Hello Rob, I follow-up Daniel's RB series from Jonathan Corbet's summarry on LWN http://lwn.net/Articles/500355/ . I have attempted ourself to solve implementation of type safe tree containers for C more than 10 years ago (GAVL) and it is used in many of my own and our university projects and even in (at least three) companies for proprietary projects. I have done multiple reviews of the Daniel's RB series and I am confident that his approach is more clean and generic than mine. I would be happy if it can get into Linux kernel, because it makes use of RB trees much simpler (user does not need to care about details) and with much better potential to catch user errors. According to my review, there is only one possibly problematic preprocessor construct. The Linux kernel is already dependent on this CPP behavior (IS_ENABLED macro) anyway. If you are fan of other compilers, please, provide constructive help and debate there and test attached C code on compilers which you use and consider them as candidates to compile linux kernel. According to my test, there is problem with MSVC (free WDF version run under WINE to deliver our company open-source projects to unfortunate users using Windows). Version Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 15.00.30729.207 for 80x86 Copyright (C) Microsoft Corporation. All rights reserved. But that is compiler which breaks many standards and if GCC is not enough open to you then I expect that you do not mind if Linux kernel cannot be compiled by MSVC. So I do not see that as a problem. So again, please, test LLVM or other your beloved compilers and report if there is a problem. It would worth to have even user space version of the kernel RB tree code with Dainie's interface to run feasibility and performance tests in more environments quickly (as Daniel mentioned already). But it is not necessary for me to be convinced that provided changes should go into kernel because I am convinced already and offer my "Reviewed-by" confirmation. It would even worth to have this code available for user space projects and libraries use. But there is a problem that core part of the Linux RB code is GPL licensed and for library use LGPL, MPL or GPL with linking exception is usually required. Best wishes, Pavel Pisa e-mail: pisa@xxxxxxxxxxxxxxxx www: http://cmp.felk.cvut.cz/~pisa university: http://dce.fel.cvut.cz/ company: http://www.pikron.com/ #include <stdio.h> #define IFF_EMPTY(test, t, f) _iff_empty(__JUNK##test, t, f) #define __JUNK junk , #define _iff_empty(test_or_junk, t, f) __iff_empty(test_or_junk, t, f) #define __iff_empty(__ignored1, __ignored2, result, ...) result #define IS_EMPTY(arg) IFF_EMPTY(arg, 1, 0) #define TESTER_empty #define TESTER_filled filled int main(int argc, char *argv[]) { printf("IS_EMPTY for empty %d (should be 1)\n", IS_EMPTY(TESTER_empty)); printf("IS_EMPTY for filled %d (should be 0)\n", IS_EMPTY(TESTER_filled)); printf("IS_EMPTY for unknown %d (should be 0)\n", IS_EMPTY(TESTER_unknown)); printf("IS_EMPTY for nil %d (should be 1)\n", IS_EMPTY()); printf("IS_EMPTY for space %d (should be 1)\n", IS_EMPTY( )); printf("IS_EMPTY for comment %d (should be 1)\n", IS_EMPTY(/*test*/)); } -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
