r369042 - [WebAssembly] Correctly handle va_arg of zero-sized structures
Guanzhong Chen via cfe-commits
cfe-commits at lists.llvm.org
Thu Aug 15 12:33:36 PDT 2019
Author: quantum
Date: Thu Aug 15 12:33:36 2019
New Revision: 369042
URL: http://llvm.org/viewvc/llvm-project?rev=369042&view=rev
Log:
[WebAssembly] Correctly handle va_arg of zero-sized structures
Summary:
D66168 passes size 0 structs indirectly, while the wasm backend expects it to
be passed directly. This causes subsequent variadic arguments to be read
incorrectly.
This diff changes it so that size 0 structs are passed directly.
Reviewers: dschuff, tlively, sbc100
Reviewed By: dschuff
Subscribers: jgravelle-google, aheejin, sunfish, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D66255
Modified:
cfe/trunk/lib/CodeGen/TargetInfo.cpp
cfe/trunk/test/CodeGen/wasm-varargs.c
Modified: cfe/trunk/lib/CodeGen/TargetInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/TargetInfo.cpp?rev=369042&r1=369041&r2=369042&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/TargetInfo.cpp (original)
+++ cfe/trunk/lib/CodeGen/TargetInfo.cpp Thu Aug 15 12:33:36 2019
@@ -833,8 +833,9 @@ ABIArgInfo WebAssemblyABIInfo::classifyR
Address WebAssemblyABIInfo::EmitVAArg(CodeGenFunction &CGF, Address VAListAddr,
QualType Ty) const {
- bool IsIndirect =
- isAggregateTypeForABI(Ty) && !isSingleElementStruct(Ty, getContext());
+ bool IsIndirect = isAggregateTypeForABI(Ty) &&
+ !isEmptyRecord(getContext(), Ty, true) &&
+ !isSingleElementStruct(Ty, getContext());
return emitVoidPtrVAArg(CGF, VAListAddr, Ty, IsIndirect,
getContext().getTypeInfoInChars(Ty),
CharUnits::fromQuantity(4),
Modified: cfe/trunk/test/CodeGen/wasm-varargs.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/wasm-varargs.c?rev=369042&r1=369041&r2=369042&view=diff
==============================================================================
--- cfe/trunk/test/CodeGen/wasm-varargs.c (original)
+++ cfe/trunk/test/CodeGen/wasm-varargs.c Thu Aug 15 12:33:36 2019
@@ -80,21 +80,61 @@ struct S test_struct(char *fmt, ...) {
return v;
}
-// CHECK: define void @test_struct([[STRUCT_S:%[^,=]+]]*{{.*}} noalias sret [[AGG_RESULT:%.*]], i8*{{.*}} %fmt, ...) {{.*}} {
-// CHECK: [[FMT_ADDR:%[^,=]+]] = alloca i8*, align 4
-// CHECK: [[VA:%[^,=]+]] = alloca i8*, align 4
-// CHECK: store i8* %fmt, i8** [[FMT_ADDR]], align 4
-// CHECK: [[VA1:%[^,=]+]] = bitcast i8** [[VA]] to i8*
-// CHECK: call void @llvm.va_start(i8* [[VA1]])
-// CHECK: [[ARGP_CUR:%[^,=]+]] = load i8*, i8** [[VA]], align 4
-// CHECK: [[ARGP_NEXT:%[^,=]+]] = getelementptr inbounds i8, i8* [[ARGP_CUR]], i32 4
-// CHECK: store i8* [[ARGP_NEXT]], i8** [[VA]], align 4
-// CHECK: [[R3:%[^,=]+]] = bitcast i8* [[ARGP_CUR]] to [[STRUCT_S]]**
-// CHECK: [[R4:%[^,=]+]] = load [[STRUCT_S]]*, [[STRUCT_S]]** %0, align 4
-// CHECK: [[R5:%[^,=]+]] = bitcast [[STRUCT_S]]* [[AGG_RESULT]] to i8*
-// CHECK: [[R6:%[^,=]+]] = bitcast [[STRUCT_S]]* [[R4]] to i8*
-// CHECK: call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 4 [[R5]], i8* align 4 [[R6]], i32 12, i1 false)
-// CHECK: [[VA2:%[^,=]+]] = bitcast i8** [[VA]] to i8*
-// CHECK: call void @llvm.va_end(i8* [[VA2]])
-// CHECK: ret void
-// CHECK: }
+// CHECK: define void @test_struct([[STRUCT_S:%[^,=]+]]*{{.*}} noalias sret [[AGG_RESULT:%.*]], i8*{{.*}} %fmt, ...) {{.*}} {
+// CHECK: [[FMT_ADDR:%[^,=]+]] = alloca i8*, align 4
+// CHECK-NEXT: [[VA:%[^,=]+]] = alloca i8*, align 4
+// CHECK-NEXT: store i8* %fmt, i8** [[FMT_ADDR]], align 4
+// CHECK-NEXT: [[VA1:%[^,=]+]] = bitcast i8** [[VA]] to i8*
+// CHECK-NEXT: call void @llvm.va_start(i8* [[VA1]])
+// CHECK-NEXT: [[ARGP_CUR:%[^,=]+]] = load i8*, i8** [[VA]], align 4
+// CHECK-NEXT: [[ARGP_NEXT:%[^,=]+]] = getelementptr inbounds i8, i8* [[ARGP_CUR]], i32 4
+// CHECK-NEXT: store i8* [[ARGP_NEXT]], i8** [[VA]], align 4
+// CHECK-NEXT: [[R3:%[^,=]+]] = bitcast i8* [[ARGP_CUR]] to [[STRUCT_S]]**
+// CHECK-NEXT: [[R4:%[^,=]+]] = load [[STRUCT_S]]*, [[STRUCT_S]]** [[R3]], align 4
+// CHECK-NEXT: [[R5:%[^,=]+]] = bitcast [[STRUCT_S]]* [[AGG_RESULT]] to i8*
+// CHECK-NEXT: [[R6:%[^,=]+]] = bitcast [[STRUCT_S]]* [[R4]] to i8*
+// CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 4 [[R5]], i8* align 4 [[R6]], i32 12, i1 false)
+// CHECK-NEXT: [[VA2:%[^,=]+]] = bitcast i8** [[VA]] to i8*
+// CHECK-NEXT: call void @llvm.va_end(i8* [[VA2]])
+// CHECK-NEXT: ret void
+// CHECK-NEXT: }
+
+struct Z {};
+
+struct S test_empty_struct(char *fmt, ...) {
+ va_list va;
+
+ va_start(va, fmt);
+ struct Z u = va_arg(va, struct Z);
+ struct S v = va_arg(va, struct S);
+ va_end(va);
+
+ return v;
+}
+
+// CHECK: define void @test_empty_struct([[STRUCT_S:%[^,=]+]]*{{.*}} noalias sret [[AGG_RESULT:%.*]], i8*{{.*}} %fmt, ...) {{.*}} {
+// CHECK: [[FMT_ADDR:%[^,=]+]] = alloca i8*, align 4
+// CHECK-NEXT: [[VA:%[^,=]+]] = alloca i8*, align 4
+// CHECK-NEXT: [[U:%[^,=]+]] = alloca [[STRUCT_Z:%[^,=]+]], align 1
+// CHECK-NEXT: store i8* %fmt, i8** [[FMT_ADDR]], align 4
+// CHECK-NEXT: [[VA1:%[^,=]+]] = bitcast i8** [[VA]] to i8*
+// CHECK-NEXT: call void @llvm.va_start(i8* [[VA1]])
+// CHECK-NEXT: [[ARGP_CUR:%[^,=]+]] = load i8*, i8** [[VA]], align 4
+// CHECK-NEXT: [[ARGP_NEXT:%[^,=]+]] = getelementptr inbounds i8, i8* [[ARGP_CUR]], i32 0
+// CHECK-NEXT: store i8* [[ARGP_NEXT]], i8** [[VA]], align 4
+// CHECK-NEXT: [[R0:%[^,=]+]] = bitcast i8* [[ARGP_CUR]] to [[STRUCT_Z]]*
+// CHECK-NEXT: [[R1:%[^,=]+]] = bitcast [[STRUCT_Z]]* [[U]] to i8*
+// CHECK-NEXT: [[R2:%[^,=]+]] = bitcast [[STRUCT_Z]]* [[R0]] to i8*
+// CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 1 [[R1]], i8* align 4 [[R2]], i32 0, i1 false)
+// CHECK-NEXT: [[ARGP_CUR2:%[^,=]+]] = load i8*, i8** [[VA]], align 4
+// CHECK-NEXT: [[ARGP_NEXT2:%[^,=]+]] = getelementptr inbounds i8, i8* [[ARGP_CUR2]], i32 4
+// CHECK-NEXT: store i8* [[ARGP_NEXT2]], i8** [[VA]], align 4
+// CHECK-NEXT: [[R3:%[^,=]+]] = bitcast i8* [[ARGP_CUR2]] to [[STRUCT_S]]**
+// CHECK-NEXT: [[R4:%[^,=]+]] = load [[STRUCT_S]]*, [[STRUCT_S]]** [[R3]], align 4
+// CHECK-NEXT: [[R5:%[^,=]+]] = bitcast [[STRUCT_S]]* [[AGG_RESULT]] to i8*
+// CHECK-NEXT: [[R6:%[^,=]+]] = bitcast [[STRUCT_S]]* [[R4]] to i8*
+// CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 4 [[R5]], i8* align 4 [[R6]], i32 12, i1 false)
+// CHECK-NEXT: [[VA2:%[^,=]+]] = bitcast i8** [[VA]] to i8*
+// CHECK-NEXT: call void @llvm.va_end(i8* [[VA2]])
+// CHECK-NEXT: ret void
+// CHECK-NEXT: }
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