# No BST-TIMEOUT marker, deliberately: measured at 14 s for 78 cases on the
# BRINTOS-393 build (2026-08-08), which fits the bare 60 s default with ~4x
# headroom and the 300 s the gates and the nightly pass with ~21x. A marker is
# for a suite too heavy for the default; declaring one here would state
# something untrue about this suite's weight.
. "$BST_LIB"

# liblightmodbus 2.0.2 (git 59d2b405) -- "a lightweight, highly configurable,
# platform-independent Modbus RTU library" (meta-oe recipes-extended). What
# ships is /usr/lib/liblightmodbus.a and the lightmodbus/ header tree. There is
# no program, no pkg-config file and no shared object.
#
# ---------------------------------------------------------------------------
# WHY THIS SUITE RUNS A PROBE
#
# liblightmodbus installs NO PROGRAM, and its upstream test/test.c is a COVERAGE
# driver rather than an oracle -- CMakeLists only builds it under COVERAGE_TEST,
# it needs the `examine` addon no release build compiles, and it asserts almost
# nothing about the bytes. So there is nothing on the target's command line that
# could exercise this library, and a suite that only checked the payload's shape
# would go green on a library that answers wrongly. That is the BRINTOS-217
# lesson: oniguruma compiled and packaged perfectly and then handed every caller
# wrong offsets.
#
# data/liblightmodbus-probe (src/liblightmodbus_probe.c) is the consumer that
# closes the gap. It is cross-linked with wasmcc-glibc against THE VERY ARCHIVE
# THAT SHIPS, and it drives the library the way a Modbus application does:
# builds RTU frames for all nine function codes, hands them to an in-process
# slave, parses the answers back, and prints the exact wire bytes at every step.
#
# ---------------------------------------------------------------------------
# WHY THE WIRE BYTES ARE THE ASSERTION, AND NOT "IT RETURNED 0"
#
# Modbus puts its 16-bit fields on the wire BIG-endian and the trailing CRC
# LITTLE-endian, so no single byte order is right for a whole frame.
# liblightmodbus resolves that with modbusMatchEndian(), whose direction is
# decided by a macro CMake bakes into libconf.h at configure time from
# TEST_BIG_ENDIAN. A cross build that mis-detects this arm produces a library
# that compiles, links, packages, and puts every register index and count on the
# wire byte-swapped while returning MODBUS_ERROR_OK throughout -- and an
# in-process round trip would still agree with itself, because both halves are
# wrong the same way. Only comparing the bytes to a known-good build catches it,
# which is why liblightmodbus/wire-index-big-endian and the frame comparisons
# below exist at all.
#
# ---------------------------------------------------------------------------
# THE ORACLE IS A NATIVE x86_64 CONTROL, PLUS THE SPEC ITSELF
#
# data/liblightmodbus-native.txt is the same probe's output against a build of
# the IDENTICAL commit on x86_64 (src/liblightmodbus_mknative.sh). meta-oe's
# recipe carries one patch, Khem Raj's GNUInstallDirs change, which moves where
# the archive installs and touches no code -- so "the identical source" is
# literal. Every LMB- line must match byte for byte; the three values that
# legitimately differ (pointer width, the two struct sizes that contain
# pointers, and the git-describe string CMake bakes in) are printed LMBV-, kept
# out of the control, and reported separately.
#
# A control alone would not be enough. It is generated from a build, so a
# control regenerated against a broken build could quietly move the expected
# value with it. The ANCHORED block at the end therefore re-asserts six values
# as LITERALS taken from the Modbus Application Protocol specification's own
# worked examples -- the FC22 read-modify-write result, the FC15 example frame,
# the published CRC of the spec's FC03 request -- so those cannot move whatever
# any build says.

D=${TMPDIR:-/tmp}/bst-lmb.$$
rm -rf "$D"; mkdir -p "$D"

# has <id> <needle> <haystack>
#
# A red carries THE LINE THE PROBE ACTUALLY PRINTED, not just the needle that
# was missing -- every probe case prints its measured value, so a failure is
# self-describing and does not cost a second guest boot to diagnose.
has() {
  case "$3" in
    *"$2"*) bst_ok "$1" ;;
    *)
      _n=${2%% *}
      _got=$(printf '%s\n' "$3" | grep "^$_n " | head -1)
      bst_notok "$1" "${_got:-no $_n line}" ;;
  esac
}

# lmb_get <LMB-key> -- the value the probe printed for one case
lmb_get() { printf '%s\n' "$out" | grep "^$1 " | head -1 | cut -d' ' -f2-; }

# --- payload shape ------------------------------------------------------------
# The archive, the umbrella header, the four function-code header directories
# and the CMake-generated libconf.h. A missing libconf.h is the interesting one:
# it is not in the git tree at all -- configure_file() writes it -- so its
# absence would mean the port shipped headers that cannot even be included.
inv=""
for f in /usr/lib/liblightmodbus.a \
         /usr/include/lightmodbus/lightmodbus.h \
         /usr/include/lightmodbus/libconf.h \
         /usr/include/lightmodbus/master.h \
         /usr/include/lightmodbus/slave.h \
         /usr/include/lightmodbus/parser.h \
         /usr/include/lightmodbus/master/mbregs.h \
         /usr/include/lightmodbus/master/mbcoils.h \
         /usr/include/lightmodbus/slave/sregs.h \
         /usr/include/lightmodbus/slave/scoils.h; do
  [ -e "$f" ] || inv="$inv $f"
done
if [ -n "$inv" ]; then bst_notok liblightmodbus/payload "absent:$inv"; else bst_ok liblightmodbus/payload; fi

# The standing static-only invariant, on an arm whose linker cannot make a
# shared object at all.
so=$(find /usr/lib /lib -name 'liblightmodbus*.so*' 2>/dev/null | head -3)
if [ -n "$so" ]; then bst_notok liblightmodbus/no-shared-object "found: $so"; else bst_ok liblightmodbus/no-shared-object; fi

# --- the shipped configuration, read off the header rather than off the probe -
# This is deliberately independent evidence: the probe reports what the ARCHIVE
# was compiled with, and this reports what a CONSUMER compiling against the
# shipped headers would get. They can disagree -- a header tree from one build
# beside an archive from another -- and that disagreement is invisible to any
# test that only asks one of them.
conf=/usr/include/lightmodbus/libconf.h
if [ -r "$conf" ]; then
  check_out liblightmodbus/header-endianness "define LIGHTMODBUS_LITTLE_ENDIAN" cat "$conf"
  check_out liblightmodbus/header-version    'define LIGHTMODBUS_VERSION "2.0"' cat "$conf"
  check_out liblightmodbus/header-master     "define LIGHTMODBUS_MASTER_BASE"   cat "$conf"
  check_out liblightmodbus/header-slave      "define LIGHTMODBUS_SLAVE_BASE"    cat "$conf"
  # A big-endian define on this arm would be the corruption described in the
  # header comment, so it is asserted as an absence, not merely as "the little
  # one is there" -- both can be defined, and lightmodbus.h #errors if they are.
  if grep -q 'define LIGHTMODBUS_BIG_ENDIAN' "$conf" 2>/dev/null; then
    bst_notok liblightmodbus/header-not-big-endian "libconf.h defines LIGHTMODBUS_BIG_ENDIAN"
  else
    bst_ok liblightmodbus/header-not-big-endian
  fi
else
  bst_notok liblightmodbus/header-readable "cannot read $conf"
fi

# --- the probe ----------------------------------------------------------------
# do_install ships data/ at 0644 and the rootfs is read-only at browser runtime,
# so the payload arrives non-executable and must be staged somewhere writable.
# test -f on the shipped file, never test -x: asserting -x on $BST_DATA passes
# against a hand-placed copy and fails against every image that ever built it.
probe=$D/liblightmodbus-probe
if [ ! -f "$BST_DATA/liblightmodbus-probe" ]; then
  bst_notok liblightmodbus/probe-shipped "data/liblightmodbus-probe not installed"
elif cp "$BST_DATA/liblightmodbus-probe" "$probe" 2>/dev/null && chmod +x "$probe" 2>/dev/null; then
  bst_ok liblightmodbus/probe-shipped
  out=$("$probe" 2>&1)

  has liblightmodbus/probe-ran "LMB-probe-end OK" "$out"

  # --- build configuration the archive was compiled with ---------------------
  has liblightmodbus/version     "LMB-version 2.0"        "$out"
  has liblightmodbus/endianness  "LMB-endianness little"  "$out"
  has liblightmodbus/modules \
      "LMB-modules SLAVE_BASE MASTER_BASE F01S F02S F03S F04S F05S F06S F15S F16S F22S F01M F02M F03M F04M F05M F06M F15M F16M F22M SLAVE_USER_FUNCTIONS MASTER_USER_FUNCTIONS" \
      "$out"
  # The parser union IS the frame buffer, and 256 is the RTU maximum the
  # protocol fixes -- it carries no pointer, so it is comparable across arms.
  has liblightmodbus/parser-size "LMB-sizeof-parser 256"  "$out"

  # --- pure arithmetic: the pieces every frame is built out of ---------------
  has liblightmodbus/bits-to-bytes "LMB-bits-to-bytes 0:0 1:1 7:1 8:1 9:2 16:2 17:3 2000:250" "$out"
  has liblightmodbus/swap-endian   "LMB-swap-endian 3412 FF00 ADDE" "$out"
  has liblightmodbus/match-endian  "LMB-match-endian 3412"          "$out"

  # --- CRC ------------------------------------------------------------------
  has liblightmodbus/crc-empty     "LMB-crc-empty FFFF"    "$out"
  has liblightmodbus/crc-ramp-fold "LMB-crc-ramp-fold"     "$out"

  # --- the bit-array helpers a coil response is decoded with ----------------
  has liblightmodbus/mask-write    "LMB-mask-write-pattern 499224"                   "$out"
  has liblightmodbus/mask-read     "LMB-mask-read-pattern 100100100100100100100100" "$out"
  has liblightmodbus/mask-oob      "LMB-mask-read-oob 255 255"                       "$out"

  # --- request building, all nine function codes ----------------------------
  for f in 01 02 03 04 05 06 15 16 22; do
    has "liblightmodbus/build-fc$f" "LMB-req$f " "$out"
  done
  has liblightmodbus/build-refuses-count0   "LMB-req03-count0-rc 6 builderr=3"    "$out"
  has liblightmodbus/build-refuses-count126 "LMB-req03-count126-rc 6 builderr=3"  "$out"
  has liblightmodbus/build-refuses-2001coils "LMB-req01-count2001-rc 6 builderr=3" "$out"

  # --- round trips: every function code driven master -> slave -> master ----
  for f in 01 02 03 04 05 06 15 16 22; do
    has "liblightmodbus/roundtrip-fc$f" "LMB-rt$f-rc serr=0 merr=0 sparse=0 mparse=0" "$out"
  done
  has liblightmodbus/read-holding  "LMB-rt03-vals 4096 4097 4098 4099"          "$out"
  has liblightmodbus/read-input    "LMB-rt04-vals 40962 40963 40964"            "$out"
  has liblightmodbus/read-coils    "LMB-rt01-vals 1 0 1 0 0 1 0 1 1 0 1 0 0 1 0 1" "$out"
  has liblightmodbus/read-dins     "LMB-rt02-vals 1 1 0 0 0 0 1 1 1 1 0 0"      "$out"
  has liblightmodbus/write-single-reg   "LMB-rt06-slave-reg3 17185"             "$out"
  has liblightmodbus/write-multi-regs   "LMB-rt16-slave-regs 273 546 819"       "$out"
  has liblightmodbus/write-single-coil  "LMB-rt05-slave-coils A7A5A5A5"         "$out"
  has liblightmodbus/write-multi-coils  "LMB-rt15-slave-coils A7CDA5A5"         "$out"

  # --- the error paths a bus application actually depends on ----------------
  has liblightmodbus/excep-illegal-address "LMB-ex-range-excep addr=27 fn=131 code=2" "$out"
  has liblightmodbus/excep-illegal-function "LMB-ex-fun-excep addr=27 fn=193 code=1"  "$out"
  has liblightmodbus/reject-bad-crc        "LMB-ex-crc-rc serr=5 merr=5 sparse=1"     "$out"
  has liblightmodbus/ignore-other-slave    "LMB-ex-addr-rc serr=0 merr=5 sparse=0"    "$out"
  has liblightmodbus/broadcast-applied     "LMB-ex-bcast-slave-reg5 7777"             "$out"
  has liblightmodbus/broadcast-unanswered  "LMB-ex-bcast-resp -"                      "$out"
  has liblightmodbus/write-protection      "LMB-ex-nowrite-excep addr=27 fn=134 code=4" "$out"
  has liblightmodbus/write-protection-held "LMB-ex-nowrite-slave-reg6 1006"           "$out"
  has liblightmodbus/short-frame           "LMB-ex-short-rc 5 parse=2"                "$out"
  has liblightmodbus/null-refused \
      "LMB-ex-null slaveinit=4 slaveparse=4 slaveend=4 masterinit=4 masterparse=4 masterend=4" "$out"
  has liblightmodbus/slave-addr0-refused   "LMB-ex-slave-addr0 3"                     "$out"
  has liblightmodbus/mismatch-value        "LMB-ex-mism-value 5 parse=16"             "$out"
  has liblightmodbus/mismatch-index        "LMB-ex-mism-index 5 parse=14"             "$out"
  has liblightmodbus/mismatch-address      "LMB-ex-mism-addr 5 parse=13"              "$out"
  has liblightmodbus/mismatch-function     "LMB-ex-mism-fun 5 parse=12"               "$out"

  # --- allocator churn -------------------------------------------------------
  # Every exchange allocates and frees the request, the response and the
  # master's data buffer. On a guest whose whole heap is a linear-memory arena
  # inside a browser tab, that is the part of this port most likely to behave
  # differently -- and a leak or a use-after-free shows up as wrong data long
  # before it shows up as a crash, which is why the probe re-checks the answers
  # on every one of the 500 cycles rather than only at the end.
  has liblightmodbus/alloc-churn   "LMB-churn cycles=500 bad=0"     "$out"
  has liblightmodbus/initend-churn "LMB-initend-churn cycles=200 OK" "$out"

  # --- byte-identity against the x86_64 control ------------------------------
  # No exclusions: the probe already routes everything that may legitimately
  # differ to LMBV-, so any LMB- difference at all is a finding.
  ctl=$BST_DATA/liblightmodbus-native.txt
  gotf=$D/got.txt
  ctlf=$D/ctl.txt
  printf '%s\n' "$out" | grep '^LMB-' > "$gotf"
  grep '^LMB-' "$ctl" 2>/dev/null > "$ctlf"
  if [ ! -s "$ctlf" ]; then
    bst_notok liblightmodbus/native-byte-identical "control absent or empty: $ctl"
  elif cmp -s "$ctlf" "$gotf"; then
    bst_ok liblightmodbus/native-byte-identical
  else
    bst_notok liblightmodbus/native-byte-identical \
      "first diff: $(diff "$ctlf" "$gotf" 2>/dev/null | sed -n '2,3p' | tr '\n' ' ' | cut -c1-90)"
  fi

  # --- reported, never compared ---------------------------------------------
  # The values that legitimately differ between a 64-bit host and this 32-bit
  # arm. Named so a reader can see them, asserted only for presence.
  for k in pointer-width sizeof-master sizeof-slave git-version; do
    if printf '%s\n' "$out" | grep -q "^LMBV-$k "; then
      bst_ok "liblightmodbus/reported-$k"
    else
      bst_notok "liblightmodbus/reported-$k" "no LMBV-$k line"
    fi
  done

  # --- ANCHORED: the Modbus specification's own numbers ----------------------
  # These duplicate comparisons above ON PURPOSE. Everything else here is
  # scored against a control that is itself generated from a build, so a
  # control regenerated against a broken build could move the expected value
  # with it. These six cannot move: they are literals out of the Modbus
  # Application Protocol specification's worked examples and out of the RTU
  # framing rules, and they are exactly the values a wrong endianness
  # configuration changes.
  #
  # Big-endian on the wire: request 03 built for index 0x1234 must carry 12 34
  # in that order, and its count 0x0002 as 00 02.
  check_eq liblightmodbus/wire-index-big-endian 1234 "$(lmb_get LMB-req03-wire-index)"
  check_eq liblightmodbus/wire-count-big-endian 0002 "$(lmb_get LMB-req03-wire-count)"
  # ...while the CRC that follows goes out LITTLE-endian, which is why no single
  # byte order is right for a whole frame.
  check_eq liblightmodbus/wire-crc-little-endian 8287 "$(lmb_get LMB-req03-wire-crc)"
  # The published CRC of the specification's own FC03 request 11 03 006B 0003,
  # which the spec prints on the wire as 76 87.
  check_eq liblightmodbus/spec-crc-example 8776 "$(lmb_get LMB-crc-vec2)"
  # The specification's FC15 example: write 10 coils from 0x0013, values CD 01.
  check_eq liblightmodbus/spec-fc15-frame "1B0F0013000A02CD01C1AB len=11" "$(lmb_get LMB-req15)"
  # The specification's FC22 worked example: content 0x0012, And 0x00F2,
  # Or 0x0025 -> 0x0017. This is read-modify-write done by the slave on its own
  # memory, so it is the one anchor that proves the SLAVE side computed rather
  # than echoed.
  check_eq liblightmodbus/spec-fc22-result 0017 "$(lmb_get LMB-rt22-slave-reg4)"
else
  bst_notok liblightmodbus/probe-stage "cannot stage $BST_DATA/liblightmodbus-probe"
fi

rm -rf "$D"