#!/bin/sh -e

# This package mimics the download process of rust's 'x.py'
# bootstrap library to allow for the removal of the internet
# connection requirement per build.
{
    mkdir -p "${cache_dir:=build/cache/2021-06-17}"

    for tarball in *.tar.xz\?no-extract; do
        mv -f "$tarball" "$cache_dir/${tarball%%\?no-extract}"
    done
}

# Set shared linking as the default.
for f in \
    compiler/rustc_target/src/spec/linux_musl_base.rs \
    vendor/rustc-ap-rustc_target/src/spec/linux_musl_base.rs
do
    sed 's/\(crt_static_default = \)true/\1false/' "$f" > _
    mv -f _ "$f"
done

# Ignore checksums of files modified above.
sed 's/\("files":{\)[^}]*/\1/' \
    vendor/rustc-ap-rustc_target/.cargo-checksum.json > _
mv -f _ vendor/rustc-ap-rustc_target/.cargo-checksum.json

cat > config.toml <<EOF
[llvm]
link-shared = true

[build]
build     = "x86_64-unknown-linux-musl"
host      = [ "x86_64-unknown-linux-musl" ]
target    = [ "x86_64-unknown-linux-musl" ]

docs           = false
compiler-docs  = false
extended       = true
submodules     = false
python         = "python3"
locked-deps    = true
vendor         = true
tools          = ["cargo", "rls", "clippy", "rustfmt", "analysis", "src", "rust-demangler"]
sanitizers     = false
profiler       = false
full-bootstrap = false

[install]
prefix = "/usr"

[target.x86_64-unknown-linux-musl]
llvm-config = "/usr/bin/llvm-config"
crt-static  = false

[rust]
channel           = "stable"
rpath             = false
debuginfo-level   = 0
debug             = false
backtrace         = false
jemalloc          = false
debug-assertions  = false
codegen-tests     = false
codegen-units-std = 1
EOF

# Workaround to get Rust to build in llvm-only environments.
case $("$CC" -print-file-name=libunwind.so) in */*)
    printf 'llvm-libunwind = "system"\n' >> config.toml

    # libgcc_s.so is needed for Rust's bootstrap binaries, on llvm-only systems
    # this library does not exist. This hack creates it as alias to libunwind.
    {
        mkdir -p libgcc

        printf 'INPUT(-lunwind)\n' > \
            libgcc/libgcc_s.so

        ln -sf "$KISS_ROOT/usr/lib/libunwind.so.1" \
            libgcc/libgcc_s.so.1

        export \
            LD_LIBRARY_PATH="$PWD/libgcc:$LD_LIBRARY_PATH" \
            LIBRARY_PATH="$PWD/libgcc:$LIBRARY_PATH"
    }
esac

python3 ./x.py build -j "$(nproc)"
python3 ./x.py install

rm -rf \
    "$1/usr/lib/rustlib/src/" \
    "$1/usr/share/doc" \
    "$1/usr/share/zsh" \
    "$1/usr/lib/rustlib/uninstall.sh"