Author: marshall Date: Wed Feb 7 13:30:17 2018 New Revision: 324531 URL: http://llvm.org/viewvc/llvm-project?rev=324531&view=rev Log: Fix PR#31454 - 'basic_string<T>::push_back() crashes if sizeof(T)>sizeof(long long)'. We were mishandling the small-string optimization calculations for very large 'characters'. This may be an ABI change (change the size of) strings of very large 'characters', but since they never worked, I'm not too concerned.
Modified: libcxx/trunk/include/string libcxx/trunk/test/std/strings/basic.string/string.modifiers/string_append/push_back.pass.cpp Modified: libcxx/trunk/include/string URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/string?rev=324531&r1=324530&r2=324531&view=diff ============================================================================== --- libcxx/trunk/include/string (original) +++ libcxx/trunk/include/string Wed Feb 7 13:30:17 2018 @@ -1363,9 +1363,13 @@ private: enum {__alignment = 16}; static _LIBCPP_INLINE_VISIBILITY size_type __recommend(size_type __s) _NOEXCEPT - {return (__s < __min_cap ? static_cast<size_type>(__min_cap) : - __align_it<sizeof(value_type) < __alignment ? - __alignment/sizeof(value_type) : 1 > (__s+1)) - 1;} + { + if (__s < __min_cap) return static_cast<size_type>(__min_cap) - 1; + size_type __guess = __align_it<sizeof(value_type) < __alignment ? + __alignment/sizeof(value_type) : 1 > (__s+1) - 1; + if (__guess == __min_cap) ++__guess; + return __guess; + } inline void __init(const value_type* __s, size_type __sz, size_type __reserve); Modified: libcxx/trunk/test/std/strings/basic.string/string.modifiers/string_append/push_back.pass.cpp URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/strings/basic.string/string.modifiers/string_append/push_back.pass.cpp?rev=324531&r1=324530&r2=324531&view=diff ============================================================================== --- libcxx/trunk/test/std/strings/basic.string/string.modifiers/string_append/push_back.pass.cpp (original) +++ libcxx/trunk/test/std/strings/basic.string/string.modifiers/string_append/push_back.pass.cpp Wed Feb 7 13:30:17 2018 @@ -48,7 +48,7 @@ int main() test(S("12345678901234567890"), 'a', S("12345678901234567890a")); } #endif -#if 0 + { // https://bugs.llvm.org/show_bug.cgi?id=31454 std::basic_string<veryLarge> s; @@ -57,5 +57,4 @@ int main() s.push_back(vl); s.push_back(vl); } -#endif } _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits