From 36eec25a6fa7c32e36d7f77f85c8acb7ff38a66b Mon Sep 17 00:00:00 2001 From: Jonathan Wakely Date: Fri, 15 Jun 2018 17:47:55 +0100 Subject: [PATCH] Decorate string_view members with nonnull attribute The C++ committee has confirmed that passing a null pointer to the unary basic_string_view constructor is undefined. This removes the check from our implementation, and adds the nonnull attribute to warn when the compiler can detect undefined input. * include/std/string_view (basic_string_view(const CharT*)): Remove check for null pointer and add nonnull attribute. (compare(const CharT*), compare(size_type, size_type, const CharT*)) (find(const CharT*, size_type), rfind(const CharT*, size_type)) (find_first_of(const CharT*, size_type)) (find_last_of(const CharT*, size_type)) (find_first_not_of(const CharT*, size_type)) (find_last_not_of(const CharT*, size_type)): Add nonnull attribute. * testsuite/21_strings/basic_string_view/cons/char/nonnull.cc: New. * testsuite/21_strings/basic_string_view/operations/compare/char/ nonnull.cc: New. * testsuite/21_strings/basic_string_view/operations/find/char/ nonnull.cc: New. * testsuite/21_strings/basic_string_view/operations/rfind/char/ nonnull.cc: New. From-SVN: r261638 --- libstdc++-v3/ChangeLog | 16 +++++++++ libstdc++-v3/include/std/string_view | 24 +++++++------- .../basic_string_view/cons/char/nonnull.cc | 29 ++++++++++++++++ .../basic_string_view/cons/wchar_t/nonnull.cc | 29 ++++++++++++++++ .../operations/compare/char/nonnull.cc | 29 ++++++++++++++++ .../operations/find/char/nonnull.cc | 33 +++++++++++++++++++ .../operations/rfind/char/nonnull.cc | 29 ++++++++++++++++ 7 files changed, 178 insertions(+), 11 deletions(-) create mode 100644 libstdc++-v3/testsuite/21_strings/basic_string_view/cons/char/nonnull.cc create mode 100644 libstdc++-v3/testsuite/21_strings/basic_string_view/cons/wchar_t/nonnull.cc create mode 100644 libstdc++-v3/testsuite/21_strings/basic_string_view/operations/compare/char/nonnull.cc create mode 100644 libstdc++-v3/testsuite/21_strings/basic_string_view/operations/find/char/nonnull.cc create mode 100644 libstdc++-v3/testsuite/21_strings/basic_string_view/operations/rfind/char/nonnull.cc diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index 482f64ee460..b7cef6057b1 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -1,5 +1,21 @@ 2018-06-15 Jonathan Wakely + * include/std/string_view (basic_string_view(const CharT*)): Remove + check for null pointer and add nonnull attribute. + (compare(const CharT*), compare(size_type, size_type, const CharT*)) + (find(const CharT*, size_type), rfind(const CharT*, size_type)) + (find_first_of(const CharT*, size_type)) + (find_last_of(const CharT*, size_type)) + (find_first_not_of(const CharT*, size_type)) + (find_last_not_of(const CharT*, size_type)): Add nonnull attribute. + * testsuite/21_strings/basic_string_view/cons/char/nonnull.cc: New. + * testsuite/21_strings/basic_string_view/operations/compare/char/ + nonnull.cc: New. + * testsuite/21_strings/basic_string_view/operations/find/char/ + nonnull.cc: New. + * testsuite/21_strings/basic_string_view/operations/rfind/char/ + nonnull.cc: New. + PR libstdc++/86168 * include/bits/random.h (random_device(const string&)): Remove default argument. diff --git a/libstdc++-v3/include/std/string_view b/libstdc++-v3/include/std/string_view index 9f39df853e8..f84664ca286 100644 --- a/libstdc++-v3/include/std/string_view +++ b/libstdc++-v3/include/std/string_view @@ -96,8 +96,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION constexpr basic_string_view(const basic_string_view&) noexcept = default; - constexpr basic_string_view(const _CharT* __str) noexcept - : _M_len{__str == nullptr ? 0 : traits_type::length(__str)}, + __attribute__((__nonnull__)) constexpr + basic_string_view(const _CharT* __str) noexcept + : _M_len{traits_type::length(__str)}, _M_str{__str} { } @@ -270,11 +271,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION return this->substr(__pos1, __n1).compare(__str.substr(__pos2, __n2)); } - constexpr int + __attribute__((__nonnull__)) constexpr int compare(const _CharT* __str) const noexcept { return this->compare(basic_string_view{__str}); } - constexpr int + __attribute__((__nonnull__)) constexpr int compare(size_type __pos1, size_type __n1, const _CharT* __str) const { return this->substr(__pos1, __n1).compare(basic_string_view{__str}); } @@ -296,7 +297,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION constexpr size_type find(const _CharT* __str, size_type __pos, size_type __n) const noexcept; - constexpr size_type + __attribute__((__nonnull__)) constexpr size_type find(const _CharT* __str, size_type __pos = 0) const noexcept { return this->find(__str, __pos, traits_type::length(__str)); } @@ -310,7 +311,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION constexpr size_type rfind(const _CharT* __str, size_type __pos, size_type __n) const noexcept; - constexpr size_type + __attribute__((__nonnull__)) constexpr size_type rfind(const _CharT* __str, size_type __pos = npos) const noexcept { return this->rfind(__str, __pos, traits_type::length(__str)); } @@ -323,9 +324,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION { return this->find(__c, __pos); } constexpr size_type - find_first_of(const _CharT* __str, size_type __pos, size_type __n) const noexcept; + find_first_of(const _CharT* __str, size_type __pos, + size_type __n) const noexcept; - constexpr size_type + __attribute__((__nonnull__)) constexpr size_type find_first_of(const _CharT* __str, size_type __pos = 0) const noexcept { return this->find_first_of(__str, __pos, traits_type::length(__str)); } @@ -342,7 +344,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION find_last_of(const _CharT* __str, size_type __pos, size_type __n) const noexcept; - constexpr size_type + __attribute__((__nonnull__)) constexpr size_type find_last_of(const _CharT* __str, size_type __pos = npos) const noexcept { return this->find_last_of(__str, __pos, traits_type::length(__str)); } @@ -358,7 +360,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION find_first_not_of(const _CharT* __str, size_type __pos, size_type __n) const noexcept; - constexpr size_type + __attribute__((__nonnull__)) constexpr size_type find_first_not_of(const _CharT* __str, size_type __pos = 0) const noexcept { return this->find_first_not_of(__str, __pos, @@ -377,7 +379,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION find_last_not_of(const _CharT* __str, size_type __pos, size_type __n) const noexcept; - constexpr size_type + __attribute__((__nonnull__)) constexpr size_type find_last_not_of(const _CharT* __str, size_type __pos = npos) const noexcept { diff --git a/libstdc++-v3/testsuite/21_strings/basic_string_view/cons/char/nonnull.cc b/libstdc++-v3/testsuite/21_strings/basic_string_view/cons/char/nonnull.cc new file mode 100644 index 00000000000..463ece718bd --- /dev/null +++ b/libstdc++-v3/testsuite/21_strings/basic_string_view/cons/char/nonnull.cc @@ -0,0 +1,29 @@ +// Copyright (C) 2018 Free Software Foundation, Inc. +// +// This file is part of the GNU ISO C++ Library. This library is free +// software; you can redistribute it and/or modify it under the +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 3, or (at your option) +// any later version. + +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. + +// You should have received a copy of the GNU General Public License along +// with this library; see the file COPYING3. If not see +// . + +// { dg-options "-std=gnu++17 -Wnonnull" } +// { dg-do compile { target c++17 } } + +#include + +void +test01() +{ + std::string_view s((const char*)nullptr); // { dg-warning "null arg" } + std::string_view t((char*)nullptr); // { dg-warning "null arg" } + std::string_view u(nullptr); // { dg-warning "null arg" } +} diff --git a/libstdc++-v3/testsuite/21_strings/basic_string_view/cons/wchar_t/nonnull.cc b/libstdc++-v3/testsuite/21_strings/basic_string_view/cons/wchar_t/nonnull.cc new file mode 100644 index 00000000000..8df61427a49 --- /dev/null +++ b/libstdc++-v3/testsuite/21_strings/basic_string_view/cons/wchar_t/nonnull.cc @@ -0,0 +1,29 @@ +// Copyright (C) 2018 Free Software Foundation, Inc. +// +// This file is part of the GNU ISO C++ Library. This library is free +// software; you can redistribute it and/or modify it under the +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 3, or (at your option) +// any later version. + +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. + +// You should have received a copy of the GNU General Public License along +// with this library; see the file COPYING3. If not see +// . + +// { dg-options "-std=gnu++17 -Wnonnull" } +// { dg-do compile { target c++17 } } + +#include + +void +test01() +{ + std::wstring_view s((const wchar_t*)nullptr); // { dg-warning "null arg" } + std::wstring_view t((wchar_t*)nullptr); // { dg-warning "null arg" } + std::wstring_view u(nullptr); // { dg-warning "null arg" } +} diff --git a/libstdc++-v3/testsuite/21_strings/basic_string_view/operations/compare/char/nonnull.cc b/libstdc++-v3/testsuite/21_strings/basic_string_view/operations/compare/char/nonnull.cc new file mode 100644 index 00000000000..1d12b700d88 --- /dev/null +++ b/libstdc++-v3/testsuite/21_strings/basic_string_view/operations/compare/char/nonnull.cc @@ -0,0 +1,29 @@ +// Copyright (C) 2018 Free Software Foundation, Inc. +// +// This file is part of the GNU ISO C++ Library. This library is free +// software; you can redistribute it and/or modify it under the +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 3, or (at your option) +// any later version. + +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. + +// You should have received a copy of the GNU General Public License along +// with this library; see the file COPYING3. If not see +// . + +// { dg-options "-std=gnu++17 -Wnonnull" } +// { dg-do compile { target c++17 } } + +#include + +int +test01() +{ + std::string_view s = "abcd"; + return s.compare((const char*)nullptr); // { dg-warning "null arg" } + return s.compare(0, 2, (const char*)nullptr); // { dg-warning "null arg" } +} diff --git a/libstdc++-v3/testsuite/21_strings/basic_string_view/operations/find/char/nonnull.cc b/libstdc++-v3/testsuite/21_strings/basic_string_view/operations/find/char/nonnull.cc new file mode 100644 index 00000000000..69f1850d9dc --- /dev/null +++ b/libstdc++-v3/testsuite/21_strings/basic_string_view/operations/find/char/nonnull.cc @@ -0,0 +1,33 @@ +// Copyright (C) 2018 Free Software Foundation, Inc. +// +// This file is part of the GNU ISO C++ Library. This library is free +// software; you can redistribute it and/or modify it under the +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 3, or (at your option) +// any later version. + +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. + +// You should have received a copy of the GNU General Public License along +// with this library; see the file COPYING3. If not see +// . + +// { dg-options "-std=gnu++17 -Wnonnull" } +// { dg-do compile { target c++17 } } + +#include + +int +test01() +{ + std::string_view s = "abcd"; + return s.find((const char*)nullptr); // { dg-warning "null arg" } + return s.find((const char*)nullptr, 1); // { dg-warning "null arg" } + return s.find_first_of((const char*)nullptr); // { dg-warning "null arg" } + return s.find_first_of((const char*)nullptr, 1); // { dg-warning "null arg" } + return s.find_first_not_of((const char*)nullptr); // { dg-warning "null arg" } + return s.find_first_not_of((const char*)nullptr, 1); // { dg-warning "null arg" } +} diff --git a/libstdc++-v3/testsuite/21_strings/basic_string_view/operations/rfind/char/nonnull.cc b/libstdc++-v3/testsuite/21_strings/basic_string_view/operations/rfind/char/nonnull.cc new file mode 100644 index 00000000000..ca8527afa58 --- /dev/null +++ b/libstdc++-v3/testsuite/21_strings/basic_string_view/operations/rfind/char/nonnull.cc @@ -0,0 +1,29 @@ +// Copyright (C) 2018 Free Software Foundation, Inc. +// +// This file is part of the GNU ISO C++ Library. This library is free +// software; you can redistribute it and/or modify it under the +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 3, or (at your option) +// any later version. + +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. + +// You should have received a copy of the GNU General Public License along +// with this library; see the file COPYING3. If not see +// . + +// { dg-options "-std=gnu++17 -Wnonnull" } +// { dg-do compile { target c++17 } } + +#include + +int +test01() +{ + std::string_view s = "abcd"; + return s.rfind((const char*)nullptr); // { dg-warning "null arg" } + return s.rfind((const char*)nullptr, 1); // { dg-warning "null arg" } +} -- 2.30.2