The long production line on which products of Inform are built, one step at a time.
§1. Having seen the top management of the factory, we now reach the factory floor, which is one long production line: around 130 steps must be performed in sequence to finish making the product. We can picture each of these steps as carried out by a worker function: each does its work and passes on to the next.
130 is a great many, so we group the stages into 12 departments, which are, in order of when they work:
enum SUBDIVIDING_CSEQ from 0 enum BUILT_IN_STUFF_CSEQ enum SEMANTIC_ANALYSIS_CSEQ enum ASSERTIONS_PASS_1_CSEQ enum ASSERTIONS_PASS_2_CSEQ enum MODEL_CSEQ enum MODEL_COMPLETE_CSEQ enum TABLES_CSEQ enum PHRASES_CSEQ enum INTER_CSEQ enum BIBLIOGRAPHIC_CSEQ enum FINISHED_CSEQ
§2. The aim of this section is to contain as little logic as possible. However, a few of the steps are carried out only if debugging features are enabled, or disabled; or only if certain elements of the Inform language are enabled. For example, a Basic Inform source text is not allowed to contain command parser grammar in the way that an IF source text would, so the steps to do with building that grammar are skipped unless the relevant language element is active.
int Sequence::carry_out(int debugging) { stopwatch_timer *sequence_timer = Time::start_stopwatch(inform7_timer, I"compilation to Inter"); Divide into compilation units2.2; Build a rudimentary set of kinds, relations, verbs and inference subjects2.3; Pass three times through the major nodes2.4; Make the model world2.5; Tables and grammar2.6; Phrases and rules2.7; Generate inter2.8; Generate index and bibliographic file2.9; Task::advance_stage_to(FINISHED_CSEQ, I"Ccmplete", -1); int cpu_time_used = Time::stop_stopwatch(sequence_timer); LOG("Compile CPU time: %d centiseconds\n", cpu_time_used); if (problem_count > 0) return FALSE; return TRUE; }
§2.1. Here are macros for the unconditional and conditional steps, respectively, taking place at what we think of as benches in the production line. Continuing the analogy, there is an ongoing time and motion study: any step which takes more than 1 centisecond of CPU time is reported to the debugging log. That isn't necessarily a sign of something wrong: a few of these steps are always going to take serious computation. But we want to know which ones.
As soon as any step generates problem messages, all subsequent steps are skipped, so that each of the worker functions can assume that the part-assembled state they receive is correct so far. This greatly simplifies error recovery, prevents small errors in the source text leading to cascades of problem messages, and ensures that we report problems as quickly as possible.
define BENCH(routine) { if (problem_count == 0) { TEMPORARY_TEXT(name) WRITE_TO(name, "//"); WRITE_TO(name, #routine); WRITE_TO(name, "//"); for (int i=0; i<Str::len(name)-1; i++) if ((Str::get_at(name, i) == '_') && (Str::get_at(name, i+1) == '_')) { Str::put_at(name, i, ':'); Str::put_at(name, i+1, ':'); } stopwatch_timer *st = Time::start_stopwatch(sequence_timer, name); DISCARD_TEXT(name) routine(); int cs = Time::stop_stopwatch(st); if (cs > 0) LOG(".... " #routine "() took %dcs\n", cs); } } define BENCH_IF(plugin, routine) { if ((problem_count == 0) && (Plugins::Manage::plugged_in(plugin))) { TEMPORARY_TEXT(name) WRITE_TO(name, "//"); WRITE_TO(name, #routine); WRITE_TO(name, "//"); for (int i=0; i<Str::len(name)-1; i++) if ((Str::get_at(name, i) == '_') && (Str::get_at(name, i+1) == '_')) { Str::put_at(name, i, ':'); Str::put_at(name, i+1, ':'); } stopwatch_timer *st = Time::start_stopwatch(sequence_timer, name); DISCARD_TEXT(name) routine(); int cs = Time::stop_stopwatch(st); if (cs > 0) LOG(".... " #routine "() took %dcs\n", cs); } }
§2.2. Here, then, are the steps in the production line, presented without commentary. For what they do, see the relevant sections. Note that although most of these worker functions are in the core module, some are not.
Before anything else can be done, we must create an empty Inter hierarchy into which we will "emit" an Inter program. No actual code will be emitted for some time yet, but identifier names and type declarations need somewhere to go. We then break the source into "compilation units" — basically, one for the main source text and one for each extension — because the Inter hierarchy will divide according to these units.
Divide into compilation units2.2 =
Task::advance_stage_to(SUBDIVIDING_CSEQ, I"Dividing source into compilation units", -1); BENCH(CompilationSettings::initialise_gcs) BENCH(Emit::begin); BENCH(Sentences::Headings::make_the_tree) BENCH(Sentences::Headings::write_as_xml) BENCH(CompilationUnits::determine)
- This code is used in §2.
§2.3. Most of the conceptual infrastructure in Inform is created by Inform source text in the Basic Inform or Standard Rules extensions, but not basic kinds of value such as "number", or the verb "to mean", or the meaning relation, and so on. Those absolute basics are made here.
Build a rudimentary set of kinds, relations, verbs and inference subjects2.3 =
Task::advance_stage_to(BUILT_IN_STUFF_CSEQ, I"Making built in infrastructure", -1); BENCH(InferenceSubjects::make_built_in); BENCH(Task::make_built_in_kind_constructors); BENCH(BinaryPredicateFamilies::first_stock) BENCH(BootVerbs::make_built_in)
- This code is used in §2.
§2.4. Pass three times through the major nodes2.4 =
Task::advance_stage_to(SEMANTIC_ANALYSIS_CSEQ, I"Pre-pass through major nodes", 1); BENCH(MajorNodes::pre_pass) BENCH(ParseTreeUsage::verify) Task::advance_stage_to(ASSERTIONS_PASS_1_CSEQ, I"First pass through major nodes", 2); BENCH(MajorNodes::pass_1) BENCH(Tables::traverse_to_stock) Task::advance_stage_to(ASSERTIONS_PASS_2_CSEQ, I"Second pass through major nodes", -1); BENCH(MajorNodes::pass_2)
- This code is used in §2.
§2.5. Make the model world2.5 =
Task::advance_stage_to(MODEL_CSEQ, I"Making the model world", -1); BENCH(Kinds::RunTime::kind_declarations) BENCH(RTUseOptions::compile) BENCH(Properties::emit) BENCH(Properties::Emit::allocate_attributes) BENCH(PL::Actions::name_all) BENCH(UseNouns::name_all) BENCH(Instances::place_objects_in_definition_sequence) Task::advance_stage_to(MODEL_COMPLETE_CSEQ, I"Completing the model world", -1); BENCH(World::complete)
- This code is used in §2.
Task::advance_stage_to(TABLES_CSEQ, I"Tables and grammar", -1); BENCH(Properties::Measurement::validate_definitions) BENCH(BinaryPredicateFamilies::second_stock) BENCH(PL::Bibliographic::IFID::define_UUID) BENCH(PL::Figures::compile_ResourceIDsOfFigures_array) BENCH(PL::Sounds::compile_ResourceIDsOfSounds_array) BENCH(PL::Player::InitialSituation) BENCH(Tables::check_tables_for_kind_clashes) BENCH(Tables::Support::compile_print_table_names) BENCH(PL::Parsing::traverse) BENCH(World::complete_additions)
- This code is used in §2.
Task::advance_stage_to(PHRASES_CSEQ, I"Phrases and rules", 3); BENCH(LiteralPatterns::define_named_phrases) BENCH(Phrases::Manager::traverse) BENCH(Phrases::Manager::register_meanings) BENCH(Phrases::Manager::parse_rule_parameters) BENCH(Phrases::Manager::add_rules_to_rulebooks) BENCH(Phrases::Manager::parse_rule_placements) BENCH(Equations::traverse_to_stock) BENCH(Tables::traverse_to_stock) BENCH(Properties::annotate_attributes) BENCH(Rulebooks::Outcomes::RulebookOutcomePrintingRule) BENCH(Kinds::RunTime::compile_instance_counts)
- This code is used in §2.
Task::advance_stage_to(INTER_CSEQ, I"Generating inter", 4); BENCH(RTUseOptions::compile_pragmas) BENCH(FundamentalConstants::emit_build_number) BENCH(PL::Bibliographic::compile_constants) BENCH(Extensions::Files::ShowExtensionVersions_routine) BENCH(Kinds::Constructors::emit_constants) BENCH_IF(scoring_plugin, PL::Score::compile_max_score) BENCH(RTUseOptions::TestUseOption_routine) BENCH(Activities::compile_activity_constants) BENCH(Activities::Activity_before_rulebooks_array) BENCH(Activities::Activity_for_rulebooks_array) BENCH(Activities::Activity_after_rulebooks_array) BENCH(Activities::Activity_atb_rulebooks_array) BENCH(Relations::compile_defined_relation_constants) BENCH(Kinds::RunTime::compile_data_type_support_routines) BENCH(Kinds::RunTime::I7_Kind_Name_routine) BENCH(World::Compile::compile) BENCH_IF(backdrops_plugin, PL::Backdrops::write_found_in_routines) BENCH_IF(map_plugin, PL::Map::write_door_dir_routines) BENCH_IF(map_plugin, PL::Map::write_door_to_routines) BENCH_IF(parsing_plugin, PL::Parsing::Tokens::General::write_parse_name_routines) BENCH_IF(regions_plugin, PL::Regions::write_regional_found_in_routines) BENCH(Tables::complete) BENCH(Tables::Support::compile) BENCH(Equations::compile) BENCH_IF(actions_plugin, PL::Actions::Patterns::Named::compile) BENCH_IF(actions_plugin, PL::Actions::ActionData) BENCH_IF(actions_plugin, PL::Actions::ActionCoding_array) BENCH_IF(actions_plugin, PL::Actions::ActionHappened) BENCH_IF(actions_plugin, PL::Actions::compile_action_routines) BENCH_IF(parsing_plugin, PL::Parsing::Lines::MistakeActionSub_routine) BENCH(Phrases::Manager::compile_first_block) BENCH(Phrases::Manager::compile_rulebooks) BENCH(Phrases::Manager::rulebooks_array) BENCH_IF(scenes_plugin, PL::Scenes::DetectSceneChange_routine) BENCH_IF(scenes_plugin, PL::Scenes::ShowSceneStatus_routine) BENCH(PL::Files::arrays) BENCH(Rulebooks::rulebook_var_creators) BENCH(Activities::activity_var_creators) BENCH(Relations::IterateRelations) BENCH(Phrases::Manager::RulebookNames_array) BENCH(Phrases::Manager::RulePrintingRule_routine) BENCH_IF(parsing_plugin, PL::Parsing::Verbs::prepare) BENCH_IF(parsing_plugin, PL::Parsing::Verbs::compile_conditions) BENCH_IF(parsing_plugin, PL::Parsing::Tokens::Values::number) BENCH_IF(parsing_plugin, PL::Parsing::Tokens::Values::truth_state) BENCH_IF(parsing_plugin, PL::Parsing::Tokens::Values::time) BENCH_IF(parsing_plugin, PL::Parsing::Tokens::Values::compile_type_gprs) BENCH(VerbsAtRunTime::ConjugateVerb) BENCH(Adjectives::Meanings::agreements) if (debugging) { BENCH_IF(parsing_plugin, PL::Parsing::TestScripts::write_text) BENCH_IF(parsing_plugin, PL::Parsing::TestScripts::TestScriptSub_routine) BENCH(InternalTests::InternalTestCases_routine) } else { BENCH_IF(parsing_plugin, PL::Parsing::TestScripts::TestScriptSub_stub_routine) } BENCH(Lists::check) BENCH(Lists::compile) BENCH(Phrases::invoke_to_begin) BENCH(Phrases::Manager::compile_as_needed) BENCH(Strings::compile_responses) BENCH(Lists::check) BENCH(Lists::compile) BENCH(Relations::compile_defined_relations) BENCH(Phrases::Manager::compile_as_needed) BENCH(Strings::TextSubstitutions::allow_no_further_text_subs) BENCH_IF(parsing_plugin, PL::Parsing::Tokens::Filters::compile) BENCH_IF(actions_plugin, Chronology::past_actions_i6_routines) BENCH_IF(chronology_plugin, Chronology::chronology_extents_i6_escape) BENCH_IF(chronology_plugin, Chronology::past_tenses_i6_escape) BENCH_IF(chronology_plugin, Chronology::allow_no_further_past_tenses) BENCH_IF(parsing_plugin, PL::Parsing::Verbs::compile_all) BENCH_IF(parsing_plugin, PL::Parsing::Tokens::Filters::compile) BENCH(Properties::Measurement::compile_MADJ_routines) BENCH(Propositions::Deferred::compile_remaining_deferred) BENCH(Calculus::Deferrals::allow_no_further_deferrals) BENCH(Lists::check) BENCH(Lists::compile) BENCH(Strings::TextLiterals::compile) BENCH(JumpLabels::compile_necessary_storage) BENCH(Kinds::RunTime::compile_heap_allocator) BENCH(Phrases::Constants::compile_closures) BENCH(Kinds::RunTime::compile_structures) BENCH(Rules::check_response_usages) BENCH(Phrases::Timed::check_for_unused) BENCH(PL::Showme::compile_SHOWME_details) BENCH(Phrases::Timed::TimedEventsTable) BENCH(Phrases::Timed::TimedEventTimesTable) BENCH(PL::Naming::compile_cap_short_name) BENCH(RTUseOptions::configure_template)
- This code is used in §2.
§2.9. Generate index and bibliographic file2.9 =
Task::advance_stage_to(BIBLIOGRAPHIC_CSEQ, I"Bibliographic work", -1); BENCH_IF(bibliographic_plugin, PL::Bibliographic::Release::write_ifiction_and_blurb); BENCH(I6T::produce_index);
- This code is used in §2.