Author: Andy Kaylor Date: 2025-11-24T22:48:55Z New Revision: 435dbbacad475b12b6cae0a8296e8a46ea684812
URL: https://github.com/llvm/llvm-project/commit/435dbbacad475b12b6cae0a8296e8a46ea684812 DIFF: https://github.com/llvm/llvm-project/commit/435dbbacad475b12b6cae0a8296e8a46ea684812.diff LOG: [CIR] Fix a problem with global array dtor lowering (#169416) In the LoweringPrepare pass, the handling for global array destructor lowering was mishandling the insertion point, so that if this code needed to create a declaration for the __cxa_atexit function, that declaration was being created in the dtor region, rather than at module scope. This change fixes that. Added: clang/test/CIR/CodeGen/global-array-dtor.cpp Modified: clang/lib/CIR/Dialect/Transforms/LoweringPrepare.cpp Removed: ################################################################################ diff --git a/clang/lib/CIR/Dialect/Transforms/LoweringPrepare.cpp b/clang/lib/CIR/Dialect/Transforms/LoweringPrepare.cpp index f8f354c2d1072..cedc2a73b9260 100644 --- a/clang/lib/CIR/Dialect/Transforms/LoweringPrepare.cpp +++ b/clang/lib/CIR/Dialect/Transforms/LoweringPrepare.cpp @@ -702,6 +702,7 @@ cir::FuncOp LoweringPreparePass::getOrCreateDtorFunc(CIRBaseBuilderTy &builder, cir::GlobalOp op, mlir::Region &dtorRegion, cir::CallOp &dtorCall) { + mlir::OpBuilder::InsertionGuard guard(builder); assert(!cir::MissingFeatures::astVarDeclInterface()); assert(!cir::MissingFeatures::opGlobalThreadLocal()); diff --git a/clang/test/CIR/CodeGen/global-array-dtor.cpp b/clang/test/CIR/CodeGen/global-array-dtor.cpp new file mode 100644 index 0000000000000..01277a3f34015 --- /dev/null +++ b/clang/test/CIR/CodeGen/global-array-dtor.cpp @@ -0,0 +1,113 @@ +// RUN: %clang_cc1 -std=c++17 -triple x86_64-unknown-linux-gnu -fclangir -emit-cir -mmlir --mlir-print-ir-before=cir-lowering-prepare %s -o %t.cir 2> %t-before.cir +// RUN: FileCheck --input-file=%t-before.cir %s --check-prefix=CIR-BEFORE-LPP +// RUN: FileCheck --input-file=%t.cir %s --check-prefix=CIR +// RUN: %clang_cc1 -std=c++17 -triple x86_64-unknown-linux-gnu -fclangir -emit-llvm %s -o %t-cir.ll +// RUN: FileCheck --input-file=%t-cir.ll %s --check-prefix=LLVM +// RUN: %clang_cc1 -std=c++17 -triple x86_64-unknown-linux-gnu -emit-llvm %s -o %t.ll +// RUN: FileCheck --input-file=%t.ll %s --check-prefix=OGCG + +// This duplicates a test case in global-init.cpp, but having it by itself +// forces the __cxa_atexit function to be emitted for this case, which was +// broken in the original implementation. + +struct ArrayDtor { + ~ArrayDtor(); +}; + +ArrayDtor arrDtor[16]; + +// CIR-BEFORE-LPP: cir.global external @arrDtor = #cir.zero : !cir.array<!rec_ArrayDtor x 16> +// CIR-BEFORE-LPP-SAME: dtor { +// CIR-BEFORE-LPP: %[[THIS:.*]] = cir.get_global @arrDtor : !cir.ptr<!cir.array<!rec_ArrayDtor x 16>> +// CIR-BEFORE-LPP: cir.array.dtor %[[THIS]] : !cir.ptr<!cir.array<!rec_ArrayDtor x 16>> { +// CIR-BEFORE-LPP: ^bb0(%[[ELEM:.*]]: !cir.ptr<!rec_ArrayDtor>): +// CIR-BEFORE-LPP: cir.call @_ZN9ArrayDtorD1Ev(%[[ELEM]]) nothrow : (!cir.ptr<!rec_ArrayDtor>) -> () +// CIR-BEFORE-LPP: cir.yield +// CIR-BEFORE-LPP: } +// CIR-BEFORE-LPP: } + +// CIR: cir.global external @arrDtor = #cir.zero : !cir.array<!rec_ArrayDtor x 16> {alignment = 16 : i64} +// CIR: cir.func internal private @__cxx_global_array_dtor(%[[ARR_ARG:.*]]: !cir.ptr<!void> {{.*}}) { +// CIR: %[[CONST15:.*]] = cir.const #cir.int<15> : !u64i +// CIR: %[[BEGIN:.*]] = cir.cast array_to_ptrdecay %[[ARR_ARG]] : !cir.ptr<!void> -> !cir.ptr<!rec_ArrayDtor> +// CIR: %[[END:.*]] = cir.ptr_stride %[[BEGIN]], %[[CONST15]] : (!cir.ptr<!rec_ArrayDtor>, !u64i) -> !cir.ptr<!rec_ArrayDtor> +// CIR: %[[CUR_ADDR:.*]] = cir.alloca !cir.ptr<!rec_ArrayDtor>, !cir.ptr<!cir.ptr<!rec_ArrayDtor>>, ["__array_idx"] +// CIR: cir.store %[[END]], %[[CUR_ADDR]] : !cir.ptr<!rec_ArrayDtor>, !cir.ptr<!cir.ptr<!rec_ArrayDtor>> +// CIR: cir.do { +// CIR: %[[CUR:.*]] = cir.load %[[CUR_ADDR]] : !cir.ptr<!cir.ptr<!rec_ArrayDtor>>, !cir.ptr<!rec_ArrayDtor> +// CIR: cir.call @_ZN9ArrayDtorD1Ev(%[[CUR]]) nothrow : (!cir.ptr<!rec_ArrayDtor>) -> () +// CIR: %[[NEG_ONE:.*]] = cir.const #cir.int<-1> : !s64i +// CIR: %[[NEXT:.*]] = cir.ptr_stride %[[CUR]], %[[NEG_ONE]] : (!cir.ptr<!rec_ArrayDtor>, !s64i) -> !cir.ptr<!rec_ArrayDtor> +// CIR: cir.store %[[NEXT]], %[[CUR_ADDR]] : !cir.ptr<!rec_ArrayDtor>, !cir.ptr<!cir.ptr<!rec_ArrayDtor>> +// CIR: cir.yield +// CIR: } while { +// CIR: %[[CUR:.*]] = cir.load %[[CUR_ADDR]] : !cir.ptr<!cir.ptr<!rec_ArrayDtor>>, !cir.ptr<!rec_ArrayDtor> +// CIR: %[[CMP:.*]] = cir.cmp(ne, %[[CUR]], %[[BEGIN]]) : !cir.ptr<!rec_ArrayDtor>, !cir.bool +// CIR: cir.condition(%[[CMP]]) +// CIR: } +// CIR: cir.return +// CIR: } +// +// CIR: cir.func internal private @__cxx_global_var_init() { +// CIR: %[[ARR:.*]] = cir.get_global @arrDtor : !cir.ptr<!cir.array<!rec_ArrayDtor x 16>> +// CIR: %[[DTOR:.*]] = cir.get_global @__cxx_global_array_dtor : !cir.ptr<!cir.func<(!cir.ptr<!void>)>> +// CIR: %[[DTOR_CAST:.*]] = cir.cast bitcast %[[DTOR]] : !cir.ptr<!cir.func<(!cir.ptr<!void>)>> -> !cir.ptr<!cir.func<(!cir.ptr<!void>)>> +// CIR: %[[ARR_CAST:.*]] = cir.cast bitcast %[[ARR]] : !cir.ptr<!cir.array<!rec_ArrayDtor x 16>> -> !cir.ptr<!void> +// CIR: %[[HANDLE:.*]] = cir.get_global @__dso_handle : !cir.ptr<i8> +// CIR: cir.call @__cxa_atexit(%[[DTOR_CAST]], %[[ARR_CAST]], %[[HANDLE]]) : (!cir.ptr<!cir.func<(!cir.ptr<!void>)>>, !cir.ptr<!void>, !cir.ptr<i8>) -> () + +// LLVM: define internal void @__cxx_global_array_dtor(ptr %[[ARR_ARG:.*]]) { +// LLVM: %[[BEGIN:.*]] = getelementptr %struct.ArrayDtor, ptr %[[ARR_ARG]], i32 0 +// LLVM: %[[END:.*]] = getelementptr %struct.ArrayDtor, ptr %[[BEGIN]], i64 15 +// LLVM: %[[CUR_ADDR:.*]] = alloca ptr +// LLVM: store ptr %[[END]], ptr %[[CUR_ADDR]] +// LLVM: br label %[[LOOP_BODY:.*]] +// LLVM: [[LOOP_COND:.*]]: +// LLVM: %[[CUR:.*]] = load ptr, ptr %[[CUR_ADDR]] +// LLVM: %[[CMP:.*]] = icmp ne ptr %[[CUR]], %[[BEGIN]] +// LLVM: br i1 %[[CMP]], label %[[LOOP_BODY]], label %[[LOOP_END:.*]] +// LLVM: [[LOOP_BODY]]: +// LLVM: %[[CUR:.*]] = load ptr, ptr %[[CUR_ADDR]] +// LLVM: call void @_ZN9ArrayDtorD1Ev(ptr %[[CUR]]) #0 +// LLVM: %[[PREV:.*]] = getelementptr %struct.ArrayDtor, ptr %[[CUR]], i64 -1 +// LLVM: store ptr %[[PREV]], ptr %[[CUR_ADDR]] +// LLVM: br label %[[LOOP_COND]] +// LLVM: [[LOOP_END]]: +// LLVM: ret void +// LLVM: } +// +// LLVM: define internal void @__cxx_global_var_init() { +// LLVM: call void @__cxa_atexit(ptr @__cxx_global_array_dtor, ptr @arrDtor, ptr @__dso_handle) + +// Note: OGCG defines these functions in reverse order of CIR->LLVM. +// Note also: OGCG doesn't pass the address of the array to the destructor function. +// Instead, it uses the global directly in the helper function. + +// OGCG: define internal void @__cxx_global_var_init() {{.*}} section ".text.startup" { +// OGCG: call i32 @__cxa_atexit(ptr @__cxx_global_array_dtor, ptr null, ptr @__dso_handle) + +// OGCG: define internal void @__cxx_global_array_dtor(ptr noundef %[[ARG:.*]]) {{.*}} section ".text.startup" { +// OGCG: entry: +// OGCG: %[[UNUSED_ADDR:.*]] = alloca ptr +// OGCG: store ptr %[[ARG]], ptr %[[UNUSED_ADDR]] +// OGCG: br label %[[LOOP_BODY:.*]] +// OGCG: [[LOOP_BODY]]: +// OGCG: %[[PREV:.*]] = phi ptr [ getelementptr inbounds (%struct.ArrayDtor, ptr @arrDtor, i64 16), %entry ], [ %[[CUR:.*]], %[[LOOP_BODY]] ] +// OGCG: %[[CUR]] = getelementptr inbounds %struct.ArrayDtor, ptr %[[PREV]], i64 -1 +// OGCG: call void @_ZN9ArrayDtorD1Ev(ptr noundef nonnull align 1 dereferenceable(1) %[[CUR]]) +// OGCG: %[[DONE:.*]] = icmp eq ptr %[[CUR]], @arrDtor +// OGCG: br i1 %[[DONE]], label %[[LOOP_END:.*]], label %[[LOOP_BODY]] +// OGCG: [[LOOP_END]]: +// OGCG: ret void +// OGCG: } + +// Common init function for all globals with default priority + +// CIR: cir.func private @_GLOBAL__sub_I_[[FILENAME:.*]]() { +// CIR: cir.call @__cxx_global_var_init() : () -> () + +// LLVM: define void @_GLOBAL__sub_I_[[FILENAME:.*]]() +// LLVM: call void @__cxx_global_var_init() + +// OGCG: define internal void @_GLOBAL__sub_I_[[FILENAME:.*]]() {{.*}} section ".text.startup" { +// OGCG: call void @__cxx_global_var_init() _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
