#!/usr/bin/env bash
# SPDX-License-Identifier: Apache-2.0
# Copyright (C) 2021 Arm Limited or its affiliates and Contributors. All rights reserved.

[[ "$TRACE" ]] && set -x
set -euo pipefail

awk_inplace() {
    for LAST in "$@"; do :; done
    TMP="$(mktemp)"
    awk "$@" > "$TMP"
    mv "$TMP" "$LAST"
}

patch_clang_version() {
    # Here we patch the clang version to include the commit SHA by defining LLVM_REVISION and CLANG_REVISION
    # We insert the #defines after the last #include (which seems reasonably safe, but could be confused by an #if #include #endif for example
    git checkout -- ../clang/lib/Basic/Version.cpp
    awk_inplace -c -v commit="\"$1\"" 'FNR==NR{ if (/#include/) p=NR; next} 1; FNR==p{ print "#define LLVM_REVISION " commit; print "#define CLANG_REVISION LLVM_REVISION"; }' ../clang/lib/Basic/Version.cpp ../clang/lib/Basic/Version.cpp
}

patch_llvm_version() {
    # We do a similar thing for LLVM tools -- define LLVM_VERSION_INFO manually
    git checkout -- ../llvm/lib/Support/CommandLine.cpp
    awk_inplace -c -v commit="\"$1\"" 'FNR==NR{ if (/#include/) p=NR; next} 1; FNR==p{ print "#define LLVM_VERSION_INFO " commit }' ../llvm/lib/Support/CommandLine.cpp ../llvm/lib/Support/CommandLine.cpp
}

create_link_script() {
    # Save all link lines as functions
    ninja -t rules | grep 'CXX_EXECUTABLE_LINKER\|CXX_STATIC_LIBRARY' \
        | grep -Ev '\-test|\-fuzzer' \
        | xargs ninja -t compdb \
        | compdb2line build-lines-with-output \
        | awk '{print $1"(){"; $1=""; print $0; print "}"}'
    # Save all symlinks in bin/
    find ./bin/ -maxdepth 1 -type l | while read -r SYMLINK; do
        LINK_NAME="$(basename "$SYMLINK")"
        LINK_TARGET="$(readlink "$SYMLINK")"
        echo "$LINK_NAME(){ $LINK_TARGET; ln -sf $LINK_TARGET $SYMLINK; }"
    done
    cat << EOF
mkdir ./bin |& true
if [ \$# -eq 0 ]; then
    compgen -A function | while read -r FUNC; do { "\$FUNC" & } done
else
    for ARG in "\$@"; do { "\$ARG" & } done
fi
wait
EOF
}

main() {
    patch_clang_version "$(git rev-parse HEAD)"
    # patch_llvm_version invalidates llvm-tblgen and causes builds to run slower!
    # patch_llvm_version "$(git rev-parse HEAD)"

    CCACHE_FILECLONE=1 CCACHE_SLOPPINESS=time_macros ninja

    create_link_script > ./link.sh
}

main "$@"