[clang:sema] de-duplicate getDepthAndIndex helpers

[nickdesaulniers]

Summary

Continuing off of:
https://reviews.llvm.org/D38382

Fixes:
https://bugs.llvm.org/show_bug.cgi?id=12176

[vsk]

Thanks for doing this!

include/clang/Sema/SemaInternal.h

120

Perhaps 'const auto *TTP = ...' would read better here, given that the expected type appears once already in the r.h.s of the expression? I have the same comment re: the three other casts above.

[nickdesaulniers]

• prefer auto when type is specified on RHS of assignment.

[nickdesaulniers]

Thanks for the review. Today is my first day committing to clang!

[vsk]

In D49760#1174141, @nickdesaulniers wrote:

Thanks for the review. Today is my first day committing to clang!

Welcome :).

LGTM. Feel free to commit this yourself once you obtain commit access (https://llvm.org/docs/DeveloperPolicy.html#obtaining-commit-access). I'd also be happy to commit this on your behalf.

include/clang/Sema/SemaInternal.h

assert(!(D->hasAttr<DLLImportAttr>() && D->hasAttr<DLLExportAttr>()) &&
          "A declaration cannot be both dllimport and dllexport.");
   if (auto *Import = D->getAttr<DLLImportAttr>())
     return Import;
   if (auto *Export = D->getAttr<DLLExportAttr>())
     return Export;
   return nullptr;
 }
 
+/// Retrieve the depth and index of a template parameter.
+inline std::pair<unsigned, unsigned> getDepthAndIndex(NamedDecl *ND) {
+  if (const auto *TTP = dyn_cast<TemplateTypeParmDecl>(ND))
+    return std::make_pair(TTP->getDepth(), TTP->getIndex());
+
+  if (const auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(ND))
+    return std::make_pair(NTTP->getDepth(), NTTP->getIndex());
+
+  const auto *TTP = cast<TemplateTemplateParmDecl>(ND);
+  return std::make_pair(TTP->getDepth(), TTP->getIndex());
+}
+
+/// Retrieve the depth and index of an unexpanded parameter pack.
+inline std::pair<unsigned, unsigned>
+getDepthAndIndex(UnexpandedParameterPack UPP) {
+  if (const auto *TTP = UPP.first.dyn_cast<const TemplateTypeParmType *>())
+    return std::make_pair(TTP->getDepth(), TTP->getIndex());
+
+  return getDepthAndIndex(UPP.first.get<NamedDecl *>());
+}
+
 class TypoCorrectionConsumer : public VisibleDeclConsumer {
   typedef SmallVector<TypoCorrection, 1> TypoResultList;
   typedef llvm::StringMap<TypoResultList> TypoResultsMap;
   typedef std::map<unsigned, TypoResultsMap> TypoEditDistanceMap;
 
 public:
   TypoCorrectionConsumer(Sema &SemaRef,
                          const DeclarationNameInfo &TypoName,

lib/Sema/SemaTemplateDeduction.cpp

case Type::DependentSizedArray:
     return IsPossiblyOpaquelyQualifiedType(
                                       cast<ArrayType>(T)->getElementType());
 
   default:
     return false;
   }
 }
 
-/// Retrieve the depth and index of a template parameter.
-static std::pair<unsigned, unsigned>
-getDepthAndIndex(NamedDecl *ND) {
-  if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ND))
-    return std::make_pair(TTP->getDepth(), TTP->getIndex());
-
-  if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(ND))
-    return std::make_pair(NTTP->getDepth(), NTTP->getIndex());
-
-  TemplateTemplateParmDecl *TTP = cast<TemplateTemplateParmDecl>(ND);
-  return std::make_pair(TTP->getDepth(), TTP->getIndex());
-}
-
-/// Retrieve the depth and index of an unexpanded parameter pack.
-static std::pair<unsigned, unsigned>
-getDepthAndIndex(UnexpandedParameterPack UPP) {
-  if (const TemplateTypeParmType *TTP
-                          = UPP.first.dyn_cast<const TemplateTypeParmType *>())
-    return std::make_pair(TTP->getDepth(), TTP->getIndex());
-
-  return getDepthAndIndex(UPP.first.get<NamedDecl *>());
-}
-
 /// Helper function to build a TemplateParameter when we don't
 /// know its type statically.
 static TemplateParameter makeTemplateParameter(Decl *D) {
   if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(D))
     return TemplateParameter(TTP);
   if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(D))
     return TemplateParameter(NTTP);
 

lib/Sema/SemaTemplateInstantiate.cpp

for (SmallVectorImpl<CodeSynthesisContext>::const_reverse_iterator
     // non-instantiation SFINAE context, then SFINAE applies.
     if (Active->SavedInNonInstantiationSFINAEContext)
       return Optional<TemplateDeductionInfo *>(nullptr);
   }
 
   return None;
 }
 
-/// Retrieve the depth and index of a parameter pack.
-static std::pair<unsigned, unsigned> 
-getDepthAndIndex(NamedDecl *ND) {
-  if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ND))
-    return std::make_pair(TTP->getDepth(), TTP->getIndex());
-  
-  if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(ND))
-    return std::make_pair(NTTP->getDepth(), NTTP->getIndex());
-  
-  TemplateTemplateParmDecl *TTP = cast<TemplateTemplateParmDecl>(ND);
-  return std::make_pair(TTP->getDepth(), TTP->getIndex());
-}
-
 //===----------------------------------------------------------------------===/
 // Template Instantiation for Types
 //===----------------------------------------------------------------------===/
 namespace {
   class TemplateInstantiator : public TreeTransform<TemplateInstantiator> {
     const MultiLevelTemplateArgumentList &TemplateArgs;
     SourceLocation Loc;
     DeclarationName Entity;

lib/Sema/SemaTemplateVariadic.cpp

 #include "clang/Sema/Template.h"
 
 using namespace clang;
 
 //----------------------------------------------------------------------------
 // Visitor that collects unexpanded parameter packs
 //----------------------------------------------------------------------------
 
-/// Retrieve the depth and index of a parameter pack.
-static std::pair<unsigned, unsigned> 
-getDepthAndIndex(NamedDecl *ND) {
-  if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ND))
-    return std::make_pair(TTP->getDepth(), TTP->getIndex());
-  
-  if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(ND))
-    return std::make_pair(NTTP->getDepth(), NTTP->getIndex());
-  
-  TemplateTemplateParmDecl *TTP = cast<TemplateTemplateParmDecl>(ND);
-  return std::make_pair(TTP->getDepth(), TTP->getIndex());
-}
-
 namespace {
   /// A class that collects unexpanded parameter packs.
   class CollectUnexpandedParameterPacksVisitor :
     public RecursiveASTVisitor<CollectUnexpandedParameterPacksVisitor> 
   {
     typedef RecursiveASTVisitor<CollectUnexpandedParameterPacksVisitor>
       inherited;