Return statements never flow to the next block (or any other block, for
that matter), so drawing arrows leaving them not only messes up dot's
graphs, but is quite missleading.
When mering if/goto (ie, if skipping a goto), the rest of the dead code
remover is used to delete the goto. That part of the code unuses the goto's
label. The if was getting the goto's label without the lable's used count
being incremented (the usaged temporarily increases by one). I have no idea
why the problem showed up randomly, but this seems to fix it (it fixes /a/
bug, anyway).
The naive implementation of the if/goto merging was letting the old target
of the if get dropped because the block would lose its label and thus be
judged unreachable because the preceeding goto block was still in the list.
Instead, when the if/goto are "merged", mark the goto block as unreachable,
the following block as reachable, and break out of the analysis loop to
force the removal of the goto block. Since the dead block removal function
loops until no action is taken, all other dead blocks will be removed.
The output can be controlled via --block-dot (not yet documented). The
files a named <sourcefile>.<function>.<stage>.dot. Currently, stage will be
one of "initial" (after expression to statement conversion), "thread"
(after jump threading), "dead" (after dead block removal), "final" (final
state before actual code emission).
Labels can be shared between multiple flow-control instructions, so use the
label's used counter to determine when to remove the label. This was
causing problems with the jump threading.
The common cause seems to be casting a cast (very common, and I'm not sure
just realiasing the expression would be right). It does't cause any harm
(particularly, it doesn't trigger alias def chains), so I won't worry about
it.
The actual bug might still be elsewhere, but at least now I know the alias
chains were coming from accessing .return and .param_N, which are unions
(not directly usable by the progs engine). Emitting a reference to a union
(or struct) would create an alias def, but an alias expression was created
in the expression tree to simplify return/param access. The double layer
(sometimes 3 or 4) alias isn't really neaded, so rather than layering the
aliases, just re-alias the alaised def.
It is inteded for flagging buggy conditions in the compiler, particularly
after having fixed the original bug (in case something comes back from the
dead).
v6 progs expects .zero to be only 1 word. The code actually tried to keep
vector out of .zero, but it seems I'd rearranged the structure defintion
without updating the code that kills the vector field. Problem spotted by
divVerent.
Despair has things locked down such that running qfcc during a build fails
due to lack of read access to /usr/local/lib. This is actually a good
thing as accidentally hitting old includes/libs (when a file gets deleted
in the tree) hides bugs. Thus, --no-default-paths to turn off default
search paths.
The special token __INFINITY__, like __FILE__ and friends, will expand to
a floating-point expression containing a value the C compiler considers
infinite. Obviously, this assumes that the system has relatively modern
float hardware -- but if it doesn't, having Ruamoko be able to represent
float infinity is the least of your problems. :)
Initializing a field variable to another field will set the new field to
point to the same location. No type checking is done.
eg:
.SEL thinkMethod = think;
Statement operands throw away the high level type information, so store
type size in the operand and use this size for allocating space for temps
rather than using the low-level type.
Although vector and quaternion types have symbol tables, they are not
really structs, so set the meta type to "none", allowing the types to be
encoded correctly.
Freeing then re-allocating a def to change its storage from external is
really not the right way to do it, but for now this fixes the loss of the
relocs. With this, the menus seem to work :)
Look in the entity field symbol table for the field before looking in the
normal symbol table. This allows entity fields to be accessed even when
the current scope has symbol of the same name. However, checking the
normal symbol table where there is no such field allows for field
variables when I get around to implementing them.
