build/resultstore/rsninja.sh

#!/bin/bash
# Copyright 2025 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

# rsninja.sh (this script) is a drop-in replacement for a ninja binary.
#
# rs-ninja.sh (from rsclient package) enables ResultStore features in ninja
#   when it detects RSPROXY_FIFO in the environment (any intermediate
#   ninja wrappers should take care to pass-through this variable).
#   Otherwise, it falls back to the original ninja invocation.

# Using this script as a level of indirection allows the communication
# mechanism between rsproxy-wrap.sh and rs-ninja.sh (from rsclient) to
# change without breaking the build.

# See also rs-sub-ninja.sh, which a suitable drop-in replacement
# that includes rsproxy-wrap.sh.
# Use rsninja.sh when there is a need to insert other wrappers
# between rsproxy-wrap.sh and ninja (like in `fx build`).

set -euo pipefail

readonly SCRIPT_DIR="$(dirname "${BASH_SOURCE[0]}")"

# Get the HOST_PLATFORM for the prebuilt path.
# Sourcing platform.sh requires FUCHSIA_DIR to be set.
readonly FUCHSIA_DIR="$(readlink -f "$SCRIPT_DIR/../..")"
source "${FUCHSIA_DIR}/tools/devshell/lib/platform.sh"

# rsclient install path is set in manifests/prebuilts
readonly PREBUILT_RSCLIENT_DIR="${FUCHSIA_DIR}/prebuilt/rsclient/$HOST_PLATFORM"
readonly wrapper="$PREBUILT_RSCLIENT_DIR/bin/rs-ninja.sh"
readonly ninja_bin="$PREBUILT_NINJA"

# The RSPROXY_FIFO check is redundant with the rs-ninja.sh wrapper script, but
# harmless.  Checking here lets us bypass unnecessary setup.
if [[ -z "${RSPROXY_FIFO+x}" ]]
then exec "$ninja_bin" "$@"
  # no return
fi
if [ ! -x "$wrapper" ]
then
  echo "Error: $wrapper is not executable, falling back to using $ninja_bin."
  exec "$ninja_bin" "$@"
  # no return
fi

# Proceed with using ResultStore features.
function new_uuid() {
  "${PREBUILT_PYTHON3}" -S -c 'import uuid; print(uuid.uuid4())'
}

# Give sub-ninja a new invocation id.
# This is different from FX_BUILD_UUID.
# LINT.IfChange(related_invocations_env_vars)
#   (Keep names of RESULTSTORE_* environment variables in-sync.)
if [[ -z "${RESULTSTORE_PARENT_BUILD_ID+x}" ]]
then
  # This is a top-level invocation.
  if [[ -n "${FX_BUILD_UUID+x}" ]]
  then
    # This is a top-level ninja invocation from 'fx build'.
    # Use FX_BUILD_UUID as the ninja invocation id.
    readonly RESULTSTORE_invocation_id="$FX_BUILD_UUID"
  else
    # This is a top-level ninja invocation from infra,
    # or some other invocation from outside of 'fx'.
    # Don't use BUILDBUCKET_ID.
    readonly RESULTSTORE_invocation_id="$(new_uuid)"
  fi
else
  # This is a sub-build invocation.
  readonly RESULTSTORE_invocation_id="$(new_uuid)"
fi

# Set additional build metadata based on environment variables
# set by parent invocations.
metadata=()
[[ -n "${FX_BUILD_UUID+x}" ]] && {
  metadata+=( FX_BUILD_UUID="$FX_BUILD_UUID" )
}
[[ -n "${BUILDBUCKET_ID+x}" ]] && {
  metadata+=( BUILDBUCKET_ID="$BUILDBUCKET_ID" )
}

# The following fields are passed from parent-to-child invocation.
# If not set (expected for top-level invocations), just ignore.
# See ninja_env below.
[[ -n "${RESULTSTORE_PARENT_BUILD_ID+x}" ]] && {
  metadata+=( PARENT_BUILD_ID="$RESULTSTORE_PARENT_BUILD_ID" )
}
if [[ -z "${RESULTSTORE_PARENT_BUILD_LINK+x}" ]]
then
  if [[ -n "${BUILDBUCKET_ID+x}" ]] then
    # Link this top-level build invocation to buildbucket.
    case "$BUILDBUCKET_ID" in
      */led/*)
        metadata+=( PARENT_BUILD_LINK="http://go/lucibuild/$BUILDBUCKET_ID/+/build.proto" ) ;;
      *)
        metadata+=( PARENT_BUILD_LINK="http://go/bbid/$BUILDBUCKET_ID" ) ;;
    esac
  fi
else
  metadata+=( PARENT_BUILD_LINK="$RESULTSTORE_PARENT_BUILD_LINK" )
fi
[[ -n "${RESULTSTORE_SIBLING_BUILDS_LINK+x}" ]] && {
  metadata+=( SIBLING_BUILDS_LINK="$RESULTSTORE_SIBLING_BUILDS_LINK" )
}

readonly CFG="$SCRIPT_DIR/fuchsia-resultstore.cfg"
readonly RESULTSTORE_URL="$(grep "^results_url=" "$CFG" | cut -d= -f2)"

# If there are no sub-builds, this query will just return empty.
readonly SUB_BUILDS_LINK="$RESULTSTORE_URL/?q=PARENT_BUILD_ID:$RESULTSTORE_invocation_id"
metadata+=( SUB_BUILDS_LINK="$SUB_BUILDS_LINK" )

ninja_metadata_args=()
for md in "${metadata[@]}"
do ninja_metadata_args+=( --bes_metadata "$md" )
done

readonly ninja_env=(
  # For this ninja invocation only:
  NINJA_BUILD_ID="$RESULTSTORE_invocation_id"

  # Replace the following environment variables with new values.
  # These variables are not seen by build tools like ninja and bazel directly,
  # but are used by their wrapper counterparts, like wrapper.bazel.sh.
  # Sub-builds of this invocation will see this invocation as the parent.
  RESULTSTORE_PARENT_BUILD_ID="$RESULTSTORE_invocation_id"
  RESULTSTORE_PARENT_BUILD_LINK="$RESULTSTORE_URL/$RESULTSTORE_invocation_id"
  # To sub-builds: "Your siblings are..."
  RESULTSTORE_SIBLING_BUILDS_LINK="$SUB_BUILDS_LINK"
)
# LINT.ThenChange(
#   //build/bazel/wrapper.bazel.sh:related_invocations_env_vars,
#   //build/bazel/scripts/rsninja.sh:related_invocations_env_vars
# )

readonly full_cmd=(
  env "${ninja_env[@]}"
  "$wrapper"
  "$ninja_bin"
  "${ninja_metadata_args[@]}"
  "$@"
)
exec "${full_cmd[@]}"