Add error type and some default error values

src/common/error.c

@@ -0,0 +1,53 @@
+#include "error.h"
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+error_t *const err_errorf_alloc =
+    &(error_t){.message = "Allocation failed during formatting of another error"};
+
+error_t *const err_errorf_length = &(error_t){
+    .message = "Formatting of another error failed to determine the error length"};
+
+error_t *const err_eof = &(error_t){.message = "Read failed because EOF is reached"};
+
+error_t *const err_unknown_read_failure = &(error_t){.message = "Unknown read error"};
+
+error_t *const err_allocation_failed = &(error_t){.message = "Memory allocation failed"};
+
+error_t *const err_integer_overflow = &(error_t){.message = "Integer overflow"};
+
+error_t *const err_invalid_parameters =
+    &(error_t){.message = "One or more parameters were invalid"};
+
+error_t *errorf(const char *fmt, ...) {
+    error_t *err = calloc(1, sizeof(error_t));
+    if (err == nullptr)
+        return err_errorf_alloc;
+
+    va_list args;
+    va_list args_count;
+    va_start(args, fmt);
+    va_copy(args_count, args);
+
+    int size = vsnprintf(nullptr, 0, fmt, args_count) + 1;
+    va_end(args_count);
+    if (size <= 0) {
+        free(err);
+        va_end(args);
+        return err_errorf_length;
+    }
+
+    err->message = malloc(size);
+    if (err->message == nullptr) {
+        free(err);
+        va_end(args);
+        return err_errorf_alloc;
+    }
+
+    vsnprintf(err->message, size, fmt, args);
+    va_end(args);
+    err->is_heap_allocated = true;
+    return err;
+}

src/common/error.h

@@ -0,0 +1,28 @@
+#ifndef INCLUDE_COMMON_ERROR_H_
+#define INCLUDE_COMMON_ERROR_H_
+
+#include <stdlib.h>
+
+typedef struct error {
+    char *message;
+    bool is_heap_allocated;
+} error_t;
+
+error_t *errorf(const char *fmt, ...);
+static inline void error_free(error_t *err) {
+    if (err == nullptr)
+        return;
+    if (!err->is_heap_allocated)
+        return;
+    free(err->message);
+    free(err);
+}
+
+/* Some global errors */
+extern error_t *const err_allocation_failed;
+extern error_t *const err_integer_overflow;
+extern error_t *const err_invalid_parameters;
+extern error_t *const err_eof;
+extern error_t *const err_unknown_read_failure;
+
+#endif // INCLUDE_COMMON_ERROR_H_