71568a9e28
This patch contains all of the clang changes from D72959. - Generalize the relative vtables ABI such that it can be used by other targets. - Add an enum VTableComponentLayout which controls whether components in the vtable should be pointers to other structs or relative offsets to those structs. Other ABIs can change this enum to restructure how components in the vtable are laid out/accessed. - Add methods to ConstantInitBuilder for inserting relative offsets to a specified position in the aggregate being constructed. - Fix failing tests under new PM and ASan and MSan issues. See D72959 for background info. Differential Revision: https://reviews.llvm.org/D77592
56 lines
3.2 KiB
C++
56 lines
3.2 KiB
C++
// Multiple inheritance.
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// RUN: %clang_cc1 %s -triple=aarch64-unknown-fuchsia -O1 -S -o - -emit-llvm -fexperimental-relative-c++-abi-vtables | FileCheck %s
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// CHECK: %class.C = type { %class.A, %class.B }
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// CHECK: %class.A = type { i32 (...)** }
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// CHECK: %class.B = type { i32 (...)** }
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// VTable for C contains 2 sub-vtables (represented as 2 structs). The first contains the components for B and the second contains the components for C. The RTTI ptr in both arrays still point to the RTTI struct for C.
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// The component for bar() instead points to a thunk which redirects to C::bar() which overrides B::bar().
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// Now that we have a class with 2 parents, the offset to top in the second array is non-zero.
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// CHECK: @_ZTV1C.local = private unnamed_addr constant { [4 x i32], [3 x i32] } { [4 x i32] [i32 0, i32 trunc (i64 sub (i64 ptrtoint ({ i8*, i8*, i32, i32, i8*, i64, i8*, i64 }** @_ZTI1C.rtti_proxy to i64), i64 ptrtoint (i32* getelementptr inbounds ({ [4 x i32], [3 x i32] }, { [4 x i32], [3 x i32] }* @_ZTV1C.local, i32 0, i32 0, i32 2) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (void (%class.C*)* @_ZN1C3fooEv.stub to i64), i64 ptrtoint (i32* getelementptr inbounds ({ [4 x i32], [3 x i32] }, { [4 x i32], [3 x i32] }* @_ZTV1C.local, i32 0, i32 0, i32 2) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (void (%class.C*)* @_ZN1C3barEv.stub to i64), i64 ptrtoint (i32* getelementptr inbounds ({ [4 x i32], [3 x i32] }, { [4 x i32], [3 x i32] }* @_ZTV1C.local, i32 0, i32 0, i32 2) to i64)) to i32)], [3 x i32] [i32 -8, i32 trunc (i64 sub (i64 ptrtoint ({ i8*, i8*, i32, i32, i8*, i64, i8*, i64 }** @_ZTI1C.rtti_proxy to i64), i64 ptrtoint (i32* getelementptr inbounds ({ [4 x i32], [3 x i32] }, { [4 x i32], [3 x i32] }* @_ZTV1C.local, i32 0, i32 1, i32 2) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (void (%class.C*)* @_ZThn8_N1C3barEv.stub to i64), i64 ptrtoint (i32* getelementptr inbounds ({ [4 x i32], [3 x i32] }, { [4 x i32], [3 x i32] }* @_ZTV1C.local, i32 0, i32 1, i32 2) to i64)) to i32)] }, align 4
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// CHECK: @_ZTV1C = unnamed_addr alias { [4 x i32], [3 x i32] }, { [4 x i32], [3 x i32] }* @_ZTV1C.local
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// CHECK: define void @_Z8C_foobarP1C(%class.C* %c) local_unnamed_addr
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// CHECK-NEXT: entry:
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// CHECK-NEXT: [[c:%[0-9]+]] = bitcast %class.C* %c to i8**
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// CHECK-NEXT: [[vtable:%[a-z0-9]+]] = load i8*, i8** [[c]], align 8
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// Offset 0 to get first method
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// CHECK-NEXT: [[ptr1:%[0-9]+]] = call i8* @llvm.load.relative.i32(i8* [[vtable]], i32 0)
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// CHECK-NEXT: [[method1:%[0-9]+]] = bitcast i8* [[ptr1]] to void (%class.C*)*
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// CHECK-NEXT: call void [[method1]](%class.C* %c)
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// CHECK-NEXT: [[vtable:%[a-z0-9]+]] = load i8*, i8** [[c]], align 8
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// Offset by 4 to get the next bar()
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// CHECK-NEXT: [[ptr2:%[0-9]+]] = call i8* @llvm.load.relative.i32(i8* [[vtable]], i32 4)
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// CHECK-NEXT: [[method2:%[0-9]+]] = bitcast i8* [[ptr2]] to void (%class.C*)*
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// CHECK-NEXT: call void [[method2]](%class.C* %c)
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// CHECK-NEXT: ret void
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// CHECK-NEXT: }
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class A {
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public:
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virtual void foo();
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};
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class B {
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virtual void bar();
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};
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class C : public A, public B {
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public:
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void foo() override;
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void bar() override;
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};
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void C::foo() {}
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void C::bar() {}
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void C_foobar(C *c) {
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c->foo();
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c->bar();
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}
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