From 3eb7918f8e387ef3c714c94de41275487d1f9c8f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tobias=20Nie=C3=9Fen?= <tniessen@tnie.de>
Date: Thu, 25 Aug 2022 02:28:46 +0200
Subject: [PATCH] src: make minor improvements to EnabledDebugList

Change the underlying type of DebugCategory to unsigned int so that it
can be safely cast to an unsigned type without having to worry about
negative values, removing the need for the DCHECK_GE statements.

To fully benefit from type safety, remove DebugCategory::CATEGORY_COUNT
and instead add a constexpr kDebugCategoryCount.

Remove the second argument from EnabledDebugList::set_enabled() and
EnabledDebugList::Parse() because it was always set to true.

PR-URL: https://github.com/nodejs/node/pull/44350
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Darshan Sen <raisinten@gmail.com>
---
 src/debug_utils.cc |  6 +++---
 src/debug_utils.h  | 27 +++++++++++++--------------
 2 files changed, 16 insertions(+), 17 deletions(-)

diff --git a/src/debug_utils.cc b/src/debug_utils.cc
index f721a672f10e67..69ef383ed22ca8 100644
--- a/src/debug_utils.cc
+++ b/src/debug_utils.cc
@@ -63,10 +63,10 @@ void EnabledDebugList::Parse(std::shared_ptr<KVStore> env_vars,
                              v8::Isolate* isolate) {
   std::string cats;
   credentials::SafeGetenv("NODE_DEBUG_NATIVE", &cats, env_vars, isolate);
-  Parse(cats, true);
+  Parse(cats);
 }
 
-void EnabledDebugList::Parse(const std::string& cats, bool enabled) {
+void EnabledDebugList::Parse(const std::string& cats) {
   std::string debug_categories = cats;
   while (!debug_categories.empty()) {
     std::string::size_type comma_pos = debug_categories.find(',');
@@ -76,7 +76,7 @@ void EnabledDebugList::Parse(const std::string& cats, bool enabled) {
   {                                                                            \
     static const std::string available_category = ToLower(#name);              \
     if (available_category.find(wanted) != std::string::npos)                  \
-      set_enabled(DebugCategory::name, enabled);                               \
+      set_enabled(DebugCategory::name);                                        \
   }
 
     DEBUG_CATEGORY_NAMES(V)
diff --git a/src/debug_utils.h b/src/debug_utils.h
index 19847e46549263..e2e702f586e20f 100644
--- a/src/debug_utils.h
+++ b/src/debug_utils.h
@@ -51,20 +51,21 @@ void NODE_EXTERN_PRIVATE FWrite(FILE* file, const std::string& str);
   V(WASI)                                                                      \
   V(MKSNAPSHOT)
 
-enum class DebugCategory {
+enum class DebugCategory : unsigned int {
 #define V(name) name,
   DEBUG_CATEGORY_NAMES(V)
 #undef V
-      CATEGORY_COUNT
 };
 
+#define V(name) +1
+constexpr unsigned int kDebugCategoryCount = DEBUG_CATEGORY_NAMES(V);
+#undef V
+
 class NODE_EXTERN_PRIVATE EnabledDebugList {
  public:
-  bool enabled(DebugCategory category) const {
-    DCHECK_GE(static_cast<int>(category), 0);
-    DCHECK_LT(static_cast<int>(category),
-              static_cast<int>(DebugCategory::CATEGORY_COUNT));
-    return enabled_[static_cast<int>(category)];
+  bool FORCE_INLINE enabled(DebugCategory category) const {
+    DCHECK_LT(static_cast<unsigned int>(category), kDebugCategoryCount);
+    return enabled_[static_cast<unsigned int>(category)];
   }
 
   // Uses NODE_DEBUG_NATIVE to initialize the categories. The env_vars variable
@@ -74,16 +75,14 @@ class NODE_EXTERN_PRIVATE EnabledDebugList {
              v8::Isolate* isolate = nullptr);
 
  private:
-  // Set all categories matching cats to the value of enabled.
-  void Parse(const std::string& cats, bool enabled);
-  void set_enabled(DebugCategory category, bool enabled) {
-    DCHECK_GE(static_cast<int>(category), 0);
-    DCHECK_LT(static_cast<int>(category),
-              static_cast<int>(DebugCategory::CATEGORY_COUNT));
+  // Enable all categories matching cats.
+  void Parse(const std::string& cats);
+  void set_enabled(DebugCategory category) {
+    DCHECK_LT(static_cast<unsigned int>(category), kDebugCategoryCount);
     enabled_[static_cast<int>(category)] = true;
   }
 
-  bool enabled_[static_cast<int>(DebugCategory::CATEGORY_COUNT)] = {false};
+  bool enabled_[kDebugCategoryCount] = {false};
 };
 
 template <typename... Args>