__FILE__ crash

[felixjones]

Following causes a crash:

mrb_state * mrb = mrb_open();
mrb_load_string( mrb, "__FILE__" );

enable_debug prints:

mrb_debug_info_append_file: assertion "irep->filename" failed

The culprit is the strlen check here:
https://github.com/mruby/mruby/blob/master/src/debug.c#L157

It is my understanding that strlen( NULL ) is undefined behaviour. I expect there are platforms that will return 0 for this case and thus silently continue.

Removing the assert and changing 157 to check for NULL fixes the crash:

// mrb_assert(irep->filename);
fn_len = irep->filename ? strlen(irep->filename) : 0;

I don't consider this a solution as it results in __FILE__ printing as (null), rather than anything meaningful.

In the case of __FILE__ without a file-name, what is the expected output? Is there a mechanism for defining the value for __FILE__?

[felixjones]

From inspection of

mruby/mrbgems/mruby-compiler/core/parse.y

Line 2940 in cd0ac59

p->filename = "(null)";

It looks like the expected output should be "(null)", but this is failing at some point.