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 c95bf0a6879ccfd8820100562fbc598622edb05f..aff3862962737b62a7dcce173da6d92cd7dee644 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 114253a0142ecf1ae09e05ef6398fc7046cc84e8..0ad09fdc60ac21bf65217ae7a0d7306097ca6ade 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 d83a6ce1904393aa0e1f956f8d16ccb5cd358e10..7e8ad463cf54636805169d5fa3eea729562995dc 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 32f20ab..0000000
--- 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 <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 15c7cf0c34400b4f2a16968ca8d06801d1f376c0..a32e47657bf2748adc3fd862433bb1d5e4252ef5 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 ab26adb71de2d2035a04e175a8c4a1347679dd75..e32847ea6e85847a8a08b593212341f81c9607d9 100644 (file)
--- 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 <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) 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__) */