[CIR] Add attribute visitor for lowering globals

clang/include/clang/CIR/Dialect/IR/CIRAttrVisitor.h

@@ -0,0 +1,47 @@
+//===- CIRAttrVisitor.h - Visitor for CIR attributes ------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the CirAttrVisitor interface.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_CIR_DIALECT_IR_CIRATTRVISITOR_H
+#define LLVM_CLANG_CIR_DIALECT_IR_CIRATTRVISITOR_H
+
+#include "clang/CIR/Dialect/IR/CIRAttrs.h"
+
+namespace cir {
+
+#define DISPATCH(NAME) return getImpl()->visitCir##NAME(cirAttr);
+
+template <typename ImplClass, typename RetTy> class CirAttrVisitor {
+public:
+  RetTy visit(mlir::Attribute attr) {
+#define ATTRDEF(NAME)                                                          \
+  if (const auto cirAttr = mlir::dyn_cast<cir::NAME>(attr))                    \
+    DISPATCH(NAME);
+#include "clang/CIR/Dialect/IR/CIRAttrDefsList.inc"
+    llvm_unreachable("unhandled attribute type");
+  }
+
+  // If the implementation chooses not to implement a certain visit
+  // method, fall back to the parent.
+#define ATTRDEF(NAME)                                                          \
+  RetTy visitCir##NAME(NAME cirAttr) { DISPATCH(Attr); }
+#include "clang/CIR/Dialect/IR/CIRAttrDefsList.inc"
+
+  RetTy visitCirAttr(mlir::Attribute attr) { return RetTy(); }
+
+  ImplClass *getImpl() { return static_cast<ImplClass *>(this); }
+};
+
+#undef DISPATCH
+
+} // namespace cir
+
+#endif // LLVM_CLANG_CIR_DIALECT_IR_CIRATTRVISITOR_H

clang/include/clang/CIR/Dialect/IR/CMakeLists.txt

@@ -26,6 +26,7 @@ mlir_tablegen(CIROpsStructs.h.inc -gen-attrdef-decls)
 mlir_tablegen(CIROpsStructs.cpp.inc -gen-attrdef-defs)
 mlir_tablegen(CIROpsAttributes.h.inc -gen-attrdef-decls)
 mlir_tablegen(CIROpsAttributes.cpp.inc -gen-attrdef-defs)
+mlir_tablegen(CIRAttrDefsList.inc -gen-attrdef-list)
 add_public_tablegen_target(MLIRCIREnumsGen)
 
 clang_tablegen(CIRBuiltinsLowering.inc -gen-cir-builtins-lowering

clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp

@@ -41,6 +41,7 @@
 #include "mlir/Target/LLVMIR/Dialect/LLVMIR/LLVMToLLVMIRTranslation.h"
 #include "mlir/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.h"
 #include "mlir/Target/LLVMIR/Export.h"
+#include "clang/CIR/Dialect/IR/CIRAttrVisitor.h"
 #include "clang/CIR/Dialect/Passes.h"
 #include "clang/CIR/LoweringHelpers.h"
 #include "clang/CIR/MissingFeatures.h"
@@ -425,32 +426,52 @@ emitCirAttrToMemory(mlir::Operation *parentOp, mlir::Attribute attr,
 }
 
 /// Switches on the type of attribute and calls the appropriate conversion.
+class CirAttrToValue : public CirAttrVisitor<CirAttrToValue, mlir::Value> {
+public:
+  CirAttrToValue(mlir::Operation *parentOp,
+                 mlir::ConversionPatternRewriter &rewriter,
+                 const mlir::TypeConverter *converter,
+                 mlir::DataLayout const &dataLayout)
+      : parentOp(parentOp), rewriter(rewriter), converter(converter),
+        dataLayout(dataLayout) {}
+
+  mlir::Value visitCirIntAttr(cir::IntAttr attr);
+  mlir::Value visitCirFPAttr(cir::FPAttr attr);
+  mlir::Value visitCirConstPtrAttr(cir::ConstPtrAttr attr);
+  mlir::Value visitCirConstStructAttr(cir::ConstStructAttr attr);
+  mlir::Value visitCirConstArrayAttr(cir::ConstArrayAttr attr);
+  mlir::Value visitCirConstVectorAttr(cir::ConstVectorAttr attr);
+  mlir::Value visitCirBoolAttr(cir::BoolAttr attr);
+  mlir::Value visitCirZeroAttr(cir::ZeroAttr attr);
+  mlir::Value visitCirUndefAttr(cir::UndefAttr attr);
+  mlir::Value visitCirPoisonAttr(cir::PoisonAttr attr);
+  mlir::Value visitCirGlobalViewAttr(cir::GlobalViewAttr attr);
+  mlir::Value visitCirVTableAttr(cir::VTableAttr attr);
+  mlir::Value visitCirTypeInfoAttr(cir::TypeInfoAttr attr);
+
+private:
+  mlir::Operation *parentOp;
+  mlir::ConversionPatternRewriter &rewriter;
+  const mlir::TypeConverter *converter;
+  mlir::DataLayout const &dataLayout;
+};
 
 /// IntAttr visitor.
-static mlir::Value
-lowerCirAttrAsValue(mlir::Operation *parentOp, cir::IntAttr intAttr,
-                    mlir::ConversionPatternRewriter &rewriter,
-                    const mlir::TypeConverter *converter) {
+mlir::Value CirAttrToValue::visitCirIntAttr(cir::IntAttr intAttr) {
   auto loc = parentOp->getLoc();
   return rewriter.create<mlir::LLVM::ConstantOp>(
       loc, converter->convertType(intAttr.getType()), intAttr.getValue());
 }
 
 /// BoolAttr visitor.
-static mlir::Value
-lowerCirAttrAsValue(mlir::Operation *parentOp, cir::BoolAttr boolAttr,
-                    mlir::ConversionPatternRewriter &rewriter,
-                    const mlir::TypeConverter *converter) {
+mlir::Value CirAttrToValue::visitCirBoolAttr(cir::BoolAttr boolAttr) {
   auto loc = parentOp->getLoc();
   return rewriter.create<mlir::LLVM::ConstantOp>(
       loc, converter->convertType(boolAttr.getType()), boolAttr.getValue());
 }
 
 /// ConstPtrAttr visitor.
-static mlir::Value
-lowerCirAttrAsValue(mlir::Operation *parentOp, cir::ConstPtrAttr ptrAttr,
-                    mlir::ConversionPatternRewriter &rewriter,
-                    const mlir::TypeConverter *converter) {
+mlir::Value CirAttrToValue::visitCirConstPtrAttr(cir::ConstPtrAttr ptrAttr) {
   auto loc = parentOp->getLoc();
   if (ptrAttr.isNullValue()) {
     return rewriter.create<mlir::LLVM::ZeroOp>(
@@ -465,51 +486,36 @@ lowerCirAttrAsValue(mlir::Operation *parentOp, cir::ConstPtrAttr ptrAttr,
 }
 
 /// FPAttr visitor.
-static mlir::Value
-lowerCirAttrAsValue(mlir::Operation *parentOp, cir::FPAttr fltAttr,
-                    mlir::ConversionPatternRewriter &rewriter,
-                    const mlir::TypeConverter *converter) {
+mlir::Value CirAttrToValue::visitCirFPAttr(cir::FPAttr fltAttr) {
   auto loc = parentOp->getLoc();
   return rewriter.create<mlir::LLVM::ConstantOp>(
       loc, converter->convertType(fltAttr.getType()), fltAttr.getValue());
 }
 
 /// ZeroAttr visitor.
-static mlir::Value
-lowerCirAttrAsValue(mlir::Operation *parentOp, cir::ZeroAttr zeroAttr,
-                    mlir::ConversionPatternRewriter &rewriter,
-                    const mlir::TypeConverter *converter) {
+mlir::Value CirAttrToValue::visitCirZeroAttr(cir::ZeroAttr zeroAttr) {
   auto loc = parentOp->getLoc();
   return rewriter.create<mlir::LLVM::ZeroOp>(
       loc, converter->convertType(zeroAttr.getType()));
 }
 
 /// UndefAttr visitor.
-static mlir::Value
-lowerCirAttrAsValue(mlir::Operation *parentOp, cir::UndefAttr undefAttr,
-                    mlir::ConversionPatternRewriter &rewriter,
-                    const mlir::TypeConverter *converter) {
+mlir::Value CirAttrToValue::visitCirUndefAttr(cir::UndefAttr undefAttr) {
   auto loc = parentOp->getLoc();
   return rewriter.create<mlir::LLVM::UndefOp>(
       loc, converter->convertType(undefAttr.getType()));
 }
 
 /// PoisonAttr visitor.
-static mlir::Value
-lowerCirAttrAsValue(mlir::Operation *parentOp, cir::PoisonAttr poisonAttr,
-                    mlir::ConversionPatternRewriter &rewriter,
-                    const mlir::TypeConverter *converter) {
+mlir::Value CirAttrToValue::visitCirPoisonAttr(cir::PoisonAttr poisonAttr) {
   auto loc = parentOp->getLoc();
   return rewriter.create<mlir::LLVM::PoisonOp>(
       loc, converter->convertType(poisonAttr.getType()));
 }
 
 /// ConstStruct visitor.
-static mlir::Value
-lowerCirAttrAsValue(mlir::Operation *parentOp, cir::ConstStructAttr constStruct,
-                    mlir::ConversionPatternRewriter &rewriter,
-                    const mlir::TypeConverter *converter,
-                    mlir::DataLayout const &dataLayout) {
+mlir::Value
+CirAttrToValue::visitCirConstStructAttr(cir::ConstStructAttr constStruct) {
   auto llvmTy = converter->convertType(constStruct.getType());
   auto loc = parentOp->getLoc();
   mlir::Value result = rewriter.create<mlir::LLVM::UndefOp>(loc, llvmTy);
@@ -525,49 +531,37 @@ lowerCirAttrAsValue(mlir::Operation *parentOp, cir::ConstStructAttr constStruct,
 }
 
 // VTableAttr visitor.
-static mlir::Value
-lowerCirAttrAsValue(mlir::Operation *parentOp, cir::VTableAttr vtableArr,
-                    mlir::ConversionPatternRewriter &rewriter,
-                    const mlir::TypeConverter *converter,
-                    mlir::DataLayout const &dataLayout) {
+mlir::Value CirAttrToValue::visitCirVTableAttr(cir::VTableAttr vtableArr) {
   auto llvmTy = converter->convertType(vtableArr.getType());
   auto loc = parentOp->getLoc();
   mlir::Value result = rewriter.create<mlir::LLVM::UndefOp>(loc, llvmTy);
 
   for (auto [idx, elt] : llvm::enumerate(vtableArr.getVtableData())) {
-    mlir::Value init =
-        lowerCirAttrAsValue(parentOp, elt, rewriter, converter, dataLayout);
+    mlir::Value init = visit(elt);
     result = rewriter.create<mlir::LLVM::InsertValueOp>(loc, result, init, idx);
   }
 
   return result;
 }
 
 // TypeInfoAttr visitor.
-static mlir::Value
-lowerCirAttrAsValue(mlir::Operation *parentOp, cir::TypeInfoAttr typeinfoArr,
-                    mlir::ConversionPatternRewriter &rewriter,
-                    const mlir::TypeConverter *converter,
-                    mlir::DataLayout const &dataLayout) {
+mlir::Value
+CirAttrToValue::visitCirTypeInfoAttr(cir::TypeInfoAttr typeinfoArr) {
   auto llvmTy = converter->convertType(typeinfoArr.getType());
   auto loc = parentOp->getLoc();
   mlir::Value result = rewriter.create<mlir::LLVM::UndefOp>(loc, llvmTy);
 
   for (auto [idx, elt] : llvm::enumerate(typeinfoArr.getData())) {
-    mlir::Value init =
-        lowerCirAttrAsValue(parentOp, elt, rewriter, converter, dataLayout);
+    mlir::Value init = visit(elt);
     result = rewriter.create<mlir::LLVM::InsertValueOp>(loc, result, init, idx);
   }
 
   return result;
 }
 
 // ConstArrayAttr visitor
-static mlir::Value
-lowerCirAttrAsValue(mlir::Operation *parentOp, cir::ConstArrayAttr constArr,
-                    mlir::ConversionPatternRewriter &rewriter,
-                    const mlir::TypeConverter *converter,
-                    mlir::DataLayout const &dataLayout) {
+mlir::Value
+CirAttrToValue::visitCirConstArrayAttr(cir::ConstArrayAttr constArr) {
   auto llvmTy = converter->convertType(constArr.getType());
   auto loc = parentOp->getLoc();
   mlir::Value result;
@@ -610,10 +604,8 @@ lowerCirAttrAsValue(mlir::Operation *parentOp, cir::ConstArrayAttr constArr,
 }
 
 // ConstVectorAttr visitor.
-static mlir::Value
-lowerCirAttrAsValue(mlir::Operation *parentOp, cir::ConstVectorAttr constVec,
-                    mlir::ConversionPatternRewriter &rewriter,
-                    const mlir::TypeConverter *converter) {
+mlir::Value
+CirAttrToValue::visitCirConstVectorAttr(cir::ConstVectorAttr constVec) {
   auto llvmTy = converter->convertType(constVec.getType());
   auto loc = parentOp->getLoc();
   SmallVector<mlir::Attribute> mlirValues;
@@ -638,11 +630,8 @@ lowerCirAttrAsValue(mlir::Operation *parentOp, cir::ConstVectorAttr constVec,
 }
 
 // GlobalViewAttr visitor.
-static mlir::Value
-lowerCirAttrAsValue(mlir::Operation *parentOp, cir::GlobalViewAttr globalAttr,
-                    mlir::ConversionPatternRewriter &rewriter,
-                    const mlir::TypeConverter *converter,
-                    mlir::DataLayout const &dataLayout) {
+mlir::Value
+CirAttrToValue::visitCirGlobalViewAttr(cir::GlobalViewAttr globalAttr) {
   auto module = parentOp->getParentOfType<mlir::ModuleOp>();
   mlir::Type sourceType;
   unsigned sourceAddrSpace = 0;
@@ -716,43 +705,16 @@ lowerCirAttrAsValue(mlir::Operation *parentOp, cir::GlobalViewAttr globalAttr,
 }
 
 /// Switches on the type of attribute and calls the appropriate conversion.
-mlir::Value lowerCirAttrAsValue(mlir::Operation *parentOp, mlir::Attribute attr,
+mlir::Value lowerCirAttrAsValue(mlir::Operation *parentOp,
+                                const mlir::Attribute attr,
                                 mlir::ConversionPatternRewriter &rewriter,
                                 const mlir::TypeConverter *converter,
                                 mlir::DataLayout const &dataLayout) {
-  if (const auto intAttr = mlir::dyn_cast<cir::IntAttr>(attr))
-    return lowerCirAttrAsValue(parentOp, intAttr, rewriter, converter);
-  if (const auto fltAttr = mlir::dyn_cast<cir::FPAttr>(attr))
-    return lowerCirAttrAsValue(parentOp, fltAttr, rewriter, converter);
-  if (const auto ptrAttr = mlir::dyn_cast<cir::ConstPtrAttr>(attr))
-    return lowerCirAttrAsValue(parentOp, ptrAttr, rewriter, converter);
-  if (const auto constStruct = mlir::dyn_cast<cir::ConstStructAttr>(attr))
-    return lowerCirAttrAsValue(parentOp, constStruct, rewriter, converter,
-                               dataLayout);
-  if (const auto constArr = mlir::dyn_cast<cir::ConstArrayAttr>(attr))
-    return lowerCirAttrAsValue(parentOp, constArr, rewriter, converter,
-                               dataLayout);
-  if (const auto constVec = mlir::dyn_cast<cir::ConstVectorAttr>(attr))
-    return lowerCirAttrAsValue(parentOp, constVec, rewriter, converter);
-  if (const auto boolAttr = mlir::dyn_cast<cir::BoolAttr>(attr))
-    return lowerCirAttrAsValue(parentOp, boolAttr, rewriter, converter);
-  if (const auto zeroAttr = mlir::dyn_cast<cir::ZeroAttr>(attr))
-    return lowerCirAttrAsValue(parentOp, zeroAttr, rewriter, converter);
-  if (const auto undefAttr = mlir::dyn_cast<cir::UndefAttr>(attr))
-    return lowerCirAttrAsValue(parentOp, undefAttr, rewriter, converter);
-  if (const auto poisonAttr = mlir::dyn_cast<cir::PoisonAttr>(attr))
-    return lowerCirAttrAsValue(parentOp, poisonAttr, rewriter, converter);
-  if (const auto globalAttr = mlir::dyn_cast<cir::GlobalViewAttr>(attr))
-    return lowerCirAttrAsValue(parentOp, globalAttr, rewriter, converter,
-                               dataLayout);
-  if (const auto vtableAttr = mlir::dyn_cast<cir::VTableAttr>(attr))
-    return lowerCirAttrAsValue(parentOp, vtableAttr, rewriter, converter,
-                               dataLayout);
-  if (const auto typeinfoAttr = mlir::dyn_cast<cir::TypeInfoAttr>(attr))
-    return lowerCirAttrAsValue(parentOp, typeinfoAttr, rewriter, converter,
-                               dataLayout);
-
-  llvm_unreachable("unhandled attribute type");
+  CirAttrToValue valueConverter(parentOp, rewriter, converter, dataLayout);
+  auto value = valueConverter.visit(attr);
+  if (!value)
+    llvm_unreachable("unhandled attribute type");
+  return value;
 }
 
 //===----------------------------------------------------------------------===//
@@ -1734,8 +1696,8 @@ mlir::LogicalResult CIRToLLVMConstantOpLowering::matchAndRewrite(
   // Regardless of the type, we should lower the constant of poison value
   // into PoisonOp.
   if (auto poisonAttr = mlir::dyn_cast<cir::PoisonAttr>(attr)) {
-    rewriter.replaceOp(
-        op, lowerCirAttrAsValue(op, poisonAttr, rewriter, getTypeConverter()));
+    rewriter.replaceOp(op, lowerCirAttrAsValue(op, poisonAttr, rewriter,
+                                               getTypeConverter(), dataLayout));
     return mlir::success();
   }
 

clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.h

@@ -22,7 +22,8 @@ namespace direct {
 
 /// Convert a CIR attribute to an LLVM attribute. May use the datalayout for
 /// lowering attributes to-be-stored in memory.
-mlir::Value lowerCirAttrAsValue(mlir::Operation *parentOp, mlir::Attribute attr,
+mlir::Value lowerCirAttrAsValue(mlir::Operation *parentOp,
+                                const mlir::Attribute attr,
                                 mlir::ConversionPatternRewriter &rewriter,
                                 const mlir::TypeConverter *converter,
                                 mlir::DataLayout const &dataLayout);

mlir/test/mlir-tblgen/attrdefs.td

@@ -1,5 +1,6 @@
 // RUN: mlir-tblgen -gen-attrdef-decls -I %S/../../include %s | FileCheck %s --check-prefix=DECL
 // RUN: mlir-tblgen -gen-attrdef-defs -I %S/../../include %s | FileCheck %s --check-prefix=DEF
+// RUN: mlir-tblgen -gen-attrdef-list -I %S/../../include %s | FileCheck %s --check-prefix=LIST
 
 include "mlir/IR/AttrTypeBase.td"
 include "mlir/IR/OpBase.td"
@@ -19,6 +20,13 @@ include "mlir/IR/OpBase.td"
 // DEF: ::test::CompoundAAttr,
 // DEF: ::test::SingleParameterAttr
 
+// LIST: ATTRDEF(IndexAttr)
+// LIST: ATTRDEF(SimpleAAttr)
+// LIST: ATTRDEF(CompoundAAttr)
+// LIST: ATTRDEF(SingleParameterAttr)
+
+// LIST: #undef ATTRDEF
+
 // DEF-LABEL: ::mlir::OptionalParseResult generatedAttributeParser(
 // DEF-SAME: ::mlir::AsmParser &parser,
 // DEF-SAME: ::llvm::StringRef *mnemonic, ::mlir::Type type,