Because type aliases need to be unaliased, the type pointers in the type
encodings need to be correct when it comes to linking defs and
functions. This fixes the linking errors in ruamoko/game.
I was very uncertain about the validity of messing with the old type
encoding that way, but adding the check to ensure the type has been
processed never fired, so it seems ok. And the comments help me a lot :)
When aliasing a type that already has aliases, the top node needs to be
replaced if it is unnamed, or the alias-free branch of the new node
needs to reach around to the alias-free branch of the existing node.
This fixes the bogus param counts in qwaq.
This fixes the typelinker test, but not the linking error in
ruamoko/game that it was supposed to represent. I guess there's
something more going on (maybe type encoding relocation issues).
Fixes#6
It turned out that the problem with @zero was caused by initial type
chaining occurring before the structures had been initialized and thus
the linker's @zero type encoding string was incorrect: {?=} instead of
{tag @zero-}, thus when the actual type encoding supplied by an object
file came along (with the correct encoding string), it wasn't found.
It is now "consistent" with the rest of the type building in that it
uses find_type(append_type(return, params)) like the C version, thus
allowing append_type to do its thing with type aliases. This fixes the
overload test.
The full_type branch of an alias splitter (alias with null name) needs
to mirror the clean side up to the type alias. It is causing problems
with functions, but that's expected because parameters complicate
things.
It's not connected up yet because I'm unsure of just where to put things
(it gets messy fast), but just being able to see the structure of
complex types is nice.
This eases type unaliasing on functions a little.
Still more to to go, but this fixes a really hair-pulling bug: linux's
heap randomiser was making the typedef test fail randomly whenever
typedef.qfo was compiled.
When a type is aliased, the alias has two type chains: the simple type
chain with all other aliases stripped, and the full type chain. There
are still plenty of bugs in it, but having the clean type chain takes
care of the major issue that was in the previous attempt as only the
head of the type-chain needs to be skipped for type comparison.
Most of the bugs are in finding the locations where the head needs to be
skipped.
All simple type checks are now done using is_* helper functions. This
will help hide the implementation details of the type system from the
rest of the compiler (especially the changes needed for type aliasing).
They take a pointer to a free-list used for hashlinks so the hashlink
pools can be per-thread. However, hash tables that are not updated are
always thread-safe, so this affects only updates. progs_t has been set
up such that it is easy for multiple progs within one thread can share
hashlinks.
and its usage. The parts of flow_analyze_statement that use it know
where the returned operand needs to go. Unfortunately, this breaks dags
pretty hard, but that's because dags needs to learn about the fancy
assignment-type statements.
