#!/bin/sh
set -e

# To initialize/enter chroot:
# mkdir dev tmp
# mknod dev/null c 1 3
# mknod dev/tty c 5 0
# ./bin/busybox chroot . /bin/busybox env -i NPROC="$(nproc)" /bin/busybox sh /sources/build_bootstrap.sh

# Amount of make threads, configure this to your liking.
# This can be obtained using `getconf _NPROCESSORS_ONLN`, but requires /proc
#   to be mounted, which we avoid.
NPROC="${NPROC:-4}"

# Creates a busybox symlink, useful to keep track of what bootstrap binaries
#   are necessary at what stages.
link() {
    for x in "$@"; do 
        if [ ! -e /bin/$x ]; then
            busybox ln -s busybox /bin/$x
        fi
    done
}
link sh

# TODO: Either start using tar-1.14 in the bootstrap or implement the
#         -j/--bzip2 option into tar-1.12, to avoid the awkward tar commands.
# TODO: Figure out what causes the timestamps to go bad with tar-1.12 (maybe use 1.13?)

cd /sources


#### Build Mes and its libc from the 4 necessary bootstrap bins
export PATH=/mes/bin:/bin

link cp mkdir rm tar zcat

# nyacc (0.99.3):
rm -rf nyacc-0.99.3
zcat nyacc-0.99.3.tar.gz | tar x
mkdir -p /mes/share/guile/site/2.2
cp -a nyacc-0.99.3/module/nyacc /mes/share/guile/site/2.2
rm -rf nyacc-0.99.3

link basename cat chmod cmp dirname echo ln sed

# mes-boot (0.22):
rm -rf mes-0.22
zcat mes-0.22.tar.gz | tar x
( cd mes-0.22
    # "grep: command not found" is harmless here, as the results are identical.
    CC=true ./configure.sh --host=x86-linux-mes --prefix=/mes
    CC="$PWD/scripts/mescc" ./bootstrap.sh

    # Optional, make sure the rebuilt mes still matches.
    cmp bin/mes /mes/bin/mes

    # Installing manually to avoid reliance on "tar --create"
    #BASHOPTS= ./install.sh
    set -x
    mkdir -p /mes/bin/
    cp -a bin/mes scripts/mesar scripts/mescc.scm scripts/mescc scripts/diff.scm /mes/bin/
    cp -a include /mes/
    mkdir -p /mes/lib/linux/
    cp -a lib/x86-mes /mes/lib/
    cp -a lib/linux/x86-mes /mes/lib/linux/
    cp -a gcc-lib/x86-mes/* /mes/lib/
    cp -a mescc-lib/x86-mes /mes/lib/
    mkdir -p /mes/share/mes/
    cp -a mes/module /mes/share/mes/
    mkdir -p /mes/share/guile/site/2.2
    cp -a module/* /mes/share/guile/site/2.2
)
rm -rf mes-0.22

link install

# mescc-tools (1.0.1):
# This step is completely optional, as identical tools are already installed.
# However, as a sanity check it's done anyway.
rm -rf mescc-tools-Release_1.0.1
zcat mescc-tools-Release_1.0.1.tar.gz | tar x
( cd mescc-tools-Release_1.0.1
    #make -Bn M1 hex2 blood-elf COMMIT= CC=mescc CFLAGS='-lc+tcc'
    set -x

    mkdir -p bin
    mescc -lc+tcc M1-macro.c functions/file_print.c functions/match.c functions/numerate_number.c functions/string.c functions/require.c functions/in_set.c -o bin/M1
    mescc -lc+tcc hex2_linker.c functions/file_print.c functions/match.c functions/numerate_number.c functions/require.c functions/in_set.c -o bin/hex2
    mescc -lc+tcc blood-elf.c functions/file_print.c functions/match.c functions/require.c functions/in_set.c functions/numerate_number.c -o bin/blood-elf

    # Optional, make sure the tools built with the new mes still match.
    cmp bin/M1 /mes/bin/M1
    cmp bin/hex2 /mes/bin/hex2
    cmp bin/blood-elf /mes/bin/blood-elf

    install -Dm755 bin/M1 /mes/bin/M1
    install -Dm755 bin/hex2 /mes/bin/hex2
    install -Dm755 bin/blood-elf /mes/bin/blood-elf
)
rm -rf mescc-tools-Release_1.0.1


#### Bootstrap TCC, with mes-libc
# Using the C library provided by Mes, we build the Tiny C Compiler to use it,
#   to later be able to build a bunch of tools from this combination.
export PATH=/tcc/bin:/mes/bin:/bin
rm -rf /tcc

# tcc-boot0 (0.9.26):
# This step will take a _long_ time, because mescc is a slow compiler, as a
#   result of how minimal its core is designed.
# Thankfully, things will speed up considerably once TCC is bootstrapped.
rm -rf tcc-0.9.26-1103-g6e62e0e
zcat tcc-0.9.26-1103-g6e62e0e.tar.gz | tar x
( cd tcc-0.9.26-1103-g6e62e0e
    echo '#define TCC_VERSION "0.9.27"' > config.h
    MES_PREFIX=/mes prefix=/tcc ./bootstrap.sh  # Slow!

    # Installing manually to avoid reliance on "tar --create"
    #MES_PREFIX=/mes prefix=/tcc ./install.sh
    mkdir -p /tcc/bin/
    cp tcc /tcc/bin/
    cp -a /mes/include /tcc/
    mkdir -p /tcc/lib/tcc/
    cp -a crt1.o crti.o crtn.o libc.a libgetopt.a /tcc/lib/
    cp -a libtcc1.a /tcc/lib/tcc/
)
rm -rf tcc-0.9.26-1103-g6e62e0e

# This binary was only necessary for the optional checks in mes-boot,
#   mescc-tools, as well as tcc-boot0's bootstrap.sh
# Possible future removal/implementation in mes?
rm /bin/cmp


#### Build compression tools, upgrade TCC to 0.9.27.
# Upgrading TCC is probably not truly necessary, but it hardly hurts.
# Some tools are required to achieve this, but these tools will be necessary
#   later on, regardless.
export PATH=/tcc/bin:/bin

# sed-mesboot (1.18):
# Used by nearly every configure script, and in this script to patch sources.
# It's only used for the mes-boot configure.sh before this point.
# May be possible to move out of the bootstrap bins in the future.
rm -rf sed-1.18
zcat sed-1.18.tar.gz | tar x
( cd sed-1.18
    set -x
    tcc -DREGEX_MALLOC=1 -DSTDC_HEADERS=1 -DHAVE_MEMCPY=1 -o sed sed.c utils.c regex.c getopt.c getopt1.c
    install -Dm755 sed /bin/sed
)
rm -rf sed-1.18

link mv

# gzip-mesboot (1.2.4):
# Reduces the reliance on the bootstrap binary for gzip, as that only has to be
#   used to decompress archives. Glibc requires it to compress.
# This, along with `tar` should be rebuilt as soon as possible due to how many
#   packages rely on these, but `tar` unfortunately has a few more dependencies.
rm -rf gzip-1.2.4
zcat gzip-1.2.4.tar.gz | tar x
( cd gzip-1.2.4
    sed -e 's/^char [*]strlwr/&_/' util.c > /tmp/sed; mv /tmp/sed util.c

    set -x
    tcc -DNO_UTIME_H -DHAVE_UNISTD_H -o gzip gzip.c zip.c deflate.c trees.c bits.c unzip.c inflate.c util.c crypt.c lzw.c unlzw.c unpack.c unlzh.c getopt.c
    install -Dm755 gzip /bin/gzip
    ln -sf gzip /bin/gunzip
    ln -sf gzip /bin/zcat
)
rm -rf gzip-1.2.4

# bzip2-mesboot (1.0.8):
# This compressor isn't part of the bootstrap binaries, but is necessary for
#   unpacking certain archives, including tcc-0.9.27.tar.bz2...
rm -rf bzip2-1.0.8
zcat bzip2-1.0.8.tar.gz | tar x
( cd bzip2-1.0.8
    # mes-libc-0.22 uses the value 0 for stdin, which trips up a check.
    # This breaks decompressing data from stdin, through for example "tar jxf".
    # Patching it out is "fine", since enough checks cover other failure states.
    sed -e 's/if (f == NULL /if (0 /' bzlib.c > /tmp/sed; mv /tmp/sed bzlib.c

    echo '#define fchown(filedes, owner, group) 0' > utime.h
    echo '#define fchmod(filedes, mode) 0' >> utime.h
    echo 'struct utimbuf { int actime; int modtime; };' >> utime.h
    echo '#define utime(filename, buf) 0' >> utime.h

    set -x
    tcc -I. -o bzip2 blocksort.c huffman.c crctable.c randtable.c compress.c decompress.c bzlib.c bzip2.c
    install -Dm755 bzip2 /bin/bzip2
    ln -sf bzip2 /bin/bunzip2
    ln -sf bzip2 /bin/bzcat
)
rm -rf bzip2-1.0.8

# tcc-boot (0.9.27):
rm -rf tcc-0.9.27
bzcat tcc-0.9.27.tar.bz2 | tar x
( cd tcc-0.9.27
    sed -e 's/s->alacarte_link = 1;/s->static_link = 1;/' \
        libtcc.c > /tmp/sed; mv /tmp/sed libtcc.c
    echo '#define TCC_VERSION "0.9.27"' > config.h

    # Build tcc twice, as avoiding bootstrapping here breaks programs later
    set -x
    for x in a b; do
        tcc -vvv -DONE_SOURCE=1 \
            -DTCC_TARGET_I386 \
            -DCONFIG_TCC_STATIC \
            -DCONFIG_TCCDIR=\"/tcc/lib/tcc\" \
            -DCONFIG_TCC_CRTPREFIX=\"/tcc/lib\" \
            -DCONFIG_TCC_SYSINCLUDEPATHS=\"/tcc/include\" \
            -DCONFIG_TCC_LIBPATHS=\"/tcc/lib\" \
            -o tcc tcc.c
        ./tcc -vvv -c -o libtcc1.o lib/libtcc1.c
        ./tcc -ar rc libtcc1.a libtcc1.o
        install -Dm755 tcc /tcc/bin/tcc
        install -Dm644 libtcc1.a /tcc/lib/tcc/libtcc1.a
    done
)
rm -rf tcc-0.9.27


#### Build tools, round 1
# At this point we try to rebuild the bootstrap tools, to reduce the reliance
#   on them and their (minimal) featureset, and build some additional tools
#   required to build GCC2.
# Rebuilding the bootstrap tools as early as possible allows for simplification
#   of the bootstrap tools, which should lead to smaller binaries.
# Unfortunately, the following packages can not be built with TCC yet:
# - coreutils
# These are required to build GCC2, and the bootstrap binaries will be used.

# grep-mesboot (2.0):
# Required by most configure scripts, but we've been able to avoid it thus far.
rm -rf grep-2.0
zcat grep-2.0.tar.gz | tar x
( cd grep-2.0
    set -x
    tcc -DSTDC_HEADERS=1 -DHAVE_ALLOCA_H=1 -DHAVE_MEMCHR=1 -o grep grep.c getopt.c regex.c dfa.c kwset.c obstack.c search.c
    install -Dm755 grep /bin/grep
    ln -sf grep /bin/egrep
    ln -sf grep /bin/fgrep
)
rm -rf grep-2.0

link expr ls uniq sleep sort

# gnu-make-mesboot0 (3.80):
# Make is required to build nearly everything, so it has to be built as soon as
#   possible.
rm -rf make-3.80
bzcat make-3.80.tar.bz2 | tar x
( cd make-3.80
    sed -e 's/@REMOTE@/stub/' \
        -e 's/@LIBOBJS@/getloadavg.o/' \
        build.sh.in > /tmp/sed; mv /tmp/sed build.sh.in
    sed -e 's/^extern long int lseek.*/\/\/ &/' \
        make.h > /tmp/sed; mv /tmp/sed make.h
    CC=tcc LD=tcc ./configure \
        --build=i686-pc-linux-gnu \
        --disable-nls
    sh build.sh
    install -Dm755 make /bin/make
)
rm -rf make-3.80

# Multi-threaded make is broken at this stage
export MAKEFLAGS=-j1

link tr

# bash-mesboot0 (2.05b):
# A lot of shell scripts are ran during the build process.
# Bootstrapping it here allows the initial shell to remain simple.
# This shell is non-interactive, so the bootstrap shell might be used by the
#   user, instead, while this one just runs most scripts.
rm -rf bash-2.05b
zcat bash-2.05b.tar.gz | tar x
( cd bash-2.05b
    sed -e 's/mksyntax\.c$/& -lgetopt/' \
        -e 's/buildversion\.o$/& -lgetopt/' \
        Makefile.in > /tmp/sed; mv /tmp/sed Makefile.in
    sed -e 's/int name, namelen;/char *name; int namelen;/' \
        lib/sh/oslib.c > /tmp/sed; mv /tmp/sed lib/sh/oslib.c
    sed -e 's/defined (HAVE_LOCALE_H)/0/' \
        lib/sh/snprintf.c > /tmp/sed; mv /tmp/sed lib/sh/snprintf.c

    # Progcomp is disabled, so this file shouldn't be built...
    # TODO: --disable-progcomp should take care of this, figure out what's
    #         up with that.
    sed -e 's/ complete\.o$//' \
        builtins/Makefile.in > /tmp/sed; mv /tmp/sed builtins/Makefile.in

    # Delete unnecessary commands at end of build
    sed -e '/ls -l $(Program)$/d' \
        -e '/size $(Program)$/d' \
        Makefile.in > /tmp/sed; mv /tmp/sed Makefile.in

    CC='tcc -D_POSIX_VERSION=1' AR='tcc -ar' ./configure \
        --build=i686-pc-linux-gnu \
        --without-bash-malloc \
        --disable-readline \
        --disable-history \
        --disable-bang-history \
        --disable-progcomp \
        --disable-nls \
        bash_cv_getcwd_calls_popen=no \
        bash_cv_signal_vintage=posix \
        ac_cv_func_working_mktime=yes
    echo '#define endpwent(x) 0' >> config.h
    make bash
    install -Dm755 bash /bin/bash
    ln -sf bash /bin/sh
)
rm -rf bash-2.05b

# diffutils-mesboot (2.7):
# `cmp` is only absolutely required by tcc-boot0 thus far (though it should be
#   possible to patch out), and not strictly required until gcc-4.6.4's install
#   procedure.
# However, a lot of configure scripts do use it, and `diff` from time to time,
#   so it's a good thing to have as soon as possible, regardless.
rm -rf diffutils-2.7
zcat diffutils-2.7.tar.gz | tar x
( cd diffutils-2.7
    CC=tcc ./configure
    make cmp diff
    install -Dm755 cmp /bin/cmp
    install -Dm755 diff /bin/diff
)
rm -rf diffutils-2.7

# tar-mesboot0 (1.12), not in guix:
# Self explanatory, required to unpack archives. Might be possible to moved
#   earlier in the chain by avoiding the configure script/makefile.
# Softens the dependency on tar, since up until now it was only necessary to
#   unpack archives, while the install procedure of e.g. gcc, requires it to
#   also create archives.
rm -rf tar-1.12
zcat tar-1.12.tar.gz | tar x
( cd tar-1.12
    # Remove need for ls -L
    sed -e 's/ls -Lt /ls -t /' configure > /tmp/sed; mv /tmp/sed configure
    chmod +x configure

    CC=tcc ./configure --disable-nls
    make -C lib AR='tcc -ar'
    make -C src
    install -Dm755 src/tar /bin/tar
)
rm -rf tar-1.12

# gawk-mesboot0 (3.0.0):
# AWK is required to build glibc.
rm -rf gawk-3.0.0
zcat gawk-3.0.0.tar.gz | tar x
( cd gawk-3.0.0
    sed -e 's/date /echo today /' \
        configure > /tmp/sed; mv /tmp/sed configure
    sed -e 's/date /echo today /' \
        -e 's/ autoheader/ true/' \
        -e 's/ -lm//' \
        Makefile.in > /tmp/sed; mv /tmp/sed Makefile.in
    chmod +x configure

    ac_cv_func_getpgrp_void=yes ac_cv_func_tzset=yes \
    CC=tcc LD=tcc ./configure \
        --build=i686-pc-linux-gnu \
        --disable-nls
    make gawk
    install -Dm755 gawk /bin/gawk
    ln -sf gawk /bin/awk
)
rm -rf gawk-3.0.0

# patch-mesboot (2.5.9):
# Used to patch certain packages to fix bootstrap-specific build failures.
rm -rf patch-2.5.9
zcat patch-2.5.9.tar.gz | tar x
( cd patch-2.5.9
    CC=tcc ./configure
    make patch
    install -Dm755 patch /bin/patch
)
rm -rf patch-2.5.9

#coreutils? (fileutils, textutils, sh-utils)?


#### Bootstrap gcc2 toolchain, consisting of gcc-2.95.2, binutils-2.14, glibc-2.2.5
# Also rebuild it against itself to remove tcc and mes-libc from the picture.
# This will become the GNU toolchain that's the basis for the remaining set of tools.
export PATH=/gcc2/bin:/tcc/bin:/bin
rm -rf /gcc2

link touch true

# binutils-mesboot0 (2.14):
rm -rf binutils-2.14
bzcat binutils-2.14.tar.bz2 | tar x
( cd binutils-2.14
    # Fix some sed-related issues...
    sed -e 's/_frag=${srcdir}\//_frag=/' \
        configure > /tmp/sed; mv /tmp/sed configure
    sed -e "s@^sed -e '/SRC-POTFILES.*\$@echo -e 'all:\\\\n\\\\ttrue\\\\n\\\\ninstall:\\\\n\\\\ttrue\\\\n' > po/Makefile@" \
        bfd/configure > /tmp/sed; mv /tmp/sed bfd/configure
    chmod +x configure bfd/configure

    CC='tcc -D__GLIBC_MINOR__=6' AR='tcc -ar' ./configure \
        --host=i686-pc-linux-gnu \
        --prefix=/gcc2 \
        --with-sysroot \
        --with-lib-path=/gcc2/lib \
        --disable-shared \
        --disable-nls
    make
    make install
)
rm -rf binutils-2.14

# gcc-core-mesboot0 (2.95.3):
rm -rf gcc-2.95.3
zcat gcc-core-2.95.3.tar.gz | tar x
( cd gcc-2.95.3
    patch -p1 -i ../gcc-boot-2.95.3.patch

    CC='tcc -D__GLIBC_MINOR__=6' ./configure \
        --host=i686-pc-linux-gnu \
        --prefix=/gcc2 \
        --disable-shared
    rm -rf texinfo && touch gcc/cpp.info gcc/gcc.info
    make LIBGCC2_INCLUDES=-I/tcc/include
    make install

    set -x
    mkdir tmp
    cd tmp
    ar x ../gcc/libgcc2.a
    ar x /tcc/lib/tcc/libtcc1.a
    ar r /gcc2/lib/gcc-lib/i686-pc-linux-gnu/2.95.3/libgcc.a *.o
    cp ../gcc/libgcc2.a /gcc2/lib/libgcc2.a
)
rm -rf gcc-2.95.3

export PATH=/gcc2/bin:/bin

link pwd

# glibc-mesboot0 (2.2.5):
cp -ar linux-headers/include /gcc2/
rm -rf glibc-2.2.5
zcat glibc-2.2.5.tar.gz | tar x
( cd glibc-2.2.5
    patch -p1 -i ../glibc-boot-2.2.5.patch

    CC='gcc -DMES_BOOTSTRAP=1 -DBOOTSTRAP_GLIBC=1'" -L $PWD" ./configure \
        --host=i686-pc-linux-gnu \
        --prefix=/gcc2 \
        --with-headers=/gcc2/include \
        --disable-shared \
        --disable-sanity-checks \
        --enable-static-nss \
        --without-__thread \
        --without-cvs \
        --without-gd \
        --without-tls
    make
    make install
)
rm -rf glibc-2.2.5

# gcc-mesboot0 (2.95.3):
rm -rf gcc-2.95.3
zcat gcc-core-2.95.3.tar.gz | tar x
( cd gcc-2.95.3
    patch -p1 -i ../gcc-boot-2.95.3.patch

    ./configure \
        --host=i686-pc-linux-gnu \
        --prefix=/gcc2 \
        --disable-shared
    rm -r texinfo && touch gcc/cpp.info gcc/gcc.info
    make LIBGCC2_INCLUDES=-I/gcc2/include
    make install

    set -x
    mkdir tmp
    cd tmp
    ar x ../gcc/libgcc2.a
    ar r /gcc2/lib/gcc-lib/i686-pc-linux-gnu/2.95.3/libgcc.a *.o
    cp ../gcc/libgcc2.a /gcc2/lib/libgcc2.a
)
rm -rf gcc-2.95.3

# binutils-mesboot1 (2.14):
rm -rf binutils-2.14
bzcat binutils-2.14.tar.bz2 | tar x
( cd binutils-2.14
    # Fix some sed-related issues...
    sed -e 's/_frag=${srcdir}\//_frag=/' \
        configure > /tmp/sed; mv /tmp/sed configure
    sed -e "s@^sed -e '/SRC-POTFILES.*\$@echo -e 'all:\\\\n\\\\ttrue\\\\n\\\\ninstall:\\\\n\\\\ttrue\\\\n' > po/Makefile@" \
        bfd/configure > /tmp/sed; mv /tmp/sed bfd/configure
    chmod +x configure bfd/configure

    ./configure \
        --host=i686-pc-linux-gnu \
        --prefix=/gcc2 \
        --with-sysroot \
        --with-lib-path=/gcc2/lib \
        --disable-shared \
        --disable-nls
    make
    make install
)
rm -rf binutils-2.14


#### Build tools, round 2, now with less TCC
# At this stage we upgrade some tools that need an upgrade to build later parts,
#   as well as build some new tools we need.
# The remaining bootstrap binaries are rebuilt here, too.

# gnu-make-mesboot (3.82):
# This version can use multiple threads, greatly speeding up further builds.
# TODO: Can this be upgraded to 4.0 to support building modern glibc-2.31?
# Make 4.2/4.3 works flawlessly
rm -rf make-3.82
bzcat make-3.82.tar.bz2 | tar x
( cd make-3.82
    LIBS='-lc -lnss_files -lnss_dns -lresolv' ./configure \
        --build=i686-pc-linux-gnu
    make make
    install -Dm755 make /bin/make
)
rm -rf make-3.82

# From this point, multi-threaded make can be used.
export MAKEFLAGS="-j$NPROC"

# coreutils-mesboot0 (5.0):
# This is the oldest available version of coreutils, and it can't be built any
#   sooner...
rm -rf coreutils-5.0
bzcat coreutils-5.0.tar.bz2 | tar x
( cd coreutils-5.0
    # Tar-1.12 doesn't set the timestamps correctly...
    # Not fixing them causes erratic build results.
    touch aclocal.m4
    touch Makefile.in
    touch lib/Makefile.in
    touch lib/getdate.c
    touch src/Makefile.in
    touch src/dircolors.h
    touch src/wheel.h
    touch config.hin
    touch configure

    LIBS='-lc -lnss_files -lnss_dns -lresolv' ./configure \
        --build=i686-pc-linux-gnu \
        --prefix=/ \
        --disable-nls
    make -C lib
    make -C src
    make DESTDIR="$PWD/install" -C src install-exec
    install -v -Dm755 install/bin/* /bin/
)
rm -rf coreutils-5.0

# bash-mesboot (4.4):
# Finally an interactive shell!
rm -rf bash-4.4
zcat bash-4.4.tar.gz | tar x
( cd bash-4.4
    sed -e 's/;;$/;/' shell.c > /tmp/sed; mv /tmp/sed shell.c

    LIBS='-lc -lnss_files -lnss_dns -lresolv' ./configure \
        --disable-nls
    make bash
    install -Dm755 bash /bin/bash
    ln -sf bash /bin/sh
)
rm -rf bash-4.4

# (optional) At this point we can get rid of the remaining bootstrap binary...
#rm /bin/busybox /bin/busybox_unstripped
# Continue with bash (has tab completion :D):
# exec /bin/sh -l
# Entering the chroot after this point:
# ./bin/chroot . /bin/env -i PATH=/gcc2/bin:/bin /bin/sh -l

# tar-mesboot (1.22):
# Anything before tar 1.14 truncates the filenames when unpacking gcc-4.6.4
#   and gcc-4.9.4 for some odd reason.
# Tar-1.12 is also known to mess with the timestamps of several packages such
#   as coreutils and gawk.
# This may be removed if 1.14 can be built with TCC.
rm -rf tar-1.22
bzcat tar-1.22.tar.bz2 | tar x
( cd tar-1.22
    LIBS='-lc -lnss_files -lnss_dns -lresolv' ./configure \
        --disable-nls
    make -C lib
    make -C src
    install -Dm755 src/tar /bin/tar
)
rm -rf tar-1.22

# sed-mesboot (4.0.6):
# Required to build binutils-2.20.1a
# TODO: Can this be upgraded to 4.3 to support the -E option?
rm -rf sed-4.0.6
tar zxf sed-4.0.6.tar.gz
( cd sed-4.0.6
    ./configure --disable-nls
    make -C lib
    make -C sed
    install -Dm755 sed/sed /bin/sed
)
rm -rf sed-4.0.6

# gawk-mesboot (3.1.8):
# Upgrade required to build glibc-2.16.0
rm -rf gawk-3.1.8
tar jxf gawk-3.1.8.tar.bz2
( cd gawk-3.1.8
    ./configure \
        --build=i686-pc-linux-gnu \
        ac_cv_func_connect=no
    make gawk
    install -Dm755 gawk /bin/gawk
    ln -sf gawk /bin/awk
)
rm -rf gawk-3.1.8


#### Bootstrap C++, using gcc-4.6.4
export PATH=/gcc46/bin:/gcc2/bin:/bin
rm -rf /gcc46

# TODO: Reduce the amount of configure flags by only building specific targets
# gcc-mesboot1 (4.6.4):
rm -rf gcc-4.6.4
tar jxf gcc-core-4.6.4.tar.bz2
tar jxf gcc-g++-4.6.4.tar.bz2
( cd gcc-4.6.4
    tar jxf ../gmp-4.3.2.tar.bz2
    mv gmp-4.3.2 gmp
    tar jxf ../mpfr-2.4.2.tar.bz2
    mv mpfr-2.4.2 mpfr
    tar zxf ../mpc-1.0.3.tar.gz
    mv mpc-1.0.3 mpc

    # Build a compiler with /gcc2 as its sysroot, so it picks up the libraries
    #   from there without having to manually set environment variables, or
    #   patch the sources.
    # This just barely works because we're statically linking at this stage.
    sed -i -e '/^NATIVE_SYSTEM_HEADER_DIR =/s@/usr/include@/include@' \
        gcc/Makefile.in

    # Using --enable-bootstrap to avoid segfaulting later...
    # This causes the build to be the longest in the bootstrap, oh well.
    ./configure \
        --build=i686-pc-linux-gnu \
        --prefix=/gcc46 \
        --with-sysroot=/gcc2 \
        --with-local-prefix=/ \
        --with-stage1-libs=-lm \
        --disable-shared \
        \
        --disable-nls \
        --disable-decimal-float \
        --disable-libatomic \
        --disable-libcilkrts \
        --disable-libgomp \
        --disable-libitm \
        --disable-libmudflap \
        --disable-libquadmath \
        --disable-libsanitizer \
        --disable-libssp \
        --disable-libvtv \
        --disable-lto \
        --disable-lto-plugin \
        --disable-multilib \
        --disable-plugin \
        --disable-threads \
        --enable-threads=single \
        --disable-libstdcxx-pch \
        --disable-build-with-cxx
    make
    make install
)
rm -rf gcc-4.6.4


#### Create "final" bootstrap toolchain, gcc-4.9.4, binutils-2.20.1a, glibc-2.16.0
# This toolchain is the minimum requirement to build a current GCC, as it
#   fully supports C11 and C++11.
# Additionally, this toolchain is built with support for dynamic linking.

export PATH=/bootstrap/bin:/gcc46/bin:/gcc2/bin:/bin
rm -rf /bootstrap

# binutils-mesboot (2.20.1a):
rm -rf binutils-2.20.1
tar jxf binutils-2.20.1a.tar.bz2
( cd binutils-2.20.1
    ./configure \
        --build=i686-pc-linux-gnu \
        --prefix=/bootstrap \
        --with-sysroot \
        --with-lib-path=/bootstrap/lib \
        --disable-shared \
        --disable-nls \
        --disable-werror
    make
    make install
)
rm -rf binutils-2.20.1

export PATH=/bootstrap/bin:/gcc46/bin:/bin

# glibc-mesboot (2.16.0):
cp -ar linux-headers/include /bootstrap/
rm -rf glibc-2.16.0
tar jxf glibc-2.16.0.tar.bz2
( cd glibc-2.16.0
    patch -p1 -i ../glibc-boot-2.16.0.patch

    # This can't be rebuilt with the final gcc and glibc, for some reason
    # Possibly the configure flags aren't suitable?
    mkdir build && cd build
    CC='/gcc46/bin/gcc -DBOOTSTRAP_GLIBC=1 -L/gcc2/lib' ../configure \
        --build=i686-pc-linux-gnu \
        --prefix=/bootstrap \
        --with-headers=/bootstrap/include \
        --disable-multi-arch \
        --enable-static-nss \
        --with-pthread \
        --without-cvs \
        --without-gd \
        --enable-add-ons=nptl \
        libc_cv_predef_stack_protector=no \
        libc_cv_ssp=no \
        libc_cv_friendly_stddef=yes
    make "$PWD/sysd-sorted"
    sed -i -e 's/ sunrpc//' -e 's/ nis//' sysd-sorted
    make

    # `sbindir` isn't picked up by config.make.in, so the configure flag is useless
    mkdir -p /bootstrap/etc
    make install
)
rm -rf glibc-2.16.0

# gcc-mesboot (4.9.4):
rm -rf gcc-4.9.4
tar jxf gcc-4.9.4.tar.bz2
( cd gcc-4.9.4
    tar jxf ../gmp-4.3.2.tar.bz2
    mv gmp-4.3.2 gmp
    tar jxf ../mpfr-2.4.2.tar.bz2
    mv mpfr-2.4.2 mpfr
    tar zxf ../mpc-1.0.3.tar.gz
    mv mpc-1.0.3 mpc

    # The previous setup to set the library/include path with --with-sysroot
    #   doesn't work when you throw dynamic linking into the mix and you're not
    #   purely cross-compiling (we want to run resulting binaries as-is).
    # So, instead, we patch the sources.
    # Thankfully, --with-native-system-header-dir was introduced, so we don't
    #   need to patch STANDARD_INCLUDE_DIR to do this.
cat >> gcc/config/i386/linux.h << 'EOF'
#undef GLIBC_DYNAMIC_LINKER
#define GLIBC_DYNAMIC_LINKER "/bootstrap/lib/ld-linux.so.2"
#define STANDARD_STARTFILE_PREFIX_1 "/bootstrap/lib/"
#define STANDARD_STARTFILE_PREFIX_2 ""
EOF

    ./configure \
        --build=i686-pc-linux-gnu \
        --prefix=/bootstrap \
        --with-native-system-header-dir=/bootstrap/include \
        --with-local-prefix=/bootstrap \
        --with-host-libstdcxx=-lsupc++ \
        --enable-languages=c,c++ \
        --disable-bootstrap \
        \
        --disable-nls \
        --disable-decimal-float \
        --disable-libatomic \
        --disable-libcilkrts \
        --disable-libgomp \
        --disable-libitm \
        --disable-libmudflap \
        --disable-libquadmath \
        --disable-libsanitizer \
        --disable-libssp \
        --disable-libvtv \
        --disable-lto \
        --disable-lto-plugin \
        --disable-multilib \
        --disable-plugin \
        --disable-threads \
        --enable-threads=single \
        --disable-libstdcxx-pch \
        --disable-build-with-cxx
    make
    make install
)
rm -rf gcc-4.9.4


#### The end
# With the bootstrap toolchain fully built, apply some finishing touches by
#   cleaning stuff up.
export PATH=/bootstrap/bin:/bin

# findutils (4.6.0):
# This one is completely optional, as it's not required for a bootstrap.
# However, a ton of scripts you'll probably use to further bootstrap will
#   probably need it.
# Busybox/linux requiring this to build is a good enough reason to put it here.
rm -rf findutils-4.6.0
tar zxf findutils-4.6.0.tar.gz
( cd findutils-4.6.0
    ./configure \
        --build=i686-pc-linux-gnu \
        --disable-nls
    make -C gl
    make -C lib
    make -C find
    make -C xargs
    install -Dm755 find/find /bin/find
    install -Dm755 xargs/xargs /bin/xargs
)
rm -rf findutils-4.6.0

# Entering chroot before cleanup:
# ./bin/chroot . /bin/env -i PATH=/bootstrap/bin:/bin /bin/sh -l

# Move binaries
rm -f /bin/busybox /bin/busybox_unstripped
mv /bin/* /bootstrap/bin/
hash -r  # a ton of binaries just moved
ln -sf ../bootstrap/bin/bash /bin/bash
ln -sf bash /bin/sh

# Strip everything (saves hundreds of MB)
find /bootstrap/lib -type f -name '*.a' | xargs strip --strip-debug || true
find /bootstrap/lib -type f -name '*.so*' | xargs strip --strip-unneeded || true
find /bootstrap/bin /bootstrap/sbin /bootstrap/libexec -type f | xargs strip --strip-all || true
cp /bootstrap/bin/strip /strip
strip -s /strip
mv /strip /bootstrap/bin/strip

# Clean up
#rm -rf /gcc46 /gcc2 /tcc /mes
rm -rf /bootstrap/share /bootstrap/var /bootstrap/etc
rm -f /bootstrap/lib/*.la /bootstrap/lib/libstdc++.so.*-gdb.py

# Back it up
cd /
find bootstrap bin/sh bin/bash -type f -o -type l | LC_ALL=C sort | xargs tar --mtime=@0 --numeric-owner --owner=0 --group=0 -cf bootstrap.tar
gzip -nv bootstrap.tar

# Entering chroot after cleanup:
# ./bootstrap/bin/chroot . /bootstrap/bin/env -i PATH=/bootstrap/bin /bootstrap/bin/sh -l