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
2.5 KiB
C++
56 lines
2.5 KiB
C++
// Cross comdat example
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// Child VTable is in a comdat section.
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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-DAG: $_ZN1B3fooEv.stub = comdat any
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// CHECK-DAG: $_ZN1A3fooEv.stub = comdat any
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// A comdat is emitted for B but not A
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// CHECK-DAG: $_ZTV1B = comdat any
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// CHECK-DAG: $_ZTS1B = comdat any
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// CHECK-DAG: $_ZTI1B = comdat any
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// CHECK-DAG: $_ZTI1B.rtti_proxy = comdat any
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// CHECK-DAG: $_ZTI1A.rtti_proxy = comdat any
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// VTable for B is emitted here since we access it when creating an instance of B. The VTable is also linkonce_odr and in its own comdat.
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// CHECK-DAG: @_ZTV1B.local = linkonce_odr hidden unnamed_addr constant { [3 x i32] } { [3 x i32] [i32 0, i32 trunc (i64 sub (i64 ptrtoint ({ i8*, i8*, i8* }** @_ZTI1B.rtti_proxy to i64), i64 ptrtoint (i32* getelementptr inbounds ({ [3 x i32] }, { [3 x i32] }* @_ZTV1B.local, i32 0, i32 0, i32 2) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (void (%class.B*)* @_ZN1B3fooEv.stub to i64), i64 ptrtoint (i32* getelementptr inbounds ({ [3 x i32] }, { [3 x i32] }* @_ZTV1B.local, i32 0, i32 0, i32 2) to i64)) to i32)] }, comdat($_ZTV1B), align 4
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// The RTTI objects aren’t that important, but it is good to know that they are emitted here since they are used in the vtable for B, and external references are used for RTTI stuff from A.
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// CHECK-DAG: @_ZTVN10__cxxabiv120__si_class_type_infoE = external global i8*
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// CHECK-DAG: @_ZTS1B =
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// CHECK-DAG: @_ZTI1A =
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// CHECK-DAG: @_ZTI1B =
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// CHECK-DAG: @_ZTI1B.rtti_proxy = hidden unnamed_addr constant { i8*, i8*, i8* }* @_ZTI1B, comdat
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// We will emit a vtable for B here, so it does have an alias, but we will not
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// emit one for A.
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// CHECK: @_ZTV1B = linkonce_odr unnamed_addr alias { [3 x i32] }, { [3 x i32] }* @_ZTV1B.local
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// CHECK-NOT: @_ZTV1A = {{.*}}alias
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// CHECK: define hidden void @_ZN1B3fooEv.stub(%class.B* {{.*}}%0) unnamed_addr #{{[0-9]+}} comdat
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// CHECK: declare void @_ZN1A3fooEv(%class.A*) unnamed_addr
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// CHECK: define hidden void @_ZN1A3fooEv.stub(%class.A* %0) unnamed_addr #{{[0-9]+}} comdat
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// CHECK-NEXT: entry:
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// CHECK-NEXT: tail call void @_ZN1A3fooEv(%class.A* %0)
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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 : public A {
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public:
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inline void foo() override {}
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};
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void A_foo(A *a);
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// func() is used so that the vtable for B is accessed when creating the instance.
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void func() {
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B b;
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A_foo(&b);
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}
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