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| author | Guanzhong Chen <gzchen@google.com> | 2019-08-13 21:41:11 +0000 |
|---|---|---|
| committer | Guanzhong Chen <gzchen@google.com> | 2019-08-13 21:41:11 +0000 |
| commit | 8a503e439d0d254e5be5c2655a63a5a34b70dbac (patch) | |
| tree | a1bc8ea03459b97817d1eb4d8ba67bcf87c215f4 | |
| parent | 10f0668b572d49c1cda42f60d49a310cff2cd5a6 (diff) | |
| download | bcm5719-llvm-8a503e439d0d254e5be5c2655a63a5a34b70dbac.tar.gz bcm5719-llvm-8a503e439d0d254e5be5c2655a63a5a34b70dbac.zip | |
[WebAssembly] Make clang emit correct va_arg code for structs
Summary:
In the WebAssembly backend, when lowering variadic function calls, non-single
member aggregate type arguments are always passed by pointer.
However, when emitting va_arg code in clang, the arguments are instead read as
if they are passed directly. This results in the pointer being read as the
actual structure.
Fixes https://github.com/emscripten-core/emscripten/issues/9042.
Reviewers: tlively, sbc100, kripken, aheejin, dschuff
Reviewed By: dschuff
Subscribers: dschuff, jgravelle-google, sunfish, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D66168
llvm-svn: 368750
| -rw-r--r-- | clang/lib/CodeGen/TargetInfo.cpp | 6 | ||||
| -rw-r--r-- | clang/test/CodeGen/wasm-varargs.c | 11 |
2 files changed, 10 insertions, 7 deletions
diff --git a/clang/lib/CodeGen/TargetInfo.cpp b/clang/lib/CodeGen/TargetInfo.cpp index 884b80cecd0..d96b5408f31 100644 --- a/clang/lib/CodeGen/TargetInfo.cpp +++ b/clang/lib/CodeGen/TargetInfo.cpp @@ -833,10 +833,12 @@ ABIArgInfo WebAssemblyABIInfo::classifyReturnType(QualType RetTy) const { Address WebAssemblyABIInfo::EmitVAArg(CodeGenFunction &CGF, Address VAListAddr, QualType Ty) const { - return emitVoidPtrVAArg(CGF, VAListAddr, Ty, /*IsIndirect=*/ false, + bool IsIndirect = + isAggregateTypeForABI(Ty) && !isSingleElementStruct(Ty, getContext()); + return emitVoidPtrVAArg(CGF, VAListAddr, Ty, IsIndirect, getContext().getTypeInfoInChars(Ty), CharUnits::fromQuantity(4), - /*AllowHigherAlign=*/ true); + /*AllowHigherAlign=*/true); } //===----------------------------------------------------------------------===// diff --git a/clang/test/CodeGen/wasm-varargs.c b/clang/test/CodeGen/wasm-varargs.c index 4cb46f1c190..fa672064d0f 100644 --- a/clang/test/CodeGen/wasm-varargs.c +++ b/clang/test/CodeGen/wasm-varargs.c @@ -87,12 +87,13 @@ struct S test_struct(char *fmt, ...) { // 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 12 +// 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:%[^,=]+]] = bitcast [[STRUCT_S]]* [[AGG_RESULT]] to i8* -// CHECK: [[R5:%[^,=]+]] = bitcast [[STRUCT_S]]* [[R3]] to i8* -// CHECK: call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 4 [[R4]], i8* align 4 [[R5]], i32 12, i1 false) +// 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 |
