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| author | David Majnemer <david.majnemer@gmail.com> | 2015-11-02 09:01:44 +0000 |
|---|---|---|
| committer | David Majnemer <david.majnemer@gmail.com> | 2015-11-02 09:01:44 +0000 |
| commit | d010d9ad7e2eb77083e433a2070993f5cc28b555 (patch) | |
| tree | 73cc6ddd10414cbfb1dc56379af1b070e286cc2e /test/CodeGenCXX/microsoft-abi-virtual-inheritance.cpp | |
| parent | 49747fe0fe3344f5e9010fd0d269af9d17e32f28 (diff) | |
[MS ABI] Don't zero-initialize vbptrs in bases
Certain CXXConstructExpr nodes require zero-initialization before a
constructor is called. We had a bug in the case where the constructor
is called on a virtual base: we zero-initialized the base's vbptr field.
A complementary bug is present in MSVC where no zero-initialization
occurs for the subobject at all.
This fixes PR25370.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@251783 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/CodeGenCXX/microsoft-abi-virtual-inheritance.cpp')
| -rw-r--r-- | test/CodeGenCXX/microsoft-abi-virtual-inheritance.cpp | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/test/CodeGenCXX/microsoft-abi-virtual-inheritance.cpp b/test/CodeGenCXX/microsoft-abi-virtual-inheritance.cpp index 9a0b011783..8897a38443 100644 --- a/test/CodeGenCXX/microsoft-abi-virtual-inheritance.cpp +++ b/test/CodeGenCXX/microsoft-abi-virtual-inheritance.cpp @@ -455,3 +455,29 @@ void destroy(E *obj) { } } + +namespace test5 { +// PR25370: Don't zero-initialize vbptrs in virtual bases. +struct A { + virtual void f(); +}; + +struct B : virtual A { + int Field; +}; + +struct C : B { + C(); +}; + +C::C() : B() {} +// CHECK-LABEL: define x86_thiscallcc %"struct.test5::C"* @"\01??0C@test5@@QAE@XZ"( +// CHECK: %[[THIS:.*]] = load %"struct.test5::C"*, %"struct.test5::C"** +// CHECK: br i1 %{{.*}}, label %[[INIT_VBASES:.*]], label %[[SKIP_VBASES:.*]] + +// CHECK: %[[SKIP_VBASES]] +// CHECK: %[[B:.*]] = bitcast %"struct.test5::C"* %[[THIS]] to %"struct.test5::B"* +// CHECK: %[[B_i8:.*]] = bitcast %"struct.test5::B"* %[[B]] to i8* +// CHECK: %[[FIELD:.*]] = getelementptr inbounds i8, i8* %[[B_i8]], i32 4 +// CHECK: call void @llvm.memset.p0i8.i32(i8* %[[FIELD]], i8 0, i32 4, i32 4, i1 false) +} |