about summary refs log tree commit diff stats
path: root/archive/1.vm/050scenario.cc
diff options
context:
space:
mode:
Diffstat (limited to 'archive/1.vm/050scenario.cc')
-rw-r--r--archive/1.vm/050scenario.cc1039
1 files changed, 1039 insertions, 0 deletions
diff --git a/archive/1.vm/050scenario.cc b/archive/1.vm/050scenario.cc
new file mode 100644
index 00000000..5b9dcc14
--- /dev/null
+++ b/archive/1.vm/050scenario.cc
@@ -0,0 +1,1039 @@
+//: Mu scenarios. This will get long, but these are the tests we want to
+//: support in this layer.
+
+//: We avoid raw numeric locations in Mu -- except in scenarios, where they're
+//: handy to check the values of specific variables
+
+void test_scenario_block() {
+  run_mu_scenario(
+      "scenario foo [\n"
+      "  run [\n"
+      "    1:num <- copy 13\n"
+      "  ]\n"
+      "  memory-should-contain [\n"
+      "    1 <- 13\n"
+      "  ]\n"
+      "]\n"
+  );
+  // checks are inside scenario
+}
+
+void test_scenario_multiple_blocks() {
+  run_mu_scenario(
+      "scenario foo [\n"
+      "  run [\n"
+      "    1:num <- copy 13\n"
+      "  ]\n"
+      "  memory-should-contain [\n"
+      "    1 <- 13\n"
+      "  ]\n"
+      "  run [\n"
+      "    2:num <- copy 13\n"
+      "  ]\n"
+      "  memory-should-contain [\n"
+      "    1 <- 13\n"
+      "    2 <- 13\n"
+      "  ]\n"
+      "]\n"
+  );
+  // checks are inside scenario
+}
+
+void test_scenario_check_memory_and_trace() {
+  run_mu_scenario(
+      "scenario foo [\n"
+      "  run [\n"
+      "    1:num <- copy 13\n"
+      "    trace 1, [a], [a b c]\n"
+      "  ]\n"
+      "  memory-should-contain [\n"
+      "    1 <- 13\n"
+      "  ]\n"
+      "  trace-should-contain [\n"
+      "    a: a b c\n"
+      "  ]\n"
+      "  trace-should-not-contain [\n"
+      "    a: x y z\n"
+      "  ]\n"
+      "]\n"
+  );
+  // checks are inside scenario
+}
+
+//:: Core data structure
+
+:(before "End Types")
+struct scenario {
+  string name;
+  string to_run;
+  void clear() {
+    name.clear();
+    to_run.clear();
+  }
+};
+
+:(before "End Globals")
+vector<scenario> Scenarios, Scenarios_snapshot;
+set<string> Scenario_names, Scenario_names_snapshot;
+:(before "End save_snapshots")
+Scenarios_snapshot = Scenarios;
+Scenario_names_snapshot = Scenario_names;
+:(before "End restore_snapshots")
+Scenarios = Scenarios_snapshot;
+Scenario_names = Scenario_names_snapshot;
+
+//:: Parse the 'scenario' form.
+//: Simply store the text of the scenario.
+
+:(before "End Command Handlers")
+else if (command == "scenario") {
+  scenario result = parse_scenario(in);
+  if (!result.name.empty())
+    Scenarios.push_back(result);
+}
+else if (command == "pending-scenario") {
+  // for temporary use only
+  parse_scenario(in);  // discard
+}
+
+:(code)
+scenario parse_scenario(istream& in) {
+  scenario result;
+  result.name = next_word(in);
+  if (contains_key(Scenario_names, result.name))
+    raise << "duplicate scenario name: '" << result.name << "'\n" << end();
+  Scenario_names.insert(result.name);
+  if (result.name.empty()) {
+    assert(!has_data(in));
+    raise << "incomplete scenario at end of file\n" << end();
+    return result;
+  }
+  skip_whitespace_and_comments(in);
+  if (in.peek() != '[') {
+    raise << "Expected '[' after scenario '" << result.name << "'\n" << end();
+    exit(0);
+  }
+  // scenarios are take special 'code' strings so we need to ignore brackets
+  // inside comments
+  result.to_run = slurp_quoted(in);
+  // delete [] delimiters
+  if (!starts_with(result.to_run, "[")) {
+    raise << "scenario " << result.name << " should start with '['\n" << end();
+    result.clear();
+    return result;
+  }
+  result.to_run.erase(0, 1);
+  if (result.to_run.at(SIZE(result.to_run)-1) != ']') {
+    raise << "scenario " << result.name << " has an unbalanced '['\n" << end();
+    result.clear();
+    return result;
+  }
+  result.to_run.erase(SIZE(result.to_run)-1);
+  return result;
+}
+
+void test_read_scenario_with_bracket_in_comment() {
+  run_mu_scenario(
+      "scenario foo [\n"
+      "  # ']' in comment\n"
+      "  1:num <- copy 0\n"
+      "]\n"
+  );
+  CHECK_TRACE_CONTENTS(
+      "run: {1: \"number\"} <- copy {0: \"literal\"}\n"
+  );
+}
+
+void test_read_scenario_with_bracket_in_comment_in_nested_string() {
+  run_mu_scenario(
+      "scenario foo [\n"
+      "  1:text <- new [# not a comment]\n"
+      "]\n"
+  );
+  CHECK_TRACE_CONTENTS(
+      "run: {1: (\"address\" \"array\" \"character\")} <- new {\"# not a comment\": \"literal-string\"}\n"
+  );
+}
+
+void test_duplicate_scenarios() {
+  Hide_errors = true;
+  run(
+      "scenario foo [\n"
+      "  1:num <- copy 0\n"
+      "]\n"
+      "scenario foo [\n"
+      "  2:num <- copy 0\n"
+      "]\n"
+  );
+  CHECK_TRACE_CONTENTS(
+      "error: duplicate scenario name: 'foo'\n"
+  );
+}
+
+//:: Run scenarios when we run './mu test'.
+//: Treat the text of the scenario as a regular series of instructions.
+
+:(before "End Globals")
+int Num_core_mu_scenarios = 0;
+:(after "Check For .mu Files")
+Num_core_mu_scenarios = SIZE(Scenarios);
+:(before "End Tests")
+Hide_missing_default_space_errors = false;
+if (Num_core_mu_scenarios > 0) {
+  time(&t);
+  cerr << "Mu tests: " << ctime(&t);
+  for (int i = 0;  i < Num_core_mu_scenarios;  ++i) {
+//?     cerr << '\n' << i << ": " << Scenarios.at(i).name;
+    run_mu_scenario(Scenarios.at(i));
+    if (Passed) cerr << ".";
+    else ++num_failures;
+  }
+  cerr << "\n";
+}
+run_app_scenarios:
+if (Num_core_mu_scenarios != SIZE(Scenarios)) {
+  time(&t);
+  cerr << "App tests: " << ctime(&t);
+  for (int i = Num_core_mu_scenarios;  i < SIZE(Scenarios);  ++i) {
+//?     cerr << '\n' << i << ": " << Scenarios.at(i).name;
+    run_mu_scenario(Scenarios.at(i));
+    if (Passed) cerr << ".";
+    else ++num_failures;
+  }
+  cerr << "\n";
+}
+
+//: For faster debugging, support running tests for just the Mu app(s) we are
+//: loading.
+:(before "End Globals")
+bool Test_only_app = false;
+:(before "End Commandline Options(*arg)")
+else if (is_equal(*arg, "--test-only-app")) {
+  Test_only_app = true;
+}
+:(after "End Test Run Initialization")
+if (Test_only_app && Num_core_mu_scenarios < SIZE(Scenarios)) {
+  goto run_app_scenarios;
+}
+
+//: Convenience: run a single named scenario.
+:(after "Test Runs")
+for (int i = 0;  i < SIZE(Scenarios);  ++i) {
+  if (Scenarios.at(i).name == argv[argc-1]) {
+    run_mu_scenario(Scenarios.at(i));
+    if (Passed) cerr << ".\n";
+    return 0;
+  }
+}
+
+:(before "End Globals")
+// this isn't a constant, just a global of type const*
+const scenario* Current_scenario = NULL;
+:(code)
+void run_mu_scenario(const scenario& s) {
+  Current_scenario = &s;
+  bool not_already_inside_test = !Trace_stream;
+//?   cerr << s.name << '\n';
+  if (not_already_inside_test) {
+    Trace_stream = new trace_stream;
+    reset();
+  }
+  vector<recipe_ordinal> tmp = load("recipe scenario_"+s.name+" [ "+s.to_run+" ]");
+  mark_autogenerated(tmp.at(0));
+  bind_special_scenario_names(tmp.at(0));
+  transform_all();
+  if (!trace_contains_errors())
+    run(tmp.front());
+  // End Mu Test Teardown
+  if (!Hide_errors && trace_contains_errors() && !Scenario_testing_scenario)
+    Passed = false;
+  if (not_already_inside_test && Trace_stream) {
+    delete Trace_stream;
+    Trace_stream = NULL;
+  }
+  Current_scenario = NULL;
+}
+
+//: Permit numeric locations to be accessed in scenarios.
+:(before "End check_default_space Special-cases")
+// user code should never create recipes with underscores in their names
+if (starts_with(caller.name, "scenario_")) return;  // skip Mu scenarios which will use raw memory locations
+if (starts_with(caller.name, "run_")) return;  // skip calls to 'run', which should be in scenarios and will also use raw memory locations
+
+:(before "End maybe(recipe_name) Special-cases")
+if (starts_with(recipe_name, "scenario_"))
+  return recipe_name.substr(strlen("scenario_")) + ": ";
+
+//: Some variables for fake resources always get special /raw addresses in scenarios.
+
+:(code)
+// Should contain everything passed by is_special_name but failed by is_disqualified.
+void bind_special_scenario_names(const recipe_ordinal r) {
+  // Special Scenario Variable Names(r)
+  // End Special Scenario Variable Names(r)
+}
+:(before "Done Placing Ingredient(ingredient, inst, caller)")
+maybe_make_raw(ingredient, caller);
+:(before "Done Placing Product(product, inst, caller)")
+maybe_make_raw(product, caller);
+:(code)
+void maybe_make_raw(reagent& r, const recipe& caller) {
+  if (!is_special_name(r.name)) return;
+  if (starts_with(caller.name, "scenario_"))
+    r.properties.push_back(pair<string, string_tree*>("raw", NULL));
+  // End maybe_make_raw
+}
+
+//: Test with some setup.
+:(before "End is_special_name Special-cases")
+if (s == "__maybe_make_raw_test__") return true;
+:(before "End Special Scenario Variable Names(r)")
+//: ugly: we only need this for this one test, but need to define it for all time
+Name[r]["__maybe_make_raw_test__"] = Reserved_for_tests-1;
+:(code)
+void test_maybe_make_raw() {
+  // check that scenarios can use local-scope and special variables together
+  vector<recipe_ordinal> tmp = load(
+      "def scenario_foo [\n"
+      "  local-scope\n"
+      "  __maybe_make_raw_test__:num <- copy 34\n"
+      "]\n");
+  mark_autogenerated(tmp.at(0));
+  bind_special_scenario_names(tmp.at(0));
+  transform_all();
+  run(tmp.at(0));
+  CHECK_TRACE_DOESNT_CONTAIN_ERRORS();
+}
+
+//: Watch out for redefinitions of scenario routines. We should never ever be
+//: doing that, regardless of anything else.
+
+void test_forbid_redefining_scenario_even_if_forced() {
+  Hide_errors = true;
+  Disable_redefine_checks = true;
+  run(
+      "def scenario-foo [\n"
+      "  1:num <- copy 34\n"
+      "]\n"
+      "def scenario-foo [\n"
+      "  1:num <- copy 35\n"
+      "]\n"
+  );
+  CHECK_TRACE_CONTENTS(
+      "error: redefining recipe scenario-foo\n"
+  );
+}
+
+void test_scenario_containing_parse_error() {
+  Hide_errors = true;
+  run(
+      "scenario foo [\n"
+      "  memory-should-contain [\n"
+      "    1 <- 0\n"
+         // missing ']'
+      "]\n"
+  );
+  // no crash
+}
+
+void test_scenario_containing_transform_error() {
+  Hide_errors = true;
+  run(
+      "def main [\n"
+      "  local-scope\n"
+      "  add x, 1\n"
+      "]\n"
+  );
+  // no crash
+}
+
+:(after "bool should_check_for_redefine(const string& recipe_name)")
+  if (recipe_name.find("scenario-") == 0) return true;
+
+//:: The special instructions we want to support inside scenarios.
+//: These are easy to support in an interpreter, but will require more work
+//: when we eventually build a compiler.
+
+//: 'run' is a purely lexical convenience to separate the code actually being
+//: tested from any setup
+
+:(code)
+void test_run() {
+  run(
+      "def main [\n"
+      "  run [\n"
+      "    1:num <- copy 13\n"
+      "  ]\n"
+      "]\n"
+  );
+  CHECK_TRACE_CONTENTS(
+      "mem: storing 13 in location 1\n"
+  );
+}
+
+:(before "End Rewrite Instruction(curr, recipe result)")
+if (curr.name == "run") {
+  // Just inline all instructions inside the run block in the containing
+  // recipe. 'run' is basically a comment; pretend it doesn't exist.
+  istringstream in2("[\n"+curr.ingredients.at(0).name+"\n]\n");
+  slurp_body(in2, result);
+  curr.clear();
+}
+
+:(code)
+void test_run_multiple() {
+  run(
+      "def main [\n"
+      "  run [\n"
+      "    1:num <- copy 13\n"
+      "  ]\n"
+      "  run [\n"
+      "    2:num <- copy 13\n"
+      "  ]\n"
+      "]\n"
+  );
+  CHECK_TRACE_CONTENTS(
+      "mem: storing 13 in location 1\n"
+      "mem: storing 13 in location 2\n"
+  );
+}
+
+//: 'memory-should-contain' raises errors if specific locations aren't as expected
+//: Also includes some special support for checking Mu texts.
+
+:(before "End Globals")
+bool Scenario_testing_scenario = false;
+:(before "End Reset")
+Scenario_testing_scenario = false;
+
+:(code)
+void test_memory_check() {
+  Scenario_testing_scenario = true;
+  Hide_errors = true;
+  run(
+      "def main [\n"
+      "  memory-should-contain [\n"
+      "    1 <- 13\n"
+      "  ]\n"
+      "]\n"
+  );
+  CHECK_TRACE_CONTENTS(
+      "run: checking location 1\n"
+      "error: F - main: expected location '1' to contain 13 but saw 0\n"
+  );
+}
+
+:(before "End Primitive Recipe Declarations")
+MEMORY_SHOULD_CONTAIN,
+:(before "End Primitive Recipe Numbers")
+put(Recipe_ordinal, "memory-should-contain", MEMORY_SHOULD_CONTAIN);
+:(before "End Primitive Recipe Checks")
+case MEMORY_SHOULD_CONTAIN: {
+  break;
+}
+:(before "End Primitive Recipe Implementations")
+case MEMORY_SHOULD_CONTAIN: {
+  if (!Passed) break;
+  check_memory(current_instruction().ingredients.at(0).name);
+  break;
+}
+
+:(code)
+void check_memory(const string& s) {
+  istringstream in(s);
+  in >> std::noskipws;
+  set<int> locations_checked;
+  while (true) {
+    skip_whitespace_and_comments(in);
+    if (!has_data(in)) break;
+    string lhs = next_word(in);
+    if (lhs.empty()) {
+      assert(!has_data(in));
+      raise << maybe(current_recipe_name()) << "incomplete 'memory-should-contain' block at end of file (0)\n" << end();
+      return;
+    }
+    if (!is_integer(lhs)) {
+      check_type(lhs, in);
+      continue;
+    }
+    int address = to_integer(lhs);
+    skip_whitespace_and_comments(in);
+    string _assign;  in >> _assign;  assert(_assign == "<-");
+    skip_whitespace_and_comments(in);
+    string rhs = next_word(in);
+    if (rhs.empty()) {
+      assert(!has_data(in));
+      raise << maybe(current_recipe_name()) << "incomplete 'memory-should-contain' block at end of file (1)\n" << end();
+      return;
+    }
+    if (!is_integer(rhs) && !is_noninteger(rhs)) {
+      if (!Hide_errors) cerr << '\n';
+      raise << "F - " << maybe(current_recipe_name()) << "location '" << address << "' can't contain non-number " << rhs << '\n' << end();
+      if (!Scenario_testing_scenario) Passed = false;
+      return;
+    }
+    double value = to_double(rhs);
+    if (contains_key(locations_checked, address))
+      raise << maybe(current_recipe_name()) << "duplicate expectation for location '" << address << "'\n" << end();
+    trace(Callstack_depth+1, "run") << "checking location " << address << end();
+    if (get_or_insert(Memory, address) != value) {
+      if (!Hide_errors) cerr << '\n';
+      raise << "F - " << maybe(current_recipe_name()) << "expected location '" << address << "' to contain " << no_scientific(value) << " but saw " << no_scientific(get_or_insert(Memory, address)) << '\n' << end();
+      if (!Scenario_testing_scenario) Passed = false;
+      return;
+    }
+    locations_checked.insert(address);
+  }
+}
+
+void check_type(const string& lhs, istream& in) {
+  reagent x(lhs);
+  if (is_mu_array(x.type) && is_mu_character(array_element(x.type))) {
+    x.set_value(to_integer(x.name));
+    skip_whitespace_and_comments(in);
+    string _assign = next_word(in);
+    if (_assign.empty()) {
+      assert(!has_data(in));
+      raise << maybe(current_recipe_name()) << "incomplete 'memory-should-contain' block at end of file (2)\n" << end();
+      return;
+    }
+    assert(_assign == "<-");
+    skip_whitespace_and_comments(in);
+    string literal = next_word(in);
+    if (literal.empty()) {
+      assert(!has_data(in));
+      raise << maybe(current_recipe_name()) << "incomplete 'memory-should-contain' block at end of file (3)\n" << end();
+      return;
+    }
+    int address = x.value;
+    // exclude quoting brackets
+    if (*literal.begin() != '[') {
+      raise << maybe(current_recipe_name()) << "array:character types inside 'memory-should-contain' can only be compared with text literals surrounded by [], not '" << literal << "'\n" << end();
+      return;
+    }
+    literal.erase(literal.begin());
+    assert(*--literal.end() == ']');  literal.erase(--literal.end());
+    check_mu_text(address, literal);
+    return;
+  }
+  // End Scenario Type Special-cases
+  raise << "don't know how to check memory for '" << lhs << "'\n" << end();
+}
+
+void check_mu_text(int start, const string& literal) {
+  trace(Callstack_depth+1, "run") << "checking text length at " << start << end();
+  int array_length = static_cast<int>(get_or_insert(Memory, start));
+  if (array_length != SIZE(literal)) {
+    if (!Hide_errors) cerr << '\n';
+    raise << "F - " << maybe(current_recipe_name()) << "expected location '" << start << "' to contain length " << SIZE(literal) << " of text [" << literal << "] but saw " << array_length << " (for text [" << read_mu_characters(start+/*skip length*/1, array_length) << "])\n" << end();
+    if (!Scenario_testing_scenario) Passed = false;
+    return;
+  }
+  int curr = start+1;  // now skip length
+  for (int i = 0;  i < SIZE(literal);  ++i) {
+    trace(Callstack_depth+1, "run") << "checking location " << curr+i << end();
+    if (get_or_insert(Memory, curr+i) != literal.at(i)) {
+      if (!Hide_errors) cerr << '\n';
+      raise << "F - " << maybe(current_recipe_name()) << "expected location " << (curr+i) << " to contain " << literal.at(i) << " but saw " << no_scientific(get_or_insert(Memory, curr+i)) << '\n' << end();
+      if (!Scenario_testing_scenario) Passed = false;
+      return;
+    }
+  }
+}
+
+void test_memory_check_multiple() {
+  Scenario_testing_scenario = true;
+  Hide_errors = true;
+  run(
+      "def main [\n"
+      "  memory-should-contain [\n"
+      "    1 <- 0\n"
+      "    1 <- 0\n"
+      "  ]\n"
+      "]\n"
+  );
+  CHECK_TRACE_CONTENTS(
+      "error: main: duplicate expectation for location '1'\n"
+  );
+}
+
+void test_memory_check_mu_text_length() {
+  Scenario_testing_scenario = true;
+  Hide_errors = true;
+  run(
+      "def main [\n"
+      "  1:num <- copy 3\n"
+      "  2:num <- copy 97  # 'a'\n"
+      "  3:num <- copy 98  # 'b'\n"
+      "  4:num <- copy 99  # 'c'\n"
+      "  memory-should-contain [\n"
+      "    1:array:character <- [ab]\n"
+      "  ]\n"
+      "]\n"
+  );
+  CHECK_TRACE_CONTENTS(
+      "error: F - main: expected location '1' to contain length 2 of text [ab] but saw 3 (for text [abc])\n"
+  );
+}
+
+void test_memory_check_mu_text() {
+  run(
+      "def main [\n"
+      "  1:num <- copy 3\n"
+      "  2:num <- copy 97\n"  // 'a'
+      "  3:num <- copy 98\n"  // 'b'
+      "  4:num <- copy 99\n"  // 'c'
+      "  memory-should-contain [\n"
+      "    1:array:character <- [abc]\n"
+      "  ]\n"
+      "]\n"
+  );
+  CHECK_TRACE_CONTENTS(
+      "run: checking text length at 1\n"
+      "run: checking location 2\n"
+      "run: checking location 3\n"
+      "run: checking location 4\n"
+  );
+}
+
+void test_memory_invalid_string_check() {
+  Scenario_testing_scenario = true;
+  Hide_errors = true;
+  run(
+      "def main [\n"
+      "  memory-should-contain [\n"
+      "    1 <- [abc]\n"
+      "  ]\n"
+      "]\n"
+  );
+  CHECK_TRACE_CONTENTS(
+      "error: F - main: location '1' can't contain non-number [abc]\n"
+  );
+}
+
+void test_memory_invalid_string_check2() {
+  Hide_errors = true;
+  run(
+      "def main [\n"
+      "  1:num <- copy 3\n"
+      "  2:num <- copy 97\n"  // 'a'
+      "  3:num <- copy 98\n"  // 'b'
+      "  4:num <- copy 99\n"  // 'c'
+      "  memory-should-contain [\n"
+      "    1:array:character <- 0\n"
+      "  ]\n"
+      "]\n"
+  );
+  CHECK_TRACE_CONTENTS(
+      "error: main: array:character types inside 'memory-should-contain' can only be compared with text literals surrounded by [], not '0'\n"
+  );
+}
+
+void test_memory_check_with_comment() {
+  Scenario_testing_scenario = true;
+  Hide_errors = true;
+  run(
+      "def main [\n"
+      "  memory-should-contain [\n"
+      "    1 <- 34  # comment\n"
+      "  ]\n"
+      "]\n"
+  );
+  CHECK_TRACE_DOESNT_CONTAIN("error: location 1 can't contain non-number 34  # comment");
+  // but there'll be an error signalled by memory-should-contain
+}
+
+//: 'trace-should-contain' is like the '+' lines in our scenarios so far
+//: Like runs of contiguous '+' lines, order is important. The trace checks
+//: that the lines are present *and* in the specified sequence. (There can be
+//: other lines in between.)
+
+void test_trace_check_fails() {
+  Scenario_testing_scenario = true;
+  Hide_errors = true;
+  run(
+      "def main [\n"
+         // nothing added to the trace
+      "  trace-should-contain [\n"
+      "    a: b\n"
+      "    a: d\n"
+      "  ]\n"
+      "]\n"
+  );
+  CHECK_TRACE_CONTENTS(
+      "error: F - main: missing [b] in trace with label 'a'\n"
+  );
+}
+
+:(before "End Primitive Recipe Declarations")
+TRACE_SHOULD_CONTAIN,
+:(before "End Primitive Recipe Numbers")
+put(Recipe_ordinal, "trace-should-contain", TRACE_SHOULD_CONTAIN);
+:(before "End Primitive Recipe Checks")
+case TRACE_SHOULD_CONTAIN: {
+  break;
+}
+:(before "End Primitive Recipe Implementations")
+case TRACE_SHOULD_CONTAIN: {
+  if (!Passed) break;
+  check_trace(current_instruction().ingredients.at(0).name);
+  break;
+}
+
+:(code)
+// simplified version of check_trace_contents() that emits errors rather
+// than just printing to stderr
+void check_trace(const string& expected) {
+  Trace_stream->newline();
+  vector<trace_line> expected_lines = parse_trace(expected);
+  if (expected_lines.empty()) return;
+  int curr_expected_line = 0;
+  for (vector<trace_line>::iterator p = Trace_stream->past_lines.begin();  p != Trace_stream->past_lines.end();  ++p) {
+    if (expected_lines.at(curr_expected_line).label != p->label) continue;
+    if (expected_lines.at(curr_expected_line).contents != trim(p->contents)) continue;
+    // match
+    ++curr_expected_line;
+    if (curr_expected_line == SIZE(expected_lines)) return;
+  }
+  if (!Hide_errors) cerr << '\n';
+  raise << "F - " << maybe(current_recipe_name()) << "missing [" << expected_lines.at(curr_expected_line).contents << "] "
+        << "in trace with label '" << expected_lines.at(curr_expected_line).label << "'\n" << end();
+  if (!Hide_errors)
+    DUMP(expected_lines.at(curr_expected_line).label);
+  if (!Scenario_testing_scenario) Passed = false;
+}
+
+vector<trace_line> parse_trace(const string& expected) {
+  vector<string> buf = split(expected, "\n");
+  vector<trace_line> result;
+  const string separator = ": ";
+  for (int i = 0;  i < SIZE(buf);  ++i) {
+    buf.at(i) = trim(buf.at(i));
+    if (buf.at(i).empty()) continue;
+    int delim = buf.at(i).find(separator);
+    if (delim == -1) {
+      raise << maybe(current_recipe_name()) << "lines in 'trace-should-contain' should be of the form <label>: <contents>. Both parts are required.\n" << end();
+      result.clear();
+      return result;
+    }
+    result.push_back(trace_line(/*contents*/  trim(buf.at(i).substr(delim+SIZE(separator)        )),
+                                /*label*/     trim(buf.at(i).substr(0,                      delim))));
+  }
+  return result;
+}
+
+void test_trace_check_fails_in_nonfirst_line() {
+  Scenario_testing_scenario = true;
+  Hide_errors = true;
+  run(
+      "def main [\n"
+      "  run [\n"
+      "    trace 1, [a], [b]\n"
+      "  ]\n"
+      "  trace-should-contain [\n"
+      "    a: b\n"
+      "    a: d\n"
+      "  ]\n"
+      "]\n"
+  );
+  CHECK_TRACE_CONTENTS(
+      "error: F - main: missing [d] in trace with label 'a'\n"
+  );
+}
+
+void test_trace_check_passes_silently() {
+  Scenario_testing_scenario = true;
+  run(
+      "def main [\n"
+      "  run [\n"
+      "    trace 1, [a], [b]\n"
+      "  ]\n"
+      "  trace-should-contain [\n"
+      "    a: b\n"
+      "  ]\n"
+      "]\n"
+  );
+  CHECK_TRACE_DOESNT_CONTAIN("error: missing [b] in trace with label 'a'");
+  CHECK_TRACE_COUNT("error", 0);
+}
+
+//: 'trace-should-not-contain' checks each line in its argument for absence.
+//: Order is *not* important, so you can't say things like "B should not exist
+//: after A."
+
+void test_trace_negative_check_fails() {
+  Scenario_testing_scenario = true;
+  Hide_errors = true;
+  run(
+      "def main [\n"
+      "  run [\n"
+      "    trace 1, [a], [b]\n"
+      "  ]\n"
+      "  trace-should-not-contain [\n"
+      "    a: b\n"
+      "  ]\n"
+      "]\n"
+  );
+  CHECK_TRACE_CONTENTS(
+      "error: F - main: unexpected [b] in trace with label 'a'\n"
+  );
+}
+
+:(before "End Primitive Recipe Declarations")
+TRACE_SHOULD_NOT_CONTAIN,
+:(before "End Primitive Recipe Numbers")
+put(Recipe_ordinal, "trace-should-not-contain", TRACE_SHOULD_NOT_CONTAIN);
+:(before "End Primitive Recipe Checks")
+case TRACE_SHOULD_NOT_CONTAIN: {
+  break;
+}
+:(before "End Primitive Recipe Implementations")
+case TRACE_SHOULD_NOT_CONTAIN: {
+  if (!Passed) break;
+  check_trace_missing(current_instruction().ingredients.at(0).name);
+  break;
+}
+
+:(code)
+// simplified version of check_trace_contents() that emits errors rather
+// than just printing to stderr
+bool check_trace_missing(const string& in) {
+  Trace_stream->newline();
+  vector<trace_line> lines = parse_trace(in);
+  for (int i = 0;  i < SIZE(lines);  ++i) {
+    if (trace_count(lines.at(i).label, lines.at(i).contents) != 0) {
+      raise << "F - " << maybe(current_recipe_name()) << "unexpected [" << lines.at(i).contents << "] in trace with label '" << lines.at(i).label << "'\n" << end();
+      if (!Scenario_testing_scenario) Passed = false;
+      return false;
+    }
+  }
+  return true;
+}
+
+void test_trace_negative_check_passes_silently() {
+  Scenario_testing_scenario = true;
+  run(
+      "def main [\n"
+      "  trace-should-not-contain [\n"
+      "    a: b\n"
+      "  ]\n"
+      "]\n"
+  );
+  CHECK_TRACE_DOESNT_CONTAIN("error: unexpected [b] in trace with label 'a'");
+  CHECK_TRACE_COUNT("error", 0);
+}
+
+void test_trace_negative_check_fails_on_any_unexpected_line() {
+  Scenario_testing_scenario = true;
+  Hide_errors = true;
+  run(
+      "def main [\n"
+      "  run [\n"
+      "    trace 1, [a], [d]\n"
+      "  ]\n"
+      "  trace-should-not-contain [\n"
+      "    a: b\n"
+      "    a: d\n"
+      "  ]\n"
+      "]\n"
+  );
+  CHECK_TRACE_CONTENTS(
+      "error: F - main: unexpected [d] in trace with label 'a'\n"
+  );
+}
+
+void test_trace_count_check() {
+  run(
+      "def main [\n"
+      "  run [\n"
+      "    trace 1, [a], [foo]\n"
+      "  ]\n"
+      "  check-trace-count-for-label 1, [a]\n"
+      "]\n"
+  );
+  // checks are inside scenario
+}
+
+:(before "End Primitive Recipe Declarations")
+CHECK_TRACE_COUNT_FOR_LABEL,
+:(before "End Primitive Recipe Numbers")
+put(Recipe_ordinal, "check-trace-count-for-label", CHECK_TRACE_COUNT_FOR_LABEL);
+:(before "End Primitive Recipe Checks")
+case CHECK_TRACE_COUNT_FOR_LABEL: {
+  if (SIZE(inst.ingredients) != 2) {
+    raise << maybe(get(Recipe, r).name) << "'check-trace-count-for-label' requires exactly two ingredients, but got '" << to_original_string(inst) << "'\n" << end();
+    break;
+  }
+  if (!is_mu_number(inst.ingredients.at(0))) {
+    raise << maybe(get(Recipe, r).name) << "first ingredient of 'check-trace-count-for-label' should be a number (count), but got '" << inst.ingredients.at(0).original_string << "'\n" << end();
+    break;
+  }
+  if (!is_literal_text(inst.ingredients.at(1))) {
+    raise << maybe(get(Recipe, r).name) << "second ingredient of 'check-trace-count-for-label' should be a literal string (label), but got '" << inst.ingredients.at(1).original_string << "'\n" << end();
+    break;
+  }
+  break;
+}
+:(before "End Primitive Recipe Implementations")
+case CHECK_TRACE_COUNT_FOR_LABEL: {
+  if (!Passed) break;
+  int expected_count = ingredients.at(0).at(0);
+  string label = current_instruction().ingredients.at(1).name;
+  int count = trace_count(label);
+  if (count != expected_count) {
+    if (!Hide_errors) cerr << '\n';
+    raise << "F - " << maybe(current_recipe_name()) << "expected " << expected_count << " lines in trace with label '" << label << "' in trace\n" << end();
+    if (!Hide_errors) DUMP(label);
+    if (!Scenario_testing_scenario) Passed = false;
+  }
+  break;
+}
+
+:(before "End Primitive Recipe Declarations")
+CHECK_TRACE_COUNT_FOR_LABEL_GREATER_THAN,
+:(before "End Primitive Recipe Numbers")
+put(Recipe_ordinal, "check-trace-count-for-label-greater-than", CHECK_TRACE_COUNT_FOR_LABEL_GREATER_THAN);
+:(before "End Primitive Recipe Checks")
+case CHECK_TRACE_COUNT_FOR_LABEL_GREATER_THAN: {
+  if (SIZE(inst.ingredients) != 2) {
+    raise << maybe(get(Recipe, r).name) << "'check-trace-count-for-label' requires exactly two ingredients, but got '" << to_original_string(inst) << "'\n" << end();
+    break;
+  }
+  if (!is_mu_number(inst.ingredients.at(0))) {
+    raise << maybe(get(Recipe, r).name) << "first ingredient of 'check-trace-count-for-label' should be a number (count), but got '" << inst.ingredients.at(0).original_string << "'\n" << end();
+    break;
+  }
+  if (!is_literal_text(inst.ingredients.at(1))) {
+    raise << maybe(get(Recipe, r).name) << "second ingredient of 'check-trace-count-for-label' should be a literal string (label), but got '" << inst.ingredients.at(1).original_string << "'\n" << end();
+    break;
+  }
+  break;
+}
+:(before "End Primitive Recipe Implementations")
+case CHECK_TRACE_COUNT_FOR_LABEL_GREATER_THAN: {
+  if (!Passed) break;
+  int expected_count = ingredients.at(0).at(0);
+  string label = current_instruction().ingredients.at(1).name;
+  int count = trace_count(label);
+  if (count <= expected_count) {
+    if (!Hide_errors) cerr << '\n';
+    raise << maybe(current_recipe_name()) << "expected more than " << expected_count << " lines in trace with label '" << label << "' in trace\n" << end();
+    if (!Hide_errors) {
+      cerr << "trace contents:\n";
+      DUMP(label);
+    }
+    if (!Scenario_testing_scenario) Passed = false;
+  }
+  break;
+}
+
+:(before "End Primitive Recipe Declarations")
+CHECK_TRACE_COUNT_FOR_LABEL_LESSER_THAN,
+:(before "End Primitive Recipe Numbers")
+put(Recipe_ordinal, "check-trace-count-for-label-lesser-than", CHECK_TRACE_COUNT_FOR_LABEL_LESSER_THAN);
+:(before "End Primitive Recipe Checks")
+case CHECK_TRACE_COUNT_FOR_LABEL_LESSER_THAN: {
+  if (SIZE(inst.ingredients) != 2) {
+    raise << maybe(get(Recipe, r).name) << "'check-trace-count-for-label' requires exactly two ingredients, but got '" << to_original_string(inst) << "'\n" << end();
+    break;
+  }
+  if (!is_mu_number(inst.ingredients.at(0))) {
+    raise << maybe(get(Recipe, r).name) << "first ingredient of 'check-trace-count-for-label' should be a number (count), but got '" << inst.ingredients.at(0).original_string << "'\n" << end();
+    break;
+  }
+  if (!is_literal_text(inst.ingredients.at(1))) {
+    raise << maybe(get(Recipe, r).name) << "second ingredient of 'check-trace-count-for-label' should be a literal string (label), but got '" << inst.ingredients.at(1).original_string << "'\n" << end();
+    break;
+  }
+  break;
+}
+:(before "End Primitive Recipe Implementations")
+case CHECK_TRACE_COUNT_FOR_LABEL_LESSER_THAN: {
+  if (!Passed) break;
+  int expected_count = ingredients.at(0).at(0);
+  string label = current_instruction().ingredients.at(1).name;
+  int count = trace_count(label);
+  if (count >= expected_count) {
+    if (!Hide_errors) cerr << '\n';
+    raise << "F - " << maybe(current_recipe_name()) << "expected less than " << expected_count << " lines in trace with label '" << label << "' in trace\n" << end();
+    if (!Hide_errors) {
+      cerr << "trace contents:\n";
+      DUMP(label);
+    }
+    if (!Scenario_testing_scenario) Passed = false;
+  }
+  break;
+}
+
+:(code)
+void test_trace_count_check_2() {
+  Scenario_testing_scenario = true;
+  Hide_errors = true;
+  run(
+      "def main [\n"
+      "  run [\n"
+      "    trace 1, [a], [foo]\n"
+      "  ]\n"
+      "  check-trace-count-for-label 2, [a]\n"
+      "]\n"
+  );
+  CHECK_TRACE_CONTENTS(
+      "error: F - main: expected 2 lines in trace with label 'a' in trace\n"
+  );
+}
+
+//: Minor detail: ignore 'system' calls in scenarios, since anything we do
+//: with them is by definition impossible to test through Mu.
+:(after "case _SYSTEM:")
+  if (Current_scenario) break;
+
+//:: Warn if people use '_' manually in recipe names. They're reserved for internal use.
+
+:(code)
+void test_recipe_name_with_underscore() {
+  Hide_errors = true;
+  run(
+      "def foo_bar [\n"
+      "]\n"
+  );
+  CHECK_TRACE_CONTENTS(
+      "error: foo_bar: don't create recipes with '_' in the name\n"
+  );
+}
+
+:(before "End recipe Fields")
+bool is_autogenerated;
+:(before "End recipe Constructor")
+is_autogenerated = false;
+:(code)
+void mark_autogenerated(recipe_ordinal r) {
+  get(Recipe, r).is_autogenerated = true;
+}
+
+:(after "void transform_all()")
+  for (map<recipe_ordinal, recipe>::iterator p = Recipe.begin();  p != Recipe.end();  ++p) {
+    const recipe& r = p->second;
+    if (r.name.find('_') == string::npos) continue;
+    if (r.is_autogenerated) continue;  // created by previous call to transform_all()
+    raise << r.name << ": don't create recipes with '_' in the name\n" << end();
+  }
+
+//:: Helpers
+
+:(code)
+// just for the scenarios running scenarios in C++ layers
+void run_mu_scenario(const string& form) {
+  Scenario_names.clear();
+  istringstream in(form);
+  in >> std::noskipws;
+  skip_whitespace_and_comments(in);
+  string _scenario = next_word(in);
+  if (_scenario.empty()) {
+    assert(!has_data(in));
+    raise << "no scenario in string passed into run_mu_scenario()\n" << end();
+    return;
+  }
+  assert(_scenario == "scenario");
+  scenario s = parse_scenario(in);
+  run_mu_scenario(s);
+}