Introduce a check() method (like assert() but always on)

kernel/CMakeLists.txt

@@ -27,6 +27,8 @@ add_executable(moon ${SOURCES})
 
 target_link_libraries(moon moon-asm)
 
+target_compile_definitions(moon PRIVATE IN_MOON)
+
 target_compile_options(moon PRIVATE -Os)
 
 target_compile_options(moon PRIVATE -pedantic -Wall -Wextra -Werror -Wvla)

kernel/src/main.cpp

@@ -84,5 +84,7 @@ extern "C" [[noreturn]] void _start()
 
     Serial::println("Successfully unmapped address");
 
+    check(false);
+
     CPU::efficient_halt();
 }

luna/Check.h

@@ -0,0 +1,22 @@
+#pragma once
+#ifdef IN_MOON
+#include "arch/Serial.h"
+
+[[noreturn]] inline bool __check_failed(const char* string)
+{
+    Serial::print("CHECK FAILED: ");
+    Serial::println(string);
+    for (;;)
+        ;
+}
+#else
+[[noreturn]] inline bool __check_failed(const char*)
+{
+    __builtin_trap();
+}
+#endif
+
+#define STRINGIZE(x) #x
+#define STRINGIZE_VALUE_OF(x) STRINGIZE(x)
+
+#define check(expr) (expr) || __check_failed("at " __FILE__ ":" STRINGIZE_VALUE_OF(__LINE__) ": " #expr)

luna/Result.h

@@ -1,4 +1,5 @@
 #pragma once
+#include <Check.h>
 #include <Move.h>
 #include <PlacementNew.h>
 #include <Types.h>
@@ -81,19 +82,19 @@ template <typename T> class Result
 
     int error()
     {
-        // ensure(has_error());
+        check(has_error());
         return m_error;
     }
 
     Error release_error()
     {
-        // ensure(has_error());
+        check(has_error());
         return {m_error};
     }
 
     T value()
     {
-        // ensure(has_value());
+        check(has_value());
         return m_storage.fetch_reference();
     }
 
@@ -105,7 +106,7 @@ template <typename T> class Result
 
     T release_value()
     {
-        // ensure(has_value());
+        check(has_value());
         T item = m_storage.fetch_reference();
         m_has_value = false;
         m_storage.destroy();
@@ -206,25 +207,25 @@ template <> class Result<void>
 
     int error()
     {
-        // ensure(has_error());
+        check(has_error());
         return m_error;
     }
 
     Error release_error()
     {
-        // ensure(has_error());
+        check(has_error());
         return {m_error};
     }
 
     void value()
     {
-        // ensure(has_value());
+        check(has_value());
         return;
     }
 
     void release_value()
     {
-        // ensure(has_value());
+        check(has_value());
         return;
     }