shared method that exits early if everything is generated

include/flatbuffers/code_generators.h

@@ -29,6 +29,18 @@ class BaseGenerator {
  protected:
   virtual ~BaseGenerator(){};
 
+  bool IsEverythingGenerated() {
+    for (auto it = parser_.enums_.vec.begin(); it != parser_.enums_.vec.end();
+         ++it) {
+      if (!(*it)->generated) return false;
+    }
+    for (auto it = parser_.structs_.vec.begin();
+         it != parser_.structs_.vec.end(); ++it) {
+      if (!(*it)->generated) return false;
+    }
+    return true;
+  }
+
   const Parser &parser_;
   const std::string &path_;
   const std::string &file_name_;

src/idl_gen_cpp.cpp

@@ -724,21 +724,7 @@ class CppGenerator : public BaseGenerator {
   // structs,
   // and tables) and output them to a single file.
   bool generate() {
-    // Check if we have any code to generate at all, to avoid an empty header.
-    for (auto it = parser_.enums_.vec.begin(); it != parser_.enums_.vec.end();
-         ++it) {
-      if (!(*it)->generated) goto generate_code;
-    }
-    for (auto it = parser_.structs_.vec.begin(); it != parser_.structs_.vec.end();
-         ++it) {
-      if (!(*it)->generated) goto generate_code;
-    }
-    // No code to generate, exit:
-    return true;
-
-  generate_code:
-
-    using namespace cpp;
+    if (IsEverythingGenerated()) return true;
 
     std::string code;
     code =

src/idl_gen_js.cpp

@@ -678,31 +678,29 @@ class JsGenerator : public BaseGenerator {
   // Iterate through all definitions we haven't generate code for (enums,
   // structs, and tables) and output them to a single file.
   bool generate() {
+    if (IsEverythingGenerated()) return true;
+
     std::string enum_code, struct_code, exports_code, code;
     generateEnums(&enum_code, &exports_code);
     generateStructs(&struct_code, &exports_code);
 
-    // Only output file-level code if there were any declarations.
-    if (enum_code.length() || struct_code.length()) {
-      code +=
-          "// automatically generated by the FlatBuffers compiler, do not "
-          "modify\n\n";
+    code +=
+        "// automatically generated by the FlatBuffers compiler, do not "
+        "modify\n\n";
 
-      // Generate code for all the namespace declarations.
-      GenNamespaces(parser_, &code, &exports_code);
+    // Generate code for all the namespace declarations.
+    GenNamespaces(parser_, &code, &exports_code);
 
-      // Output the main declaration code from above.
-      code += enum_code;
-      code += struct_code;
+    // Output the main declaration code from above.
+    code += enum_code;
+    code += struct_code;
 
-      if (!exports_code.empty() && !parser_.opts.skip_js_exports) {
-        code += "// Exports for Node.js and RequireJS\n";
-        code += exports_code;
-      }
+    if (!exports_code.empty() && !parser_.opts.skip_js_exports) {
+      code += "// Exports for Node.js and RequireJS\n";
+      code += exports_code;
     }
 
-    return !code.length() ||
-           SaveFile(GeneratedFileName(path_, file_name_).c_str(), code, false);
+    return SaveFile(GeneratedFileName(path_, file_name_).c_str(), code, false);
   }
 
  private: