https://github.com/AmrDeveloper created https://github.com/llvm/llvm-project/pull/165621
Upstream Exception EhInflight op as a prerequisite for full catch handlers implementation Issue https://github.com/llvm/llvm-project/issues/154992 >From 111e875d665782a7dec55d4fd486a7852c8ea164 Mon Sep 17 00:00:00 2001 From: Amr Hesham <[email protected]> Date: Wed, 29 Oct 2025 21:01:11 +0100 Subject: [PATCH] [CIR] Upstream Exception EhInflight op --- clang/include/clang/CIR/Dialect/IR/CIROps.td | 29 +++++++ .../CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp | 82 +++++++++++++++++++ clang/test/CIR/IR/eh-inflight.cir | 15 ++++ 3 files changed, 126 insertions(+) create mode 100644 clang/test/CIR/IR/eh-inflight.cir diff --git a/clang/include/clang/CIR/Dialect/IR/CIROps.td b/clang/include/clang/CIR/Dialect/IR/CIROps.td index 2b361ed0982c6..0497d97239000 100644 --- a/clang/include/clang/CIR/Dialect/IR/CIROps.td +++ b/clang/include/clang/CIR/Dialect/IR/CIROps.td @@ -4490,6 +4490,35 @@ def CIR_TryOp : CIR_Op<"try",[ let hasLLVMLowering = false; } +//===----------------------------------------------------------------------===// +// Exception related: EhInflightOp +//===----------------------------------------------------------------------===// + +def CIR_EhInflightOp : CIR_Op<"eh.inflight_exception"> { + let summary = "Materialize the catch clause formal parameter"; + let description = [{ + `cir.eh.inflight_exception` returns two values: + - `exception_ptr`: The exception pointer for the inflight exception + - `type_id`: pointer to the exception object + This operation is expected to be the first one basic blocks on the + exception path out of `cir.try_call` operations. + + The `cleanup` attribute indicates that clean up code might run before the + values produced by this operation are used to gather exception information. + This helps CIR to pass down more accurate information for LLVM lowering + to landingpads. + }]; + + let arguments = (ins UnitAttr:$cleanup, + OptionalAttr<FlatSymbolRefArrayAttr>:$sym_type_list); + let results = (outs CIR_VoidPtrType:$exception_ptr, CIR_UInt32:$type_id); + let assemblyFormat = [{ + (`cleanup` $cleanup^)? + ($sym_type_list^)? + attr-dict + }]; +} + //===----------------------------------------------------------------------===// // Atomic operations //===----------------------------------------------------------------------===// diff --git a/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp b/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp index 5a6193fa8d840..0bf5eb740096f 100644 --- a/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp +++ b/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp @@ -3002,6 +3002,88 @@ mlir::LogicalResult CIRToLLVMAllocExceptionOpLowering::matchAndRewrite( return mlir::success(); } +static mlir::LLVM::LLVMStructType +getLLVMLandingPadStructTy(mlir::ConversionPatternRewriter &rewriter) { + // Create the landing pad type: struct { ptr, i32 } + mlir::MLIRContext *ctx = rewriter.getContext(); + auto llvmPtr = mlir::LLVM::LLVMPointerType::get(ctx); + llvm::SmallVector<mlir::Type> structFields = {llvmPtr, rewriter.getI32Type()}; + return mlir::LLVM::LLVMStructType::getLiteral(ctx, structFields); +} + +mlir::LogicalResult CIRToLLVMEhInflightOpLowering::matchAndRewrite( + cir::EhInflightOp op, OpAdaptor adaptor, + mlir::ConversionPatternRewriter &rewriter) const { + auto llvmFn = op->getParentOfType<mlir::LLVM::LLVMFuncOp>(); + assert(llvmFn && "expected LLVM function parent"); + mlir::Block *entryBlock = &llvmFn.getRegion().front(); + assert(entryBlock->isEntryBlock()); + + mlir::ArrayAttr symListAttr = op.getSymTypeListAttr(); + mlir::SmallVector<mlir::Value, 4> symAddrs; + + auto llvmPtrTy = mlir::LLVM::LLVMPointerType::get(rewriter.getContext()); + mlir::Location loc = op.getLoc(); + + // %landingpad = landingpad { ptr, i32 } + // Note that since llvm.landingpad has to be the first operation on the + // block, any needed value for its operands has to be added somewhere else. + if (symListAttr) { + // catch ptr @_ZTIi + // catch ptr @_ZTIPKc + for (mlir::Attribute attr : symListAttr) { + auto symAttr = cast<mlir::FlatSymbolRefAttr>(attr); + // Generate `llvm.mlir.addressof` for each symbol, and place those + // operations in the LLVM function entry basic block. + mlir::OpBuilder::InsertionGuard guard(rewriter); + rewriter.setInsertionPointToStart(entryBlock); + mlir::Value addrOp = mlir::LLVM::AddressOfOp::create( + rewriter, loc, llvmPtrTy, symAttr.getValue()); + symAddrs.push_back(addrOp); + } + } else if (!op.getCleanup()) { + // catch ptr null + mlir::OpBuilder::InsertionGuard guard(rewriter); + rewriter.setInsertionPointToStart(entryBlock); + mlir::Value nullOp = mlir::LLVM::ZeroOp::create(rewriter, loc, llvmPtrTy); + symAddrs.push_back(nullOp); + } + + // %slot = extractvalue { ptr, i32 } %x, 0 + // %selector = extractvalue { ptr, i32 } %x, 1 + mlir::LLVM::LLVMStructType llvmLandingPadStructTy = + getLLVMLandingPadStructTy(rewriter); + auto landingPadOp = mlir::LLVM::LandingpadOp::create( + rewriter, loc, llvmLandingPadStructTy, symAddrs); + + if (op.getCleanup()) + landingPadOp.setCleanup(true); + + mlir::Value slot = + mlir::LLVM::ExtractValueOp::create(rewriter, loc, landingPadOp, 0); + mlir::Value selector = + mlir::LLVM::ExtractValueOp::create(rewriter, loc, landingPadOp, 1); + rewriter.replaceOp(op, mlir::ValueRange{slot, selector}); + + // Landing pads are required to be in LLVM functions with personality + // attribute. + // TODO(cir): for now hardcode personality creation in order to start + // adding exception tests, once we annotate CIR with such information, + // change it to be in FuncOp lowering instead. + mlir::OpBuilder::InsertionGuard guard(rewriter); + // Insert personality decl before the current function. + rewriter.setInsertionPoint(llvmFn); + auto personalityFnTy = + mlir::LLVM::LLVMFunctionType::get(rewriter.getI32Type(), {}, + /*isVarArg=*/true); + // Get or create `__gxx_personality_v0` + const StringRef fnName = "__gxx_personality_v0"; + createLLVMFuncOpIfNotExist(rewriter, op, fnName, personalityFnTy); + llvmFn.setPersonality(fnName); + + return mlir::success(); +} + mlir::LogicalResult CIRToLLVMTrapOpLowering::matchAndRewrite( cir::TrapOp op, OpAdaptor adaptor, mlir::ConversionPatternRewriter &rewriter) const { diff --git a/clang/test/CIR/IR/eh-inflight.cir b/clang/test/CIR/IR/eh-inflight.cir new file mode 100644 index 0000000000000..90a5f3f67b6fe --- /dev/null +++ b/clang/test/CIR/IR/eh-inflight.cir @@ -0,0 +1,15 @@ +// RUN: cir-opt %s --verify-roundtrip | FileCheck %s + +module { + +cir.func dso_local @function_with_inflight_exception() { + %exception_ptr, %type_id = cir.eh.inflight_exception + cir.return +} + +// CHECK: cir.func dso_local @function_with_inflight_exception() { +// CHECK: %exception_ptr, %type_id = cir.eh.inflight_exception +// CHECK: cir.return +// CHECK: } + +} _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
