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From: "junchao.zhang at gmail dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug c++/107535] New: Shouldn't -fvisibility=hidden hide C++17 inline static variables? Date: Sat, 05 Nov 2022 12:38:34 +0000 [thread overview] Message-ID: <bug-107535-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107535 Bug ID: 107535 Summary: Shouldn't -fvisibility=hidden hide C++17 inline static variables? Product: gcc Version: 11.3.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: junchao.zhang at gmail dot com Target Milestone: --- I think inline static variables are global. However, they could be hidden by -fvisibility=hidden. This is dangerous, since with C++17 inline static variables, they will appear in headers and be included in *.cpp files. If the *.cpp files are compiled with -fvisibility=hidden, each will get their own storage. $ cat foo.hpp struct Foo {static inline int s = 100; }; extern __attribute__ ((visibility ("default"))) void DumpLibFoo(); $ cat foo.cpp #include <stdio.h> #include <foo.hpp> void DumpLibFoo() { printf("In libfoo, Foo::s (%p) = %d\n", &Foo::s, Foo::s); } $ cat test.cpp #include <stdio.h> #include <foo.hpp> int main() { Foo::s = 200; printf("In main, Foo::s (%p) = %d\n", &Foo::s, Foo::s); DumpLibFoo(); return 0; } ----- gcc -std=c++17 -c -fPIC -I./ test.cpp -fvisibility=hidden gcc -std=c++17 -c -fPIC -I./ foo.cpp gcc -o libfoo.so -shared foo.o gcc -std=c++17 -o test test.o -Wl,-rpath ./ -L ./ -lfoo ./test In main, Foo::s (0x5604c2741010) = 200 In libfoo, Foo::s (0x7f4e5173d028) = 100
next reply other threads:[~2022-11-05 12:38 UTC|newest] Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-11-05 12:38 junchao.zhang at gmail dot com [this message] 2022-11-07 7:00 ` [Bug c++/107535] -fvisibility=hidden should not hide C++17 inline static variables rguenth at gcc dot gnu.org 2023-06-15 11:07 ` redi at gcc dot gnu.org
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