diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 1814910558b..933e4e9f0a8 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,11 @@ +2017-10-16 David Malcolm + + * Makefile.in (OBJS): Add unique-ptr-tests.o. + * selftest-run-tests.c (selftest::run_tests): Call + selftest::unique_ptr_tests_cc_tests. + * selftest.h (selftest::unique_ptr_tests_cc_tests): New decl. + * unique-ptr-tests.cc: New file. + 2017-10-16 Vladimir Makarov PR sanitizer/82353 diff --git a/gcc/Makefile.in b/gcc/Makefile.in index 878ce7bc452..2809619031b 100644 --- a/gcc/Makefile.in +++ b/gcc/Makefile.in @@ -1568,6 +1568,7 @@ OBJS = \ tree-vrp.o \ tree.o \ typed-splay-tree.o \ + unique-ptr-tests.o \ valtrack.o \ value-prof.o \ var-tracking.o \ diff --git a/gcc/selftest-run-tests.c b/gcc/selftest-run-tests.c index 5c84f3a0737..11bf0cc9cb7 100644 --- a/gcc/selftest-run-tests.c +++ b/gcc/selftest-run-tests.c @@ -67,6 +67,7 @@ selftest::run_tests () sreal_c_tests (); fibonacci_heap_c_tests (); typed_splay_tree_c_tests (); + unique_ptr_tests_cc_tests (); /* Mid-level data structures. */ input_c_tests (); diff --git a/gcc/selftest.h b/gcc/selftest.h index 2e649a70b9e..6478922cd2c 100644 --- a/gcc/selftest.h +++ b/gcc/selftest.h @@ -195,6 +195,7 @@ extern void store_merging_c_tests (); extern void typed_splay_tree_c_tests (); extern void tree_c_tests (); extern void tree_cfg_c_tests (); +extern void unique_ptr_tests_cc_tests (); extern void vec_c_tests (); extern void wide_int_cc_tests (); extern void predict_c_tests (); diff --git a/gcc/unique-ptr-tests.cc b/gcc/unique-ptr-tests.cc new file mode 100644 index 00000000000..f5b72a8c15f --- /dev/null +++ b/gcc/unique-ptr-tests.cc @@ -0,0 +1,234 @@ +/* Unit tests for unique-ptr.h. + Copyright (C) 2017 Free Software Foundation, Inc. + +This file is part of GCC. + +GCC 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. + +GCC 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 GCC; see the file COPYING3. If not see +. */ + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "unique-ptr.h" +#include "selftest.h" + +#if CHECKING_P + +namespace selftest { + +namespace { + +/* A class for counting ctor and dtor invocations. */ + +struct stats +{ + stats () : ctor_count (0), dtor_count (0) {} + + int ctor_count; + int dtor_count; +}; + +/* A class that uses "stats" to track its ctor and dtor invocations. */ + +class foo +{ +public: + foo (stats &s) : m_s (s) { ++m_s.ctor_count; } + ~foo () { ++m_s.dtor_count; } + + int example_method () const { return 42; } + +private: + foo (const foo&); + foo & operator= (const foo &); + +private: + stats &m_s; +}; + +/* A struct for testing unique_ptr. */ + +struct has_default_ctor +{ + has_default_ctor () : m_field (42) {} + int m_field; +}; + +/* A dummy struct for testing unique_xmalloc_ptr. */ + +struct dummy +{ + int field; +}; + +} // anonymous namespace + +/* Verify that the default ctor inits ptrs to NULL. */ + +static void +test_null_ptr () +{ + gnu::unique_ptr p; + ASSERT_EQ (NULL, p); + + gnu::unique_xmalloc_ptr q; + ASSERT_EQ (NULL, q); +} + +/* Verify that deletion happens when a unique_ptr goes out of scope. */ + +static void +test_implicit_deletion () +{ + stats s; + ASSERT_EQ (0, s.ctor_count); + ASSERT_EQ (0, s.dtor_count); + + { + gnu::unique_ptr f (new foo (s)); + ASSERT_NE (NULL, f); + ASSERT_EQ (1, s.ctor_count); + ASSERT_EQ (0, s.dtor_count); + } + + /* Verify that the foo was implicitly deleted. */ + ASSERT_EQ (1, s.ctor_count); + ASSERT_EQ (1, s.dtor_count); +} + +/* Verify that we can assign to a NULL unique_ptr. */ + +static void +test_overwrite_of_null () +{ + stats s; + ASSERT_EQ (0, s.ctor_count); + ASSERT_EQ (0, s.dtor_count); + + { + gnu::unique_ptr f; + ASSERT_EQ (NULL, f); + ASSERT_EQ (0, s.ctor_count); + ASSERT_EQ (0, s.dtor_count); + + /* Overwrite with a non-NULL value. */ + f = gnu::unique_ptr (new foo (s)); + ASSERT_EQ (1, s.ctor_count); + ASSERT_EQ (0, s.dtor_count); + } + + /* Verify that the foo is implicitly deleted. */ + ASSERT_EQ (1, s.ctor_count); + ASSERT_EQ (1, s.dtor_count); +} + +/* Verify that we can assign to a non-NULL unique_ptr. */ + +static void +test_overwrite_of_non_null () +{ + stats s; + ASSERT_EQ (0, s.ctor_count); + ASSERT_EQ (0, s.dtor_count); + + { + gnu::unique_ptr f (new foo (s)); + ASSERT_NE (NULL, f); + ASSERT_EQ (1, s.ctor_count); + ASSERT_EQ (0, s.dtor_count); + + /* Overwrite with a different value. */ + f = gnu::unique_ptr (new foo (s)); + ASSERT_EQ (2, s.ctor_count); + ASSERT_EQ (1, s.dtor_count); + } + + /* Verify that the 2nd foo was implicitly deleted. */ + ASSERT_EQ (2, s.ctor_count); + ASSERT_EQ (2, s.dtor_count); +} + +/* Verify that unique_ptr's overloaded ops work. */ + +static void +test_overloaded_ops () +{ + stats s; + gnu::unique_ptr f (new foo (s)); + ASSERT_EQ (42, f->example_method ()); + ASSERT_EQ (42, (*f).example_method ()); + ASSERT_EQ (f, f); + ASSERT_NE (NULL, f.get ()); + + gnu::unique_ptr g (new foo (s)); + ASSERT_NE (f, g); +} + +/* Verify that the gnu::unique_ptr specialization for T[] works. */ + +static void +test_array_new () +{ + const int num = 10; + gnu::unique_ptr p (new has_default_ctor[num]); + ASSERT_NE (NULL, p.get ()); + /* Verify that operator[] works, and that the default ctor was called + on each element. */ + for (int i = 0; i < num; i++) + ASSERT_EQ (42, p[i].m_field); +} + +/* Verify that gnu::unique_xmalloc_ptr works. */ + +static void +test_xmalloc () +{ + gnu::unique_xmalloc_ptr p (XNEW (dummy)); + ASSERT_NE (NULL, p.get ()); +} + +/* Verify the gnu::unique_xmalloc_ptr specialization for T[]. */ + +static void +test_xmalloc_array () +{ + const int num = 10; + gnu::unique_xmalloc_ptr p (XNEWVEC (dummy, num)); + ASSERT_NE (NULL, p.get ()); + + /* Verify that operator[] works. */ + for (int i = 0; i < num; i++) + p[i].field = 42; + for (int i = 0; i < num; i++) + ASSERT_EQ (42, p[i].field); +} + +/* Run all of the selftests within this file. */ + +void +unique_ptr_tests_cc_tests () +{ + test_null_ptr (); + test_implicit_deletion (); + test_overwrite_of_null (); + test_overwrite_of_non_null (); + test_overloaded_ops (); + test_array_new (); + test_xmalloc (); + test_xmalloc_array (); +} + +} // namespace selftest + +#endif /* #if CHECKING_P */ diff --git a/include/ChangeLog b/include/ChangeLog index 0221586d778..805e81c0227 100644 --- a/include/ChangeLog +++ b/include/ChangeLog @@ -1,3 +1,8 @@ +2017-10-16 Trevor Saunders + David Malcolm + + * unique-ptr.h: New file. + 2017-09-15 Yao Qi Pedro Alves diff --git a/include/unique-ptr.h b/include/unique-ptr.h new file mode 100644 index 00000000000..c5ca031c284 --- /dev/null +++ b/include/unique-ptr.h @@ -0,0 +1,403 @@ +/* gnu::unique_ptr, a simple std::unique_ptr replacement for C++03. + + Copyright (C) 2007-2016 Free Software Foundation, Inc. + + This file is part of GCC. + + This program 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 of the License, or + (at your option) any later version. + + This program 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 program. If not, see . */ + +/* gnu::unique_ptr defines a C++ owning smart pointer that exposes a + subset of the std::unique_ptr API. + + In fact, when compiled with a C++11 compiler, gnu::unique_ptr + actually _is_ std::unique_ptr. When compiled with a C++03 compiler + OTOH, it's an hand coded std::unique_ptr emulation that assumes + code is correct and doesn't try to be too smart. + + This supports custom deleters, but not _stateful_ deleters, so you + can't use those in C++11 mode either. Only the managed pointer is + stored in the smart pointer. That could be changed; it simply + wasn't found necessary. + + At the end of the file you'll find a gnu::unique_ptr partial + specialization that uses a custom (stateless) deleter: + gnu::unique_xmalloc_ptr. That is used to manage pointers to + objects allocated with xmalloc. + + The C++03 version was originally based on GCC 7.0's std::auto_ptr + and then heavily customized to behave more like C++11's + std::unique_ptr, but at this point, it no longer shares much at all + with the original file. But, that's the history and the reason for + the copyright's starting year. + + The C++03 version lets you shoot yourself in the foot, since + similarly to std::auto_ptr, the copy constructor and assignment + operators actually move. Also, in the name of simplicity, no + effort is spent on using SFINAE to prevent invalid conversions, + etc. This is not really a problem, because the goal here is to + allow code that would be correct using std::unique_ptr to be + equally correct in C++03 mode, and, just as efficient. If client + code compiles correctly with a C++11 (or newer) compiler, we know + we're not doing anything invalid by mistake. + + Usage notes: + + - Putting gnu::unique_ptr in standard containers is not supported, + since C++03 containers are not move-aware (and our emulation + relies on copy actually moving). + + - Since there's no nullptr in C++03, gnu::unique_ptr allows + implicit initialization and assignment from NULL instead. + + - To check whether there's an associated managed object, all these + work as expected: + + if (ptr) + if (!ptr) + if (ptr != NULL) + if (ptr == NULL) + if (NULL != ptr) + if (NULL == ptr) +*/ + +#ifndef GNU_UNIQUE_PTR_H +#define GNU_UNIQUE_PTR_H 1 + +#include + +namespace gnu +{ + +#if __cplusplus >= 201103 + +/* In C++11 mode, all we need is import the standard + std::unique_ptr. */ +template using unique_ptr = std::unique_ptr; + +/* Pull in move as well. */ +using std::move; + +#else /* C++11 */ + +/* Default destruction policy used by gnu::unique_ptr when no deleter + is specified. Uses delete. */ + +template +struct default_delete +{ + void operator () (T *ptr) const { delete ptr; } +}; + +/* Specialization for arrays. Uses delete[]. */ + +template +struct default_delete +{ + void operator () (T *ptr) const { delete [] ptr; } +}; + +namespace detail +{ +/* Type used to support implicit construction from NULL: + + gnu::unique_ptr func (....) + { + return NULL; + } + + and assignment from NULL: + + gnu::unique_ptr ptr (....); + ... + ptr = NULL; + + It is intentionally not defined anywhere. */ +struct nullptr_t; + +/* Base class of our unique_ptr emulation. Contains code common to + both unique_ptr and unique_ptr. */ + +template +class unique_ptr_base +{ +public: + typedef T *pointer; + typedef T element_type; + typedef D deleter_type; + + /* Takes ownership of a pointer. P is a pointer to an object of + element_type type. Defaults to NULL. */ + explicit unique_ptr_base (element_type *p = NULL) throw () : m_ptr (p) {} + + /* The "move" constructor. Really a copy constructor that actually + moves. Even though std::unique_ptr is not copyable, our little + simpler emulation allows it, because: + + - There are no rvalue references in C++03. Our move emulation + instead relies on copy/assignment moving, like std::auto_ptr. + - RVO/NRVO requires an accessible copy constructor + */ + unique_ptr_base (const unique_ptr_base &other) throw () + : m_ptr (const_cast (other).release ()) {} + + /* Converting "move" constructor. Really an lvalue ref converting + constructor that actually moves. This allows constructs such as: + + unique_ptr func_returning_unique_ptr (.....); + ... + unique_ptr ptr = func_returning_unique_ptr (.....); + */ + template + unique_ptr_base (const unique_ptr_base &other) throw () + : m_ptr (const_cast &> (other).release ()) {} + + /* The "move" assignment operator. Really an lvalue ref copy + assignment operator that actually moves. See comments above. */ + unique_ptr_base &operator= (const unique_ptr_base &other) throw () + { + reset (const_cast (other).release ()); + return *this; + } + + /* Converting "move" assignment. Really an lvalue ref converting + copy assignment operator that moves. See comments above. */ + template + unique_ptr_base &operator= (const unique_ptr_base &other) throw () + { + reset (const_cast &> (other).release ()); + return *this; + } + + /* std::unique_ptr does not allow assignment, except from nullptr. + nullptr doesn't exist in C++03, so we allow assignment from NULL + instead [ptr = NULL;]. + */ + unique_ptr_base &operator= (detail::nullptr_t *) throw () + { + reset (); + return *this; + } + + ~unique_ptr_base () { call_deleter (); } + + /* "explicit operator bool ()" emulation using the safe bool + idiom. */ +private: + typedef void (unique_ptr_base::*explicit_operator_bool) () const; + void this_type_does_not_support_comparisons () const {} + +public: + operator explicit_operator_bool () const + { + return (m_ptr != NULL + ? &unique_ptr_base::this_type_does_not_support_comparisons + : 0); + } + + element_type *get () const throw () { return m_ptr; } + + element_type *release () throw () + { + pointer tmp = m_ptr; + m_ptr = NULL; + return tmp; + } + + void reset (element_type *p = NULL) throw () + { + if (p != m_ptr) + { + call_deleter (); + m_ptr = p; + } + } + +private: + + /* Call the deleter. Note we assume the deleter is "stateless". */ + void call_deleter () + { + D d; + + d (m_ptr); + } + + element_type *m_ptr; +}; + +} /* namespace detail */ + +/* Macro used to create a unique_ptr_base "partial specialization" -- + a subclass that uses a specific deleter. Basically this re-defines + the necessary constructors. This is necessary because C++03 + doesn't support inheriting constructors with "using". While at it, + we inherit the assignment operator. TYPE is the name of the type + being defined. Assumes that 'base_type' is a typedef of the + baseclass TYPE is inheriting from. */ +#define DEFINE_GNU_UNIQUE_PTR(TYPE) \ +public: \ + explicit TYPE (T *p = NULL) throw () \ + : base_type (p) {} \ + \ + TYPE (const TYPE &other) throw () : base_type (other) {} \ + \ + TYPE (detail::nullptr_t *) throw () : base_type (NULL) {} \ + \ + template \ + TYPE (const detail::unique_ptr_base &other) throw () \ + : base_type (other) {} \ + \ + using base_type::operator=; + +/* Define single-object gnu::unique_ptr. */ + +template > +class unique_ptr : public detail::unique_ptr_base +{ + typedef detail::unique_ptr_base base_type; + + DEFINE_GNU_UNIQUE_PTR (unique_ptr) + +public: + /* Dereferencing. */ + T &operator* () const throw () { return *this->get (); } + T *operator-> () const throw () { return this->get (); } +}; + +/* Define gnu::unique_ptr specialization for T[]. */ + +template +class unique_ptr : public detail::unique_ptr_base +{ + typedef detail::unique_ptr_base base_type; + + DEFINE_GNU_UNIQUE_PTR (unique_ptr) + +public: + /* Indexing operator. */ + T &operator[] (size_t i) const { return this->get ()[i]; } +}; + +/* Comparison operators. */ + +template +inline bool +operator== (const detail::unique_ptr_base &x, + const detail::unique_ptr_base &y) +{ return x.get() == y.get(); } + +template +inline bool +operator!= (const detail::unique_ptr_base &x, + const detail::unique_ptr_base &y) +{ return x.get() != y.get(); } + +template +inline bool +operator< (const detail::unique_ptr_base &x, + const detail::unique_ptr_base &y) +{ return x.get() < y.get (); } + +template +inline bool +operator<= (const detail::unique_ptr_base &x, + const detail::unique_ptr_base &y) +{ return !(y < x); } + +template +inline bool +operator> (const detail::unique_ptr_base &x, + const detail::unique_ptr_base &y) +{ return y < x; } + +template +inline bool +operator>= (const detail::unique_ptr_base &x, + const detail::unique_ptr_base &y) +{ return !(x < y); } + +/* std::move "emulation". This is as simple as it can be -- no + attempt is made to emulate rvalue references. Instead relies on + the fact that gnu::unique_ptr has move semantics like + std::auto_ptr. I.e., copy/assignment actually moves. */ + +template +unique_ptr +move (unique_ptr v) +{ + return v; +} + +#endif /* C++11 */ + +/* Define gnu::unique_xmalloc_ptr, a gnu::unique_ptr that manages + xmalloc'ed memory. */ + +/* The deleter for gnu::unique_xmalloc_ptr. Uses free. */ +template +struct xmalloc_deleter +{ + void operator() (T *ptr) const { free (ptr); } +}; + +/* Same, for arrays. */ +template +struct xmalloc_deleter +{ + void operator() (T *ptr) const { free (ptr); } +}; + +#if __cplusplus >= 201103 + +/* In C++11, we just import the standard unique_ptr to our namespace + with a custom deleter. */ + +template using unique_xmalloc_ptr + = std::unique_ptr>; + +#else /* C++11 */ + +/* In C++03, we don't have template aliases, so we need to define a + subclass instead, and re-define the constructors, because C++03 + doesn't support inheriting constructors either. */ + +template +class unique_xmalloc_ptr : public unique_ptr > +{ + typedef unique_ptr > base_type; + + DEFINE_GNU_UNIQUE_PTR (unique_xmalloc_ptr) +}; + +/* Define gnu::unique_xmalloc_ptr specialization for T[]. */ + +template +class unique_xmalloc_ptr : public unique_ptr > +{ + typedef unique_ptr > base_type; + + DEFINE_GNU_UNIQUE_PTR (unique_xmalloc_ptr) +}; + +#endif /* C++11 */ + +} /* namespace gnu */ + +#endif /* GNU_UNIQUE_PTR_H */