'undefined reference' error in gcce build

I am building by application for device using abld gcce build urel . But I am getting some errors. My application has some
userdefined Static libraries and a exe which links to these libraries. The main file(app.exe) uses some macros like APP_RAND
whose declaration is in one of the lib files. While building it is showing the following error..

..\Symbian\9.2\S60_3rd_FP1\EPOC32\RELEASE\ARMV5\UREL\EEXE.LIB \
-o "..\Symbian\9.2\S60_3rd_FP1\EPOC32\BUILD\folder\app\GCCE\UREL\app.exe" \
-Map "..\Symbian\9.2\S60_3rd_FP1\EPOC32\RELEASE\GCCE\UREL\app.exe.map" \
..\Symbian\9.2\S60_3rd_FP1\EPOC32\BUILD\folder\app\GCCE\UREL\accl.o: In function `a_px_msg':
Sipaccl.c:(.text+0x60c0): undefined reference to `rand_r'

Why is it showing this??