6a6376b17c
C++11 requires const objects to have a user-provided constructor, even for classes without any fields. DR 253 relaxes this to say "If the implicit default constructor initializes all subobjects, no initializer should be required." clang is currently the only compiler that implements this C++11 rule, and e.g. libstdc++ relies on something like DR 253 to compile in newer versions. This change makes it possible to build code that says `const vector<int> v;' again when using libstdc++5.2 and _GLIBCXX_DEBUG (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60284). Fixes PR23381. http://reviews.llvm.org/D16552 llvm-svn: 261297
53 lines
2.1 KiB
C++
53 lines
2.1 KiB
C++
// RUN: %clang_cc1 -fms-compatibility -fms-extensions -fsyntax-only -verify -std=c++11 %s
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// MSVC produces similar diagnostics.
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__declspec(selectany) void foo() { } // expected-error{{'selectany' can only be applied to data items with external linkage}}
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__declspec(selectany) int x1 = 1;
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const __declspec(selectany) int x2 = 2; // expected-error{{'selectany' can only be applied to data items with external linkage}}
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extern const __declspec(selectany) int x3 = 3;
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extern const int x4;
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const __declspec(selectany) int x4 = 4;
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// MSDN says this is incorrect, but MSVC doesn't diagnose it.
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extern __declspec(selectany) int x5;
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static __declspec(selectany) int x6 = 2; // expected-error{{'selectany' can only be applied to data items with external linkage}}
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// FIXME: MSVC accepts this and makes x7 externally visible and comdat, but keep
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// it as internal and not weak/linkonce.
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static int x7; // expected-note{{previous definition}}
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extern __declspec(selectany) int x7; // expected-warning{{attribute declaration must precede definition}}
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int asdf() { return x7; }
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class X {
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public:
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X(int i) { i++; };
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int i;
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};
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__declspec(selectany) X x(1);
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namespace { class Internal {}; }
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__declspec(selectany) auto x8 = Internal(); // expected-error {{'selectany' can only be applied to data items with external linkage}}
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// The D3D11 headers do something like this. MSVC doesn't error on this at
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// all, even without the __declspec(selectany), in violation of the standard.
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// We fall back to a warning for selectany to accept headers.
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struct SomeStruct {
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int foo;
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};
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extern const __declspec(selectany) SomeStruct some_struct; // expected-warning {{default initialization of an object of const type 'const SomeStruct' without a user-provided default constructor is a Microsoft extension}}
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// It should be possible to redeclare variables that were defined
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// __declspec(selectany) previously.
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extern const SomeStruct some_struct;
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// Without selectany, this should stay an error.
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const SomeStruct some_struct2; // expected-error {{default initialization of an object of const type 'const SomeStruct' without a user-provided default constructor}}
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