src: make CLI options programatically accesible

Provide `internalBinding('options')` with some utilities around making the options parser and current options values programatically accessible.
nodejs · addaleax · Aug 23, 2018 · Aug 23, 2018 · Aug 23, 2018 · Aug 27, 2018
commit 3ef59611318b29606da7c4d2d52df4379eaa6318
diff --git a/src/env.h b/src/env.h
@@ -118,6 +118,7 @@ struct PackageConfig {
 // for the sake of convenience.  Strings should be ASCII-only.
 #define PER_ISOLATE_STRING_PROPERTIES(V)                                      \
   V(address_string, "address")                                                \
+  V(aliases_string, "aliases")                                                \
   V(args_string, "args")                                                      \
   V(async, "async")                                                           \
   V(async_ids_stack_string, "async_ids_stack")                                \
@@ -156,6 +157,7 @@ struct PackageConfig {
   V(entries_string, "entries")                                                \
   V(entry_type_string, "entryType")                                           \
   V(env_pairs_string, "envPairs")                                             \
+  V(env_var_settings_string, "envVarSettings")                                \
   V(errno_string, "errno")                                                    \
   V(error_string, "error")                                                    \
   V(exit_code_string, "exitCode")                                             \
@@ -176,6 +178,7 @@ struct PackageConfig {
   V(get_shared_array_buffer_id_string, "_getSharedArrayBufferId")             \
   V(gid_string, "gid")                                                        \
   V(handle_string, "handle")                                                  \
+  V(help_text_string, "helpText")                                             \
   V(homedir_string, "homedir")                                                \
   V(host_string, "host")                                                      \
   V(hostmaster_string, "hostmaster")                                          \
@@ -233,6 +236,7 @@ struct PackageConfig {
   V(onunpipe_string, "onunpipe")                                              \
   V(onwrite_string, "onwrite")                                                \
   V(openssl_error_stack, "opensslErrorStack")                                 \
+  V(options_string, "options")                                                \
   V(output_string, "output")                                                  \
   V(order_string, "order")                                                    \
   V(parse_error_string, "Parse Error")                                        \

diff --git a/src/node.cc b/src/node.cc
@@ -126,6 +126,8 @@ typedef int mode_t;
 
 namespace node {
 
+using options_parser::kAllowedInEnvironment;
+using options_parser::kDisallowedInEnvironment;
 using v8::Array;
 using v8::ArrayBuffer;
 using v8::Boolean;
@@ -183,6 +185,7 @@ bool linux_at_secure = false;
 // process-relative uptime base, initialized at start-up
 double prog_start_time;
 
+Mutex per_process_opts_mutex;
 std::shared_ptr<PerProcessOptions> per_process_opts {
     new PerProcessOptions() };
 
@@ -2346,8 +2349,6 @@ void LoadEnvironment(Environment* env) {
 }
 
 static void PrintHelp() {
-  // XXX: If you add an option here, please also add it to doc/node.1 and
-  // doc/api/cli.md
   printf("Usage: node [options] [ -e script | script.js | - ] [arguments]\n"
          "       node inspect script.js [arguments]\n"
          "\n"
@@ -2747,13 +2748,20 @@ void ProcessArgv(std::vector<std::string>* args,
   // Parse a few arguments which are specific to Node.
   std::vector<std::string> v8_args;
   std::string error;
-  PerProcessOptionsParser::instance.Parse(
-      args,
-      exec_args,
-      &v8_args,
-      per_process_opts.get(),
-      is_env ? kAllowedInEnvironment : kDisallowedInEnvironment,
-      &error);
+
+  {
+    // TODO(addaleax): The mutex here should ideally be held during the
+    // entire function, but that doesn't play well with the exit() calls below.
+    Mutex::ScopedLock lock(per_process_opts_mutex);
+    options_parser::PerProcessOptionsParser::instance.Parse(
+        args,
+        exec_args,
+        &v8_args,
+        per_process_opts.get(),
+        is_env ? kAllowedInEnvironment : kDisallowedInEnvironment,
+        &error);
+  }
+
   if (!error.empty()) {
     fprintf(stderr, "%s: %s\n", args->at(0).c_str(), error.c_str());
     exit(9);

diff --git a/src/node_internals.h b/src/node_internals.h
@@ -119,6 +119,7 @@ struct sockaddr;
     V(js_stream)                                                              \
     V(messaging)                                                              \
     V(module_wrap)                                                            \
+    V(options)                                                                \
     V(os)                                                                     \
     V(performance)                                                            \
     V(pipe_wrap)                                                              \
@@ -176,6 +177,7 @@ extern Mutex environ_mutex;
 // Tells whether it is safe to call v8::Isolate::GetCurrent().
 extern bool v8_initialized;
 
+extern Mutex per_process_opts_mutex;
 extern std::shared_ptr<PerProcessOptions> per_process_opts;
 
 extern const char* const environment_flags[];

diff --git a/src/node_options-inl.h b/src/node_options-inl.h
@@ -21,73 +21,88 @@ EnvironmentOptions* PerIsolateOptions::get_per_env_options() {
   return per_env.get();
 }
 
+namespace options_parser {
+
 template <typename Options>
 void OptionsParser<Options>::AddOption(const std::string& name,
+                                       const std::string& help_text,
                                        bool Options::* field,
                                        OptionEnvvarSettings env_setting) {
-  options_.emplace(name, OptionInfo {
-    kBoolean,
-    std::make_shared<SimpleOptionField<bool>>(field),
-    env_setting
-  });
+  options_.emplace(name,
+                   OptionInfo{kBoolean,
+                              std::make_shared<SimpleOptionField<bool>>(field),
+                              env_setting,
+                              help_text});
 }
 
 template <typename Options>
 void OptionsParser<Options>::AddOption(const std::string& name,
+                                       const std::string& help_text,
                                        int64_t Options::* field,
                                        OptionEnvvarSettings env_setting) {
-  options_.emplace(name, OptionInfo {
-    kInteger,
-    std::make_shared<SimpleOptionField<int64_t>>(field),
-    env_setting
-  });
+  options_.emplace(
+      name,
+      OptionInfo{kInteger,
+                 std::make_shared<SimpleOptionField<int64_t>>(field),
+                 env_setting,
+                 help_text});
 }
 
 template <typename Options>
 void OptionsParser<Options>::AddOption(const std::string& name,
+                                       const std::string& help_text,
                                        std::string Options::* field,
                                        OptionEnvvarSettings env_setting) {
-  options_.emplace(name, OptionInfo {
-    kString,
-    std::make_shared<SimpleOptionField<std::string>>(field),
-    env_setting
-  });
+  options_.emplace(
+      name,
+      OptionInfo{kString,
+                 std::make_shared<SimpleOptionField<std::string>>(field),
+                 env_setting,
+                 help_text});
 }
 
 template <typename Options>
 void OptionsParser<Options>::AddOption(
     const std::string& name,
+    const std::string& help_text,
     std::vector<std::string> Options::* field,
     OptionEnvvarSettings env_setting) {
   options_.emplace(name, OptionInfo {
     kStringList,
     std::make_shared<SimpleOptionField<std::vector<std::string>>>(field),
-    env_setting
+    env_setting,
+    help_text
   });
 }
 
 template <typename Options>
 void OptionsParser<Options>::AddOption(const std::string& name,
+                                       const std::string& help_text,
                                        HostPort Options::* field,
                                        OptionEnvvarSettings env_setting) {
-  options_.emplace(name, OptionInfo {
-    kHostPort,
-    std::make_shared<SimpleOptionField<HostPort>>(field),
-    env_setting
-  });
+  options_.emplace(
+      name,
+      OptionInfo{kHostPort,
+                 std::make_shared<SimpleOptionField<HostPort>>(field),
+                 env_setting,
+                 help_text});
 }
 
 template <typename Options>
-void OptionsParser<Options>::AddOption(const std::string& name, NoOp no_op_tag,
+void OptionsParser<Options>::AddOption(const std::string& name,
+                                       const std::string& help_text,
+                                       NoOp no_op_tag,
                                        OptionEnvvarSettings env_setting) {
-  options_.emplace(name, OptionInfo { kNoOp, nullptr, env_setting });
+  options_.emplace(name, OptionInfo{kNoOp, nullptr, env_setting, help_text});
 }
 
 template <typename Options>
 void OptionsParser<Options>::AddOption(const std::string& name,
+                                       const std::string& help_text,
                                        V8Option v8_option_tag,
                                        OptionEnvvarSettings env_setting) {
-  options_.emplace(name, OptionInfo { kV8Option, nullptr, env_setting });
+  options_.emplace(name,
+                   OptionInfo{kV8Option, nullptr, env_setting, help_text});
 }
 
 template <typename Options>
@@ -161,11 +176,10 @@ template <typename ChildOptions>
 auto OptionsParser<Options>::Convert(
     typename OptionsParser<ChildOptions>::OptionInfo original,
     ChildOptions* (Options::* get_child)()) {
-  return OptionInfo {
-    original.type,
-    Convert(original.field, get_child),
-    original.env_setting
-  };
+  return OptionInfo{original.type,
+                    Convert(original.field, get_child),
+                    original.env_setting,
+                    original.help_text};
 }
 
 template <typename Options>
@@ -385,24 +399,21 @@ void OptionsParser<Options>::Parse(
 
     switch (info.type) {
       case kBoolean:
-        *std::static_pointer_cast<OptionField<bool>>(info.field)
-            ->Lookup(options) = true;
+        *Lookup<bool>(info.field, options) = true;
         break;
       case kInteger:
-        *std::static_pointer_cast<OptionField<int64_t>>(info.field)
-            ->Lookup(options) = std::atoll(value.c_str());
+        *Lookup<int64_t>(info.field, options) = std::atoll(value.c_str());
         break;
       case kString:
-        *std::static_pointer_cast<OptionField<std::string>>(info.field)
-            ->Lookup(options) = value;
+        *Lookup<std::string>(info.field, options) = value;
         break;
       case kStringList:
-        std::static_pointer_cast<OptionField<std::vector<std::string>>>(
-            info.field)->Lookup(options)->emplace_back(std::move(value));
+        Lookup<std::vector<std::string>>(info.field, options)
+            ->emplace_back(std::move(value));
         break;
       case kHostPort:
-        std::static_pointer_cast<OptionField<HostPort>>(info.field)
-            ->Lookup(options)->Update(SplitHostPort(value, error));
+        Lookup<HostPort>(info.field, options)
+            ->Update(SplitHostPort(value, error));
         break;
       case kNoOp:
         break;
@@ -415,6 +426,7 @@ void OptionsParser<Options>::Parse(
   }
 }
 
+}  // namespace options_parser
 }  // namespace node
 
 #endif  // defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS