Unions allow multiple memory allocations (using ds, etc.) to share the
same space in memory.
This allows games to use the same memory for different purposes,
depending on their state.
This also adds documentation on how to use the new UNION, NEXTU, and
ENDU keywords.
In addition, make some formatting changes, and add some extra error handling (for when ELIF, ELSE, or ENDC are encountered without a corresponding IF).
Local symbols can now be referenced outside the scope of their parent, by using the syntax “Parent.Chlid”.
- Local symbol names are now stored internally as “Parent.Child”.
- The symbol’s scope field no longer forms a linked list of the prior local symbols; it will now always contain the parent.
- Add the ability use EXPORT and GLOBAL with local symbols.
- Reduce duplication between findsymbol() and findpsymbol(), as well as between sym_AddLocalReloc() and sym_AddReloc().
They work with the 16-bit registers BC, DE and HL, returning the
corresponding 8-bit register. HIGH() works with AF as well, returning A.
They also work with any kind of constant or symbol, generating a RPN
patch in the object file if the value is not defined at assembly time.
They work with macro arguments as well.
Signed-off-by: Antonio Niño Díaz <antonio_nd@outlook.com>
If a macro arg came in the middle of a symbol or at the end, e.g. "SYM\1", it would say that the symbol was not defined. This was because it wasn't looking up the macro arg's value correctly.
A reference to an invalid macro argument (\ not followed by a digit
between 1 and 9) will cause an access outside of the bounds of the
currentmacroargs array in sym_FindMacroArg().
Macro arg references are processed in two places:
In CopyMacroArg(): called when scanning tokens between "", {} and
arguments of a macro call. The only problem here is that it accepts \0
as valid and so calls sym_FindMacroArg with a invalid value.
In PutMacroArg(): called by the lexer automata when it encounters a
token matching \\[0-9]? (in other cases than above). So not only it
accepts \0 but also \ alone.
Memo: In setuplex(), a rule is defined with a regex composed of up to
three ranges of chars and takes the form:
[FirstRange]
or [FirstRange][SecondRange]?
or [FirstRange]([SecondRange][Range]*)?
On scanning, when several rules match, the first longuest one is
choosen.
Regression test:
1)
SECTION "HOME", HOME
db "\0"
2)
SECTION "HOME", HOME
db \A
3)
SECTION "HOME", HOME
db \
The problem occurs when \@ is accessed outside the definition of a
macro and is not between "" or {}, or when it is used in an argument of
a macro call, i.e. when the access is processed by PutUniqueArg().
PutUniqueArg(), puts back the string value of \@ to the lexer's buffer
(to substitute \@ by the unique label string).
When \@ is not defined, sym_FindMacroArg(-1) returns NULL, which
yyunputstr() doesn't expect and crashes.
Solution:
Generate an error when \@ is not defined.
Regression test:
SECTION "HOME", HOME
ld a,\@
Will segfault.
On the fixed version, it will return an error as \@ is not available.
Merging lai's source with this one is very irritating because
they have different indentation styles. I couldn't find what profile
vegard used for his version, so I used these flags (which should bring
the source close to KNF):
-bap
-br
-ce
-ci4
-cli0
-d0
-di0
-i8
-ip
-l79
-nbc
-ncdb
-ndj
-ei
-nfc1
-nlp
-npcs
-psl
-sc
-sob
