May 2010 - Darwin-dev - lists.apple.com

Re: Using SystemConfiguration API inside KEXT
by John B Brown 11 May '10

11 May '10

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com User-agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.1.7) Gecko/20100111 Thunderbird/3.0.1 Dear Amanda, We're not comparing seniority, last I checked (though several of us go much farther back than that). You asked a question, you got an answer, and you didn't like the answer. Puffing up your ego and whining about the platform you're asking for help about is not going to help. So, to get back to your original question: SystemConfiguration is a userland API, not a kernel API, and is not available to kernel extensions. Nor does the Darwin kernel have a concept of a "primary" interface (something it shares with most UNIX and UNIX-like kernels). What are you trying to implement? Perhaps with a description of your goal, some of us could make some suggestions about how you can accomplish what you need. --Amanda Shalom, John B. Brown. [jbb(a)vcn.com] 358 High Street, Buffalo, Wyoming 82834 "Freedom is not worth having if it does not include the freedom to make mistakes" Mahatma Gandhi "If any question why we died, tell them, because our fathers lied." Rudyard Kipling "A man who does not know the truth is just an idiot but a man who knows the truth and calls it a lie is a crook." Bertolt Brecht "I wonder whether the world is being run by smart people who are putting us on or by imbeciles who really mean it." Mark Twain _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… Somehow you think I asked a question about SystemConfiguration; I did no such thing. I suggested the include call would not work as written. I was wrong in fact, if not in principle. On 5/11/10 5:09 PM, Amanda Walker wrote: On May 11, 2010, at 5:31 PM, John B Brown wrote: Thank you. My last instruction in C was on a VAX, and your discourse is most illuminating. The other systems were AT&T 3B1 and 3B2 surplus that I took care of at school. That should date me pretty well. This email sent to site_archiver(a)lists.apple.com

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Re: Using SystemConfiguration API inside KEXT
by John B Brown 11 May '10

11 May '10

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com User-agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.1.7) Gecko/20100111 Thunderbird/3.0.1 Dear Jens, Right, my copy of H&S is 1991. Shalom, John B. Brown. [jbb(a)vcn.com] 358 High Street, Buffalo, Wyoming 82834 "Freedom is not worth having if it does not include the freedom to make mistakes" Mahatma Gandhi "If any question why we died, tell them, because our fathers lied." Rudyard Kipling "A man who does not know the truth is just an idiot but a man who knows the truth and calls it a lie is a crook." Bertolt Brecht "I wonder whether the world is being run by smart people who are putting us on or by imbeciles who really mean it." Mark Twain On May 11, 2010, at 2:45 PM, John B Brown wrote: What you are describing does not appear to be either ANSI or traditional C, unless I misunderstand Harbison and Steele. K&R and ANSI C ran on plenty of operating systems that had no /usr/include directory and didn't even use forward slashes as directory separators, including VMS, CP/M, DOS, MS Windows and the 'classic' Mac OS. So I really don't think you have any ground to claim that the traditional Unix include path is somehow baked into any C standard. In any case, not that it makes any difference to this argument, but it's true that the ISO spec Jamison was quoting from is newer than ANSI C. You might want to invest in a newer copy of H&S. Things have moved on a bit since the original ANSI C standard was ratified in 1989 — C99 has some very useful features, not to mention the (!!nonstandard!!) extensions found in GCC. ;-) _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… On 5/11/10 4:00 PM, Jens Alfke wrote: —Jens This email sent to site_archiver(a)lists.apple.com

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Re: Using SystemConfiguration API inside KEXT
by Amanda Walker 11 May '10

11 May '10

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com On May 11, 2010, at 7:16 PM, Ben Greenfield wrote: > John didn't ask the original question he was trying to help some innocent bystander. I stand corrected! Sorry about that. So, Andy: what is it you're trying to do? --Amanda _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… This email sent to site_archiver(a)lists.apple.com

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Re: Using SystemConfiguration API inside KEXT
by Ben Greenfield 11 May '10

11 May '10

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Let's all take a deep breath before things get going again. On May 11, 2010, at 7:09 PM, Amanda Walker wrote: > On May 11, 2010, at 5:31 PM, John B Brown wrote: >> Thank you. My last instruction in C was on a VAX, and your discourse is most illuminating. The other systems were AT&T 3B1 and 3B2 surplus that I took care of at school. That should date me pretty well. > > We're not comparing seniority, last I checked (though several of us go much farther back than that). You asked a question, you got an answer, and you didn't like the answer. Puffing up your ego and whining about the platform you're asking for help about is not going to help. John didn't ask the original question he was trying to help some innocent bystander. _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… This email sent to site_archiver(a)lists.apple.com

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Re: Using SystemConfiguration API inside KEXT
by Amanda Walker 11 May '10

11 May '10

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com On May 11, 2010, at 5:45 PM, John B Brown wrote: > What you are describing does not appear to be either ANSI or traditional C, unless I misunderstand Harbison and Steele. It is ANSI C. Include search paths are (and have always been) implementation dependent. --Amanda _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… This email sent to site_archiver(a)lists.apple.com

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Re: Using SystemConfiguration API inside KEXT
by Amanda Walker 11 May '10

11 May '10

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com On May 11, 2010, at 5:31 PM, John B Brown wrote: > Thank you. My last instruction in C was on a VAX, and your discourse is most illuminating. The other systems were AT&T 3B1 and 3B2 surplus that I took care of at school. That should date me pretty well. We're not comparing seniority, last I checked (though several of us go much farther back than that). You asked a question, you got an answer, and you didn't like the answer. Puffing up your ego and whining about the platform you're asking for help about is not going to help. So, to get back to your original question: SystemConfiguration is a userland API, not a kernel API, and is not available to kernel extensions. Nor does the Darwin kernel have a concept of a "primary" interface (something it shares with most UNIX and UNIX-like kernels). What are you trying to implement? Perhaps with a description of your goal, some of us could make some suggestions about how you can accomplish what you need. --Amanda _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… This email sent to site_archiver(a)lists.apple.com

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Re: Using SystemConfiguration API inside KEXT
by Jens Alfke 11 May '10

11 May '10

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com On May 11, 2010, at 2:45 PM, John B Brown wrote: —Jens _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… What you are describing does not appear to be either ANSI or traditional C, unless I misunderstand Harbison and Steele. K&R and ANSI C ran on plenty of operating systems that had no /usr/ include directory and didn't even use forward slashes as directory separators, including VMS, CP/M, DOS, MS Windows and the 'classic' Mac OS. So I really don't think you have any ground to claim that the traditional Unix include path is somehow baked into any C standard. In any case, not that it makes any difference to this argument, but it's true that the ISO spec Jamison was quoting from is newer than ANSI C. You might want to invest in a newer copy of H&S. Things have moved on a bit since the original ANSI C standard was ratified in 1989 — C99 has some very useful features, not to mention the (!! nonstandard!!) extensions found in GCC. ;-) This email sent to site_archiver(a)lists.apple.com

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Open Source Release: Developer Tools for Xcode 3.2.2
by William Siegrist 11 May '10

11 May '10

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com The Darwin team is pleased to announce the release of source code corresponding to the Developer Tools in Xcode 3.2.2. http://opensource.apple.com/release/developer-tools-322/ Thank you, William Siegrist Darwin Team Apple Inc. _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… This email sent to site_archiver(a)lists.apple.com

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Re: Using SystemConfiguration API inside KEXT
by John B Brown 11 May '10

11 May '10

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com User-agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.1.7) Gecko/20100111 Thunderbird/3.0.1 Dear Jamison, Thank you. That is about as concise an explanation as I've seen so far. Shalom, John B. Brown. [jbb(a)vcn.com] 358 High Street, Buffalo, Wyoming 82834 "Freedom is not worth having if it does not include the freedom to make mistakes" Mahatma Gandhi "If any question why we died, tell them, because our fathers lied." Rudyard Kipling "A man who does not know the truth is just an idiot but a man who knows the truth and calls it a lie is a crook." Bertolt Brecht "I wonder whether the world is being run by smart people who are putting us on or by imbeciles who really mean it." Mark Twain On May 11, 2010, at 4:36 PM, John B Brown wrote: As you say, a decidedly non-portable framework (SystemConfiguration) even an Apple proprietary form, but the call as listed in the original note, <SystemConfiguration/SystemConfiguration.h>, looks like classic C language. Ie. look under the include tree. I suggested there was no way that call could produce the header because the file did not exist as the include call described. It got out of hand because the classic C language #include, according to my reading of the replies, apparently does not work in the Apple compile system. Or maybe it does. I looked at the referenced manual pages and still could not find anything to meet the original call. Well actually, according to the C language spec: "A preprocessing directive of the form #include <h-char-sequence> new-line searches a sequence of implementation-deﬁned places for a header identiﬁed uniquely by the speciﬁed sequence between the<and>delimiters, and causes the replacement of that directive bythe entire contents of the header." -- http://www.open-std.org/JTC1/SC22/WG14/www/docs/n1256.pdf So, <SystemConfiguration/SystemConfiguration.h> just needs to uniquely identify a file. The spec doesn't say anything about slashes necessarily being interpreted as path directory delimiters. GCC (and Clang) on Mac OS X does treat it as a relative path, and will find <sys/cdefs.h> at /usr/include/sys/cdefs.h, but it also knows how to find headers inside of frameworks, in which case <Foo/Bar.h> translates to Foo.framework/Headers/Bar.h. I'm not sure which takes precedence (i.e. what if there's also a /usr/include/Foo/Bar.h). Anyway, the key phrase in the C specification is "implementation-defined". "#include <SystemConfiguration/SystemConfiguration.h>" *is* Standard C. -- Jamison Hope The PTR Group www.theptrgroup.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… What you are describing does not appear to be either ANSI or traditional C, unless I misunderstand Harbison and Steele. On 5/11/10 3:20 PM, Jamison Hope wrote: This email sent to site_archiver(a)lists.apple.com

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Re: Using SystemConfiguration API inside KEXT
by John B Brown 11 May '10

11 May '10

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com User-agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.1.7) Gecko/20100111 Thunderbird/3.0.1 Dear Mo, Shalom, John B. Brown. [jbb(a)vcn.com] 358 High Street, Buffalo, Wyoming 82834 "Freedom is not worth having if it does not include the freedom to make mistakes" Mahatma Gandhi "If any question why we died, tell them, because our fathers lied." Rudyard Kipling "A man who does not know the truth is just an idiot but a man who knows the truth and calls it a lie is a crook." Bertolt Brecht "I wonder whether the world is being run by smart people who are putting us on or by imbeciles who really mean it." Mark Twain On 11-May-2010, at 21:36, John B Brown wrote: Dear Kevin, Correct. No name calling. Technical questions. As you say, a decidedly non-portable framework (SystemConfiguration) even an Apple proprietary form, but the call as listed in the original note,<SystemConfiguration/SystemConfiguration.h>, looks like classic C language. Ie. look under the include tree. I suggested there was no way that call could produce the header because the file did not exist as the include call described. #include works entirely as normal with respect to headers which ARE found in the include path, just as any other C compiler would. however, GCC, when targeted at *-*-darwin* will ALSO search frameworks in the manner described by both the Apple and GCC project web/manual pages. The code for this is part of mainline GCC, but is only enabled on Darwin. It’s been around forever, though — thinking about it, there’s a good chance it pre-dates the existence of Linux. You are assuming that because there is no /usr/include/SystemConfiguration/SystemConfiguration.h then #include does not work as normal, when in fact it does, if the requested header file exists in the include path. That is, #include<stdio.h> will look for (by default, and amongst other places) /usr/include/stdio.h. Mac OS X uses the GCC “-isysroot” compiler switch to target different SDKs for different operating system versions (this option is also a mainline part of GCC). If you are compiling some software targeted at generic Unix systems and have the Developer Tools appropriately installed, then you need to concern yourself with anything Mac OS X-specific: it is a SuSv3-compliant operating system and behaves according to the specifications as any other certified Unix system does. Personally, I regularly build stuff on Mac OS X in tandem with both Linux and OpenSolaris with no modifications between platforms required at all (and only one of those is actually certified Unix right now…) What you think of as “classical C” doesn’t actually specify a whole lot in this regard. Sure, there are conventions, but vendors of both operating systems and compilers are free to adhere or not adhere to them, and in general almost always implemented some differences of a sort or other. I’m honestly not sure where you get the idea of Glibc being a prerequisite for any of this, but, y’know… to each their own. (I’m just going to get this off my chest the once — feel free to disregard it if you wish: nothing in the above wasn’t pointed out to you from the outset — there are a lot of very experienced Mac developers on this list[0], including several who work for Apple; when several members of the list suggest that you’re incorrect, it’s probably best to stop and take stock rather than decrying everyone else as being wrong…) M. _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… Thank you. My last instruction in C was on a VAX, and your discourse is most illuminating. The other systems were AT&T 3B1 and 3B2 surplus that I took care of at school. That should date me pretty well. On 5/11/10 3:04 PM, Mo McRoberts wrote: It got out of hand because the classic C language #include, according to my reading of the replies, apparently does not work in the Apple compile system. Or maybe it does. I looked at the referenced manual pages and still could not find anything to meet the original call. If, on the other hand, you are building software specific to Mac OS X, then the extensions come into play. When the include path has been exhausted, GCC and clang will search the framework path for matches for a given header in the form #include<FrameworkName/header.h>, exactly as described quite clearly in earlier messages in this thread. In searching the framework path, FrameworkName/header.h is expanded to /path/to/Framework.framework/Headers/header.h. So, SystemConfiguration/SystemConfiguration.h does not exist in any of the include paths, it must therefore be in one of the framework paths — in this case, it expands to /System/Library/Frameworks/SystemConfiguration.framework/Headers/SystemConfiguration.h, relative to the SDK root if one is specified… again, precisely as outlined earlier in this thread, and as described by the Apple documents. While it’s certainly a little different to what you might expect if you’re new at Mac OS X, it’s not especially complic ated, is clearly explained in the docs, and isn’t a million miles away from GCC automatically prepending $exec_prefix/lib/gcc-lib/$target/$gcc_version/include to the include path. Or for GCC to have an __extension__() attribute. Or for GCC to have an #include_next preprocessor directive. Or other compilers to have #pragma. If you’re delving into platform-specific stuff, RTFMing helps enormously. In this case, the issue was the inclusion of a user-space framework header in a kernel extension… when you’re dealing with kernel extensions, it’s *going* to be platform-specific stuff. [0] I don’t count myself amongst them, incidentally. This email sent to site_archiver(a)lists.apple.com

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