tools: add riscv64 host setup script

tools/buildutils/setup-riscv64-host.sh

@@ -0,0 +1,145 @@
+#!/usr/bin/env bash
+
+# Copyright (C) 2025 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Set up a riscv64 Debian/Ubuntu host for building android-cuttlefish.
+#
+# On x86_64 and aarch64, prebuilt binaries exist for bazel, cargo-bazel,
+# and other tools.  On riscv64 we must build some from source.
+# This script handles everything automatically.
+
+set -e
+
+if [ "$(uname -m)" != "riscv64" ]; then
+  echo "This script is intended for riscv64 hosts only." >&2
+  exit 1
+fi
+
+echo "Installing riscv64 build dependencies for android-cuttlefish..."
+
+sudo apt-get update
+
+# General build tools
+sudo apt-get install -y \
+  build-essential \
+  git \
+  openjdk-21-jdk \
+  pkg-config \
+  python3 \
+  zip \
+  unzip \
+  wget
+
+# packages needed by debuild
+sudo apt-get install -y \
+  devscripts \
+  config-package-dev \
+  debhelper-compat \
+  equivs
+
+# LLVM/Clang toolchain - used by Bazel via toolchains_llvm.
+# libc++ is required because toolchains_llvm defaults to builtin-libc++
+# and expects headers at /usr/lib/llvm-19/include/c++/v1/.
+# libclang-rt provides compiler-rt builtins (libclang_rt.builtins.a)
+# needed by the linker.
+sudo apt-get install -y \
+  clang-19 \
+  lld-19 \
+  libc++-19-dev \
+  libc++abi-19-dev \
+  libclang-rt-19-dev
+
+# Debian's clang-rt package uses the legacy layout:
+#   lib/clang/19/lib/linux/libclang_rt.builtins-riscv64.a
+# but toolchains_llvm expects the per-target layout:
+#   lib/clang/19/lib/riscv64-unknown-linux-gnu/libclang_rt.builtins.a
+# Create a symlink to bridge the two if needed.
+LEGACY_RT="/usr/lib/llvm-19/lib/clang/19/lib/linux/libclang_rt.builtins-riscv64.a"
+TARGET_DIR="/usr/lib/llvm-19/lib/clang/19/lib/riscv64-unknown-linux-gnu"
+TARGET_RT="${TARGET_DIR}/libclang_rt.builtins.a"
+if [ -f "$LEGACY_RT" ] && [ ! -e "$TARGET_RT" ]; then
+  echo "Creating clang-rt per-target symlink..."
+  sudo mkdir -p "$TARGET_DIR"
+  sudo ln -sf "$LEGACY_RT" "$TARGET_RT"
+elif [ -e "$TARGET_RT" ]; then
+  echo "clang-rt per-target layout already exists, skipping symlink."
+else
+  echo "WARNING: libclang-rt-19-dev installed but $LEGACY_RT not found." >&2
+  echo "Your distro may use a different layout. You may need to manually create:" >&2
+  echo "  $TARGET_RT -> <path to libclang_rt.builtins for riscv64>" >&2
+fi
+
+# Rust toolchain
+sudo apt-get install -y rustc cargo
+
+# cargo-bazel: no prebuilt riscv64 binary; build from rules_rust source.
+# cargo-bazel is not published on crates.io — it's an internal tool in
+# rules_rust's crate_universe directory.  Must match the rules_rust version
+# used by the project (currently 0.68.1).
+RULES_RUST_VERSION=0.68.1
+CARGO_BAZEL_DIR="${HOME}/.local/cargo-bazel-rules-rust-${RULES_RUST_VERSION}"
+CARGO_BAZEL_BIN="${CARGO_BAZEL_DIR}/bin/cargo-bazel"
+if [ ! -x "${CARGO_BAZEL_BIN}" ]; then
+  echo "Building cargo-bazel from rules_rust ${RULES_RUST_VERSION} source..."
+  tmpdir="$(mktemp -d)"
+  trap "rm -rf $tmpdir" EXIT
+  pushd "$tmpdir"
+  wget -q "https://github.com/bazelbuild/rules_rust/archive/refs/tags/${RULES_RUST_VERSION}.tar.gz"
+  tar xzf "${RULES_RUST_VERSION}.tar.gz"
+  cargo install --path "rules_rust-${RULES_RUST_VERSION}/crate_universe" \
+    --root "${CARGO_BAZEL_DIR}"
+  popd
+  echo "cargo-bazel installed to ${CARGO_BAZEL_BIN}"
+else
+  echo "cargo-bazel already installed at ${CARGO_BAZEL_BIN}"
+fi
+
+# Bazel: no official riscv64 binary; build from source if not installed.
+BAZEL_VERSION=8.5.1
+if command -v bazel &>/dev/null; then
+  echo "Bazel already installed: $(bazel --version)"
+else
+  echo "Building Bazel ${BAZEL_VERSION} from source (this takes 30-60 minutes)..."
+  tmpdir="$(mktemp -d)"
+  trap "rm -rf $tmpdir" EXIT
+  pushd "$tmpdir"
+  wget -q "https://github.com/bazelbuild/bazel/releases/download/${BAZEL_VERSION}/bazel-${BAZEL_VERSION}-dist.zip"
+  unzip -q "bazel-${BAZEL_VERSION}-dist.zip"
+
+  # Fix locale-dependent sorting mismatch: Bazel's bootstrap compile.sh
+  # uses `sort` and `comm` on file lists.  When the locale's collation
+  # order differs between the two commands, `comm` rejects the input as
+  # unsorted and exits non-zero (fatal under `set -e`).  Forcing LC_ALL=C
+  # ensures both tools agree on byte-order sorting.
+  sed -i \
+    -e 's#| sort >#| LC_ALL=C sort >#g' \
+    -e 's#comm -#LC_ALL=C comm -#g' \
+    scripts/bootstrap/compile.sh
+
+  env EXTRA_BAZEL_ARGS="--tool_java_runtime_version=local_jdk" bash ./compile.sh
+  sudo cp output/bazel /usr/local/bin/bazel
+  popd
+  echo "Bazel ${BAZEL_VERSION} installed to /usr/local/bin/bazel"
+fi
+
+CARGO_BAZEL_SHA256="$(sha256sum "${CARGO_BAZEL_BIN}" | cut -d' ' -f1)"
+echo ""
+echo "riscv64 host setup complete."
+echo ""
+echo "Before building, set the cargo-bazel environment variables:"
+echo "  export CARGO_BAZEL_GENERATOR_URL=\"file://${CARGO_BAZEL_BIN}\""
+echo "  export CARGO_BAZEL_GENERATOR_SHA256=\"${CARGO_BAZEL_SHA256}\""
+
+echo "All done!"