[CIR][Lowering][TBAA] distinct C and C++ (#1406)

Author: PikachuHyA

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

@@ -14,8 +14,8 @@ namespace direct {
 
 class CIRToLLVMTBAAAttrLowering {
 public:
-  CIRToLLVMTBAAAttrLowering(mlir::MLIRContext *mlirContext)
-      : mlirContext(mlirContext) {}
+  CIRToLLVMTBAAAttrLowering(mlir::MLIRContext *mlirContext, bool isCPlusPlus)
+      : mlirContext(mlirContext), isCPlusPlus(isCPlusPlus) {}
 
   mlir::LLVM::TBAATypeDescriptorAttr
   lowerCIRTBAAAttrToLLVMTBAAAttr(mlir::Attribute tbaa) {
@@ -44,6 +44,9 @@ class CIRToLLVMTBAAAttrLowering {
 
 private:
   mlir::LLVM::TBAARootAttr getRoot() {
+    if (isCPlusPlus)
+      return createTBAARoot("Simple C++ TBAA");
+
     return createTBAARoot("Simple C/C++ TBAA");
   }
 
@@ -67,13 +70,16 @@ class CIRToLLVMTBAAAttrLowering {
   }
 
   mlir::MLIRContext *mlirContext;
+  bool isCPlusPlus;
 };
 
 mlir::ArrayAttr lowerCIRTBAAAttr(mlir::Attribute tbaa,
                                  mlir::ConversionPatternRewriter &rewriter,
                                  cir::LowerModule *lowerMod) {
   auto *ctx = rewriter.getContext();
-  CIRToLLVMTBAAAttrLowering lower(ctx);
+  auto langAttr = mlir::cast<cir::LangAttr>(
+      lowerMod->getModule()->getAttr(cir::CIRDialect::getLangAttrName()));
+  CIRToLLVMTBAAAttrLowering lower(ctx, langAttr.isCXX());
   if (auto tbaaTag = mlir::dyn_cast<cir::TBAATagAttr>(tbaa)) {
     mlir::LLVM::TBAATypeDescriptorAttr accessType =
         lower.lowerCIRTBAAAttrToLLVMTBAAAttr(tbaaTag.getAccess());

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

@@ -4742,8 +4742,6 @@ void ConvertCIRToLLVMPass::runOnOperation() {
   // Allow operations that will be lowered directly to LLVM IR.
   target.addLegalOp<mlir::LLVM::ZeroOp>();
 
-  processCIRAttrs(module);
-
   llvm::SmallVector<mlir::Operation *> ops;
   ops.push_back(module);
   collect_unreachable(module, ops);
@@ -4770,6 +4768,8 @@ void ConvertCIRToLLVMPass::runOnOperation() {
                                             dtorAttr.getPriority());
                     });
   buildGlobalAnnotationsVar(stringGlobalsMap, argStringGlobalsMap, argsVarMap);
+
+  processCIRAttrs(module);
 }
 
 std::unique_ptr<mlir::Pass> createConvertCIRToLLVMPass() {

clang/test/CIR/CodeGen/tbaa-struct.cpp

@@ -380,7 +380,7 @@ uint32_t g15(StructS *S, StructS3 *S3, uint64_t count) {
 // OLD-PATH: [[TAG_i32]] = !{[[TYPE_INT:!.*]], [[TYPE_INT]], i64 0}
 // OLD-PATH: [[TYPE_INT]] = !{!"int", [[TYPE_CHAR:!.*]], i64 0}
 // OLD-PATH: [[TYPE_CHAR]] = !{!"omnipotent char", [[TAG_cxx_tbaa:!.*]],
-// OLD-PATH: [[TAG_cxx_tbaa]] = !{!"Simple C/C++ TBAA"}
+// OLD-PATH: [[TAG_cxx_tbaa]] = !{!"Simple C++ TBAA"}
 // OLD-PATH: [[TAG_A_f32]] = !{[[TYPE_A:!.*]], [[TYPE_INT]], i64 4}
 // OLD-PATH: [[TYPE_A]] = !{!"_ZTS7StructA", [[TYPE_SHORT:!.*]], i64 0, [[TYPE_INT]], i64 4, [[TYPE_SHORT]], i64 8, [[TYPE_INT]], i64 12}
 // OLD-PATH: [[TYPE_SHORT:!.*]] = !{!"short", [[TYPE_CHAR]]