tools/devshell/contrib/ls-buildid

#!/bin/bash
# Copyright 2023 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.

#### CATEGORY=Build
### Find binaries among build directories, the checkout, and Google Cloud
### Storage (GCS) matching a given build ID.

## usage: fx ls-buildid [--help|-h] [--verbose|-v] [--local|-l] BUILD_ID
##
## Searches for all binaries having the given GNU build ID across all build
## directories, prebuilt .build-id directories, and (optionally) within
## Google Cloud Storage (GCS).
##
## Search includes GCS by default, but this can be overridden to be strictly
## local with `--local`. Remote search takes a dependency on `gcloud` being on
## one's $PATH, as well as users having authenticated with GCS via
## `gcloud auth login`.
##
## It is assumed that build directories are of all of the form
## $FUCHSIA_DIR/out/foo.
##
##  --verbose|-v   Be explicit in the build directories and GCS buckets being
##                 searched.
##
##  --local|-l     Limit the search to local files (i.e., excluding cloud
##                 storage).
##

source "$(cd "$(dirname "${BASH_SOURCE[0]}")" >/dev/null 2>&1 && pwd)"/../lib/vars.sh || exit $?
fx-config-read

# These are the standard buckets to which official Fuchsia infrastructure
# uploads binaries.
readonly GSUTIL_BUCKETS=(
  fuchsia-artifacts
  fuchsia-artifacts-internal
  fuchsia-artifacts-release
)

id=""
local=false
verbose=false
while [[ $# -ne 0 ]]; do
  case "$1" in
  --help|-h)
    fx-command-help
    exit 0
    ;;
  --remote|-r)
    fx-error "Remote search is now the default!"
    fx-command-help
    exit 0
    ;;
  --local|-l)
    local=true
    ;;
  --verbose|-v)
    verbose=true
    ;;
  -*)
    fx-error "Unknown flag: $1"
    fx-command-help
    exit 1
    ;;
  *)
    if [[ -z "${id}" ]]; then
      id="$1"
    else
      fx-error "Unexpected argument: '$1'"
      exit 1
    fi
    ;;
  esac
  shift
done

# With a remote search, let's make sure we can actually access GCS.
if ! $local ; then
  if ( ! type gcloud &>/dev/null ); then
    fx-warn "\`gcloud\` not on \$PATH. Proceeding with a strictly local search..."
    local=true
  elif ( ! gcloud auth print-access-token &>/dev/null ); then
    fx-warn "You've not yet run \`gcloud auth login\`! Proceeding with a strictly local search..."
    local=true
  fi
fi

# Relativize against the current working directory on a best-effort basis,
# because that makes for nicer output.
readonly out_dir="${FUCHSIA_OUT_DIR#"$(pwd)"/}"
prebuilt_dir="${FUCHSIA_DIR}/prebuilt"
readonly prebuilt_dir="${prebuilt_dir#"$(pwd)"/}"

# Aggregate all .build-id directories across the various build directories, as
# well as those shipped with prebuilts in the checkout.
build_id_dirs=("${out_dir}"/**/.build-id)
mapfile -t -O "${#build_id_dirs[@]}" build_id_dirs < <(find "${prebuilt_dir}" -type d -name .build-id)

if $verbose ; then
  fx-info "Searching the following .build-id directories:"
  printf "* %s\n" "${build_id_dirs[@]}"
fi

matches=()
for build_id_dir in "${build_id_dirs[@]}"; do
  # The would-be entry in the .build-id directory.
  dirent="${build_id_dir}/${id:0:2}/${id:2}"

  # Whether the .build-id directory is in a build or prebuilt directory, the
  # binaries it corresponds to should all lie within the parent.
  search_dir="$(dirname "${build_id_dir}")"
  if [[ -f "${dirent}" ]]; then
      mapfile -t -O "${#matches[@]}" matches < <(find "${search_dir}" -samefile "${dirent}")
  fi
done

# Build up a list of inaccessible buckets.
inaccessible_buckets=()
if ! $local ; then
  if $verbose ; then
    fx-info "Searching the following GCS buckets:"
    printf "* gs://%s\n" "${GSUTIL_BUCKETS[@]}"
  fi

  for bucket in "${GSUTIL_BUCKETS[@]}"; do
    # This gives the current GCS scheme for binaries indexed by build ID.
    url="gs://$bucket/debug/${id}.debug"

    # `gcloud storage` offers no convenient way to check whether the user has
    # access to a given GCS bucket. When we attempt to `ls` a file, and an error
    # is returned, it becomes difficult to disambiguate between a situation
    # where we have insufficient privileges to access to the storage, from one
    # where the file simply does not exist.  For now, if we have a non-zero
    # error code, we check the output for the string "matched no objects".  If
    # we see that, we just assume that the file does not exist.  Otherwise, we
    # assume something went wrong and report it to the user as a potential lack
    # of privilege.
    output=$(gcloud storage ls "${url}" 2>&1)
    result=$?
    if [[ $result != 0 && "${output}" != *"matched no objects"* ]]; then
      inaccessible_buckets+=("gs://${bucket}")
      continue
    fi
    if [[ $result == 0 ]]; then
      matches+=("${url}")
    fi
  done
fi

if [[ ${#matches[@]} -eq 0 ]] ; then
  fx-warn "No binaries found with build ID \"${id}\""

  # It's only worth printing this in the event of no matches.
  if [[ ${#inaccessible_buckets[@]} -ne 0 ]] ; then
    fx-warn "Something went wrong when attempting to access the following buckets:"
    printf "* %s\n" "${inaccessible_buckets[@]}"
    fx-warn "You may have insufficient privileges and might need to run 'gcloud auth login'"
  fi
else
  printf "%s\n" "${matches[@]}"
fi