#!/bin/sh

# ===== Overview

# This script is designed to download, compile, and install Fil-C
# using paths suitable for Debian (and various other distributions),
# viewing Fil-C as a cross-compiler for purposes of Debian packaging.
# The main installation is in /usr/libexec/fil/x86_64 (about 13GB).
# The compilation directory (>50GB) can be removed afterwards.
# Symlinks installed from other directories into the main installation:
#   /usr/bin/{filcc,fil++}
#   /usr/bin/x86_64fil-linux-gnu-{gcc,g++,objdump}
#   /usr/lib/x86_64fil-linux-gnu
#   /usr/include/x86_64fil-linux-gnu
# The compiler's default search paths:
#   /usr/include/x86_64fil-linux-gnu:/usr/include
#   /usr/lib/x86_64fil-linux-gnu:/usr/lib
# The Fil-C compilation of glibc-2.40
# is installed in /usr/lib/x86_64fil-linux-gnu
# with include files in /usr/include/x86_64fil-linux-gnu;
# /usr/include would be safe if system version of glibc matched,
# but not worth taking risks for a few MB of .h files.

# ===== Prerequisites

# Need quite a bit of disk space. 80GB is enough.

# Need some compilation tools. The following should suffice (probably overkill):
# apt install autoconf-dickey build-essential bison clang cmake gawk gettext ninja-build patchelf quilt ruby texinfo time

# Need the compiling user (e.g., filian) to be able to run sudo:
# echo 'filian ALL=(ALL) ROLE=unconfined_r TYPE=unconfined_t NOPASSWD: ALL' > /etc/sudoers.d/filian

# =====

# Copyright (c) 2025 Epic Games, Inc. All Rights Reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY EPIC GAMES, INC. ``AS IS AND ANY
# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL EPIC GAMES, INC. OR
# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
# EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
# PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
# OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 

# 20251029 djb:
# * start from build_all_fast_glibc.sh
# * merge shell scripts used, but skip overrides
# * assume Linux and amd64
# * reorganize and streamline a bit
# * main point: install in /usr/libexec/fil instead of ./pizfix
# * create symlinks from /usr/include/x86_64fil-linux-gnu etc.

# =====

set -e
set -x

umask 022

MAKE=make
CCPREFIX=""

ARCH=x86_64
LLVMARCH=X86
INCLARCH=/usr/include/${ARCH}-linux-gnu
INCLARCHFIL=/usr/include/${ARCH}fil-linux-gnu
LIBARCHFIL=/usr/lib/${ARCH}fil-linux-gnu
BINARCHFIL=/usr/bin/${ARCH}fil-linux-gnu
TOP=/usr/libexec/fil/$ARCH

NCPU=`nproc`

CMAKEOPTIONS="-S ../llvm -B . -G Ninja -DLLVM_ENABLE_PROJECTS=clang
    -DCMAKE_BUILD_TYPE=RelWithDebInfo -DLLVM_ENABLE_ASSERTIONS=ON
    -DLLVM_ENABLE_RUNTIMES=libcxx;libcxxabi
    -DLIBCXXABI_HAS_PTHREAD_API=ON -DLIBCXX_ENABLE_EXCEPTIONS=ON
    -DLIBCXXABI_ENABLE_EXCEPTIONS=ON -DLIBCXX_HAS_PTHREAD_API=ON
    -DLLVM_ENABLE_ZSTD=OFF -DLIBCXXABI_USE_LLVM_UNWINDER=OFF
    -DLIBCXX_FORCE_LIBCXXABI=ON -DLLVM_TARGETS_TO_BUILD=$LLVMARCH
    -DLLVM_ENABLE_LIBXML2=OFF -DLLVM_ENABLE_LIBEDIT=OFF
    -DLLVM_ENABLE_LIBPFM=OFF -DLLVM_ENABLE_ZLIB=OFF -DLLVM_ENABLE_ZSTD=OFF
    -DLLVM_ENABLE_CURL=OFF -DLLVM_ENABLE_HTTPLIB=OFF
    -DLLVM_STATIC_LINK_CXX_STDLIB=ON -DCMAKE_EXE_LINKER_FLAGS=-static-libgcc"

# ===== obtain and slightly patch repo

git clone https://github.com/pizlonator/fil-c.git
cd fil-c
git checkout 1bc85c2bc8fee42221379ea45275674d5aa96b2a
sed -i s/pizfix/top/g libpas/Makefile

patch -p1 << 'EOF'
diff --git a/clang/lib/Driver/ToolChains/Gnu.cpp b/clang/lib/Driver/ToolChains/Gnu.cpp
index ee4deb44d28a..029c4a4d261f 100644
--- a/clang/lib/Driver/ToolChains/Gnu.cpp
+++ b/clang/lib/Driver/ToolChains/Gnu.cpp
@@ -593,7 +593,12 @@ void tools::gnutools::Linker::ConstructJob(Compilation &C, const JobAction &JA,
   CmdArgs.push_back(Output.getFilename());
 
   auto GetYoloLibPath = [&] (const StringRef str) -> std::string {
-    if (ToolChain.getDriver().HasPizfix) {
+    // 20251029 djb: focusing here on debian on amd64
+    if ((true)) {
+      SmallString<128> P("/usr/lib/x86_64fil-linux-gnu");
+      llvm::sys::path::append(P, str);
+      return std::string(P);
+    } else if (ToolChain.getDriver().HasPizfix) {
       SmallString<128> P(ToolChain.getDriver().Dir);
       llvm::sys::path::append(P, "..", "..", "pizfix");
       llvm::sys::path::append(P, "lib", str);
@@ -610,6 +615,8 @@ void tools::gnutools::Linker::ConstructJob(Compilation &C, const JobAction &JA,
   };
 
   auto GetGCCLibPath = [&] (const char* str) -> std::string {
+    // 20251029 djb: focusing here on debian on amd64
+    return ToolChain.GetFilePath(str);
     if (ToolChain.getDriver().HasPizfix || ToolChain.getDriver().HasOptfil)
       return ToolChain.GetFilePath(str);
     // FIXME LMAO
@@ -680,7 +687,15 @@ void tools::gnutools::Linker::ConstructJob(Compilation &C, const JobAction &JA,
 
   Args.AddAllArgs(CmdArgs, options::OPT_L);
 
-  if (ToolChain.getDriver().HasPizfix) {
+  // 20251029 djb: focusing here on debian on amd64
+  if ((true)) {
+    CmdArgs.push_back("-L/usr/lib/x86_64fil-linux-gnu");
+    CmdArgs.push_back("-rpath");
+    CmdArgs.push_back("/usr/lib/x86_64fil-linux-gnu");
+    CmdArgs.push_back("-L/usr/lib");
+    CmdArgs.push_back("-rpath");
+    CmdArgs.push_back("/usr/lib");
+  } else if (ToolChain.getDriver().HasPizfix) {
     {
       SmallString<128> P(ToolChain.getDriver().Dir);
       llvm::sys::path::append(P, "..", "..", "pizfix", "lib64");
@@ -737,7 +752,10 @@ void tools::gnutools::Linker::ConstructJob(Compilation &C, const JobAction &JA,
     if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs,
                      options::OPT_r) ||
         Args.hasArg(options::OPT_normalcrt)) {
-      if (ToolChain.getDriver().HasPizfix) {
+      // 20251029 djb: focusing here on debian on amd64
+      if ((true)) {
+        CmdArgs.push_back("/usr/lib/x86_64fil-linux-gnu/filc_crt.o");
+      } else if (ToolChain.getDriver().HasPizfix) {
         SmallString<128> P(ToolChain.getDriver().Dir);
         llvm::sys::path::append(P, "..", "..", "pizfix", "lib");
         llvm::sys::path::append(P, "filc_crt.o");
@@ -747,7 +765,10 @@ void tools::gnutools::Linker::ConstructJob(Compilation &C, const JobAction &JA,
       else
         CmdArgs.push_back("/usr/lib/filc_crt.o");
     } else {
-      if (ToolChain.getDriver().HasPizfix) {
+      // 20251029 djb: focusing here on debian on amd64
+      if ((true)) {
+        CmdArgs.push_back("/usr/lib/x86_64fil-linux-gnu/filc_mincrt.o");
+      } else if (ToolChain.getDriver().HasPizfix) {
         SmallString<128> P(ToolChain.getDriver().Dir);
         llvm::sys::path::append(P, "..", "..", "pizfix", "lib");
         llvm::sys::path::append(P, "filc_mincrt.o");
diff --git a/clang/lib/Driver/ToolChains/Linux.cpp b/clang/lib/Driver/ToolChains/Linux.cpp
index 6ed5145451ea..249924d5ba5e 100644
--- a/clang/lib/Driver/ToolChains/Linux.cpp
+++ b/clang/lib/Driver/ToolChains/Linux.cpp
@@ -456,6 +456,10 @@ std::string Linux::getDynamicLinker(const ArgList &Args) const {
   const llvm::Triple::ArchType Arch = getArch();
   const llvm::Triple &Triple = getTriple();
 
+  // 20251029 djb: focusing here on debian on amd64
+  // XXX: figure out a broader trigger later
+  return "/usr/lib/x86_64fil-linux-gnu/ld-yolo-x86_64.so";
+
   if ((true)) {
     if (getDriver().HasPizfix) {
       SmallString<128> P(getDriver().Dir);
@@ -654,7 +658,11 @@ void Linux::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
   const Driver &D = getDriver();
   std::string SysRoot = computeSysRoot();
 
-  if (D.HasPizfix) {
+  // 20251029 djb: focusing here on debian on amd64
+  if ((true)) {
+    addSystemInclude(DriverArgs, CC1Args, "/usr/include/x86_64fil-linux-gnu");
+    addSystemInclude(DriverArgs, CC1Args, "/usr/include");
+  } else if (D.HasPizfix) {
     {
       SmallString<128> P(D.Dir);
       llvm::sys::path::append(P, "..", "..", "pizfix", "stdfil-include");
EOF

# ===== initialize target directories

sudo sh -c "
  set -e
  set -x
  rm -rf $TOP
  mkdir -p $TOP /usr/include /usr/lib
  rm -rf $INCLARCHFIL
  ln -s $TOP/include $INCLARCHFIL
  rm -rf $LIBARCHFIL
  ln -s $TOP/lib $LIBARCHFIL
  chown $USER $TOP # will revert later
"
rm -rf top
ln -s $TOP top

# ===== maybe clean up build directory

EXPECTEDCOOKIECONTENTS="$HOSTNAME:$PWD ::: $CMAKEOPTIONS"
COOKIENAME=filc_cookie_2.txt

if test -e build/$COOKIENAME
then
  ACTUALCOOKIECONTENTS=`cat build/$COOKIENAME`
else
  ACTUALCOOKIECONTENTS=""
fi

if test "x$ACTUALCOOKIECONTENTS" != "x$EXPECTEDCOOKIECONTENTS"
then
  rm -rf build
  mkdir -p build
  ( cd build
    cmake $CMAKEOPTIONS
    echo "$EXPECTEDCOOKIECONTENTS" > $COOKIENAME
  )
fi

# ===== build/bin/clang-20 and friends

( cd build && ninja clang
)

patchelf --remove-rpath build/bin/clang-20

# ===== $TOP/include/* from filc/include/*
# ===== $TOP/include/asm as symlink to $INCLARCH/asm

rm -rf $TOP/include
mkdir -p $TOP/include
cp filc/include/* $TOP/include/
ln -s $INCLARCH/asm $TOP/include/asm

# ===== $TOP/yolo-include
# ===== $TOP/lib

( cd projects/yolo-glibc-2.40
  rm -f configure
  autoconf
)

( rm -rf pizlonated-yolo-glibc-build
  mkdir pizlonated-yolo-glibc-build
  cd pizlonated-yolo-glibc-build
  ../projects/yolo-glibc-2.40/configure --prefix=$TOP/yolo --disable-mathvec
  make -j $NCPU
  make -j $NCPU install
)

( cd $TOP

  OLDLDNAME=ld-linux-x86-64.so.2
  OLDLIBCIMPLNAME=libc.so.6
  OLDLIBCNONSHAREDNAME=libc_nonshared.a
  OLDLIBMIMPLNAME=libm.so.6
  OLDSTATICLIBCNAME=libc.a
  OLDSTATICLIBMNAME=libm.a

  LDNAME=ld-yolo-x86_64.so
  LIBNAMEBASE=libyolo
  LIBCNAMEBASE=${LIBNAMEBASE}c
  LIBCNAME=${LIBCNAMEBASE}.so
  LIBCIMPLNAME=${LIBCNAMEBASE}impl.so
  LIBCNONSHAREDNAME=${LIBCNAMEBASE}_nonshared.a
  LIBMIMPLNAME=${LIBNAMEBASE}mimpl.so
  LIBMNAME=${LIBNAMEBASE}m.so
  STATICLIBCNAME=${LIBCNAMEBASE}.a
  STATICLIBMNAME=${LIBNAMEBASE}m.a

  mkdir -p lib
  cp yolo/lib/$OLDLDNAME lib/$LDNAME
  cp yolo/lib/$OLDLIBCIMPLNAME lib/$LIBCIMPLNAME
  cp yolo/lib/$OLDLIBCNONSHAREDNAME lib/$LIBCNONSHAREDNAME
  cp yolo/lib/$OLDLIBMIMPLNAME lib/$LIBMIMPLNAME
  cp yolo/lib/*.o lib/
  cp yolo/lib/$OLDSTATICLIBCNAME lib/$STATICLIBCNAME
  cp yolo/lib/$OLDSTATICLIBMNAME lib/$STATICLIBMNAME
  patchelf --replace-needed $OLDLDNAME $LDNAME lib/$LIBCIMPLNAME
  patchelf --set-soname $LIBCIMPLNAME lib/$LIBCIMPLNAME
  patchelf --set-soname $LDNAME lib/$LDNAME
  patchelf --replace-needed $OLDLDNAME $LDNAME lib/$LIBMIMPLNAME
  patchelf --replace-needed $OLDLIBCIMPLNAME $LIBCIMPLNAME lib/$LIBMIMPLNAME
  patchelf --set-soname $LIBMIMPLNAME lib/$LIBMIMPLNAME
  echo "OUTPUT_FORMAT(elf64-x86-64)" > lib/$LIBCNAME
  echo "GROUP ( $PWD/lib/$LIBCIMPLNAME $PWD/lib/$LIBCNONSHAREDNAME  AS_NEEDED ( $PWD/lib/$LDNAME ) )" >> lib/$LIBCNAME
  echo "OUTPUT_FORMAT(elf64-x86-64)" > lib/$LIBMNAME
  echo "GROUP ( $PWD/lib/$LIBMIMPLNAME )" >> lib/$LIBMNAME

  rm -rf yolo-include
  mv yolo/include yolo-include
  rm -rf yolo
  ln -s . yolo # XXX: there are still refs to yolo
  
  # help libpas because it compiles with nostdinc:
  ln -s $INCLARCH/asm yolo-include/
  ln -s /usr/include/asm-generic yolo-include/
  ln -s /usr/include/linux yolo-include/
)

# ===== $TOP/lib/{filc_crt.o,filc_mincrt.o,libpizlo.a,libpizlo.so}
# ===== $TOP/lib_gcverify/libpizlo.so
# ===== $TOP/lib_test/libpizlo.so
# ===== $TOP/lib_test_gcverify/libpizlo.so
# ===== plus some $TOP/* empty directories

( cd libpas
  $MAKE -f Makefile clean

  # XXX: most of these logically belong elsewhere
  mkdir -p build
  mkdir -p $TOP/include
  mkdir -p $TOP/bin
  mkdir -p $TOP/sbin
  mkdir -p $TOP/libexec
  mkdir -p $TOP/share
  mkdir -p $TOP/lib
  mkdir -p $TOP/lib_gcverify
  mkdir -p $TOP/lib_test
  mkdir -p $TOP/lib_test_gcverify
  mkdir -p $TOP/man
  mkdir -p $TOP/man/man1

  $MAKE -f Makefile -j $NCPU
)

# ===== $TOP/bin/* for glibc
# ===== $TOP/etc/* for glibc
# ===== $TOP/libexec/* for glibc
# ===== $TOP/sbin/* for glibc
# ===== $TOP/share/* for glibc
# ===== $TOP/var/* for glibc
# ===== $TOP/include/* extended for glibc
# ===== $TOP/lib/* extended for glibc

( cd projects/user-glibc-2.40
  rm -f configure
  autoconf
)

( rm -rf pizlonated-user-glibc-build
  mkdir pizlonated-user-glibc-build
  cd pizlonated-user-glibc-build
  CC="$PWD/../build/bin/clang -nostdlibinc -Wno-ignored-attributes -Wno-pointer-sign -Wno-unused-command-line-argument -Wno-macro-redefined" CXX="$PWD/../build/bin/clang++ -nostdlibinc -Wno-ignored-attributes -Wno-pointer-sign" ../projects/user-glibc-2.40/configure --prefix=$TOP --disable-mathvec
  make -j $NCPU
  make -j $NCPU install
)

# ===== $TOP/include/crypt.h
# ===== $TOP/include/xcrypt.h
# ===== $TOP/lib/lib*crypt*
# ===== $TOP/lib/pkgconfig
# ===== $TOP/share/man

( cd projects/libxcrypt-4.4.36
  rm -rf extracted-source
  git archive --format=tar HEAD --prefix=extracted-source/ | tar -xf -
  git diff --relative HEAD . | (cd extracted-source && patch -p1)
  cd extracted-source
  CC=$PWD/../../../build/bin/clang ./configure --prefix=$TOP
  make -j $NCPU
  make -j $NCPU install
)

# ===== $TOP/lib/libc++*

( cd build
  ninja runtimes-clean
  ninja runtimes
)

cp build/lib/x86_64-unknown-linux-gnu/libc++.so $TOP/lib
cp build/lib/x86_64-unknown-linux-gnu/libc++.so.1.0 $TOP/lib
cp build/lib/x86_64-unknown-linux-gnu/libc++abi.so.1.0 $TOP/lib
cp build/lib/x86_64-unknown-linux-gnu/libc++.a $TOP/lib
cp build/lib/x86_64-unknown-linux-gnu/libc++abi.a $TOP/lib
( cd $TOP/lib &&
  ln -fs libc++.so.1.0 libc++.so.1 &&
  ln -fs libc++abi.so.1.0 libc++abi.so.1 &&
  ln -fs libc++abi.so.1 libc++abi.so
)

patchelf --remove-rpath build/bin/clang-20

# ===== extend $TOP/bin/* for compiler

mkdir -p $TOP/bin
ls build/bin |
while read fn
do
  case $fn in
    clang|clang++|clang-cl|clang-cpp|fil++|filcc|filcpp|g++|gcc|llvm-ranlib|llvm-readelf|llvm-strip)
      ;;
    *)
      cp build/bin/$fn $TOP/bin/
  esac
done

( cd $TOP/bin
  ln -fs clang-20 filcc
  ln -fs clang-20 fil++
  ln -fs clang-20 filcpp
  ln -fs clang-20 gcc
  ln -fs clang-20 g++
  ln -fs clang-20 clang
  ln -fs clang-20 clang++
  ln -fs clang-20 clang-cl
  ln -fs clang-20 clang-cpp
  ln -fs llvm-ar llvm-ranlib
  ln -fs llvm-readobj llvm-readelf
  ln -fs llvm-objcopy llvm-strip
)
rm -rf $TOP/build
ln -s . $TOP/build # to help filc/run-tests

# ===== extend $TOP/include/* for compiler

cp -r build/include/c++ $TOP/include/
cp -r build/include/${ARCH}* $TOP/include/

# ===== extend $TOP/lib/* for compiler

cp -r build/lib/clang $TOP/lib/

# ===== install ${BINARCHFIL}-{filcc,fil++,gcc,g++,objdump}
# and have root own everything

sudo sh -c "
  ln -fs $TOP/bin/filcc /usr/bin/filcc
  ln -fs $TOP/bin/fil++ /usr/bin/fil++
  ln -fs $TOP/bin/gcc ${BINARCHFIL}-gcc
  ln -fs $TOP/bin/g++ ${BINARCHFIL}-g++
  ln -fs $TOP/bin/llvm-objdump ${BINARCHFIL}-objdump
  chown -R root:root $TOP
"

# ===== tests

filc/run-tests -p $TOP/bin