CXXRecordDecl: Split getBases/getVBases into a slow and a fast path.

This avoids costly computation of getASTContext() and drops the header
dependency from DeclCXX.h to ASTContext.h.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@159716 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 18 insertions, 2 deletions

diff --git a/include/clang/AST/DeclCXX.h b/include/clang/AST/DeclCXX.h
index 8fde3ed257..b7854feae1 100644
--- a/include/clang/AST/DeclCXX.h
+++ b/include/clang/AST/DeclCXX.h
@@ -541,13 +541,21 @@ class CXXRecordDecl : public RecordDecl {
 
     /// \brief Retrieve the set of direct base classes.
     CXXBaseSpecifier *getBases() const {
-      return Bases.get(Definition->getASTContext().getExternalSource());
+      if (!Bases.isOffset())
+        return Bases.get(0);
+      return getBasesSlowCase();
     }
 
     /// \brief Retrieve the set of virtual base classes.
     CXXBaseSpecifier *getVBases() const {
-      return VBases.get(Definition->getASTContext().getExternalSource());
+      if (!VBases.isOffset())
+        return VBases.get(0);
+      return getVBasesSlowCase();
     }
+
+  private:
+    CXXBaseSpecifier *getBasesSlowCase() const;
+    CXXBaseSpecifier *getVBasesSlowCase() const;
   } *DefinitionData;
 
   /// \brief Describes a C++ closure type (generated by a lambda expression).
diff --git a/lib/AST/DeclCXX.cpp b/lib/AST/DeclCXX.cpp
index 4de157e9f5..11a5260836 100644
--- a/lib/AST/DeclCXX.cpp
+++ b/lib/AST/DeclCXX.cpp
@@ -60,6 +60,14 @@ CXXRecordDecl::DefinitionData::DefinitionData(CXXRecordDecl *D)
     NumVBases(0), Bases(), VBases(), Definition(D), FirstFriend(0) {
 }
 
+CXXBaseSpecifier *CXXRecordDecl::DefinitionData::getBasesSlowCase() const {
+  return Bases.get(Definition->getASTContext().getExternalSource());
+}
+
+CXXBaseSpecifier *CXXRecordDecl::DefinitionData::getVBasesSlowCase() const {
+  return VBases.get(Definition->getASTContext().getExternalSource());
+}
+
 CXXRecordDecl::CXXRecordDecl(Kind K, TagKind TK, DeclContext *DC,
                              SourceLocation StartLoc, SourceLocation IdLoc,
                              IdentifierInfo *Id, CXXRecordDecl *PrevDecl)