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).
That is, those created by operand_address. The dag code needs the
expression that is attached to the statement to have the correct
expression type in order to do the right thing with the operands and
aliasing, especially when generating temps. This fixes assignchain when
optimizing (all tests pass again).
Now convert_nil only assigns the nil expression a type, and nil makes
its way down to the statement emission code (where it belongs, really).
Breaks even more things :)
It's not possible to take the address of constants (at this stage) and
trying to use a move instruction with .zero as source would result in
the VM complaining about null pointer access when bounds checking is on.
Thus, don't convert a nil source expression until it is known to be
safe, and use memset when it is not.
This fixes the problem of using the return value of a function as an
element in a compound initializer. The cause of the problem is that
compound initializers were represented by block expressions, but
function calls are contained within block expressions, so def
initialization saw the block expression and thought it was a nested
compound initializer.
Technically, it was a bug in the nested element parsing code in that it
wasn't checking the result value of the block expression, but using a
whole new expression type makes things much cleaner and the work done
paves the way for labeled initializers and compound assignments.
Multi-line calls (especially messages) got rather confusing to read as
the lines jumped back and forth. Now the binding is better but the dags
code is reordering the parameters sometimes.
This reverts commit a2f203c840.
There is indeed a world of difference between "any" and "only", and it
helps if I read the rest of the docs AND the code :P.
While expression symbols worked for what they are, they weren't so good
for ivar access because every ivar of a class (and its super classes)
would be accessed at method scope creation, generating spurious access
errors if any were private. That is, when the access checks worked at
all.
