GeoCoord's constructor unconditionally computed all five coordinate
representations (DMS, UTM, MGRS, OSGR, OLC) via setCoords(), even
though most callers only ever read one. The UTM conversion alone pulls
in a chain of libm trig functions (atan, __kernel_tan, __ieee754_acos,
__ieee754_pow, __kernel_rem_pio2/__ieee754_rem_pio2) that then have to
be linked in regardless of whether anything is ever displayed.
The only screen consumer (UIRenderer.cpp's GPS coordinate display)
already dispatches on a single configured format and reads exactly one
representation per call - never more than one. Compute DMS eagerly
(cheap, most commonly needed) and defer UTM/MGRS/OSGR/OLC to first
access via their own getters, tracked with per-representation mutable
dirty flags, so a caller that never touches a given representation
never pulls in its conversion code or the trig functions it needs.
On stm32wl, GeoCoord's heavy constructor is reached only through
NMEAWPL.cpp's NMEA/CalTopo serial export (GPS-gated, so wio-e5 only),
which only ever reads the DMS getters - so this recovers 8,288 bytes
flash there (of the 10,172-byte ceiling if the whole feature were cut)
with the feature fully intact and zero behavior change on any
platform.
Updated test_geocoord_extreme_coords_no_oob (the existing regression
test for a historical out-of-bounds crash in the UTM/MGRS conversion
on extreme lat/lon) to explicitly call each representation's getter,
since it previously relied on the constructor eagerly triggering all
four conversions - which this change intentionally defers. Verified:
full native test suite passes (586/586 test cases, including this one
under ASan), and rak4631 (nRF52, screen-equipped, where the
UTM/MGRS/OSGR/OLC getters are actually reachable) builds successfully.
Assisted-by: Claude Sonnet 5 <noreply@anthropic.com>
Signed-off-by: Andrew Yong <me@ndoo.sg>
Co-authored-by: Ben Meadors <benmmeadors@gmail.com>
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