Changes

extend Lambda.subst on bound variables, add Lambda.duplicate

It is invalid to reuse a Lambda.t term twice, because bound variables
may be used non-uniquely. If we want to perform a code transformation
may duplicate subterms in some cases, we have to refresh all bound
variables of the copied subterm.

The present PR implements a function

    Lambda.duplicate : lambda -> lambda

that does exactly this. It is implemented by making Lambda.subst
parametrized over a transformation on bound variables.
 (commit: cc7d557)

Report full major collections in Gc stats
 (commit: dfd0c0c)

Add Changes entry
 (commit: 0734368)

Avoid warning 58 in flambda ocamlnat
 (commit: 9e61a06)

Add Changes entry
 (commit: 5e21404)

Treat loops properly in un_anf (#9163)

 (commit: 368eb16)

Fix PR#7897
 (commit: b436128)

Add Changes entry
 (commit: 083fa66)

Fix Changes after backporting #9163 and #9537
 (commit: b212928)

correct punctuation
 (commit: b6af921)

Fix #8747: incorrect principality warning on functional updates of records (#9709)

 (commit: e0ec63a)

Changes bookkeeping: 9556 is not in 4.11
 (commit: 33b9b16)

Bump FlexDLL submodule to 0.38
 (commit: bfd3d7d)

Use the alignas C++ keyword when compiling in C++

See #9714.
 (commit: 4d6d422)

Add a terminator to the domain_state

On a 32-bits architecture, if the last member of the caml_domain_state
is a pointer, it will be 4-bytes long, and the struct will end after a
4 bytes boundary, failing the assertion.

As @xavierleroy [put it][1]:

> we don't care about the total size of the struct, but we care that
> the members before `end_of_domain_state` are spaced by 8.

[1]: https://github.com/ocaml/ocaml/issues/9714#issuecomment-650516382

See #9714.
 (commit: cba42a3)

misplaced subsection '*'

and hence the rendered subsection title only contained "*"
 (commit: df87f39)

Move calls to exit to main/optmain
 (commit: d5af1ff)

Move code of main and optmain to compilerlibs
 (commit: 81618f7)

Start Clflags.parse_arguments from 0
 (commit: c2461c0)

Changes
 (commit: 34ead63)

Consistently use @raise tags in Stdlib docs (#8644)

 (commit: c4851b0)

Add module utils/binutils
 (commit: 34ff264)

Adapt ocamlobjinfo
 (commit: a8f05ad)

Adapt test
 (commit: 32cc562)

Adapt ocamlc primitive check
 (commit: 3fb5dbb)

make alldepend
 (commit: 6ab3220)

Remove integration with libbfd
 (commit: 0b6ebb3)

autogen
 (commit: f1b42fa)

Changes
 (commit: cb3af25)

Update version format
 (commit: cd813bc)

Get rid of dead code that was introduced for an hypothetical JIT (#9710)

That code was never used and some of it is outdated.
 (commit: 0616261)

Fix #9721: Injectivity and recursive modules (#9727)

 (commit: 46cec11)

Remove caml_lazy_follow_forward (unused since 666cb14a)

A bootstrap is needed after this commit.
 (commit: dcb7fb1)

Bootstrap.
 (commit: 788f744)

Add missing space
 (commit: 761dec8)

add manual page for the instrumented runtime
 (commit: f3ee9e3)

instrumented runtime: change environment variable from OCAML_EVENTLOG_FILE to OCAML_EVENTLOG_PREFIX
 (commit: f674c27)

update Changes entry for the instrumented runtime manual page
 (commit: cfb62e3)

manual: adjustments to the instrumented runtime manual page
 (commit: 9ba979e)

type_cases: rely on levels to enforce principality (#1931)

Instead of the erasure scheme that was used up to now, where we
considered that the type was always principal.

Note: the erasure still happens when polymorphic variants appear in the
patterns, and the type of the scrutinee contains a Reither.
 (commit: 167e66e)

manual: fix typo in instrumented runtime manual
 (commit: a8b782b)

manual: fix a typo in instrumented runtime manpage
 (commit: 4765f24)

Changes: instrumented runtime doc is in 4.11
 (commit: 3d45b6c)

pass a proper location to Matching.for_trywith

Actually *using* the location in the failure handler would be
incorrect, as it adds noise to backtraces involving partial exception
handlers. This is now properly documented.

We still take the caller location (which is currently ignored) for
consistency with other toplevel Matching functions, and because that
may become useful if we want to add more error-reporting or warnings
in compile_matching.
 (commit: 6aeed1c)

matching: a first-order representation for match-failure handling
 (commit: fdf86ad)

pattern aliases do not ignore type constraints (#1655)

 (commit: 4edc4b9)

update News
 (commit: 6236bac)

fix long line in News
 (commit: 10cb814)

Simplified compaction without page table (#9728)

Taking advantage of the new closure representation, this PR simplifies the compaction algorithm (3 passes instead of 4) and remove the use of the page table in no-naked-pointers mode.
 (commit: 601819f)

Extend Printexc API for raw backtrace entries (#9663)

 (commit: 523fba9)

Update config.guess and config.sub

To version 2020-07-12 from git://git.savannah.gnu.org/config.git
This adds support for iOS/macOS AArch64.
 (commit: 8bd19b7)

Add Changes entry for PR #9551
 (commit: 8948dab)

Fix "main" CI script w.r.t. macOS

Stopped working after 0b6ebb315
 (commit: 2b24b38)

Test no-naked-pointers on GitHub Actions
 (commit: a8b647f)

Spurious comma in the endianness test, big-endian case
 (commit: efc1185)

The best-fit allocator must prepare the heap for compaction. Fixes #9736
 (commit: 85e4563)

fix and move Changes entry for #9749
 (commit: e509c79)

Mark new macros Val_none, etc as as a potentially breaking change (#9734)

If an OCaml C library already defines some of the new `Val_none`,
`Some_val`, `Is_none`, `Is_some`, `caml_alloc_some`, or `Tag_some`
macros; then the C compiler will likely warn for macro redefinition,
even if the macro definition are identical.
 (commit: fb6cfaf)

Fix UB when left-shifting a negative value
 (commit: 3aa92b1)

Fix memory leak

Some [Linux manpages][1] state

> This function makes copies of the strings pointed to by name and
> value (by contrast with putenv(3)).

and the [OpenGroup][2] manpage also states that the strings are
copied, so indeed they can and should be freed afterwards.

[1]: https://man7.org/linux/man-pages/man3/setenv.3.html
[2]: https://pubs.opengroup.org/onlinepubs/009695399/functions/setenv.html
 (commit: c944d64)

Fix invalid format specifiers
 (commit: d2d2e0c)

Represent eventlog_startup_pid as long int
 (commit: 873b314)

Remove some unused primitives

caml_input_value_from_string (unused since e227fb007d)
caml_ml_flush_partial, caml_ml_output_partial (unused since 705054b3)
caml_obj_is_block (unused since b1f93a66)
 (commit: 131099a)

Bootstrap
 (commit: 1c9e1e0)

Add some injectivity annotations to the standard library.
 (commit: 0aa72dd)

Stdlib injectivity: update tests.
 (commit: fb2f26a)

Update a comment in the top-level printer. (#9777)

The following code is no longer valid, even with -rectypes:

   let rec x = lazy x

But the toplevel printer still needs to detect cycles involving Forward
tags, which can be created (without -rectypes) using unboxing:

    type t = T : t Lazy.t -> t [@@unboxed]
    let rec x = lazy (T x)
 (commit: 0ad9f06)

Documentation: Improve the list of build-time requirements (#9733)

The list of prerequisites in INSTALL.adoc was not quite complete.
This PR adds the missing requirements and removes some requirements that are no longer relevant.
 (commit: b0118a9)

Add Hashtbl.rebuild function

This provides an officially-sanctioned, guaranteed-to-work way to
import a hash table that has been built with an old version of OCaml
(say, before 4.00) and marshaled to persistent storage.
 (commit: a6f03cc)

Hashtbl: remove support for pre-4.00 hash tables

When the hash function and the internal representation of hash tables
was changed in 4.00, some compatibility code was left so that "old"
hash tables (created with OCaml < 4.00 and marshaled to files)
could still be operated upon by the functions of the new implementation.

This was 9 years ago, so it is reasonable to expect that none of these
"old" hash tables are still in use.

This commit removes the compatibility code in stdlib/hashtbl.ml.
It still tries to detect "old" hash tables and raise an
Invalid_argument exception instead of crashing.
 (commit: 40399cc)

hash.c: remove the caml_hash_univ_param function

This function implements the old, pre-4.00 hashing scheme that is
no longer used (as a compatibility backup) in stdlib/hashtbl.ml.
It is therefore dead code.
 (commit: e728e92)

Bootstrap after removal of `caml_hash_univ_param` primitive
 (commit: de4377e)

Add a test for Hashtbl.rebuild
 (commit: cfabfe6)

Changes entry for #9763
 (commit: 569085b)

Fix printing of bindings with polymorphic type annotations and attributes (#9778)

 (commit: dd7ddf9)

Stdlib injectivity annotations: Changes.
 (commit: 568a0f5)

Introduce mnemnonics for warnings
 (commit: 1647c47)

Rename Statement_type => Non_unit_statement
 (commit: fd48548)

Rename Unused_match => Unused_case
 (commit: 45d1446)

Rename Unused_pat => Unused_subpat
 (commit: b2606e0)

Rename Without_principality => Non_principal_labels
 (commit: e05f119)

Rename Unused_argument => Unreachable_argument
 (commit: 358a6c1)

Rename Multiple_definition => Module_linked_twice
 (commit: 9f9cc29)

Rename Bad_docstring => Unexpected_docstring
 (commit: a0cef9f)

Rename Expect_tailcall => Tailcall_expected
 (commit: 5789d6c)

Rename Ambiguous_pattern => Ambiguous_var_in_pattern_guard
 (commit: 14f8fa5)

Rename Assignment_to_non_mutable_value => Flambda_assignment_to_non_mutable_value
 (commit: 85a7e8e)

Rename Unsafe_without_parsing => No_unsafe_array_syntax_without_parsing
 (commit: f9786a9)

Rename Partial_application => Ignored_partial_application
 (commit: f3c6b16)

Rename Non_closed_record_pattern => Missing_record_field_pattern
 (commit: ca4b8dc)

Rename Unused_case => Redundant_case
 (commit: 47c0e44)

Rename Unused_subpat => Redundant_subpat
 (commit: 06f1a66)

Rename Unreachable_argument => Ignored_argument
 (commit: 958281d)

Rename No_unsafe_array_syntax_without_parsing => Unsafe_array_syntax_without_parsing
 (commit: 9ac31c2)

Typo
 (commit: dae2280)

Display warning names in manual
 (commit: a68791f)

Update manual
 (commit: 2ade04e)

Changes
 (commit: af8ecad)

Add constructor-mnemonic check to testsuite
 (commit: 39f6374)

Fix mnemonics, handle warnings without names
 (commit: 5e09060)

Warning 25: make it clear that it is ignored
 (commit: a73fedb)

check-typo
 (commit: 5e27454)

Rename Ignored_argument => Ignored_extra_argument
 (commit: fb76c32)

Test "no naked pointers" along with "flambda"
 (commit: de87785)

Selectgen#bind_let_mut: use self#regs_for to allocate target registers (#9782)

Software emulation of floating-point arithmetic, as in the ARM EABI port,
use pairs of pseudoregisters of type Int to represent values of type Float.

This is achieved by the `regs_for` method of class `selector_generic`,
which defaults to `Reg.createv` but is overriden for ARM EABI so
as to perform the transformation Float -> Int,Int on the fly.

The method `bind_let_mut` uses `Reg.createv` to associate
pseudoregisters to bound variables.  This is incorrect in a soft FP
context, as a bound variable of type Float will get a Float register
nonetheless.  `self#regs_for` must be used instead.  This is what this
commit does.
 (commit: 1e71f75)

Include mnemonic when displaying warnings
 (commit: 68be98d)

Adapt caml-tex
 (commit: 214146c)

Fix typo
 (commit: c3bbb50)

Update test reference files
 (commit: 3407c3b)

Avoid breaking string literal
 (commit: 7e5a60b)

Update expected test output

Follow-up to PR #9657
 (commit: 9f25b62)