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garrigue and others added 30 commits May 25, 2020 19:04
On by default if +dev appears in VERSION and also fixed for MSVC.
More partial application warnings
This PR fixes an old bug in the interaction between [merge_constraint]
and [Typedecl.transl_with_constraint], where
variance (and now separability) are recomputed in an invalid type
environment. See ocaml#9624 and the new tests.
(suggested by Leo White and Jacques Garrigue)
fix an environment problem in merge_constraint
Also: better explain how to encapsulate naked pointers in Abstract blocks.
Following review comments.

Also: fix the assertion in the third val_of_typtr function.
Allow ',' at the start of OCAMLRUNPARAM
xavierleroy and others added 23 commits June 8, 2020 14:13
…ebugger

This avoids the quadratic behaviors of the previous array-based
implementation.

Closes: ocaml#9606
Introduce a library of skip lists and use them to fix a performance issue in the debugger (issue ocaml#9606)
We want to start allowing more information in the payload of
[@tailcall] attributes (currently no payload is supported), for
example we could consider using [@tailcall false] to ask the code
generator to disable a tail call.

A first required step in this direction is to use a custom datatype to
represent the tail-call attribute, instead of a boolean. This is
consistent with the other application-site
attributes (inline_attribute, specialise_attribute, local_attribute),
so it makes the code more regular -- but the change itself is
boilerplate-y.
Eliminate MKEXE_ANSI from build system
matching: refactor the local control flow of the Unused exception
[minor] refactoring the datatype for the [@tailcall] attribute
…port

ocamldoc: remove debugging facility
--enable-warn-error configure option
* Memprof: disable sampling when memprof is suspended.

* Changes.
This patch removes casts between struct skiplist * and struct skipcell *, and removes the "layout compatibility" fields in skiplist that were there to enable these casts.

The only algorithmic difference is that caml_skiplist_find is now "stop-at" (see discussion here), as this was slightly easier to write in the no-cast style.
* Remove temporary hack related to the Num library

This is a follow-up to commit 3de0115

* Also do some cleanup in stdlib/Makefiile
* Introducing codefrag: a new runtime module to work with code fragments

This module collects all the operations on code fragments performed in
various places of the runtime systems.  Applies both to bytecode and
to native code.

The implementation is based on skiplists, so that "lookup fragment by
PC" and "lookup fragment by number" are efficient (logarithmic in the
number of code fragments).  "Lookup fragment by digest" remains
linear-time.

The new module also improves the handling of digests: now it is
possible to mark a code fragment as "no digest" i.e. not marshal-able.

* Use the new "codefrag" runtime module for marshaling and for the
  debugger interface

Replace the previous handling of code fragments with calls to the
functions provided by the "codefrag" runtime module.
@lthls
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lthls commented Jun 23, 2020

That looks great. I suggest you try to see if you can also remove the exit_label reference.

@Anukriti12 Anukriti12 closed this Aug 11, 2020
lthls pushed a commit that referenced this pull request Aug 13, 2024
…l#13294)

The toplevel printer detects cycles by keeping a hashtable of values
that it has already traversed.

However, some OCaml runtime types (at least bigarrays) may be
partially uninitialized, and hashing them at arbitrary program points
may read uninitialized memory. In particular, the OCaml testsuite
fails when running with a memory-sanitizer enabled, as bigarray
printing results in reads to uninitialized memory:

```
==133712==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x4e6d11 in caml_ba_hash /var/home/edwin/git/ocaml/runtime/bigarray.c:486:45
    #1 0x52474a in caml_hash /var/home/edwin/git/ocaml/runtime/hash.c:251:35
    #2 0x599ebf in caml_interprete /var/home/edwin/git/ocaml/runtime/interp.c:1065:14
    #3 0x5a909a in caml_main /var/home/edwin/git/ocaml/runtime/startup_byt.c:575:9
    #4 0x540ccb in main /var/home/edwin/git/ocaml/runtime/main.c:37:3
    #5 0x7f0910abb087 in __libc_start_call_main (/lib64/libc.so.6+0x2a087) (BuildId: 8f53abaad945a669f2bdcd25f471d80e077568ef)
    #6 0x7f0910abb14a in __libc_start_main@GLIBC_2.2.5 (/lib64/libc.so.6+0x2a14a) (BuildId: 8f53abaad945a669f2bdcd25f471d80e077568ef)
    #7 0x441804 in _start (/var/home/edwin/git/ocaml/runtime/ocamlrun+0x441804) (BuildId: 7a60eef57e1c2baf770bc38d10d6c227e60ead37)

  Uninitialized value was created by a heap allocation
    #0 0x47d306 in malloc (/var/home/edwin/git/ocaml/runtime/ocamlrun+0x47d306) (BuildId: 7a60eef57e1c2baf770bc38d10d6c227e60ead37)
    #1 0x4e7960 in caml_ba_alloc /var/home/edwin/git/ocaml/runtime/bigarray.c:246:12
    #2 0x4e801f in caml_ba_create /var/home/edwin/git/ocaml/runtime/bigarray.c:673:10
    #3 0x59b8fc in caml_interprete /var/home/edwin/git/ocaml/runtime/interp.c:1058:14
    #4 0x5a909a in caml_main /var/home/edwin/git/ocaml/runtime/startup_byt.c:575:9
    #5 0x540ccb in main /var/home/edwin/git/ocaml/runtime/main.c:37:3
    #6 0x7f0910abb087 in __libc_start_call_main (/lib64/libc.so.6+0x2a087) (BuildId: 8f53abaad945a669f2bdcd25f471d80e077568ef)
    #7 0x7f0910abb14a in __libc_start_main@GLIBC_2.2.5 (/lib64/libc.so.6+0x2a14a) (BuildId: 8f53abaad945a669f2bdcd25f471d80e077568ef)
    #8 0x441804 in _start (/var/home/edwin/git/ocaml/runtime/ocamlrun+0x441804) (BuildId: 7a60eef57e1c2baf770bc38d10d6c227e60ead37)

SUMMARY: MemorySanitizer: use-of-uninitialized-value /var/home/edwin/git/ocaml/runtime/bigarray.c:486:45 in caml_ba_hash
```

The only use of hashing in genprintval is to avoid cycles, that is, it
is only useful for OCaml values that contain other OCaml values
(including possibly themselves). Bigarrays cannot introduce cycles,
and they are always printed as "<abstr>" anyway.

The present commit proposes to be more conservative in which values
are hashed by the cycle detector to avoid this issue: we skip hashing
any value with tag above No_scan_tag -- which may not contain any
OCaml values.

Suggested-by: Gabriel Scherer <[email protected]>

Signed-off-by: Edwin Török <[email protected]>
Co-authored-by: Edwin Török <[email protected]>
lthls pushed a commit that referenced this pull request Sep 23, 2025
Move the orphaned ephemerons GC colour check inside the barrier.
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