Re: [CMake] cmake -E create_symlink for Windows
On Sat, 2009-12-12 at 12:02 -0500, Bill Hoffman wrote: Alan W. Irwin wrote: On 2009-12-12 09:44-0500 David Cole wrote: On Fri, Dec 11, 2009 at 10:04 AM, Michael Wild them...@gmail.com wrote: Bummer. What where they THINKING??? (if at all...). It seems to me that M$ just CAN'T get it right. No matter how many times they try, how many good examples are out there, they always manage to seriously screw something up... Come to think of it, they probably were thinking about symlink-attacks... Come on. Let's make a deal: you don't bash Microsoft, Apple or Google here on the CMake mailing list and I won't bash Unix or Linux in any forum, anywhere, ever. OK? Does that sound cool? Absolutely. There used to be another poster here (before he got so-over-the-top that he was removed) that kept making gratuitous attacks on Linux and free software, and that was extremely annoying. So as a Linux developer I support Dave's call to be aware of other's strong feelings and stay on topic so we don't waste a lot of time here. Back on topic I am one of the lead developers of the PLplot CMake-based build system. However, my development experience is Linux only so I must rely on my Windows developer colleagues to catch any Linux-only or Unix-only mistakes I put into our build system. Up to this thread, I had no idea that there wasn't some reliable way to create symlinks on Windows, and it's only by chance that I haven't used create_symlink in any part of our build other than the Linux-only documentation build. Before this thread, I always assumed cmake -E commands gave you an excellent way to do common tasks in a cross-platform way. I appeal to the CMake developers to avoid from now on implementing any more CMake -E commands that have no hope of ever fulfilling that mandate, Also, please deprecate and document the cmake -E commands with obvious cross-platform limitations because otherwise your users are going to assume (like I did) that those commands are the recommended way to help make their project cross-platform. Is create_symlink an isolated case, or are there other cmake -E commands to worry about? Also, is create_symlink really a lost cross-platform cause? Reading later in Dave's post, it appears that the symlink concept does work on some Windows platform (he mentioned something about shortcuts). If there are intentions to make it work on a number of Windows platforms eventually, but that just hasn't happened yet, then _warn_ about that issue (e.g., something like Unix-only for now in the documentation). Also, if the CMake -E command is run on a platform that doesn't support it something better than a silent failure should be the result. Some things just can not be done cross platform. For example reading/ writing the windows registry, creating an OSX application bundle, and sym-links. Also, some computers don't even have shared libraries. Should we disable those features from CMake? That said, the symlink command is the only -E that does not work cross platform. The -E create_symlink does return failure from main when called on windows. So, if you used it in a custom command which is the idea for -E stuff, it would fail in a noticeable way (the build would fail). If you call it from execute_process, you should be checking the return value as well. -Bill Just out of curiosity: how does Cygwin handle this whole symbolic link business? Marcel Loose. ___ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Follow this link to subscribe/unsubscribe: http://www.cmake.org/mailman/listinfo/cmake
Re: [CMake] cmake -E create_symlink for Windows
http://en.wikipedia.org/wiki/Symbolic_link#Cygwin_symbolic_links On Mon, Dec 14, 2009 at 3:28 AM, Marcel Loose lo...@astron.nl wrote: On Sat, 2009-12-12 at 12:02 -0500, Bill Hoffman wrote: Alan W. Irwin wrote: On 2009-12-12 09:44-0500 David Cole wrote: On Fri, Dec 11, 2009 at 10:04 AM, Michael Wild them...@gmail.com wrote: Bummer. What where they THINKING??? (if at all...). It seems to me that M$ just CAN'T get it right. No matter how many times they try, how many good examples are out there, they always manage to seriously screw something up... Come to think of it, they probably were thinking about symlink-attacks... Come on. Let's make a deal: you don't bash Microsoft, Apple or Google here on the CMake mailing list and I won't bash Unix or Linux in any forum, anywhere, ever. OK? Does that sound cool? Absolutely. There used to be another poster here (before he got so-over-the-top that he was removed) that kept making gratuitous attacks on Linux and free software, and that was extremely annoying. So as a Linux developer I support Dave's call to be aware of other's strong feelings and stay on topic so we don't waste a lot of time here. Back on topic I am one of the lead developers of the PLplot CMake-based build system. However, my development experience is Linux only so I must rely on my Windows developer colleagues to catch any Linux-only or Unix-only mistakes I put into our build system. Up to this thread, I had no idea that there wasn't some reliable way to create symlinks on Windows, and it's only by chance that I haven't used create_symlink in any part of our build other than the Linux-only documentation build. Before this thread, I always assumed cmake -E commands gave you an excellent way to do common tasks in a cross-platform way. I appeal to the CMake developers to avoid from now on implementing any more CMake -E commands that have no hope of ever fulfilling that mandate, Also, please deprecate and document the cmake -E commands with obvious cross-platform limitations because otherwise your users are going to assume (like I did) that those commands are the recommended way to help make their project cross-platform. Is create_symlink an isolated case, or are there other cmake -E commands to worry about? Also, is create_symlink really a lost cross-platform cause? Reading later in Dave's post, it appears that the symlink concept does work on some Windows platform (he mentioned something about shortcuts). If there are intentions to make it work on a number of Windows platforms eventually, but that just hasn't happened yet, then _warn_ about that issue (e.g., something like Unix-only for now in the documentation). Also, if the CMake -E command is run on a platform that doesn't support it something better than a silent failure should be the result. Some things just can not be done cross platform. For example reading/ writing the windows registry, creating an OSX application bundle, and sym-links. Also, some computers don't even have shared libraries. Should we disable those features from CMake? That said, the symlink command is the only -E that does not work cross platform. The -E create_symlink does return failure from main when called on windows. So, if you used it in a custom command which is the idea for -E stuff, it would fail in a noticeable way (the build would fail). If you call it from execute_process, you should be checking the return value as well. -Bill Just out of curiosity: how does Cygwin handle this whole symbolic link business? Marcel Loose. ___ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Follow this link to subscribe/unsubscribe: http://www.cmake.org/mailman/listinfo/cmake ___ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Follow this link to subscribe/unsubscribe: http://www.cmake.org/mailman/listinfo/cmake
Re: [CMake] cmake -E create_symlink for Windows
On Mon, 2009-12-14 at 08:23 -0500, Bill Lorensen wrote: http://en.wikipedia.org/wiki/Symbolic_link#Cygwin_symbolic_links OK, that puts us back at square one. Why is it that CMake cannot use Windows shortcuts as an alternative to Unix symbolic links, whereas Cygwin can? Best regards, Marcel Loose. ___ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Follow this link to subscribe/unsubscribe: http://www.cmake.org/mailman/listinfo/cmake
Re: [CMake] cmake -E create_symlink for Windows
On 14. Dec, 2009, at 14:29 , Marcel Loose wrote: On Mon, 2009-12-14 at 08:23 -0500, Bill Lorensen wrote: http://en.wikipedia.org/wiki/Symbolic_link#Cygwin_symbolic_links OK, that puts us back at square one. Why is it that CMake cannot use Windows shortcuts as an alternative to Unix symbolic links, whereas Cygwin can? Best regards, Marcel Loose. Because somebody has to implement it ;-). And then I'm not sure that the tool-chain (i.e. compilers etc.) will be able to handle Windows-shortcuts. Does anybody know, or has visual studio available to try it out, whether e.g. CL.exe and RC.exe can handle Windows-shortcuts? What about MINGW, GnuWin32 and Intel compilers? Michael ___ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Follow this link to subscribe/unsubscribe: http://www.cmake.org/mailman/listinfo/cmake
Re: [CMake] cmake -E create_symlink for Windows
On 14.12.09 14:29:06, Marcel Loose wrote: On Mon, 2009-12-14 at 08:23 -0500, Bill Lorensen wrote: http://en.wikipedia.org/wiki/Symbolic_link#Cygwin_symbolic_links OK, that puts us back at square one. Why is it that CMake cannot use Windows shortcuts as an alternative to Unix symbolic links, whereas Cygwin can? Becaue Cygwin emulates a complete filesystem IIRC (at least inside its bash). The problem is not that cmake could not create a shortcut for the -E create_symlink call, the problem is that very few apps are able to recognize the shortcut as symlink and act accordingly. So it simply doesn't make any sense to create one if it only works when the user double-clicks on it in explorer. Andreas -- Keep it short for pithy sake. ___ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Follow this link to subscribe/unsubscribe: http://www.cmake.org/mailman/listinfo/cmake
Re: [CMake] cmake -E create_symlink for Windows CMake Digest, Vol 68, Issue 51
I think there should be a cross platform command for creating symbolic links, under windows 2000 and above with the ntfs formatted disk. You can create symbolic links to directories with a program called “junction” (Vista has a build-in command) - junction has switches that would simulate the Linux version of ln -s. Of course in Windows it's a real link to the directory and if you delete/copy the files you get the results you would expect – files are deleted or copied – not links. You could get around this by getting a directory listing under windows – which does show junctions – and use the junction program to make the copies. Of course all the file commands in windows would have to check for this property because CMake itself has adopted the Linux version of a file system for its cross-platform commands. The objection that CMake would now have to find and run an external program – doesn't have much weight because cmake does this all the time, It finds the compiler, linker, resource compiler etc. If that is not an acceptable method to implement the command – then a built-in version of junction could be created – In CTest you should take a look at the platform-dependent code to determine if a windows machine can run multi-CPU threads. – a built-in version of symbolic links would not generate any more or obscure platform-dependent code then that test whose only purpose is to fill a form for CDash. As for the problem at hand you could create a MACRO that uses cmake -E under Linux and junction under windows. Samuel E. Henley OSRail.net On Mon, 2009-12-14 at 06:00 -0500, cmake-requ...@cmake.org wrote: Send CMake mailing list submissions to cmake@cmake.org To subscribe or unsubscribe via the World Wide Web, visit http://www.cmake.org/mailman/listinfo/cmake or, via email, send a message with subject or body 'help' to cmake-requ...@cmake.org You can reach the person managing the list at cmake-owne r...@cmake.org When replying, please edit your Subject line so it is more specific than Re: Contents of CMake digest... Today's Topics: 1. Re: Mac OSX GUI (Bill Hoffman) 2. Re: cmake -E create_symlink for Windows (Marcel Loose) 3. Re: Mac OSX GUI (Steven Wilson) 4. Re: Mac OSX GUI (Mike Jackson) 5. Re: cmake -E create_symlink for Windows (Marcel Loose) 6. Re: ADD_CUSTOM_COMMAND (Keyan) 7. How to generate xcodeproj file correctly for Xcode? (DONG Li) Message: 2 Date: Sun, 13 Dec 2009 23:38:18 +0100 From: Marcel Loose lo...@astron.nl Subject: Re: [CMake] cmake -E create_symlink for Windows To: Alan W. Irwin ir...@beluga.phys.uvic.ca Cc: cmake@cmake.org, Michael Wild them...@gmail.com,Bill Hoffman bill.hoff...@kitware.com Message-ID: 1260743898.18575.13.ca...@galadriel Content-Type: text/plain; charset=UTF-8 On Sat, 2009-12-12 at 14:35 -0800, Alan W. Irwin wrote: On 2009-12-12 12:02-0500 Bill Hoffman wrote: Some things just can not be done cross platform. For example reading/ writing the windows registry, creating an OSX application bundle, and sym-links. Also, some computers don't even have shared libraries. Should we disable those features from CMake? That said, the symlink command is the only -E that does not work cross platform. The -E create_symlink does return failure from main when called on windows. So, if you used it in a custom command which is the idea for -E stuff, it would fail in a noticeable way (the build would fail). If you call it from execute_process, you should be checking the return value as well. I guess I am the victim of the assumption that all cmake -E commands are supposed to work cross-platform since all of them do so (which I was glad to hear) other than create_symlink. Right now, here is what cmake -E help says about that command. create_symlink old new- create a symbolic link new - old If you simply added (UNIX ONLY) to that documentation string, then users like me wouldn't make unwarranted assumptions. Alan __ Alan W. Irwin Astronomical research affiliation with Department of Physics and Astronomy, University of Victoria (astrowww.phys.uvic.ca). Programming affiliations with the FreeEOS equation-of-state implementation for stellar interiors (freeeos.sf.net); PLplot scientific plotting software package (plplot.org); the libLASi project (unifont.org/lasi); the Loads of Linux Links project (loll.sf.net); and the Linux Brochure Project (lbproject.sf.net). __ Linux-powered Science __ I second that. I was also under the impression that 'cmake -E' provided a nice abstraction for a number of commands that could be used cross-platform, but with different syntaxes. Seems that create_symlink is the odd one out here. Bummer! The thing is: it's too late when the build fails (on Windows
Re: [CMake] cmake -E create_symlink for Windows
I think it comes down to what error to flag, “You can't use this command on your operation system because we didn't implement it” or “your operation system is obsolete – build a work-around” or “no message at all because it's windows and no one does development with windows”. The last is odd for a cross-platform make/auto tools replacement, but I favor “your system is obsolete” – I least the script writer will know at the first test of his code, to change his code – after all CMake is only a tool. I use the junction program with my continuous and nightly builds – otherwise I would have multiple copy of pre-build third-party libraries or end up requiring the libraries to always be in the same location(Linux). My Linux builds use the links for the same reason. The only problem is when your using the explorer – you don't know it's a link – so I always add batch files to remove or add the links using junction – you could change their folder icon. There is a program to link files but I've never found a use for linking single files. But your right it doesn't work like Linux. Samuel E. Henley OSRail.net ___ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Follow this link to subscribe/unsubscribe: http://www.cmake.org/mailman/listinfo/cmake
Re: [CMake] cmake -E create_symlink for Windows
On Sat, 2009-12-12 at 14:35 -0800, Alan W. Irwin wrote: On 2009-12-12 12:02-0500 Bill Hoffman wrote: Some things just can not be done cross platform. For example reading/ writing the windows registry, creating an OSX application bundle, and sym-links. Also, some computers don't even have shared libraries. Should we disable those features from CMake? That said, the symlink command is the only -E that does not work cross platform. The -E create_symlink does return failure from main when called on windows. So, if you used it in a custom command which is the idea for -E stuff, it would fail in a noticeable way (the build would fail). If you call it from execute_process, you should be checking the return value as well. I guess I am the victim of the assumption that all cmake -E commands are supposed to work cross-platform since all of them do so (which I was glad to hear) other than create_symlink. Right now, here is what cmake -E help says about that command. create_symlink old new- create a symbolic link new - old If you simply added (UNIX ONLY) to that documentation string, then users like me wouldn't make unwarranted assumptions. Alan __ Alan W. Irwin Astronomical research affiliation with Department of Physics and Astronomy, University of Victoria (astrowww.phys.uvic.ca). Programming affiliations with the FreeEOS equation-of-state implementation for stellar interiors (freeeos.sf.net); PLplot scientific plotting software package (plplot.org); the libLASi project (unifont.org/lasi); the Loads of Linux Links project (loll.sf.net); and the Linux Brochure Project (lbproject.sf.net). __ Linux-powered Science __ I second that. I was also under the impression that 'cmake -E' provided a nice abstraction for a number of commands that could be used cross-platform, but with different syntaxes. Seems that create_symlink is the odd one out here. Bummer! The thing is: it's too late when the build fails (on Windows), because long before then, I, as a developer of the build environment, decided to use the presumed cross-platform command create_symlink, only to find out much later that it doesn't work on Windows. Best regards, Marcel Loose. ___ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Follow this link to subscribe/unsubscribe: http://www.cmake.org/mailman/listinfo/cmake
Re: [CMake] cmake -E create_symlink for Windows
On Fri, Dec 11, 2009 at 10:04 AM, Michael Wild them...@gmail.com wrote: Bummer. What where they THINKING??? (if at all...). It seems to me that M$ just CAN'T get it right. No matter how many times they try, how many good examples are out there, they always manage to seriously screw something up... Come to think of it, they probably were thinking about symlink-attacks... Come on. Let's make a deal: you don't bash Microsoft, Apple or Google here on the CMake mailing list and I won't bash Unix or Linux in any forum, anywhere, ever. OK? Does that sound cool? The fact is that Microsoft introduced shortcuts in Windows 95 and Apple had aliases on Mac OS even before that... and they are both conceptually equivalent to symlinks. symlinks are a *convenience* feature... but they are not supported everywhere universally. So write the code that uses them if they are there, but has an alternate strategy if they're not available. But don't blame Microsoft... Maybe you should ask yourself why you're even bothering to write software for Windows if it's so bad. :-) David ___ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Follow this link to subscribe/unsubscribe: http://www.cmake.org/mailman/listinfo/cmake
Re: [CMake] cmake -E create_symlink for Windows
On 2009-12-12 09:44-0500 David Cole wrote: On Fri, Dec 11, 2009 at 10:04 AM, Michael Wild them...@gmail.com wrote: Bummer. What where they THINKING??? (if at all...). It seems to me that M$ just CAN'T get it right. No matter how many times they try, how many good examples are out there, they always manage to seriously screw something up... Come to think of it, they probably were thinking about symlink-attacks... Come on. Let's make a deal: you don't bash Microsoft, Apple or Google here on the CMake mailing list and I won't bash Unix or Linux in any forum, anywhere, ever. OK? Does that sound cool? Absolutely. There used to be another poster here (before he got so-over-the-top that he was removed) that kept making gratuitous attacks on Linux and free software, and that was extremely annoying. So as a Linux developer I support Dave's call to be aware of other's strong feelings and stay on topic so we don't waste a lot of time here. Back on topic I am one of the lead developers of the PLplot CMake-based build system. However, my development experience is Linux only so I must rely on my Windows developer colleagues to catch any Linux-only or Unix-only mistakes I put into our build system. Up to this thread, I had no idea that there wasn't some reliable way to create symlinks on Windows, and it's only by chance that I haven't used create_symlink in any part of our build other than the Linux-only documentation build. Before this thread, I always assumed cmake -E commands gave you an excellent way to do common tasks in a cross-platform way. I appeal to the CMake developers to avoid from now on implementing any more CMake -E commands that have no hope of ever fulfilling that mandate, Also, please deprecate and document the cmake -E commands with obvious cross-platform limitations because otherwise your users are going to assume (like I did) that those commands are the recommended way to help make their project cross-platform. Is create_symlink an isolated case, or are there other cmake -E commands to worry about? Also, is create_symlink really a lost cross-platform cause? Reading later in Dave's post, it appears that the symlink concept does work on some Windows platform (he mentioned something about shortcuts). If there are intentions to make it work on a number of Windows platforms eventually, but that just hasn't happened yet, then _warn_ about that issue (e.g., something like Unix-only for now in the documentation). Also, if the CMake -E command is run on a platform that doesn't support it something better than a silent failure should be the result. Alan __ Alan W. Irwin Astronomical research affiliation with Department of Physics and Astronomy, University of Victoria (astrowww.phys.uvic.ca). Programming affiliations with the FreeEOS equation-of-state implementation for stellar interiors (freeeos.sf.net); PLplot scientific plotting software package (plplot.org); the libLASi project (unifont.org/lasi); the Loads of Linux Links project (loll.sf.net); and the Linux Brochure Project (lbproject.sf.net). __ Linux-powered Science __ ___ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Follow this link to subscribe/unsubscribe: http://www.cmake.org/mailman/listinfo/cmake
Re: [CMake] cmake -E create_symlink for Windows
Alan W. Irwin wrote: On 2009-12-12 09:44-0500 David Cole wrote: On Fri, Dec 11, 2009 at 10:04 AM, Michael Wild them...@gmail.com wrote: Bummer. What where they THINKING??? (if at all...). It seems to me that M$ just CAN'T get it right. No matter how many times they try, how many good examples are out there, they always manage to seriously screw something up... Come to think of it, they probably were thinking about symlink-attacks... Come on. Let's make a deal: you don't bash Microsoft, Apple or Google here on the CMake mailing list and I won't bash Unix or Linux in any forum, anywhere, ever. OK? Does that sound cool? Absolutely. There used to be another poster here (before he got so-over-the-top that he was removed) that kept making gratuitous attacks on Linux and free software, and that was extremely annoying. So as a Linux developer I support Dave's call to be aware of other's strong feelings and stay on topic so we don't waste a lot of time here. Back on topic I am one of the lead developers of the PLplot CMake-based build system. However, my development experience is Linux only so I must rely on my Windows developer colleagues to catch any Linux-only or Unix-only mistakes I put into our build system. Up to this thread, I had no idea that there wasn't some reliable way to create symlinks on Windows, and it's only by chance that I haven't used create_symlink in any part of our build other than the Linux-only documentation build. Before this thread, I always assumed cmake -E commands gave you an excellent way to do common tasks in a cross-platform way. I appeal to the CMake developers to avoid from now on implementing any more CMake -E commands that have no hope of ever fulfilling that mandate, Also, please deprecate and document the cmake -E commands with obvious cross-platform limitations because otherwise your users are going to assume (like I did) that those commands are the recommended way to help make their project cross-platform. Is create_symlink an isolated case, or are there other cmake -E commands to worry about? Also, is create_symlink really a lost cross-platform cause? Reading later in Dave's post, it appears that the symlink concept does work on some Windows platform (he mentioned something about shortcuts). If there are intentions to make it work on a number of Windows platforms eventually, but that just hasn't happened yet, then _warn_ about that issue (e.g., something like Unix-only for now in the documentation). Also, if the CMake -E command is run on a platform that doesn't support it something better than a silent failure should be the result. Some things just can not be done cross platform. For example reading/ writing the windows registry, creating an OSX application bundle, and sym-links. Also, some computers don't even have shared libraries. Should we disable those features from CMake? That said, the symlink command is the only -E that does not work cross platform. The -E create_symlink does return failure from main when called on windows. So, if you used it in a custom command which is the idea for -E stuff, it would fail in a noticeable way (the build would fail). If you call it from execute_process, you should be checking the return value as well. -Bill ___ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Follow this link to subscribe/unsubscribe: http://www.cmake.org/mailman/listinfo/cmake
Re: [CMake] cmake -E create_symlink for Windows
On 12. Dec, 2009, at 17:42 , Alan W. Irwin wrote: On 2009-12-12 09:44-0500 David Cole wrote: On Fri, Dec 11, 2009 at 10:04 AM, Michael Wild them...@gmail.com wrote: Bummer. What where they THINKING??? (if at all...). It seems to me that M$ just CAN'T get it right. No matter how many times they try, how many good examples are out there, they always manage to seriously screw something up... Come to think of it, they probably were thinking about symlink-attacks... Come on. Let's make a deal: you don't bash Microsoft, Apple or Google here on the CMake mailing list and I won't bash Unix or Linux in any forum, anywhere, ever. OK? Does that sound cool? I beg your pardon?! I think just a little exasperation is in place here, especially I couldn't find any documentation on this apart from the page mentioned by Hendrik. What had me really surprised is the fact that http://msdn.microsoft.com/en-us/library/aa363866(VS.85).aspx doesn't say a word on the fact that the function will fail if the executing process doesn't have the SeCreateSymbolic right. My wording may have been a bit crude, for this I apologize. And I did mention a good reason for having this stringent policy (i.e. symlink attacks). Besides, if you feel like expressing your displeasure with Linux and Unix, please go ahead. After all, if nobody ever does so, how do you expect things to improve in the first place? And referring to the Windows shortcuts: No, they are not equivalent, as they require special treatment and parsing. They are only work-alikes from the user point-of-view when he's interacting with them in the Explorer, or other software that implements the protocol. They are NOT transparent in the sense that if you write a piece of software that reads and writes to files, you don't have to care whether this actually is a shortcut or not. Absolutely. There used to be another poster here (before he got so-over-the-top that he was removed) that kept making gratuitous attacks on Linux and free software, and that was extremely annoying. So as a Linux developer I support Dave's call to be aware of other's strong feelings and stay on topic so we don't waste a lot of time here. As I mentioned, I only expressed my disappointment that it won't be possible to implement -E create_symlink in any useful way on Windows, so yes, IMHO it was on topic. The waste of time comes into play if somebody spends considerable effort developing a build system using -E create_symlink on a non-Windows platform and then has to refactor the whole thing because he based the whole thing on wrong assumptions (refer to your post below). [...] Before this thread, I always assumed cmake -E commands gave you an excellent way to do common tasks in a cross-platform way. I appeal to the CMake developers to avoid from now on implementing any more CMake -E commands that have no hope of ever fulfilling that mandate, Also, please deprecate and document the cmake -E commands with obvious cross-platform limitations because otherwise your users are going to assume (like I did) that those commands are the recommended way to help make their project cross-platform. Is create_symlink an isolated case, or are there other cmake -E commands to worry about? I don't think it should be deprecated or removed, just for the simple reason that there is a lot of Unix-only software using CMake that can really profit from it. This also applies to other platform peculiarities. However, what definitely needs to be done, is to state the supported platforms very clearly in the documentation. Also, is create_symlink really a lost cross-platform cause? Reading later in Dave's post, it appears that the symlink concept does work on some Windows platform (he mentioned something about shortcuts). If there are intentions to make it work on a number of Windows platforms eventually, but that just hasn't happened yet, then _warn_ about that issue (e.g., something like Unix-only for now in the documentation). Also, if the CMake -E command is run on a platform that doesn't support it something better than a silent failure should be the result. As I said, shortcuts are only poor man's substitutes for symlinks. Essentially, they are files with a .lnk extension that contain the shortcut destination. In as such they are not THAT different from most symlink implementations. The difference is, that they are not part of the file system and that the programmer needs to deal with them manually. Refer to http://msdn.microsoft.com/en-us/library/bb776891(VS.85).aspx to get an impression of how tedious that is. Again, I'm sorry if I offended any of you, that was not my intention. But I also hope that you understand some of my exasperation. Michael ___ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and
Re: [CMake] cmake -E create_symlink for Windows
On 2009-12-12 12:02-0500 Bill Hoffman wrote: Some things just can not be done cross platform. For example reading/ writing the windows registry, creating an OSX application bundle, and sym-links. Also, some computers don't even have shared libraries. Should we disable those features from CMake? That said, the symlink command is the only -E that does not work cross platform. The -E create_symlink does return failure from main when called on windows. So, if you used it in a custom command which is the idea for -E stuff, it would fail in a noticeable way (the build would fail). If you call it from execute_process, you should be checking the return value as well. I guess I am the victim of the assumption that all cmake -E commands are supposed to work cross-platform since all of them do so (which I was glad to hear) other than create_symlink. Right now, here is what cmake -E help says about that command. create_symlink old new- create a symbolic link new - old If you simply added (UNIX ONLY) to that documentation string, then users like me wouldn't make unwarranted assumptions. Alan __ Alan W. Irwin Astronomical research affiliation with Department of Physics and Astronomy, University of Victoria (astrowww.phys.uvic.ca). Programming affiliations with the FreeEOS equation-of-state implementation for stellar interiors (freeeos.sf.net); PLplot scientific plotting software package (plplot.org); the libLASi project (unifont.org/lasi); the Loads of Linux Links project (loll.sf.net); and the Linux Brochure Project (lbproject.sf.net). __ Linux-powered Science __ ___ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Follow this link to subscribe/unsubscribe: http://www.cmake.org/mailman/listinfo/cmake
[CMake] cmake -E create_symlink for Windows
Hi all, I was browsing the CMake sources for a problem I was facing with the creation of symlinks (on Unix that is) and I noticed that the SystemTools::CreateSymlink function simply returns false when building on a Windows platform. Does that mean that I cannot use 'cmake -E create_symlink' on Windows. If that's the case I consider it a bug, because the documentation suggests that 'cmake -E create_symlink' provides a platform independent way of creating symbolic links. So, if the OS and/or filesystem does not support symbolic links, IMHO, it should just copy the file. Best regards, Marcel Loose. ___ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Follow this link to subscribe/unsubscribe: http://www.cmake.org/mailman/listinfo/cmake
Re: [CMake] cmake -E create_symlink for Windows
On 11. Dec, 2009, at 14:27 , Marcel Loose wrote: Hi all, I was browsing the CMake sources for a problem I was facing with the creation of symlinks (on Unix that is) and I noticed that the SystemTools::CreateSymlink function simply returns false when building on a Windows platform. Does that mean that I cannot use 'cmake -E create_symlink' on Windows. If that's the case I consider it a bug, because the documentation suggests that 'cmake -E create_symlink' provides a platform independent way of creating symbolic links. So, if the OS and/or filesystem does not support symbolic links, IMHO, it should just copy the file. Best regards, Marcel Loose. Simply copying the file might be just as bad if people assume it really IS a symlink... IMHO, if the OS can't create a symlink, cmake -E create_symlink should fail loudly, not just silently ignore it. And somebody should implement this function for Windows = Vista/2008 (i.e. WINVER = 0x0600): http://msdn.microsoft.com/en-us/library/aa363866(VS.85).aspx Michael ___ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Follow this link to subscribe/unsubscribe: http://www.cmake.org/mailman/listinfo/cmake
Re: [CMake] cmake -E create_symlink for Windows
On Fri, 2009-12-11 at 14:51 +0100, Michael Wild wrote: On 11. Dec, 2009, at 14:27 , Marcel Loose wrote: Hi all, I was browsing the CMake sources for a problem I was facing with the creation of symlinks (on Unix that is) and I noticed that the SystemTools::CreateSymlink function simply returns false when building on a Windows platform. Does that mean that I cannot use 'cmake -E create_symlink' on Windows. If that's the case I consider it a bug, because the documentation suggests that 'cmake -E create_symlink' provides a platform independent way of creating symbolic links. So, if the OS and/or filesystem does not support symbolic links, IMHO, it should just copy the file. Best regards, Marcel Loose. Simply copying the file might be just as bad if people assume it really IS a symlink... IMHO, if the OS can't create a symlink, cmake -E create_symlink should fail loudly, not just silently ignore it. And somebody should implement this function for Windows = Vista/2008 (i.e. WINVER = 0x0600): http://msdn.microsoft.com/en-us/library/aa363866(VS.85).aspx Michael Hi Michael, I think it depends. Failing loudly may not always be desirable, just as failing silently. In my particular case, I was just creating a bunch of symlinks to directories; no need to discern these symlinks from the actual directories, but I need to be able to access the directory contents. When it comes to symlinks to files, there may be situations where you would really like it to be a link, e.g. when editing the file. Would that be a CMake usage scenario?? I don't know what's the best way to deal with this issue. What do the CMake developers think of this? Best regards, Marcel Loose. ___ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Follow this link to subscribe/unsubscribe: http://www.cmake.org/mailman/listinfo/cmake
Re: [CMake] cmake -E create_symlink for Windows
Zitat von Michael Wild them...@gmail.com: On 11. Dec, 2009, at 14:27 , Marcel Loose wrote: I was browsing the CMake sources for a problem I was facing with the creation of symlinks (on Unix that is) and I noticed that the SystemTools::CreateSymlink function simply returns false when building on a Windows platform. Does that mean that I cannot use 'cmake -E create_symlink' on Windows. If that's the case I consider it a bug, because the documentation suggests that 'cmake -E create_symlink' provides a platform independent way of creating symbolic links. So, if the OS and/or filesystem does not support symbolic links, IMHO, it should just copy the file. Simply copying the file might be just as bad if people assume it really IS a symlink... IMHO, if the OS can't create a symlink, cmake -E create_symlink should fail loudly, not just silently ignore it. And somebody should implement this function for Windows = Vista/2008 (i.e. WINVER = 0x0600): http://msdn.microsoft.com/en-us/library/aa363866(VS.85).aspx For this, also see http://schinagl.priv.at/nt/hardlinkshellext/hardlinkshellext.html Please note the UAC dialog when creating symlink on Vista. Have fun, I'd say :-( And what do you do on WindowsXP? What to do on FAT filesystems? Additionally, without that extension above, it is non-obvious for Windows users that a specific file is a symbolic link. HS ___ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Follow this link to subscribe/unsubscribe: http://www.cmake.org/mailman/listinfo/cmake
Re: [CMake] cmake -E create_symlink for Windows
Zitat von Michael Wild them...@gmail.com: On 11. Dec, 2009, at 15:17 , Hendrik Sattler wrote: Zitat von Michael Wild them...@gmail.com: On 11. Dec, 2009, at 14:27 , Marcel Loose wrote: I was browsing the CMake sources for a problem I was facing with the creation of symlinks (on Unix that is) and I noticed that the SystemTools::CreateSymlink function simply returns false when building on a Windows platform. Does that mean that I cannot use 'cmake -E create_symlink' on Windows. If that's the case I consider it a bug, because the documentation suggests that 'cmake -E create_symlink' provides a platform independent way of creating symbolic links. So, if the OS and/or filesystem does not support symbolic links, IMHO, it should just copy the file. Simply copying the file might be just as bad if people assume it really IS a symlink... IMHO, if the OS can't create a symlink, cmake -E create_symlink should fail loudly, not just silently ignore it. And somebody should implement this function for Windows = Vista/2008 (i.e. WINVER = 0x0600): http://msdn.microsoft.com/en-us/library/aa363866(VS.85).aspx For this, also see http://schinagl.priv.at/nt/hardlinkshellext/hardlinkshellext.html Please note the UAC dialog when creating symlink on Vista. Have fun, I'd say :-( And what do you do on WindowsXP? What to do on FAT filesystems? Additionally, without that extension above, it is non-obvious for Windows users that a specific file is a symbolic link. The UAC-thing only applies to directories where the user has no write-acces (including the admin), right? So if you're half-way sane, and build in a user-owned directory, you should be UAC-free... To cite from that page: Vista and UAC One of the major Vista changes was the so called User Account Control (UAC). Due to UAC some API calls need elevation to administrative level, and this elevation must be acknowledged via the below shown dialog box. Unfortunately, and I still can't believe this, the API call CreateSymbolicLink is a call, which needs elevation, and thus causes this annoying dialog box come up every time a symbolic link is created. So, no, every time, even on own directories. I don't currently use Vista or Windows7, though. Also read the rest of that part of the page: cmake should not use functions directly that need elevation. HS PS: added list back ___ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Follow this link to subscribe/unsubscribe: http://www.cmake.org/mailman/listinfo/cmake
Re: [CMake] cmake -E create_symlink for Windows
On Fri, Dec 11, 2009 at 9:18 AM, Marcel Loose lo...@astron.nl wrote: On Fri, 2009-12-11 at 14:51 +0100, Michael Wild wrote: On 11. Dec, 2009, at 14:27 , Marcel Loose wrote: Hi all, I was browsing the CMake sources for a problem I was facing with the creation of symlinks (on Unix that is) and I noticed that the SystemTools::CreateSymlink function simply returns false when building on a Windows platform. Does that mean that I cannot use 'cmake -E create_symlink' on Windows. If that's the case I consider it a bug, because the documentation suggests that 'cmake -E create_symlink' provides a platform independent way of creating symbolic links. So, if the OS and/or filesystem does not support symbolic links, IMHO, it should just copy the file. Best regards, Marcel Loose. Simply copying the file might be just as bad if people assume it really IS a symlink... IMHO, if the OS can't create a symlink, cmake -E create_symlink should fail loudly, not just silently ignore it. And somebody should implement this function for Windows = Vista/2008 (i.e. WINVER = 0x0600): http://msdn.microsoft.com/en-us/library/aa363866(VS.85).aspx Michael Hi Michael, I think it depends. Failing loudly may not always be desirable, just as failing silently. In my particular case, I was just creating a bunch of symlinks to directories; no need to discern these symlinks from the actual directories, but I need to be able to access the directory contents. When it comes to symlinks to files, there may be situations where you would really like it to be a link, e.g. when editing the file. Would that be a CMake usage scenario?? I don't know what's the best way to deal with this issue. What do the CMake developers think of this? I can't speak for the rest of the CMake developers, but personally, I just simply avoid symlinks at all costs in projects that are meant to be cross-platform. If I'm working on a Mac-or-Linux-only project, symlinks can sometimes be useful... but they are simply not useful on Windows. Just my opinion, David ___ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Follow this link to subscribe/unsubscribe: http://www.cmake.org/mailman/listinfo/cmake
Re: [CMake] cmake -E create_symlink for Windows
On 11. Dec, 2009, at 15:35 , Hendrik Sattler wrote: Zitat von Michael Wild them...@gmail.com: On 11. Dec, 2009, at 15:17 , Hendrik Sattler wrote: Zitat von Michael Wild them...@gmail.com: On 11. Dec, 2009, at 14:27 , Marcel Loose wrote: I was browsing the CMake sources for a problem I was facing with the creation of symlinks (on Unix that is) and I noticed that the SystemTools::CreateSymlink function simply returns false when building on a Windows platform. Does that mean that I cannot use 'cmake -E create_symlink' on Windows. If that's the case I consider it a bug, because the documentation suggests that 'cmake -E create_symlink' provides a platform independent way of creating symbolic links. So, if the OS and/or filesystem does not support symbolic links, IMHO, it should just copy the file. Simply copying the file might be just as bad if people assume it really IS a symlink... IMHO, if the OS can't create a symlink, cmake -E create_symlink should fail loudly, not just silently ignore it. And somebody should implement this function for Windows = Vista/2008 (i.e. WINVER = 0x0600): http://msdn.microsoft.com/en-us/library/aa363866(VS.85).aspx For this, also see http://schinagl.priv.at/nt/hardlinkshellext/hardlinkshellext.html Please note the UAC dialog when creating symlink on Vista. Have fun, I'd say :-( And what do you do on WindowsXP? What to do on FAT filesystems? Additionally, without that extension above, it is non-obvious for Windows users that a specific file is a symbolic link. The UAC-thing only applies to directories where the user has no write-acces (including the admin), right? So if you're half-way sane, and build in a user-owned directory, you should be UAC-free... To cite from that page: Vista and UAC One of the major Vista changes was the so called User Account Control (UAC). Due to UAC some API calls need elevation to administrative level, and this elevation must be acknowledged via the below shown dialog box. Unfortunately, and I still can't believe this, the API call CreateSymbolicLink is a call, which needs elevation, and thus causes this annoying dialog box come up every time a symbolic link is created. Bummer. What where they THINKING??? (if at all...). It seems to me that M$ just CAN'T get it right. No matter how many times they try, how many good examples are out there, they always manage to seriously screw something up... Come to think of it, they probably were thinking about symlink-attacks... So, no, every time, even on own directories. I don't currently use Vista or Windows7, though. Also read the rest of that part of the page: cmake should not use functions directly that need elevation. Agreed, but then creating symlinks will be just plain impossible on Windows... For the general interest: somebody did it for 4msysgit. http://repo.or.cz/w/git/mingw/4msysgit.git/commitdiff/043a43e7ec1ca4aa492406f438d89e1f35df127a Michael ___ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Follow this link to subscribe/unsubscribe: http://www.cmake.org/mailman/listinfo/cmake
