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ca65 compatibility

Use ca65 compatibility in 6502-family and NES projects, with syntax and limits.

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The 65xx plugin targets practical ca65 source compatibility: every plugin-owned CPU, a useful dotted directive subset, and selected expression, scope, and macro forms. It does not emit cc65 relocatable objects, libraries, relocation records, general ld65 configurations, or debug/listing metadata.

Status meanings:

Supported: accepted with the documented ca65 source meaning within the target's image model.
Partial: useful source behavior is implemented, but object, linker, or an advanced ca65 semantic is intentionally absent.
Unsupported: rejected rather than silently ignored.

6502 family behavior

CPUs & Instructions

Feature	Status	Notes
`.setcpu` / `.cpu`, `.pushcpu`, `.popcpu`	Supported	Selects and stacks the active encoder during assembly.
CPU shorthand directives	Supported	`.p02`, `.p02x`, `.pdtv`, `.psc02`, `.pc02`, `.pwc02`, `.pce02`, `.p4510`, `.p45gs02`, `.p6280`, and `.pm740`.
CPU conditionals	Supported	Matching `.ifp*` forms for every plugin-owned CPU.
CPU names	Supported	`6502`, `6502X`, `6502DTV`, `65SC02`, `65C02`, `W65C02`, `65CE02`, `4510`, `45GS02`, `HuC6280`, and `M740`. 65816-derived CPUs remain SNES-plugin-owned.
Legal, undocumented, and vendor instructions	Supported	Includes 6502X, HuC6280, M740, 65CE02/4510, and 45GS02 forms represented by the declarative catalogs.

Expressions & Symbols

Feature	Status	Notes
Hex, binary, decimal, and octal literals	Supported	`$`, `%`, decimal, and ca65 `@` octal syntax.
Low/high/bank operators	Supported	Unary `<`, `>`, and `^`.
Pseudo-functions	Supported	`.defined`, `.lobyte`, `.hibyte`, `.bankbyte`, `.loword`, and `.hiword`.
Inequality and symbol assignment	Supported	`<>`, `=`, and `:=` source forms.
Address-size forcing	Supported	`z:`, `a:`, and `f:` are carried into architecture-owned operand classification.
Global, cheap-local, and unnamed labels	Supported	Includes `@name`, `:`, `:+`, `:++`, `:-`, and `:--`. File-local symbols remain isolated across included assembly units.
`.scope` / `.endscope`, `.proc` / `.endproc`, `Scope::Name`	Partial	Flattened into file-local symbol keys. Scope type declarations, address-size annotations, and object visibility metadata are not modeled.
`.export` / `.import`	Partial	Resolves symbols across source files assembled in one session. No relocatable external symbol records are emitted.
`.exportzp`, `.importzp`, `.globalzp`, `.forceimport`, `.autoimport`	Unsupported	These require relocatable object/linker semantics and produce an explicit diagnostic.

Directives & Control Flow

Feature	Status	Notes
`.byte` / `.byt`, `.word` / `.addr`, `.dbyt`	Supported	Includes ca65 byte ordering.
`.dword`, `.faraddr`, `.lobytes`, `.hibytes`	Supported	Emits 32-bit, 24-bit, or selected-byte values respectively.
`.res`, `.align`, `.org`	Supported	Operates directly on the selected flat or iNES image.
`.include`, `.incbin`	Supported	`.incbin` uses ca65 `file, offset, size` arguments.
`.if`, `.elseif`, `.else`, `.endif`, `.ifdef`, `.ifndef`	Supported	Dotted forms lower to the shared conditional engine.
`.assert`	Partial	A false assertion stops assembly with its message. ca65 warning/link-time assertion actions are not reproduced.
`.undefine`	Supported	Removes a symbol definition through the shared symbol engine.
`.segment`, `.pushseg`, `.popseg` on `65xx.ca65-raw`	Partial	Segment names and stack intent are accepted while bytes remain in source order in one flat image.
`.segment` on `65xx.nes`	Partial	Implements the selected MEMORY/SEGMENTS load/run/fill model used by the NES integration fixture. It is not a general ld65 linker.
`.constructor`, `.destructor`, `.interruptor`, `.reloc`, `.debuginfo`	Unsupported	Object/linker/debug directives produce an explicit diagnostic.

Macros & Repetition

Feature	Status	Notes
`.macro` / `.endmacro` and bare invocation	Supported	Comma-separated parameters and ca65 `\parameter` substitution are supported.
`.repeat` / `.endrepeat`	Supported	Optional named repeat counters are available as ordinary expressions.
`.local`, `.exitmacro`	Unsupported	Rejected with a macro-compatibility diagnostic.
Token-list/string macros, `.match`, `.xmatch`, `.mid`, `.left`, `.right`	Unsupported	The advanced ca65 token macro language is not implemented.