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.

diff --git a/compat/os/macosx.h b/compat/os/macosx.h
index 21c17a23e9273fc43450821f20c2bcb6b5d9caac..c28affe7671d6e6d32a551cfec200a6b9b45ea9d 100644 (file)
--- 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 00e2bef212ef833ed7023996b01412d4c6266cf9..4bc4efc33fc0a937031b322c3951d8c60f5fed94 100644 (file)
--- 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 0f8275b17893ebe244eea31a327e41a8e1d392e7..d0a55281ce0d7cd4c75eac1d0a360cc6a96b150c 100644 (file)
--- 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 (file)
index 39fcee0..0000000
--- a/include/SquidNew.h
+++ /dev/null
@@ -1,41 +0,0 @@
-/*
- * Copyright (C) 1996-2017 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 <new>
-
-_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 706d74e73299aea0fd21629ef2d56a2f1050db3f..3abd6506dd169c82608e0ab47d11bfecfd7e0987 100644 (file)
--- 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 e38faa299c2b26b695e355e1a7f42ff1b2af25dd..e975eff1665ac37c66f2e8f21c3d4c02fd62c3b8 100644 (file)
--- a/src/SquidNew.cc
+++ b/src/SquidNew.cc
@@ -8,29 +8,45 @@
 
 /* DEBUG: none          Memory Allocation */
 
-#define _SQUID_EXTERNNEW_
-
 #include "squid.h"
 
-#ifdef __SUNPRO_CC
+#if !defined(__clang__)
 
 #include <new>
-void *operator new(size_t size) throw (std::bad_alloc)
+
+void *operator new(size_t size)
+{
+    return xmalloc(size);
+}
+void operator delete(void *address)
+{
+    xfree(address);
+}
+void *operator new[](size_t size)
+{
+    return xmalloc(size);
+}
+void operator delete[](void *address)
+{
+    xfree(address);
+}
+
+void *operator new(size_t size, const std::nothrow_t &tag)
 {
     return xmalloc(size);
 }
-void operator delete (void *address) throw()
+void operator delete(void *address, const std::nothrow_t &tag)
 {
-    xfree (address);
+    xfree(address);
 }
-void *operator new[] (size_t size) throw (std::bad_alloc)
+void *operator new[](size_t size, const std::nothrow_t &tag)
 {
     return xmalloc(size);
 }
-void operator delete[] (void *address) throw()
+void operator delete[](void *address, const std::nothrow_t &tag)
 {
-    xfree (address);
+    xfree(address);
 }
 
-#endif /* __SUNPRO_CC */
+#endif /* !defined(__clang__) */