DMARC-Filter: OpenDMARC Filter v1.4.2 delorie.com 56P5g5mt1871271
DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 7E0BD385E011
Date: Thu, 24 Jul 2025 22:41:04 -0700 (PDT)
To: cygwin AT cygwin DOT com
Subject: new c++ new/delete overloads need wrapping?
Message-ID: <81535510-8360-1c72-442a-0b630a6d937f@jdrake.com>
MIME-Version: 1.0
From: Jeremy Drake via Cygwin <cygwin AT cygwin DOT com>
Reply-To: Jeremy Drake <cygwin AT jdrake DOT com>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Sender: "Cygwin" <cygwin-bounces~archive-cygwin=delorie DOT com AT cygwin DOT com>

I was looking into C++ new/delete --wrap linker options, and noticed that
in a quick test the wrapper for delete was not being called.  This was
because delete is being compiled to _ZdlPvm and that symbol is not present
in the --wrap arguments in the GCC spec, and is not part of the
per_process_cxx_malloc struct.  I'm not seeing anything in that cxx_malloc
struct like a size or version number, so I don't know a good way to
extend it given that it is part of the startup code linked into every
binary.

Here are the current symbols from libc++ and how they demangle:

_ZdaPv	operator delete[](void*)
_ZdaPvm	operator delete[](void*, unsigned long)
_ZdaPvmSt11align_val_t	operator delete[](void*, unsigned long, std::align_val_t)
_ZdaPvRKSt9nothrow_t	operator delete[](void*, std::nothrow_t const&)
_ZdaPvSt11align_val_t	operator delete[](void*, std::align_val_t)
_ZdaPvSt11align_val_tRKSt9nothrow_t	operator delete[](void*, std::align_val_t, std::nothrow_t const&)
_ZdlPv	operator delete(void*)
_ZdlPvm	operator delete(void*, unsigned long)
_ZdlPvmSt11align_val_t	operator delete(void*, unsigned long, std::align_val_t)
_ZdlPvRKSt9nothrow_t	operator delete(void*, std::nothrow_t const&)
_ZdlPvSt11align_val_t	operator delete(void*, std::align_val_t)
_ZdlPvSt11align_val_tRKSt9nothrow_t	operator delete(void*, std::align_val_t, std::nothrow_t const&)
_Znam	operator new[](unsigned long)
_ZnamRKSt9nothrow_t	operator new[](unsigned long, std::nothrow_t const&)
_ZnamSt11align_val_t	operator new[](unsigned long, std::align_val_t)
_ZnamSt11align_val_tRKSt9nothrow_t	operator new[](unsigned long, std::align_val_t, std::nothrow_t const&)
_Znwm	operator new(unsigned long)
_ZnwmRKSt9nothrow_t	operator new(unsigned long, std::nothrow_t const&)
_ZnwmSt11align_val_t	operator new(unsigned long, std::align_val_t)
_ZnwmSt11align_val_tRKSt9nothrow_t	operator new(unsigned long, std::align_val_t, std::nothrow_t const&)


-- 
Problem reports:      https://cygwin.com/problems.html
FAQ:                  https://cygwin.com/faq/
Documentation:        https://cygwin.com/docs.html
Unsubscribe info:     https://cygwin.com/ml/#unsubscribe-simple