Author: hstk30-hw Date: 2024-03-21T09:25:24+08:00 New Revision: 631248dcd26fdec772cedb569be94ff8f12d0901
URL: https://github.com/llvm/llvm-project/commit/631248dcd26fdec772cedb569be94ff8f12d0901 DIFF: https://github.com/llvm/llvm-project/commit/631248dcd26fdec772cedb569be94ff8f12d0901.diff LOG: [X86_64] fix empty structure vaarg in c++ (#77907) SizeInBytes of empty structure is 0 in C, while 1 in C++. And empty structure argument of the function is ignored in X86_64 backend.As a result, the value of variable arguments in C++ is incorrect. fix #77036 Co-authored-by: Longsheng Mou <moulongsh...@huawei.com> Added: clang/test/CodeGenCXX/x86_64-vaarg.cpp Modified: clang/lib/CodeGen/Targets/X86.cpp Removed: ################################################################################ diff --git a/clang/lib/CodeGen/Targets/X86.cpp b/clang/lib/CodeGen/Targets/X86.cpp index 2291c991fb1107..1ec0f159ebcb8a 100644 --- a/clang/lib/CodeGen/Targets/X86.cpp +++ b/clang/lib/CodeGen/Targets/X86.cpp @@ -3019,6 +3019,10 @@ Address X86_64ABIInfo::EmitVAArg(CodeGenFunction &CGF, Address VAListAddr, ABIArgInfo AI = classifyArgumentType(Ty, 0, neededInt, neededSSE, /*isNamedArg*/false); + // Empty records are ignored for parameter passing purposes. + if (AI.isIgnore()) + return CGF.CreateMemTemp(Ty); + // AMD64-ABI 3.5.7p5: Step 1. Determine whether type may be passed // in the registers. If not go to step 7. if (!neededInt && !neededSSE) diff --git a/clang/test/CodeGenCXX/x86_64-vaarg.cpp b/clang/test/CodeGenCXX/x86_64-vaarg.cpp new file mode 100644 index 00000000000000..f0177906a09a81 --- /dev/null +++ b/clang/test/CodeGenCXX/x86_64-vaarg.cpp @@ -0,0 +1,23 @@ +// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py +// RUN: %clang_cc1 -triple x86_64-linux-gnu -emit-llvm -o - %s | FileCheck %s +// RUN: %clang_cc1 -triple x86_64-linux-gnu -emit-llvm -x c -o - %s | FileCheck %s + +typedef struct { struct {} a; } empty; + +// CHECK-LABEL: @{{.*}}empty_record_test +// CHECK-NEXT: entry: +// CHECK-NEXT: [[RETVAL:%.*]] = alloca [[STRUCT_EMPTY:%.*]], align 1 +// CHECK-NEXT: [[Z_ADDR:%.*]] = alloca i32, align 4 +// CHECK-NEXT: [[LIST:%.*]] = alloca [1 x %struct.__va_list_tag], align 16 +// CHECK-NEXT: [[TMP:%.*]] = alloca [[STRUCT_EMPTY]], align 1 +// CHECK-NEXT: store i32 [[Z:%.*]], ptr [[Z_ADDR]], align 4 +// CHECK-NEXT: [[ARRAYDECAY:%.*]] = getelementptr inbounds [1 x %struct.__va_list_tag], ptr [[LIST]], i64 0, i64 0 +// CHECK-NEXT: call void @llvm.va_start(ptr [[ARRAYDECAY]]) +// CHECK-NEXT: [[ARRAYDECAY1:%.*]] = getelementptr inbounds [1 x %struct.__va_list_tag], ptr [[LIST]], i64 0, i64 0 +// CHECK-NEXT: call void @llvm.memcpy.p0.p0.i64(ptr align 1 [[RETVAL]], ptr align 1 [[TMP]], i64 {{.*}}, i1 false) +// CHECK-NEXT: ret void +empty empty_record_test(int z, ...) { + __builtin_va_list list; + __builtin_va_start(list, z); + return __builtin_va_arg(list, empty); +} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
