Cplex library gcc compilation link error - c

gcc -I/opt/cplex-studio-125/cplex/include -lcplex -L/opt/cplex-studio-125/cplex/lib/x86-64_sles10_4.1/static_pic mipex1.c
I'm trying to compile an example from cplex. -I option is fine. The -L option seems to be corrupt, since it can't find the function names.
Where is the error? In the specifiec link there is a libcplex.a.
/tmp/ccf5sKky.o: In function `main':
mipex1.c:(.text+0x9f): undefined reference to `CPXopenCPLEX'
mipex1.c:(.text+0xee): undefined reference to `CPXgeterrorstring'
mipex1.c:(.text+0x125): undefined reference to `CPXsetintparam'
mipex1.c:(.text+0x222): undefined reference to `CPXcreateprob'
mipex1.c:(.text+0x2e1): undefined reference to `CPXcopylp'
mipex1.c:(.text+0x334): undefined reference to `CPXcopyctype'
mipex1.c:(.text+0x380): undefined reference to `CPXmipopt'
mipex1.c:(.text+0x3cc): undefined reference to `CPXgetstat'
mipex1.c:(.text+0x403): undefined reference to `CPXgetobjval'
mipex1.c:(.text+0x474): undefined reference to `CPXgetnumrows'
mipex1.c:(.text+0x490): undefined reference to `CPXgetnumcols'
mipex1.c:(.text+0x4be): undefined reference to `CPXgetx'
mipex1.c:(.text+0x51c): undefined reference to `CPXgetslack'
mipex1.c:(.text+0x5f9): undefined reference to `CPXwriteprob'
mipex1.c:(.text+0x64d): undefined reference to `CPXfreeprob'
mipex1.c:(.text+0x697): undefined reference to `CPXcloseCPLEX'
mipex1.c:(.text+0x6e3): undefined reference to `CPXgeterrorstring'
collect2: error: ld returned 1 exit status

The order of appearance of the library matters. Change your compilation statement to
gcc -I/opt/cplex-studio-125/cplex/include mipex1.c L/opt/cplex-studio-125/cplex/lib/x86-64_sles10_4.1/static_pic -lcplex
(Generic version)
gcc -I/<path> -L<path> <source.c> -l<lib>
to put the library after the source file, so that, linker will search the library for the function called from the source file.

Related

Trying to generate assembly code from C

I have created an assembly code from a C project, but when i run it I get this compilation error:
Compilation Error
/usr/bin/x86_64-linux-gnu-ld: warning: cannot find entry symbol _start;
defaulting to 00000000004000b0
/tmp/tmpM7HOI5/squares.o: In function `main':
main.c:(.text+0x2e): undefined reference to `malloc'
main.c:(.text+0x43): undefined reference to `perror'
main.c:(.text+0x4d): undefined reference to `exit'
main.c:(.text+0x54): undefined reference to `stdin'
main.c:(.text+0x68): undefined reference to `fgets'
main.c:(.text+0xb5): undefined reference to `atoi'
main.c:(.text+0x12d): undefined reference to `free'
main.c:(.text+0x14d): undefined reference to `malloc'
main.c:(.text+0x158): undefined reference to `stdin'
main.c:(.text+0x16c): undefined reference to `fgets'
main.c:(.text+0x17f): undefined reference to `strtok'
main.c:(.text+0x18f): undefined reference to `atoi'
main.c:(.text+0x1b5): undefined reference to `strtok'
main.c:(.text+0x1c5): undefined reference to `atoi'
main.c:(.text+0x1ef): undefined reference to `strtok'
main.c:(.text+0x1ff): undefined reference to `atoi'
main.c:(.text+0x229): undefined reference to `strtok'
main.c:(.text+0x239): undefined reference to `atoi'
main.c:(.text+0x25e): undefined reference to `free'
main.c:(.text+0x2f6): undefined reference to `printf'
It seems that all library calls become undefined.
To compile I used:
gcc -std=c99 -Wall -O2 -lm -S main.c
Your GCC command only generates assembly code, but your error list is for a linker invocation.
I suspect the -lm option is causing the compiler driver to invoke the linker - it is not necessary to specify a library if you are generating only assembly for a single translation unit.
The linker is complaining about the lack of the C standard library and crt0.0 C runtime-start-up.
Remove the unnecessary -lm option - you are not intending to link, so teh library is irrelevant.
Your -lm links to the math library. Similarly, you need -lc to link to the C library.

hiredis "undefined reference to" compiler error

I want to compile the client for redis in C. I've downloaded and installed the libevent library and the hiredis files. I've used this command:
gcc -I/home/tasos/Dropbox/lists/hiredis example-libevent.c -levent
but I get these errors:
/tmp/ccxoerYJ.o: In function `redisLibeventReadEvent':
example-libevent.c:(.text+0x28): undefined reference to `redisAsyncHandleRead'
/tmp/ccxoerYJ.o: In function `redisLibeventWriteEvent':
example-libevent.c:(.text+0x56): undefined reference to `redisAsyncHandleWrite'
/tmp/ccxoerYJ.o: In function `getCallback':
example-libevent.c:(.text+0x2d2): undefined reference to `redisAsyncDisconnect'
/tmp/ccxoerYJ.o: In function `main':
example-libevent.c:(.text+0x393): undefined reference to `redisAsyncConnect'
example-libevent.c:(.text+0x3f3): undefined reference to `redisAsyncSetConnectCallback'
example-libevent.c:(.text+0x404): undefined reference to `redisAsyncSetDisconnectCallback'
example-libevent.c:(.text+0x45d): undefined reference to `redisAsyncCommand'
example-libevent.c:(.text+0x47d): undefined reference to `redisAsyncCommand'
collect2: ld returned 1 exit status
why isn't this working?
Use -levent and -lhiredis compile option in command.

"undefined reference" when trying to use lp_solve in C/C++ on Linux

I'm new to linear programming and C. I am trying to use the lp_solve library to solve a linear equation. The problem is I can't get the demo code to work.
As described in the documentation, I downloaded lp_solve_5.5_dev.gz to my Linux machine. I extracted the files into the same folder as my code and tried to compile:
~/Desktop/Code/CA$ cc -o demo demo.c
/tmp/ccpeN8ZV.o: In function `demo':
demo.c:(.text+0x31): undefined reference to `make_lp'
demo.c:(.text+0x62): undefined reference to `set_col_name'
demo.c:(.text+0x7d): undefined reference to `set_col_name'
demo.c:(.text+0xcf): undefined reference to `set_add_rowmode'
demo.c:(.text+0x150): undefined reference to `add_constraintex'
demo.c:(.text+0x1e6): undefined reference to `add_constraintex'
demo.c:(.text+0x274): undefined reference to `add_constraintex'
demo.c:(.text+0x29c): undefined reference to `set_add_rowmode'
demo.c:(.text+0x30b): undefined reference to `set_obj_fnex'
demo.c:(.text+0x327): undefined reference to `set_maxim'
demo.c:(.text+0x33b): undefined reference to `write_LP'
demo.c:(.text+0x34e): undefined reference to `set_verbose'
demo.c:(.text+0x359): undefined reference to `solve'
demo.c:(.text+0x383): undefined reference to `get_objective'
demo.c:(.text+0x3a6): undefined reference to `get_variables'
demo.c:(.text+0x3d2): undefined reference to `get_col_name'
demo.c:(.text+0x429): undefined reference to `delete_lp'
collect2: ld returned 1 exit status
When I add liblpsolve55.a to the command I get the following errors:
~/Desktop/Code/CA$ cc -o demo demo.c liblpsolve55.a
liblpsolve55.a(lp_lib.o): In function `scaled_floor':
lp_lib.c:(.text+0x6923): undefined reference to `floor'
liblpsolve55.a(lp_lib.o): In function `scaled_ceil':
lp_lib.c:(.text+0x6f03): undefined reference to `ceil'
liblpsolve55.a(lp_lib.o): In function `set_XLI':
lp_lib.c:(.text+0x7aa2): undefined reference to `dlclose'
lp_lib.c:(.text+0x7bb3): undefined reference to `dlopen'
lp_lib.c:(.text+0x7bd1): undefined reference to `dlsym'
lp_lib.c:(.text+0x7d8a): undefined reference to `dlsym'
lp_lib.c:(.text+0x7da6): undefined reference to `dlsym'
lp_lib.c:(.text+0x7dc2): undefined reference to `dlsym'
liblpsolve55.a(lp_lib.o): In function `set_BFP':
lp_lib.c:(.text+0x7eb4): undefined reference to `dlclose'
lp_lib.c:(.text+0x7fc3): undefined reference to `dlopen'
lp_lib.c:(.text+0x7fe1): undefined reference to `dlsym'
lp_lib.c:(.text+0x831a): undefined reference to `dlsym'
lp_lib.c:(.text+0x8336): undefined reference to `dlsym'
lp_lib.c:(.text+0x8352): undefined reference to `dlsym'
lp_lib.c:(.text+0x836e): undefined reference to `dlsym'
liblpsolve55.a(lp_lib.o):lp_lib.c:(.text+0x838a): more undefined references to `dlsym' follow
................
I understand that the lp_solve libraries are not loaded in my code. Can you please tell me how I can properly link the lp_solve libraries?
You're just missing some compiler flags to include the proper libraries. As danielko said, a quick google search on the missing libraries brings up some suggestions. E.g.
Linux c++ error: undefined reference to 'dlopen'
http://sourceforge.net/p/dev-cpp/discussion/48211/thread/3bd8b8a1
These suggest your compilation should be something more like:
cc -o demo demo.c -ldl -llpsolve55
and the lpsolve documentation suggests a command that includes the project directory such as:
cc -I/lp_solve_5.5 -I/lp_solve_5.5/bfp -I/lp_solve_5.5/bfp/bfp_etaPFI -I/lp_solve_5.5/colamd $src -o MyExe.exe -lm -ldl

Compiling libjpeg on Windows using cygwin?

Which is the best way to compile libjpeg on a Windows machine? Should I use Microsoft Visual Studio or can I use something else like Cygwin?
Note: when I use Cygwin and copy makefile.vc to Makefile, jconfig.vc to jconfig.h and run this sample code: http://www.cim.mcgill.ca/~junaed/code/libjpeg_sample.tar.gz
then the compiler produces the following errors:
$ gcc main.c
C:\cygwin\tmp\ccwChyeY.o:main.c:(.text+0x5a): undefined reference to `jpeg_std_error'
C:\cygwin\tmp\ccwChyeY.o:main.c:(.text+0x7e): undefined reference to `jpeg_CreateDecompress'
C:\cygwin\tmp\ccwChyeY.o:main.c:(.text+0x93): undefined reference to `jpeg_stdio_src'
C:\cygwin\tmp\ccwChyeY.o:main.c:(.text+0xa9): undefined reference to `jpeg_read_header'
C:\cygwin\tmp\ccwChyeY.o:main.c:(.text+0xb7): undefined reference to `jpeg_start_decompress'
C:\cygwin\tmp\ccwChyeY.o:main.c:(.text+0x11b): undefined reference to `jpeg_read_scanlines'
C:\cygwin\tmp\ccwChyeY.o:main.c:(.text+0x178): undefined reference to `jpeg_finish_decompress'
C:\cygwin\tmp\ccwChyeY.o:main.c:(.text+0x186): undefined reference to `jpeg_destroy_decompress'
C:\cygwin\tmp\ccwChyeY.o:main.c:(.text+0x1f6): undefined reference to `jpeg_std_error'
C:\cygwin\tmp\ccwChyeY.o:main.c:(.text+0x21a): undefined reference to `jpeg_CreateCompress'
C:\cygwin\tmp\ccwChyeY.o:main.c:(.text+0x22f): undefined reference to `jpeg_stdio_dest'
C:\cygwin\tmp\ccwChyeY.o:main.c:(.text+0x269): undefined reference to `jpeg_set_defaults'
C:\cygwin\tmp\ccwChyeY.o:main.c:(.text+0x27f): undefined reference to `jpeg_start_compress'
C:\cygwin\tmp\ccwChyeY.o:main.c:(.text+0x2c7): undefined reference to `jpeg_write_scanlines'
C:\cygwin\tmp\ccwChyeY.o:main.c:(.text+0x2e5): undefined reference to `jpeg_finish_compress'
C:\cygwin\tmp\ccwChyeY.o:main.c:(.text+0x2f3): undefined reference to `jpeg_destroy_compress'
collect2.exe: error: ld returned 1 exit status
Well, if you just want the .dll it is already compiled.
https://cygwin.com/cgi-bin2/package-grep.cgi?grep=libjpeg&arch=x86_64

Compilation error in GCC on Linux

I am trying to compile my code for GnuTLS, but on compiling it gives the following errors.
I have checked gnutls.h is present on my system in /usr/include/gnutls/.
What else can be the cause?
gcc -o tls.o tls.c
/tmp/ccfyZ1Bd.o: In function `main':
tls.c:(.text+0x1c): undefined reference to `gnutls_global_init'
tls.c:(.text+0x28): undefined reference to `gnutls_anon_allocate_client_credentials'
tls.c:(.text+0x3c): undefined reference to `gnutls_init'
tls.c:(.text+0x58): undefined reference to `gnutls_priority_set_direct'
tls.c:(.text+0x74): undefined reference to `gnutls_credentials_set'
tls.c:(.text+0x79): undefined reference to `tcp_connect'
tls.c:(.text+0x91): undefined reference to `gnutls_transport_set_ptr'
tls.c:(.text+0x9d): undefined reference to `gnutls_handshake'
tls.c:(.text+0xdc): undefined reference to `gnutls_perror'
tls.c:(.text+0x109): undefined reference to `gnutls_record_send'
tls.c:(.text+0x125): undefined reference to `gnutls_record_recv'
tls.c:(.text+0x154): undefined reference to `gnutls_strerror'
tls.c:(.text+0x1e6): undefined reference to `gnutls_bye'
tls.c:(.text+0x1f2): undefined reference to `tcp_close'
tls.c:(.text+0x1fe): undefined reference to `gnutls_deinit'
tls.c:(.text+0x20a): undefined reference to `gnutls_anon_free_client_credentials'
tls.c:(.text+0x20f): undefined reference to `gnutls_global_deinit'
collect2: ld returned 1 exit status
This is a linking error. You need to include some library with the -l flag. Taking a wild guess without knowing your setup, I would try -lgnutls

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