[ANN] OCaml 4.05.0 released

Cross posting from the OCaml mailing list :slight_smile:

Dear OCaml users,

We have the pleasure of celebrating the birthdays of Simone Veil and Ernö Rubik
by announcing the release of OCaml version 4.05.0.

It is available as an OPAM switch, or as a source
download here: < https://caml.inria.fr/pub/distrib/ocaml-4.05/ >

Happy hacking,

– Damien Doligez for the OCaml team.

OCaml 4.05.0 (13 Jul 2017):

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

Code generation and optimizations:

  • PR#7201, GPR#954: Correct wrong optimisation of "0 / "
    and "0 mod " in the case when was a non-constant
    evaluating to zero
    (Mark Shinwell, review by Gabriel Scherer, Leo White and Xavier Leroy)

  • PR#7357, GPR#832: Improve compilation time for toplevel
    include(struct … end : sig … end)
    (Alain Frisch, report by Hongbo Zhang, review by Jacques Garrigue)

  • PR#7533, GPR#1173: Correctly perform side effects for certain
    cases of “/” and “mod”
    (Mark Shinwell, report by Jan Mitgaard)

  • GPR#504: Instrumentation support for fuzzing with afl-fuzz.
    (Stephen Dolan, review by Alain Frisch, Pierre Chambart, Mark
    Shinwell, Gabriel Scherer and Damien Doligez)

  • GPR#863, GPR#1068, GPR#1069: Optimise matches with constant
    results to lookup tables.
    (Stephen Dolan, review by Gabriel Scherer, Pierre Chambart,
    Mark Shinwell, and bug report by Gabriel Scherer)

  • GPR#1150: Fix typo in arm64 assembler directives
    (KC Sivaramakrishnan)

Runtime system:

  • PR#385, GPR#953: Add caml_startup_exn
    (Mark Shinwell)

  • PR#7423, GPR#946: expose new exception-raising functions
    void caml_{failwith,invalid_argument}_value(value msg)
    in addition to
    void caml_{failwith,invalid_argument}(char const *msg).
    The previous functions would not free their message argument, so
    were inconvient for dynamically-allocated messages; the messages
    passed to the new functions are handled by the garbage collector.
    (Gabriel Scherer, review by Mark Shinwell, request by Immanuel Litzroth)

  • PR#7557, GPR#1213: More security for getenv
    (Damien Doligez, reports by Seth Arnold and Eric Milliken, review by
    Xavier Leroy, David Allsopp, Stephen Dolan, Hannes Mehnert)

  • GPR#795: remove 256-character limitation on Sys.executable_name
    (Xavier Leroy)

  • GPR#891: Use -fno-builtin-memcmp when building runtime with gcc.
    (Leo White)

Type system:

  • PR#6608, GPR#901: unify record types when overriding all fields
    (Tadeu Zagallo and Gabriel Scherer, report by Jeremy Yallop,
    review by David Allsopp, Jacques Garrigue)
  • PR#7414, GPR#929: Soundness bug with non-generalized type variables and
    (compatibility: some code using module-global mutable state will
    fail at compile-time and is fixed by adding extra annotations;
    see the Mantis and Github discussions.)
    (Jacques Garrigue, report by Leo White)

Compiler user-interface and warnings:

  • PR#7050, GPR#748 GPR#843 GPR#864: new -args/-args0 <file> parameters to
    provide extra command-line arguments in a file – see documentation.
    User programs may implement similar options using the new Expand
    constructor of the Arg module.
    (Bernhard Schommer, review by Jérémie Dimino, Gabriel Scherer
    and Damien Doligez, discussion with Alain Frisch and Xavier Leroy,
    feature request from the Coq team)

  • PR#7137, GPR#960: “-open” command line flag now accepts
    a module path (not a module name)
    (Arseniy Alekseyev and Leo White)

  • PR#7172, GPR#970: add extra (ocamlc -config) options
    int_size, word_size, ext_exe
    (Gabriel Scherer, request by Daniel Bünzli)

  • PR#7315, GPR#736: refine some error locations
    (Gabriel Scherer and Alain Frisch, report by Matej Košík)

  • PR#7473, GPR#1025: perform proper globbing for command-line arguments on
    (Jonathan Protzenko)

  • PR#7479: make sure “ocamlc -pack” is only given .cmo and .cmi files,
    and that “ocamlopt -pack” is only given .cmx and .cmi files.
    (Xavier Leroy)

  • GPR#796: allow compiler plugins to declare their own arguments.
    (Fabrice Le Fessant)

  • GPR#829: better error when opening a module aliased to a functor
    (Alain Frisch)

  • GPR#911: ocamlc/ocamlopt do not pass warnings-related options to C
    compiler when called to compile third-party C source files
    (Sébastien Hinderer, review by Adrien Nader and David Allsopp)

  • GPR#915: fix -dsource (pprintast.ml) bugs
    (Runhang Li, review by Alain Frisch)

  • GPR#933: ocamlopt -p now reports an error on platforms that do not
    support profiling with gprof; dummy profiling libraries are no longer
    installed on such platforms.
    This can be tested with ocamlopt -config
    (Sébastien Hinderer)
  • GPR#1009: “ocamlc -c -linkall” and “ocamlopt -c -linkall” can now be used
    to set the “always link” flag on individual compilation units. This
    controls linking with finer granularity than “-a -linkall”, which sets
    the “always link” flag on all units of the given library.
    (Xavier Leroy)

  • GPR#1015: add option “-plugin PLUGIN” to ocamldep too. Use compilerlibs
    to build ocamldep.
    (Fabrice Le Fessant)

  • GPR#1027: various improvements to -dtimings, mostly including time
    spent in subprocesses like preprocessors
    (Valentin Gatien-Baron, review by Gabriel Scherer)

  • GPR#1098: the compiler now takes the boolean “OCAML_COLOR” environment
    variable into account if “-color” is not provided. This allows users
    to override the default behaviour without modifying invocations of ocaml
    (Hannes Mehnert, Guillaume Bury,
    review by Daniel Bünzli, Gabriel Scherer, Damien Doligez)

Standard library:

  • PR#6975, GPR#902: Truncate function added to stdlib Buffer module
    (Dhruv Makwana, review by Alain Frisch and Gabriel Scherer)

  • PR#7279, GPR#710: Weak.get_copy Ephemeron.*_copy doesn’t copy
    custom blocks anymore
    (François Bobot, Alain Frisch, bug reported by Martin R. Neuhäußer,
    review by Thomas Braibant and Damien Doligez)

  • GPR#760: Add a functions List.compare_lengths and
    List.compare_length_with to avoid full list length computations
    (Fabrice Le Fessant, review by Leo White, Josh Berdine and Gabriel Scherer)

  • GPR#778: Arg: added option Expand that allows to expand a string
    argument to a string array of new arguments
    (Bernhard Schommer, review by Gabriel Scherer and Jérémie Dimino)

  • GPR#849: Expose a Spacetime.enabled value
    (Leo White)

  • GPR#885: Option-returning variants of stdlib functions
    (Alain Frisch, review by David Allsopp and Bart Jacobs)

  • GPR#869: Add find_first, find_first_opt, find_last, find_last_opt to
    maps and sets. Find the first or last binding or element
    satisfying a monotonic predicate.
    (Gabriel de Perthuis, with contributions from Alain Frisch, review by
    Hezekiah M. Carty and Simon Cruanes, initial report by Gerd Stolpmann)

  • GPR#875: Add missing functions to ArrayLabels, BytesLabels,
    ListLabels, MoreLabels, StringLabels so they are compatible with
    non-labeled counterparts. Also add missing @@ocaml.deprecated attributes
    in StringLabels and BytesLabels.
    (Roma Sokolov, review by Gabriel Scherer, Jacques Garrigue,
    Gabriel Radanne, Alain Frisch)

  • GPR#999: Arg, do not repeat the usage message thrice when reporting an error
    (this was a regression in 4.03)
    (Florian Angeletti, review by Gabriel Scherer)

  • GPR#1042: Fix escaping of command-line arguments in
    Unix.create_process{,_env} under Windows. Arguments with tabs should now
    be received verbatim by the child process.
    (Nicolas Ojeda Bar, Andreas Hauptmann review by Xavier Leroy)

Debugging and profiling:

  • PR#7258: ocamldebug’s “install_printer” command had problems with
    module aliases
    (Xavier Leroy)

  • GPR#378: Add [Printexc.raise_with_backtrace] to raise an exception using
    an explicit backtrace
    (François Bobot, review by Gabriel Scherer, Xavier Leroy, Damien Doligez,
    Frédéric Bour)

Manual and documentation:

  • PR#6597, GPR#1030: add forward references to language extensions
    that extend non-terminal symbols in the language reference section.
    (Florian Angeletti, review by Gabriel Scherer)

  • PR#7497, GPR#1095: manual, enable numbering for table of contents
    (Florian Angeletti, request by Daniel Bünzli)

  • PR#7539, GPR#1181: manual, update dead links in ocamldoc chapter
    (Florian Angeletti)

  • GPR#633: manpage and manual documentation for the -opaque option
    (Konstantin Romanov, Gabriel Scherer, review by Mark Shinwell)

  • GPR#751, GPR#925: add a HACKING.adoc file to contain various
    tips and tricks for people hacking on the repository. See also
    CONTRIBUTING.md for advice on sending contributions upstream.
    (Gabriel Scherer and Gabriel Radanne, review by David Allsopp,
    inspired by John Whitington)

  • GPR#916: new tool lintapidiff, use it to update the manual with
    @since annotations for API changes introduced between 4.00-4.05.
    (Edwin Török, review by Gabriel Scherer, discussion with Alain Frisch,
    David Allsopp, Sébastien Hinderer, Damien Doligez and Xavier Leroy)

  • GPR#939: activate the caml_example environment in the language
    extensions section of the manual. Convert some existing code
    examples to this format.
    (Florian Angeletti)

  • GPR#1082: clarify that the use of quoted string for preprocessed
    foreign quotations still requires the use of an extension node
    [%foo …] to mark non-standard interpretation.
    (Gabriel Scherer, request by Matthew Wahab in GPR#1066,
    review by Florian Angeletti)

Other libraries:

  • PR#7158: Event.sync, Mutex.create, Condition.create cause too many GCs.
    The fix is to no longer consider mutexes and condition variables
    as rare kernel resources.
    (Xavier Leroy)

  • PR#7264: document the different behaviors of Unix.lockf under POSIX
    and under Win32.
    (Xavier Leroy, report by David Allsopp)

  • PR#7339, GPR#787: Support the ‘0 dimension’ case for bigarrays
    (see Bigarray documentation)
    (Laurent Mazare,
    review by Gabriel Scherer, Alain Frisch and Hezekiah M. Carty)

  • PR#7342, GPR#797: fix Unix.read on pipes with no data left on Windows
    it previously raised an EPIPE error, it now returns 0 like other OSes
    (Jonathan Protzenko, review by Andreas Hauptmann and Damien Doligez)
  • GPR#650: in the Unix library, add ?cloexec:bool optional arguments to
    functions that create file descriptors (dup, dup2, pipe, socket,
    socketpair, accept). Implement these optional arguments in the
    most atomic manner provided by the operating system to set (or clear)
    the close-on-exec flag at the same time the file descriptor is created,
    reducing the risk of race conditions with exec or create_process
    calls running in other threads, and improving security. Also: add a
    O_KEEPEXEC flag for openfile by symmetry with O_CLOEXEC.
    (Xavier Leroy, review by Mark Shinwell, David Allsopp and Alain Frisch,
    request by Romain Beauxis)

  • GPR#996: correctly update caml_top_of_stack in systhreads
    (Fabrice Le Fessant)


  • PR#7060, GPR#1035: Print exceptions in installed custom printers
    (Tadeu Zagallo, review by David Allsopp)


  • PR#5163: ocamlobjinfo, dump globals defined by bytecode executables
    (Stéphane Glondu)

  • PR#7333: ocamldoc, use the first sentence of text file as
    a short description in overviews.
    (Florian Angeletti)

  • GPR#848: ocamldoc, escape link targets in HTML output
    (Etienne Millon, review by Gabriel Scherer, Florian Angeletti and
    Daniel Bünzli)

  • GPR#986: ocamldoc, use relative paths in error message
    to solve ocamlbuild+doc usability issue (ocaml/ocamlbuild#79)
    (Gabriel Scherer, review by Florian Angeletti, discussion with Daniel Bünzli)

  • GPR#1017: ocamldoc, add an option to detect code fragments that could be
    transformed into a cross-reference to a known element.
    (Florian Angeletti, review and suggestion by David Allsopp)

  • clarify ocamldoc text parsing error messages
    (Gabriel Scherer)

Compiler distribution build system:

  • PR#7377: remove -std=gnu99 for newer gcc versions
    (Damien Doligez, report by ygrek)

  • PR#7452, GPR#1228: tweak GCC options to try to avoid the
    Skylake/Kaby lake bug
    (Damien Doligez, review by David Allsopp, Xavier Leroy and Mark Shinwell)

  • GPR#693: fail on unexpected errors or warnings within caml_example
    (Florian Angeletti)

  • GPR#803: new ocamllex-based tool to extract bytecode compiler
    opcode information from C headers.
    (Nicolas Ojeda Bar)

  • GPR#827: install missing mli and cmti files, new make target
    install-compiler-sources for installation of compiler-libs ml files
    (Hendrik Tews)

  • GPR#887: allow -with-frame-pointers if clang is used as compiler on Linux
    (Bernhard Schommer)

  • GPR#898: fix locale-dependence of primitive list order,
    detected through reproducible-builds.org.
    (Hannes Mehnert, review by Gabriel Scherer and Ximin Luo)

  • GPR#907: Remove unused variable from the build system
    (Sébastien Hinderer, review by whitequark, Gabriel Scherer, Adrien Nader)

  • GPR#911: Clarify the use of C compiler related variables in the build system.
    (Sébastien Hinderer, review by Adrien Nader, Alain Frisch, David Allsopp)

  • GPR#919: use clang as preprocessor assembler if clang is used as compiler
    (Bernhard Schommer)

  • GPR#927: improve the detection of hashbang support in the configure script
    (Armaël Guéneau)

  • GPR#932: install ocaml{c,lex}->ocaml{c,lex}.byte symlink correctly
    when the opt target is built but opt.opt target is not.
    (whitequark, review by Gabriel Scherer)

  • GPR#935: allow build in Android’s termux
    (ygrek, review by Gabriel Scherer)

  • GPR#984: Fix compilation of compiler distribution when Spacetime
    (Mark Shinwell)

  • GPR#991: On Windows, fix installation when native compiler is not
    (Sébastien Hinderer, review by David Allsopp)

  • GPR#1033: merge Unix and Windows build systems in the root directory
    (Sébastien Hinderer, review by Damien Doligez and Adrien Nader)

  • GPR#1047: Make .depend files generated for C sources more portable
    (Sébastien Hinderer, review by Xavier Leroy and David Allsopp)

  • GPR#1076: Simplify ocamlyacc’s build system
    (Sébastien Hinderer, review by David Allsopp)

Compiler distribution build system: Makefile factorization

The compiler distribution build system (the set of Makefiles used to
build the compiler distribution) traditionally had separate Makefiles
for Unix and Windows, which lead to some amount of duplication and
subtle differences and technical debt in general – for people working
on the compiler distribution, but also cross-compilation or porting to
new systems. During the 4.05 development period, Sébastien Hinderer
worked on harmonizing the build rules and merging the two build

  • Some changes were made to the config/Makefile file which
    is exported as $(ocamlc -where)/Makefile.config, and on
    which some advanced users might rely. The changes are
    as follows:

    • a BYTERUN variable was added that points to the installed ocamlrun
    • the PARTIALLD variable was removed (PACKLD is more complete)
    • the always-empty DLLCCCOMPOPTS was removed
    • the SHARED variable was removed; its value is “shared” or “noshared”,
      which duplicates the existing and more convenient
      SUPPORTS_SHARED_LIBRARIES variable whose value is “true” or “false”.

    Note that Makefile.config may change further in the future and relying
    on it is a bit fragile. We plan to make ocamlc -config easier to use
    for scripting purposes, and have a stable interface there. If you rely
    on Makefile.config, you may want to get in touch with Sébastien Hinderer
    or participate to PR#7116 (Allow easy retrieval of Makefile.config’s values)
    or PR#7172 (More information in ocamlc -config).

The complete list of changes is listed below.

  • GPR#705: update Makefile.nt so that ocamlnat compiles
    for non-Cygwin Windows ports.
    (Sébastien Hinderer, review by Alain Frisch)

  • GPR#729: Make sure ocamlnat is built with a $(EXE) extension, merge
    rules between Unix and Windows Makefiles
    (Sébastien Hinderer, review by Alain Frisch)

  • GPR#762: Merge build systems in the yacc/ directory.
    (Sébastien Hinderer, review by David Allsopp, Alain Frisch)

  • GPR#764: Merge build systems in the debugger/ directory.
    (Sébastien Hinderer, review by Alain Frisch)

  • GPR#785: Merge build systems in otherlibs/systhreads/
    (Sébastien Hinderer, review by Alain Frisch, David Allsopp,
    testing and regression fix by Jérémie Dimino)

  • GPR#788: Merge build systems in subdirectories of otherlibs/.
    (Sébastien Hinderer, review by Alain Frisch)

  • GPR#808, GPR#906: Merge Unix and Windows build systems
    in the ocamldoc/ directory
    (Sébastien Hinderer, review by Alain Frisch)

  • GPR#812: Merge build systems in the tools/ subdirectory
    (Sébastien Hinderer, review by Alain Frisch)

  • GPR#866: Merge build systems in the stdlib/ directory
    (Sébastien Hinderer, review by David Allsopp and Adrien Nader)

  • GPR#941: Merge Unix and Windows build systems in the asmrun/ directory
    (Sébastien Hinderer, review by Mark Shinwell, Adrien Nader,
    Xavier Leroy, David Allsopp, Damien Doligez)

  • GPR#981: Merge build systems in the byterun/ directory
    (Sébastien Hinderer, review by Adrien Nader)

  • GPR#1033, GPR#1048: Merge build systems in the root directory
    (Sébastien Hinderer, review by Adrien Nader and Damien Doligez,
    testing and regression fix by Andreas Hauptmann)

Internal/compiler-libs changes:

  • GPR#673: distinguish initialization of block fields from mutation in lambda.
    (Frédéric Bour, review by Xavier Leroy, Stephen Dolan and Mark Shinwell)

  • GPR#744, GPR#781: fix duplicate self-reference in imported cmi_crcs
    list in .cmti files + avoid rebuilding cmi_info record when creating
    .cmti files
    (Alain Frisch, report by Daniel Bünzli, review by Jérémie Dimino)

  • GPR#881: change Outcometree.out_variant to be more general.
    Ovar_name of out_ident * out_type list becomes Ovar_type of out_type.
    (Valentin Gatien-Baron, review by Leo White)

  • GPR#908: refactor PIC-handling in the s390x backend
    (Gabriel Scherer, review by Xavier Leroy and Mark Shinwell)

Bug fixes

  • PR#5115: protect all byterun/fail.c functions against
    uninitialized caml_global_data (only changes the bytecode behavior)
    (Gabriel Scherer, review by Xavier Leroy)

  • PR#6136, GPR#967: Fix Closure so that overapplication evaluation order
    matches the bytecode compiler and Flambda.
    (Mark Shinwell, report by Jeremy Yallop, review by Frédéric Bour)

  • PR#6550, GPR#1094: Allow creation of empty .cmxa files on macOS
    (Mark Shinwell)

  • PR#6594, GPR#955: Remove “Istore_symbol” specific operation on x86-64.
    This is more robust and in particular avoids assembly failures on Win64.
    (Mark Shinwell, review by Xavier Leroy, testing by David Allsopp and
    Olivier Andrieu)

  • PR#6903: Unix.execvpe doesn’t change environment on Cygwin
    (Xavier Leroy, report by Adrien Nader)

  • PR#6987: Strange error message probably caused by
    universal variable escape (with polymorphic variants)
    (Jacques Garrigue, report by Mikhail Mandrykin and Leo White)

  • PR#7216, GPR#949: don’t require double parens in Functor((val x))
    (Jacques Garrigue, review by Valentin Gatien-Baron)

  • PR#7331: ocamldoc, avoid infinite loop in presence of self alias,
    i.e. module rec M:sig end = M
    (Florian Angeletti, review Gabriel Scherer)

  • PR#7346, GPR#966: Fix evaluation order problem whereby expressions could
    be incorrectly re-ordered when compiling with Flambda. This also fixes one
    example of evaluation order in the native code compiler not matching the
    bytecode compiler (even when not using Flambda)
    (Mark Shinwell, Leo White, code review by Pierre Chambart)

  • PR#7348: Private row variables can escape their scope
    (Jacques Garrigue, report by Leo White)

  • PR#7407: Two not-quite-standard C idioms rejected by SUNWSPro compilers
    (Xavier Leroy)

  • PR#7421: Soundness bug with GADTs and lazy
    (Jacques Garrigue, report by Leo White)

  • PR#7424: Typechecker diverges on unboxed type declaration
    (Jacques Garrigue, report by Stephen Dolan)

  • PR#7426, GPR#965: Fix fatal error during object compilation (also
    introduces new [Pfield_computed] and [Psetfield_computed] primitives)
    (Mark Shinwell, report by Ulrich Singer)

  • PR#7427, GPR#959: Don’t delete let bodies in Cmmgen
    (Mark Shinwell, report by Valentin Gatien-Baron)

  • PR#7432: Linking modules compiled with -labels and -nolabels is not safe
    (Jacques Garrigue, report by Jeremy Yallop)

  • PR#7437: typing assert failure with nonrec priv
    (Jacques Garrigue, report by Anil Madhavapeddy)

  • PR#7438: warning +34 exposes #row with private types
    (Alain Frisch, report by Anil Madhavapeddy)

  • PR#7443, GPR#990: spurious unused open warning with local open in patterns
    (Florian Angeletti, report by Gabriel Scherer)

  • PR#7456, GPR#1092: fix slow compilation on source files containing a lot
    of similar debugging information location entries
    (Mark Shinwell)

  • PR#7504: fix warning 8 with unconstrained records
    (Florian Angeletti, report by John Whitington)

  • PR#7511, GPR#1133: Unboxed type with unboxed argument should not be accepted
    (Damien Doligez, review by Jeremy Yallop and Leo White)

  • GPR#795: remove 256-character limitation on Sys.executable_name
    (Xavier Leroy)

  • GPR#805, GPR#815, GPR#833: check for integer overflow in String.concat
    (Jeremy Yallop,
    review by Damien Doligez, Alain Frisch, Daniel Bünzli, Fabrice Le Fessant)

  • GPR#881: short-paths did not apply to some polymorphic variants
    (Valentin Gatien-Baron, review by Leo White)

  • GPR#886: Fix Ctype.moregeneral’s handling of row_name
    (Leo White, review by Jacques Garrigue)

  • GPR#934: check for integer overflow in Bytes.extend
    (Jeremy Yallop, review by Gabriel Scherer)

  • GPR#956: Keep possibly-effectful expressions when optimizing multiplication
    by zero.
    (Jeremy Yallop, review by Nicolás Ojeda Bär, Xavier Leroy and Mark Shinwell)

  • GPR#977: Catch Out_of_range in ocamldebug’s “list” command
    (Yunxing Dai)

  • GPR#983: Avoid removing effectful expressions in Closure, and
    eliminate more non-effectful ones
    (Alain Frisch, review by Mark Shinwell and Gabriel Scherer)

  • GPR#987: alloc_sockaddr: don’t assume a null terminator. It is not inserted
    on macOS by system calls that fill in a struct sockaddr (e.g. getsockname).
    (Anton Bachin)

  • GPR#998: Do not delete unused closures in un_anf.ml.
    (Leo White, review by Mark Shinwell and Pierre Chambart)

  • GPR#1019: Fix fatal error in Flambda mode “[functions] does not map set of
    closures ID”
    (Pierre Chambart, code review by Mark Shinwell and Leo White)

  • GPR#1075: Ensure that zero-sized float arrays have zero tags.
    (Mark Shinwell, Leo White, review by Xavier Leroy)

  • GPR#1088: Gc.minor_words now returns accurate numbers.
    (compatibility: the .mli declaration of Gc.minor_words
    and Gc.get_minor_free changed, which may break libraries
    re-exporting these values.)
    (Stephen Dolan, review by Pierre Chambart and Xavier Leroy)


How do you look for the GPR and MPR and the relevant merges?

GPRs are at URLs of the form https://github.com/ocaml/ocaml/pull/1234, while MPRs are at URLs of the form https://caml.inria.fr/mantis/view.php?id=1234.

I have a dumb script that add markdown links to the Changelog that I used to build the template for the annotated 4.04 changelog. I plan to do the same for 4.05, but didn’t have the time yet. I may edit the top post here with the links added for convenience.

1 Like

Neat trick for emacs – if you use something like:

(setq bug-reference-bug-regexp "\\(PR\\|GPR\\) ?#\\([0-9]+\\)")
(setq bug-reference-url-format 'ocaml-bug-reference-url)

(defun ocaml-bug-reference-url ()
  (let ((kind (match-string-no-properties 1))
        (number (match-string-no-properties 2)))
      ((equal kind "PR")
       (format "https://caml.inria.fr/mantis/view.php?id=%s" number))
      ((equal kind "GPR")
       (format "https://github.com/ocaml/ocaml/pull/%s" number))
      (t "BAD"))))

then you can view the OCaml Changes file with bug-reference-mode and each change will have a link to the corresponding issue.


Thanks, that made things much easier :slight_smile:

@gasche the post on annotated 4.04 was great. I am looking forward to read the annotated 4.05!

So I just created the 4.05.0 change explanation wikipage. Feel free to add you remarks there, I’ll eventually send it on the 4.05.0 release thread on the caml-list.


@gasche It looks like your links all point to ocaml/opam-repository GPRs rather than ocaml/ocaml.

Thank you for putting this together!

Thanks, fixed – and I edited the top post here with the links.

Over on reddit ocaml I was tricked into building a list of some changes I find interesting (not an exhaustive list, of course), which may interest people here:

For example, the afl-fuzz support from Stephen Dolan is quite nice and is instrumental in the excellent crowbar fuzzing library – see Mindy Preston’s blog post Crowbar Your Favorite Library for Fun and Bugfixes.

I also expect the new -args/-args0 support (to pass extra options to the compiler in a file, rather than on the command-line, to avoid OS-specific command line size limitations) contributed by Bernhard Schommer to simplify some people’s life. It exists now in the OCaml compiler, but the fact that it is in the Arg module in the standard library means that it should be easy for other OCaml programs to also take advantage of it if they wish to.

The -dtimings option tells more about where the compiler spends time (and, pretty soon, memory), which should make it easier to diagnose slow-build issues.

Thanks to Alain Frisch and many others, many stdlib functions have an _opt variant returning an option instead of raising an exception (List.find_opt). New stdlib functions take a bit of time to be adopted, though, as people understandbly want to remain compatible with recent-but-not-last OCaml versions.

François Bobot’s Printexc.raise_with_backtrace will make it much easier to catch, report and reraise exceptions in a way that does not break backtrace collection.

Florian Angeletti did a lot of small improvements to the manual and ocamldoc.

Sébastien Hinderer did a lot of internal work on the OCaml compiler build (the configure, Makefile, etc.), which makes it easier to maintain the compiler on Windows, and opens the door to an autoconf/automake approach in the future that could make feature detection more reliable and make porting to new systems easier.


Is there no release of 4.05+fp+flambda? I only see 4.05.0+flambda in opam so far.

There are not “releases” per se, just opam switches. Feel free to send a pull request to provide the switch with the combination of configure options of your choice.

Note that having frame-pointers should not be necessary for OCaml programs (but it might be useful for certain mixed-language applications that make tooling assumptions?). In particular, if you use them for profiling, perf on Linux supports using DWARF debug information itself to reconstruct backtraces, so perf record --call-graph=dwarf should work – this is documented in the Performance and profiling page.

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@gasche Interesting. Thanks for the link and the explanation. :slight_smile:

Are you planning to submit a +fp+flambda switch? Do you need help/guidance for how to do it?

Basically: clone the opam repository, go to compilers/, look at how it is done and adapt it to what you need.

If you want to test before you send the PR:

opam repo add my-local-repo <path-to-your-repo>
opam update my-local-repo
opam switch install <the-switch-you-added>
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Hi @gasche,

I would love to, however, I am bit pre-occupied with a few other things at the moment. So I am not planning on submitting a pull request in the immediate time frame. Possibly after the next few weeks I will come back to this. I will ping you then.

Many Thanks