#!/usr/bin/env python
# utils/build-parser-lib - Helper tool for building the parser library -*- python -*-
#
# This source file is part of the Swift.org open source project
#
# Copyright (c) 2014 - 2019 Apple Inc. and the Swift project authors
# Licensed under Apache License v2.0 with Runtime Library Exception
#
# See https://swift.org/LICENSE.txt for license information
# See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors

# This is a utility for building only the syntax parser library as fast as possible
# by only building the necessary libraries for the parser library and nothing
# extraneous. To achieve this it does a single unified CMake configuration for
# llvm/clang/swift and builds only the parser library target.
# This mechanism is fundamentally different from build-script, which builds llvm/clang
# in a separate build directory than swift.
#
# Even though this bypasses build-script, it does share some underlying helper
# utilities from the python infrastructure.
#
# This utility also provides capability to gather profile data and build the parser
# library with PGO optimization enabled.

from __future__ import print_function

import multiprocessing
import os
import platform
import sys

from build_swift import argparse, defaults
from swift_build_support.swift_build_support import (
    shell,
)
from swift_build_support.swift_build_support.SwiftBuildSupport import (
    HOME,
    SWIFT_BUILD_ROOT,
    SWIFT_SOURCE_ROOT,
)
from swift_build_support.swift_build_support.toolchain import host_toolchain

isMac = platform.system() == 'Darwin'

def call_without_sleeping(command, env=None, dry_run=False, echo=False):
    """
    Execute a command during which system sleep is disabled.

    By default, this ignores the state of the `shell.dry_run` flag.
    """

    # Disable system sleep, if possible.
    if platform.system() == 'Darwin':
        # Don't mutate the caller's copy of the arguments.
        command = ["caffeinate"] + list(command)

    shell.call(command, env=env, dry_run=dry_run, echo=echo)

class Builder(object):
    def __init__(self, toolchain, args):
        self.toolchain = toolchain
        self.ninja_path = args.ninja_path
        self.build_release = args.release
        self.enable_assertions = not args.no_assertions
        self.lto_type = args.lto_type
        self.pgo_type = args.pgo_type
        self.profile_input = args.profile_input
        self.dry_run = args.dry_run
        self.jobs = args.build_jobs
        self.verbose = args.verbose
        self.build_dir = args.build_dir
        self.install_symroot = args.install_symroot
        self.install_destdir = args.install_destdir
        self.install_prefix = args.install_prefix
        self.version = args.version

    def call(self, command, env=None, without_sleeping=False):
        if without_sleeping:
            call_without_sleeping(command, env=env, dry_run=self.dry_run, echo=self.verbose)
        else:
            shell.call(command, env=env, dry_run=self.dry_run, echo=self.verbose)

    def configure(self, enable_debuginfo, instrumentation=None, profile_data=None):
        cmake_args = [self.toolchain.cmake, '-G', 'Ninja']
        cmake_args += ['-DCMAKE_MAKE_PROGRAM='+self.ninja_path]
        if isMac:
            cmake_args += ['-DCMAKE_OSX_DEPLOYMENT_TARGET=10.12', '-DSWIFT_DARWIN_DEPLOYMENT_VERSION_OSX=10.12']
        else:
            dispatch_source_path = os.path.join(SWIFT_SOURCE_ROOT, 'swift-corelibs-libdispatch')
            cmake_args += ['-DSWIFT_HOST_VARIANT=linux', '-DSWIFT_HOST_VARIANT_SDK=LINUX', '-DSWIFT_HOST_VARIANT_ARCH=x86_64',
                '-DSWIFT_PATH_TO_LIBDISPATCH_SOURCE:PATH='+dispatch_source_path,
                '-DLLVM_ENABLE_LLD=ON']
        cmake_args += ['-DLLVM_TARGETS_TO_BUILD=X86']
        if self.build_release:
            if enable_debuginfo:
                cmake_args += ['-DCMAKE_BUILD_TYPE:STRING=RelWithDebInfo']
            else:
                cmake_args += ['-DCMAKE_BUILD_TYPE:STRING=Release']
        else:
            cmake_args += ['-DCMAKE_BUILD_TYPE:STRING=Debug']
        if self.enable_assertions:
            cmake_args += ['-DLLVM_ENABLE_ASSERTIONS:BOOL=ON']
        if instrumentation:
            cmake_args += ['-DLLVM_BUILD_INSTRUMENTED='+instrumentation]
        if profile_data:
            cmake_args += ['-DLLVM_PROFDATA_FILE='+profile_data]
        if self.lto_type and not instrumentation:
            cmake_args += ['-DLLVM_ENABLE_LTO='+self.lto_type.upper()]
        if self.install_prefix:
            cmake_args += ['-DCMAKE_INSTALL_PREFIX:PATH='+self.install_prefix]
        if self.version:
            cmake_args += ['-DSWIFT_LIBPARSER_VER:STRING='+self.version]
        cmake_args += ['-DLLVM_ENABLE_PROJECTS=clang;swift', '-DLLVM_EXTERNAL_PROJECTS=swift']
        cmake_args += ['-DSWIFT_BUILD_ONLY_SYNTAXPARSERLIB=TRUE']
        cmake_args += ['-DSWIFT_BUILD_PERF_TESTSUITE=NO', '-DSWIFT_INCLUDE_DOCS=NO']
        cmake_args += ['-DSWIFT_BUILD_REMOTE_MIRROR=FALSE', '-DSWIFT_BUILD_DYNAMIC_STDLIB=FALSE',
            '-DSWIFT_BUILD_STATIC_STDLIB=FALSE', '-DSWIFT_BUILD_DYNAMIC_SDK_OVERLAY=FALSE',
            '-DSWIFT_BUILD_STATIC_SDK_OVERLAY=FALSE']
        # We are not using cmark but initialize the CMARK variables to something so that configure can succeed.
        cmake_args += ['-DCMARK_MAIN_INCLUDE_DIR='+os.path.join(SWIFT_SOURCE_ROOT, 'cmark'), '-DCMARK_BUILD_INCLUDE_DIR='+os.path.join(self.build_dir, 'cmark')]
        cmake_args += ['-DLLVM_INCLUDE_TESTS=FALSE', '-DCLANG_INCLUDE_TESTS=FALSE', '-DSWIFT_INCLUDE_TESTS=FALSE']
        cmake_args += [os.path.join(SWIFT_SOURCE_ROOT, 'llvm')]
        self.call(cmake_args)

    def build_target(self, build_dir, target, env=None):
        invocation = [self.toolchain.cmake, '--build', build_dir]
        invocation += ['--', '-j%d'%self.jobs]
        if self.verbose:
            invocation += ['-v']
        invocation += [target]
        self.call(invocation, env=env, without_sleeping=True)

    def install(self):
        print("--- Installing ---", file=sys.stderr)
        env = None
        if self.install_destdir:
            env = {'DESTDIR': self.install_destdir}
        self.build_target(self.build_dir, 'tools/swift/tools/libSwiftSyntaxParser/install', env=env)

    def extract_symbols(self):
        if not isMac:
            return
        extract_script = os.path.join(SWIFT_SOURCE_ROOT, "swift", "utils", "parser-lib", "darwin-extract-symbols")
        print("--- Extracting symbols ---", file=sys.stderr)
        env = {'INSTALL_DIR': self.install_destdir,
               'INSTALL_PREFIX': self.install_prefix,
               'INSTALL_SYMROOT': self.install_symroot,
               'BUILD_JOBS': str(self.jobs)}
        self.call([extract_script], env=env)

    def get_profile_data(self):
        profile_dir = os.path.join(self.build_dir, 'profiling')
        shell.makedirs(profile_dir, dry_run=self.dry_run)
        instrumentation = 'IR' if self.pgo_type == 'ir' else 'Frontend'
        with shell.pushd(profile_dir, dry_run=self.dry_run):
            self.configure(enable_debuginfo=False, instrumentation=instrumentation)
            self.build_target(profile_dir, 'swift-syntax-parser-test')
            # Delete existing profile data that were generated during building from running tablegen.
            shell.rmtree("profiles", dry_run=self.dry_run)
            self.call([os.path.join("bin", "swift-syntax-parser-test"), self.profile_input, '-time'])
            self.call([self.toolchain.llvm_profdata, "merge", "-output=profdata.prof", "profiles"])
        return os.path.join(profile_dir, "profdata.prof")

    def run(self):
        shell.makedirs(self.build_dir, dry_run=self.dry_run)

        profile_data = None
        if self.pgo_type:
            profile_data = self.get_profile_data()

        with shell.pushd(self.build_dir, dry_run=self.dry_run):
            self.configure(enable_debuginfo=True, profile_data=profile_data)

        self.build_target(self.build_dir, 'swift-syntax-parser-test')

        if self.install_destdir:
            self.install()
        if self.install_symroot:
            self.extract_symbols()


def main():
    parser = argparse.ArgumentParser(
        formatter_class=argparse.RawDescriptionHelpFormatter,
        description="""Builds Swift Syntax Parser library.""")
    optbuilder = parser.to_builder()
    option = optbuilder.add_option
    store = optbuilder.actions.store
    store_true = optbuilder.actions.store_true
    store_int = optbuilder.actions.store_int
    store_path = optbuilder.actions.store_path

    toolchain = host_toolchain(xcrun_toolchain='default')

    default_profile_input = os.path.join(SWIFT_SOURCE_ROOT, "swift", "utils", "parser-lib", "profile-input.swift")
    default_jobs = multiprocessing.cpu_count()
    default_build_dir = os.path.join(SWIFT_BUILD_ROOT, 'parser-lib')
    default_install_prefix = defaults.DARWIN_INSTALL_PREFIX if isMac else UNIX_INSTALL_PREFIX
    default_ninja = toolchain.ninja

    option('--release', store_true,
        help='build in release mode')
    option('--lto', store('lto_type'),
           choices=['thin', 'full'],
           const='full',
           metavar='LTO_TYPE',
           help='use lto optimization.'
                'Options: thin, full. If no optional arg is provided, full is '
                'chosen by default')
    option('--pgo', store('pgo_type'),
           choices=['frontend', 'ir'],
           const='ir',
           metavar='PGO_TYPE',
           help='use pgo optimization.'
                'Options: frontend, ir. If no optional arg is provided, ir is '
                'chosen by default')
    option('--profile-input', store_path,
           default=default_profile_input,
           help='the source file to use for PGO profiling input (default = %s)' % default_profile_input)
    option('--no-assertions', store_true,
        help='disable assertions')
    option(['-v', '--verbose'], store_true,
           help='print the commands executed during the build')
    option('--dry-run', store_true,
           help='print the commands to execute but not actually execute them')
    option(['-j', '--jobs'], store_int('build_jobs'),
           default=default_jobs,
           help='the number of parallel build jobs to use (default = %s)' % default_jobs)
    option('--build-dir', store_path,
           default=default_build_dir,
           help='the path where the build products will be placed. (default = %s)' % default_build_dir)
    option('--install-symroot', store_path,
           help='the path to install debug symbols into')
    option('--install-destdir', store_path,
           help='the path to use as the filesystem root for the installation')
    option('--install-prefix', store,
           default = default_install_prefix,
           help='the install prefix to use (default = %s)' % default_install_prefix)
    option('--version', store,
           help='version string to use for the parser library')
    option('--ninja-path', store_path,
           default = default_ninja,
           help='the path to ninja (default = %s)' % default_ninja)

    parser = optbuilder.build()
    args = parser.parse_args()

    builder = Builder(toolchain, args)
    builder.run()
    return 0

if __name__ == "__main__":
    try:
        sys.exit(main())
    except KeyboardInterrupt:
        sys.exit(1)