cf8ff75bad
Thanks to D77248, we can bypass the use of stubs altogether and use PLT relocations if they are available for the target. LLVM and LLD support the R_AARCH64_PLT32 relocation, so we can also guarantee a static PLT relocation on AArch64. Not emitting these stubs saves a lot of extra binary size. Differential Revision: https://reviews.llvm.org/D83812
50 lines
2.7 KiB
C++
50 lines
2.7 KiB
C++
// Cross comdat example
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// Both the parent and child VTablea are in their own comdat sections.
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// RUN: %clang_cc1 %s -triple=aarch64 -S -o - -emit-llvm -fexperimental-relative-c++-abi-vtables | FileCheck %s
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// RUN: %clang_cc1 %s -triple=x86_64 -S -o - -emit-llvm -fexperimental-relative-c++-abi-vtables | FileCheck %s
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// Comdats are emitted for both A and B in this module and for their respective implementations of foo().
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// CHECK: $_ZN1A3fooEv = comdat any
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// CHECK: $_ZN1B3fooEv = comdat any
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// CHECK: $_ZTV1A = comdat any
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// CHECK: $_ZTS1A = comdat any
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// CHECK: $_ZTI1A = comdat any
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// CHECK: $_ZTI1A.rtti_proxy = comdat any
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// CHECK: $_ZTV1B = comdat any
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// CHECK: $_ZTS1B = comdat any
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// CHECK: $_ZTI1B = comdat any
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// CHECK: $_ZTI1B.rtti_proxy = comdat any
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// Both the vtables for A and B are emitted and in their own comdats.
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// CHECK: @_ZTV1A.local = linkonce_odr hidden unnamed_addr constant { [3 x i32] } { [3 x i32] [i32 0, i32 trunc (i64 sub (i64 ptrtoint ({ i8*, i8* }** @_ZTI1A.rtti_proxy to i64), i64 ptrtoint (i32* getelementptr inbounds ({ [3 x i32] }, { [3 x i32] }* @_ZTV1A.local, i32 0, i32 0, i32 2) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (void (%class.A*)* dso_local_equivalent @_ZN1A3fooEv to i64), i64 ptrtoint (i32* getelementptr inbounds ({ [3 x i32] }, { [3 x i32] }* @_ZTV1A.local, i32 0, i32 0, i32 2) to i64)) to i32)] }, comdat($_ZTV1A), align 4
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// CHECK: @_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*)* dso_local_equivalent @_ZN1B3fooEv 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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// CHECK: @_ZTV1A = linkonce_odr unnamed_addr alias { [3 x i32] }, { [3 x i32] }* @_ZTV1A.local
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// CHECK: @_ZTV1B = linkonce_odr unnamed_addr alias { [3 x i32] }, { [3 x i32] }* @_ZTV1B.local
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// CHECK: declare void @_Z5A_fooP1A(%class.A*)
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// The stubs and implementations for foo() are in their own comdat sections.
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// CHECK: define linkonce_odr void @_ZN1A3fooEv(%class.A* {{.*}}%this) unnamed_addr #{{[0-9]+}} comdat
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// CHECK: define linkonce_odr void @_ZN1B3fooEv(%class.B* {{.*}}%this) unnamed_addr #{{[0-9]+}} comdat
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class A {
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public:
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inline 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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A a;
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B b;
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A_foo(&a);
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A_foo(&b);
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}
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