0371dff995
When using the relative vtable ABI, if a vtable is not dso_local, it's given private linkage (if not COMDAT) or hidden visibility (if COMDAT) to make it dso_local (to place it in rodata instead of data.rel.ro), and an alias generated with the original linkage and visibility. This alias could later be removed from the symbol table, e.g. if using a version script, at which point we lose all symbol information about the vtable. Use internal linkage instead of private linkage to avoid this. While I'm here, clarify the comment about why COMDAT vtables can't use internal (or private) linkage, and associate it with the else block where hidden visibility is applied instead of internal linkage.
83 lines
9.1 KiB
C++
83 lines
9.1 KiB
C++
// Diamond virtual inheritance.
|
|
// This should cover virtual inheritance, construction vtables, and VTTs.
|
|
|
|
// RUN: %clang_cc1 %s -triple=aarch64-unknown-fuchsia -O1 -o - -emit-llvm -fhalf-no-semantic-interposition | FileCheck %s
|
|
|
|
// Class A contains a vtable ptr, then int, then padding
|
|
|
|
// VTable for B. Contains an extra field at the start for the virtual-base offset.
|
|
// CHECK: @_ZTV1B.local = internal unnamed_addr constant { [4 x i32], [4 x i32] } { [4 x i32] [i32 8, i32 0, i32 trunc (i64 sub (i64 ptrtoint (ptr @_ZTI1B.rtti_proxy to i64), i64 ptrtoint (ptr getelementptr inbounds ({ [4 x i32], [4 x i32] }, ptr @_ZTV1B.local, i32 0, i32 0, i32 3) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (ptr dso_local_equivalent @_ZN1B4barBEv to i64), i64 ptrtoint (ptr getelementptr inbounds ({ [4 x i32], [4 x i32] }, ptr @_ZTV1B.local, i32 0, i32 0, i32 3) to i64)) to i32)], [4 x i32] [i32 0, i32 -8, i32 trunc (i64 sub (i64 ptrtoint (ptr @_ZTI1B.rtti_proxy to i64), i64 ptrtoint (ptr getelementptr inbounds ({ [4 x i32], [4 x i32] }, ptr @_ZTV1B.local, i32 0, i32 1, i32 3) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (ptr dso_local_equivalent @_ZN1A3fooEv to i64), i64 ptrtoint (ptr getelementptr inbounds ({ [4 x i32], [4 x i32] }, ptr @_ZTV1B.local, i32 0, i32 1, i32 3) to i64)) to i32)] }, align 4
|
|
|
|
// VTT for B
|
|
// CHECK: @_ZTT1B ={{.*}} unnamed_addr constant [2 x ptr] [ptr getelementptr inbounds inrange(-12, 4) ({ [4 x i32], [4 x i32] }, ptr @_ZTV1B.local, i32 0, i32 0, i32 3), ptr getelementptr inbounds inrange(-12, 4) ({ [4 x i32], [4 x i32] }, ptr @_ZTV1B.local, i32 0, i32 1, i32 3)], align 8
|
|
|
|
// VTable for C
|
|
// CHECK: @_ZTV1C.local = internal unnamed_addr constant { [4 x i32], [4 x i32] } { [4 x i32] [i32 8, i32 0, i32 trunc (i64 sub (i64 ptrtoint (ptr @_ZTI1C.rtti_proxy to i64), i64 ptrtoint (ptr getelementptr inbounds ({ [4 x i32], [4 x i32] }, ptr @_ZTV1C.local, i32 0, i32 0, i32 3) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (ptr dso_local_equivalent @_ZN1C4barCEv to i64), i64 ptrtoint (ptr getelementptr inbounds ({ [4 x i32], [4 x i32] }, ptr @_ZTV1C.local, i32 0, i32 0, i32 3) to i64)) to i32)], [4 x i32] [i32 0, i32 -8, i32 trunc (i64 sub (i64 ptrtoint (ptr @_ZTI1C.rtti_proxy to i64), i64 ptrtoint (ptr getelementptr inbounds ({ [4 x i32], [4 x i32] }, ptr @_ZTV1C.local, i32 0, i32 1, i32 3) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (ptr dso_local_equivalent @_ZN1A3fooEv to i64), i64 ptrtoint (ptr getelementptr inbounds ({ [4 x i32], [4 x i32] }, ptr @_ZTV1C.local, i32 0, i32 1, i32 3) to i64)) to i32)] }, align 4
|
|
|
|
// VTT for C
|
|
// CHECK: @_ZTT1C ={{.*}} unnamed_addr constant [2 x ptr] [ptr getelementptr inbounds inrange(-12, 4) ({ [4 x i32], [4 x i32] }, ptr @_ZTV1C.local, i32 0, i32 0, i32 3), ptr getelementptr inbounds inrange(-12, 4) ({ [4 x i32], [4 x i32] }, ptr @_ZTV1C.local, i32 0, i32 1, i32 3)], align 8
|
|
|
|
// VTable for D
|
|
// CHECK: @_ZTV1D.local = internal unnamed_addr constant { [5 x i32], [4 x i32], [4 x i32] } { [5 x i32] [i32 16, i32 0, i32 trunc (i64 sub (i64 ptrtoint (ptr @_ZTI1D.rtti_proxy to i64), i64 ptrtoint (ptr getelementptr inbounds ({ [5 x i32], [4 x i32], [4 x i32] }, ptr @_ZTV1D.local, i32 0, i32 0, i32 3) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (ptr dso_local_equivalent @_ZN1B4barBEv to i64), i64 ptrtoint (ptr getelementptr inbounds ({ [5 x i32], [4 x i32], [4 x i32] }, ptr @_ZTV1D.local, i32 0, i32 0, i32 3) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (ptr dso_local_equivalent @_ZN1D3bazEv to i64), i64 ptrtoint (ptr getelementptr inbounds ({ [5 x i32], [4 x i32], [4 x i32] }, ptr @_ZTV1D.local, i32 0, i32 0, i32 3) to i64)) to i32)], [4 x i32] [i32 8, i32 -8, i32 trunc (i64 sub (i64 ptrtoint (ptr @_ZTI1D.rtti_proxy to i64), i64 ptrtoint (ptr getelementptr inbounds ({ [5 x i32], [4 x i32], [4 x i32] }, ptr @_ZTV1D.local, i32 0, i32 1, i32 3) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (ptr dso_local_equivalent @_ZN1C4barCEv to i64), i64 ptrtoint (ptr getelementptr inbounds ({ [5 x i32], [4 x i32], [4 x i32] }, ptr @_ZTV1D.local, i32 0, i32 1, i32 3) to i64)) to i32)], [4 x i32] [i32 0, i32 -16, i32 trunc (i64 sub (i64 ptrtoint (ptr @_ZTI1D.rtti_proxy to i64), i64 ptrtoint (ptr getelementptr inbounds ({ [5 x i32], [4 x i32], [4 x i32] }, ptr @_ZTV1D.local, i32 0, i32 2, i32 3) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (ptr dso_local_equivalent @_ZN1A3fooEv to i64), i64 ptrtoint (ptr getelementptr inbounds ({ [5 x i32], [4 x i32], [4 x i32] }, ptr @_ZTV1D.local, i32 0, i32 2, i32 3) to i64)) to i32)] }, align 4
|
|
|
|
// VTT for D
|
|
// CHECK: @_ZTT1D ={{.*}} unnamed_addr constant [7 x ptr] [ptr getelementptr inbounds inrange(-12, 8) ({ [5 x i32], [4 x i32], [4 x i32] }, ptr @_ZTV1D.local, i32 0, i32 0, i32 3), ptr getelementptr inbounds inrange(-12, 4) ({ [4 x i32], [4 x i32] }, ptr @_ZTC1D0_1B.local, i32 0, i32 0, i32 3), ptr getelementptr inbounds inrange(-12, 4) ({ [4 x i32], [4 x i32] }, ptr @_ZTC1D0_1B.local, i32 0, i32 1, i32 3), ptr getelementptr inbounds inrange(-12, 4) ({ [4 x i32], [4 x i32] }, ptr @_ZTC1D8_1C.local, i32 0, i32 0, i32 3), ptr getelementptr inbounds inrange(-12, 4) ({ [4 x i32], [4 x i32] }, ptr @_ZTC1D8_1C.local, i32 0, i32 1, i32 3), ptr getelementptr inbounds inrange(-12, 4) ({ [5 x i32], [4 x i32], [4 x i32] }, ptr @_ZTV1D.local, i32 0, i32 2, i32 3), ptr getelementptr inbounds inrange(-12, 4) ({ [5 x i32], [4 x i32], [4 x i32] }, ptr @_ZTV1D.local, i32 0, i32 1, i32 3)], align 8
|
|
|
|
// Construction vtable for B-in-D
|
|
// CHECK: @_ZTC1D0_1B.local = internal unnamed_addr constant { [4 x i32], [4 x i32] } { [4 x i32] [i32 16, i32 0, i32 trunc (i64 sub (i64 ptrtoint (ptr @_ZTI1B.rtti_proxy to i64), i64 ptrtoint (ptr getelementptr inbounds ({ [4 x i32], [4 x i32] }, ptr @_ZTC1D0_1B.local, i32 0, i32 0, i32 3) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (ptr dso_local_equivalent @_ZN1B4barBEv to i64), i64 ptrtoint (ptr getelementptr inbounds ({ [4 x i32], [4 x i32] }, ptr @_ZTC1D0_1B.local, i32 0, i32 0, i32 3) to i64)) to i32)], [4 x i32] [i32 0, i32 -16, i32 trunc (i64 sub (i64 ptrtoint (ptr @_ZTI1B.rtti_proxy to i64), i64 ptrtoint (ptr getelementptr inbounds ({ [4 x i32], [4 x i32] }, ptr @_ZTC1D0_1B.local, i32 0, i32 1, i32 3) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (ptr dso_local_equivalent @_ZN1A3fooEv to i64), i64 ptrtoint (ptr getelementptr inbounds ({ [4 x i32], [4 x i32] }, ptr @_ZTC1D0_1B.local, i32 0, i32 1, i32 3) to i64)) to i32)] }, align 4
|
|
|
|
// Construction vtable for C-in-D
|
|
// CHECK: @_ZTC1D8_1C.local = internal unnamed_addr constant { [4 x i32], [4 x i32] } { [4 x i32] [i32 8, i32 0, i32 trunc (i64 sub (i64 ptrtoint (ptr @_ZTI1C.rtti_proxy to i64), i64 ptrtoint (ptr getelementptr inbounds ({ [4 x i32], [4 x i32] }, ptr @_ZTC1D8_1C.local, i32 0, i32 0, i32 3) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (ptr dso_local_equivalent @_ZN1C4barCEv to i64), i64 ptrtoint (ptr getelementptr inbounds ({ [4 x i32], [4 x i32] }, ptr @_ZTC1D8_1C.local, i32 0, i32 0, i32 3) to i64)) to i32)], [4 x i32] [i32 0, i32 -8, i32 trunc (i64 sub (i64 ptrtoint (ptr @_ZTI1C.rtti_proxy to i64), i64 ptrtoint (ptr getelementptr inbounds ({ [4 x i32], [4 x i32] }, ptr @_ZTC1D8_1C.local, i32 0, i32 1, i32 3) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (ptr dso_local_equivalent @_ZN1A3fooEv to i64), i64 ptrtoint (ptr getelementptr inbounds ({ [4 x i32], [4 x i32] }, ptr @_ZTC1D8_1C.local, i32 0, i32 1, i32 3) to i64)) to i32)] }, align 4
|
|
|
|
// CHECK: @_ZTV1B ={{.*}} unnamed_addr alias { [4 x i32], [4 x i32] }, ptr @_ZTV1B.local
|
|
// CHECK: @_ZTV1C ={{.*}} unnamed_addr alias { [4 x i32], [4 x i32] }, ptr @_ZTV1C.local
|
|
// CHECK: @_ZTC1D0_1B ={{.*}} unnamed_addr alias { [4 x i32], [4 x i32] }, ptr @_ZTC1D0_1B.local
|
|
// CHECK: @_ZTC1D8_1C ={{.*}} unnamed_addr alias { [4 x i32], [4 x i32] }, ptr @_ZTC1D8_1C.local
|
|
// CHECK: @_ZTV1D ={{.*}} unnamed_addr alias { [5 x i32], [4 x i32], [4 x i32] }, ptr @_ZTV1D.local
|
|
|
|
// CHECK: define{{.*}} void @_Z5D_fooP1D(ptr noundef %d) local_unnamed_addr
|
|
// CHECK-NEXT: entry:
|
|
// CHECK-NEXT: [[vtable:%[a-z0-9]+]] = load ptr, ptr %d, align 8
|
|
|
|
// This normally would've been -24 (8 bytes for the virtual call/base offset, 8
|
|
// bytes for the offset to top, and 8 bytes for the RTTI pointer), but since all
|
|
// components in the vtable are halved to 4 bytes, the offset is halved to -12.
|
|
// CHECK-NEXT: [[vbase_offset_ptr:%[a-z0-9.]+]] = getelementptr i8, ptr [[vtable]], i64 -12
|
|
|
|
// CHECK-NEXT: [[vbase_offset:%[a-z0-9.]+]] = load i32, ptr [[vbase_offset_ptr]], align 4
|
|
// CHECK-NEXT: [[vbase_offset2:%.+]] = sext i32 [[vbase_offset]] to i64
|
|
// CHECK-NEXT: [[add_ptr:%[a-z0-9.]+]] = getelementptr inbounds i8, ptr %d, i64 [[vbase_offset2]]
|
|
// CHECK-NEXT: [[vtable:%[a-z0-9]+]] = load ptr, ptr [[add_ptr]], align 8
|
|
// CHECK-NEXT: [[ptr:%[0-9]+]] = tail call ptr @llvm.load.relative.i32(ptr [[vtable]], i32 0)
|
|
// CHECK-NEXT: call void [[ptr]](ptr {{[^,]*}} [[add_ptr]])
|
|
// CHECK-NEXT: ret void
|
|
// CHECK-NEXT: }
|
|
|
|
class A {
|
|
public:
|
|
virtual void foo();
|
|
int a;
|
|
};
|
|
|
|
class B : public virtual A {
|
|
public:
|
|
virtual void barB();
|
|
};
|
|
|
|
class C : public virtual A {
|
|
virtual void barC();
|
|
};
|
|
|
|
class D : public B, C {
|
|
public:
|
|
virtual void baz();
|
|
};
|
|
|
|
void B::barB() {}
|
|
void C::barC() {}
|
|
void D::baz() {}
|
|
|
|
void D_foo(D *d) {
|
|
d->foo();
|
|
}
|