build-telemetry-ffi.sh

#!/usr/bin/env bash

# Copyright 2021-Present Datadog, Inc. https://www.datadoghq.com/
# SPDX-License-Identifier: Apache-2.0

set -eu

destdir="$1"

mkdir -v -p "$destdir/include/datadog" "$destdir/lib/pkgconfig" "$destdir/cmake"

version=$(awk -F\" '$1 ~ /^version/ { print $2 }' < ddtelemetry-ffi/Cargo.toml)
target="$(rustc -vV | awk '/^host:/ { print $2 }')"
shared_library_suffix=".so"
static_library_suffix=".a"
library_prefix="lib"
remove_rpath=0
fix_macos_rpath=0

# Rust provides this note about the link libraries:
# note: Link against the following native artifacts when linking against this
# static library. The order and any duplication can be significant on some
# platforms.
#
# We've decided to strip out -lgcc_s because if it's provided then it will
# always make it into the final runtime dependencies, even if -static-libgcc is
# provided. At least on Alpine, libgcc_s may not even exist in the users'
# images, so -static-libgcc is recommended there.
case "$target" in
    "x86_64-alpine-linux-musl"|"aarch64-alpine-linux-musl")
        expected_native_static_libs=" -lssp_nonshared -lgcc_s -lc"
        native_static_libs=" -lssp_nonshared -lc"
        # on alpine musl, Rust adds some weird runpath to cdylibs
        remove_rpath=1
        ;;

    "x86_64-apple-darwin"|"aarch64-apple-darwin")
        expected_native_static_libs=" -framework Security -framework CoreFoundation -liconv -lSystem -lresolv -lc -lm -liconv"
        native_static_libs="${expected_native_static_libs}"
        shared_library_suffix=".dylib"
        # fix usage of library in macos via rpath
        fix_macos_rpath=1
        ;;

    "x86_64-unknown-linux-gnu"|"aarch64-unknown-linux-gnu")
        expected_native_static_libs=" -ldl -lrt -lpthread -lgcc_s -lc -lm -lrt -lpthread -lutil -ldl -lutil"
        native_static_libs=" -ldl -lrt -lpthread -lc -lm -lrt -lpthread -lutil -ldl -lutil"
        ;;

    "x86_64-pc-windows-msvc")
        expected_native_static_libs="" # I don't know what to expect
        native_static_libs="" # I don't know what to expect
        shared_library_suffix=".dll"
        static_library_suffix=".lib"
        library_prefix=""
        ;;

    *)
        >&2 echo "Unknown platform '${target}'"
        exit 1
        ;;
esac

cp -v LICENSE LICENSE-3rdparty.yml NOTICE "$destdir/"

export RUSTFLAGS="${RUSTFLAGS:- -C relocation-model=pic}"

datadog_telemetry_ffi="ddtelemetry-ffi"
echo "Building the ${datadog_telemetry_ffi} crate (may take some time)..."
DESTDIR="$destdir" cargo build --package="${datadog_telemetry_ffi}" --release --target "${target}"

# Remove _ffi suffix when copying
shared_library_name="${library_prefix}ddtelemetry_ffi${shared_library_suffix}"
shared_library_rename="${library_prefix}ddtelemetry${shared_library_suffix}"

static_library_name="${library_prefix}ddtelemetry_ffi${static_library_suffix}"
static_library_rename="${library_prefix}ddtelemetry${static_library_suffix}"

cp -v "target/${target}/release/${shared_library_name}" "$destdir/lib/${shared_library_rename}"
cp -v "target/${target}/release/${static_library_name}" "$destdir/lib/${static_library_rename}"

shared_library_name="${shared_library_rename}"
static_library_name="${static_library_rename}"

if [[ "$remove_rpath" -eq 1 ]]; then
    patchelf --remove-rpath "$destdir/lib/${shared_library_name}"
fi

if [[ "$fix_macos_rpath" -eq 1 ]]; then
    install_name_tool -id @rpath/${shared_library_name} "$destdir/lib/${shared_library_name}"
fi

# objcopy might not be available on macOS
if command -v objcopy > /dev/null && [[ "$target" != "x86_64-pc-windows-msvc" ]]; then
    # Remove .llvmbc section which is not useful for clients
    objcopy --remove-section .llvmbc "$destdir/lib/${static_library_name}"

    # Ship debug information separate from shared library, so that downstream packages can selectively include it
    # https://sourceware.org/gdb/onlinedocs/gdb/Separate-Debug-Files.html
    objcopy --only-keep-debug "$destdir/lib/$shared_library_name" "$destdir/lib/$shared_library_name.debug"
    strip -S "$destdir/lib/$shared_library_name"
    objcopy --add-gnu-debuglink="$destdir/lib/$shared_library_name.debug" "$destdir/lib/$shared_library_name"
fi

echo "Checking that native-static-libs are as expected for this platform..."
cd ddtelemetry-ffi
actual_native_static_libs="$(cargo rustc --release --target "${target}" -- --print=native-static-libs 2>&1 | awk -F ':' '/note: native-static-libs:/ { print $3 }')"
echo "Actual native-static-libs:${actual_native_static_libs}"
echo "Expected native-static-libs:${expected_native_static_libs}"

# Compare unique elements between expected and actual native static libs.
# If actual libs is different from expected libs but still a subset of expected libs
# (ie. we will overlink compared to what is actually needed), this is not considered as an error.
# Raise an error only if some libs are in actual libs but not in expected libs.

# trim leading and trailing spaces, then split the string on " -" by inserting new lines and sort lines while removing duplicates
unique_expected_libs=$(echo "$expected_native_static_libs "| awk '{ gsub(/^[ \t]+|[ \t]+$/, "");gsub(/ +-/,"\n-")};1' | sort -u)
unique_libs=$(echo "$actual_native_static_libs "| awk '{ gsub(/^[ \t]+|[ \t]+$/, "");gsub(/ +-/,"\n-")};1' | sort -u)

unexpected_native_libs=$(comm -13 <(echo "$unique_expected_libs") <(echo "$unique_libs"))
if [ -n "$unexpected_native_libs" ]; then
    echo "Error - More native static libraries are required for linking than expected:" 1>&2
    echo "$unexpected_native_libs" 1>&2
    exit 1
fi
cd -

echo "Building tools"
cargo build --package tools --bins

echo "Generating $destdir/include/libdatadog headers..."
./target/debug/dedup_headers "${destdir}/include/datadog/common.h" "${destdir}/include/datadog/telemetry.h"

echo "Done."