[bitc-dev] A few bugs

[Swaroop Sridhar]

Aleksi Nurmi wrote:
> I was searching the Web for system programming languages, found BitC
> and decided to rsync it out. However, I encountered a few bugs and
> investigated them a little. I couldn't find a bug tracker, so I
> thought I'd post my findings here. For the record, I'm running the
> AMD64 version of Ubuntu Linux.

Aleksi: Thanks for pointing out the bugs. I have tried to address these
issues in my latest commit.

> 1. This is the most obvious one: lib64/libbitc.bita is missing
> whitespace after import statements, resulting in lines such as
> "(importbitc.stdio as stdio)".

Fixed this bug. Thanks for the patch too. I did not really apply it
since the change was very small, but it is the same solution.

> 2. Reading a character from standard input often segfaults. The cause
> is libbitc/stdio.c and a null/uninitialized pointer. Placing
> assert(ios->f) right after fix_stdio_stream(ios) _sometimes_ catches a
> null pointer. This is pretty strange, because

I was unable to reproduce this bug. How are you running it?

I ran the same program (called h2.bitc below)
> (bitc-version "0.10")
> (import bitc.main as main)
> (provide bitc.main main)
> (import bitc.stdio as stdio)
> 
> (define main.main:(fn (vector string) -> int32)
>     (lambda (argvec)
>     (stdio.read-char stdio.stdin)
>     (stdio.write-string stdio.stdout "hello")
>     (stdio.write-char stdio.stdout #\linefeed)
>     0))

and it runs fine:
[swaroop at rice compiler]$ BUILD/bitcc --nostdlib -I ../libbitc/ -o h2 
h2.bitc ../libbitc/BUILD/libbitc.a
[swaroop at rice compiler]$ ./h2
a
hello

> 3. This is not a bug per se, but rather an usability nitpick. I had to
> read the source to find out how to make bitcc find its libraries from
> a nonstandard --prefix location and to output C code.

I added a extra line (--emit 'Language') to the bitc --help output that
shows how to specify the output language. About the library issue, are
you talking about the --system option?

Swaroop.