implement / re-implement error-handling

.vscode/launch.json

@@ -5,6 +5,9 @@
             "name": "(lldb) debug project",
             "type": "lldb",
             "request": "launch",
+            "env": {
+                "DEBUG": "1"
+            },
             "program": "",
             "linux": {
                 "preLaunchTask": "(dbg) compile linux-x86_64",

src/error_handling.c

@@ -0,0 +1,54 @@
+#include "error_handling.h"
+
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "SDL_messagebox.h"
+#include "main.h"
+
+#define PRINT_BUFFER_SIZE 128 // defines the buffer size for printing
+
+// writes the arguments to the specified buffer
+#define write_args(buf, fmt)                            \
+    va_list args;                                       \
+    va_start(args, fmt);                                \
+    (void)vsnprintf(buf, PRINT_BUFFER_SIZE, fmt, args); \
+    va_end(args);
+
+// sets the game status (in turn exiting (if not set to STATUS_RUNNING))
+static void stop(gamestatus status) {
+    set_gamestatus(status);
+}
+
+void debug(char const* fmt, ...) {
+    char const* env = getenv("DEBUG");
+    if (env == NULL || *env != '1')
+        return;
+
+    char buf[PRINT_BUFFER_SIZE] = {0};
+    write_args(buf, fmt);
+
+    (void)fprintf(stdout, "\033[95m%s\033[0m\n", buf);
+}
+
+void info(char const* fmt, ...) {
+    char buf[PRINT_BUFFER_SIZE] = {0};
+    write_args(buf, fmt);
+    (void)fprintf(stdout, "\033[0m%s\033[0m\n", buf); // write colour here for consistency
+}
+
+void warn(char const* fmt, ...) {
+    char buf[PRINT_BUFFER_SIZE] = {0};
+    write_args(buf, fmt);
+    (void)fprintf(stderr, "\033[93mW: %s\033[0m\n", buf);
+}
+
+void error(gamestatus status, char const* fmt, ...) {
+    char buf[PRINT_BUFFER_SIZE] = {0};
+    write_args(buf, fmt);
+    (void)fprintf(stderr, "\033[91mE: %s\033[0m\n", buf);
+    SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR, "something went wrong! :O", buf, NULL);
+    stop(status);
+}

src/error_handling.h

@@ -0,0 +1,33 @@
+#pragma once
+
+#include <stdint.h>
+
+/* defines statuses in the 0..127, any higher/negative values are POSIX-reserved.
+ * The max value (or -1) shall mean the application is running, anything else shall mean an exit code of some kind */
+enum {
+    // clang-format off
+    STATUS_SUCCESS = 0,                // 0; successful exit
+    STATUS_ERROR   = 1,                // miscellaneous error
+    ERROR_INIT     = STATUS_ERROR | 2, // initialisation error
+
+    ERROR_STD             = STATUS_ERROR   | 64, // standard library error
+    ERROR_STD_INIT        = ERROR_INIT     | 64, // standard library initialisation error
+    ERROR_STD_MEMORY      = ERROR_STD      | 32, // memory error
+    ERROR_STD_MEMORY_INIT = ERROR_STD_INIT | 32, // memory initialization error
+
+    ERROR_SDL                = STATUS_ERROR   | 32, // SDL error
+    ERROR_SDL_INIT           = ERROR_INIT     | 32, // SDL initialization error
+    ERROR_SDL_RENDERING      = ERROR_SDL      | 16, // rendering error
+    ERROR_SDL_RENDERING_INIT = ERROR_SDL_INIT | 16, // rendering initialization error
+    ERROR_SDL_AUDIO          = ERROR_SDL      | 8,  // audio error
+    ERROR_SDL_AUDIO_INIT     = ERROR_SDL_INIT | 8,  // audio initialization error
+
+    STATUS_RUNNING = -1,
+    // clang-format on
+};
+typedef int8_t gamestatus;
+
+void debug(char const*, ...);             // prints a debug message to stdout if the DEBUG environment variable is set, otherwise the call is ignored.
+void info(char const*, ...);              // prints an info message to stdout
+void warn(char const*, ...);              // prints a warning message to stderr
+void error(gamestatus, char const*, ...); // prints an error message to stderr

src/main.c

@@ -1,8 +1,17 @@
+#include "main.h"
+
 #include <stdint.h>
-#include <stdio.h>
+
+#include "error_handling.h"
+
+static gamestatus status = STATUS_RUNNING;
+
+void set_gamestatus(gamestatus new_status) {
+    status = new_status;
+}
 
 int32_t main(int32_t argc, char** argv) {
     (void)argc, (void)argv;
-    printf("%s\n", "Hello, World!");
+    debug("%s", "Hello, World!");
-    return 0;
+    return status;
 }

src/main.h

@@ -0,0 +1,5 @@
+#pragma once
+
+#include "error_handling.h"
+
+void set_gamestatus(gamestatus); // sets the status of the game (allows for quitting the game)