#!/bin/sh
# Per-object self-hosting gate.
#
# Build the V3 compiler as separate objects with the current M2, link
# stage2, use stage2 to build the same objects/link stage3, and compare
# every generated .ssa.  The compiler itself is built with the legacy
# 1-D open-array ABI (the same rule as bootstrap/fixpoint.sh).
#
# Usage: ./bootstrap/fixpoint-separate.sh
# Requires: compiler/M2 and tools/m2make/b_v3/M2make.
set -eu
ROOT="$(cd "$(dirname "$0")/.." && pwd)"
M2="${M2:-$ROOT/compiler/M2}"
M2MAKE="${M2MAKE:-$ROOT/tools/m2make/b_v3/M2make}"
SHIM="$ROOT/runtime/syslib/shim.c"
SRC="$ROOT/compiler/src/M2.mod"
TMP="${TMP:-$ROOT/.scratch/fixpoint-separate}"
FLAGS="-legacyopen1d"
INCS="-I $ROOT/runtime/syslib -I $ROOT/compiler/src -I $ROOT/lib/common"

[ -x "$M2" ] || { echo "missing $M2 (run compiler/build.sh)"; exit 1; }
[ -x "$M2MAKE" ] || { echo "missing $M2MAKE (run tools/m2make/build_m2.sh)"; exit 1; }

rm -rf "$TMP"
mkdir -p "$TMP/s2" "$TMP/s3"

build_stage() {
  bin="$1"; out="$2"; dir="$3"
  ( cd "$dir" && "$M2MAKE" --separate --m2flag "$FLAGS" \
      --m2bin "$bin" --shim "$SHIM" $INCS -o "$out" "$SRC" )
}

echo "=== separate stage2 (built by $M2) ==="
build_stage "$M2" "$TMP/s2/M2" "$TMP/s2"
echo "=== separate stage3 (built by stage2) ==="
build_stage "$TMP/s2/M2" "$TMP/s3/M2" "$TMP/s3"

# Compare the generated per-object IR; object files and executables can
# contain timestamps/build ids and are not the fixpoint contract.
fail=0
for f in "$TMP/s2/gen_ssa"/*.ssa; do
  b=$(basename "$f")
  if [ ! -f "$TMP/s3/gen_ssa/$b" ]; then
    echo "MISSING stage3 object: $b"; fail=1
  elif ! cmp -s "$f" "$TMP/s3/gen_ssa/$b"; then
    echo "DIFF: $b"; fail=1
  fi
done
for f in "$TMP/s3/gen_ssa"/*.ssa; do
  b=$(basename "$f")
  [ -f "$TMP/s2/gen_ssa/$b" ] || { echo "EXTRA stage3 object: $b"; fail=1; }
done

if [ "$fail" -ne 0 ]; then
  echo "SEPARATE FIXPOINT FAILED"
  exit 1
fi
echo "SEPARATE FIXPOINT OK: stage2 == stage3 ($(ls "$TMP/s2/gen_ssa"/*.ssa | wc -l) objects)"