#! /bin/bash

# rustc-tiny  (for CMLFS-based systems) 
# Source: https://static.rust-lang.org/dist/rustc-1.74.0-src.tar.xz 
#
# $BUILD = Directory to temporarily install
# $PKGS  = Directory to store built packages
#
# DEPS
# Required:     cargo rustc-bootstrap libffi libxml2 curl cmake 
# Recommended:  NONE
# Optional:     patchelf

# Apply patches from Chimera Linux 
patch -Np1 -i ../patches/rust-1.74.0-chimera/0001-add-chimera-targets-always-dynamic-musl-static-pie.patch
patch -Np1 -i ../patches/rust-1.74.0-chimera/0002-remove-a-bunch-of-unused-junk.patch
patch -Np1 -i ../patches/rust-1.74.0-chimera/0003-move-debugger-scripts-to-usr-share-rust.patch 
patch -Np1 -i ../patches/rust-1.74.0-chimera/0004-fix-shebang-on-install-template.sh.patch 
patch -Np1 -i ../patches/rust-1.74.0-chimera/0005-get-rid-of-wrong-linkage.patch 
patch -Np1 -i ../patches/rust-1.74.0-chimera/0006-do-not-install-libunwind-source-removed.patch
patch -Np1 -i ../patches/rust-1.74.0-chimera/0007-fix-rustdoc-when-cross-compiling.patch
patch -Np1 -i ../patches/rust-1.74.0-chimera/0008-link-stage-2-tools-dynamically-to-libstd.patch
patch -Np1 -i ../patches/rust-1.74.0-chimera/0009-use-CBUILD_TARGET_SYSROOT-to-locate-llvm-when-cross-.patch
patch -Np1 -i ../patches/rust-1.74.0-chimera/0010-do-not-export-LD_LIBRARY_PATH.patch 
patch -Np1 -i ../patches/rust-1.74.0-chimera/0011-drop-latomic-on-riscv-and-elsewhere.patch 

# Set build variables
export OPENSSL_NO_VENDOR=1 RUST_BACKTRACE=1 
export BOOTSTRAP=0 
export RUSTFLAGS="" PKG_CONFIG_ALLOW_CROSS=1

# Set cargo variables
export HOST_CC="clang" HOST_CFLAGS="-O2" ZSTD_SYS_USE_PKG_CONFIG=1
export PCRE2_SYS_STATIC=0  LIBSSH2_SYS_USE_PKG_CONFIG=1
export LIBGIT2_NO_VENDOR=1 CARGO_BUILD_JOBS=2 CARGO_PROFILE_RELEASE_CODEGEN_UNITS=1
export PKG_CONFIG_ALLOW_CROSS=1 

# Using patches from Chimera Linux introduces required variables
# Not sure if omitting patch 0009 is a good idea. For now:
export CBUILD_TARGET_SYSROOT="/"

# May need to add new "target" spec
# compiler/rustc_target/src/spec/x86_64_unknown_linux_musl.rs
# compiler/rustc_target/src/spec/x86_64_pc_linux_musl.rs
# compiler/rustc_target/src/spec/x86_64_cmlfs_linux_musl.rs << preferred ?
#
# Host & build target specs are limited by the bootstrap rustc. To check:
# rustc --print target-list
#
# Add new target spec [for target] to
# compiler/rustc_target/src/spec/mod.rs
#
# To create "new target spec":
#cat > compiler/rustc_target/src/spec/x86_64_pc_linux_musl.rs << "EOF"
#use crate::spec::Target;
#
#pub fn target() -> Target {
#    let mut base = super::x86_64_unknown_linux_musl::target();
#
#    base.llvm_target = "x86_64-pc-linux-musl".into();
#    base.options.vendor = "pc".into();
#
#    base
#}
#EOF

# Add "new target spec" to list of "supported targets"
#sed -i '1275 i \    \("x86_64-pc-linux-musl", x86_64_pc_linux_musl), ' \
#	compiler/rustc_target/src/spec/mod.rs

# Don't use bundled llvm, not patched for musl
rm -rf src/llvm-project

# Clear vendor checksums 
for d in libc libc-0.2.138 libc-0.2.140 libc-0.2.146 
do
	sed -i 's/\("files":{\)[^}]*/\1/' vendor/$d/.cargo-checksum.json
done

# Compiling will invoke c++ instead of g++ or clang++
sudo ln -sv clang-15 /usr/bin/c++

# Configure scripts seem to always fail. Use a config.toml instead.
# Copy build config. Make sure target, host, and build are all set to x86_64-unknown-linux-musl
cp -v ../files/config.toml.rustc-tiny config.toml

# Since dist build fails wtih bootstrap, just build up to stage2 rust standard 
# library & compiler:
env -u $PKGCONFIG -- python3 ./x.py build --stage 2 library -v --jobs 2
# rustc and 'core std library' will be built in:
# build/x86_64-unknown-linux-musl/stage2
# No extra tools built. Just the minimum to build other projects like librsvg and firefox

# Copy over to staging area
sudo mkdir -pv $BUILD/opt/rustc-1.74.0/{bin,lib}
sudo mkdir -pv $BUILD/opt/rustc-1.74.0/lib/rustlib/x86_64-unknown-linux-musl/lib
sudo cp -a build/x86_64-unknown-linux-musl/stage2/bin/rustc \
	   $BUILD/opt/rustc-1.74.0/bin/
sudo cp -a build/x86_64-unknown-linux-musl/stage2/lib/*.so \
	   $BUILD/opt/rustc-1.74.0/lib/
sudo cp -a build/x86_64-unknown-linux-musl/stage2/lib/rustlib/x86_64-unknown-linux-musl/lib/*.rlib \
	   $BUILD/opt/rustc-1.74.0/lib/rustlib/x86_64-unknown-linux-musl/lib/

sudo ln -sv rustc-1.74.0 $BUILD/opt/rustc 

# Set runtime path
sudo patchelf --set-rpath /opt/rustc-1.74.0/lib $BUILD/opt/rustc-1.74.0/bin/rustc
sudo patchelf --set-rpath /opt/rustc-1.74.0/lib $BUILD/opt/rustc-1.74.0/lib/librustc_driver-*

# Clean up
sudo rm -v /usr/bin/c++
unset OPENSSL_NO_VENDOR RUST_BACKTRACE BOOTSTRAP rlib_dir
unset HOST_CC  HOST_CFLAGS  ZSTD_SYS_USE_PKG_CONFIG
unset LIBGIT2_NO_VENDOR CARGO_BUILD_JOBS CARGO_PROFILE_RELEASE_CODEGEN_UNITS
unset PKG_CONFIG_ALLOW_CROSS CBUILD_TARGET_SYSROOT

cd $BUILD && sudo -S mkdir -v ${BUILD}/install &&
cat > /tmp/slack-desc << "EOF"
# HOW TO EDIT THIS FILE:
# The "handy ruler" below makes it easier to edit a package description.  Line
# up the first '|' above the ':' following the base package name, and the '|'
# on the right side marks the last column you can put a character in.  You must
# make exactly 11 lines for the formatting to be correct.  It's also
# customary to leave one space after the ':' except on otherwise blank lines.

          |-----handy-ruler------------------------------------------------------|
rustc-tiny: rustc-tiny
rustc-tiny:
rustc-tiny: Rust is a curly-brace, block-structured expression language.
rustc-tiny: This includes only the official rust compiler and standard rust 
rustc-tiny: library.
rustc-tiny:
rustc-tiny: Homepage: https://rust-lang.org
rustc-tiny:
EOF
sudo -S mv -v /tmp/slack-desc install/ &&
sudo -S makepkg -l y -c n $PKGS/rustc-tiny-1.74.0-$PSUFFIX &&
sudo -S rm -rf ${BUILD}/*