b83f01d005
__pbase_type_info::__do_catch(), used to catch pointer type exceptions, did not check if the type info object to compare against is a pointer type info object before doing a static down-cast to a pointer type info object. If RTTI is disabled, this leads to the following situation: Since a pointer type info object has additional fields, they would end up being undefined if the actual type info object was not a pointer type info object. A simple check has been added before the down-cast happens. Note that a consequence of this check is that exceptions of type pointer-to-member cannot be caught anymore. In case RTTI is enabled, this does not seem to be a problem because RTTI-based checks would run before and prevent running into the bad down-cast. Hence, the fix is disabled if RTTI is enabled and exceptions of type pointer-to-member can still be caught. libstdc++-v3/ChangeLog: PR libstdc++/105387 * libsupc++/pbase_type_info.cc (__do_catch) [!__cpp_rtti]: Add check that the thrown type is actually a pointer. * testsuite/18_support/105387.cc: New test. * testsuite/18_support/105387_memptr.cc: New test. Signed-off-by: Jakob Hasse <jakob.hasse@espressif.com>
63 lines
2.2 KiB
C++
63 lines
2.2 KiB
C++
// { dg-do run }
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#include <stdexcept>
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#include <cxxabi.h>
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#include <testsuite_hooks.h>
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// Test cases for PR libstdc++/105387
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// This test is to trigger undefined behavior if the bug 105387 is present
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// in the code. Note, however, given that the bug is present, this test runs
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// into undefined behavior which can also mean that it passes.
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// It has been observed to fail quite reliably on x86_64-linux-gnu but only
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// fail sporadically on Xtensa, depending on the code placement.
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void portable_test()
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{
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bool exception_thrown = false;
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try {
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throw std::runtime_error("test");
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} catch (const char *e) {
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VERIFY(false);
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} catch (const std::exception &e) {
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exception_thrown = true;
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}
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VERIFY(exception_thrown);
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}
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// This test relies on the types defined in the files typeinfo and cxxabi.h
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// It is therefore less portable then the test case above but should be
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// guaranteed to fail if the implementation has the bug 105387.
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//
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// This test case checks that __pbase_type_info::__do_catch() behaves
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// correctly when called with a non-pointer type info object as argument.
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// In particular, __pbase_type_info::__do_catch() should not cast
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// the given type object into a pointer type and try to access the
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// extended fields.
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void non_portable_test()
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{
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// Create a zero-initialized buffer for allocation of the type object
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unsigned char buffer [sizeof(__cxxabiv1::__fundamental_type_info) * 2] = {};
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// Use placement-new to create the fundamental type info object in the
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// first half of the buffer. Whenever that type info object will be
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// casted to a pointer type info object, the extended fields of the
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// pointer type info object will be in the second half of the buffer
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// and hence be guaranteed zero.
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__cxxabiv1::__fundamental_type_info *p_fund_info
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= new(buffer) __cxxabiv1::__fundamental_type_info("fund_type");
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__cxxabiv1::__pointer_type_info ptr_info("ptr_type", 0, p_fund_info);
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// __do_catch is declared protected in __pointer_type_info, but public in
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// type_info, so we upcast it here
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std::type_info *abstract_ptr_info = static_cast<std::type_info*>(&ptr_info);
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VERIFY(abstract_ptr_info->__do_catch(p_fund_info, 0, 1) == false);
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}
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int main()
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{
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portable_test();
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non_portable_test();
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return 0;
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}
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