#! /usr/bin/env bash

source util.sh

VERSION=$1
PREFIX="$2"
URL="https://ftp.gnu.org/gnu/gcc/gcc-$VERSION/gcc-$VERSION.tar.xz"
ARCHIVE=$(basename "$URL")

# Final location of gcc in the sysroot
SYSROOT_GCC="$SYSROOT/bin/sh-elf-gcc"
# Version string of any existing sh-elf-gcc in the sysroot
SYSROOT_GCC_VERSION=
# "1" if libstdc++-v3 is already in the install folder
SYSROOT_HAS_LIBSTDCXX=
# "1" if the conditions for building libstdc++-v3 are met
CAN_BUILD_LIBSTDCXX=

#---
# Determine what parts of GCC are already installed and decide whether to build
#---

if [[ -f "$SYSROOT_GCC" ]]; then
  SYSROOT_GCC_VERSION=$("$SYSROOT_GCC" --version | head -n 1 | grep -Eo '[0-9.]+$')

  # TODO: Once we start using the full C++ library, check for libstdc++.a instead
  LIBSTDCXX_FILE=$("$SYSROOT_GCC" -print-file-name=libsupc++.a)
  LIBC_FILE=$("$SYSROOT_GCC" -print-file-name=libc.a)

  if [[ "$LIBSTDCXX_FILE" != "libsupc++.a" ]]; then
    SYSROOT_HAS_LIBSTDCXX=1
    echo "$TAG libsupc++.a found, libstdc++-v3 is already built"
  fi

  if [[ "$LIBC_FILE" != "libc.a" ]]; then
    CAN_BUILD_LIBSTDCXX=1
    [[ "$SYSROOT_HAS_LIBSTDCXX" != "1" ]] && \
      echo "$TAG libc.a found, we can build libstdc++-v3"
  else
    echo "$TAG libc.a not found, we cannot build libstdc++-v3"
  fi
else
  echo "$TAG After installing the libc, rebuild here for libstdc++-v3"
fi

if [[ "$SYSROOT_GCC_VERSION" = "$VERSION" ]]; then
  if [[ "$SYSROOT_HAS_LIBSTDCXX" = "1" ]]; then
    echo "$TAG GCC $VERSION with libstdc++-v3 already there; skipping rebuild"
    mkdir -p build
    touch build/giteapc-skip-rebuild.txt
    exit 0
  elif [[ "$CAN_BUILD_LIBSTDCXX" != "1" ]]; then
    echo "$TAG Cannot build libstdc++-v3 yet; skipping rebuild until next time"
    mkdir -p build
    touch build/giteapc-skip-rebuild.txt
    exit 0
  else
    echo "$TAG We will proceed with the second stage and build libstdc++-v3"
  fi
fi

if [[ ! -z "$ACCEPT_ANY" && ! -z "$SYSROOT_GCC_VERSION" ]]; then
  echo "$TAG GCC $VERSION already available; skipping rebuild as per ACCEPT_ANY"
  mkdir -p build
  touch build/giteapc-skip-rebuild.txt
  exit 0
fi

[[ -e "build/giteapc-skip-rebuild.txt" ]] && rm build/giteapc-skip-rebuild.txt

#---
# Get sources
#---

if [[ -f "$ARCHIVE" ]]; then
  echo "$TAG Found $ARCHIVE, skipping download"
else
  echo "$TAG Downloading $URL..."
  if command -v curl >/dev/null 2>&1; then
    curl $URL -o $ARCHIVE
  elif command -v wget >/dev/null 2>&1; then
    wget -q --show-progress $URL -O $ARCHIVE
  else
    echo "$TAG error: no curl or wget; install one or download archive yourself" >&2
    exit 1
  fi
fi

# Extract archive (OpenBSD-compliant version)
if [[ -d "${ARCHIVE%.tar.*}" ]]; then
  echo "$TAG Found ${ARCHIVE%.tar.*}, skipping extraction"
else
  echo "$TAG Extracting $ARCHIVE..."
  unxz -c < $ARCHIVE | tar -xf -

  if [[ "$VERSION" = "11.1.0" ]]; then
    echo "$TAG Applying patches/gcc-11.1.0-libstdc++-v3-skip-dlopen.patch..."
    patch -u -N -p0 < patches/gcc-11.1.0-libstdc++-v3-skip-dlopen.patch
  fi
fi

# Download prerequisites
cd gcc-$VERSION
./contrib/download_prerequisites
cd ..

#---
# Configure
#---

# We install in the sysroot and then symlink to the PREFIX folder in the path.

# Symlink as, ld, ar and ranlib, which gcc will not find by itself (we renamed
# them from sh3eb-elf-* to sh-elf-* with --program-prefix).
mkdir -p "$SYSROOT/sh3eb-elf/bin"
for TOOL in as ld ar ranlib; do
  if ! command -v sh-elf-$TOOL >/dev/null 2>&1; then
    echo "error: sh-elf-$TOOL not found in PATH!" >&2
    exit 1
  fi
  ln -sf $(command -v sh-elf-$TOOL) "$SYSROOT/sh3eb-elf/bin/$TOOL"
done

# OpenBSD apparently installs these in /usr/local
if [[ $(uname) == "OpenBSD" ]]; then
  EXTRA_ARGS="--with-gmp=/usr/local --with-mpfr=/usr/local --with-mpc=/usr/local"
else
  EXTRA_ARGS=
fi

# In libstdc++-v3 mode, don't reconfigure to avoid recompiling
if [[ "$SYSROOT_GCC_VERSION" = "$VERSION" && "$SYSROOT_HAS_LIBSTDCXX" != "1" && "$CAN_BUILD_LIBSTDCXX" = "1" ]]; then
  touch build/giteapc-build-libstdcxx.txt
elif [[ "$SYSROOT_GCC_VERSION" != "$VERSION" ]]; then
  echo "$TAG Configuring gcc..."
  [[ -d build ]] && rm -rf build
  mkdir build

  cd build
  run_quietly giteapc-configure.log         \
  ../gcc-$VERSION/configure                 \
    --prefix="$SYSROOT"                     \
    --target="sh3eb-elf"                    \
    --with-multilib-list="m3,m4-nofpu"      \
    --enable-languages="c,c++"              \
    --without-headers                       \
    --program-prefix="sh-elf-"              \
    --enable-libssp                         \
    --enable-lto                            \
    --enable-clocale="generic"              \
    --enable-libstdcxx-allocator            \
    --disable-threads                       \
    --disable-libstdcxx-verbose             \
    --enable-cxx-flags="-fno-exceptions"    \
    $EXTRA_ARGS
  cd ..
else
  echo "$TAG GCC already built, can't build libstdc++-v3; skipping!"
  touch build/giteapc-skip-rebuild.txt
  exit 0
fi