remove JIT compiler from Octave sources As stated in the NEWS file entry added with this changeset, no one has ever seriously taken on further development of the JIT compiler in Octave since it was first added as part of a Google Summer of Code project in 2012 and it still does nothing significant. It is out of date with the default interpreter that walks the parse tree. Even though we have fixed the configure script to disable it by default, people still ask questions about how to build it, but it doesn’t seem that they are doing that to work on it but because they think it will make Octave code run faster (it never did, except for some extremely simple bits of code as examples for demonstration purposes only). * NEWS: Note change. * configure.ac, acinclude.m4: Eliminate checks and macros related to the JIT compiler and LLVM. * basics.txi, install.txi, octave.texi, vectorize.txi: Remove mention of JIT compiler and LLVM. * jit-ir.cc, jit-ir.h, jit-typeinfo.cc, jit-typeinfo.h, jit-util.cc, jit-util.h, pt-jit.cc, pt-jit.h: Delete. * libinterp/parse-tree/module.mk: Update. * Array-jit.cc: Delete. * libinterp/template-inst/module.mk: Update. * test/jit.tst: Delete. * test/module.mk: Update. * interpreter.cc (interpreter::interpreter): Don't check options for debug_jit or jit_compiler. * toplev.cc (F__octave_config_info__): Remove JIT compiler and LLVM info from struct. * ov-base.h (octave_base_value::grab, octave_base_value::release): Delete. * ov-builtin.h, ov-builtin.cc (octave_builtin::to_jit, octave_builtin::stash_jit): Delete. (octave_builtin::m_jtype): Delete data member and all uses. * ov-usr-fcn.h, ov-usr-fcn.cc (octave_user_function::m_jit_info): Delete data member and all uses. (octave_user_function::get_info, octave_user_function::stash_info): Delete. * options.h (DEBUG_JIT_OPTION, JIT_COMPILER_OPTION): Delete macro definitions and all uses. * octave.h, octave.cc (cmdline_options::cmdline_options): Don't handle DEBUG_JIT_OPTION, JIT_COMPILER_OPTION): Delete. (cmdline_options::debug_jit, cmdline_options::jit_compiler): Delete functions and all uses. (cmdline_options::m_debug_jit, cmdline_options::m_jit_compiler): Delete data members and all uses. (octave_getopt_options long_opts): Remove "debug-jit" and "jit-compiler" from the list. * pt-eval.cc (tree_evaluator::visit_simple_for_command, tree_evaluator::visit_complex_for_command, tree_evaluator::visit_while_command, tree_evaluator::execute_user_function): Eliminate JIT compiler code. * pt-loop.h, pt-loop.cc (tree_while_command::get_info, tree_while_command::stash_info, tree_simple_for_command::get_info, tree_simple_for_command::stash_info): Delete functions and all uses. (tree_while_command::m_compiled, tree_simple_for_command::m_compiled): Delete member variable and all uses. * usage.h (usage_string, octave_print_verbose_usage_and_exit): Remove [--debug-jit] and [--jit-compiler] from the message. * Array.h (Array<T>::Array): Remove constructor that was only intended to be used by the JIT compiler. (Array<T>::jit_ref_count, Array<T>::jit_slice_data, Array<T>::jit_dimensions, Array<T>::jit_array_rep): Delete. * Marray.h (MArray<T>::MArray): Remove constructor that was only intended to be used by the JIT compiler. * NDArray.h (NDArray::NDarray): Remove constructor that was only intended to be used by the JIT compiler. * dim-vector.h (dim_vector::to_jit): Delete. (dim_vector::dim_vector): Remove constructor that was only intended to be used by the JIT compiler. * codeql-analysis.yaml, make.yaml: Don't require llvm-dev. * subst-config-vals.in.sh, subst-cross-config-vals.in.sh: Don't substitute OCTAVE_CONF_LLVM_CPPFLAGS, OCTAVE_CONF_LLVM_LDFLAGS, or OCTAVE_CONF_LLVM_LIBS. * Doxyfile.in: Don't define HAVE_LLVM. * aspell-octave.en.pws: Eliminate jit, JIT, and LLVM from the list of spelling exceptions. * build-env.h, build-env.in.cc (LLVM_CPPFLAGS, LLVM_LDFLAGS, LLVM_LIBS): Delete variables and all uses. * libinterp/corefcn/module.mk (%canon_reldir%_libcorefcn_la_CPPFLAGS): Remove $(LLVM_CPPFLAGS) from the list. * libinterp/parse-tree/module.mk (%canon_reldir%_libparse_tree_la_CPPFLAGS): Remove $(LLVM_CPPFLAGS) from the list.

--- a/NEWS	Mon Aug 09 16:30:48 2021 +0200
+++ b/NEWS	Tue Aug 10 16:42:29 2021 -0400
@@ -293,7 +293,7 @@
   work.
 
 
-### Removed functions and properties
+### Removed functions, properties, and features
 
 The following functions and properties were deprecated in Octave 5
 and have been removed from Octave 7.
@@ -315,6 +315,19 @@
   `uipanel`        | `fontangle`   | `"oblique"`
   `uitable`        | `fontangle`   | `"oblique"`
 
+- The prototype JIT compiler has been removed from Octave.  Since it was
+first added as part of a Google Summer of Code project in 2012, no one
+has ever seriously taken on further development of it and it still does
+nothing significant.  It is out of date with the default interpreter
+that walks the parse tree.  Even though we have fixed the configure
+script to disable it by default, people still ask questions about how to
+build it, but it doesn’t seem that they are doing that to work on it but
+because they think it will make Octave code run faster (it never did,
+except for some extremely simple bits of code as examples for
+demonstration purposes only).  The following functions related to the
+JIT compiler have also been removed: `debug_jit`, `jit_enable`,
+`jit_failcnt`, and `jit_startcnt`.
+
 ### Old release news
 
 - [Octave 6.x](etc/NEWS.6)