Start adding tests

test/tests.cpp

@@ -1,14 +1,115 @@
 #include <catch2/catch.hpp>
 
-unsigned int Factorial(unsigned int number)
+#include <fmt/format.h>
+#include <fstream>
+
+enum struct OptimizationLevel : char { O0='0', O1='1', O2='2', O3='3', Os='s' };
+
+
+std::vector<std::uint8_t> execute_c64_program(const std::string_view &name,
+  const std::string_view script,
+  [[maybe_unused]] OptimizationLevel o,
+  std::uint16_t start_address_dump,
+  std::uint16_t end_address_dump)
 {
-  return number <= 1 ? number : Factorial(number - 1) * number;
+
+  const char *x64_executable = std::getenv("X64");
+  REQUIRE(x64_executable != nullptr);
+  const char *mos6502_cpp_executable = std::getenv("CXX_6502");
+  REQUIRE(mos6502_cpp_executable != nullptr);
+
+  const auto optimization_level = [&]() -> std::string_view {
+    switch(o) {
+    case OptimizationLevel::Os: return "-Os";
+    case OptimizationLevel::O1: return "-O1";
+    case OptimizationLevel::O2: return "-O2";
+    case OptimizationLevel::O3: return "-O3";
+    case OptimizationLevel::O0: return "-O0";
+    }
+
+    return "unknown";
+  }();
+  const auto source_filename{ fmt::format("{}{}.cpp", name, optimization_level) };
+  const auto vice_script_filename{fmt::format("{}{}-vice_script", name, optimization_level)};
+  const auto prg_filename{ fmt::format("{}{}.prg", name, optimization_level) };
+  const auto ram_dump_filename{ fmt::format("{}{}-ram_dump", name, optimization_level) };
+
+
+  {
+    std::ofstream source(source_filename);
+    source << script;
+  }
+
+  {
+    std::ofstream vice_script(vice_script_filename);
+    vice_script << fmt::format(
+      R"(
+z 100000
+l "{}" 0
+keybuf run\n
+z 100000
+bsave "{}" 0 {:x} {:x}
+quit
+)",
+      prg_filename,
+      ram_dump_filename,
+      start_address_dump,
+      end_address_dump);
+  }
+
+
+  REQUIRE(system(fmt::format("{} -f {} -t C64 {}", mos6502_cpp_executable, source_filename, optimization_level).c_str()) == EXIT_SUCCESS);
+  REQUIRE(system(fmt::format("xvfb-run {} +saveres -warp -moncommands {}", x64_executable, vice_script_filename).c_str()) == EXIT_SUCCESS);
+
+  std::ifstream memory_dump(ram_dump_filename, std::ios::binary);
+
+  std::vector<char> data;
+  data.resize(static_cast<std::size_t>(end_address_dump - start_address_dump + 1));
+  memory_dump.read(data.data(), std::ssize(data));
+
+  std::vector<std::uint8_t> return_value{ data.begin(), data.end() };
+  return return_value;
 }
 
-TEST_CASE("Factorials are computed", "[factorial]")
+TEST_CASE("Can write to screen memory")
 {
-  REQUIRE(Factorial(1) == 1);
-  REQUIRE(Factorial(2) == 2);
-  REQUIRE(Factorial(3) == 6);
-  REQUIRE(Factorial(10) == 3628800);
+  constexpr static std::string_view program =
+    R"(
+int main()
+{
+  *reinterpret_cast<volatile unsigned char *>(0x400) = 10;
+}
+)";
+
+  const auto o_level = GENERATE(OptimizationLevel::O0, OptimizationLevel::O1, OptimizationLevel::O2, OptimizationLevel::O3, OptimizationLevel::Os);
+  const auto result = execute_c64_program("write_to_screen_memory", program, o_level, 0x400, 0x400);
+
+  REQUIRE(result.size() == 1);
+  CHECK(result[0] == 10);
+}
+
+TEST_CASE("Can write to screen memory via function call")
+{
+  constexpr static std::string_view program =
+    R"(
+
+void poke(unsigned int location, unsigned char value) {
+  *reinterpret_cast<volatile unsigned char *>(location) = 10;
+}
+
+int main()
+{
+  poke(0x400, 10);
+  poke(0x401, 11);
+}
+)";
+
+  const auto o_level = GENERATE(
+    OptimizationLevel::O0, OptimizationLevel::O1, OptimizationLevel::O2, OptimizationLevel::O3, OptimizationLevel::Os);
+  const auto result = execute_c64_program("write_to_screen_memory_via_function", program, o_level, 0x400, 0x401);
+
+  REQUIRE(result.size() == 2);
+  CHECK(result[0] == 10);
+  CHECK(result[0] == 11);
+
 }