[clang][ExtractAPI] Refactor ExtractAPIVisitor to make it more extens…

…ible

Use CRTP to enable creating statically dispatched subclasses of
ExtractAPIVisitor.
This enables adding extension points and customising the behavior more
easily.

This is used in CXExtractAPI.cpp to create a specialized visitor for
Libclang as well as streamlining the batch implementation in ExtractAPIConsumer.cpp

clang/lib/ExtractAPI/CMakeLists.txt

@@ -8,7 +8,6 @@ add_clang_library(clangExtractAPI
   APIIgnoresList.cpp
   AvailabilityInfo.cpp
   ExtractAPIConsumer.cpp
-  ExtractAPIVisitor.cpp
   DeclarationFragments.cpp
   Serialization/SerializerBase.cpp
   Serialization/SymbolGraphSerializer.cpp

clang/lib/ExtractAPI/DeclarationFragments.cpp

@@ -12,7 +12,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "clang/ExtractAPI/DeclarationFragments.h"
-#include "TypedefUnderlyingTypeResolver.h"
+#include "clang/ExtractAPI/TypedefUnderlyingTypeResolver.h"
 #include "clang/Index/USRGeneration.h"
 #include "llvm/ADT/StringSwitch.h"
 

clang/lib/ExtractAPI/ExtractAPIConsumer.cpp

@@ -12,8 +12,10 @@
 ///
 //===----------------------------------------------------------------------===//
 
+#include "clang/AST/ASTConcept.h"
 #include "clang/AST/ASTConsumer.h"
 #include "clang/AST/ASTContext.h"
+#include "clang/AST/DeclObjC.h"
 #include "clang/Basic/DiagnosticFrontend.h"
 #include "clang/Basic/SourceLocation.h"
 #include "clang/Basic/SourceManager.h"
@@ -33,6 +35,7 @@
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallVector.h"
+#include "llvm/Support/Casting.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/MemoryBuffer.h"
@@ -164,7 +167,7 @@ std::optional<std::string> getRelativeIncludeName(const CompilerInstance &CI,
 
 struct LocationFileChecker {
   bool operator()(SourceLocation Loc) {
-    // If the loc refers to a macro expansion we need to first get the file
+    // If the loc refersSourceLocationxpansion we need to first get the file
     // location of the expansion.
     auto &SM = CI.getSourceManager();
     auto FileLoc = SM.getFileLoc(Loc);
@@ -219,19 +222,42 @@ struct LocationFileChecker {
   llvm::DenseSet<const FileEntry *> ExternalFileEntries;
 };
 
+struct BatchExtractAPIVisitor : ExtractAPIVisitor<BatchExtractAPIVisitor> {
+  bool shouldDeclBeIncluded(const Decl *D) const {
+    bool ShouldBeIncluded = true;
+    // Check that we have the definition for redeclarable types.
+    if (auto *TD = llvm::dyn_cast<TagDecl>(D))
+      ShouldBeIncluded = TD->isThisDeclarationADefinition();
+    else if (auto *Interface = llvm::dyn_cast<ObjCInterfaceDecl>(D))
+      ShouldBeIncluded = Interface->isThisDeclarationADefinition();
+    else if (auto *Protocol = llvm::dyn_cast<ObjCProtocolDecl>(D))
+      ShouldBeIncluded = Protocol->isThisDeclarationADefinition();
+
+    ShouldBeIncluded = ShouldBeIncluded && LCF(D->getLocation());
+    return ShouldBeIncluded;
+  }
+
+  BatchExtractAPIVisitor(LocationFileChecker &LCF, ASTContext &Context,
+                         APISet &API)
+      : ExtractAPIVisitor<BatchExtractAPIVisitor>(Context, API), LCF(LCF) {}
+
+private:
+  LocationFileChecker &LCF;
+};
+
 class ExtractAPIConsumer : public ASTConsumer {
 public:
   ExtractAPIConsumer(ASTContext &Context,
                      std::unique_ptr<LocationFileChecker> LCF, APISet &API)
-      : Visitor(Context, *LCF, API), LCF(std::move(LCF)) {}
+      : Visitor(*LCF, Context, API), LCF(std::move(LCF)) {}
 
   void HandleTranslationUnit(ASTContext &Context) override {
     // Use ExtractAPIVisitor to traverse symbol declarations in the context.
     Visitor.TraverseDecl(Context.getTranslationUnitDecl());
   }
 
 private:
-  ExtractAPIVisitor Visitor;
+  BatchExtractAPIVisitor Visitor;
   std::unique_ptr<LocationFileChecker> LCF;
 };