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.
33 lines
1.4 KiB
C++
33 lines
1.4 KiB
C++
/// Check that -fexperimental-omit-vtable-rtti omits the RTTI component from
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/// the vtable.
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// RUN: %clang_cc1 %s -triple=aarch64-unknown-linux-gnu -fno-rtti -fexperimental-omit-vtable-rtti -o - -emit-llvm | FileCheck -check-prefixes=POINTER,RTTI %s
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// RUN: %clang_cc1 %s -triple=aarch64-unknown-linux-gnu -fexperimental-relative-c++-abi-vtables -fno-rtti -fexperimental-omit-vtable-rtti -o - -emit-llvm | FileCheck -check-prefixes=RELATIVE,RTTI %s
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/// Normally, the vtable would contain at least three components:
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/// - An offset to top
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/// - A pointer to the RTTI struct
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/// - A virtual function
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///
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/// Now vtables should have just two components.
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// POINTER: @_ZTV1A = unnamed_addr constant { [2 x ptr] } { [2 x ptr] [ptr null, ptr @_ZN1A3fooEv] }, align 8
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// RELATIVE: @_ZTV1A.local = internal unnamed_addr constant { [2 x i32] } { [2 x i32] [i32 0, i32 trunc (i64 sub (i64 ptrtoint (ptr dso_local_equivalent @_ZN1A3fooEv to i64), i64 ptrtoint (ptr getelementptr inbounds ({ [2 x i32] }, ptr @_ZTV1A.local, i32 0, i32 0, i32 1) to i64)) to i32)] }, align 4
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// RELATIVE: @_ZTV1A = unnamed_addr alias { [2 x i32] }, ptr @_ZTV1A.local
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/// None of these supplementary symbols should be emitted with -fno-rtti, but
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/// as a sanity check lets make sure they're not emitted also.
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// RTTI-NOT: @_ZTVN10__cxxabiv117__class_type_infoE
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// RTTI-NOT: @_ZTS1A
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// RTTI-NOT: @_ZTI1A
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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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void A::foo() {}
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void A_foo(A *a) {
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a->foo();
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}
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