C++Talk.NET C++ language newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  Is how to lay out the constant string compiler dependent?          C++Talk.NET Forum Index -> C Language View previous topic :: View next topic   Author Message Quentin Yuan Guest Posted: Thu May 17, 2007 9:11 am    Post subject: Is how to lay out the constant string compiler dependent? I always consider that the constant character strings of which literal value are the same lay out at the same logic address, in another words, every constant character string have only one copy in the program. My view base on that if it doesn't that, you lose the memory of the string that you have used except store the address in a pointer, this is a form of memory leak although it doesn't really eat the memory as the general memory leak. The x86 machine always support my view:-) But recently someone told me that the addresses of the same character strings are not the same in SunOS, so it seems that how to lay out the constant strings is complier dependent. If it's true, I wonder the reason why my view is wrong? Both informations and links are appreciated. Thanks to all! Best Regards Back to top Chris Dollin Guest Posted: Thu May 17, 2007 9:11 am    Post subject: Re: Is how to lay out the constant string compiler dependent Quentin Yuan wrote: Quote: I always consider that the constant character strings of which literal value are the same lay out at the same logic address, in another words, every constant character string have only one copy in the program. My view base on that if it doesn't that, you lose the memory of the string that you have used except store the address in a pointer, this is a form of memory leak although it doesn't really eat the memory as the general memory leak. The x86 machine always support my view:-) But recently someone told me that the addresses of the same character strings are not the same in SunOS, so it seems that how to lay out the constant strings is complier dependent. If it's true, I wonder the reason why my view is wrong? Both informations and links are appreciated. Thanks to all! A C implementation is allowed, but not required, to collapse identical string literals (and parts thereof). While it's /nice/ to be able to save space this way, it does require a certain amount of sophistication in the implementation -- the linker (or its equivalent) must be able to identify the equal areas /and know that it can collapse them/. Some linkers don't have the language to be told that. It would not surprise me if an implementation shared literals in the same compilation unit even if it couldn't do so across units. -- "Possibly you're not recalling some of his previous plans." Zoe, /Firefly/ Hewlett-Packard Limited registered no: registered office: Cain Road, Bracknell, Berks RG12 1HN 690597 England Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         C++Talk.NET Forum Index -> C Language All times are GMT Page 1 of 1   Jump to: Select a forum C/C++----------------C LanguageC Language (Moderated)C++ Language (Moderated)C++ language (comp.lang.c++)C++ language, library and standards Non-English C/C++ Newsgroups----------------C++ (German)C++ (French)  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum Powered by phpBB © 2001, 2006 phpBB Group SEO toolkit © 2004-2006 webmedic.