Re: Bullseye: Linker Can't Find libgps Library
On Mon, 13 Jul 2020 20:28:59 +0200 Sven Joachim wrote: > Not really, the reason is that in Bullseye gcc now passes the > --as-needed option to the linker to reduce unnecessary linking of > libraries (and dependencies in the Debian package system). Nice. Thanks for the clarification. -- Does anybody read signatures any more? https://charlescurley.com https://charlescurley.com/blog/
Re: Bullseye: Linker Can't Find libgps Library
On 2020-07-12 15:44 -0600, Charles Curley wrote: > On Sun, 12 Jul 2020 22:04:54 +0200 > Sven Joachim wrote: > >> I am rather surprised that it does, for I have learned that you always >> need to put libraries to link with at the end of the gcc commandline, >> i.e. >> >> gcc -Wall -ggdb -o gpsclient gpsclient.c -lm -lgps >> >> should work. > > Bingo. > > charles@white:~/versioned/gpsclient$ gcc -Wall -o gpsclient gpsclient.c -lm > -lgps > gpsclient.c:72:2: warning: #warning Setting up for API version 9.0 [-Wcpp] >72 | #warning Setting up for API version 9.0 > | ^~~ > charles@white:~/versioned/gpsclient$ > > Worked correctly. Thank you. Interesting. > > This is a change from Buster, gcc (Debian 9.3.0-14) 9.3.0 versus gcc > (Debian 8.3.0-6) 8.3.0. I conjecture the reason is so that gcc can > accommodate multiple source files on one line, each with their own > libraries. Something like: > > gcc -Wall -o snark foo.c -la -lb -lc bar.c -lb -lc -ld Not really, the reason is that in Bullseye gcc now passes the --as-needed option to the linker to reduce unnecessary linking of libraries (and dependencies in the Debian package system). According to the binutils documentation, , | '--as-needed' causes a DT_NEEDED tag to only be emitted for a library | that _at that point in the link_ satisfies a non-weak undefined symbol | reference from a regular object file or, if the library is not found in | the DT_NEEDED lists of other needed libraries, a non-weak undefined | symbol reference from another needed dynamic library. Object files or | libraries appearing on the command line _after_ the library in question | do not affect whether the library is seen as needed. ` HTH, Sven
Re: Bullseye: Linker Can't Find libgps Library
On Sun, 12 Jul 2020 22:04:54 +0200 Sven Joachim wrote: > I am rather surprised that it does, for I have learned that you always > need to put libraries to link with at the end of the gcc commandline, > i.e. > > gcc -Wall -ggdb -o gpsclient gpsclient.c -lm -lgps > > should work. Bingo. charles@white:~/versioned/gpsclient$ gcc -Wall -o gpsclient gpsclient.c -lm -lgps gpsclient.c:72:2: warning: #warning Setting up for API version 9.0 [-Wcpp] 72 | #warning Setting up for API version 9.0 | ^~~ charles@white:~/versioned/gpsclient$ Worked correctly. Thank you. Interesting. This is a change from Buster, gcc (Debian 9.3.0-14) 9.3.0 versus gcc (Debian 8.3.0-6) 8.3.0. I conjecture the reason is so that gcc can accommodate multiple source files on one line, each with their own libraries. Something like: gcc -Wall -o snark foo.c -la -lb -lc bar.c -lb -lc -ld -- Does anybody read signatures any more? https://charlescurley.com https://charlescurley.com/blog/
Re: Bullseye: Linker Can't Find libgps Library
On 2020-07-12 13:16 -0600, Charles Curley wrote: > I am trying to compile a gpsd client on a i686 bullseye machine. It > appears the compiler can find the include file for libgps, gps.h. > However, the linker cannot find the library. > > gcc -Wall -ggdb -lm -lgps -o gpsclient gpsclient.c > gpsclient.c:64:2: warning: #warning Setting up for API version 9.0 [-Wcpp] >64 | #warning Setting up for API version 9.0 > | ^~~ > /usr/bin/ld: /tmp/ccCsxl8F.o: in function `exitHandler': > /home/charles/versioned/gpsclient/gpsclient.c:130: undefined reference to > `gps_stream' > /usr/bin/ld: /home/charles/versioned/gpsclient/gpsclient.c:131: undefined > reference to `gps_close' > /usr/bin/ld: /tmp/ccCsxl8F.o: in function `showData': > /home/charles/versioned/gpsclient/gpsclient.c:229: undefined reference to > `timespec_to_iso8601' > /usr/bin/ld: /tmp/ccCsxl8F.o: in function `main': > /home/charles/versioned/gpsclient/gpsclient.c:474: undefined reference to > `gps_open' > /usr/bin/ld: /home/charles/versioned/gpsclient/gpsclient.c:477: undefined > reference to `gps_errstr' > /usr/bin/ld: /home/charles/versioned/gpsclient/gpsclient.c:503: undefined > reference to `gps_stream' > /usr/bin/ld: /home/charles/versioned/gpsclient/gpsclient.c:506: undefined > reference to `gps_waiting' > /usr/bin/ld: /home/charles/versioned/gpsclient/gpsclient.c:509: undefined > reference to `gps_read' > /usr/bin/ld: /home/charles/versioned/gpsclient/gpsclient.c:515: undefined > reference to `gps_stream' > collect2: error: ld returned 1 exit status > > Compilation exited abnormally with code 1 at Sun Jul 12 12:11:46 > > This compiles and runs on Buster on AMD64 architecture. I am rather surprised that it does, for I have learned that you always need to put libraries to link with at the end of the gcc commandline, i.e. gcc -Wall -ggdb -o gpsclient gpsclient.c -lm -lgps should work. Cheers, Sven
Bullseye: Linker Can't Find libgps Library
I am trying to compile a gpsd client on a i686 bullseye machine. It appears the compiler can find the include file for libgps, gps.h. However, the linker cannot find the library. gcc -Wall -ggdb -lm -lgps -o gpsclient gpsclient.c gpsclient.c:64:2: warning: #warning Setting up for API version 9.0 [-Wcpp] 64 | #warning Setting up for API version 9.0 | ^~~ /usr/bin/ld: /tmp/ccCsxl8F.o: in function `exitHandler': /home/charles/versioned/gpsclient/gpsclient.c:130: undefined reference to `gps_stream' /usr/bin/ld: /home/charles/versioned/gpsclient/gpsclient.c:131: undefined reference to `gps_close' /usr/bin/ld: /tmp/ccCsxl8F.o: in function `showData': /home/charles/versioned/gpsclient/gpsclient.c:229: undefined reference to `timespec_to_iso8601' /usr/bin/ld: /tmp/ccCsxl8F.o: in function `main': /home/charles/versioned/gpsclient/gpsclient.c:474: undefined reference to `gps_open' /usr/bin/ld: /home/charles/versioned/gpsclient/gpsclient.c:477: undefined reference to `gps_errstr' /usr/bin/ld: /home/charles/versioned/gpsclient/gpsclient.c:503: undefined reference to `gps_stream' /usr/bin/ld: /home/charles/versioned/gpsclient/gpsclient.c:506: undefined reference to `gps_waiting' /usr/bin/ld: /home/charles/versioned/gpsclient/gpsclient.c:509: undefined reference to `gps_read' /usr/bin/ld: /home/charles/versioned/gpsclient/gpsclient.c:515: undefined reference to `gps_stream' collect2: error: ld returned 1 exit status Compilation exited abnormally with code 1 at Sun Jul 12 12:11:46 This compiles and runs on Buster on AMD64 architecture. I have run ldconfig manually. root@white:/usr/lib/i386-linux-gnu# ldconfig -v | fgrep gps ldconfig: Can't stat /usr/local/lib/i386-linux-gnu: No such file or directory ldconfig: Can't stat /usr/local/lib/i686-linux-gnu: No such file or directory ldconfig: Can't stat /lib/i686-linux-gnu: No such file or directory ldconfig: Can't stat /usr/lib/i686-linux-gnu: No such file or directory ldconfig: Path `/lib/i386-linux-gnu' given more than once ldconfig: Path `/usr/lib/i386-linux-gnu' given more than once ldconfig: /lib/i386-linux-gnu/ld-2.30.so is the dynamic linker, ignoring libgps.so.26 -> libgps.so.26.0.0 root@white:/usr/lib/i386-linux-gnu# uname -a Linux white 5.7.0-1-686 #1 SMP Debian 5.7.6-1 (2020-06-24) i586 GNU/Linux root@white:/usr/lib/i386-linux-gnu# This also works on buster AMD64 when I have gpsd version 3.20.12 loaded from buster backports. This is the same version that is in bullseye. -- Does anybody read signatures any more? https://charlescurley.com https://charlescurley.com/blog/
