[Bug c++/32984] add checking for array new delete
--- Comment #9 from dcb314 at hotmail dot com 2007-08-09 16:03 --- (In reply to comment #8) I suggest taking a technique from the STL and using an auto_array class In practice, I find both STL and Boost are rarely used. Such advanced tools are fine for experienced C++ programmers. For ex-Fortran programmers, new to C++, making their first steps in C++ manual memory management, the news that the C++ compiler will silently eat certainly wrong code is worrying. Hence my bug report. Some newbie C++ programmers need more hand-holding than traditional C++ compilers provide. And as C++ becomes more and more mainstream, this will be more and more true. The bug report remains at resolved wontfix. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32984
[Bug c++/32984] add checking for array new delete
--- Comment #8 from fang at csl dot cornell dot edu 2007-08-09 02:54 --- Please forgive a wee bit more noise on this matter: (Yes, I know this is resolved invalid) If you really insist on using a pointer instead of a valarray or vector, I suggest taking a technique from the STL and using an auto_array class template that delete []'s an array-allocated pointer automatically upon destruction (exception-safe too). Overload for member operator [] to do pointer arithmetic, for convenience. Taking the paradigm further, you can devise things like boost::shared_array (TR1?), or some sort of policy-driven pointer-class that performs The Appropriate Action (TM) upon destruction. If you're extremist, like me, and want to find/substitute *all* bare occurrences of operators new and delete (outside of certified pointer/array/vector classes), 'cpp | grep' for them, no g++ required. :) I can't remember the last time I botched any operation mismatch/typo/bug/error/unbalance. Of course, if you didn't actually make such an error, and the example was just a demonstration of your point, then I'm probably just preaching to the choir. [returns to lurking] -- fang at csl dot cornell dot edu changed: What|Removed |Added CC||fang at csl dot cornell dot ||edu http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32984
[Bug c++/32984] add checking for array new delete
--- Comment #7 from dcb314 at hotmail dot com 2007-08-06 16:06 --- (In reply to comment #6) This is one which you need huge dataflow analysis Doubtful. Yes/No/Don't know flag on each pointer data member of a class would be some of it. and whole program to detect this problem. I'd be happy with a one file solution to this problem, as I hope my original problem report made clear. In summary, my customer doesn't have HP kit, valgrind is run time and not compile time, the compiler isn't going to be fixed anytime soon so I feel a Perl script may be invented. So closing as won't fix. Fair enough. Point taken. I'll try a Perl script. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32984
[Bug c++/32984] add checking for array new delete
--- Comment #6 from pinskia at gcc dot gnu dot org 2007-08-05 19:37 --- This is not the business of a compiler to detect all and every programming mismatch. It can detect some but not all. This is one which you need huge dataflow analysis and whole program to detect this problem. This is not going to be inside GCC for a long time and even then it will not give good results. So closing as won't fix. -- pinskia at gcc dot gnu dot org changed: What|Removed |Added Status|UNCONFIRMED |RESOLVED Resolution||WONTFIX http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32984
[Bug c++/32984] add checking for array new delete
--- Comment #1 from gdr at cs dot tamu dot edu 2007-08-04 13:01 ---
Subject: Re: New: add checking for array new delete
dcb314 at hotmail dot com [EMAIL PROTECTED] writes:
| Given the following C++ code
|
| class K
| {
| public:
| void f();
| void g();
|
| private:
| int * a;
| double * b;
| float * c;
| unsigned int * d;
| };
|
| void K :: f()
| {
| a = new int;
| b = new double [ 10];
| delete c;
| delete [] d;
| }
|
| void K :: g()
| {
| delete [] a;// error
| delete b; // error
| c = new float [ 20];// error
| d = new unsigned int; // error
| }
|
| Recent snapshot g++ 4.3 20070803 can't find anything
| wrong with the code.
Special, dedicated tools exist for that task. I would suggest
you use one of them.
The above should not be the business of the *compiler*.
-- Gaby
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32984
[Bug c++/32984] add checking for array new delete
--- Comment #2 from dcb314 at hotmail dot com 2007-08-04 19:52 --- (In reply to comment #1) Special, dedicated tools exist for that task. Would you be willing to name three of them ? The above should not be the business of the *compiler*. Why not ? The compiler can generate a whole bunch of warnings already. Are you suggesting these existing warnings are none of the business of the compiler ? -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32984
Re: [Bug c++/32984] add checking for array new delete
dcb314 at hotmail dot com [EMAIL PROTECTED] writes: | The compiler can generate a whole bunch of warnings | already. Which fall in different mindset that the one you would like. -- Gaby
[Bug c++/32984] add checking for array new delete
--- Comment #3 from gdr at cs dot tamu dot edu 2007-08-04 22:06 --- Subject: Re: add checking for array new delete dcb314 at hotmail dot com [EMAIL PROTECTED] writes: | The compiler can generate a whole bunch of warnings | already. Which fall in different mindset that the one you would like. -- Gaby -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32984
[Bug c++/32984] add checking for array new delete
--- Comment #4 from gdr at cs dot tamu dot edu 2007-08-04 22:09 --- Subject: Re: add checking for array new delete dcb314 at hotmail dot com [EMAIL PROTECTED] writes: | (In reply to comment #1) | Special, dedicated tools exist for that task. | | Would you be willing to name three of them ? web searchers are your friends. look for valgrind and friends. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32984
[Bug c++/32984] add checking for array new delete
--- Comment #5 from sebor at roguewave dot com 2007-08-05 00:31 --- There are third party tools that track these types of problems. Some of them have started to make their way into compilers. For example, the HP static analysis tool called Code Adviser is integrated into the HP aCC compiler on IPF (see www.hp.com/go/cadvise). -- sebor at roguewave dot com changed: What|Removed |Added CC||sebor at roguewave dot com http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32984
