[lldb][NFCI] Refactor regex filtering logic in CommandObjectTypeFormatterList

[jgorbe]

Summary

Extract a bit of copy/pasted regex filtering logic into a separate function and simplify it a little bit.

[labath]

lldb/source/Commands/CommandObjectType.cpp

1064

What's up with all the parentheses? This is just a regular || between three choices...

[jgorbe]

Removed unnecessary parentheses.

[jgorbe]

lldb/source/Commands/CommandObjectType.cpp

1064

Thanks for catching it. Fixed.

lldb/source/Commands/CommandObjectType.cpp

public:
 
   ~CommandObjectTypeFormatterList() override = default;
 
 protected:
   virtual bool FormatterSpecificList(CommandReturnObject &result) {
     return false;
   }
 
+  static bool ShouldListItem(llvm::StringRef s, RegularExpression *regex) {
+    // If we have a regex, it can match two kinds of results:
+    //   - An item created with that same regex string (exact string match), so
+    //     the user can list it using the same string it used at creation time.
+    //   - Items that match the regex.
+    // No regex means list everything.
+    return regex == nullptr || s == regex->GetText() || regex->Execute(s);
+  }
+
   bool DoExecute(Args &command, CommandReturnObject &result) override {
     const size_t argc = command.GetArgumentCount();
 
     std::unique_ptr<RegularExpression> category_regex;
     std::unique_ptr<RegularExpression> formatter_regex;
 
     if (m_options.m_category_regex.OptionWasSet()) {
       category_regex = std::make_unique<RegularExpression>(
auto category_closure =
           "-----------------------\nCategory: %s%s\n-----------------------\n",
           category->GetName(), category->IsEnabled() ? "" : " (disabled)");
 
       TypeCategoryImpl::ForEachCallbacks<FormatterType> foreach;
       foreach
         .SetExact([&result, &formatter_regex, &any_printed](
                       const TypeMatcher &type_matcher,
                       const FormatterSharedPointer &format_sp) -> bool {
-          if (formatter_regex) {
-            bool escape = true;
-            if (type_matcher.CreatedBySameMatchString(
-                    ConstString(formatter_regex->GetText()))) {
-              escape = false;
-            } else if (formatter_regex->Execute(
-                           type_matcher.GetMatchString().GetStringRef())) {
-              escape = false;
-            }
-
-            if (escape)
-              return true;
-          }
-
+          if (ShouldListItem(type_matcher.GetMatchString().GetStringRef(),
+                             formatter_regex.get())) {
             any_printed = true;
             result.GetOutputStream().Printf(
                 "%s: %s\n", type_matcher.GetMatchString().GetCString(),
                 format_sp->GetDescription().c_str());
+          }
           return true;
         });
 
       foreach
         .SetWithRegex([&result, &formatter_regex, &any_printed](
                           const TypeMatcher &type_matcher,
                           const FormatterSharedPointer &format_sp) -> bool {
-          if (formatter_regex) {
-            bool escape = true;
-            if (type_matcher.CreatedBySameMatchString(
-                    ConstString(formatter_regex->GetText()))) {
-              escape = false;
-            } else if (formatter_regex->Execute(
-                           type_matcher.GetMatchString().GetStringRef())) {
-              escape = false;
-            }
-
-            if (escape)
-              return true;
-          }
-
+          if (ShouldListItem(type_matcher.GetMatchString().GetStringRef(),
+                             formatter_regex.get())) {
             any_printed = true;
             result.GetOutputStream().Printf(
                 "%s: %s\n", type_matcher.GetMatchString().GetCString(),
                 format_sp->GetDescription().c_str());
+          }
           return true;
         });
 
       category->ForEach(foreach);
     };
 
     if (m_options.m_category_language.OptionWasSet()) {
       lldb::TypeCategoryImplSP category_sp;
       DataVisualization::Categories::GetCategory(
           m_options.m_category_language.GetCurrentValue(), category_sp);
       if (category_sp)
         category_closure(category_sp);
     } else {
       DataVisualization::Categories::ForEach(
           [&category_regex, &category_closure](
               const lldb::TypeCategoryImplSP &category) -> bool {
-            if (category_regex) {
-              bool escape = true;
-              if (category->GetName() == category_regex->GetText()) {
-                escape = false;
-              } else if (category_regex->Execute(category->GetName())) {
-                escape = false;
-              }
-
-              if (escape)
-                return true;
-            }
-
+            if (ShouldListItem(category->GetName(), category_regex.get())) {
               category_closure(category);
-
+            }
             return true;
           });
 
       any_printed = FormatterSpecificList(result) | any_printed;
     }
 
     if (any_printed)
       result.SetStatus(eReturnStatusSuccessFinishResult);