1 files changed, 109 insertions, 0 deletions
diff --git a/llvm_tools/llvm_local_bisection.sh b/llvm_tools/llvm_local_bisection.sh
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+++ b/llvm_tools/llvm_local_bisection.sh
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+#!/bin/bash -u
+# -*- coding: utf-8 -*-
+# Copyright 2022 The ChromiumOS Authors
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# llvm_bisection_template.sh
+#
+# This script is meant to be run inside a `git bisect` process, like so:
+#
+#   $ cd <your llvm-project dir>
+#   $ git bisect start
+#   $ git bisect bad <your bad ref>
+#   $ git bisect good <your good ref>
+#   $ git bisect run ~/chromimuos/src/scripts/llvm_bisection_template.sh
+#
+# This template exists as a "batteries included" LLVM bisection script,
+# which will modify the LLVM_NEXT hash to help the mage track down issues
+# locally.
+#
+# Modify the fixme sections below to customize to your bisection use-case.
+
+# FIXME: Replace this for the location of your llvm clone within the chroot.
+# We need this for the git history.
+LLVM_CLONE_PATH="${HOME}/chromiumos/src/third_party/llvm-project"
+
+main () {
+  # Note this builds with USE="llvm-next debug -thinlto -llvm_pgo_use continue-on-patch-failure"
+  build_llvm || exit
+
+  # FIXME: Write your actual bisection command here which uses
+  # LLVM_NEXT here.
+  #
+  # Example bisection command:
+  #
+  #   build_pkg efitools || exit 1
+  #
+  # You can use build_pkg if you want to emerge a package and print
+  # out diagnostics along the way
+  #
+  #   Fail Example: build_pkg "${MY_PACKAGE}" || exit 1
+  #   Skip Example: build_pkg "${MY_PACKAGE}" || exit 125
+  #
+}
+
+# ---------------------------------------------------------------------
+
+# Current LLVM_NEXT_HASH we're using. Does not need to be set.
+CURRENT='UNKNOWN'
+
+logdo () {
+  local cmd="${1}"
+  shift
+  printf '%1 $ %2' "$(date '+%T')" "${cmd}"
+  for i in "$@"; do
+    printf "'%1'" "${i}"
+  done
+  printf "\n"
+  "${cmd}" "$@"
+}
+
+log () {
+  echo "$(date '+%T') | $*"
+}
+
+build_llvm () {
+  cd "${LLVM_CLONE_PATH}" || exit 2  # Exit with error
+  local llvm_ebuild_path
+  llvm_ebuild_path="$(readlink -f "$(equery which llvm)")"
+  CURRENT="$(git rev-parse --short HEAD)"
+  log "Current hash=${CURRENT}"
+  NEW_LINE="LLVM_NEXT_HASH=\"${CURRENT}\""
+  sed -i "s/^LLVM_NEXT_HASH=\".*\"/${NEW_LINE}/" "${llvm_ebuild_path}"
+
+  local logfile="/tmp/build-llvm.${CURRENT}.out"
+  log "Writing logs to ${logfile}"
+  log "sudo USE='llvm-next debug -thinlto -llvm_use_pgo continue-on-patch-failure'" \
+      " emerge sys-devel/llvm"
+  logdo sudo USE='llvm-next debug -thinlto -llvm_use_pgo continue-on-patch-failure' emerge \
+    sys-devel/llvm \
+    &> "${logfile}"
+  local emerge_exit_code="$?"
+  if [[ "${emerge_exit_code}" -ne 0 ]]; then
+    log "FAILED to build llvm with hash=${CURRENT}"
+    log 'Skipping this hash'
+    return 125  # 125 is the "skip" exit code.
+  fi
+  log "Succesfully built LLVM with hash=${CURRENT}"
+  return 0  # Explicitly returning 0 for "good" even if a command errors out
+}
+
+build_pkg () {
+  local pkg="${1}"
+
+  local logfile="/tmp/build-${pkg}.${CURRENT}.out"
+  log "Writing logs to ${logfile}"
+  log "sudo emerge ${pkg}"
+  logdo sudo emerge "${pkg}" \
+    &> "${logfile}"
+  local emerge_exit_code="$?"
+  if [[ "${emerge_exit_code}" -ne 0 ]]; then
+    log "FAILED to build ${pkg} with hash=${CURRENT}"
+    return 1  # 1 here isn't for bisection, but for chaining with `||`
+  fi
+  log "Successfully built ${pkg} with hash=${CURRENT}"
+  return 0  # Explicitly returning 0 for "good" even if a command errors out
+}
+
+main