This began with a change to support "BRK <operand>" in cc65. The
assembler only supports this for 65816 projects, so we detect that
and enable it when available.
While fiddling with some test code an assertion fired. This
revealed a minor issue in the code analyzer: when overwriting inline
data with instructions, we weren't resetting the format descriptor.
The code that exercises it, which requires two-byte BRKs and an
inline BRK handler in an extension script, has been added to test
2022-extension-scripts.
The new regression test revealed a flaw in the 64tass code
generator's character encoding scanner that caused it to hang.
Fixed.
Sometimes there's a bunch of junk in the binary that isn't used for
anything. Often it's there to make things line up at the start of
a page boundary.
This adds a ".junk" directive that tells the disassembler that it
can safely disregard the contents of a region. If the region ends
on a power-of-two boundary, an alignment value can be specified.
The assembly source generators will output an alignment directive
when possible, a .fill directive when appropriate, and a .dense
directive when all else fails. Because we're required to regenerate
the original data file, it's not always possible to avoid generating
a hex dump.
In a recent survey, three out of four cross assemblers surveyed
recommended not using opcode mnemonics to their patients who use
labels. We now remap labels like "AND" and "jmp", using the label
map that's part of the label localizer.
We skip the step for Merlin 32, which is perfectly happy to assemble
"JMP JMP JMP".
Also, fixed a bug in MaskLeadingUnderscores that could hang the
source generator thread.
Most assemblers end local label scope when a global label is
encountered. cc65 takes this one step further by ending local label
scope when constants or variables are defined. So, if we have a
variable table with a nonzero number of entries, we want to create
a fake global label at that point to end the scope.
Merlin 32 won't let you write " LDA #',' ". For some reason the
comma causes an error. IGenerator now has a "tweak operand format"
interface that lets us fix that.
The functions started by trying to pad a column out to a width,
then changed to pad things to a certain length. What they really
should be doing is padding the start of an entry to a specified
column. This is much more natural and avoids a trim operation.
The only change to the output is to ORG statements from the HTML
exporter, which are now formatted correctly.
Unlike 64tass and Merlin, which allow you to redefine symbols, ACME
uses "zones" that provide scope for local variables. This means
that, at the point of a local variable table definition, we have to
start a new zone and output the full set of active symbols, not just
the newly-defined ones. (If you set the "clear previous" flag in
the LvTable there's no difference.)
We could do a bit better by only outputting the symbols that are
actually used within the zone, similar to what we do for global
project/platform symbols, but that's a bunch of work for questionable
benefit.
Variables are now handled properly end-to-end, except for label
uniquification. So cc65 and ACME can't yet handle a file that
redefines a local variable.
This required a bunch of plumbing, but I think it came out okay.
Previously, we used the default character encoding from the project
properties to determine how strings and character constants in the
entire source file should be encoded. Now we switch between
encodings as needed. The default character encoding is no longer
relevant.
High ASCII is now an actual encoding, rather than acting like ASCII
that sometimes doesn't work. Because we can do high ASCII character
operands with "| $80", we don't output a .enc to switch from ASCII
to high ASCII unless we need to generate a string. (If we're
already in high ASCII mode, the "| $80" isn't required but won't
hurt anything.)
We now do a scan up front to see if ASCII or high ASCII is needed,
and only output the .cdefs for the encodings that are actually used.
The only gap in the matrix is high ASCII DCI strings -- the ".shift"
pseudo-op rejects text if the string doesn't start with the high
bit clear.
I didn't think it made sense, but I found something that used it,
so apparently it's a thing. This updates the operand editor to
let you choose PETSCII+DCI, and updates the assemblers to handle
it correctly (really just 64tass, since the others either don't
have a DCI directive or don't deal with PETSCII at all).
Changed the char-encoding sample from "bad dcI" to "pet dcI", and
updated the documentation.
The documentation for 64tass says you're required to pass "--ascii"
when the source file is ASCII (as opposed to PETSCII). We were
ignoring this, but it turns out that everything works a bit better
if we don't.
So we now pass "--ascii" on the command line, and add a two-line
character encoding definition to every file that is generated with
ASCII as the default encoding. The sg_petscii and sg_screen
encodings go away, as PETSCII is now the default, and we can use the
built-in "screen" encoding.
The PseudoOpNames class is increasingly being used in situations
where mutability is undesirable. This change makes instances
immutable, eliminating the Copy() method and adding a constructor
that takes a Dictionary. The serialization code now operates on a
Dictionary instead of the class properties, but the JSON encoding is
identical, so this doesn't invalidate app settings file data.
Added an equality test to PseudoOpNames. In LineListGen, don't
reset the line list if the names haven't actually changed.
Use a table lookup for C64 character conversions. I figure that
should be faster than multiple conditionals on a modern x64 system.
Fixed a 64tass generator issue where we tried to query project
properties in a call that might not have a project available
(specifically, getting FormatConfig values out of the generator for
use in the "quick set" buttons for Display Format).
Fixed a regression test harness issue where, if the assembler reported
success but didn't actually generate output, an exception would be
thrown that halted the tests.
Increased the width of text entry fields on the Pseudo-Op tab of app
settings. The previous 8-character limit wasn't wide enough to hold
ACME's "!pseudopc". Also, use TrimEnd() to remove trailing spaces
(leading spaces are still allowed).
In the last couple of months, Win10 started stalling for a fraction
of a second when executing assemblers. It doesn't do this every
time; mostly it happens if it has been a while since the assembler
was run. My guess is this has to do with changes to the built-in
malware scanner. Whatever the case, we now change the mouse pointer
to a wait cursor while updating the assembler version cache.
The 64tass generator now uses the "default text encoding" project
property to determine how readable text should be encoded. For
example, if the property is set to PETSCII, an ASCII-to-PETSCII
encoding table is generated at the top of the output file.
A delimiter definition is four strings (prefix, open, close, suffix)
that are concatenated with the character or string data to form an
operand. A delimiter set is a collection of delimiter definitions,
with separate entries for each character encoding.
This is a convenient way to configure Formatter objects, import and
export data from the app settings file, and manage the UI needed to
allow the user to customize how things look.
The full set of options didn't fit on the first app settings tab, so
there's now a separate tab just for specifying character and string
delimiters. (This might be overkill, but there are various plausible
scenarios that make use of it.)
The delimiters for on-screen display of strings can now be
configured.
The previous functions just grabbed 62 characters and slapped quotes
on the ends, but that doesn't work if we want to show strings with
embedded control characters. This change replaces the simple
formatter with the one used to generate assembly source code. This
increases the cost of refreshing the display list, so a cache will
need to be added in a future change.
Converters for C64 PETSCII and C64 Screen Code have been defined.
The results of changing the auto-scan encoding can now be viewed.
The string operand formatter was using a single delimiter, but for
the on-screen version we want open-quote and close-quote, and might
want to identify some encodings with a prefix. The formatter now
takes a class that defines the various parts. (It might be worth
replacing the delimiter patterns recently added for single-character
operands with this, so we don't have two mechanisms for very nearly
the same thing.)
While working on this change I remembered why there were two kinds
of "reverse" in the old Merlin 32 string operand generator: what you
want for assembly code is different from what you want on screen.
The ReverseMode enum has been resurrected.
The previous code output a character in single-quotes if it was
standard ASCII, double-quotes if high ASCII, or hex if it was neither
of those. If a flag was set, high ASCII would also be output as
hex.
The new system takes the character value and an encoding identifier.
The identifier selects the character converter and delimiter
pattern, and puts the two together to generate the operand.
While doing this I realized that I could trivially support high
ASCII character arguments in all assemblers by setting the delimiter
pattern to "'#' | $80".
In FormatDescriptor, I had previously renamed the "Ascii" sub-type
"LowAscii" so it wouldn't be confused, but I dislike filling the
project file with "LowAscii" when "Ascii" is more accurate and less
confusing. So I switched it back, and we now check the project
file version number when deciding what to do with an ASCII item.
The CharEncoding tests/converters were also renamed.
Moved the default delimiter patterns to the string table.
Widened the delimiter pattern input fields slightly. Added a read-
only TextBox with assorted non-typewriter quotes and things so
people have something to copy text from.
We've been treating ASCII strings and instruction/data operands as
ambiguous, resolving low vs. high when generating output for the
display or assembler. This change splits it into two separate
formats, simplifying output generation.
The UI will continue to treat low/high ASCII as as single thing,
selecting the format appropriately based on the data. There's no
reason to have two radio buttons that are never both enabled.
The data operand string functions need some additional work, but
that overlaps substantially with the upcoming PETSCII changes, so
for now all strings set by the data operand editor are low ASCII.
The file format has changed again, but since there hasn't been a
release since the previous change, I'm leaving the file format
at v2. Code has been added to resolve the ASCII mode when loading
a v1 project file.
This removes some complexity from the assembly code generators.
DCI is handled with the ".shift" pseudo-op. The .null, .ptext,
and .shift operators all work correctly with escaped characters,
so we no longer redo those.
This generalizes the string pseudo-operand formatter, moving it into
the Asm65 library. The assembly source generators have been updated
to use it. This makes the individual generators simpler, and by
virtue of avoiding "test runs" should make them slightly faster.
This also introduces byte-to-character converters, though we're
currently still only supporting low/high ASCII.
Regression test output is unchanged.
We used to use type="String", with the sub-type indicating whether
the string was null-terminated, prefixed with a length, or whatever.
This didn't leave much room for specifying a character encoding,
which is orthogonal to the sub-type.
What we actually want is to have the type specify the string type,
and then have the sub-type determine the character encoding. These
sub-types can also be used with the Numeric type to specify the
encoding of character operands.
This change updates the enum definitions and the various bits of
code that use them, but does not add any code for working with
non-ASCII character encodings.
The project file version number was incremented to 2, since the new
FormatDescriptor serialization is mildly incompatible with the old.
(Won't explode, but it'll post a complaint and ignore the stuff
it doesn't recognize.)
While I was at it, I finished removing DciReverse. It's still part
of the 2005-string-types regression test, which currently fails
because the generated source doesn't match.
The 65816 definition makes it a two-byte instruction, like COP. On
the 6502 it acted like a two-byte instruction, but in practice very
few assemblers treat it that way. Very few humans, for that matter.
So it's now treated as a single byte instruction, with the following
byte encoded as a data value.
This worked, sort of. The problem is that SourceGen will revert to
hex output in certain situations, such as a broken symbolic
reference. There happens to be one in the ZIPPY example, and it's
on a relative branch.
The goal with the segment stuff is to allow cc65 to treat the
source as relocatable code. In that context, a relative branch to
an absolute address doesn't make any sense, so the assembler reports
a range error.
We don't currently have a mechanism that guarantees no references
are broken (and no affordance for finding them), so we can't make
this mode the default yet.
Instead, we continue to use the generic config, but generate the
correct set of lines as comments.
(issue #39)
The cc65 assembler runs in a single pass, which means forward
address references default to 16 bits. For zero-page references
we have to add an explicit width disambiguator. (This is an
unusual situation that only occurs if you have a zero-page .ORG
in the file after code that references it.)
With this change, 2014-label-dp passes, and no other regression
tests were affected.
(issue #40)
The 2014-label-dp test now passes. Prior regression tests are
unaffected.
Also, renamed an IGenerator interface to more accurately reflect
its role.
(issue #37)
To avoid confusing the assembler, expressions with a leading
parenthesis like "(foo & $ffff) + 1" are prefixed with a "0+". This
is not necessary if the operand begins with a '#'.
(issue #16)
We now insert parenthesis as needed. This can cause problems in
some situations, so we always prefix parenthetical expressions with
"0+", which looks goofy and is unnecessary for immediate operands.
But it does generate working source code.
Renamed the "simple" expression mode to "common", as it's not
particularly simple but is what you'd expect most assemblers to do.
(OTOH, life has been full of surprises.)
(issue #16)
Gave cc65 its own expression generator, as the precedence table seems
atypical if not unique. Configured 64tass to use the "simple"
expression mode.
Added some operations on a 32-bit constant to 2007-labels-and-symbols
to exercise the current worst-case expression (shift + AND + add).
Tweaked the Merlin expression generator to handle it.
(issue #16)
Most tests pass, but 2007-labels-and-symbols fails because the
expressions recognized by 64tass don't match up with either of the
other assemblers.
This is currently using a workaround for the local label syntax.
64tass uses '_' as the prefix, which is unfortunate since SourceGen
explicitly allowed underscores in labels. (So does 64tass for that
matter, but it treats labels specially when the '_' comes first.)
We will need to rename any non-local user labels that start with '_'.
(issue #16)
