#!/usr/bin/env bash
set -euo pipefail

root="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")/.." && pwd)"
nm_tool="${RISCV_PREFIX:-riscv64-unknown-elf-}nm"
readelf_tool="${RISCV_PREFIX:-riscv64-unknown-elf-}readelf"

symbol_value() {
  "$nm_tool" -n "$1" | awk -v wanted="$2" '$3 == wanted { print $1; exit }'
}

for task in \
  task01_libc_without_heap \
  task03_bounded_sbrk \
  task04_smalloc \
  task05_picolibc_malloc; do
  elf="$root/build/$task/prog.elf"
  start_hex="$(symbol_value "$elf" __heap_start)"
  end_hex="$(symbol_value "$elf" __heap_end)"
  stack_bottom_hex="$(symbol_value "$elf" __stack_bottom)"
  reset_hex="$(symbol_value "$elf" .reset_handler)"
  [[ -n "$start_hex" && -n "$end_hex" && -n "$stack_bottom_hex" ]]
  [[ "$reset_hex" == "80000040" ]]
  (( 16#$start_hex <= 16#$end_hex ))
  (( 16#$end_hex == 16#$stack_bottom_hex ))
  (( (16#$start_hex & 15) == 0 ))
  (( (16#$end_hex & 15) == 0 ))
  "$readelf_tool" -h "$elf" | grep -q 'Class:.*ELF32'
  if "$readelf_tool" -lW "$elf" | grep -Eq 'LOAD.*RWE'; then
    echo "FAIL $task: writable and executable LOAD segment" >&2
    exit 1
  fi
done

task05="$root/build/task05_picolibc_malloc/prog.elf"
for symbol in _sbrk sbrk malloc free __heap_start __heap_end; do
  [[ -n "$(symbol_value "$task05" "$symbol")" ]]
done

printf '%s\n' \
  'PASS linker: reset=0x80000040; bounded aligned heap; no RWX LOAD segment' \
  'PASS Task05 ELF: vendor _sbrk and picolibc sbrk coexist'