I am compiling a USB device driver using GNU C in Eclipse under
Fedora 10.

This necessitates using #include "/usr/include/usb.h"

so that the usb.h declarations (types and functions) are visible to the compiler. This compiles!

Now the shared objects

/usr/lib/libusb-0.1.so.4.4.4 and /usr/lib/libusbpp-0.1.so.4.4.4 need to be added to the linker.

To do this I went to the

(1) eclipse project explorer and clicked on the the project-> properties
(2) C/C++ Build -> Settings
(3) Tool Settings -> GCC C Linker -> Share Library Settings

IN THE Share Library Setting (tab)

(4) I then checked the shared check box.
(5) Share Object Name: ==> I entered :

/usr/lib/libusb-0.1.so.4.4.4 /usr/lib/libusbpp-0.1.s0.4.4.4


(6) Import Library Name: ==> I entered:

(a)/usr/lib/libusb /usr/lib/libusbpp

NOTE: That this Import LIbrary Name was also left blank

IS THIS FIELD NECESSARY FOR A SHARE OBJECT ???

(7) DEF File Name: ==> I entered:

/usr/lib/libusb.def /usr/lib/libusbpp.def



NO MATTER WHAT IS ENTERED HERE


The linker error is generated from the last field generates the
following error:gcc:

gcc: /usr/lib/libusbpp.def: No such file or directory
gcc: /usr/lib/libusbpp.def: No such file or directory
gcc: /usr/lib/libusbpp.def: No such file or directory

THE QUESTIONS FOR THIS POSTING ARE:

1) What should the setting for the Import Library Name: for a
share object be ---LEFT BLANK?????

2) What should the DEF File Name: Setting be for a share object

3) What are the specifications for a .def file???

You usually should only need to add the external libs to the linker settings (i.e. in your case "usb" and "usbpp", the rest will be added automatically by Eclipse) and if your output file is a shared object just tick the "Shared" checkbox in the 'Shared Library Settings', which should be all you have to do here from my experience.

Furthermore, the name, type, extension and prefix you can also easily setup in the 'Build Artifact' options tab.

The program now links with only the Shared named objects defined as

/usr/lib/libusb-0.1.so.4.4.4
and

/usr/lib/libusbpp-0.1.so.4.4.4 !

The issue now these shared objects are causing a segmentation fault when initiating the
Debug. Please see below



5239-gdb-set confirm off
5239^done
(gdb)
5240-gdb-set width 0
5240^done
(gdb)
5241-gdb-set height 0
5241^done
(gdb)
5242-interpreter-exec console echo
5242^done
(gdb)
5243-gdb-show prompt
5243^done,value="(gdb) "
(gdb)
5244-gdb-set auto-solib-add on
5244^done
(gdb)
5245-gdb-set stop-on-solib-events 0
5245^done
(gdb)
5246-gdb-set stop-on-solib-events 1
5246^done
(gdb)
5247-gdb-show solib-search-path
5247^done,value=""
(gdb)
5248-gdb-set solib-search-path /usr/lib/libusb-0.1.so.4.4.4:/usr/lib/libusbpp-0.1.so.4.4.4
5248^done
(gdb)
5249
&"\n"
5249^done
(gdb)
5250-environment-cd /home/ddeeks/workspace/PocketPalNU
5250^done
(gdb)

5251-environment-directory /home/ddeeks/workspace/PocketPalNU /home/ddeeks/workspace/PocketPalNU/.settings /home/ddeeks/workspace/PocketPalNU/Debug /home/ddeeks/workspace/PocketPalNU/Release
5251^done,source-path="/home/ddeeks/workspace/PocketPalNU:/home/ddeeks/workspace/PocketPalNU/.settings:/home/ddeeks/workspace/PocketPalNU/Debug:/home/ddeeks/workspace/PocketPalNU/Release:$cdir:$cwd"
(gdb)
5252 info threads
&"info threads\n"
&"No registers.\n"
5252^error,msg="No registers."
(gdb)
5253-data-list-register-names
5253^done,register-names=["eax","ecx","edx","ebx","esp","ebp","esi","edi","eip","eflags","cs","ss","ds","es","fs","gs","st0"," st1","st2","st3","st4","st5","st6","st7","fctrl","fstat","ftag","fiseg","fioff","foseg","fooff","fop ","xmm0","xmm1","xmm2","xmm3","xmm4","xmm5","xmm6","xmm7","mxcsr","orig_eax","mm0","mm1","mm2","mm3" ,"mm4","mm5","mm6","mm7"]
(gdb)
5254-break-insert /home/ddeeks/workspace/PocketPalNU/test1.c:118
5254^done,bkpt={number="1",type="breakpoint",disp="keep",enabled="y",addr="0x00001015",func="main",f ile="../test1.c",fullname="/home/ddeeks/workspace/PocketPalNU/test1.c",line="118",times="0"}
(gdb)
5255-break-insert -t main
5255^done,bkpt={number="2",type="breakpoint",disp="del",enabled="y",addr="0x00001005",func="main",fi le="../test1.c",fullname="/home/ddeeks/workspace/PocketPalNU/test1.c",line="106",times="0"}
(gdb)
5256-exec-run
5256^running
(gdb)
5256*stopped,reason="signal-received",signal-name="SIGSEGV",signal-meaning="Segmentation fault",thread-id="0",frame={addr="0x00000001",func="??",args=[]}
(gdb)
5257 info proc
&"info proc\n"
~"process 23638\n"
~"cmdline = '/home/ddeeks/workspace/PocketPalNU/Debug/test1.out'\n"
~"cwd = '/home/ddeeks/workspace/PocketPalNU'\n"
~"exe = '/home/ddeeks/workspace/PocketPalNU/Debug/test1.out'\n"
5257^done
(gdb)
5258 info threads
&"info threads\n"
&"warning: Couldn't restore frame in current thread, at frame 0\n"
~"0x00000001 in ?? ()\n"
5258^done
(gdb)
5259-stack-info-depth
5259^done,depth="1"
(gdb)
5260-stack-list-frames 0 1
5260^done,stack=[frame={level="0",addr="0x00000001",func="??"}]
(gdb)
5261-data-list-changed-registers
5261^done,changed-registers=["0","1","2","3","4","5","6","7","8","9","10","11","12","13","14","15","16","17","18","19","20","21", "22","23","24","25","26","27","28","29","30","31","32","33","34","35","36","37","38","39","40"," 41"]
(gdb)
5262 info sharedlibrary
&"info sharedlibrary\n"
~"No shared libraries loaded at this time.\n"
5262^done
(gdb)
5263 info signal SIGSEGV
&"info signal SIGSEGV\n"
~"Signal Stop\tPrint\tPass to program\tDescription\n"
~"SIGSEGV Yes\tYes\tYes\t\tSegmentation fault\n"
5263^done
(gdb)








5264-data-disassemble -s 0x1 -e 0x65 -- 0
Cannot access memory at address 0x1
&"Cannot access memory at address 0x1\n"
5264^error,msg="Cannot access memory at address 0x1"
(gdb)
5265-stack-list-arguments 0 0 0
5265^done,stack-args=[frame={level="0",args=[]}]
(gdb)
5266-stack-list-locals 0
5266^done,locals=[]
(gdb)


DO I NEED TO EXPLICITLY LOAD THE SHARED LIBRARY OBJECTS???
and if so how???



Regards

Dan

If you have the shared objects in your linker settings and the project compiles fine, then all should be ok.

I can't decipher what gdb is outputting, but if you want to try to load the shared objects manually you can use 'dlopen', 'dlsym' et al (libdl needs to be linked here).

Thank you for your help