src: use a std::vector for preload_modules

A dynamically allocated array was being used, simplify the memory
management by using std::vector.

PR-URL: https://github.com/nodejs/node/pull/12241
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Daniel Bevenius <daniel.bevenius@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>

src/node.cc

@@ -162,8 +162,7 @@ static bool throw_deprecation = false;
 static bool trace_sync_io = false;
 static bool track_heap_objects = false;
 static const char* eval_string = nullptr;
-static unsigned int preload_module_count = 0;
-static const char** preload_modules = nullptr;
+static std::vector<std::string> preload_modules;
 static const int v8_default_thread_pool_size = 4;
 static int v8_thread_pool_size = v8_default_thread_pool_size;
 static bool prof_process = false;
@@ -3277,21 +3276,18 @@ void SetupProcessObject(Environment* env,
     READONLY_PROPERTY(process, "_forceRepl", True(env->isolate()));
   }
 
-  if (preload_module_count) {
-    CHECK(preload_modules);
+  if (!preload_modules.empty()) {
     Local<Array> array = Array::New(env->isolate());
-    for (unsigned int i = 0; i < preload_module_count; ++i) {
+    for (unsigned int i = 0; i < preload_modules.size(); ++i) {
       Local<String> module = String::NewFromUtf8(env->isolate(),
-                                                 preload_modules[i]);
+                                                 preload_modules[i].c_str());
       array->Set(i, module);
     }
     READONLY_PROPERTY(process,
                       "_preload_modules",
                       array);
 
-    delete[] preload_modules;
-    preload_modules = nullptr;
-    preload_module_count = 0;
+    preload_modules.clear();
   }
 
   // --no-deprecation
@@ -3649,7 +3645,6 @@ static void ParseArgs(int* argc,
   const char** new_exec_argv = new const char*[nargs];
   const char** new_v8_argv = new const char*[nargs];
   const char** new_argv = new const char*[nargs];
-  const char** local_preload_modules = new const char*[nargs];
   bool use_bundled_ca = false;
   bool use_openssl_ca = false;
 
@@ -3657,7 +3652,6 @@ static void ParseArgs(int* argc,
     new_exec_argv[i] = nullptr;
     new_v8_argv[i] = nullptr;
     new_argv[i] = nullptr;
-    local_preload_modules[i] = nullptr;
   }
 
   // exec_argv starts with the first option, the other two start with argv[0].
@@ -3715,7 +3709,7 @@ static void ParseArgs(int* argc,
         exit(9);
       }
       args_consumed += 1;
-      local_preload_modules[preload_module_count++] = module;
+      preload_modules.push_back(module);
     } else if (strcmp(arg, "--check") == 0 || strcmp(arg, "-c") == 0) {
       syntax_check_only = true;
     } else if (strcmp(arg, "--interactive") == 0 || strcmp(arg, "-i") == 0) {
@@ -3835,16 +3829,6 @@ static void ParseArgs(int* argc,
   memcpy(argv, new_argv, new_argc * sizeof(*argv));
   delete[] new_argv;
   *argc = static_cast<int>(new_argc);
-
-  // Copy the preload_modules from the local array to an appropriately sized
-  // global array.
-  if (preload_module_count > 0) {
-    CHECK(!preload_modules);
-    preload_modules = new const char*[preload_module_count];
-    memcpy(preload_modules, local_preload_modules,
-           preload_module_count * sizeof(*preload_modules));
-  }
-  delete[] local_preload_modules;
 }