src: avoid strcmp() with Utf8Value

Having Utf8Value::operator==() without operator!=() is awkward in C++17,
so add the negated equality operator. Then, use either instead of
strcmp() where appropriate.

PR-URL: #47827
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Mohammed Keyvanzadeh <mohammadkeyvanzade94@gmail.com>
Reviewed-By: Darshan Sen <raisinten@gmail.com>
Reviewed-By: Filip Skokan <panva.ip@gmail.com>

src/crypto/crypto_context.cc

@@ -841,8 +841,7 @@ void SecureContext::SetECDHCurve(const FunctionCallbackInfo<Value>& args) {
 
   Utf8Value curve(env->isolate(), args[0]);
 
-  if (strcmp(*curve, "auto") != 0 &&
-      !SSL_CTX_set1_curves_list(sc->ctx_.get(), *curve)) {
+  if (curve != "auto" && !SSL_CTX_set1_curves_list(sc->ctx_.get(), *curve)) {
     return THROW_ERR_CRYPTO_OPERATION_FAILED(env, "Failed to set ECDH curve");
   }
 }

src/crypto/crypto_tls.cc

@@ -1350,8 +1350,7 @@ unsigned int TLSWrap::PskServerCallback(
 
   // Make sure there are no utf8 replacement symbols.
   Utf8Value identity_utf8(env->isolate(), identity_str);
-  if (strcmp(*identity_utf8, identity) != 0)
-    return 0;
+  if (identity_utf8 != identity) return 0;
 
   Local<Value> argv[] = {
     identity_str,

src/node_report.cc

@@ -401,7 +401,7 @@ static void PrintJavaScriptErrorProperties(JSONWriter* writer,
         continue;
       }
       node::Utf8Value k(isolate, key);
-      if (!strcmp(*k, "stack") || !strcmp(*k, "message")) continue;
+      if (k == "stack" || k == "message") continue;
       node::Utf8Value v(isolate, value_string);
       writer->json_keyvalue(k.ToStringView(), v.ToStringView());
     }

src/util.h

@@ -525,9 +525,8 @@ class Utf8Value : public MaybeStackBuffer<char> {
  public:
   explicit Utf8Value(v8::Isolate* isolate, v8::Local<v8::Value> value);
 
-  inline bool operator==(const char* a) const {
-    return strcmp(out(), a) == 0;
-  }
+  inline bool operator==(const char* a) const { return strcmp(out(), a) == 0; }
+  inline bool operator!=(const char* a) const { return !(*this == a); }
 };
 
 class TwoByteValue : public MaybeStackBuffer<uint16_t> {