#!/usr/bin/env bash
#===----------------------------------------------------------------------===##
#
# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
# See https://llvm.org/LICENSE.txt for license information.
# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#
#===----------------------------------------------------------------------===##

#
# This file generates a Buildkite pipeline that triggers the various CI jobs for
# the LLVM project during pre-commit CI.
#
# See https://buildkite.com/docs/agent/v3/cli-pipeline#pipeline-format.
#
# As this outputs a yaml file, it's possible to log messages to stderr or
# prefix with "#".


set -eu
set -o pipefail

# Environment variables script works with:

# Set by buildkite
: ${BUILDKITE_PULL_REQUEST_BASE_BRANCH:=}
: ${BUILDKITE_COMMIT:=}
: ${BUILDKITE_BRANCH:=}
# Fetch origin to have an up to date merge base for the diff.
git fetch origin
# List of files affected by this commit
: ${MODIFIED_FILES:=$(git diff --name-only origin/${BUILDKITE_PULL_REQUEST_BASE_BRANCH}...HEAD)}
# Filter rules for generic windows tests
: ${WINDOWS_AGENTS:='{"queue": "windows"}'}
# Filter rules for generic linux tests
: ${LINUX_AGENTS:='{"queue": "linux"}'}

reviewID="$(git log --format=%B -n 1 | sed -nE 's/^Review-ID:[[:space:]]*(.+)$/\1/p')"
if [[ "${reviewID}" != "" ]]; then
  buildMessage="https://llvm.org/${reviewID}"
else
  buildMessage="Push to branch ${BUILDKITE_BRANCH}"
fi

cat <<EOF
steps:
EOF

echo "Files modified:" >&2
echo "$MODIFIED_FILES" >&2
modified_dirs=$(echo "$MODIFIED_FILES" | cut -d'/' -f1 | sort -u)
echo "Directories modified:" >&2
echo "$modified_dirs" >&2

function compute-projects-to-test() {
  projects=${@}
  for project in ${projects}; do
    echo "${project}"
    case ${project} in
    lld)
      for p in bolt cross-project-tests; do
        echo $p
      done
    ;;
    llvm)
      for p in bolt clang clang-tools-extra flang lld lldb mlir polly; do
        echo $p
      done
    ;;
    clang)
      for p in clang-tools-extra compiler-rt lldb cross-project-tests; do
        echo $p
      done
    ;;
    clang-tools-extra)
      echo libc
    ;;
    mlir)
      echo flang
    ;;
    *)
      # Nothing to do
    ;;
    esac
  done
}

function add-dependencies() {
  projects=${@}
  for project in ${projects}; do
    echo "${project}"
    case ${project} in
    bolt)
      for p in clang lld llvm; do
        echo $p
      done
    ;;
    cross-project-tests)
      for p in lld clang; do
        echo $p
      done
    ;;
    clang-tools-extra)
      for p in llvm clang; do
        echo $p
      done
    ;;
    compiler-rt|libc|openmp)
      echo clang lld
    ;;
    flang|lldb|libclc)
      for p in llvm clang; do
        echo $p
      done
    ;;
    lld|mlir|polly)
      echo llvm
    ;;
    *)
      # Nothing to do
    ;;
    esac
  done
}

function exclude-linux() {
  projects=${@}
  for project in ${projects}; do
    case ${project} in
    cross-project-tests) ;; # tests failing
    lldb)                ;; # tests failing
    openmp)              ;; # https://github.com/google/llvm-premerge-checks/issues/410
    *)
      echo "${project}"
    ;;
    esac
  done
}

function exclude-windows() {
  projects=${@}
  for project in ${projects}; do
    case ${project} in
    cross-project-tests) ;; # tests failing
    compiler-rt)         ;; # tests taking too long
    openmp)              ;; # TODO: having trouble with the Perl installation
    libc)                ;; # no Windows support
    lldb)                ;; # tests failing
    bolt)                ;; # tests are not supported yet
    *)
      echo "${project}"
    ;;
    esac
  done
}

# Prints only projects that are both present in $modified_dirs and the passed
# list.
function keep-modified-projects() {
  projects=${@}
  for project in ${projects}; do
    if echo "$modified_dirs" | grep -q -E "^${project}$"; then
      echo "${project}"
    fi
  done
}

function check-targets() {
  projects=${@}
  for project in ${projects}; do
    case ${project} in
    clang-tools-extra)
      echo "check-clang-tools"
    ;;
    compiler-rt)
      echo "check-all"
    ;;
    cross-project-tests)
      echo "check-cross-project"
    ;;
    lldb)
      echo "check-all" # TODO: check-lldb may not include all the LLDB tests?
    ;;
    pstl)
      echo "check-all"
    ;;
    libclc)
      echo "check-all"
    ;;
    *)
      echo "check-${project}"
    ;;
    esac
  done
}

# Project specific pipelines.

# If libc++ or one of the runtimes directories changed.
if echo "$modified_dirs" | grep -q -E "^(libcxx|libcxxabi|libunwind|runtimes|cmake)$"; then
  cat <<EOF
- trigger: "libcxx-ci"
  build:
    message: "${buildMessage}"
    commit: "${BUILDKITE_COMMIT}"
    branch: "${BUILDKITE_BRANCH}"
EOF
fi

# If clang changed.
if echo "$modified_dirs" | grep -q -E "^(clang)$"; then
  cat <<EOF
- trigger: "clang-ci"
  build:
    message: "${buildMessage}"
    commit: "${BUILDKITE_COMMIT}"
    branch: "${BUILDKITE_BRANCH}"
EOF
fi

# Generic pipeline for projects that have not defined custom steps.
#
# Individual projects should instead define the pre-commit CI tests that suits their
# needs while letting them run on the infrastructure provided by LLVM.

# Figure out which projects need to be built on each platform
all_projects="bolt clang clang-tools-extra compiler-rt cross-project-tests flang libc libclc lld lldb llvm mlir openmp polly pstl"
modified_projects="$(keep-modified-projects ${all_projects})"

linux_projects_to_test=$(exclude-linux $(compute-projects-to-test ${modified_projects}))
linux_check_targets=$(check-targets ${linux_projects_to_test} | sort | uniq)
linux_projects=$(add-dependencies ${linux_projects_to_test} | sort | uniq)

windows_projects_to_test=$(exclude-windows $(compute-projects-to-test ${modified_projects}))
windows_check_targets=$(check-targets ${windows_projects_to_test} | sort | uniq)
windows_projects=$(add-dependencies ${windows_projects_to_test} | sort | uniq)

# Generate the appropriate pipeline
if [[ "${linux_projects}" != "" ]]; then
  cat <<EOF
- label: ':linux: Linux x64'
  artifact_paths:
  - 'artifacts/**/*'
  - '*_result.json'
  - 'build/test-results.xml'
  agents: ${LINUX_AGENTS}
  retry:
    automatic:
      - exit_status: -1  # Agent was lost
        limit: 2
      - exit_status: 255 # Forced agent shutdown
        limit: 2
  timeout_in_minutes: 120
  env:
    CC: 'clang'
    CXX: 'clang++'
  commands:
  - './.ci/monolithic-linux.sh "$(echo ${linux_projects} | tr ' ' ';')" "$(echo ${linux_check_targets})"'
EOF
fi

if [[ "${windows_projects}" != "" ]]; then
  cat <<EOF
- label: ':windows: Windows x64'
  artifact_paths:
  - 'artifacts/**/*'
  - '*_result.json'
  - 'build/test-results.xml'
  agents: ${WINDOWS_AGENTS}
  retry:
    automatic:
      - exit_status: -1  # Agent was lost
        limit: 2
      - exit_status: 255 # Forced agent shutdown
        limit: 2
  timeout_in_minutes: 150
  env:
    CC: 'cl'
    CXX: 'cl'
    LD: 'link'
  commands:
  - 'C:\\BuildTools\\Common7\\Tools\\VsDevCmd.bat -arch=amd64 -host_arch=amd64'
  - 'bash .ci/monolithic-windows.sh "$(echo ${windows_projects} | tr ' ' ';')" "$(echo ${windows_check_targets})"'
EOF
fi