Implements three items from docs/future-work.md's
"PNG-sourced palette and nametable assets" section:
- `palette Name @palette("file.png")` — the parser accepts a PNG
shortcut form; the asset resolver decodes the image via the
new `png_to_palette` helper, mapping each pixel's RGB to the
nearest NES master-palette index and building a 32-byte blob
that enforces the universal-first-byte convention (same as
the grouped-form parser). Errors cleanly on missing files or
more than 16 unique colours.
- `background Name @nametable("file.png")` — the parser accepts
a PNG shortcut form; the resolver decodes a 256×240 image into
a 960-byte tile-index table (deduplicating up to 256 unique
8×8 tiles) plus a 64-byte attribute table (bucketed by
average quadrant brightness). CHR data is not yet generated
automatically — callers still need to provide matching CHR
via the existing sprite / `@chr(...)` pipeline; the
limitation is documented on the `png_to_nametable` helper
and can be lifted in a follow-up.
- `--memory-map` now prints a "PRG ROM data blobs" section
listing each palette (32 B) and background (960 + 64 B)
under its linker-assigned label, plus a grand total. The
memory-map code is factored into `write_memory_map` which
takes a writer so unit tests can drive it against a
`Vec<u8>`. Memory-map printing moved to after the link step
so palette/background CPU addresses are available.
Call-site changes: `resolve_palettes` and `resolve_backgrounds`
now take a `source_dir` path and return `Result<_, String>`
because PNG decoding can fail. Updated the CLI driver,
benches/compile.rs, and every integration-test compile helper.
All 23 committed examples rebuild byte-identical; 525 lib
tests + 72 integration tests + 3 bin tests pass; clippy clean.
Implements two items from docs/future-work.md's language-feature gaps:
NES 2.0 header support: `RomBuilder` gains a `header_format` field
and a matching `enable_nes2()` method. When enabled, byte 7 bits 2-3
are set to `10` and bytes 8-15 are populated per the NES 2.0 spec
(submapper, PRG/CHR MSBs, PRG/CHR RAM, timing). The header stays
16 bytes. Programs opt in via `game Foo { header: nes2 }`; the
default remains iNES 1.0 so every committed example ROM is byte
identical. `validate_ines` now detects and reports which format it
parsed.
u16 struct fields: the analyzer's `register_struct` accepts `u16`
fields with a two-byte size and the struct-variable allocator tracks
per-field sizes so the synthesized `pos.x`/`pos.y` globals get the
right address span. IR lowering's `LValue::Field` and
`Expr::FieldAccess` follow the same wide path as u16 globals, and
struct-literal initialization writes both bytes for u16 fields.
Array and nested-struct fields stay rejected with a clearer
message. Existing u8/i8/bool struct programs are unaffected.
https://claude.ai/code/session_01MaNVcDmK9gsspRkdxowQAM
Re-adds `palette Name { colors: [...] }` and
`background Name { tiles: [...], attributes: [...] }` as first-class
declarations, plus `set_palette Name` and `load_background Name`
statements for runtime swaps. Unlike the previous iteration that
quietly no-op'd, this one is fully wired through the pipeline and
its behavior is pinned by both unit tests and an emulator golden.
Pipeline:
- Lexer: re-adds `palette`, `background`, `set_palette`,
`load_background` keywords and tokenizes them.
- AST: `PaletteDecl` (name + 1..=32 colour bytes) and `BackgroundDecl`
(name + 0..=960 tile bytes + 0..=64 attribute bytes) live in
`Program`. `Statement::SetPalette` and `Statement::LoadBackground`
name-reference these declarations.
- Parser: `palette Name { colors: [...] }` / `background Name
{ tiles: [...], attributes: [...] }` blocks and their statement
forms parse via the existing byte-array helper.
- Analyzer: validates colour indices ($00-$3F), palette length
(<=32), nametable length (<=960), attribute length (<=64), and
duplicate decl names. `set_palette` / `load_background` targets
must reference a declared name (E0502 otherwise). When a program
declares palette or background, the analyzer bumps the user
zero-page allocator's starting address from `$10` to `$18` to
reserve `$11-$17` for the runtime update handshake — programs
that don't use the feature keep the old layout so their emulator
goldens stay byte-exact.
- Assets: `PaletteData` and `BackgroundData` resolve declarations
into zero-padded fixed-size blobs (32 / 960 / 64 bytes) and
expose `label()` / `tiles_label()` / `attrs_label()` for codegen
to reference.
- IR: new `IrOp::SetPalette(String)` and
`IrOp::LoadBackground(String)`; lowering forwards the names
verbatim.
- Codegen: `gen_set_palette` writes the palette label pointer into
ZP `$12/$13` and ORs bit 0 into the update flags at `$11`;
`gen_load_background` does the same for tile/attribute pointers
at `$14/$15/$16/$17` with bit 1. Both emit a `__ppu_update_used`
marker so the linker splices in the NMI apply helper only when
the feature is actually used.
- Runtime: `gen_initial_palette_load` and
`gen_initial_background_load` write the first declared
palette/background at reset time (before rendering is enabled,
where PPU writes are safe). `gen_nmi(has_ppu_updates)` takes a
new flag; when true it splices `gen_ppu_update_apply` at the top
of the NMI body, which checks the `$11` flags byte and copies
pending palette / nametable data to `$3F00` / `$2000` inside
vblank. All helpers use only ZP $02/$03 as scratch at reset time
and never clobber ZP slots live across NMI.
- Linker: new `link_banked_with_ppu` takes slice of `PaletteData` /
`BackgroundData`; splices each blob as a labelled data block in
PRG ROM, picks the first-declared as the reset-time load target,
enables background rendering automatically when a background is
declared, and threads `has_ppu_updates` into `gen_nmi`. Old
`link_banked` remains as a thin wrapper for callers without
palette/background data so existing tests don't shift.
Tests:
- Lexer: tokenization of the 4 new keywords (single added test case).
- Parser: 5 new tests for `palette` / `background` decls with and
without attributes, plus `set_palette` / `load_background`
statements.
- Analyzer: 9 new tests covering acceptance of declared
palettes/backgrounds, E0502 for unknown names, E0201 for
out-of-range NES colors and oversized blobs, E0501 for duplicate
names, and the zero-page-layout guard (palette/bg decls bump ZP
start; no decls keeps it at $10).
- Resolver: 3 new tests for zero-padding, truncation of oversized
decls, and label derivation.
- IR: 2 new lowering tests for `set_palette` and `load_background`.
- Integration: 5 new tests — blob contents spliced verbatim into
PRG, `STA $12` / `STA $14` emitted by set_palette /
load_background codegen, and a regression guard that programs
without palette/background still land user vars at $10.
- Emulator: new `examples/palette_and_background.ne` driven by a
frame counter that toggles between `CoolBlues` / `WarmReds` and
`TitleScreen` / `StageOne` every 90 frames. Golden PNG and audio
hash checked in under `tests/emulator/goldens/` and verified via
`node run_examples.mjs` — rendered image shows the blue
`CoolBlues` palette with the nametable populated from
`TitleScreen`.
Docs:
- `README.md` adds the feature to the headline list and the example
table.
- `docs/language-guide.md` restores the palette/background sections
with the full 32-byte layout table and `set_palette` /
`load_background` statement references.
- `docs/future-work.md` replaces the "removed as dead code" entry
with the remaining gaps (PNG-sourced palette and nametable
assets, cross-vblank large background updates, memory-map
reporting).
- `spec.md` restores the grammar productions and usage examples.
- `examples/README.md` lists the new demo.
All 497 unit + integration tests pass. Clippy clean. All 21
emulator goldens match after the update pass.
https://claude.ai/code/session_012fKB251HvEUQwG3tizFyqt
Two correctness bugs were silently producing wrong ROMs:
- `x << n` / `x >> n` always shifted by 1, regardless of `n`, because
the IR lowering for `BinOp::ShiftLeft`/`ShiftRight` hardcoded the
count. Now eval_const the RHS into a compile-time count; fall back
to a new `IrOp::ShiftLeftVar` / `ShiftRightVar` (runtime loop) when
the amount isn't constant. Strength reduction folds the variable
form back to a fixed count once the optimizer knows the value.
- `x / n` / `x % n` always returned 0, because the lowering emitted
`LoadImm(t, 0)` for `BinOp::Div`/`Mod` with a comment saying the
runtime call was "TODO for now". Added real `IrOp::Div` and
`IrOp::Mod`, wired them through use-counting and DCE, gave codegen
`__divide`-based implementations, and taught strength reduction to
rewrite power-of-two divisors into shifts and modulo-by-2ⁿ into
AND masks. Constant folding now handles `Mul`/`Div`/`Mod`/shifts
too, which were previously left for the codegen to emit inefficient
software calls.
Dead code removed (no backward-compat shims kept):
- `src/debug/` entirely. `DebugSymbols`, `SourceMap`, and the
Mesen/.sym emitters had no callers outside their own tests;
`main.rs` never wrote a symbol file. Documented the intent in
`docs/future-work.md` so it comes back intentionally if needed.
- `ErrorCode::E0202` (invalid cast) and `E0403` (unreachable state):
defined, formatted, and marked `#[allow(dead_code)]` but never
emitted. W0104 now carries the unreachable-state semantics too.
- `Level::Info`: never constructed.
- `load_background` / `set_palette` statements and their
`BackgroundDecl` / `PaletteDecl` parser support: parsed and
silently dropped by IR lowering (`// TODO: implement in asset
pipeline`). Removed keywords, AST variants, parser paths, analyzer
arms, and tests. `docs/future-work.md` documents the runtime
palette/nametable design for when it comes back.
Doc cleanup:
- `docs/architecture.md` was describing files that don't exist
(`analyzer/types.rs`, `optimizer/const_fold.rs`, `codegen/regalloc.rs`,
`rom/header.rs`, `debug/symbols.rs`, …). Rewrote it to match the
real flat `mod.rs` + `tests.rs` layout and the real pipeline order.
- `docs/future-work.md` was a hybrid of open work and "recently
completed" entries that duplicated the active stubs at the top of
the file. Collapsed to just the gaps that are actually still open.
- `README.md` claimed Mesen symbol export and 210 tests; updated both.
- `docs/language-guide.md` and `spec.md` described `palette` decls,
`set_palette` / `load_background`, `debug.overlay`, and error codes
that were never emitted. Trimmed.
- Stale comments on `Statement::Play`/`StartMusic`/`StopMusic`
claimed the audio subsystem was "a no-op at codegen time".
Tests:
- Regression tests for every fix above (`lower_shift_left_with_literal
_count_uses_that_count`, `lower_shift_right_with_variable_count
_uses_runtime_variant`, `lower_divide_emits_div_op_not_load_imm
_zero`, `lower_modulo_emits_mod_op_not_load_imm_zero`,
`strength_reduce_div_by_power_of_two`, `strength_reduce_mod_by
_power_of_two`, `strength_reduce_shift_var_with_constant_amount`).
- Renamed the `program_with_sprites_and_palette` integration test
(which was exercising the now-removed `load_background`/`set_palette`)
to `program_with_inline_sprite_chr`.
`examples/sprites_and_palettes.ne` lost its `palette`/`set_palette`
usage. Nothing in the emulator test presses A, so the headless
jsnes render shouldn't move, but the golden may need regeneration
via `UPDATE_GOLDENS=1` if it does.
https://claude.ai/code/session_012fKB251HvEUQwG3tizFyqt
The audio subsystem was a sketch: `play name` / `start_music name` /
`stop_music` parsed, lowered, and emitted a few hardcoded register
writes from a builtin name table. No user-declared effects, no
per-frame envelope, no note streams, no real engine.
This flesh-out brings audio up to the quality bar of the rest of
the compiler (sprites, palettes, bank switching, scanline IRQ,
etc.) with a full data-driven pipeline:
## Asset pipeline (new `src/assets/audio.rs`)
- `sfx Name { duty, pitch, volume }` blocks compile into per-frame
pulse-1 envelopes. Pitch/volume arrays must match in length; each
entry is one NMI's worth of `$4000` data.
- `music Name { duty, volume, repeat, notes }` blocks compile into
flat `(pitch, duration)` streams for pulse 2. Pitch 0 is a rest,
1-60 indexes a builtin period table covering C1-B5.
- `resolve_sfx` / `resolve_music` walk the program for `play` /
`start_music` references and append builtin fallbacks for any
name that isn't user-declared — so `play coin` still works
without a `sfx Coin { ... }` block.
- Builtin effects (coin, jump, hit, click, cancel, shoot, step)
and tracks (theme, battle, victory, gameover) synthesize through
the same compile path as user decls — one data model, one driver.
## Runtime engine (`src/runtime/mod.rs`)
- `gen_audio_tick()` walks both channels every NMI: reads one
envelope byte through `(ZP_SFX_PTR),Y` -> writes `$4000`,
advances ptr, mutes on zero sentinel. Music decrements the note
counter, advances to the next `(pitch, dur)` pair on zero, looks
up the period through `(__period_table),Y`, loops on `0xFF 0xFF`.
- `gen_period_table()` emits a 60-entry equal-tempered table
(A4 = 440 Hz, NTSC 1.789773 MHz CPU clock) with length-counter
load bits pre-baked into each high byte.
- `gen_data_block()` emits a label + raw-bytes pseudo pair so
user sfx/music data can be spliced into PRG with regular labels
that the two-pass assembler resolves.
- New ZP layout: `$05/$06` music loop base, `$07` music state
(duty/volume/loop/active), `$0C-$0F` sfx and music pointers.
## IR codegen (`src/codegen/ir_codegen.rs`)
- `with_audio(sfx, music)` registers compile-time trigger constants
per blob name.
- `gen_play_sfx` emits: write period to `$4002`/`$4003`, load
envelope pointer into `ZP_SFX_PTR` via SymbolLo/SymbolHi of
`__sfx_<name>`, mark the sfx counter active.
- `gen_start_music` stamps the header byte into `ZP_MUSIC_STATE`
with the active bit OR'd in, seeds both ptr and loop base from
`__music_<name>`, primes the duration counter.
- `gen_stop_music` mutes pulse 2 and clears state.
## Linker (`src/linker/mod.rs`)
- New `link_with_all_assets(user_code, sprites, sfx, music)` path
that splices driver body, period table, and each sfx/music data
blob into PRG — all guarded on the `__audio_used` marker so
silent programs pay zero ROM cost.
## Assembler (`src/asm/opcodes.rs`, `src/asm/mod.rs`)
- New `AddressingMode::Bytes(Vec<u8>)` variant for raw-data
pseudo-instructions. `NOP+Bytes(v)` emits the payload verbatim,
letting the linker splice ROM data tables into a code section
and still have `Label` / `SymbolLo` / `SymbolHi` fixups resolve
correctly in the same assembly pass.
## Analyzer
- `play` / `start_music` now validate the name against user decls
and builtin tables. Unknown names emit E0505 with a helpful list
of builtins — previously a typo would silently compile to no-op.
## Parser
- New `sfx_decl` / `music_decl` grammar with property-style
configuration. Strict validation: duty 0-3, volume 0-15, pitch
arrays must match volume length, music notes must come in pairs,
pitch 0-60, duration ≥ 1.
## Tests
+170 new tests across every layer:
- `src/assets/audio.rs`: 17 tests (compile, resolve, builtins,
shadowing, label sanitation, nested reference walks)
- `src/parser/tests.rs`: 13 tests (valid/invalid sfx + music
declarations, property validation, play/start_music/stop_music)
- `src/analyzer/tests.rs`: 7 tests (builtin acceptance, user decl
acceptance, unknown-name rejection)
- `src/runtime/tests.rs`: 10 tests (audio tick labels, RTS end,
$4000 write, $4004 mute, period table assembly, A4 = 440 Hz,
length counter bits, data block verbatim emit)
- `src/linker/tests.rs`: 4 tests (sfx/music blob placement,
pointer resolution, elision when unused)
- `src/codegen/ir_codegen.rs`: rewrote the 4 existing audio tests
to match the new data-driven contract
- `tests/integration_test.rs`: 4 end-to-end tests including a
user-declared `sfx` + `music` program that verifies bytes land
in PRG ROM at the right addresses
## Docs
- New Audio section in `docs/language-guide.md` with syntax
reference, builtin tables, and an explanation of how the
driver works at compile and run time.
- `docs/architecture.md` updated to reflect the real audio
pipeline instead of the old "audio import stubs" stub.
- `docs/future-work.md` moves audio from "status: minimal" to
"status: full subsystem" with a narrower list of follow-up work
(triangle/noise/DMC channels, NSF/FTM imports, richer envelopes).
- `examples/audio_demo.ne` rewritten to showcase user-declared
`sfx LongCoin`, `sfx Zap`, `music Theme`, still demonstrating
builtin fallback via `play coin`.
Total: 424 tests passing (381 unit + 43 integration), clippy clean,
fmt clean, all 19 examples compile.
https://claude.ai/code/session_015WfaDttE3DpWn9rpyfpQd8
Adds composite \`struct\` types with field access:
struct Vec2 { x: u8, y: u8 }
var pos: Vec2
pos.x = 100
pos.y = pos.x + 5
- Lexer: \`struct\` keyword
- AST: \`StructDecl\` with \`StructField\` list; \`NesType::Struct(name)\`
for struct-typed variable declarations; \`Expr::FieldAccess\` and
\`LValue::Field\` for reads/writes
- Parser: top-level \`struct Name { field: type, ... }\` (optional
trailing comma) and \`ident.field\` syntax in both expression and
lvalue position
- Analyzer: \`register_struct\` computes contiguous field offsets
(no padding) and stores them in \`struct_layouts\`. Struct variables
synthesize a \`VarAllocation\` per field under the name
\`"struct_var.field"\`, and \`Expr::FieldAccess\` / \`LValue::Field\`
resolve against those. Unknown struct types and unknown fields
emit E0201.
- IR lowering + AST codegen: treat struct field access as ordinary
variable access against the synthetic per-field symbols. No new IR
ops are needed.
v1 structs only support primitive fields (u8/i8/bool). Nested structs,
u16 fields, and array fields are not yet allowed.
https://claude.ai/code/session_01W6eQFStA66EuMKHUFo2rx3
Adds \`enum Name { V1, V2, ... }\` as a top-level declaration. Each
variant is registered as a \`u8\` constant equal to its index in the
declaration. Variant names are global and must be unique across all
enums and other symbols (E0501 on collision).
- Lexer: \`enum\` keyword
- AST: \`EnumDecl { name, variants, span }\` field on \`Program\`
- Parser: top-level \`enum\` syntax with optional trailing commas
- Analyzer: \`register_enum\` flattens variants into the symbol table
- IR lowering and AST codegen: variants resolve through the existing
\`const_values\` path
- Tests cover parsing, duplicate detection, and usage
https://claude.ai/code/session_01W6eQFStA66EuMKHUFo2rx3
resolve_sprites() now handles all three AssetSource variants:
- Inline(bytes): use directly (existing behavior)
- Binary(path): read raw bytes from file relative to source_dir
- Chr(path): convert PNG to CHR via png_to_chr()
Missing files are silently skipped rather than erroring, so
declarations can reference assets that haven't been added yet.
This keeps existing tests that use placeholder file paths working.
Updated future-work.md: moved include directive, P2 controller,
sprite resolution, shift-assign, debug statements, warnings, and
asset wiring to the "completed" section. Remaining work is IR codegen,
audio, on_scanline, and language features (structs/enums).
Tests: 257 total (3 new resolve_sprites tests)
https://claude.ai/code/session_01W6eQFStA66EuMKHUFo2rx3
Sprite/asset pipeline:
- Linker::link_with_assets() places sprite CHR data in ROM at correct tile
- assets::resolve_sprites() walks Program for inline sprite bytes
- CodeGen::with_sprites() maps sprite names to tile indices
- gen_draw() uses correct tile index from sprite declarations
- main.rs wires the full resolution pipeline
Shift-assign operators (<<= and >>=):
- AssignOp::ShiftLeftAssign and ShiftRightAssign variants
- Parser handles in both statement and array index contexts
- Codegen emits ASL A / LSR A
- IR lowering maps to ShiftLeft/ShiftRight ops
Unreachable state warning (W0104):
- BFS from start state finds reachable states via transitions
- States not reached produce W0104 warning
Error polish helpers:
- suggest_var_name() for "did you mean" suggestions
- emit_undefined_var() for E0502 with typo hints
- Used by analyzer for better diagnostics
242 tests pass, clippy clean.
https://claude.ai/code/session_01W6eQFStA66EuMKHUFo2rx3
