RT-Thread/rt-thread — pull request #159 by grissiom (2013-09-23 03:33:33+00:00)
Title: kservice: export vsnprintf as rt_vsnprintf

vsnprintf is a common string function that could be used in many places.
Using both vsnprintf in libc and vsnprintf in the RTT could make a
bigger image. Moreover, if newlib is enabled when compiling with GCC,
referencing vsnprintf will lead to link error:

.../arm-none-eabi/lib/armv7-ar/thumb/softfp/libc.a(lib_a-sbrkr.o):
In function `_sbrk_r':
sbrkr.c:(.text._sbrk_r+0xc): undefined reference to `_sbrk'
collect2: error: ld returned 1 exit status

Using rt_vsnprintf could avoid such problem.