# Cross compile an llvm-mingw toolchain for windows.
#
# This needs to be built with --build-arg BASE=<image>, where image is the name
# of a docker image that contains a working llvm-mingw cross compiler
# from a similar enough version.
#
# This builds LLVM and all other build tools that need to run on the target
# platform, but just copies over the runtime libraries from the existing
# toolchain in the base docker image.

ARG BASE=mstorsjo/llvm-mingw:dev
FROM $BASE

RUN apt-get update -qq && \
    apt-get install -qqy zip && \
    apt-get clean -y && \
    rm -rf /var/lib/apt/lists/*

ARG CROSS_ARCH=x86_64
ENV CROSS_TOOLCHAIN_PREFIX=/opt/llvm-mingw-$CROSS_ARCH

ENV EXEEXT=.exe
ENV HOST=$CROSS_ARCH-w64-mingw32

ARG CORES=4

COPY build-llvm.sh .
RUN ./build-llvm.sh $CROSS_TOOLCHAIN_PREFIX
COPY strip-llvm.sh .
RUN ./strip-llvm.sh $CROSS_TOOLCHAIN_PREFIX

ARG TOOLCHAIN_ARCHS="i686 x86_64 armv7 aarch64"

COPY build-mingw-w64.sh ./
RUN ./build-mingw-w64.sh $CROSS_TOOLCHAIN_PREFIX --skip-include-triplet-prefix

COPY wrappers/*.sh wrappers/*.c ./wrappers/
COPY install-wrappers.sh .
RUN ./install-wrappers.sh $CROSS_TOOLCHAIN_PREFIX

COPY prepare-cross-toolchain.sh .
RUN ./prepare-cross-toolchain.sh $TOOLCHAIN_PREFIX $CROSS_TOOLCHAIN_PREFIX $CROSS_ARCH

# Cheating: Build binutils for an x86 target and take strip and objcopy
# from there. The wrapper script can use them for any arch.
RUN wget -q https://ftp.gnu.org/gnu/binutils/binutils-2.31.1.tar.xz && \
    tar -Jxf binutils-2.31.1.tar.xz && \
    cd binutils-2.31.1 && \
    ./configure --host=$HOST --target=x86_64-w64-mingw32 --prefix=/opt/binutils LDFLAGS="-Wl,-s" && \
    make -j$CORES && \
    make install && \
    cp /opt/binutils/x86_64-w64-mingw32/bin/objcopy.exe $CROSS_TOOLCHAIN_PREFIX/bin/binutils-objcopy.exe && \
    cp /opt/binutils/x86_64-w64-mingw32/bin/strip.exe $CROSS_TOOLCHAIN_PREFIX/bin/binutils-strip.exe
ARG TAG
RUN ln -s $CROSS_TOOLCHAIN_PREFIX llvm-mingw && \
    zip -9r /llvm-mingw-$TAG$CROSS_ARCH.zip llvm-mingw