: Unix alloc_sockaddr: Fix read of uninitialized memory for an
   unbound Unix socket. Add support for receiving abstract (Linux) 
socket paths.
   (Tim Cuthbertson, review by Sébastien Hinderer and Jérémie Dimino)

- #2289: Delete the vmthreads library. This library was deprecated in 
4.08.0.
   (Jérémie Dimino)

- #2318: Delete the graphics library. This library is now available
   as a separate "graphics" package in opam. Its new home is:
   https://github.com/ocaml/graphics
   (Jérémie Dimino, review by Nicolas Ojeda Bar, Xavier Leroy and
    Sébastien Hinderer)

### Tools:

- #2221: ocamldep will now correctly allow a .ml file in an include 
directory
   that appears first in the search order to shadow a .mli appearing in 
a later
   include directory.
   (Nicolás Ojeda Bär, review by Florian Angeletti)

### Manual and documentation:

- #8757: Rename Pervasives to Stdlib in core library documentation.
   (Ian Zimmerman, review by David Allsopp)

- #7584, #8538: Document .cmt* files in the "overview" of ocaml{c,opt}
   (Oxana Kostikova, rewiew by Florian Angeletti)

- #8515: manual, precise constraints on reexported types
   (Florian Angeletti, review by Gabriel Scherer)

### Bug fixes:

- #7156, #8594: make top level use custom printers if they are available
   (Andrew Litteken, report by Martin Jambon, review by Nicolás Ojeda Bär,
    Thomas Refis, Armaël Guéneau, Gabriel Scherer, David Allsopp)
- #3249: ocamlmklib should reject .cmxa files
   (Xavier Leroy)
- #7937, #2287: fix uncaught Unify exception when looking for type
   declaration
   (Florian Angeletti, review by Jacques Garrigue)

- #2296: Fix parsing of hexadecimal floats with underscores in the exponent.
   (Hugo Heuzard and Xavier Leroy, review by Gabriel Scherer)

- #8610, #8613: toplevel printing, consistent deduplicated name for types
   (Florian Angeletti, review by Thomas Refis and Gabriel Scherer,
    reported by Xavier Clerc)

- #8635, #8636: Fix a bad side-effect of the -allow-approx option of
   ocamldep. It used to turn some errors into successes
   (Jérémie Dimino)

- #8701, #8725: Variance of constrained parameters causes principality 
issues
   (Jacques Garrigue, report by Leo White, review by Gabriel Scherer)

- #8777(partial): fix position information in some polymorphic variant
   error messages about missing tags
   (Florian Angeletti, review by Thomas Refis)

- #8779, more cautious variance computation to avoid missing cmis
   (Florian Angeletti, report by Antonio Nuno Monteiro, review by Leo White)

- #8800: Fix soundness bug in extension constructor inclusion
   (Leo White, review by Jacques Garrigue)

- #8810: Env.lookup_module: don't allow creating loops
   (Thomas Refis, report by Leo White, review by Jacques Garrigue)

- #8848: Fix x86 stack probe CFI information in caml_c_call and
   caml_call_gc
   (Tom Kelly, review by Xavier Leroy)

- #8864, #8865: Fix native compilation of left shift by (word_size - 1)
   (Vincent Laviron, report by Murilo Giacometti Rocha, review by Xavier 
Leroy)

- #8862, #8871: subst: preserve scopes
   (Thomas Refis, report by Leo White, review by Jacques Garrigue)

- #8921, #8924: Fix stack overflow with Flambda
   (Vincent Laviron, review by Pierre Chambart and Leo White,
    report by Aleksandr Kuzmenko)