diff options
| -rw-r--r-- | clang/lib/CodeGen/TargetInfo.cpp | 8 | ||||
| -rw-r--r-- | clang/test/CodeGen/arm-vaarg.c | 23 |
2 files changed, 27 insertions, 4 deletions
diff --git a/clang/lib/CodeGen/TargetInfo.cpp b/clang/lib/CodeGen/TargetInfo.cpp index 36e10e4df4c1..44743fa0206f 100644 --- a/clang/lib/CodeGen/TargetInfo.cpp +++ b/clang/lib/CodeGen/TargetInfo.cpp @@ -7047,10 +7047,10 @@ Address ARMABIInfo::EmitVAArg(CodeGenFunction &CGF, Address VAListAddr, // Empty records are ignored for parameter passing purposes. if (isEmptyRecord(getContext(), Ty, true)) { - Address Addr = Address(CGF.Builder.CreateLoad(VAListAddr), - getVAListElementType(CGF), SlotSize); - Addr = CGF.Builder.CreateElementBitCast(Addr, CGF.ConvertTypeForMem(Ty)); - return Addr; + VAListAddr = CGF.Builder.CreateElementBitCast(VAListAddr, CGF.Int8PtrTy); + auto *Load = CGF.Builder.CreateLoad(VAListAddr); + Address Addr = Address(Load, CGF.Int8Ty, SlotSize); + return CGF.Builder.CreateElementBitCast(Addr, CGF.ConvertTypeForMem(Ty)); } CharUnits TySize = getContext().getTypeSizeInChars(Ty); diff --git a/clang/test/CodeGen/arm-vaarg.c b/clang/test/CodeGen/arm-vaarg.c new file mode 100644 index 000000000000..4dab397a20de --- /dev/null +++ b/clang/test/CodeGen/arm-vaarg.c @@ -0,0 +1,23 @@ +// RUN: %clang -Xclang -no-opaque-pointers -mfloat-abi=soft -target arm-linux-gnu -emit-llvm -S -o - %s | FileCheck %s + +struct Empty {}; + +struct Empty emptyvar; + +void take_args(int a, ...) { +// CHECK: [[ALLOCA_VA_LIST:%[a-zA-Z0-9._]+]] = alloca %struct.__va_list, align 4 +// CHECK: call void @llvm.va_start +// CHECK-NEXT: [[AP_ADDR:%[a-zA-Z0-9._]+]] = bitcast %struct.__va_list* [[ALLOCA_VA_LIST]] to i8** +// CHECK-NEXT: [[LOAD_AP:%[a-zA-Z0-9._]+]] = load i8*, i8** [[AP_ADDR]], align 4 +// CHECK-NEXT: [[EMPTY_PTR:%[a-zA-Z0-9._]+]] = bitcast i8* [[LOAD_AP]] to %struct.Empty* + + // It's conceivable that EMPTY_PTR may not actually be a valid pointer + // (e.g. it's at the very bottom of the stack and the next page is + // invalid). This doesn't matter provided it's never loaded (there's no + // well-defined way to tell), but it becomes a problem if we do try to use it. +// CHECK-NOT: load %struct.Empty, %struct.Empty* [[EMPTY_PTR]] + __builtin_va_list l; + __builtin_va_start(l, a); + emptyvar = __builtin_va_arg(l, struct Empty); + __builtin_va_end(l); +} |