Library linking problem

[Eric Norum]

Etienne Fortin wrote:
> I made a library and am trying to link it with my RTEMS application.
> Strangely enough, GCC is not able to find the symbol he's looking for.
> Here's the process:
> 
> 
> Command line:
> 
> m68k-rtems-gcc --pipe -B/usr/rtems/install/m68k-rtems/m5282lite/lib/
> -specs bsp_specs -qrt
> ems   -g -Wall  -O4 -fomit-frame-pointer -g      -m5200 -Werror
> -L/usr/rtems/c3d-1.0
> /ulib/build/install/m68k/lib    -o o-optimize/c3dproto.exe
> o-optimize/wrapup.o    -lulib
>  ../entry/o-optimize/*.o  ../init/o-optimize/*.o
> ../menus/o-optimize/*.o  ../peripherals/
> o-optimize/*.o
> 
> 
> Errors:
> ../entry/o-optimize/main.o: In function `main':
> ../entry/o-optimize/main.o(.text+0x10): undefined reference to
> `UcfgInitialize'
> ../peripherals/o-optimize/AD9888.o: In function
> `AD9888_InitializeTarget':
> ../peripherals/o-optimize/AD9888.o(.text+0x30): undefined reference to
> `UcfgAddTarget'
> ../peripherals/o-optimize/ICS1523.o: In function
> `ICS1523_InitializeTarget':
> ../peripherals/o-optimize/ICS1523.o(.text+0x30): undefined reference to
> `UcfgAddTarget'
> ../peripherals/o-optimize/ICS307.o: In function
> `ICS307_InitializeTarget':
> ../peripherals/o-optimize/ICS307.o(.text+0x4a): undefined reference to
> `UcfgAddTarget'
> ../peripherals/o-optimize/TFP410.o: In function
> `TFP410_InitializeTarget':
> ../peripherals/o-optimize/TFP410.o(.text+0x40): undefined reference to
> `UcfgAddTarget'
> ../peripherals/o-optimize/THS8200.o: In function
> `THS8200_InitializeTarget':
> ../peripherals/o-optimize/THS8200.o(.text+0x40): undefined reference to
> `UcfgAddTarget'
> 
> 
> Content of libulib.a in /usr/rtems/c3d-1.0/ulib/build/install/m68k/lib:
> ucfg.o:     file format elf32-m68k
> 
> SYMBOL TABLE:
> 00000000 l    df *ABS*  00000000 ucfg.c
> 00000000 l    d  .text  00000000
> 00000000 l    d  .data  00000000
> 00000000 l    d  .bss   00000000
> 00000000 l    d  .debug_abbrev  00000000
> 00000000 l    d  .debug_info    00000000
> 00000000 l    d  .debug_line    00000000
> 00000000 l    d  .debug_frame   00000000
> 00000000 l    d  .debug_pubnames        0000000
> 00000000 l    d  .debug_aranges 00000000
> 00000000 l    d  .debug_str     00000000
> 00000000 l    d  .comment       00000000
> 00000000 g     F .text  0000006e UcfgInitialize
> 00000000         *UND*  00000000 malloc
> 0000006e g     F .text  000000da UcfgAddTarget
> 00000148 g     F .text  0000005a UcfgCheckTarge
> 00000000         *UND*  00000000 strlen
> 00000000         *UND*  00000000 strcpy
> 00000000         *UND*  00000000 strcmp
> 000001a2 g     F .text  00000054 UcfgConfigure
> 00000000         *UND*  00000000 ucfgin
> 00000000         *UND*  00000000 ucfgout
> 00000000         *UND*  00000000 ucfgparse
> 00000000         *UND*  00000000 free
> 000001f6 g     F .text  0000004e UcfgDestroy
> 
> 
> 
> Keep in mind that GCC doesn't complains that ulib doesn't exist. So, it
> DOES find it. So how comes it can't link with the UcfgAddTarget
> symbol???
> 
> 
> Etienne Fortin
> Sensio
> 
> 
> 
> 

Because libraries are searched exactly once at the point the appear on the 
command line.  You need to put your library *after* the object files which 
need it.

-- 
Eric Norum                                 norume at aps.anl.gov
Advanced Photon Source                     Phone: (630) 252-4793
Argonne National Laboratory