I have a couple of libraries that are created using avr-ar. Each contains a few objects.
The objects in library1 need symbols from objects in library2. The problem is that when I try to compile the whole thing I get undefined reference issues.
This is where it's failing, there's nothing fancy going on in $(INCLUDE) $(CFLAGS) $(LIBS)
CFLAGS=-mmcu=atmega328p -DF_CPU=16000000UL -Os -w -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums
LIBS=library1.a library2.a
$(CXX) $(INCLUDE) $^ $(CFLAGS) -o $@ $(LIBS)
I'm running Ubuntu 12.04 and
Using built-in specs.
COLLECT_GCC=avr-g++
COLLECT_LTO_WRAPPER=/usr/lib/gcc/avr/4.5.3/lto-wrapper
Target: avr
Configured with: ../src/configure -v --enable-languages=c,c++ --prefix=/usr/lib --infodir=/usr/share/info --mandir=/usr/share/man --bindir=/usr/bin --libexecdir=/usr/lib --libdir=/usr/lib --enable-shared --with-system-zlib --enable-long-long --enable-nls --without-included-gettext --disable-libssp --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=avr
Thread model: single
gcc version 4.5.3 (GCC)
If I extract the objects from the libraries and put the all in a library, everything goes well.
I would like to keep them separate, is there a way to achieve this?
you could try making the linker do a recursive link by grouping the libraries. I havn't checked the following but maybe change:
LIBS=library1.a library2.a
To
LIBS=-Wl,--start-group library1.a library2.a -Wl,--end-group
This will cause the linker to go back and forth until all symbols are defined, at a linker performance cost. This is useful when two libraries depend on each other because the linker usually only passes each file once.
Hope this helps