#!/usr/bin/env bash
# Step 8: the thing the whole spike is really asking about -- ONE binary that
# is both a compiled Flan program and the OCaml compiler, with clang doing the
# final link.
#
# Everything before this proved a piece. This proves the shape: the Flan
# program's own main() is renamed out of the way, a C main() takes the main
# thread and runs the program there, and caml_startup happens on a side thread
# beside it. That is exactly item 11's inversion, built for real.
#
# It is NOT the merged architecture -- nothing is wired up, the compiler and the
# program do not talk. It is a link and a size and a startup number.
set -u
here=$(cd "$(dirname "$0")" && pwd)
root=$(cd "$here/../.." && pwd)
src=${1:-test/programs/edn.flan}
cd "$root" || exit 1
out=$(mktemp -d); trap 'rm -rf "$out"' EXIT

FLAN=_build/default/bin/main.exe
OCAMLLIB=$(ocamlopt -where)
SYSLIBS="-lm -lpthread -ldl -lzstd"

echo "program: $src"

# 1. The Flan program, as it is built today, for the baseline sizes.
"$FLAN" build "$src" -o "$out/rel" || exit 1
"$FLAN" build "$src" --dev -o "$out/dev" || exit 1

# 2. The same program as an object, with its main renamed so a C main can own
#    the process. Emit writes @main literally; sed is enough to move it.
"$FLAN" emit "$src" --dev > "$out/prog.ll" || exit 1
sed -i 's/define i32 @main(/define i32 @flan_program_main(/' "$out/prog.ll"
grep -q 'define i32 @flan_program_main(' "$out/prog.ll" || {
  echo "could not find @main in the emitted IR -- adjust the rename"; exit 1; }
clang -c -x ir "$out/prog.ll" -o "$out/prog.o" || exit 1

# 3. The runtime the program needs, and the agent beside it.
clang -c -O2 runtime/flan_rt.c  -o "$out/rt.o"  || exit 1
clang -c -O2 runtime/flan_dev.c -o "$out/dev.o" || exit 1
clang -c -O2 vendor/agent/flan_agent.c -o "$out/ag.o" || exit 1

# 4. The whole OCaml compiler as one object.
ocamlfind ocamlopt -thread -package unix,threads.posix -linkpkg \
  -output-complete-obj \
  -I "$root/_build/default/lib/.flan.objs/byte" \
  -I "$root/_build/default/lib/.flan.objs/native" \
  -o "$out/compiler.o" "$root/_build/default/lib/flan.cmxa" \
  "$here/thread_ml.ml" || exit 1

# 5. One link. clang, as the project already does it.
clang -I"$OCAMLLIB" "$here/merged_main.c" "$out/prog.o" "$out/rt.o" "$out/dev.o" \
  "$out/ag.o" "$out/compiler.o" -o "$out/merged" $SYSLIBS || exit 1

echo
echo "sizes:"
for f in rel dev merged; do
  printf '  %-30s %9d bytes\n' "$f" "$(stat -c%s "$out/$f")"
done
printf '  %-30s %9d bytes\n' "what the compiler adds to a dev build" \
  "$(( $(stat -c%s "$out/merged") - $(stat -c%s "$out/dev") ))"

echo
echo "running the merged binary:"
"$out/merged" "$src"
echo "exit: $?"