Add C backend - close #4

spec/testutils.c

@@ -0,0 +1,38 @@
+#include <stdio.h>
+#include <assert.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include "testutils.h"
+
+void assert_eq_size_t_i(size_t expected, size_t actual, char const * file, size_t line)
+{
+    if (expected != actual)
+    {
+        fprintf(stderr, "%s:%lu: expected %lu, got %lu\n", file, line, expected, actual);
+        assert(false);
+    }
+}
+
+void str_init(str_t * str, char const * cs)
+{
+    size_t length = strlen(cs);
+    str->cs = malloc(length + 1u);
+    strcpy(str->cs, cs);
+}
+
+void str_append(str_t * str, char const * cs)
+{
+    size_t length = strlen(str->cs);
+    size_t length2 = strlen(cs);
+    char * new_cs = malloc(length + length2 + 1u);
+    memcpy(new_cs, str->cs, length);
+    strcpy(&new_cs[length], cs);
+    free(str->cs);
+    str->cs = new_cs;
+}
+
+void str_free(str_t * str)
+{
+    free(str->cs);
+}