Comment AST: Find out if function is variadic in DeclInfo::fill

[aaronpuchert]

Summary

Then we don't have to look into the declaration again. Also it's only
natural to collect this information alongside parameters and return
type, as it's also just a parameter in some sense.

[gribozavr2]

Thank you for the cleanup!

clang/include/clang/AST/Comment.h

struct DeclInfo {
   /// Can be true only if \c IsFunctionDecl is true.
   unsigned IsInstanceMethod : 1;
 
   /// Is \c CommentDecl a static member function of C++ class or
   /// class method of ObjC class.
   /// Can be true only if \c IsFunctionDecl is true.
   unsigned IsClassMethod : 1;
 
+  /// Is \c CommentDecl something we consider a "function" that's variadic.
+  unsigned IsVariadic : 1;
+
   void fill();
 
   DeclKind getKind() const LLVM_READONLY {
     return static_cast<DeclKind>(Kind);
   }
 
   TemplateDeclKind getTemplateKind() const LLVM_READONLY {
     return static_cast<TemplateDeclKind>(TemplateKind);

clang/lib/AST/Comment.cpp

void DeclInfo::fill() {
   assert(!IsFilled);
 
   // Set defaults.
   Kind = OtherKind;
   TemplateKind = NotTemplate;
   IsObjCMethod = false;
   IsInstanceMethod = false;
   IsClassMethod = false;
+  IsVariadic = false;
   ParamVars = None;
   TemplateParameters = nullptr;
 
   if (!CommentDecl) {
     // If there is no declaration, the defaults is our only guess.
     IsFilled = true;
     return;
   }
case Decl::CXXConversion: {
     }
 
     if (K == Decl::CXXMethod || K == Decl::CXXConstructor ||
         K == Decl::CXXDestructor || K == Decl::CXXConversion) {
       const CXXMethodDecl *MD = cast<CXXMethodDecl>(CommentDecl);
       IsInstanceMethod = MD->isInstance();
       IsClassMethod = !IsInstanceMethod;
     }
+    IsVariadic = FD->isVariadic();
     break;
   }
   case Decl::ObjCMethod: {
     const ObjCMethodDecl *MD = cast<ObjCMethodDecl>(CommentDecl);
     Kind = FunctionKind;
     ParamVars = MD->parameters();
     ReturnType = MD->getReturnType();
     IsObjCMethod = true;
     IsInstanceMethod = MD->isInstanceMethod();
     IsClassMethod = !IsInstanceMethod;
+    IsVariadic = MD->isVariadic();
     break;
   }
   case Decl::FunctionTemplate: {
     const FunctionTemplateDecl *FTD = cast<FunctionTemplateDecl>(CommentDecl);
     Kind = FunctionKind;
     TemplateKind = Template;
     const FunctionDecl *FD = FTD->getTemplatedDecl();
     ParamVars = FD->parameters();
     ReturnType = FD->getReturnType();
     TemplateParameters = FTD->getTemplateParameters();
+    IsVariadic = FD->isVariadic();
     break;
   }
   case Decl::ClassTemplate: {
     const ClassTemplateDecl *CTD = cast<ClassTemplateDecl>(CommentDecl);
     Kind = ClassKind;
     TemplateKind = Template;
     TemplateParameters = CTD->getTemplateParameters();
     break;
void DeclInfo::fill() {
   // extract arguments and return type.
   if (TSI) {
     TypeLoc TL = TSI->getTypeLoc().getUnqualifiedLoc();
     FunctionTypeLoc FTL;
     if (getFunctionTypeLoc(TL, FTL)) {
       Kind = FunctionKind;
       ParamVars = FTL.getParams();
       ReturnType = FTL.getReturnLoc().getType();
+      if (const auto *FPT = dyn_cast<FunctionProtoType>(FTL.getTypePtr()))
+        IsVariadic = FPT->isVariadic();
     }
   }
 
   IsFilled = true;
 }
 
 StringRef ParamCommandComment::getParamName(const FullComment *FC) const {
   assert(isParamIndexValid());

clang/lib/AST/CommentSema.cpp

 }
 
 bool Sema::isAnyFunctionDecl() {
   return isFunctionDecl() && ThisDeclInfo->CurrentDecl &&
          isa<FunctionDecl>(ThisDeclInfo->CurrentDecl);
 }
 
 bool Sema::isFunctionOrMethodVariadic() {
-  if (!isFunctionDecl() || !ThisDeclInfo->CurrentDecl)
-    return false;
-  if (const FunctionDecl *FD =
-        dyn_cast<FunctionDecl>(ThisDeclInfo->CurrentDecl))
-    return FD->isVariadic();
-  if (const FunctionTemplateDecl *FTD =
-        dyn_cast<FunctionTemplateDecl>(ThisDeclInfo->CurrentDecl))
-    return FTD->getTemplatedDecl()->isVariadic();
-  if (const ObjCMethodDecl *MD =
-        dyn_cast<ObjCMethodDecl>(ThisDeclInfo->CurrentDecl))
-    return MD->isVariadic();
-  if (const TypedefNameDecl *TD =
-          dyn_cast<TypedefNameDecl>(ThisDeclInfo->CurrentDecl)) {
-    QualType Type = TD->getUnderlyingType();
-    if (Type->isFunctionPointerType() || Type->isBlockPointerType())
-      Type = Type->getPointeeType();
-    if (const auto *FT = Type->getAs<FunctionProtoType>())
-      return FT->isVariadic();
-  }
+  if (!ThisDeclInfo)
     return false;
+  if (!ThisDeclInfo->IsFilled)
+    inspectThisDecl();
+  return ThisDeclInfo->IsVariadic;
 }
 
 bool Sema::isObjCMethodDecl() {
   return isFunctionDecl() && ThisDeclInfo->CurrentDecl &&
          isa<ObjCMethodDecl>(ThisDeclInfo->CurrentDecl);
 }
 
 bool Sema::isFunctionPointerVarDecl() {

clang/test/Sema/warn-documentation.cpp

  * @param a
  * works
  *
  * @param ...
  * now should work too.
  */
 using VariadicFnType2 = void (*)(int a, ...);
 
+/*!
+ * Function pointer type variable.
+ *
+ * @param a
+ * works
+ *
+ * @param ...
+ * now should work too.
+ */
+void (*variadicFnVar)(int a, ...);
+
 // expected-warning@+2 {{empty paragraph passed to '@note' command}}
 /**
 @note
 \f$\texttt{mu}_{00}=\texttt{m}_{00}\f$, \f$\texttt{nu}_{00}=1\f$
 \f$\texttt{nu}_{10}=\texttt{mu}_{10}=\texttt{mu}_{01}=\texttt{mu}_{10}=0\f$
  */
 class EmptyNoteNoCrash {
 };