src/test/shell/bazel/bazel_thinlto_test.sh

#!/bin/bash
#
# Copyright 2019 The Bazel Authors. All rights reserved.
#
# 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 -eu

# Load the test setup defined in the parent directory
CURRENT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
source "${CURRENT_DIR}/../integration_test_setup.sh" \
  || { echo "integration_test_setup.sh not found!" >&2; exit 1; }

function write_hello_world_files {
  mkdir -p hello || fail "mkdir hello failed"
  cat >hello/BUILD <<EOF
cc_binary(
  name = 'hello',
  srcs = ['hello.cc'],
  deps = [":hello_lib"],
)

cc_library(
  name = "hello_lib",
  srcs = ["hellolib.cc"],
  hdrs = ["hello.h"],
)

EOF
  cat >hello/hello.h <<EOF
int hello1(void);
void hello2(void);
EOF

  cat >hello/hellolib.cc <<EOF
#include <iostream>
#include "hello.h"
using namespace std;

int hello1() {
  return 42;
}

void hello2() {
  cout << "Hi" << endl;
}
EOF

  cat >hello/hello.cc <<EOF
#include <iostream>
#include "hello.h"
int main() {
  hello2();
}
EOF
}

function test_bazel_thinlto() {

  if is_darwin; then
    echo "This test doesn't run on Darwin. Skipping."
    return
  fi

  local -r clang_tool=$(which clang)
  if [[ ! -x ${clang_tool:-/usr/bin/clang_tool} ]]; then
    echo "clang not installed. Skipping test."
    return
  fi

  local major_version=$($clang_tool --version | \
    grep -oP 'version.*' | cut -d' ' -f 2 | cut -d '.' -f 1)

  if [[ $major_version < 6 ]]; then
    echo "clang version is smaller than 6.0. Skipping test."
    return
  fi

  write_hello_world_files

  CC=$clang_tool bazel run \
    //hello:hello -c opt -s --features=thin_lto &>$TEST_log \
    || fail "Build with ThinLTO failed"

  grep -q "action 'LTO Backend Compile" $TEST_log \
    || fail "LTO Actions missing"

  if [[ ! -e bazel-bin/hello/hello.lto/hello/_objs/hello/hello.o.thinlto.bc ]] \
    || [[ ! -e bazel-bin/hello/hello.lto/hello/_objs/hello_lib/hellolib.o.thinlto.bc ]]; then
    fail "bitcode files were not generated"
  fi
}

run_suite "test ThinLTO"