Re: [COMMITTED] pkl: add assertion to `pvm_make_array_type'

[Jose E. Marchesi]

> Hi Jose.
>
> On Fri, Oct 28, 2022 at 01:14:46AM +0200, Jose E. Marchesi wrote:
>> 
>> Hi Mohammad.
>> 
>> > diff --git a/libpoke/pvm-val.c b/libpoke/pvm-val.c
>> > index 641fbd8b..54341761 100644
>> > --- a/libpoke/pvm-val.c
>> > +++ b/libpoke/pvm-val.c
>> > @@ -527,12 +527,14 @@ pvm_make_offset_type (pvm_val base_type, pvm_val 
>> > unit)
>> >  }
>> >  
>> >  pvm_val
>> > -pvm_make_array_type (pvm_val type, pvm_val bound)
>> > +pvm_make_array_type (pvm_val type, pvm_val bounder)
>> >  {
>> >    pvm_val atype = pvm_make_type (PVM_TYPE_ARRAY);
>> >  
>> > +  assert (bounder);
>> 
>> I think this ought to be:
>> 
>>   assert (bounder != PVM_NULL);
>> 
>
> Oops!
> Sorry!
>
> And fixing it leads to a bunch of failure in `poke.pickles' and
> `poke.std' directory!

Consider this:

-------------
diff --git a/libpoke/pvm-val.c b/libpoke/pvm-val.c
index 54341761..0ce493a3 100644
--- a/libpoke/pvm-val.c
+++ b/libpoke/pvm-val.c
@@ -531,7 +531,7 @@ pvm_make_array_type (pvm_val type, pvm_val bounder)
 {
   pvm_val atype = pvm_make_type (PVM_TYPE_ARRAY);
 
-  assert (bounder);
+  assert (PVM_IS_CLS (bounder));
 
   PVM_VAL_TYP_A_ETYPE (atype) = type;
   PVM_VAL_TYP_A_BOUND (atype) = bounder;
diff --git a/poke/poke.c b/poke/poke.c
index 7b258410..6385b26a 100644
--- a/poke/poke.c
+++ b/poke/poke.c
@@ -322,6 +322,7 @@ set_script_args (int argc, char *argv[])
   int i, nargs;
   uint64_t index;
   pk_val argv_array;
+  pk_val array_type_bounder = pk_decl_val (poke_compiler, "_pkl_mkclsn");
 
   /* Look for -L SCRIPT */
   for (i = 0; i < argc; ++i)
@@ -333,7 +334,7 @@ set_script_args (int argc, char *argv[])
   nargs = argc - i;
   argv_array = pk_make_array (pk_make_uint (nargs, 64),
                               pk_make_array_type (pk_make_string_type (),
-                                                  PK_NULL /* bound */));
+                                                  array_type_bounder));
 
   for (index = 0; i < argc; ++i, ++index)
     pk_array_insert_elem (argv_array, index,
-------------

This works, but:

1) It makes use of the run-time _pkl_mkclsn, which is supposed to be an
   internal detail of the compiler run-time.  Also, it is not possible
   for libpoke users to denote PVM_NULL, so the poke app cannot define a
   bounder function that returns null, by itself.

2) pk_make_array_type in libpoke.h is documented to "at this point"
   always get PK_NULL as the `bound' argument.

We could change the documentation of pk_make_array_type to say something
like this:

  /* Build and return an array type.

     ETYPE is the type of the elements of the array.
     BOUNDER is either:
     - PVM_NULL to denote an unbounded array.
     - An uint<64> to denote an array type bounded by number of
       elements.
     - An offset<uint<64>,1> to denote an array type bounded by size.  */

Then, in libpoke.c:pk_make_array_type we can pk_decl_val and pk_call
_pkl_mkclsn/_pkl_mkclsi/_pkl_mkclso to actually create the real bounder.

This would keep things simpler for libpoke users.
For example, poke.c would remain the same as today.

WDYT?