#!/bin/sh
set -eu

: "${PACKAGE_VERSION:?}"

: "${CPU_AS:?}" "${CPU_LD:?}" "${CPU_RUN:?}" "${CPU_READELF:?}"
: "${CPU_AR:?}" "${CPU_NM:?}" "${CPU_STRIP:?}" "${STRIP_FIXTURE:?}"

TMP=${TMPDIR:-/tmp}/libmcpu-strip-$$
mkdir -p "$TMP"
trap 'rm -rf "$TMP"' EXIT HUP INT TERM

cat > "$TMP/main.s" <<'EOS'
.global _life
.text
_start_life:
        LDI     r64@0x00000, 42
        LDI     r32@0x00030, 0
        EXIT    r32@0x00030
EOS


cat > "$TMP/dynamic-main.s" <<'EOS'
.global _life
.extern add_one
.text
_start_life:
        LDI     r64@0x00000, 41
        CALL    add_one
        MOV     r64@0x00018, r64@0x00000
        LDI     r32@0x00030, 0
        EXIT    r32@0x00030
EOS

cat > "$TMP/add-one.s" <<'EOS'
.global add_one
.text
add_one:
        LDI     r64@0x00008, 1
        IADD    r64@0x00000, r64@0x00000, r64@0x00008
        RET
EOS

"$CPU_AS" -o "$TMP/main.o" "$TMP/main.s"
"$CPU_AS" -o "$TMP/add-one.o" "$TMP/add-one.s"
"$CPU_AS" -o "$TMP/dynamic-main.o" "$TMP/dynamic-main.s"
"$CPU_LD" --stack-size=4096 --no-heap -o "$TMP/main" "$TMP/main.o"
"$CPU_LD" --dynamic --stack-size=4096 --no-heap -o "$TMP/dynamic-main" "$TMP/dynamic-main.o"
"$CPU_LD" --shared --soname=libadd.so.1 -o "$TMP/libadd.so" "$TMP/add-one.o"
"$CPU_AR" rcs "$TMP/libadd.a" "$TMP/add-one.o"

# ET_REL .symtab/.strtab are link semantics and are preserved byte-for-byte.
"$CPU_STRIP" -o "$TMP/main.stripped.o" "$TMP/main.o"
cmp "$TMP/main.o" "$TMP/main.stripped.o"
"$CPU_READELF" -s "$TMP/main.stripped.o" | grep -q '_life'

# Current final writers already emit no ordinary .symtab, so these are no-ops.
"$CPU_STRIP" -o "$TMP/main.clean" "$TMP/main"
cmp "$TMP/main" "$TMP/main.clean"
"$CPU_STRIP" -o "$TMP/libadd.clean.so" "$TMP/libadd.so"
cmp "$TMP/libadd.so" "$TMP/libadd.clean.so"
"$CPU_READELF" -S "$TMP/libadd.clean.so" > "$TMP/libadd.sections"
grep -q '\.dynsym' "$TMP/libadd.sections"
grep -q '\.dynstr' "$TMP/libadd.sections"
grep -q '\.mcpu.target' "$TMP/libadd.sections"

# The same removal policy on ET_DYN must preserve dynamic symbols/relocations.
"$STRIP_FIXTURE" "$TMP/libadd.so" "$TMP/libadd.with-sym.so"
"$CPU_READELF" -S -s "$TMP/libadd.with-sym.so" > "$TMP/dyn-before.txt"
grep -q '\.symtab' "$TMP/dyn-before.txt"
"$CPU_STRIP" -o "$TMP/libadd.really-stripped.so" "$TMP/libadd.with-sym.so"
"$CPU_READELF" -S -s "$TMP/libadd.really-stripped.so" > "$TMP/dyn-after.txt"
if grep -q '\.symtab' "$TMP/dyn-after.txt"; then
  echo "ordinary ET_DYN .symtab survived mcpu-strip" >&2
  exit 1
fi
grep -q '\.dynsym' "$TMP/dyn-after.txt"
grep -q '\.dynstr' "$TMP/dyn-after.txt"
test "`MCPU_LD_PRELOAD= "$CPU_RUN" --ldpreload="$TMP/libadd.really-stripped.so" --int-reg=r64@0x00018 "$TMP/dynamic-main"`" = 42

# Deterministic ET_REL archives keep their members and symbol index intact.
"$CPU_STRIP" -o "$TMP/libadd.clean.a" "$TMP/libadd.a"
cmp "$TMP/libadd.a" "$TMP/libadd.clean.a"
"$CPU_NM" -A "$TMP/libadd.clean.a" | grep -q 'add_one'

# Add a conventional non-runtime .symtab/.strtab to a valid ET_EXEC fixture.
# mcpu-strip must remove them, shrink the file and leave execution untouched.
"$STRIP_FIXTURE" "$TMP/main" "$TMP/main.with-sym"
chmod 755 "$TMP/main.with-sym"
"$CPU_READELF" -S -s "$TMP/main.with-sym" > "$TMP/before.txt"
grep -q '\.symtab' "$TMP/before.txt"
grep -q 'fixture_symbol' "$TMP/before.txt"
before=`wc -c < "$TMP/main.with-sym"`

"$CPU_STRIP" -o "$TMP/main.really-stripped" "$TMP/main.with-sym"
"$CPU_READELF" -S -s "$TMP/main.really-stripped" > "$TMP/after.txt"
if grep -q '\.symtab' "$TMP/after.txt"; then
  echo "ordinary .symtab survived mcpu-strip" >&2
  exit 1
fi
if grep -q 'fixture_symbol' "$TMP/after.txt"; then
  echo "ordinary symbol string survived mcpu-strip" >&2
  exit 1
fi
after=`wc -c < "$TMP/main.really-stripped"`
test "$after" -lt "$before"
test "`stat -c %a "$TMP/main.really-stripped"`" = 755
test "`"$CPU_RUN" --int-reg=r64@0x00000 "$TMP/main.really-stripped"`" = 42

# In-place replacement is atomic from the caller's point of view and keeps mode.
cp "$TMP/main.with-sym" "$TMP/main.inplace"
chmod 751 "$TMP/main.inplace"
"$CPU_STRIP" "$TMP/main.inplace"
test "`stat -c %a "$TMP/main.inplace"`" = 751
test "`"$CPU_RUN" --int-reg=r64@0x00000 "$TMP/main.inplace"`" = 42
if "$CPU_READELF" -S "$TMP/main.inplace" | grep -q '\.symtab'; then
  echo "in-place strip left .symtab" >&2
  exit 1
fi

"$CPU_STRIP" --help | grep -q -- '--output=FILE'
"$CPU_STRIP" --version | grep -Fq "$PACKAGE_VERSION"

if "$CPU_STRIP" "$TMP/main" "$TMP/main.clean" >/dev/null 2>&1; then
  echo "mcpu-strip unexpectedly accepted multiple input files" >&2
  exit 1
fi

exit 0