[Ur] Collecting Ur/Web examples

[Adam Chlipala]

Thanks for the patch!  I think your change below isn't enough to avoid 
all allocation of non-word-aligned addresses for uses that may require 
word alignment.  In particular, the patch only changes the code that 
runs during process initialization.  I've pushed a derived patch that 
covers a few more cases, and we can hunt down any that remain on demand, 
as folks stumble across them in testing. ;)

On 05/07/2014 11:52 PM, Evan Danaher wrote:
> diff -purN urweb-20131231/src/c/urweb.c urweb-20131231-mine/src/c/urweb.c
> --- urweb-20131231/src/c/urweb.c  2013-12-31 07:49:04.000000000 -0800
> +++ urweb-20131231-mine/src/c/urweb.c 2014-03-26 15:21:42.121568001 -0700
> @@ -1257,12 +1257,13 @@ void *uw_malloc(uw_context ctx, size_t l
>     void *result;
>
>     if (ctx->amInitializing) {
> -    result = malloc(len);
> +    int error = posix_memalign(&result, 4, len);
> +    //result = malloc(len);
>
> -    if (result)
> +    if (!error)
>         return result;
>       else
> -      uw_error(ctx, FATAL, "uw_malloc: malloc() returns 0");
> +      uw_error(ctx, FATAL, "uw_malloc: posix_memalign() returns %d", error);
>     } else {
>       uw_check_heap(ctx, len);