[Symbol] Fix some botched logic in Variable::GetLanguage

[xiaobai]

Summary

I messed up the logic for this. Fixing with some improvements suggested
by Pavel.

[labath]

Thanks for responding quickly. LGTM, with one comment..

source/Symbol/Variable.cpp

62 ↗

(On Diff #211352)

if you want to keep the assignment in the if condition, then I think the best way to express that would be to say if((lang = func->GetLanguage()) != lldb::eLanguageTypeUnknown). That way one does not have to wonder "why is this code checking the zero value too and what does that mean?", and the check against eLanguageTypeUnknown is still explicit.

[jingham]

In D65165#1598553, @labath wrote:

Thanks for responding quickly. LGTM, with one comment..

Don't use checks that assume eLanguageTypeUnknown == 0, that seems really confusing and we don't use that practice anywhere else. Pavel's suggestion seems fine.

[JDevlieghere]

LGTM with Pavel's suggestion.

[xiaobai]

Implement suggestion

lldb/trunk/source/Symbol/Variable.cpp

 Variable::~Variable() {}
 
 lldb::LanguageType Variable::GetLanguage() const {
   lldb::LanguageType lang = m_mangled.GuessLanguage();
   if (lang != lldb::eLanguageTypeUnknown)
     return lang;
 
   if (auto *func = m_owner_scope->CalculateSymbolContextFunction()) {
-    if ((lang = func->GetLanguage()) && lang != lldb::eLanguageTypeUnknown)
+    if ((lang = func->GetLanguage()) != lldb::eLanguageTypeUnknown)
       return lang;
-    else if (auto *comp_unit =
-                 m_owner_scope->CalculateSymbolContextCompileUnit())
-      if ((lang = func->GetLanguage()) && lang != lldb::eLanguageTypeUnknown)
-        return lang;
+  } else if (auto *comp_unit =
+                 m_owner_scope->CalculateSymbolContextCompileUnit()) {
+    if ((lang = comp_unit->GetLanguage()) != lldb::eLanguageTypeUnknown)
   }
 
   return lldb::eLanguageTypeUnknown;
 }
 
 ConstString Variable::GetName() const {
   ConstString name = m_mangled.GetName(GetLanguage());
   if (name)