Applied clang-tidy nullptr access warnings

src/common/clang_utils.cc

@@ -171,7 +171,7 @@ std::string to_string(const clang::Expr *expr)
     clang::LangOptions lang_options;
     std::string result;
     llvm::raw_string_ostream ostream(result);
-    expr->printPretty(ostream, NULL, clang::PrintingPolicy(lang_options));
+    expr->printPretty(ostream, nullptr, clang::PrintingPolicy(lang_options));
 
     return result;
 }
@@ -181,7 +181,7 @@ std::string to_string(const clang::Stmt *stmt)
     clang::LangOptions lang_options;
     std::string result;
     llvm::raw_string_ostream ostream(result);
-    stmt->printPretty(ostream, NULL, clang::PrintingPolicy(lang_options));
+    stmt->printPretty(ostream, nullptr, clang::PrintingPolicy(lang_options));
 
     return result;
 }
@@ -284,15 +284,15 @@ template <> id_t to_id(const std::filesystem::path &file)
 template <> id_t to_id(const clang::TemplateArgument &template_argument)
 {
     if (template_argument.getKind() == clang::TemplateArgument::Type) {
-        if (template_argument.getAsType()->getAs<clang::EnumType>() != nullptr)
-            return to_id(*template_argument.getAsType()
-                              ->getAs<clang::EnumType>()
-                              ->getAsTagDecl());
-        if (template_argument.getAsType()->getAs<clang::RecordType>() !=
-            nullptr)
-            return to_id(*template_argument.getAsType()
-                              ->getAs<clang::RecordType>()
-                              ->getAsRecordDecl());
+        if (const auto *enum_type =
+                template_argument.getAsType()->getAs<clang::EnumType>();
+            enum_type != nullptr)
+            return to_id(*enum_type->getAsTagDecl());
+
+        if (const auto *record_type =
+                template_argument.getAsType()->getAs<clang::RecordType>();
+            record_type != nullptr)
+            return to_id(*record_type->getAsRecordDecl());
     }
 
     throw std::runtime_error("Cannot generate id for template argument");

src/common/model/diagram.h

@@ -71,7 +71,7 @@ public:
     bool should_include(relationship_t r) const;
     bool should_include(access_t s) const;
 
-    virtual bool has_element(const diagram_element::id_t  /*id*/) const
+    virtual bool has_element(const diagram_element::id_t /*id*/) const
     {
         return false;
     }

src/common/visitor/comment/clang_visitor.cc

@@ -160,6 +160,9 @@ void clang_visitor::visit_param_command(
 
     std::string description;
 
+    if (command == nullptr)
+        return;
+
     const auto name = command->getParamNameAsWritten().str();
 
     for (const auto *it = command->child_begin(); it != command->child_end();
@@ -192,6 +195,9 @@ void clang_visitor::visit_tparam_command(
 
     std::string description;
 
+    if (command == nullptr)
+        return;
+
     const auto name = command->getParamNameAsWritten().str();
 
     for (const auto *it = command->child_begin(); it != command->child_end();
@@ -220,12 +226,16 @@ void clang_visitor::visit_paragraph(
     using clang::comments::Comment;
     using clang::comments::TextComment;
 
+    if (paragraph == nullptr)
+        return;
+
     for (const auto *text_it = paragraph->child_begin();
          text_it != paragraph->child_end(); ++text_it) {
 
-        if ((*text_it)->getCommentKind() == Comment::TextCommentKind) {
+        if ((*text_it)->getCommentKind() == Comment::TextCommentKind &&
+            clang::dyn_cast<TextComment>(*text_it) != nullptr) {
             // Merge paragraph lines into a single string
-            text += clang::dyn_cast<TextComment>((*text_it))->getText();
+            text += clang::dyn_cast<TextComment>(*text_it)->getText();
             text += "\n";
         }
     }