1 files changed, 95 insertions, 0 deletions
diff --git a/linux/bootstrap/040tests.cc b/linux/bootstrap/040tests.cc
new file mode 100644
index 00000000..0586249b
--- /dev/null
+++ b/linux/bootstrap/040tests.cc
@@ -0,0 +1,95 @@
+//: Automatically aggregate functions starting with 'test-' into a test suite
+//: called 'run-tests'. Running this function will run all tests.
+//:
+//: This is actually SubX's first (trivial) compiler. We generate all the code
+//: needed for the 'run-tests' function.
+//:
+//: By convention, temporary functions needed by tests will start with
+//: '_test-'.
+
+//: We don't rely on any transforms running in previous layers, but this layer
+//: knows about labels and will emit labels for previous layers to transform.
+:(after "Begin Transforms")
+Transform.push_back(create_test_function);
+
+:(code)
+void test_run_test() {
+  Mem.push_back(vma(0xbd000000));  // manually allocate memory
+  Reg[ESP].u = 0xbd000100;
+  run(
+      "== code 0x1\n"  // code segment
+      "main:\n"
+      "  e8/call run-tests/disp32\n"  // 5 bytes
+      "  f4/halt\n"                   // 1 byte
+      "test-foo:\n"  // offset 7
+      "  01 d8\n"  // just some unique instruction: add EBX to EAX
+      "  c3/return\n"
+  );
+  // check that code in test-foo ran (implicitly called by run-tests)
+  CHECK_TRACE_CONTENTS(
+      "run: 0x00000007 opcode: 01\n"
+  );
+}
+
+void create_test_function(program& p) {
+  if (p.segments.empty()) return;
+  segment& code = *find(p, "code");
+  trace(3, "transform") << "-- create 'run-tests'" << end();
+  vector<line> new_insts;
+  for (int i = 0;  i < SIZE(code.lines);  ++i) {
+    line& inst = code.lines.at(i);
+    for (int j = 0;  j < SIZE(inst.words);  ++j) {
+      const word& curr = inst.words.at(j);
+      if (*curr.data.rbegin() != ':') continue;  // not a label
+      if (!starts_with(curr.data, "test-")) continue;
+      string fn = drop_last(curr.data);
+      new_insts.push_back(call(fn));
+    }
+  }
+  if (new_insts.empty()) return;  // no tests found
+  code.lines.push_back(label("run-tests"));
+  code.lines.insert(code.lines.end(), new_insts.begin(), new_insts.end());
+  code.lines.push_back(ret());
+}
+
+string to_string(const segment& s) {
+  ostringstream out;
+  for (int i = 0;  i < SIZE(s.lines);  ++i) {
+    const line& l = s.lines.at(i);
+    for (int j = 0;  j < SIZE(l.words);  ++j) {
+      if (j > 0) out << ' ';
+      out << to_string(l.words.at(j));
+    }
+    out << '\n';
+  }
+  return out.str();
+}
+
+line call(string s) {
+  line result;
+  result.words.push_back(call());
+  result.words.push_back(disp32(s));
+  return result;
+}
+
+word call() {
+  word result;
+  result.data = "e8";
+  result.metadata.push_back("call");
+  return result;
+}
+
+word disp32(string s) {
+  word result;
+  result.data = s;
+  result.metadata.push_back("disp32");
+  return result;
+}
+
+line ret() {
+  line result;
+  result.words.push_back(word());
+  result.words.back().data = "c3";
+  result.words.back().metadata.push_back("return");
+  return result;
+}