Branch: stable (switch to development),

version to version

SWI-Prolog Changelog from version 8.4.0 to 8.4.1

[Nov 16 2021]

FIXED: Saved state handling of a dict whose first key value (in the internal order) and tag are both avoid variables. This patch is less invasive than 4de9114a76cd44659591296627e999cf1072d744.

[Nov 15 2021]

FIXED: Saved state handling of a dict whose first key value (in the internal order) and tag are both avoid variables. Reported by Matt Lilley.

[Nov 12 2021]

FIXED: Be more relaxed about existence of the current predicate when pushing and popping the compilation context.

[Nov 11 2021]

ENHANCED: Get version info into the Prolog flag. Now uses CMake rather than a shell script and provides a new Prolog flag cmake_build_type.

[Nov 10 2021]

DOC: meta_predicate/1: updated mode declarations.

[Nov 8 2021]

EHNACED: pack_rebuild/1,2 for CMake based packages to use `cmake --build and cmake --install` for the build and install steps rather than calling make, ninja, etc. directly. Suggested by Wouter Beek.
MAINTENANCE: Possible segv in retract/1 when compiled using O_DEBUG.

[Nov 7 2021]

FIXED: Possible race conditions between the various ways a thread can be joined.
FIXED: Do not start a new thread to join garbage collected threads while shutting down the system.
MAINTENANCE: On a system error we only go into interactive mode if both stdin and stderr are connected to a terminal. Otherwise we print the message, C and Prolog stack and abort.
MAINTENANCE: Use of guarded C-stack using sigaltstack() doesn't go with ASAN. Results in the error below. Disabled guarding the C stack when compiling using address sanitizer. ``` =101190=ERROR: AddressSanitizer failed to deallocate 0x2000 (8192) bytes at address 0x6250000b1900 =101190=AddressSanitizer CHECK failed: ../../../../src/libsanitizer/sanitizer_common/sanitizer_posix.cc:60 "(("unable to unmap" && 0)) != (0)" (0x0, 0x0)
```

[Nov 3 2021]

FIXED: CMake packs must use environment variables.
ADDED: Support ninja builds when using CMake
FIXED: pack_install/1,2: If we use CMake for configuration, we should also build in the CMake directory.
TEST: Signalled thread may already be dead.

[Nov 2 2021]

ADDED: pack_install/1,2: provide pack_install(.) to add the local directory to the pack registry and build it. Also add option link(true) and rebuild(When) to provide more fine control over the build.
FIXED: pack_install/1,2: do not remove contents if the package registered as a symbolic link.
FIXED: memberchk/2 for partial lists where the unbound part is constrained. Reported on Discourse by Abramo Bagnara.
BUILD: Avoid GCC-11 warning

[Oct 31 2021]

ENHANCED: Protect assertz/1 and friends (compiler) against C-stack overflows.
ENHANCED: Use setjmp() instead of sigsetjmp() to reduce the overhead of the C-stack guarding.
MAINTENANCE: Updated C calltree analysis for CMake build and new coding style and conventions.

[Oct 30 2021]

FIXED: Fallback to find a place for packages to install executables.
FIXED: Hash consistency on pointer sided integers for 64-bit bigendian machines. Only affects consistency of term_hash/2 over platforms.
FIXED: Checking that an uncaught exception is caught in an outer environment, i.e., nested C<->Prolog callback.

[Oct 28 2021]

FIXED: Make C-stack guarding work in threads.
ENHANCED: Use C-stack guarding for read/1 and friends.
FIXED: format/2,3: Term printing using ~[kpqw] did not propagate exception.

[Oct 27 2021]

ENHANCED: Handle C-stack overflows gracefully on POSIX targets with sigaltstack().

[Oct 26 2021]

ADDED: argv_options/3: allow including longer descriptions as header, usage and footer in the usage message.
ADDED: argv_options/3: Allow the user to redefine the bindings for help. Suggested by @swi.
PORT: Alignment on ppc64el. Better version than df1f0bf795a16edd313a2a25f0678ce044a4a71d
PORT: Alignment on ppc64el (Debian). See https://github.com/SWI-Prolog/issues/issues/104

[Oct 25 2021]

FIXED: pl_get_uint64() for GMP numbers on 32-bit systems.
ADDED: argv_options/3,4: allow for disjunctive types.

[Oct 24 2021]

ADDED: library(prolog_versions) to simplify demanding minimal version and features of the hosting Prolog system.
ADDED: argv_options/4: options_after_arguments(false) option to stop processing options after the first positional argument.
ADDED: win_get_user_preferred_ui_languages/2 to get access to the user's preferred UI languages on Windows.
INSTALL: Windows: avoid confusing uninstall version message.

[Oct 22 2021]

ENHANCED: Allow loading library(prolog_debug) if spy and/or nospy are defined as operators.
FIXED: Do not reclaim memory on termination when we failed to terminate all threads.
ENHANCED: Provide a non-polling process termination procedure for systems that do not have sem_timedwait() such as MacOS.
ENHANCED: Improve performance for process shutdown on POSIX systems that support sem_timedwait() by avoiding a polling loop. This typically saves 0.1 second on the elapsed time for short lived executables.

[Oct 21 2021]

ADDED: Allow --no-pce together with -c (compile) to produce a state that does not include xpce.
FIXED: Retract for retract((a:-true)). Reported by Fernando Sáenz-Pérez.

[Oct 20 2021]

ADDED: argv_options/3: type term

[Oct 19 2021]

ADDED: argv_options/3 to provide a full featured and lightweight alternative to library(optparse).
FIXED: format/2 and friends: verify error when emitting rubber.
ADDED: format/2 and friends: support ~:|, the colon modifier for tab stops to insert a newline if the current column already passed the tab stop.
FIXED: Issue#896: Claim that memory streams as used by e.g. open_string/2 are reported as repositionable. Reported by Matthijs van Otterdijk.
ENHANCED: Allow 64-bit seek function to work on memory streams.
ADDED: Allow stream contol functions to return whether the stream is repositionable.

[Oct 18 2021]

FIXED: det/1: avoid false non-determinism claim if all relevant choicepoints are debug choicepoints.

[Oct 14 2021]

FIXED: Predicate access in nested transactions for clauses that are removed in the parent (or a previous nested) transaction. We must inspect the affected clauses of all parent transactions. Reported by Eric Zinda.

[Oct 11 2021]

FIXED: Answer subsumption tabling case provided by Annie Liu.
ADDED: Predicate property sig_atomic. Currently only for the built-in sig_atomic/1.

[Oct 9 2021]

FIXED: Delay signals in prolog_exception_hook/4.

[Oct 10 2021]

ADDED: sig_atomic/1 to run goals protected from signals. This predicate used to be available as the undocumented '$sig_atomic'/1. '$sig_atomic'/1 is now available from library(backcomp).
ENHANCED: thread_signal/2: reduce the locked section

[Oct 11 2021]

FIXED: thread_wait/2: return when condition is true before this predicate is called.
FIXED: thread_wait/2: wait_preds option accepted non-predicate indicators.
ADDED: sandbox: call_delays/2 as safe meta predicate

[Oct 6 2021]

FIXED: Issue#889: swipl --abi-version crashed.

[Oct 5 2021]

ENHANCED: trace/2 to delete that we are tracing this predicate if the port list is empty.

[Oct 1 2021]

DOC: Document key pc of prolog_choice_attribute/3
FIXED: 91d73fb8a859c6e0f0d97ff553f96903816bc18c triggers another case where the falsecount of a node can underflow during re-evaluation. Bit dubious.
DOC: LaTeX formatting error

Package cpp

[Oct 27 2021]

CLEANUP: SWI-cpp.h: more consistent type handling and silence several more casts.
COMPATIBILITY: SWI-cpp.h to use static_cast<type>(expression) to avoid warnings on modern C++ compilers.

Package http

[Oct 25 2021]

ADDED: JSON writer for dicts now have a hook json_dict_pairs/2 that allows the user to select keys from the dict and particularly define the order of keys in the resulting JSON.

[Oct 12 2021]

ADDED: http_read_data/4: handle the input_encoding/1 option when using to(Type).

[Oct 7 2021]

FIXED: range streams: be careful about race conditions when asynchronously finding all streams that refer to OS file handles.

Package jpl

[Nov 2 2021]

BUILD: Silence GCC-11 warning (ugly)

Package mqi

[Nov 11 2021]

UPDATE: Missing file from last commit
FIXED: File Handle Leak reported by @andrzej-at-mazurkiewicz-org Original bug report is: https://github.com/SWI-Prolog/packages-mqi/issues/13
Need to call: self._process.exit(None, None, None)

instead of:

result = self._process.wait()

as it will close the stderr/out handles too. Otherwise they will leak since they are used and thus opened (but not closed) by the Popen object.

[Nov 1 2021]

TEST: Handle all failures from test_server_options_and_shutdown as warnings unless "SWIPL_TEST_FAIL_ON_UNLIKELY=y" This test has lots of threading and potential race conditions so it can fail when the system is heavily loaded.
Handle by catching all exceptions and only actually failing if SWIPL_TEST_FAIL_ON_UNLIKELY - y

[Oct 22 2021]

DOC: Update URLs from EricZinda/swiplserver to packages-mqi
ADDED: All files needed to actually build the Python 'swiplserver' model and post to pypi.org so that 'pip install swiplserver' works Includes instructions on how to the build the model in /BuildingAndTesting.md

[Oct 20 2021]

ENHANCED: Use new controlled options and automatic help.
ENHANCED: Include dependencies to make mqi run with disabled autoloading.
FIXED: Use argv rather than os_argv. Breaks on new argv_options/3.

Package odbc

[Nov 10 2021]

CMAKE: Requires minimally cmake 3.9

[Oct 13 2021]

TEST: Include ODBC tests based on the environment variable SWIPL_TEST_ODBC_DRIVER. Also fixes cleanup of the ODBC tests.
FIXED: Ensure statement is closed in two scenarios.

[Oct 5 2021]

FIXED: Properly translate non-ASCII ODBC messages to Unicode.
FIXED: Cleanup the remains of old work-arounds or broken MS SQLServer SQLColumns() and add a new one. odbc_table_column/3 stops with the error Invalid Descriptor Index trying to fetch the column name using SQLGetData(). The work-around sets the column with for this query to 8K, avoiding SQLGetData(). Thanks to Fernando Sáenz-Pérez for reporting and providing access to a server.

Package pengines

[Oct 11 2021]

ENHANCED: Provide CSS style wfs_undefined for undefined answers.

[Oct 7 2021]

ADDED: portray//2 hook that plays a role similar to portray/1 for HTML rendering of terms.

Package protobufs

[Oct 31 2021]

FIXED: Issue #15 (long directory name) Shorten directory protoc_gen_prolog_pb to gen_pb for R build (R build outputs a warning if a the path is more than 100 bytes)

[Oct 25 2021]

FIXED: uint32_codes/2 in mode (-,+) on may return a negative value on 32-bit systems.

Package redis

[Nov 8 2021]

TEST: Prevent occasional early termination in test(primes).
TEST: Make sure the Redis test group consumers are properly discarded.

Package semweb

[Nov 2 2021]

BUILD: Trick GCC-11 we are not really freeing a non-heap address.

Package sgml

[Oct 7 2021]

FIXED: xml_quote_cdata/3: possible race condition if two threads use this for the first time.

Package ssl

[Nov 2 2021]

BUILD: Silence (incorrect) GCC-11 uninitialized warning.

Package xpce

[Nov 7 2021]

PORT: remove Cygwin from targets requiring dllexport Cygwin ld uses auto-export by default. Mixing that with dllexport in some cases leaves other symbols unexported.
Signed-off-by: Corinna Vinschen <vinschen@redhat.com>

[Nov 2 2021]

BUILD: Avoid GCC-11 warning.

[Oct 21 2021]

FIXED: Do not setup search path for library(pce) if --no-pce is given.