linters, some ast headers

zig1.c

@@ -6,11 +6,16 @@
 // - code = 0: program successfully terminated.
 // - code = 1: panicked, panic message in msg. Caller should free msg.
 // - code = 2: interpreter error, error in msg. Caller should free msg.
-int zig1_run(char* program, char** msg) { return 0; }
+int zig1_run(const char* program, char** msg)
+{
+    (void)program;
+    (void)msg;
+    return 0;
+}
 
 // API: run and:
 // code = 3: abnormal error, expect something in stderr.
-int zig1_run_file(char* fname, char** msg)
+int zig1_run_file(const char* fname, char** msg)
 {
     FILE* f = fopen(fname, "r");
     if (f == NULL) {
@@ -18,12 +23,13 @@ int zig1_run_file(char* fname, char** msg)
         return 3;
     }
     fseek(f, 0, SEEK_END);
-    long fsize = ftell(f);
-    if (fsize == -1) {
+    long fsizel = ftell(f);
+    if (fsizel == -1) {
         perror("ftell");
         fclose(f);
         return 3;
     }
+    unsigned long fsize = (unsigned long)fsizel;
     fseek(f, 0, SEEK_SET);
 
     char* program = malloc(fsize + 1);