[clang] acc80ea - [AST] Cleanup on getting the underlying decl of using-shdow decl.

[Haojian Wu via cfe-commits]

Author: Haojian Wu
Date: 2022-05-16T13:58:08+02:00
New Revision: acc80ea71bac51458df9d75552651e7c161db64b

URL: https://github.com/llvm/llvm-project/commit/acc80ea71bac51458df9d75552651e7c161db64b
DIFF: https://github.com/llvm/llvm-project/commit/acc80ea71bac51458df9d75552651e7c161db64b.diff

LOG: [AST] Cleanup on getting the underlying decl of using-shdow decl.

This should be a NFC cleanup. It removes a unnecessary loop to get the underlying
decl, and add an assertion.

The underlying decl of a using-shadow decl is always the original declaration
has been brought into the scope, clang never builds a nested using-shadow
decl (see Sema::BuildUsingShadowDecl).

Reviewed By: sammccall

Differential Revision: https://reviews.llvm.org/D123422

Added: 
    

Modified: 
    clang/lib/AST/Decl.cpp
    clang/lib/AST/DeclCXX.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 911479bee5ff9..1c5c64d1b3650 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -1851,7 +1851,7 @@ bool NamedDecl::hasLinkage() const {
 
 NamedDecl *NamedDecl::getUnderlyingDeclImpl() {
   NamedDecl *ND = this;
-  while (auto *UD = dyn_cast<UsingShadowDecl>(ND))
+  if (auto *UD = dyn_cast<UsingShadowDecl>(ND))
     ND = UD->getTargetDecl();
 
   if (auto *AD = dyn_cast<ObjCCompatibleAliasDecl>(ND))

diff  --git a/clang/lib/AST/DeclCXX.cpp b/clang/lib/AST/DeclCXX.cpp
index cb6a355f7294a..020c7da52041d 100644
--- a/clang/lib/AST/DeclCXX.cpp
+++ b/clang/lib/AST/DeclCXX.cpp
@@ -2968,8 +2968,10 @@ UsingShadowDecl::UsingShadowDecl(Kind K, ASTContext &C, DeclContext *DC,
                                  BaseUsingDecl *Introducer, NamedDecl *Target)
     : NamedDecl(K, DC, Loc, Name), redeclarable_base(C),
       UsingOrNextShadow(Introducer) {
-  if (Target)
+  if (Target) {
+    assert(!isa<UsingShadowDecl>(Target));
     setTargetDecl(Target);
+  }
   setImplicit();
 }