When encoding a type to a qfo file, the type's encoding string is written
and thus needs to be valid prior to actually doing the encoding. The
problem occurs mostly in self-referential structs (particularly, obj_class)
because the struct is being encoded prior to the pointer to the struct.
This is similar to the problem with infinite recursion when encoding types.
The problem is with structs with self-referential pointers (eg, struct foo
{struct foo *bar}). The solution is to copy the type data to a buffer and
mark the buffer as transfered before actually processing the type. Further
processing of the type is done via the buffer.
As id and Class do not point to real objects as such, trying to get the
class from their types doesn't work, so instead send the message to a
"null" class that skips the method checks.
Now the classes are built "properly" (using the same tools as the parser
itself), and the structs (obj_object, obj_class and obj_protocol) are built
separately, but using the class ivars.
Even just before, type_obj_object, type_obj_class and type_obj_protocol
were a bit bogus (still are), but now the arrays used to list their ivars
are correct. I plan to create the above mentioned types using
class_to_struct to do it properly.
Type names are cleaned up, as is the creation. Also, the class pointer in
the type encoding now gets emitted. However, Still need to actually create
_OBJ_CLASS_Class and fix the type encoding reloc handling in the linker.
With the previous commit, the structures were being created before a valid
source file name was available and thus qfcc would segfault when trying to
generate a tag. Now, the tags look better anyway :).
Now, for each compilation, or before linking, only InitData needs to be
called. Fixes the double chaining internal error when compiling and linking
in the same command.
This required throwing out the primary rules that snax did up to help me
with conflicts many years ago, but they were now getting in the way. Now
the productions from primary are merged in with unary_expr.
It turns out no code was being generated for x = *y. Ouch. I suspect I need
to take a better look at expr_deref at some time in the not too distant
future.
Conflicts:
tools/qfcc/source/statements.c
The base of the type encodings block is given by the .type_encodings def.
The block begins with a "null" type (4 words of 0), followed by the first
type encoding.
At some stage, I will need to add information for extended def information
(32 bit offset, type encoding, other?), but this is good for initial
testing.
Structures (especially hard-coded ones) can be really nasty as they can
refer to themselves. Avoid the recursion by setting the type_def field of
the type before doing the recursive encodings in the structure encoder.
The encodings of static types were getting corrupted because their defs
were not necessarily in the same places between compilations when compiling
multiple files.
The result of parse_params needs to be passed through find_type before
actually being used. I guess I'd missed this back when I got things working
for qc.
Since gnu bison and flex are required anyway, no harm in using their api
prefix options. Now, qfcc can compile both QC/Ruamoko and Pascal files
(Pascal is (currently?) NOT supported in progs.src mode), selecting the
language based on the extension: .r, .qc and .c select QC/Ruamoko, .pas and
.p select Pascal, while anything else is treated as an object file (as
before).
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. :)
