[clang] [CIR][NFC] Upstream bulk handling for Decl kinds (PR #138319)

[Andy Kaylor via cfe-commits]

https://github.com/andykaylor created https://github.com/llvm/llvm-project/pull/138319

This adds explicit case statements for Decl types that weren't explicitly present in the emitDecl function. Those that need no handling are just accepted. Those that will need handling still go to errorNYI, but the default statement is removed.

>From f3d517fe27568d64a2ae63ad328aa83b6a19c568 Mon Sep 17 00:00:00 2001
From: Andy Kaylor <akaylor at nvidia.com>
Date: Fri, 25 Apr 2025 08:30:58 -0700
Subject: [PATCH] [CIR][NFC] Upstream bulk handling for Decl kinds

This adds explicit case statements for Decl types that weren't
explicitly present in the emitDecl function. Those that need no
handling are just accepted. Those that will need handling still
go to errorNYI, but the default statement is removed.
---
 clang/lib/CIR/CodeGen/CIRGenDecl.cpp | 86 +++++++++++++++++++++++++++-
 1 file changed, 84 insertions(+), 2 deletions(-)

diff --git a/clang/lib/CIR/CodeGen/CIRGenDecl.cpp b/clang/lib/CIR/CodeGen/CIRGenDecl.cpp
index 90498cd18f46b..498d7533c2204 100644
--- a/clang/lib/CIR/CodeGen/CIRGenDecl.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenDecl.cpp
@@ -268,11 +268,87 @@ void CIRGenFunction::emitExprAsInit(const Expr *init, const ValueDecl *d,
 
 void CIRGenFunction::emitDecl(const Decl &d) {
   switch (d.getKind()) {
-  case Decl::LinkageSpec:
+  case Decl::BuiltinTemplate:
+  case Decl::TranslationUnit:
+  case Decl::ExternCContext:
   case Decl::Namespace:
+  case Decl::UnresolvedUsingTypename:
+  case Decl::ClassTemplateSpecialization:
+  case Decl::ClassTemplatePartialSpecialization:
+  case Decl::VarTemplateSpecialization:
+  case Decl::VarTemplatePartialSpecialization:
+  case Decl::TemplateTypeParm:
+  case Decl::UnresolvedUsingValue:
+  case Decl::NonTypeTemplateParm:
+  case Decl::CXXDeductionGuide:
+  case Decl::CXXMethod:
+  case Decl::CXXConstructor:
+  case Decl::CXXDestructor:
+  case Decl::CXXConversion:
+  case Decl::Field:
+  case Decl::MSProperty:
+  case Decl::IndirectField:
+  case Decl::ObjCIvar:
+  case Decl::ObjCAtDefsField:
+  case Decl::ParmVar:
+  case Decl::ImplicitParam:
+  case Decl::ClassTemplate:
+  case Decl::VarTemplate:
+  case Decl::FunctionTemplate:
+  case Decl::TypeAliasTemplate:
+  case Decl::TemplateTemplateParm:
+  case Decl::ObjCMethod:
+  case Decl::ObjCCategory:
+  case Decl::ObjCProtocol:
+  case Decl::ObjCInterface:
+  case Decl::ObjCCategoryImpl:
+  case Decl::ObjCImplementation:
+  case Decl::ObjCProperty:
+  case Decl::ObjCCompatibleAlias:
+  case Decl::PragmaComment:
+  case Decl::PragmaDetectMismatch:
+  case Decl::AccessSpec:
+  case Decl::LinkageSpec:
+  case Decl::Export:
+  case Decl::ObjCPropertyImpl:
+  case Decl::FileScopeAsm:
+  case Decl::Friend:
+  case Decl::FriendTemplate:
+  case Decl::Block:
+  case Decl::OutlinedFunction:
+  case Decl::Captured:
+  case Decl::UsingShadow:
+  case Decl::ConstructorUsingShadow:
+  case Decl::ObjCTypeParam:
+  case Decl::Binding:
+  case Decl::UnresolvedUsingIfExists:
     llvm_unreachable("Declaration should not be in declstmts!");
 
+  case Decl::Function:     // void X();
+  case Decl::EnumConstant: // enum ? { X = ? }
+  case Decl::StaticAssert: // static_assert(X, ""); [C++0x]
+  case Decl::Label:        // __label__ x;
+  case Decl::Import:
+  case Decl::MSGuid: // __declspec(uuid("..."))
+  case Decl::TemplateParamObject:
+  case Decl::OMPThreadPrivate:
+  case Decl::OMPAllocate:
+  case Decl::OMPCapturedExpr:
+  case Decl::OMPRequires:
+  case Decl::Empty:
+  case Decl::Concept:
+  case Decl::LifetimeExtendedTemporary:
+  case Decl::RequiresExprBody:
+  case Decl::UnnamedGlobalConstant:
+    // None of these decls require codegen support.
+    return;
+
+  case Decl::Enum:   // enum X;
   case Decl::Record: // struct/union/class X;
+  case Decl::CXXRecord: // struct/union/class X; [C++]
+  case Decl::NamespaceAlias:
+  case Decl::Using:          // using X; [C++]
+  case Decl::UsingEnum:      // using enum X; [C++]
   case Decl::UsingDirective: // using namespace X; [C++]
     assert(!cir::MissingFeatures::generateDebugInfo());
     return;
@@ -297,7 +373,13 @@ void CIRGenFunction::emitDecl(const Decl &d) {
       cgm.errorNYI(d.getSourceRange(), "emitDecl: variably modified type");
     return;
   }
-  default:
+  case Decl::ImplicitConceptSpecialization:
+  case Decl::HLSLBuffer:
+  case Decl::TopLevelStmt:
+  case Decl::UsingPack:
+  case Decl::Decomposition: // This could be moved to join Decl::Var
+  case Decl::OMPDeclareReduction:
+  case Decl::OMPDeclareMapper:
     cgm.errorNYI(d.getSourceRange(),
                  std::string("emitDecl: unhandled decl type: ") +
                      d.getDeclKindName());