From 39cca4e121215f3f994c1e57f7201ad2a2a2d32a Mon Sep 17 00:00:00 2001 From: Alex Rousskov Date: Sat, 28 May 2016 00:46:02 +1200 Subject: [PATCH] Replace new/delete operators using modern C++ rules. This change was motivated by "Mismatched free()/delete/delete[]" errors reported by valgrind and mused about in Squid source code. I speculate that the old new/delete replacement code was the result of slow accumulation of working hacks to accomodate various environments, as compiler support for the feature evolved. The cumulative result does not actually work well (see the above paragraph), and the replacement functions had the following visible coding problems according to [1,2]: a) Declared with non-standard profiles that included throw specifiers. b) Declared inline. C++ says that the results of inline declarations have unspecified effects. In Squid, they probably necessitated complex compiler-specific "extern inline" workarounds. c) Defined in the header file. C++ says that defining replacements "in any source file" is enough and that multiple replacements per program (which is what a header file definition produces) result in "undefined behavior". d) Declared inconsistently (only 2 out of 4 flavors). Declaring one base flavor should be sufficient, but if we declare more, we should declare all of them. [1] http://en.cppreference.com/w/cpp/memory/new/operator_new [2] http://en.cppreference.com/w/cpp/memory/new/operator_delete The replacements were not provided to clang (trunk r13219), but there was no explanation why. This patch does not change that exclusion. I have no idea whether any of the old hacks are still necessary in some cases. However, I suspect that either we do not care much if the replacements are not enabled on some poorly supported platforms OR we can disable them (or make them work) using much simpler hacks for the platforms we do care about. --- compat/os/macosx.h | 5 ----- compat/os/sgi.h | 9 --------- compat/os/solaris.h | 7 ------- include/SquidNew.h | 41 ----------------------------------------- include/util.h | 17 ----------------- src/SquidNew.cc | 35 +++++++++++++++++++++++++---------- 6 files changed, 25 insertions(+), 89 deletions(-) delete mode 100644 include/SquidNew.h diff --git a/compat/os/macosx.h b/compat/os/macosx.h index c95bf0a687..aff3862962 100644 --- a/compat/os/macosx.h +++ b/compat/os/macosx.h @@ -28,11 +28,6 @@ #include "compat/cmsg.h" -// MacOS GCC 4.0.1 and 4.2.1 supply __GNUC_GNU_INLINE__ but do not actually define __attribute__((gnu_inline)) -#if defined(__cplusplus) && !defined(_SQUID_EXTERNNEW_) -#define _SQUID_EXTERNNEW_ extern inline -#endif - #endif /* _SQUID_APPLE_ */ #endif /* SQUID_OS_MACOSX_H */ diff --git a/compat/os/sgi.h b/compat/os/sgi.h index 114253a014..0ad09fdc60 100644 --- a/compat/os/sgi.h +++ b/compat/os/sgi.h @@ -25,15 +25,6 @@ #define _ABI_SOURCE #endif /* USE_ASYNC_IO */ -#if defined(__cplusplus) && !defined(_SQUID_EXTERNNEW_) && !defined(_GNUC_) -/* - * The gcc compiler treats extern inline functions as being extern, - * while the SGI MIPSpro compilers treat them as inline. To get equivalent - * behavior, remove the inline keyword. - */ -#define _SQUID_EXTERNNEW_ extern -#endif - #endif /* _SQUID_SGI_ */ #endif /* SQUID_OS_SGI_H */ diff --git a/compat/os/solaris.h b/compat/os/solaris.h index d83a6ce190..7e8ad463cf 100644 --- a/compat/os/solaris.h +++ b/compat/os/solaris.h @@ -58,13 +58,6 @@ SQUIDCEXTERN int getpagesize(void); SQUIDCEXTERN int gethostname(char *, int); #endif -/* - * SunPro CC handles extern inline as inline, PLUS extern symbols. - */ -#if !defined(_SQUID_EXTERNNEW_) && defined(__SUNPRO_CC) -#define _SQUID_EXTERNNEW_ extern -#endif - /* * SunStudio CC does not define C++ portability API __FUNCTION__ */ diff --git a/include/SquidNew.h b/include/SquidNew.h deleted file mode 100644 index 32f20abf8f..0000000000 --- a/include/SquidNew.h +++ /dev/null @@ -1,41 +0,0 @@ -/* - * Copyright (C) 1996-2016 The Squid Software Foundation and contributors - * - * Squid software is distributed under GPLv2+ license and includes - * contributions from numerous individuals and organizations. - * Please see the COPYING and CONTRIBUTORS files for details. - */ - -#ifndef SQUID_NEW_H -#define SQUID_NEW_H - -#if !defined(__SUNPRO_CC) && !defined(__clang__) -/* Any code using libstdc++ must have externally resolvable overloads - * for void * operator new - which means in the .o for the binary, - * or in a shared library. static libs don't propogate the symbol - * so, look in the translation unit containing main() in squid - * for the extern version in squid - */ -#include - -_SQUID_EXTERNNEW_ void *operator new(size_t size) throw (std::bad_alloc) -{ - return xmalloc(size); -} -_SQUID_EXTERNNEW_ void operator delete (void *address) throw() -{ - xfree(address); -} -_SQUID_EXTERNNEW_ void *operator new[] (size_t size) throw (std::bad_alloc) -{ - return xmalloc(size); -} -_SQUID_EXTERNNEW_ void operator delete[] (void *address) throw() -{ - xfree(address); -} - -#endif /* !__SUNPRO_CC && !__clang__*/ - -#endif /* SQUID_NEW_H */ - diff --git a/include/util.h b/include/util.h index 15c7cf0c34..a32e47657b 100644 --- a/include/util.h +++ b/include/util.h @@ -19,23 +19,6 @@ SQUIDCEXTERN int tvSubUsec(struct timeval, struct timeval); SQUIDCEXTERN double tvSubDsec(struct timeval, struct timeval); SQUIDCEXTERN void Tolower(char *); -#if defined(__cplusplus) -/* - * Any code using libstdc++ must have externally resolvable overloads - * for void * operator new - which means in the .o for the binary, - * or in a shared library. static libs don't propogate the symbol - * so, look in the translation unit containing main() in squid - * for the extern version in squid - */ -#if !defined(_SQUID_EXTERNNEW_) -#if defined(__GNUC_STDC_INLINE__) || defined(__GNUC_GNU_INLINE__) -#define _SQUID_EXTERNNEW_ extern inline __attribute__((gnu_inline)) -#else -#define _SQUID_EXTERNNEW_ extern inline -#endif -#endif -#include "SquidNew.h" -#endif SQUIDCEXTERN time_t parse_iso3307_time(const char *buf); diff --git a/src/SquidNew.cc b/src/SquidNew.cc index ab26adb71d..e32847ea6e 100644 --- a/src/SquidNew.cc +++ b/src/SquidNew.cc @@ -8,29 +8,44 @@ /* DEBUG: none Memory Allocation */ -#define _SQUID_EXTERNNEW_ - #include "squid.h" -#ifdef __SUNPRO_CC +#if !defined(__clang__) #include -void *operator new(size_t size) throw (std::bad_alloc) + +void *operator new(size_t size) { return xmalloc(size); } -void operator delete (void *address) throw() +void operator delete(void *address) { - xfree (address); + xfree(address); } -void *operator new[] (size_t size) throw (std::bad_alloc) +void *operator new[](size_t size) { return xmalloc(size); } -void operator delete[] (void *address) throw() +void operator delete[](void *address) { - xfree (address); + xfree(address); } -#endif /* __SUNPRO_CC */ +void *operator new(size_t size, const std::nothrow_t &tag) +{ + return xmalloc(size); +} +void operator delete(void *address, const std::nothrow_t &tag) +{ + xfree(address); +} +void *operator new[](size_t size, const std::nothrow_t &tag) +{ + return xmalloc(size); +} +void operator delete[](void *address, const std::nothrow_t &tag) +{ + xfree(address); +} +#endif /* !defined(__clang__) */ -- 2.47.2