.clang-tidy

# clang-tidy config for virtualjaguar-libretro.
#
# Curated check list aimed at catching real bugs in emulator C code
# without flooding the diff with style-preference noise.  See the
# CI workflow `clang-tidy` job for how this is invoked (only on
# PR-changed files).
#
# Disabled checks rationale below each `-` entry.

Checks: >
  bugprone-*,
  clang-analyzer-*,
  readability-inconsistent-declaration-parameter-name,
  readability-misleading-indentation,
  readability-redundant-control-flow,
  misc-redundant-expression,
  -bugprone-easily-swappable-parameters,
  -bugprone-narrowing-conversions,
  -bugprone-implicit-widening-of-multiplication-result,
  -bugprone-reserved-identifier,
  -bugprone-assignment-in-if-condition,
  -bugprone-macro-parentheses,
  -bugprone-signed-char-misuse,
  -bugprone-suspicious-include,
  -bugprone-switch-missing-default-case,
  -bugprone-branch-clone,
  -bugprone-incorrect-roundings,
  -bugprone-multi-level-implicit-pointer-conversion,
  -clang-analyzer-deadcode.DeadStores,
  -clang-analyzer-optin.performance.Padding,
  -clang-analyzer-optin.portability.UnixAPI,
  -clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling,
  -clang-analyzer-valist.Uninitialized

# Don't promote to errors yet -- the workflow itself decides via
# --warnings-as-errors / continue-on-error.
WarningsAsErrors: ''

# Apply checks to in-tree headers but skip vendored / generated.
HeaderFilterRegex: '^(src/(core|tom|jerry|cd)|libretro\.c).*'

# Don't run clang-format inline (we have a separate clang-format job).
FormatStyle: none

# Disabled-check rationale:
# - easily-swappable-parameters: emulator hot paths take many same-typed args.
# - narrowing-conversions / implicit-widening: register byte ops trip these constantly.
# - reserved-identifier: __LIBRETRO__ and UAE __regs/__pads use reserved names by design.
# - assignment-in-if-condition: idiomatic in dispatch loops.
# - macro-parentheses: misfires on GET16/SET32 byte-swap macros.
# - signed-char-misuse: ROM byte buffers commonly use signed char.
# - suspicious-include: project includes .c files in a couple of dispatch headers.
# - switch-missing-default-case: cosmetic; switches on bit-field decode patterns
#   commonly omit default because all valid bit values are handled.
# - incorrect-roundings: src/core/event.h's USEC_TO_RISC_CYCLES /
#   USEC_TO_M68K_CYCLES use the (double + 0.5) integer-cast idiom for
#   cycle conversion.  lround() is C99 (we're C89/GNU89), and the
#   inputs are non-negative so the idiom is correct here.
# - multi-level-implicit-pointer-conversion: dlsym() returns void*
#   that test harnesses cast directly to function pointers / data
#   pointer-to-pointer; canonical idiom in the libretro dlsym pattern.
# - branch-clone: register-decode if-chains in src/cd/cdrom.c and src/tom/tom.c
#   intentionally write the same value for several adjacent register addresses
#   to make the address->effect mapping legible.  Real bug clones are caught
#   by code review, not this check.
# - deadcode.DeadStores: blitter / OP / register-decode functions self-doc-init
#   locals that are read via macros (BCOMPEN, DSTA2, ...) clang-tidy can't see
#   the linkage for.  Removing these inits would introduce real bugs.
# - DeprecatedOrUnsafeBufferHandling: MSVC-flavored noise about strcpy/sprintf.
# - optin.performance.Padding: upstream UAE/Virtual Jaguar struct layouts
#   inherited from 1990s emulator code; reordering for tighter packing risks
#   silent layout breaks in save-state / dlsym paths and isn't free perf.
# - optin.portability.UnixAPI: false positive on libretro_core_options.h calloc.
# - valist.Uninitialized: false-positive prone on our log macros.