#!/bin/sh
set -eu

: "${CPU_AS:?}" "${CPU_LD:?}" "${CPU_RUN:?}"

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

cat > "$TMP/main.s" <<'EOS'
.global _life
.global foo
.text
_start_life:
        LDI     r64@0x00000, 40
        CALL    foo
        MOV     r64@0x00018, r64@0x00000
        LDI     r32@0x00030, 0
        EXIT    r32@0x00030
foo:
        LDI     r64@0x00008, 1
        IADD    r64@0x00000, r64@0x00000, r64@0x00008
        RET
EOS

cat > "$TMP/a.s" <<'EOS'
.global foo
.text
foo:
        LDI     r64@0x00008, 2
        IADD    r64@0x00000, r64@0x00000, r64@0x00008
        RET
EOS

cat > "$TMP/b.s" <<'EOS'
.global foo
.text
foo:
        LDI     r64@0x00008, 3
        IADD    r64@0x00000, r64@0x00000, r64@0x00008
        RET
EOS

"$CPU_AS" -o "$TMP/main.o" "$TMP/main.s"
"$CPU_AS" -o "$TMP/a.o" "$TMP/a.s"
"$CPU_AS" -o "$TMP/b.o" "$TMP/b.s"
"$CPU_LD" --dynamic --stack-size=4096 --no-heap -o "$TMP/main" "$TMP/main.o"
"$CPU_LD" --shared --soname=liba.so.1 -o "$TMP/lib/liba.so.1" "$TMP/a.o"
"$CPU_LD" --shared --soname=libb.so.1 -o "$TMP/lib/libb.so.1" "$TMP/b.o"
ln -s liba.so.1 "$TMP/lib/liba.so"
ln -s libb.so.1 "$TMP/lib/libb.so"

# Empty environment is the normal no-preload baseline.
[ "`MCPU_LD_PRELOAD= "$CPU_RUN" --library-path="$TMP/lib" \
      --int-reg=r64@0x00018 "$TMP/main"`" = 41 ]

# Environment-only preload uses the same resolver and rightmost-wins ordering.
[ "`MCPU_LD_PRELOAD=liba.so "$CPU_RUN" --library-path="$TMP/lib" \
      --int-reg=r64@0x00018 "$TMP/main"`" = 42 ]
[ "`MCPU_LD_PRELOAD=liba.so:libb.so "$CPU_RUN" --library-path="$TMP/lib" \
      --int-reg=r64@0x00018 "$TMP/main"`" = 43 ]
[ "`MCPU_LD_PRELOAD=libb.so:liba.so "$CPU_RUN" --library-path="$TMP/lib" \
      --int-reg=r64@0x00018 "$TMP/main"`" = 42 ]

# Command-line preload entries are appended after environment entries, so the
# established rightmost-higher-priority rule makes command line stronger.
[ "`MCPU_LD_PRELOAD=liba.so "$CPU_RUN" --library-path="$TMP/lib" \
      --ldpreload=libb.so --int-reg=r64@0x00018 "$TMP/main"`" = 43 ]
[ "`MCPU_LD_PRELOAD=libb.so "$CPU_RUN" --library-path="$TMP/lib" \
      --ldpreload=liba.so --int-reg=r64@0x00018 "$TMP/main"`" = 42 ]
[ "`MCPU_LD_PRELOAD=liba.so:libb.so "$CPU_RUN" --library-path="$TMP/lib" \
      --ldpreload=libb.so:liba.so --int-reg=r64@0x00018 "$TMP/main"`" = 42 ]

# Environment preload is equivalent to --ldpreload for ABI compatibility: an
# ABI-v1 static executable must reject it just as it rejects the CLI option.
"$CPU_LD" --stack-size=4096 --no-heap -o "$TMP/static" "$TMP/main.o"
if MCPU_LD_PRELOAD="$TMP/lib/liba.so.1" "$CPU_RUN" "$TMP/static" \
     >/dev/null 2>"$TMP/static.err"; then
  echo "ABI-v1 executable unexpectedly accepted MCPU_LD_PRELOAD" >&2
  exit 1
fi
grep -q 'dynamic modules require' "$TMP/static.err"

# The environment preload is independent of configuration suppression.  An
# explicit pathname therefore still works under --no-config.
[ "`MCPU_LD_PRELOAD="$TMP/lib/liba.so.1" "$CPU_RUN" --no-config \
      --int-reg=r64@0x00018 "$TMP/main"`" = 42 ]

# Environment preload remains an explicit override above a normal dependency.
cat > "$TMP/import.s" <<'EOS'
.global _life
.extern foo
.text
_start_life:
        LDI     r64@0x00000, 40
        CALL    foo
        MOV     r64@0x00018, r64@0x00000
        LDI     r32@0x00030, 0
        EXIT    r32@0x00030
EOS
"$CPU_AS" -o "$TMP/import.o" "$TMP/import.s"
"$CPU_LD" --dynamic --stack-size=4096 --no-heap -L"$TMP/lib" -la \
  -o "$TMP/import" "$TMP/import.o"
[ "`MCPU_LD_PRELOAD=libb.so "$CPU_RUN" --library-path="$TMP/lib" \
      --int-reg=r64@0x00018 "$TMP/import"`" = 43 ]

# Invalid environment lists and missing names are hard errors.
if MCPU_LD_PRELOAD=liba.so::libb.so "$CPU_RUN" --library-path="$TMP/lib" \
     "$TMP/main" >/dev/null 2>"$TMP/bad-list.err"; then
  echo "malformed MCPU_LD_PRELOAD unexpectedly accepted" >&2
  exit 1
fi
grep -q 'MCPU_LD_PRELOAD' "$TMP/bad-list.err"

if MCPU_LD_PRELOAD=does-not-exist.so "$CPU_RUN" --library-path="$TMP/lib" \
     "$TMP/main" >/dev/null 2>"$TMP/missing.err"; then
  echo "missing MCPU_LD_PRELOAD library unexpectedly accepted" >&2
  exit 1
fi
grep -q 'MCPU_LD_PRELOAD' "$TMP/missing.err"

MCPU_LD_PRELOAD= "$CPU_RUN" --help 2>&1 | grep -q 'MCPU_LD_PRELOAD'

exit 0