[Caml-announce] Released: 4.03.0+beta1

Damien Doligez damien.doligez at inria.fr
Mon Feb 29 16:34:28 CET 2016

Dear OCaml users,

The release of OCaml version 4.03.0 is drawing near. We have
created a beta version for your testing pleasure. Please
use `opam switch 4.03.0+beta1` to install it, then test
your favourite software with it. Then let me know whether
it works for you.

We want to know about all bugs. Please report them at
  http://caml.inria.fr/mantis/bug_report_page.php .

This beta version is available as source code at these addresses:
and will (very soon) be available as an OPAM switch.

Happy hacking,

-- Damien Doligez for the OCaml team.

OCaml 4.03.0:

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

Language features:
- PR#5528: inline records for constructor arguments (Alain Frisch)
- PR#6220, PR#6403, PR#6437, PR#6801:
  Improved redundancy and exhaustiveness checks for GADTs.
  Namely, the redundancy checker now checks whether the uncovered pattern
  of the pattern is actually inhabited, exploding at most one wild card.
  This is also done for exhaustiveness when there is only one case.
  Additionally, one can now write unreachable cases, of the form,
  "pat -> .", which are treated by the redundancy check. (Jacques Garrigue)
- PR#6374: allow "_ t" as a short-hand for "(_, _, ..) t" for n-ary type
  constructors (Alain Frisch)
- PR#6714: allow [@@ocaml.warning] on most structure and signature items:
  values, modules, module types
- GPR#26: support for "(type a b)" as syntactic sugar for "(type a) (type b)"
  (Gabriel Scherer)
- GPR#42: short functor type syntax: "S -> T" for "functor (_ : S) -> T"
  (Leo White)
- GPR#88: allow field punning in object copying expressions:
    {< x; y; >} is sugar for {< x = x; y = y; >}
  (Jeremy Yallop)
- GPR#112: octal escape sequences for char and string literals
  (Rafaël Bocquet)
- GPR#167: allow to annotate externals' arguments and result types so
  they can be unboxed or untagged. Supports untagging int and unboxing
  int32, int64, nativeint and float.
  (Jérémie Dimino, Mark Shinwell)
- GPR240: replace special annotations on externals by attributes:
  * "float" is generalized to [@@unboxed]
  * "noalloc" becomes [@@noalloc]
  Deprecate "float" and "noalloc".
  (Jérémie Dimino)
- GPR#254: @ocaml.warn_on_literal_pattern attribute on constructors to
  warn when the argument is matches against a constant pattern.  This
  attribute is applied on predefined exception constructors which
  take an purely informational (with no stability guarantee) message.
  (Alain Frisch)
- GPR#268: hexadecimal notation for floating-point literals
  In OCaml source code, FP literals can be written using the hexadecimal
  notation 0x<mantissa in hex>p<exponent> from ISO C99.
  (Xavier Leroy)
- GPR#173: [@inline] and [@inlined] attributes (for function declarations
  and call sites respectively) to control inlining
  (Pierre Chambart, Mark Shinwell)
- PR#6806: Syntax shortcut for putting a type annotation on a record field
  (Valentin Gatien-Baron, review by Jérémie Dimino)
- PR#6806: Allow type annotations before the "->" in "fun <args> -> <expr>"
  (Valentin Gatien-Baron, review by Jérémie Dimino)
- GPR#282: change short-paths penalty heuristic to assign the same cost to
  idents containing double underscores as to idents starting with an underscore
  (Thomas Refis, Leo White)
- GPR#273: allow to get the extension slot of an extension constructor
  by writing [%extension_constructor <path>]
  (Jérémie Dimino)
- PR#6681 GPR#326: signature items are now accepted as payloads for
  extension and attributes, using the syntax [%foo: SIG ] or [@foo: SIG ].
  (Alain Frisch and Gabriel Radanne)
* GPR#342: Allow shortcuts for extension and attributes on all keywords.
  The attribute in "let[@foo] .. in .." is now attached to the value binding,
  not to the expression.
  (Gabriel Radanne)
* GPR#234: allow "[]" as a user-defined constructor. Demand parenthesis
  around "::" when using "::" as user-defined constructor.
  (Runhang Li, review by Damien Doligez)
- GPR#188: accept [@@immediate] attribute on type declarations to mark types
  that are represented at runtime by an integer
  (Will Crichton, reviewed by Leo White)

- PR#4080, PR#6537, PR#5333: fix stack overflow in the compiler when -pack'ing
  a module
  that includes a module of the same name (Alain Frisch)
- PR#4231, PR#5461: (interim solution) warning 31 is now fatal by default
- PR#4800: better compilation of tuple assignment (Gabriel Scherer and
  Alain Frisch)
- PR#5995: keep -for-pack into account to name exceptions; document -for-pack
  as mandatory for bytecode as well (Alain Frisch, report by Christophe
- PR#6400: better error message for '_' used as an expression
  (Alain Frisch, report by whitequark)
- PR#6501: harden the native-code generator against certain uses of "%identity"
  (Xavier Leroy, report by Antoine Miné).
- PR#6636: add --version option
- improve type-specialization of unapplied primitives
  (Frédéric Bour, review by Gabriel Scherer)
- PR#6737: fix Typedtree attributes on (fun x -> body) expressions
- PR#6679: fix pprintast printing of constraints in type declarations
- PR#6845: -no-check-prims to tell ocamlc not to check primitives in runtime
* PR#6865: remove special case for parsing "let _ = expr" in structures
  (Jérémie Dimino, Alain Frisch)
* PR#6438: Pattern guard disables exhaustiveness check
  (Alain Frisch)
- PR#6920: fix debug informations around uses of %apply or %revapply
  (Jérémie Dimino)
- PR#6939: Segfault with improper use of let-rec (Alain Frisch)
- PR#6943: native-code generator for POWER/PowerPC 64 bits, both in
  big-endian (ppc64) and little-endian (ppc64le) configuration.
  (Xavier Leroy, with inspiration from RedHat's unofficial ppc64 and ppc64le
- PR#6979: better code generation in x86-32 backend for copying floats to
  the stack (Marc Lasson, review by Xavier Leroy)
- PR#7018: fix missing identifier renaming during inlining (Alain Frisch,
  review by Xavier Leroy)
- PR#7026, GPR#288: remove write barrier for polymorphic variants without
  (Simon Cruanes)
- PR#7031: new warning, ambiguous guarded or-patterns (Luc Maranget,
  Gabriel Scherer, report by Martin Clochard and Claude Marché).
- PR#7067: Performance regression in the native compiler for long
  nested structures (Alain Frisch, report by Daniel Bünzli, review
  by Jacques Garrigue)
- PR#7097:  Strange syntax error message around illegal packaged module
  signature constraints (Alain Frisch, report by Jun Furuse)
- PR#7118, PR#7120: Bug fixed in stack unwinding metadata generation.
  Was a cause of crashes in GUI programs on OS X.
  (Bart Jacobs)
- GPR#17: some cmm optimizations of integer operations with constants
  (Stephen Dolan, review by Pierre Chambart)
- GPR#109: new unboxing strategy for float and int references (Vladimir Brankov,
  review by Alain Frisch)
- GPR#107: Prevent more unnecessary float boxing, especially in `if` and `match`
  (Vladimir Brankov, review by Alain Frisch)
- GPR#115: More precise typing of values at the C-- and Mach level,.
  (Xavier Leroy, review by Pierre Chambart)
- GPR#132: Flambda: new intermediate language and "middle-end" optimizers
  (Pierre Chambart, Mark Shinwell, Leo White)
- GPR#207: Colors in compiler messages (warnings, errors)
  (Simon Cruanes, review by Gabriel Scherer)
- GPR#258: more precise information on PowerPC instruction sizes
  (Pierre Chambart, Xavier Leroy)
- PR#7022, GPR#259: unbox float and boxed ints earlier, avoid second pass
  (Alain Frisch)
- PR#7064, GPR#316: allowing to mark compilation units and sub-modules as
  deprecated (Alain Frisch)
- GPR#263: improve code generation for if-equivalents of (&&) and (||)
  (Pierre Chambart)
- GPR#271: Fix incorrect mutability flag when records are built using "with"
  (Mark Shinwell)
- GPR#270: Make [transl_exception_constructor] generate [Immutable] blocks
  (Mark Shinwell)
- GPR#275: native-code generator for IBM z System running Linux.
  In memoriam Gene Amdahl, 1922-2015.
  (Bill O'Farrell, Tristan Amini, Xavier Leroy)
- GPR#282: relax short-paths safety check in presence of module aliases, take
  penalty into account while building the printing map.
  (Thomas Refis, Leo White)
- GPR#306: Instrument the compiler to debug performance regressions
  (Pierre Chambart)
- GPR#319: add warning for missing cmx files, and extend -opaque option to mli
  (Leo White)
- GPR#388: OCAML_FLEXLINK environment variable allows overriding flexlink
  command (David Allsopp)
- GPR#407: don't display the name of compiled .c files when calling the
  Microsoft C Compiler (same as the assembler).
  (David Allsopp)
- GPR#431: permit constant float arrays to be eligible for pattern match
  branch merging (Pierre Chambart)
- GPR#392: put all parsetree invariants in a new module Ast_invariants
  (Jérémie Dimino)
- GPR#455: provide more debugging information to Js_of_ocaml
  (Jérôme Vouillon)

Runtime system:
- PR#3612: allow allocating custom block with finalizers in the minor heap
  (Pierre Chambart)
- PR#6517: use ISO C99 types {,u}int{32,64}_t in preference to our homegrown
  types {,u}int{32,64}.
  (Xavier Leroy)
- PR#6760: closures evaluated in the toplevel can now be marshalled
  (whitequark, review by Jacques-Henri Jourdan)
- PR#6902, GPR#210: runtime emits a warning when finalizing an I/O channel
  which is still open (Alain Frisch, review by Damien Doligez);
  this is controlled by OCAMLRUNPARAM=W=1 or with Sys.enable_runtime_warnings.
- Signal handling: for read-and-clear, use GCC/Clang atomic builtins
  if available.  (Xavier Leroy)
- PR#6910, GPR#224: marshaling (output_value, input_value, et al)
  now support marshaled data bigger than 4 Gb.  (Xavier Leroy)
- GPR#226: select higher levels of optimization for GCC and Clang when
  compiling the run-time system and C stub code.  (Xavier Leroy)
- GPR#262: Multiple GC roots per compilation unit (Pierre Chambart, Mark
  Shinwell, review by Damien Doligez)
- GPR#325: Add v=0x400 flag to OCAMLRUNPARAM to display GC stats on exit (Louis
  Gesbert, review by Alain Frisch)
- GPR#297: Several changes to improve the worst-case GC pause time.
  (Damien Doligez, with help from Leo White and Francois Bobot)

Standard library:
- PR#1460, GPR#230: Array.map2, Array.iter2
  (John Christopher McAlpine)
- PR#5197, GPR#63: Arg: allow flags such as --flag=arg as well as --flag arg
  (Richard Jones)
- PR#6017, PR#7034, GPR#267: More efficient ifprintf implementation
  (Jeremy Yallop, review by Gabriel Scherer)
- PR#6296: Some documentation on the floating-point representations
    recognized by Pervasives.float_of_string
  (Xavier Leroy)
- PR#6316: Scanf.scanf failure on %u formats when reading big integers
  (Xavier Leroy, Benoît Vaugon)
- PR#6321: guarantee that "hypot infinity nan = infinity"
  (for conformance with ISO C99)  (Xavier Leroy)
- PR#6390, GPR#36: expose Sys.{int_size,max_wosize} for improved js_of_ocaml
  portability (Hugo Heuzard)
- PR#6449: Add Map.union (Alain Frisch)
* PR#6494: Add equal function in modules
  Bytes, Char, Digest, Int32, Int64, Nativeint, and String
  (Romain Calascibetta)
* PR#6524, GPR#79: Filename: Optional ?perms argument to open_temp_file
  (Daniel Bünzli, review by Jacques-Pascal Deplaix)
* PR#6525, GPR#80: Add Uchar module to the standard library
  (Daniel Bünzli, review by Yoriyuki Yamagata and Damien Doligez)
- PR#6577: improve performance of %L, %l, %n, %S, %C format specifiers
  (Alain Frisch)
- PR#6585: fix memory leak in win32unix/createprocess.c
- PR#6649, GPR#222: accept (int_of_string "+3")
  (Christopher McAlpine)
- PR#6645, GPR#174: Guarantee that Set.add, Set.remove, Set.filter
  return the original set if no change is required (Alain Frisch,
  Mohamed Iguernlala)
- GPR#175: Guarantee that Map.add, Map.remove, Map.filter
  return the original map if no change is required.
  (Mohamed Iguernlala)
- PR#6694, PR#6695: deprecate functions using ISO-8859-1 character set
  in Char, Bytes, String and provide alternatives using US-ASCII.
- GPR#164: more efficient (branchless) implementation of Pervasives.compare
  specialized at type 'float'.
  (Vladimir Brankov)
- GPR#201: generalize types of Printf.{ifprintf,ikfprintf}
  (Maxence Guesdon)
- GPR#216: add the missing POSIX.1-2001 signals in Sys
  (Guillaume Bury)
- GPR#239: remove type-unsafe code from Stream
  (Pierre Chambart, review by Gabriel Scherer and Jeremy Yallop)
- GPR#250: Check for negative start element in Array.sub
  (report and fix by Jeremy Yallop)
- GPR#265: new implementation of Queue avoiding Obj.magic
  (Jérémie Dimino)
- GPR#268, GPR#303: '%h' and '%H' modifiers for printf and scanf to
  support floating-point numbers in hexadecimal notation
  (Xavier Leroy, Benoît Vaugon)
- GPR#272: Switch classify_float to [@@unboxed] (Alain Frisch)
- Improve speed of classify_float by not going through fpclassify()
  (Alain Frisch, Xavier Leroy)
- GPR#277: Switch the following externals to [@@unboxed]:
  * {Nativeint,Int32,Int64}.{of,to}_float
  * Int{32,64}.float_of_bits
  * Int{32,64}.bits_of_float
  (Jérémie Dimino)
- GPR#281: Switch the following externals to [@@unboxed]:
  * Sys.time (and [@@noalloc])
  * Pervasives.ldexp (and [@@noalloc])
  * Pervasives.compare for float, nativeint, int32, int64.
  (François Bobot)
- PR#3622, GPR#195: add function Stack.fold
  (Simon Cruanes)
- GPR#329: Add exists, for_all,  mem and memq functions in Array
  (Bernhard Schommer)
- GPR#337: Add [Hashtbl.filter_map_inplace] (Alain Frisch)
- GPR#356: Add [Format.kasprintf] (Jérémie Dimino, Mark Shinwell)
- GPR#22: Add the Ephemeron module that implements ephemerons and weak
  hash table (François Bobot, review by Damien Doligez, Daniel Bünzli,
  Alain Frisch, Pierre Chambart)

Type system:
- PR#5545: Type annotations on methods cannot control the choice of abbreviation
* PR#6465: allow incremental weakening of module aliases (Jacques Garrigue).
  This is done by adding equations to submodules when expanding aliases.
  In theory this may be incompatible is some corner cases defining a module
  type through inference, but no breakage known on published code.
- PR#6593: Functor application in tests/basic-modules fails after commit 15405

Toplevel and debugger:
- PR#6113: Add descriptions to directives, and display them via #help
  (Nick Giannarakis, Berke Durak, Francis Southern and Gabriel Scherer)
- PR#6396: Warnings-as-errors not properly flushed in the toplevel
  (Alain Frisch)
- PR#6468: toplevel now supports backtraces if invoked with OCAMLRUNPARAM=b
  (whitequark and Jake Donham,
   review by Gabriel Scherer and Jacques-Henri Jourdan)
- PR#6935, GPR#298: crash in debugger when load_printer is given a directory
  (Junsong Li, review by Gabriel Scherer)
- PR#6401: use proper error reporting for toplevel's environment
  initialization (Gabriel Scherer)
- PR#7081: report preprocessor warnings in the toplevel
  (Valentin Gatien-Baron, review by Jérémie Dimino)
- PR#7098: Loss of ppx context in toplevel after an exception
  (Alain Frisch, report by whitequark)
- PR#7101: The toplevel does not close in_channel for libraries specified on
  its command line (Alain Frisch)
- PR#7119: ocaml doesn't respect [@@@warning] (Alain Frisch, report by
  Gabriel Radanne)

Other libraries:
* Unix library: channels created by Unix.in_channel_of_descr or
  Unix.out_channel_of_descr no longer support text mode under Windows.
  Calling [set_binary_mode_{in,out} chan false] on these channels
  now causes an error.
- PR#4023 and GPR#68: add Unix.sleepf (sleep with sub-second resolution)
  (Evgenii Lepikhin and Xavier Leroy)
* Protect Unix.sleep against interruptions by handled signals.
  Before, a handled signal could cause Unix.sleep to return early.
  Now, the sleep is restarted until the given time is elapsed.
  (Xavier Leroy)
* PR#6120: implement Unix.symlink and Unix.readlink on Windows. Unix.symlink has
  a new optional argument to_dir (ignored on non-native Windows platforms). stat
  functions reimplemented to avoid buggy Microsoft CRT implementations (native
  Windows only)
- PR#6263: add kind_size_in_bytes and size_in_bytes functions
  to Bigarray module.
  (Runhang Li, review by Mark Shinwell)
- PR#6289: Unix.utimes uses the current time only if both arguments
    are exactly 0.0.  Also, use sub-second resolution if available.
  (Xavier Leroy, report by Christophe Troestler)
- PR#6896: serious reimplementation of Big_int.float_of_big_int and
  Ratio.float_of_ratio, ensuring that the result is correctly rounded.
  (Xavier Leroy)
- PR#6989: in Str library, make sure that all \(...\) groups are binding
    and can be consulted with Str.matched_group.  There used to be
    a limitation to 32 binding groups.
  (Xavier Leroy)
- PR#7013: spurious wake-up in the Event module
  (Xavier Leroy)
- PR#7024: in documentation of Str regular expressions, clarify what
    "end of line" means for "^" and "$" regexps.

- GPR#286: add support for module aliases
  (jacques Garrigue)

- GPR#302: The OCaml reference manual is now included in the manual/
  subdirectory of the main OCaml source repository. Contributions to
  the manual are warmly welcome.
  (François Bobot, review by Florian Angeletti)
- MPR#6676: ongoing simplification of the "Language Extensions" section
  (Alain Frisch, John Whitington)
- MPR#7092, GPR#379: Add missing documentation for new 4.03 features
  (Florian Angeletti)
- MPR#7109, GPR#380: Fix bigarray documentation layout
  (Florian Angeletti, Leo White)

Bug fixes:
- PR#3612: memory leak in bigarray read from file
  (Pierre Chambart, report by Gary Huber)
* PR#4166, PR#6956: force linking when calling external C primitives
  (Jacques Garrigue, reports by Markus Mottl and Christophe Troestler)
* PR#4466, PR#5325: under Windows, concurrent read and write operations
    on the same socket could block unexpectedly.  Fixed by keeping sockets
    in asynchronous mode rather than creating them in synchronous mode.
  (Xavier Leroy)
* PR#4539: change exception string raised when comparing functional values
  (Nicolas Braud-Santoni, report by Eric Cooper)
- PR#4832: Filling bigarrays may block out runtime
  (Markus Mottl)
- PR#5663: program rejected due to nongeneralizable type variable that
    appears nowhere
  (Jacques Garrigue, report by Stephen Weeks)
- PR#5780: Strange type variable names in error messages (GADTs)
    (only made the names more informative)
  (Jacques Garrigue, report by Sebastien Furic)
- PR#5887: move the byterun/*.h headers to byterun/caml/*.h to avoid header
    name clashes
  (Jérôme Vouillon and Adrien Nader and whitequark)
* PR#6081: ocaml should add script's directory to search path, not current
  (Thomas Leonard and Damien Doligez)
- PR#6108, PR#6802: fail cleanly if dynlink.cma or ocamltoplevel.cma
    are loaded inside the toplevel loop.
  (Xavier Leroy)
- PR#6171: Error message confusing when a type escapes its scope.
- PR#6340: Incorrect handling of \r when processing "Windows" source files
  (Damien Doligez, report by David Allsopp)
- PR#6342: Incorrect error message when type constraints differ
  (Alain Frisch, report by Philippe Wang)
* PR#6521: {Bytes,Char,String}.escaped are locale-dependent
  (Damien Doligez, report by Jun Furuse)
- PR#6526: ocamllex warning: unescaped newline in comment string
  (Damien Doligez, report by user 'dhekir')
- PR#6341: ocamldoc -colorize-code adds spurious <br> tags to <pre> blocks
- PR#6560: Wrong failure message for {Int32,Int64,NativeInt}.of_string
  (Maxime Dénès and Gabriel Scherer)
- PR#6648: show_module should indicate its elision
- PR#6650: Cty_constr not handled correctly by Subst
- PR#6651: Failing component lookup
* PR#6664: Crash when finalising lazy values of the wrong type.
  (Damien Doligez)
- PR#6672: Unused variance specification allowed in with constraint
- PR#6744: Univars can escape through polymorphic variants (partial fix)
- PR#6752: Extensible variant types and scope escaping
- PR#6762: improve warning 45 in presence of re-exported type definitions
  (Alain Frisch, report by Olivier Andrieu)
- PR#6776: Failure to kill the "tick" thread, segfault when exiting the runtime
- PR#6780: Poor error message for wrong -farch and -ffpu options (ocamlopt, ARM)
- PR#6805: Duplicated expression in case of hole in a non-failing switch.
  (Luc Maranget)
- PR#6808: the parsing of OCAMLRUNPARAM is too lax
  (Damien Doligez)
- PR#6874: Inefficient code generated for module function arguments
- PR#6888: The list command of ocamldebug uses the wrong file
  (Damien Doligez, report by Pierre-Marie Pédrot)
- PR#6897: Bad error message for some pattern matching on extensible variants
- PR#6899: Optional parameters and non generalizable type variables
  (Thomas Refis and Leo White)
- PR#6907: Stack overflow printing error in class declaration
- PR#6931: Incorrect error message
- PR#6938: fix regression on "%047.27{l,L,n}{d,i,x,X,o,u}"
  (Benoît Vaugon, report by Arduino Cascella)
- PR#6944: let module X = Path in … is not typed as a module alias
  (Jacques Garrigue, report by def)
- PR#6945 and GPR#227: protect Sys and Unix functions against string
    arguments containing the null character '\000'
  (c-cube and Xavier Leroy, report by Daniel Bünzli)
- PR#6946: Uncaught exception with wrong type for "%ignore"
- PR#6954: Infinite loop in type checker with module aliases
- PR#6972, GPR#276: 4.02.3 regression on documentation comments in .cmt files
  (Leo White, report by Olivier Andrieu)
- PR#6977: String literals in comments interpret escape sequences
  (Damien Doligez, report by Daniel Bünzli and David Sheets)
- PR#6980: Assert failure from polymorphic variants and existentials
- PR#6981: Ctype.Unify(_) with associated functor arg refering to previous one
- PR#6982: unexpected type error when packing a module alias
- PR#6985: `module type of struct include Bar end exposes
           %s#row when Bar contains private row types
- PR#6992: Segfault from bug in GADT/module typing
- PR#6993: Segfault from recursive modules violating exhaustiveness assumptions
- PR#6998: Typer fails reading unnecessary cmis with -no-alias-deps and -w -49
  (Leo White, report by Valentin Gatien-Baron)
- PR#7003: String.sub causes segmentation fault
  (Damien Doligez, report by Radek Micek)
- PR#7008: Fatal error in ocamlc with empty compilation unit name
  (Damien Doligez, report by Cesar Kunz)
- PR#7012: Variable name forgotten when it starts with a capital letter
  (Jacques Garrigue, Gabriel Scherer,
   report by Thomas Leonard and Florian Angeletti)
- PR#7016: Stack overflow in GADT typing
- PR#7030: libasmrun_shared.so fails to build on SPARC Solaris
  (report and fix by Patrick Star)
- PR#7036: Module alias is not taken into account when checking module
  type compatibility (in a class type) (Jacques Garrigue)
- PR#7037: more reproducible builds, don't put temp file names into objects
  (Xavier Leroy)
- PR#7038: out of memory condition in caml_io_mutex_lock
  (Xavier Leroy, report by Marc Lasson)
- PR#7039: Unix.getsockname returns garbage for unnamed PF_UNIX sockets
  (Xavier Leroy)
- PR#7042 and GPR#295: CSE optimization confuses the FP literals +0.0 and -0.0
  (Xavier Leroy)
- PR#7075: Fix repetitions in ocamldoc generated documentation
  (Florian Angeletti)
- PR#7082: Object type in recursive module's `with` annotation
- PR#7108: ocamldoc, have -html preserve custom/extended html generators
  (Armaël Guéneau)
- PR#7096: ocamldoc uses an incorrect subscript/superscript style
- PR#7115: shadowing in a branch of a GADT match breaks unused variable
  warning (Alain Frisch, report by Valentin Gatien-Baron)
- PR#7133: Jump labels in assembly end up as symbols in the executable on OS X
  (Bart Jacobs)
- PR#7135: only warn about ground coercions in -principal mode
  (Jacques Garrigue, report by Jeremy Yallop)
- GPR#205: Clear caml_backtrace_last_exn before registering as root
  (report and fix by Frederic Bour)
- GPR#220: minor -dsource error on recursive modules
  (Hongbo Zhang)
- GPR#228: fix a dangling internal pointer in (bytecode )debug_info
  (Gabriel Scherer and Mark Shinwell and Xavier Leroy)
- GPR#233: Make CamlinternalMod.init_mod robust to optimization
  (Pierre Chambart, Mark Shinwell)
- GPR#249: fix a few hardcoded ar commands
  (Daniel Bünzli)
- GPR#251: fix cross-compilation with ocamldoc enabled
- GPR#280: Fix stdlib dependencies for .p.cmx (Pierre Chambart,
  Mark Shinwell)
- GPR#283: Fix memory leaks in intern.c when OOM is raised
  (Marc Lasson, review by Alain Frisch)
- GPR#22: Fix the cleaning of weak pointers. In very rare cases
  accessing a value during the cleaning of the weak pointers could
  result in the value being removed from one weak arrays and kept in
  another one. That breaks the property that a value is removed from a
  weak pointer only when it is dead and garbage collected. (François
  Bobot, review by Damien Doligez)
- GPR#313: Prevent quadratic cases in CSE
  (Pierre Chambart, review by Xavier Leroy)
- PR#6795, PR#6996: Make ocamldep report errors passed in
  [%ocaml.error] extension points
  (Jérémie Dimino)
- GPR#355: make ocamlnat build again
  (Jérémie Dimino, Thomas Refis)
- GPR#405: fix compilation under Visual Studio 2015
  (David Allsopp)
- GPR#441: better type error location in presence of type constraints
  (Thomas Refis, report by Arseniy Alekseyev)
- PR#7111: reject empty let bindings instead of printing incorrect syntax
  (Jérémie Dimino)

Features wishes:
- PR#4518, GPR#29: change location format for reporting errors in ocamldoc
  (Sergei Lebedev)
- PR#4714: List.cons
- PR#5418 (comments) : generate dependencies with $(CC) instead of gcc
- PR#6167: OCAMLPARAM support for disabling PIC generation ("pic=0")
  (Gabor Pali)
- PR#6367: introduce Asttypes.arg_label to encode labelled arguments
- PR#6452, GPR#140: add internal suport for custom printing formats
  (Jérémie Dimino)
- PR#6611: remove the option wrapper on optional arguments in the syntax tree
- PR#6635: support M.[], M.(), M.{< >} and M.[| |]
  (Jeremy Yallop, review by Gabriel Radanne)
- PR#6691: install .cmt[i] files for stdlib and compiler-libs
  (David Sheets, request by Gabriel Radanne)
- PR#6722: compatibility with x32 architecture (x86-64 in ILP32 mode).
  ocamlopt is not supported, but bytecode compiles cleanly.
- PR#6742: remove duplicate virtual_flag information from Tstr_class
- PR#6719: improve Buffer.add_channel when not enough input is available
  (Simon Cruanes)
* PR#6816: reject integer and float literals directly followed by an identifier.
  This was prevously read as two separate tokens.
  [let abc = 1 in (+) 123abc] was accepted and is now rejected.
  (Hugo Heuzard)
- PR#6876: improve warning 6 by listing the omitted labels.
  (Eyyüb Sari)
- PR#6924: tiny optim to avoid some spilling of floats in x87
  (Alain Frisch)
- GPR#111: `(f [@taillcall]) x y` warns if `f x y` is not a tail-call
  (Simon Cruanes)
- GPR#118: ocamldep -allow-approx: fallback to a lexer-based approximation
  (Frédéric Bour)
- GPR#137: add untypeast.ml (in open recursion style) to compiler-libs
  (Gabriel Radanne)
- GPR#142: add a CAMLdrop macro for undoing CAMLparam*/CAMLlocal*
- GPR#145: speeedup bigarray access by optimizing Cmmgen.bigarray_indexing
  (Vladimir Brankov, review by Gabriel Scherer)
- GPR#147: [type 'a result = Ok of 'a | Error of 'b] in Pervasives
  (Yaron Minsky)
- GPR#156, GPR#279: optimize caml_frame_descriptors realloc (dynlink speedup)
  (Pierre Chambart, Alain Frisch,
   review by François Bobot, Xavier Leroy and Damien Doligez)
- GPR#191: Making gc.h and some part of memory.h public
  (Thomas Refis)
- GPR#196: Make [Thread.id] and [Thread.self] [noalloc]
  (Clark Gaebel)
- GPR#165, GPR#221: fix windows compilation warnings
  (Bernhard Schommer, Gabriel Scherer, report by Alain Frisch)
- GPR#189: Added .dylib and .so as extensions for ocamlmklib
  (Edgar Aroutiounian, whitequark)
- GPR#237: a CONTRIBUTING document
  (François Bobot, Gabriel Scherer, review by Xavier Leroy)
- GPR#245: remove a few remaining French comments
  (Florian Angeletti)
- GPR#252: improve build instructions in MSVC Windows README
  (Philip Daian)
* GPR#170: Parse arbitrary precision integers.
  Accept a single [A-Za-z] as modifier for integers (generalizing 'l','L','n')
  and floats.
  May cause breakage (ie. ppx preprocessor) because of changes in the parsetree.
  This changes PR#6816 a little bit by reading the literal [123a] as a single
  token that can later be rewritten by a ppx preprocessor.
  (Hugo Heuzard)
- GPR#308: add experimental support for NetBSD/arm (verified on RaspberryPi)
  (Rich Neswold)
- GPR#335: Type error messages specify if a type is abstract
  because no corresponding cmi could be found. (Hugo Heuzard)
- GPR#365: prevent printing just a single type variable on one side
  of a type error clash. (Hugo Heuzard)
- GPR#383: configure: define _ALL_SOURCE for build on AIX7.1
- GPR#401: automatically retry failed test directories in the testsuite
  (David Allsopp)
- GPR#451: an optional 'parallel' target in testsuite/Makefile using the
  GNU parallel tool to run tests in parallel.
  (Gabriel Scherer)

Build system:
- GPR#388: FlexDLL added as a Git submodule and bootstrappable with the compiler
  (David Allsopp)

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