1SKIP_UNRELEASED_VERSIONS = false
 2# ...
 3
 4source 'https://rubygems.org'
 5gemspec
 6gem 'json', :git => 'https://github.com/segiddins/json.git', :branch => 'seg-1.7.7-ruby-2.2'
 7
 8group :development do
 9  cp_gem 'claide',                'CLAide'
10  cp_gem 'cocoapods-core',        'Core', '1-9-stable'
11  cp_gem 'cocoapods-deintegrate', 'cocoapods-deintegrate'
12  cp_gem 'cocoapods-downloader',  'cocoapods-downloader'
13  cp_gem 'cocoapods-plugins',     'cocoapods-plugins'
14  cp_gem 'cocoapods-search',      'cocoapods-search'
15  cp_gem 'cocoapods-stats',       'cocoapods-stats'
16  cp_gem 'cocoapods-trunk',       'cocoapods-trunk'
17  cp_gem 'cocoapods-try',         'cocoapods-try'
18  cp_gem 'molinillo',             'Molinillo'
19  cp_gem 'nanaimo',               'Nanaimo'
20  cp_gem 'xcodeproj',             'Xcodeproj'
21   
22  gem 'cocoapods-dependencies', '~> 1.0.beta.1'
23  # ...
24  # Integration tests
25  gem 'diffy'
26  gem 'clintegracon'
27  # Code Quality
28  gem 'inch_by_inch'
29  gem 'rubocop'
30  gem 'danger'
31end
32
33group :debugging do
34  gem 'cocoapods_debug'
35
36  gem 'rb-fsevent'
37  gem 'kicker'
38  gem 'awesome_print'
39  gem 'ruby-prof', :platforms => [:ruby]
40end

 1def cp_gem(name, repo_name, branch = 'master', path: false)
 2  return gem name if SKIP_UNRELEASED_VERSIONS
 3  opts = if path
 4           { :path => "../#{repo_name}" }
 5         else
 6           url = "https://github.com/CocoaPods/#{repo_name}.git"
 7           { :git => url, :branch => branch }
 8         end
 9  gem name, opts
10end

1$ ls -l
2lrwxr-xr-x  1 gua  staff    31 Jul 30 21:34 CocoaPods
3lrwxr-xr-x  1 gua  staff    26 Jul 31 13:27 Core 
4lrwxr-xr-x  1 gua  staff    31 Jul 31 10:14 Molinillo 
5lrwxr-xr-x  1 gua  staff    31 Aug 15 11:32 Xcodeproj 
6lrwxr-xr-x  1 gua  staff    42 Jul 31 10:14 cocoapods-downloader

1$ which pod
2/Users/edmond/.rvm/gems/ruby-2.6.1/bin/pod

1$ cat /Users/edmond/.rvm/gems/ruby-2.6.1/bin/pod

 1#!/usr/bin/env ruby_executable_hooks
 2
 3require 'rubygems'
 4version = ">= 0.a"
 5
 6str = ARGV.first
 7if str
 8  str = str.b[/\A_(.*)_\z/, 1]
 9  if str and Gem::Version.correct?(str)
10    version = str
11    ARGV.shift
12  end
13end
14
15if Gem.respond_to?(:activate_bin_path)
16    load Gem.activate_bin_path('cocoapods', 'pod', version)
17else
18    gem "cocoapods", version
19    load Gem.bin_path("cocoapods", "pod", version)
20end

 1#!/usr/bin/env ruby
 2# ... 忽略一些对于编码处理的代码
 3
 4require 'cocoapods'
 5
 6# 这里手动输出一下调用栈，来关注一下
 7puts caller
 8
 9# 如果环境配置中指定了 ruby-prof 配置文件，会对执行命令过程进行性能监控
10if profile_filename = ENV['COCOAPODS_PROFILE']
11  require 'ruby-prof'
12  # 依据配置文件类型加载不同的 reporter 解析器
13  # ...
14  File.open(profile_filename, 'w') do |io|
15    reporter.new(RubyProf.profile { Pod::Command.run(ARGV) }).print(io)
16  end
17else
18  Pod::Command.run(ARGV)
19end

1$ pod
2/Users/edmond/.rvm/gems/ruby-2.6.1/bin/pod:24:in `load'
3/Users/edmond/.rvm/gems/ruby-2.6.1/bin/pod:24:in `<main>'
4/Users/edmond/.rvm/gems/ruby-2.6.1/bin/ruby_executable_hooks:24:in `eval'
5/Users/edmond/.rvm/gems/ruby-2.6.1/bin/ruby_executable_hooks:24:in `<main>'

 1module Pod
 2  class Command
 3    class Install < Command
 4      # ... 
 5      def run
 6        # 判断是否存在 Podfile 文件，如果存在则进行 Podfile 的初始化
 7        verify_podfile_exists!
 8        # 从 Config 中获取一个 Instraller 实例
 9        installer = installer_for_config
10        # 默认是不执行 update
11        installer.repo_update = repo_update?(:default => false)
12        installer.update = false
13        installer.deployment = @deployment
14        # install 的真正过程
15        installer.install!
16      end
17    end
18  end
19end

 1def install!
 2    prepare
 3    resolve_dependencies
 4    download_dependencies
 5    validate_targets
 6    if installation_options.skip_pods_project_generation?
 7        show_skip_pods_project_generation_message
 8    else
 9        integrate
10    end
11    write_lockfiles
12    perform_post_install_actions
13end
14
15def integrate
16    generate_pods_project
17    if installation_options.integrate_targets?
18        integrate_user_project
19    else
20        UI.section 'Skipping User Project Integration'
21    end
22end

 1def prepare
 2  # 如果检测出当前目录是 Pods，直接 raise 终止
 3  if Dir.pwd.start_with?(sandbox.root.to_path)
 4    message = 'Command should be run from a directory outside Pods directory.'
 5    message << "\n\n\tCurrent directory is #{UI.path(Pathname.pwd)}\n"
 6    raise Informative, message
 7  end
 8  UI.message 'Preparing' do
 9    # 如果 lock 文件的 CocoaPods 主版本和当前版本不同，将以新版本的配置对 xcodeproj 工程文件进行更新
10    deintegrate_if_different_major_version
11    # 对 sandbox(Pods) 目录建立子目录结构
12    sandbox.prepare
13    # 检测 PluginManager 是否有 pre-install 的 plugin
14    ensure_plugins_are_installed!
15    # 执行插件中 pre-install 的所有 hooks 方法
16    run_plugins_pre_install_hooks
17  end
18end

 1def resolve_dependencies
 2    # 获取 Sources
 3    plugin_sources = run_source_provider_hooks
 4    # 创建一个 Analyzer
 5    analyzer = create_analyzer(plugin_sources)
 6
 7    # 如果带有 repo_update **标记**
 8    UI.section 'Updating local specs repositories' do
 9        # 执行 Analyzer 的更新 Repo 操作
10        analyzer.update_repositories
11    end if repo_update?
12
13    UI.section 'Analyzing dependencies' do
14        # 从 analyzer 取出最新的分析结果，@analysis_result，@aggregate_targets，@pod_targets
15        analyze(analyzer)
16        # 拼写错误降级识别，白名单过滤
17        validate_build_configurations
18    end
19
20    # 如果 deployment? 为 true，会验证 podfile & lockfile 是否需要更新
21    UI.section 'Verifying no changes' do
22        verify_no_podfile_changes!
23        verify_no_lockfile_changes!
24    end if deployment?
25 
26    analyzer
27end

 1def download_dependencies
 2  UI.section 'Downloading dependencies' do
 3    # 初始化 sandbox 文件访问器
 4    create_file_accessors
 5    # 构造 Pod Source Installer
 6    install_pod_sources
 7    # 执行 podfile 定义的 pre install 的 hooks
 8    run_podfile_pre_install_hooks
 9    # 根据配置清理 pod sources 信息，主要是清理无用 platform 相关内容
10    clean_pod_sources
11  end
12end

 1def install_pod_sources
 2 @installed_specs = []
 3 # install 的 Pod 只需要这两种状态，added 和 changed 状态的并集
 4 pods_to_install = sandbox_state.added | sandbox_state.changed
 5 title_options = { :verbose_prefix => '-> '.green }
 6 puts "root_specs"
 7 root_specs.each do |item|
 8   puts item
 9 end
10 # 将 Podfile 解析后排序处理
11 root_specs.sort_by(&:name).each do |spec|
12   # 如果是 added 或 changed 状态的 Pod
13   if pods_to_install.include?(spec.name)
14     # 如果是 changed 状态并且 manifest 已经有记录
15     if sandbox_state.changed.include?(spec.name) && sandbox.manifest
16       # 版本更新
17       current_version = spec.version
18       # 被更新版本记录
19       previous_version = sandbox.manifest.version(spec.name)
20       # 变动记录
21       has_changed_version = current_version != previous_version
22       # 找到第一个包含 spec.name 的 Pod，获取对应的 Repo，其实就是 find 方法
23       current_repo = analysis_result.specs_by_source.detect { |key, values| break key if values.map(&:name).include?(spec.name) }
24       # 获取当前仓库
25       current_repo &&= current_repo.url || current_repo.name
26       # 获取之前该仓库的信息
27       previous_spec_repo = sandbox.manifest.spec_repo(spec.name)
28       # 是否仓库有变动
29       has_changed_repo = !previous_spec_repo.nil? && current_repo && (current_repo != previous_spec_repo)
30
31       # 通过 title 输出上面的详细变更信息
32       title = ...
33     else
34       # 非 changed 状态，展示 Installing 这个是经常见的 log
35       title = "Installing #{spec}"
36     end
37     UI.titled_section(title.green, title_options) do
38       # 通过 name 拿到对应的 installer，记录到 @pod_installers 中
39       install_source_of_pod(spec.name)
40     end
41   else
42     # 如果没有 changed 情况，直接展示 Using，也是经常见到的 log
43     UI.titled_section("Using #{spec}", title_options) do
44       # # 通过 sandbox, specs 的 platform 信息生成 Installer 实例，记录到 @pod_installers 中
45       create_pod_installer(spec.name)
46     end
47   end
48 end
49end
50
51# 通过缓存返回 PodSourceInstaller 实例
52def create_pod_installer(pod_name)
53    specs_by_platform = specs_for_pod(pod_name)
54 
55    # 当通过 pod_name 无法找到对应的 pod_target 或 platform 配置，主动抛出错误信息
56    if specs_by_platform.empty?
57        requiring_targets = pod_targets.select { |pt| pt.recursive_dependent_targets.any? { |dt| dt.pod_name == pod_name } }
58        # message = "..."
59        raise StandardError, message
60    end
61    # 通过 sandbox, specs 的 platform 信息生成 Installer 实例
62    pod_installer = PodSourceInstaller.new(sandbox, podfile, specs_by_platform, :can_cache => installation_options.clean?)
63    pod_installers << pod_installer
64    pod_installer
65end
66
67# 如果 resolver 声明一个 Pod 已经安装或者已经存在，将会将其删除并重新安装。如果不存在则直接安装。
68def install_source_of_pod(pod_name)
69  pod_installer = create_pod_installer(pod_name)
70  pod_installer.install!
71  @installed_specs.concat(pod_installer.specs_by_platform.values.flatten.uniq)
72end

1def root_specs
2  analysis_result.specifications.map(&:root).uniq
3end

1def install!
2    download_source unless predownloaded? || local?
3    PodSourcePreparer.new(root_spec, root).prepare! if local?
4    sandbox.remove_local_podspec(name) unless predownloaded? || local? || external?
5end

 1def validate_targets
 2    validator = Xcode::TargetValidator.new(aggregate_targets, pod_targets, installation_options)
 3    validator.validate!
 4end
 5
 6def validate!
 7    verify_no_duplicate_framework_and_library_names
 8    verify_no_static_framework_transitive_dependencies
 9    verify_swift_pods_swift_version
10    verify_swift_pods_have_module_dependencies
11    verify_no_multiple_project_names if installation_options.generate_multiple_pod_projects?
12end

 1def integrate
 2    generate_pods_project
 3    if installation_options.integrate_targets?
 4        # 集成用户配置，读取依赖项，使用 xcconfig 来配置
 5        integrate_user_project
 6    else
 7        UI.section 'Skipping User Project Integration'
 8    end
 9end
10
11def generate_pods_project
12    # 创建 stage sanbox 用于保存安装前的沙盒状态，以支持增量编译的对比
13    stage_sandbox(sandbox, pod_targets)
14    # 检查是否支持增量编译，如果支持将返回 cache result
15    cache_analysis_result = analyze_project_cache
16    # 需要重新生成的 target
17    pod_targets_to_generate = cache_analysis_result.pod_targets_to_generate
18    # 需要重新生成的 aggregate target
19    aggregate_targets_to_generate = cache_analysis_result.aggregate_targets_to_generate
20
21    # 清理需要重新生成 target 的 header 和 pod folders
22    clean_sandbox(pod_targets_to_generate)
23    # 生成 Pod Project，组装 sandbox 中所有 Pod 的 path、build setting、源文件引用、静态库文件、资源文件等
24    create_and_save_projects(pod_targets_to_generate, aggregate_targets_to_generate,
25                                cache_analysis_result.build_configurations, cache_analysis_result.project_object_version)
26
27    # SandboxDirCleaner 用于清理增量 pod 安装中的无用 headers、target support files 目录
28    SandboxDirCleaner.new(sandbox, pod_targets, aggregate_targets).clean!
29    # 更新安装后的 cache 结果到目录 `Pods/.project_cache` 下
30    update_project_cache(cache_analysis_result, target_installation_results)
31end

 1def perform_post_install_actions
 2    # 调用 HooksManager 执行每个插件的 post_install 方法 
 3    run_plugins_post_install_hooks
 4    # 打印过期 pod target 警告
 5    warn_for_deprecations
 6    # 如果 pod 配置了 script phases 脚本，会主动输出一条提示消息
 7    warn_for_installed_script_phases
 8    # 输出结束信息 `Pod installation complete!`
 9    print_post_install_message
10end