src: port --bash-completion to C++

So that it gets handle earlier and faster during the bootstrap
process.

Drive-by fixes:

- Remove `[has_eval_string]` and `[ssl_openssl_cert_store]` from
  the completion output
- Set `kProfProcess` execution mode for `--prof-process` instead
  of `kPrintBashProcess` which is removed in this patch.
- Append new line to the end of the output of --bash-completion

Author: joyeecheung

lib/internal/main/print_bash_completion.js

@@ -138,7 +138,6 @@
       'lib/internal/main/eval_string.js',
       'lib/internal/main/eval_stdin.js',
       'lib/internal/main/inspect.js',
-      'lib/internal/main/print_bash_completion.js',
       'lib/internal/main/print_help.js',
       'lib/internal/main/prof_process.js',
       'lib/internal/main/repl.js',

node.gyp

@@ -396,9 +396,6 @@ MaybeLocal<Value> StartMainThreadExecution(Environment* env) {
     return StartExecution(env, "internal/main/print_help");
   }
 
-  if (per_process::cli_options->print_bash_completion) {
-    return StartExecution(env, "internal/main/print_bash_completion");
-  }
 
   if (env->options()->prof_process) {
     return StartExecution(env, "internal/main/prof_process");
@@ -771,6 +768,12 @@ void Init(int* argc,
     exit(0);
   }
 
+  if (per_process::cli_options->print_bash_completion) {
+    std::string completion = options_parser::GetBashCompletion();
+    printf("%s\n", completion.c_str());
+    exit(0);
+  }
+
   if (per_process::cli_options->print_v8_help) {
     V8::SetFlagsFromString("--help", 6);  // Doesn't return.
     UNREACHABLE();
@@ -829,6 +832,12 @@ InitializationResult InitializeOncePerProcess(int argc, char** argv) {
     return result;
   }
 
+  if (per_process::cli_options->print_bash_completion) {
+    std::string completion = options_parser::GetBashCompletion();
+    printf("%s\n", completion.c_str());
+    exit(0);
+  }
+
   if (per_process::cli_options->print_v8_help) {
     V8::SetFlagsFromString("--help", 6);  // Doesn't return.
     UNREACHABLE();

src/node.cc

@@ -4,6 +4,8 @@
 #include "env-inl.h"
 #include "node_binding.h"
 
+#include <errno.h>
+#include <sstream>
 #include <cstdlib>  // strtoul, errno
 
 using v8::Boolean;
@@ -678,6 +680,43 @@ HostPort SplitHostPort(const std::string& arg,
                     ParseAndValidatePort(arg.substr(colon + 1), errors) };
 }
 
+std::string GetBashCompletion() {
+  Mutex::ScopedLock lock(per_process::cli_options_mutex);
+  const auto& parser = _ppop_instance;
+
+  std::ostringstream out;
+
+  out << "_node_complete() {\n"
+         "  local cur_word options\n"
+         "  cur_word=\"${COMP_WORDS[COMP_CWORD]}\"\n"
+         "  if [[ \"${cur_word}\" == -* ]] ; then\n"
+         "    COMPREPLY=( $(compgen -W '";
+
+  for (const auto& item : parser.options_) {
+    if (item.first[0] != '[') {
+      out << item.first << " ";
+    }
+  }
+  for (const auto& item : parser.aliases_) {
+    if (item.first[0] != '[') {
+      out << item.first << " ";
+    }
+  }
+  if (parser.aliases_.size() > 0) {
+    out.seekp(-1, out.cur);  // Strip the trailing space
+  }
+
+  out << "' -- \"${cur_word}\") )\n"
+         "    return 0\n"
+         "  else\n"
+         "    COMPREPLY=( $(compgen -f \"${cur_word}\") )\n"
+         "    return 0\n"
+         "  fi\n"
+         "}\n"
+         "complete -F _node_complete node node_g";
+  return out.str();
+}
+
 // Return a map containing all the options and their metadata as well
 // as the aliases
 void GetOptions(const FunctionCallbackInfo<Value>& args) {

src/node_options.cc

@@ -224,6 +224,7 @@ namespace options_parser {
 HostPort SplitHostPort(const std::string& arg,
     std::vector<std::string>* errors);
 void GetOptions(const v8::FunctionCallbackInfo<v8::Value>& args);
+std::string GetBashCompletion();
 
 enum OptionEnvvarSettings {
   kAllowedInEnvironment,
@@ -412,6 +413,7 @@ class OptionsParser {
   friend class OptionsParser;
 
   friend void GetOptions(const v8::FunctionCallbackInfo<v8::Value>& args);
+  friend std::string GetBashCompletion();
 };
 
 using StringVector = std::vector<std::string>;