#!/bin/sh
set -eu

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

TMP=${TMPDIR:-/tmp}/libmcpu-link-needed-$$
HOME="$TMP/home"
export HOME
mkdir -p "$HOME/.mcpu/etc" "$TMP/root/lib" "$TMP/first"
trap 'rm -rf "$TMP"' EXIT HUP INT TERM

cat > "$TMP/main.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

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

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

cat > "$TMP/bad.s" <<'EOS'
.global other
.text
other:
        RET
EOS

"$CPU_AS" -o "$TMP/main.o" "$TMP/main.s"
"$CPU_AS" -o "$TMP/good.o" "$TMP/good.s"
"$CPU_AS" -o "$TMP/alt.o" "$TMP/alt.s"
"$CPU_AS" -o "$TMP/bad.o" "$TMP/bad.s"

# The development link name is libfoo.so, but the ABI identity recorded in
# DT_NEEDED comes from the validated library SONAME.
"$CPU_LD" --shared --soname=libfoo.so.1 \
  -o "$TMP/root/lib/libfoo.so.1.2.3" "$TMP/good.o"
ln -s libfoo.so.1.2.3 "$TMP/root/lib/libfoo.so.1"
ln -s libfoo.so.1 "$TMP/root/lib/libfoo.so"

"$CPU_LD" --dynamic --stack-size=4096 --no-heap \
  -L"$TMP/root/lib" -lfoo -o "$TMP/main" "$TMP/main.o"
"$CPU_READELF" -d "$TMP/main" > "$TMP/main.dynamic"
grep -q 'NEEDED.*\[libfoo.so.1\]' "$TMP/main.dynamic"
[ "`grep -c 'NEEDED' "$TMP/main.dynamic"`" -eq 1 ]
if grep -q 'libfoo.so.1.2.3' "$TMP/main.dynamic"; then
  echo "DT_NEEDED unexpectedly contains physical library filename" >&2
  exit 1
fi

# The separated -l NAME spelling is equivalent.
"$CPU_LD" --dynamic --stack-size=4096 --no-heap \
  -L "$TMP/root/lib" -l foo -o "$TMP/main-separated" "$TMP/main.o"
"$CPU_READELF" -d "$TMP/main-separated" | grep -q 'NEEDED.*\[libfoo.so.1\]'

# Repeated requests resolving to the same SONAME produce one dependency.
"$CPU_LD" --dynamic --stack-size=4096 --no-heap \
  -L"$TMP/root/lib" -lfoo -lfoo -o "$TMP/main-duplicate" "$TMP/main.o"
"$CPU_READELF" -d "$TMP/main-duplicate" > "$TMP/main-duplicate.dynamic"
[ "`grep -c 'NEEDED' "$TMP/main-duplicate.dynamic"`" -eq 1 ]

# -L order is real link-name search order.  The selected object's SONAME,
# not the requested link name, is recorded.
"$CPU_LD" --shared --soname=libfoo-alt.so.7 \
  -o "$TMP/first/libfoo.so" "$TMP/alt.o"
"$CPU_LD" --dynamic --stack-size=4096 --no-heap \
  -L"$TMP/first" -L"$TMP/root/lib" -lfoo \
  -o "$TMP/main-first" "$TMP/main.o"
"$CPU_READELF" -d "$TMP/main-first" | grep -q 'NEEDED.*\[libfoo-alt.so.7\]'

# The configured system library tree is also used by -l.
cat > "$HOME/.mcpu/etc/mcpu-ld.conf" <<EOC
MCPU_LD_SYSTEM_LIBRARY_PATH = $TMP/root/lib;
EOC
"$CPU_LD" --dynamic --stack-size=4096 --no-heap \
  -lfoo -o "$TMP/main-config" "$TMP/main.o"
"$CPU_READELF" -d "$TMP/main-config" | grep -q 'NEEDED.*\[libfoo.so.1\]'

# A shared object may itself record a direct ABI-v3 dependency.
"$CPU_LD" --shared --soname=libchild.so.1 \
  -lfoo -o "$TMP/libchild.so.1.0.0" "$TMP/bad.o"
"$CPU_READELF" -d "$TMP/libchild.so.1.0.0" > "$TMP/child.dynamic"
grep -q 'SONAME.*\[libchild.so.1\]' "$TMP/child.dynamic"
grep -q 'NEEDED.*\[libfoo.so.1\]' "$TMP/child.dynamic"

# A named dependency must exist and must be a valid ABI-v3 ET_DYN object.
if "$CPU_LD" --dynamic --stack-size=4096 --no-heap \
     -L"$TMP/root/lib" -lmissing -o "$TMP/missing" "$TMP/main.o" \
     >/dev/null 2>&1; then
  echo "missing -l dependency unexpectedly linked" >&2
  exit 1
fi

cp "$TMP/main" "$TMP/root/lib/libexec.so"
if "$CPU_LD" --dynamic --stack-size=4096 --no-heap \
     -L"$TMP/root/lib" -lexec -o "$TMP/from-exec" "$TMP/main.o" \
     >/dev/null 2>&1; then
  echo "ET_EXEC unexpectedly accepted as -l provider" >&2
  exit 1
fi

# Existing file, valid shared object, wrong exports: link must fail before
# producing an executable.
"$CPU_LD" --shared --soname=libbad.so.1 \
  -o "$TMP/root/lib/libbad.so" "$TMP/bad.o"
rm -f "$TMP/no-provider"
if "$CPU_LD" --dynamic --stack-size=4096 --no-heap \
     -L"$TMP/root/lib" -lbad -o "$TMP/no-provider" "$TMP/main.o" \
     >"$TMP/no-provider.out" 2>"$TMP/no-provider.err"; then
  echo "library without required export unexpectedly linked" >&2
  exit 1
fi
grep -q 'undefined symbol not provided by linked libraries: foo' \
  "$TMP/no-provider.err"
[ ! -e "$TMP/no-provider" ]

# ABI-v1 -l searches only for a static archive.  This directory contains
# only libfoo.so, so the static link must fail instead of using ET_DYN.
if "$CPU_LD" -L"$TMP/root/lib" -lfoo -o "$TMP/static" "$TMP/main.o" \
     >/dev/null 2>&1; then
  echo "ABI-v1 unexpectedly selected a shared -l provider" >&2
  exit 1
fi

# 0.2.16 resolves the recorded SONAME at runtime through the same system
# library search policy.  No explicit --ldpreload is required.
[ "`"$CPU_RUN" --int-reg=r64@0x00018 "$TMP/main"`" = 42 ]

"$CPU_LD" --help 2>&1 | grep -q -- '-l <name>'

exit 0