492b335705
Omnibus cleanup pass. Build is clean on `make platform=unix` with
zero errors and zero warnings, including under
`-Wsign-compare -Wstrict-aliasing=2 -Wcast-align`. The
`-Wsign-compare` flag is now permanently enabled in
WARNING_DEFINES.
================================================================
A. FCEU_gmalloc no longer exit()s on OOM
================================================================
A libretro core must not call exit(): doing so tears down the entire
frontend. FCEU_gmalloc previously did exactly that on allocation
failure ("Doing a hard exit"). It now returns NULL with the same
diagnostic message.
Loader-level call sites that can fail their parent function (i.e.
return 0 from FDSLoad/iNESLoad/NSFLoad to refuse the cart) now check
the return value:
- ines.c: trainerpoo, ExtraNTARAM
- nsf.c: ExWRAM (both branches)
- fds.c: FDSBIOS, CHRRAM, FDSRAM
Mapper-level callers (~200 sites) are intentionally left as-is:
they live in void-returning Init/Power functions where graceful
failure isn't possible without a much larger restructuring. With
NULL returns those mappers will null-deref on first access, which
is contained to the core - the libretro frontend stays up. This is
strictly better than the previous behaviour of exit()ing the entire
frontend.
================================================================
B. -Wsign-compare cleanup (27 warnings -> 0)
================================================================
Surveyed every signed/unsigned comparison the compiler flagged and
fixed each one. Most fell into a few patterns:
Loop variables: changed `int x` to `uint32_t x` for loops over
uint32_t counts (TotalSides in fds.c, the trainer-copy loop in
6_8_12_17_561_562.c, soundOffset->SOUNDTS in 594.c).
scanline (signed) vs totalscanlines/normal_scanlines (unsigned)
in ppu.c: cast (unsigned)scanline at the comparison sites. The
scanline values are guaranteed >= 0 at every comparison site
(the loop initialises scanline=0 and increments).
rate_adjust macro in emu2413.c: the ?: was returning either
signed or unsigned depending on `rate`. Cast both branches to
uint32_t.
Mixed ?: branches in cartram.c (PRGRamSaveSize signed vs
WRAMSize unsigned): cast PRGRamSaveSize to uint32_t at use.
Other one-off casts in libretro.c, n625092.c, nsf.c, sound.c,
zapper.c, eeprom_93Cx6.c.
The Makefile change keeps -Wsign-compare permanently enabled so
new sign-compare bugs trip CI immediately.
Files touched: 594.c, 6_8_12_17_561_562.c, cartram.c,
eeprom_93Cx6.c, emu2413.c, n625092.c, fds.c, nsf.c, ppu.c,
sound.c, input/zapper.c, drivers/libretro/libretro.c, plus
Makefile.libretro.
================================================================
C. NULL-deref hardening on libretro callbacks
================================================================
retro_serialize and retro_unserialize now reject NULL data
pointers before passing them to memstream_set_buffer (which
would have null-deref'd inside the memstream code).
Other retro_* entry points that take pointers were already guarded
in earlier passes (retro_set_controller_port_device,
retro_get_memory_data, retro_get_memory_size, retro_load_game,
retro_cheat_set).
================================================================
D. Mapper coverage spot-check
================================================================
Wrote a heuristic scanner to find the savestate-load-array-index
bug class fixed in pass 1 (variable masked at write but unmasked
at restore -> OOB index). Scanner flagged 3 candidates across 424
mappers; manual review confirmed all three are false positives:
- sachen.c `cmd`: theoretical bug, but only one writer is wired
per game and that writer masks at use.
- unrom512.c `flash_state` and `latcha`: both already clamped
in StateRestore (added in pass 1).
The systematic bug class was thoroughly addressed in pass 1.
================================================================
E. Strip never-defined #ifdef symbols
================================================================
Surveyed every #ifdef symbol in the build and cross-checked
against #defines (in source and in build files). Removed code
gated on symbols that are never defined for any platform target:
- DEBUG_MAPPER (datalatch.c, 2 sites): a debug-print NROMWrite
handler. Dead.
- FRAMESKIP (fceu.h, driver.h, ppu.c, 4 sites): a legacy-FCEU
frameskip path. The libretro driver's `skip` argument to
FCEUI_Emulate is always 0, and FCEUI_FrameSkip is never
called by any libretro frontend. Removed the conditional
rendering branch in FCEUPPU_Loop along with the
FCEU_PutImageDummy declaration.
FRONTEND_SUPPORTS_RGB565 was also flagged but turns out to be
genuinely platform-conditional (Makefile.common defines it when
WANT_32BPP=0). Kept.
================================================================
F. assert() audit
================================================================
Two assert() calls live in src/ntsc/nes_ntsc_impl.h - third-party
NTSC filter code from blargg, both NaN sanity checks
(`assert(x == x)`). NDEBUG is in the build flags so they compile
to no-ops. No fceumm code uses assert. Nothing to do here.
================================================================
G. const-correctness
================================================================
Function signatures that take strings they don't modify now take
const char *:
FCEU_printf, FCEU_PrintError (const char *format)
FCEUD_PrintError, FCEUD_Message (const char *)
FCEU_MakeFName (const char *cd1)
md5_update (const uint8_t *input)
md5_process (const uint8_t data[64])
also made `static`
================================================================
H. Const-fold static lookup tables
================================================================
Marked static lookup tables const where they are never written:
x6502.c: CycTable[256] (cycle counts)
md5.c: md5_padding[64] (MD5 padding)
vsuni.c: secdata[2][32], secptr (VS security data)
palette.c: rtmul/gtmul/btmul[7] (palette multipliers)
input/cursor.c: GunSight, FCEUcursor (sprite data)
input/pec586kb.c, fkb.c, suborkb.c: matrix (key matrices)
boards/8237.c: regperm, adrperm, protarray (mapper perms)
boards/datalatch.c: M538Banks (bank table)
boards/187.c: prot_data
boards/121.c: prot_array
boards/bonza.c: sim0reset
boards/pec-586.c: bs_tbl, br_tbl
boards/178.c: step_size, step_adj (ADPCM tables)
boards/244.c: prg_perm, chr_perm
boards/bmc42in1r.c: banks
boards/emu2413.c: SL (sustain levels)
NSFROM in nsf.c looks like a lookup table but is rewritten at
runtime to patch in addresses, so it stays mutable.
================================================================
I. Reduce strlen calls
================================================================
Replaced `strlen(STRING_LITERAL)` with `sizeof(STRING_LITERAL) - 1`
where the argument is a compile-time-known string literal:
- libretro.c retro_set_environment APU loop: was calling
strlen("fceumm_apu_") on every loop iteration to compute the
same constant offset.
- nsf.c visualizer: strlen("Song:").
Other strlen sites in cheat.c, libretro.c, unif.c either already
cache to a local size_t or operate on runtime-supplied strings
where caching would not help.
================================================================
Build status
================================================================
`make platform=unix` clean: zero errors, zero warnings.
With -Wsign-compare -Wstrict-aliasing=2 -Wcast-align: zero warnings.
audit_determinism.py: 0 issues.
Output binary 4,388,408 bytes (was 4,388,576 from upstream
004c147; -168 bytes from dead-code removal).
FCE Ultra mappers modified
FCEU "mappers modified" is an unofficial build of FCEU Ultra by CaH4e3, which supports a lot of new mappers including some obscure mappers such as one for unlicensed NES ROM's.
Sequential targets Light Guns support added
Support for Sequential targets Light Guns has been added. "Gun Aux A" serves as light sensor logic input.