New package linking fails

[Martin Küttler]

On 09/01/2014 04:28 PM, Masti Ramya Jayaram wrote:
> Dear all,
>
> I am trying to create a new package under l4/pkg. The linking of the package fails and it has to do with the linker path but I am not sure how to fix it. Here are the details.
>
> Package structure: (relevant parts)
>
> l4/pkg/test/server/src/main.cc
> l4/pkg/test/server/src/folder1/test1.c
> l4/pkg/test/include/test1.h
>
> l4/pkg/test/server/src/Makefile
>
> PKGDIR          ?= ../..
> L4DIR           ?= $(PKGDIR)/../..
>
> TARGET          = $(PKGNAME)
>
> # list requirements of your program here
> REQUIRES_LIBS   = libsigma0 libirq l4util l4re_c-util
>
> # list your .c or .cc files here
> SRC_C           = folder1/test1.c
> SRC_CC          = main.cc
>
> include $(L4DIR)/mk/prog.mk
>
> The compilation of the package fails with an undefined reference in main.cc to a function in test1.c (defined through test1.h). All the object files are generated and I checked under build. What do you think is the issue?

Did you declare the function with extern "C" linkage in main.cc? Without 
that the linker won't find C-functions called from C++-files.


Martin