A cache-arduino8266 composite action mirrors cache-esp-idf (one key
resolver, dev-writes/PR-restores) and both jobs pin
ESPHOME_ARDUINO8266_PREFIX so YAML and Python agree on the path by
construction. esp32 provides the native_toolchain_module hook, so the
shared dispatcher never names a backend and the unclaimed-native raise
loses its esp-idf carve-out; the esp8266 decode and run_compile hooks
resolve through the same seam. run_compile resolves ccache once and
threads it to the generator, env, and idedata; the compdb rule names
follow the shared kinds; the pio-options warner inlines into the driver
and derives its consumed set from the core routing constant; the
per-toolchain CI narrowing shares one body; create_components_graph is
memoized per run; the decode rate-limit drops its math sentinel.
The build.ninja python variable goes through strip_win_long_path_prefix
like every other emitted binary path (the NSIS launcher's extended
prefix cannot be spawned by cmd.exe). Compile rules are named by the
shared source kinds directly, retiring the identity translation table
and its drift test. write_project takes the caller's resolved ccache,
get_flash_ld_path reads the InstalledPaths the ninja file linked
against instead of re-resolving the version, the board backstop checks
the one table it indexes with an honest comment, and cc/cxx/ar paths go
through the shared toolchain_tool accessor (gaining the Windows
suffix).
toolchain_tool owns the bin path and Windows suffix now; _BuildConfig's
knob and MMU fields are required since the only constructor always
passes both; the tests' set-flags-then-resolve idiom collapses into one
_resolve helper (12 sites).
toolchain_tool carries the bin/xtensa-lx106-elf-<name> pattern and the
Windows suffix that four call sites previously spelled out (only one of
which handled the suffix). ccache_env and get_build_env accept the
already-resolved ccache path so run_compile can resolve once instead of
paying the PATH scan and runnability probe three times per build.
NATIVE_ARDUINO_PIO_OPTIONS is the single list the routing reads; the
backend's ignored-option warning consumes it too, so honoring a new key
is one edit instead of two synchronized ones.
The dict-shorthand bundled preference ran after convert_libraries had
already resolved the dependency through the registry, so a real
{"Wire": "*"} manifest still fetched or failed on a registry Wire (the
mocked test hid it). LibraryBackend gains an optional provides hook the
walk consults for owner-less dependencies; the arduino backend answers
from the framework tree and the bundled copy is added after emit. A
real-converter test with a local library pins that the registry is
never touched. _emit also validates the manifest shape by name before
apply_extra_script dereferences it.
Published configs override it to reserve a filesystem region or correct
a board's assumed flash size; the routed value replaces the BOARDS
default, and a path is rejected since the name resolves via -L.
The routed override (published configs pin 160000000L for
timing-sensitive integrations) reaches -DF_CPU via a small _pio_option
reader; the default stays the audited 80 MHz all 45 boards ship.
Published configs override it to reserve a filesystem region
(SmartIntercom's eagle.flash.4m2m.ld) or to correct a board's assumed
flash size (2 MB ESP8285 plugs pinning eagle.flash.2m.ld); dropping it
changes the flash layout under them.
J. Nick Koston