llvm-cov.sh

set -ex

main() {
    rustup default stable
    rustup component add rust-src

    rm -rf hello
    cargo new --bin hello

    cd hello
    build_libprofiler

    RUSTFLAGS="-C passes=insert-gcov-profiling" cargo rustc -- \
             -C link-arg=-lprofiler \
             -C link-arg=-L$(pwd)

    target/debug/hello

    # OUTPUT main.gcda main.gcno
    ls *.gc*
}

build_libprofiler() {
    local sources=(
        GCDAProfiling.c
        InstrProfiling.c
        InstrProfilingBuffer.c
        InstrProfilingFile.c
        InstrProfilingMerge.c
        InstrProfilingMergeFile.c
        InstrProfilingPlatformLinux.c
        InstrProfilingRuntime.cc
        InstrProfilingUtil.c
        InstrProfilingValue.c
        InstrProfilingWriter.c
    )
    local src_dir=$(rustc --print sysroot)/lib/rustlib/src/rust/src/compiler-rt/lib/profile

    local td=$(mktemp -d)

    for source in ${sources[@]}; do
        gcc \
            -fPIC \
            -DVISIBILITY_HIDDEN \
            -c \
            -ffreestanding \
            -fno-builtin \
            -fomit-frame-pointer \
            -fvisibility=hidden \
            $src_dir/$source \
            -o $td/${source%.*}.o
    done

    local objs=( ${sources[@]/%.*/.o} )

    ar crus libprofiler.a ${objs[@]/#/$td/}

    rm -rf $td
}

main