[clang][Index] Enable indexing of Template Type Parameters behind a flag

Summary:
clangd uses indexing api to provide references and it was not possible
to perform symbol information for template parameters. This patch enables
visiting of TemplateTypeParmTypeLocs.

Reviewers: ilya-biryukov, akyrtzi

Subscribers: javed.absar, kristof.beyls, ioeric, arphaman, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D58293

llvm-svn: 354560

5 files changed, 19 insertions, 4 deletions

diff --git a/clang/lib/Index/IndexDecl.cpp b/clang/lib/Index/IndexDecl.cpp
index eb0b3d4a70e..0f6d6212a24 100644
--- a/clang/lib/Index/IndexDecl.cpp
+++ b/clang/lib/Index/IndexDecl.cpp
@@ -672,6 +672,8 @@ public:
         shouldIndexTemplateParameterDefaultValue(Parent)) {
       const TemplateParameterList *Params = D->getTemplateParameters();
       for (const NamedDecl *TP : *Params) {
+        if (IndexCtx.shouldIndexTemplateParameters())
+          IndexCtx.handleDecl(TP);
         if (const auto *TTP = dyn_cast<TemplateTypeParmDecl>(TP)) {
           if (TTP->hasDefaultArgument())
             IndexCtx.indexTypeSourceInfo(TTP->getDefaultArgumentInfo(), Parent);
diff --git a/clang/lib/Index/IndexSymbol.cpp b/clang/lib/Index/IndexSymbol.cpp
index 27e62af19f2..d21c673dee4 100644
--- a/clang/lib/Index/IndexSymbol.cpp
+++ b/clang/lib/Index/IndexSymbol.cpp
@@ -55,9 +55,6 @@ bool index::isFunctionLocalSymbol(const Decl *D) {
   if (isa<ParmVarDecl>(D))
     return true;
 
-  if (isa<TemplateTemplateParmDecl>(D))
-    return true;
-
   if (isa<ObjCTypeParamDecl>(D))
     return true;
 
diff --git a/clang/lib/Index/IndexTypeSourceInfo.cpp b/clang/lib/Index/IndexTypeSourceInfo.cpp
index e791a9d4a3c..9f9740b6079 100644
--- a/clang/lib/Index/IndexTypeSourceInfo.cpp
+++ b/clang/lib/Index/IndexTypeSourceInfo.cpp
@@ -45,6 +45,13 @@ public:
       return false;                                                            \
   } while (0)
 
+  bool VisitTemplateTypeParmTypeLoc(TemplateTypeParmTypeLoc TTPL) {
+    SourceLocation Loc = TTPL.getNameLoc();
+    TemplateTypeParmDecl *TTPD = TTPL.getDecl();
+    return IndexCtx.handleReference(TTPD, Loc, Parent, ParentDC,
+                                    SymbolRoleSet());
+  }
+
   bool VisitTypedefTypeLoc(TypedefTypeLoc TL) {
     SourceLocation Loc = TL.getNameLoc();
     TypedefNameDecl *ND = TL.getTypedefNameDecl();
diff --git a/clang/lib/Index/IndexingContext.cpp b/clang/lib/Index/IndexingContext.cpp
index 3d2d7d4ff02..d01dd50f3b5 100644
--- a/clang/lib/Index/IndexingContext.cpp
+++ b/clang/lib/Index/IndexingContext.cpp
@@ -44,6 +44,10 @@ bool IndexingContext::shouldIndexParametersInDeclarations() const {
   return IndexOpts.IndexParametersInDeclarations;
 }
 
+bool IndexingContext::shouldIndexTemplateParameters() const {
+  return IndexOpts.IndexTemplateParameters;
+}
+
 bool IndexingContext::handleDecl(const Decl *D,
                                  SymbolRoleSet Roles,
                                  ArrayRef<SymbolRelation> Relations) {
@@ -76,8 +80,11 @@ bool IndexingContext::handleReference(const NamedDecl *D, SourceLocation Loc,
   if (!shouldIndexFunctionLocalSymbols() && isFunctionLocalSymbol(D))
     return true;
 
-  if (isa<NonTypeTemplateParmDecl>(D) || isa<TemplateTypeParmDecl>(D))
+  if (!shouldIndexTemplateParameters() &&
+      (isa<NonTypeTemplateParmDecl>(D) || isa<TemplateTypeParmDecl>(D) ||
+       isa<TemplateTemplateParmDecl>(D))) {
     return true;
+  }
 
   return handleDeclOccurrence(D, Loc, /*IsRef=*/true, Parent, Roles, Relations,
                               RefE, RefD, DC);
diff --git a/clang/lib/Index/IndexingContext.h b/clang/lib/Index/IndexingContext.h
index 7765fa73f82..3136878c080 100644
--- a/clang/lib/Index/IndexingContext.h
+++ b/clang/lib/Index/IndexingContext.h
@@ -63,6 +63,8 @@ public:
 
   bool shouldIndexParametersInDeclarations() const;
 
+  bool shouldIndexTemplateParameters() const;
+
   static bool isTemplateImplicitInstantiation(const Decl *D);
 
   bool handleDecl(const Decl *D, SymbolRoleSet Roles = SymbolRoleSet(),