[Wireshark-dev] Difference between Autofoo and CMake build ?
(For Jörg Mayer) While reviewing the new ceph dissector [1], two issues cropped up where my build on Linux (using Autofoo) apparently gave different results then a build by Kevin Cox (the submitter of the new dissector) using CMake on Linux. He used GCC 4.9.1 and CMake while I used GCC 4.9.0 and Autofoo. 1. The Autofoo compile indicated an unused but set variable The CMake apparently did not. Different CFlags ? 2. The ceph dissector had several value_string_ext structs defined as 'static const ...'. The Wireshark built with CMake worked AOK when the ceph dissector used the extended value strings for the first time (i.e., no exceptions). The Wireshark built with Autofoo trapped when the extended value string structs were used for the first time (when there was an attempt to write to the struct). IOW: In one case, the structs were apparently not in a r/o section while in the other they apparently were. I've no idea if this difference has anything to do with CMake vs Autofoo. Thoughts ? [1] https://code.wireshark.org/review/#/c/1889/ ___ Sent via:Wireshark-dev mailing list wireshark-dev@wireshark.org Archives:http://www.wireshark.org/lists/wireshark-dev Unsubscribe: https://wireshark.org/mailman/options/wireshark-dev mailto:wireshark-dev-requ...@wireshark.org?subject=unsubscribe
Re: [Wireshark-dev] Difference between Autofoo and CMake build ?
On Thu, Jul 24, 2014 at 11:58:51AM -0400, Bill Meier wrote: While reviewing the new ceph dissector [1], two issues cropped up where my build on Linux (using Autofoo) apparently gave different results then a build by Kevin Cox (the submitter of the new dissector) using CMake on Linux. He used GCC 4.9.1 and CMake while I used GCC 4.9.0 and Autofoo. 1. The Autofoo compile indicated an unused but set variable The CMake apparently did not. Should not be: I do (or at least did) get these messages regularly with CMake. Different CFlags ? As the order of flags in both files is rather random I did a bit of grepping, sorting and some manual editing. It looks like the flags should be the same. 2. The ceph dissector had several value_string_ext structs defined as 'static const ...'. The Wireshark built with CMake worked AOK when the ceph dissector used the extended value strings for the first time (i.e., no exceptions). The Wireshark built with Autofoo trapped when the extended value string structs were used for the first time (when there was an attempt to write to the struct). IOW: In one case, the structs were apparently not in a r/o section while in the other they apparently were. I've no idea if this difference has anything to do with CMake vs Autofoo. Thoughts ? Not on first sight. Maybe you can do a comparison on your system where all the other tools are identical? Ciao Jörg -- Joerg Mayer jma...@loplof.de We are stuck with technology when what we really want is just stuff that works. Some say that should read Microsoft instead of technology. ___ Sent via:Wireshark-dev mailing list wireshark-dev@wireshark.org Archives:http://www.wireshark.org/lists/wireshark-dev Unsubscribe: https://wireshark.org/mailman/options/wireshark-dev mailto:wireshark-dev-requ...@wireshark.org?subject=unsubscribe
Re: [Wireshark-dev] Difference between Autofoo and CMake build ?
On 24/07/14 12:36, Joerg Mayer wrote: On Thu, Jul 24, 2014 at 11:58:51AM -0400, Bill Meier wrote: While reviewing the new ceph dissector [1], two issues cropped up where my build on Linux (using Autofoo) apparently gave different results then a build by Kevin Cox (the submitter of the new dissector) using CMake on Linux. He used GCC 4.9.1 and CMake while I used GCC 4.9.0 and Autofoo. 1. The Autofoo compile indicated an unused but set variable The CMake apparently did not. Should not be: I do (or at least did) get these messages regularly with CMake. I usually get these too. Maybe it was a compiler bug or something. I will try checking out the old version and doing a clean build to see if the warning/error shows up now. 2. The ceph dissector had several value_string_ext structs defined as 'static const ...'. The Wireshark built with CMake worked AOK when the ceph dissector used the extended value strings for the first time (i.e., no exceptions). The Wireshark built with Autofoo trapped when the extended value string structs were used for the first time (when there was an attempt to write to the struct). IOW: In one case, the structs were apparently not in a r/o section while in the other they apparently were. I've no idea if this difference has anything to do with CMake vs Autofoo. Thoughts ? Not on first sight. Maybe you can do a comparison on your system where all the other tools are identical? I just ran a test build and ./autogen ./configure make performed the same way. It seems that GCC 4.9.1 doesn't want to put those structures in .rodata on my system for whatever reason. Also of note, the header_field_info.strings member is defined as 'const void*' but when passed an extended value string it appears that the const is casted away. This should probably be changed in order to be type safe, as an error would have been raised if it was declared properly as 'void*'. Of course the downside to this is that regular value strings will not be allowed to be const, but that can be worked around by modifying the VALS() macro to cast away that const-ness as value_string's will always be treated const. Ideally there would be a more type safe way to do this. signature.asc Description: OpenPGP digital signature ___ Sent via:Wireshark-dev mailing list wireshark-dev@wireshark.org Archives:http://www.wireshark.org/lists/wireshark-dev Unsubscribe: https://wireshark.org/mailman/options/wireshark-dev mailto:wireshark-dev-requ...@wireshark.org?subject=unsubscribe
Re: [Wireshark-dev] Difference between Autofoo and CMake build ?
On 24/07/14 12:54, Kevin Cox wrote: On 24/07/14 12:36, Joerg Mayer wrote: On Thu, Jul 24, 2014 at 11:58:51AM -0400, Bill Meier wrote: While reviewing the new ceph dissector [1], two issues cropped up where my build on Linux (using Autofoo) apparently gave different results then a build by Kevin Cox (the submitter of the new dissector) using CMake on Linux. He used GCC 4.9.1 and CMake while I used GCC 4.9.0 and Autofoo. 1. The Autofoo compile indicated an unused but set variable The CMake apparently did not. Should not be: I do (or at least did) get these messages regularly with CMake. I usually get these too. Maybe it was a compiler bug or something. I will try checking out the old version and doing a clean build to see if the warning/error shows up now. I just did a complete rebuild and I am now getting this error under CMake as well. I must have messed up my CMake configure somehow. signature.asc Description: OpenPGP digital signature ___ Sent via:Wireshark-dev mailing list wireshark-dev@wireshark.org Archives:http://www.wireshark.org/lists/wireshark-dev Unsubscribe: https://wireshark.org/mailman/options/wireshark-dev mailto:wireshark-dev-requ...@wireshark.org?subject=unsubscribe
Re: [Wireshark-dev] Difference between Autofoo and CMake build ?
On 7/24/2014 2:09 PM, Kevin Cox wrote: I usually get these too. Maybe it was a compiler bug or something. I will try checking out the old version and doing a clean build to see if the warning/error shows up now. I just did a complete rebuild and I am now getting this error under CMake as well. I must have messed up my CMake configure somehow. Kevin: Ok; thanks for taking the time to do this. (I always like to follow thru on things to make sure there isn't some issue we need to address). Bill ___ Sent via:Wireshark-dev mailing list wireshark-dev@wireshark.org Archives:http://www.wireshark.org/lists/wireshark-dev Unsubscribe: https://wireshark.org/mailman/options/wireshark-dev mailto:wireshark-dev-requ...@wireshark.org?subject=unsubscribe
