Its entire code subseg is the -O0 run and the .c is stub-only, so this is the boot
precedent: a whole-object CC1FLAGS override, no splat change, no carve, and none of
the 18-P29 re-disassembly risk. Proven byte-neutral by a CLEAN per-binary rebuild —
build dirs deleted, re-extract, rebuild:
sha1 80731bac0ddd6b3e354f43b2c179582b12590752 == config/check.md_MAIN_011.sha
Landed with the coupling fix it requires, or the 21 would have stayed invisible.
Three tools decided -O0-ness from the subseg NAME ('_o0' in it, or 'boot'); this
object keeps its plain name, so match_one would have warned 'cannot bank' about
functions that now bank and the wave draw would have kept refusing to draw them. All
three now ask corpus.o0_subseg(), which derives the answer from the Makefile itself
(R33: a name is a convention, the Makefile is ground truth).
Verified end to end: match_one compiles md_MAIN_011 targets at -O0 with the
cannot-bank warning correctly gone, the wave draw emits cards for them, and
test_o0_detect still passes 167/167 coverage with 0 false positives.
--o0 has existed since P29 and NOTHING ever passed it: api_draft.match_one(), the
oracle every wave agent iterates against, builds a fixed argv without it. Every agent
handed an -O0 target was shown an -O2 compile of its own C and a mismatch on every
instruction — feedback that cannot converge, for a reason invisible in the diff, and
it hit even the 51 functions already sitting in -O0 objects.
match_one now decides from the target (R33), with two oracles because neither alone
is sufficient (R34): the -O0 frame-pointer prologue in the target's own bytes, OR the
subseg being an object the Makefile compiles -O0. boot/start.s is built -O0 with no
ordinary prologue; an -O0 function stranded in an -O2 subseg has the prologue but
cannot bank — and match_one now says so instead of letting an agent chase it.
The prologue scan is anchored at glabel, not the top of the file: two md_MAIN_011
.s files open with a migrated jump table / .asciz blob and a naive scan read table
words as the prologue.
tools/test_o0_detect.py: 14,400 .s scanned, 167/167 signature files covered, 0 false
positives outside -O0 objects, both rodata-first files detected.
Census correction in the design doc: the handoff's refutation of md_MAIN_003/011 is
itself wrong (16 and 21 -O0 functions, byte-verified), and the 311 '$fp mentions'
figure over-counts because $fp is $s8, allocatable at -O2. True population: 167
files, of which 116 / 14,148 ins are -O0 functions the build compiles -O2 — double
the atlas estimate, with x2/x3/x4 sibling replication.
Drew T