Protect internal symbols from uninterning.

Issue: TXR holds numerous symbol references in global
variables, like list_s. These variables are not registered as
root pointers with the garbage collector. This is normally
okay because symbols are reachable via packages. However,
if such a symbol is uninterned, that causes an integrity problem.

Solution: protect those symbols from being removed from their
packages.

* Makefile (OBJS): Add protsym.o.

* genprotsym.txr, protsym.c: New files.

* lib.c (prot_sym_check): New static function.
(use_sym, uintern, rehome_sym): Use prot_sym_check to
implement a defense against internal symbols being booted
out of their package.

1 files changed, 209 insertions, 0 deletions

diff --git a/protsym.c b/protsym.c
new file mode 100644
index 00000000..e02d1e23
--- /dev/null
+++ b/protsym.c
@@ -0,0 +1,209 @@
+/* This file is generated by genprotsym.txr */
+
+/* Copyright 2009-2017
+ * Kaz Kylheku <kaz@kylheku.com>
+ * Vancouver, Canada
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stddef.h>
+#include "config.h"
+#include "lib.h"
+
+extern val accept_s, addr_k, addr_s, addrinfo_s, all_s;
+extern val and_s, ap_s, apf_s, append_each_s, append_each_star_s;
+extern val append_k, append_s, apply_s, aret_s, args_k;
+extern val assert_s, atime_k, atime_s, atom_s, auto_k;
+extern val bignum_s, bind_s, blksize_k, blksize_s, block_s;
+extern val block_star_s, blocks_k, blocks_s, byte_oriented_k, call_s;
+extern val canonname_s, car_s, caseq_s, caseq_star_s, caseql_s;
+extern val caseql_star_s, casequal_s, casequal_star_s, cases_s, cat_s;
+extern val catch_s, cc_s, cdigit_k, cdr_s, cflag_s;
+extern val chain_s, chand_s, chars_k, choose_s, chr_s;
+extern val chset_s, circref_s, close_s, cobj_s, coll_s;
+extern val collect_each_s, collect_each_star_s, collect_s, colon_k, compl_s;
+extern val compound_s, cond_s, cons_s, continue_k, continue_s;
+extern val counter_k, cptr_s, cset_s, cspace_k, ctime_k;
+extern val ctime_s, cword_char_k, data_s, day_s, debug_quit_s;
+extern val decline_k, defex_s, deffilter_s, define_s, defmacro_s;
+extern val defparm_s, defparml_s, defr_warning_s, defsymacro_s, defun_s;
+extern val defvar_s, defvarl_s, dev_k, dev_s, digit_k;
+extern val dir_s, do_s, dohash_s, domainname_s, downcase_k;
+extern val dst_s, dvbind_s, dwim_s, each_op_s, each_s;
+extern val each_star_s, empty_s, env_k, env_s, eof_s;
+extern val eol_s, eq_s, eql_s, equal_based_k, equal_s;
+extern val error_s, eval_error_s, expr_s, fail_s, family_s;
+extern val fbind_s, fd_k, file_error_s, filter_k, filter_s;
+extern val finally_s, finish_k, first_s, fixnum_s, flags_s;
+extern val flatten_s, flet_s, float_s, flow_info_s, for_op_s;
+extern val for_s, for_star_s, force_s, forget_s, form_k;
+extern val format_s, freeform_s, from_current_k, from_end_k, from_list_s;
+extern val from_start_k, frombase64_k, fromhtml_k, frompercent_k, fromurl_k;
+extern val fun_k, fun_s, fuzz_s, gap_k, gather_s;
+extern val gecos_s, gen_s, generate_s, gensym_counter_s, gid_k;
+extern val gid_s, gmtoff_s, greedy_k, group_s, gun_s;
+extern val handler_bind_s, hash_construct_s, hash_iter_s, hash_lit_s, hash_s;
+extern val hextoint_k, hour_s, iapply_s, identity_s, if_s;
+extern val iflag_s, iflet_s, in_package_s, inc_s, include_s;
+extern val ino_k, ino_s, integer_s, internal_error_s, into_k;
+extern val intr_s, ipf_s, ispeed_s, keyword_package_s, labels_s;
+extern val lambda_s, lambda_set_s, last_s, lbind_s, lcons_s;
+extern val let_s, let_star_s, lfilt_k, lflag_s, line_s;
+extern val lines_k, lisp1_setq_s, list_k, list_s, list_star_s;
+extern val listener_hist_len_s, listener_multi_line_p_s, listener_sel_inclusive_p_s, lit_s, load_path_s;
+extern val load_recursive_s, load_s, local_s, longest_k, lstr_s;
+extern val mac_param_bind_s, machine_s, macro_s, macro_time_s, macrolet_s;
+extern val make_struct_lit_s, mandatory_k, maxgap_k, maxtimes_k, maybe_s;
+extern val mdo_s, mem_s, memq_s, memql_s, memqual_s;
+extern val merge_s, meth_s, min_s, mingap_k, mintimes_k;
+extern val mod_s, mode_k, mode_s, modlast_s, month_s;
+extern val mtime_k, mtime_s, name_k, name_s, named_k;
+extern val next_s, next_spec_k, nlink_k, nlink_s, nodename_s;
+extern val none_s, nongreedy_s, not_s, nothrow_k, noval_s;
+extern val null_s, nullify_s, number_s, numeric_error_s, oand_s;
+extern val oflag_s, oneplus_s, op_s, opip_s, optional_s;
+extern val or_s, ospeed_s, output_s, package_alist_s, package_s;
+extern val panic_s, parser_s, passwd_s, path_s, pkg_s;
+extern val plus_s, port_s, print_base_s, print_circle_s, print_flo_digits_s;
+extern val print_flo_format_s, print_flo_precision_s, print_s, prio_k, process_error_s;
+extern val prof_s, prog1_s, progn_s, promise_forced_s, promise_inprogress_s;
+extern val promise_s, protocol_s, qquote_s, qref_s, quasi_s;
+extern val quasilist_s, query_error_s, quote_s, random_state_s, random_state_var_s;
+extern val random_warmup_s, range_error_s, range_s, rcons_s, rdev_k;
+extern val rdev_s, real_time_k, rebind_s, reflect_k, regex_s;
+extern val release_s, rep_s, repeat_s, repeat_spec_k, require_s;
+extern val resolve_k, rest_s, restart_s, ret_s, return_from_s;
+extern val return_s, rfilt_k, scope_id_s, sec_s, sequence_s;
+extern val set_s, setq_s, setqf_s, shell_s, shortest_k;
+extern val single_s, size_k, size_s, skip_s, slot_s;
+extern val sockaddr_in6_s, sockaddr_in_s, sockaddr_un_s, socket_error_s, socktype_s;
+extern val some_s, space_k, special_s, splice_s, stat_s;
+extern val static_slot_s, stddebug_s, stderr_s, stdin_s, stdio_stream_s;
+extern val stdnull_s, stdout_s, str_s, stream_s, string_k;
+extern val string_s, struct_lit_s, struct_type_s, switch_s, sym_s;
+extern val symacro_k, symacrolet_s, syntax_error_s, sys_abscond_from_s, sys_apply_s;
+extern val sys_catch_s, sys_lisp1_value_s, sys_mark_special_s, sys_qquote_s, sys_splice_s;
+extern val sys_unquote_s, sysname_s, system_error_s, system_package_s, termios_s;
+extern val text_s, throw_s, time_local_s, time_parse_s, time_s;
+extern val time_string_s, time_utc_s, timeout_error_s, times_k, tlist_k;
+extern val tobase64_k, tofloat_k, tohtml_k, tohtml_star_k, toint_k;
+extern val tonumber_k, topercent_k, tourl_k, trailer_s, tree_bind_s;
+extern val tree_case_s, try_s, type_error_s, uid_k, uid_s;
+extern val unbound_s, unique_s, unquote_s, until_s, until_star_s;
+extern val upcase_k, uref_s, user_package_s, userdata_k, utsname_s;
+extern val uw_protect_s, var_k, var_s, vars_k, vec_list_s;
+extern val vec_s, vecref_s, vector_lit_s, version_s, warning_s;
+extern val weak_keys_k, weak_vals_k, when_s, while_s, while_star_s;
+extern val whole_k, wild_s, with_dyn_rebinds_s, word_char_k, wrap_k;
+extern val year_s, zap_s, zeroplus_s, zone_s;
+
+val *protected_sym[] = {
+  &accept_s, &addr_k, &addr_s, &addrinfo_s, &all_s,
+  &and_s, &ap_s, &apf_s, &append_each_s, &append_each_star_s,
+  &append_k, &append_s, &apply_s, &aret_s, &args_k,
+  &assert_s, &atime_k, &atime_s, &atom_s, &auto_k,
+  &bignum_s, &bind_s, &blksize_k, &blksize_s, &block_s,
+  &block_star_s, &blocks_k, &blocks_s, &byte_oriented_k, &call_s,
+  &canonname_s, &car_s, &caseq_s, &caseq_star_s, &caseql_s,
+  &caseql_star_s, &casequal_s, &casequal_star_s, &cases_s, &cat_s,
+  &catch_s, &cc_s, &cdigit_k, &cdr_s, &cflag_s,
+  &chain_s, &chand_s, &chars_k, &choose_s, &chr_s,
+  &chset_s, &circref_s, &close_s, &cobj_s, &coll_s,
+  &collect_each_s, &collect_each_star_s, &collect_s, &colon_k, &compl_s,
+  &compound_s, &cond_s, &cons_s, &continue_k, &continue_s,
+  &counter_k, &cptr_s, &cset_s, &cspace_k, &ctime_k,
+  &ctime_s, &cword_char_k, &data_s, &day_s, &debug_quit_s,
+  &decline_k, &defex_s, &deffilter_s, &define_s, &defmacro_s,
+  &defparm_s, &defparml_s, &defr_warning_s, &defsymacro_s, &defun_s,
+  &defvar_s, &defvarl_s, &dev_k, &dev_s, &digit_k,
+  &dir_s, &do_s, &dohash_s, &domainname_s, &downcase_k,
+  &dst_s, &dvbind_s, &dwim_s, &each_op_s, &each_s,
+  &each_star_s, &empty_s, &env_k, &env_s, &eof_s,
+  &eol_s, &eq_s, &eql_s, &equal_based_k, &equal_s,
+  &error_s, &eval_error_s, &expr_s, &fail_s, &family_s,
+  &fbind_s, &fd_k, &file_error_s, &filter_k, &filter_s,
+  &finally_s, &finish_k, &first_s, &fixnum_s, &flags_s,
+  &flatten_s, &flet_s, &float_s, &flow_info_s, &for_op_s,
+  &for_s, &for_star_s, &force_s, &forget_s, &form_k,
+  &format_s, &freeform_s, &from_current_k, &from_end_k, &from_list_s,
+  &from_start_k, &frombase64_k, &fromhtml_k, &frompercent_k, &fromurl_k,
+  &fun_k, &fun_s, &fuzz_s, &gap_k, &gather_s,
+  &gecos_s, &gen_s, &generate_s, &gensym_counter_s, &gid_k,
+  &gid_s, &gmtoff_s, &greedy_k, &group_s, &gun_s,
+  &handler_bind_s, &hash_construct_s, &hash_iter_s, &hash_lit_s, &hash_s,
+  &hextoint_k, &hour_s, &iapply_s, &identity_s, &if_s,
+  &iflag_s, &iflet_s, &in_package_s, &inc_s, &include_s,
+  &ino_k, &ino_s, &integer_s, &internal_error_s, &into_k,
+  &intr_s, &ipf_s, &ispeed_s, &keyword_package_s, &labels_s,
+  &lambda_s, &lambda_set_s, &last_s, &lbind_s, &lcons_s,
+  &let_s, &let_star_s, &lfilt_k, &lflag_s, &line_s,
+  &lines_k, &lisp1_setq_s, &list_k, &list_s, &list_star_s,
+  &listener_hist_len_s, &listener_multi_line_p_s, &listener_sel_inclusive_p_s, &lit_s, &load_path_s,
+  &load_recursive_s, &load_s, &local_s, &longest_k, &lstr_s,
+  &mac_param_bind_s, &machine_s, &macro_s, &macro_time_s, &macrolet_s,
+  &make_struct_lit_s, &mandatory_k, &maxgap_k, &maxtimes_k, &maybe_s,
+  &mdo_s, &mem_s, &memq_s, &memql_s, &memqual_s,
+  &merge_s, &meth_s, &min_s, &mingap_k, &mintimes_k,
+  &mod_s, &mode_k, &mode_s, &modlast_s, &month_s,
+  &mtime_k, &mtime_s, &name_k, &name_s, &named_k,
+  &next_s, &next_spec_k, &nlink_k, &nlink_s, &nodename_s,
+  &none_s, &nongreedy_s, &not_s, &nothrow_k, &noval_s,
+  &null_s, &nullify_s, &number_s, &numeric_error_s, &oand_s,
+  &oflag_s, &oneplus_s, &op_s, &opip_s, &optional_s,
+  &or_s, &ospeed_s, &output_s, &package_alist_s, &package_s,
+  &panic_s, &parser_s, &passwd_s, &path_s, &pkg_s,
+  &plus_s, &port_s, &print_base_s, &print_circle_s, &print_flo_digits_s,
+  &print_flo_format_s, &print_flo_precision_s, &print_s, &prio_k, &process_error_s,
+  &prof_s, &prog1_s, &progn_s, &promise_forced_s, &promise_inprogress_s,
+  &promise_s, &protocol_s, &qquote_s, &qref_s, &quasi_s,
+  &quasilist_s, &query_error_s, &quote_s, &random_state_s, &random_state_var_s,
+  &random_warmup_s, &range_error_s, &range_s, &rcons_s, &rdev_k,
+  &rdev_s, &real_time_k, &rebind_s, &reflect_k, &regex_s,
+  &release_s, &rep_s, &repeat_s, &repeat_spec_k, &require_s,
+  &resolve_k, &rest_s, &restart_s, &ret_s, &return_from_s,
+  &return_s, &rfilt_k, &scope_id_s, &sec_s, &sequence_s,
+  &set_s, &setq_s, &setqf_s, &shell_s, &shortest_k,
+  &single_s, &size_k, &size_s, &skip_s, &slot_s,
+  &sockaddr_in6_s, &sockaddr_in_s, &sockaddr_un_s, &socket_error_s, &socktype_s,
+  &some_s, &space_k, &special_s, &splice_s, &stat_s,
+  &static_slot_s, &stddebug_s, &stderr_s, &stdin_s, &stdio_stream_s,
+  &stdnull_s, &stdout_s, &str_s, &stream_s, &string_k,
+  &string_s, &struct_lit_s, &struct_type_s, &switch_s, &sym_s,
+  &symacro_k, &symacrolet_s, &syntax_error_s, &sys_abscond_from_s, &sys_apply_s,
+  &sys_catch_s, &sys_lisp1_value_s, &sys_mark_special_s, &sys_qquote_s, &sys_splice_s,
+  &sys_unquote_s, &sysname_s, &system_error_s, &system_package_s, &termios_s,
+  &text_s, &throw_s, &time_local_s, &time_parse_s, &time_s,
+  &time_string_s, &time_utc_s, &timeout_error_s, &times_k, &tlist_k,
+  &tobase64_k, &tofloat_k, &tohtml_k, &tohtml_star_k, &toint_k,
+  &tonumber_k, &topercent_k, &tourl_k, &trailer_s, &tree_bind_s,
+  &tree_case_s, &try_s, &type_error_s, &uid_k, &uid_s,
+  &unbound_s, &unique_s, &unquote_s, &until_s, &until_star_s,
+  &upcase_k, &uref_s, &user_package_s, &userdata_k, &utsname_s,
+  &uw_protect_s, &var_k, &var_s, &vars_k, &vec_list_s,
+  &vec_s, &vecref_s, &vector_lit_s, &version_s, &warning_s,
+  &weak_keys_k, &weak_vals_k, &when_s, &while_s, &while_star_s,
+  &whole_k, &wild_s, &with_dyn_rebinds_s, &word_char_k, &wrap_k,
+  &year_s, &zap_s, &zeroplus_s, &zone_s,
+  convert(val *, 0)
+};