build_ffi.sh

#!/bin/bash

#
# Copyright 2020-2021 Signal Messenger, LLC.
# SPDX-License-Identifier: AGPL-3.0-only
#

set -euo pipefail

SCRIPT_DIR=$(dirname "$0")
cd "${SCRIPT_DIR}"/..
. bin/build_helpers.sh

usage() {
  cat >&2 <<END
Usage: $(basename "$0") [options]

Options:
  -d -- debug build (default)
  -r -- release build
  -v -- verbose build

  --generate-ffi     -- regenerate ffi headers
  --verify-ffi       -- verify that ffi headers are up to date
  --build-std        -- use Cargo's -Zbuild-std to compile for a tier 3 target
  --debug-level-logs -- include log levels below INFO (default for debug builds)

Use CARGO_BUILD_TARGET for cross-compilation (such as for iOS).
END
}

RELEASE_BUILD=
VERBOSE=
SHOULD_CBINDGEN=
CBINDGEN_VERIFY=
BUILD_STD=
DEBUG_LEVEL_LOGS=

while [ "${1:-}" != "" ]; do
  case $1 in
    -d | --debug )
      RELEASE_BUILD=
      ;;
    -r | --release )
      RELEASE_BUILD=1
      ;;
    -v | --verbose )
      VERBOSE=1
      ;;
    --generate-ffi )
      SHOULD_CBINDGEN=1
      ;;
    --verify-ffi )
      SHOULD_CBINDGEN=1
      CBINDGEN_VERIFY=1
      ;;
    --build-std)
      BUILD_STD=1
      ;;
    --debug-level-logs)
      DEBUG_LEVEL_LOGS=1
      ;;
    -h | --help )
      usage
      exit
      ;;
    * )
      usage
      exit 2
  esac
  shift
done

check_rust "$BUILD_STD"

# Fetch dependencies first, so we can use them in computing later options.
cargo fetch

export CARGO_PROFILE_RELEASE_DEBUG=1 # enable line tables

if [[ -n "${CARGO_BUILD_TARGET:-}" ]]; then
  # Avoid overriding RUSTFLAGS for host builds, because that resets the incremental build.
  RUSTFLAGS="--cfg aes_armv8 ${RUSTFLAGS:-}" # Enable ARMv8 cryptography acceleration when available
  RUSTFLAGS="--cfg tokio_unstable ${RUSTFLAGS:-}" # Access tokio's unstable metrics
  RUSTFLAGS="$(rust_remap_path_options) ${RUSTFLAGS:-}" # Strip absolute paths
  export RUSTFLAGS
fi

if [[ "${CARGO_BUILD_TARGET:-}" =~ -ios(-sim|-macabi)?$ ]]; then
  export IPHONEOS_DEPLOYMENT_TARGET=15

  # Use full LTO to reduce binary size
  export CARGO_PROFILE_RELEASE_LTO=fat
  export CFLAGS="-flto=full ${CFLAGS:-}"
  export CXXFLAGS="-flto=full ${CXXFLAGS:-}"

  # Use small BoringSSL curve tables to reduce binary size
  export CFLAGS="-DOPENSSL_SMALL ${CFLAGS:-}"
  export CXXFLAGS="-DOPENSSL_SMALL ${CXXFLAGS:-}"
fi

# Work around cc crate bug with Catalyst targets
export CFLAGS_aarch64_apple_ios_macabi="--target=arm64-apple-ios-macabi ${CFLAGS:-}"
export CFLAGS_x86_64_apple_ios_macabi="--target=x86_64-apple-ios-macabi ${CFLAGS:-}"

FEATURES=()
if [[ "${CARGO_BUILD_TARGET:-}" != "aarch64-apple-ios" ]]; then
  FEATURES+=("libsignal-bridge-testing")
fi

check_cbindgen() {
  if ! command -v cbindgen > /dev/null; then
    echo 'error: cbindgen not found in PATH' >&2
    if command -v cargo > /dev/null; then
      echo 'note: get it by running' >&2
      printf "\n\t%s\n\n" "cargo +stable install cbindgen" >&2
    fi
    exit 1
  fi
}

if [[ -n "${DEVELOPER_SDK_DIR:-}" ]]; then
  # Assume we're in Xcode, which means we're probably cross-compiling.
  # In this case, we need to add an extra library search path for build scripts and proc-macros,
  # which run on the host instead of the target.
  # (macOS Big Sur does not have linkable libraries in /usr/lib/.)
  export LIBRARY_PATH="${DEVELOPER_SDK_DIR}/MacOSX.sdk/usr/lib:${LIBRARY_PATH:-}"
fi

if [[ -n "${BUILD_STD:-}" ]]; then
  RUSTUP_TOOLCHAIN=${RUSTUP_TOOLCHAIN:-$(cat ./rust-toolchain)}
  if ! rustup "+${RUSTUP_TOOLCHAIN}" component list --installed | grep -q rust-src; then
    echo 'error: rust-src component not installed' >&2
    echo 'note: get it by running' >&2
    printf "\n\t%s\n\n" "rustup +${RUSTUP_TOOLCHAIN} component add rust-src" >&2
    exit 1
  fi
fi

if [[ -z "${DEBUG_LEVEL_LOGS:-}" ]]; then
  FEATURES+=("log/release_max_level_info")
fi

echo_then_run cargo build -p libsignal-ffi ${RELEASE_BUILD:+--release} ${VERBOSE:+--verbose} ${CARGO_BUILD_TARGET:+--target $CARGO_BUILD_TARGET} ${FEATURES:+--features "${FEATURES[*]}"} ${BUILD_STD:+-Zbuild-std}

if [[ -n "${RELEASE_BUILD:-}" && -z "${DEBUG_LEVEL_LOGS:-}" ]]; then
  # See libsignal-ffi's logging.rs.
  if grep -q -- '-LEVEL LOGS ENABLED' "${CARGO_TARGET_DIR:-target}/${CARGO_BUILD_TARGET:-}/release/libsignal_ffi.a"; then
    echo 'error: debug-level logs found in build that should not have them!' >&2
    exit 2
  fi
fi

FFI_HEADER_PATH=swift/Sources/SignalFfi/signal_ffi.h
FFI_TESTING_HEADER_PATH=swift/Sources/SignalFfi/signal_ffi_testing.h

if [[ -n "${SHOULD_CBINDGEN}" ]]; then
  check_cbindgen

  echo "Checking cbindgen version"
  VERSION=$(cbindgen --version)
  echo "Found $VERSION"

  EXPECTED_VERSION=$(cat .cbindgen-version)
  if [ "$VERSION" != "cbindgen $EXPECTED_VERSION" ]; then
    echo "warning: this script expects cbindgen version $EXPECTED_VERSION, but $VERSION is installed" >&2
  fi

  if [[ -n "${CBINDGEN_VERIFY}" ]]; then
    echo diff -u "${FFI_HEADER_PATH}" "<(cbindgen -q ${RELEASE_BUILD:+--profile release} rust/bridge/ffi)"
    if ! diff -u "${FFI_HEADER_PATH}"  <(cbindgen -q ${RELEASE_BUILD:+--profile release} rust/bridge/ffi); then
      echo
      echo 'error: signal_ffi.h not up to date; run' "$0" '--generate-ffi' >&2
      exit 1
    fi
    echo diff -u "${FFI_TESTING_HEADER_PATH}" "<(cbindgen -q ${RELEASE_BUILD:+--profile release} rust/bridge/shared/testing --config rust/bridge/ffi/cbindgen-testing.toml)"
    if ! diff -u "${FFI_TESTING_HEADER_PATH}"  <(cbindgen -q ${RELEASE_BUILD:+--profile release} rust/bridge/shared/testing --config rust/bridge/ffi/cbindgen-testing.toml); then
      echo
      echo 'error: signal_ffi_testing.h not up to date; run' "$0" '--generate-ffi' >&2
      exit 1
    fi
  else
    echo cbindgen ${RELEASE_BUILD:+--profile release} -o "${FFI_HEADER_PATH}" rust/bridge/ffi
    # Use sed to ignore irrelevant cbindgen warnings.
    # ...and then disable the shellcheck warning about literal backticks in single-quotes
    # shellcheck disable=SC2016
    cbindgen ${RELEASE_BUILD:+--profile release} -o "${FFI_HEADER_PATH}" rust/bridge/ffi 2>&1 |
      sed '/WARN: Missing `\[defines\]` entry for `feature = "ffi"` in cbindgen config\./ d' >&2

    echo cbindgen ${RELEASE_BUILD:+--profile release} -o "${FFI_TESTING_HEADER_PATH}" rust/bridge/shared/testing --config rust/bridge/ffi/cbindgen-testing.toml
    # shellcheck disable=SC2016
    cbindgen ${RELEASE_BUILD:+--profile release} -o "${FFI_TESTING_HEADER_PATH}" rust/bridge/shared/testing --config rust/bridge/ffi/cbindgen-testing.toml 2>&1 |
      sed '/WARN: Missing `\[defines\]` entry for `feature = "ffi"` in cbindgen config\./ d' >&2
  fi
fi