Static Library Linking Problem using Autotool

[Wy kevinthesun]

Hi,

I am using GNU Autotool toolchain to work in Eclipse. I have some problems
with linking to static library.

First, I create a static library project "GPIOPin" and successfully
compiling it with following Makefile.am:

noinst_LIBRARIES = libGPIOPin.a
libGPIOPin_a_SOURCES = GPIOPin.cpp GPIOPin.h


AM_CXXFLAGS = @GPIOPin_CFLAGS@
AM_LDFLAGS = @GPIOPin_LIBS@

CLEANFILES = *~


Then I created a test project "Test3" which included "GPIOPin.h". I wrote
the following Makefile.am for Test3:

bin_PROGRAMS = Test3
Test3_SOURCES = Test3.cpp

Test3_LDFLAGS = -L/home/kevinthefire/workspace/GPIOPin/src
Test3_LDADD =  /home/kevinthefire/workspace/GPIOPin/src/libGPIOPin.a

AM_CXXFLAGS = -I/home/kevinthefire/workspace/GPIOPin/src
AM_LDFLAGS = @Test3_LIBS@ @Test3_LDFLAGS@
AM_LDADD = @Test3_LDADD@
CLEANFILES = *~

It was compiled and running well.

Then I tried to create another static library "Encoder" which needed to
include GPIOPin library. I wrote the following Makefile.am:

noinst_LIBRARIES = libEncoder.a
libEncoder_a_SOURCES = Encoder.cpp Encoder.h

Encoder_LDFLAGS = -L/home/kevinthefire/workspace/GPIOPin/src
Encoder_LDADD =  /home/kevinthefire/workspace/GPIOPin/src/libGPIOPin.a

AM_CXXFLAGS = -I/home/kevinthefire/workspace/GPIOPin/src
AM_LDFLAGS = @Encoder_LIBS@ @Encoder_LDFLAGS@
AM_LDADD = @Encoder_LDADD@
CLEANFILES = *~

It could be compiled well.

Finally I tried to test Encoder library as before. I create "Test6" Project
which only included "Encoder.h" and wrote Makefile.am similarly as Test3:

bin_PROGRAMS = Test6
Test6_SOURCES = Test6.cpp

Test6_LDFLAGS = -L/home/kevinthefire/workspace/Encoder/src
Test6_LDADD =  /home/kevinthefire/workspace/Encoder/src/libEncoder.a

AM_CXXFLAGS = -I/home/kevinthefire/workspace/Encoder/src
AM_LDFLAGS = @Test6_LIBS@ @Test6_LDFLAGS@
AM_LDADD = @Test6_LDADD@
CLEANFILES = *~

It gave errors:
Description    Resource    Path    Location    Type
make[1]: *** [all-recursive] Error 1    Test6             C/C++ Problem
make[2]: *** [Test6] Error 1    Test6             C/C++ Problem
undefined reference to `GpIoPin::setEdge(char*)'    Encoder.cpp
/Encoder/src    line 87    C/C++ Problem
undefined reference to `GpIoPin::setEdge(char*)'    Encoder.cpp
/Encoder/src    line 88    C/C++ Problem
make: *** [all] Error 2    Test6             C/C++ Problem
more undefined references to `GpIoPin::~GpIoPin()' follow    Test6
line 25    C/C++ Problem
undefined reference to `GpIoPin::~GpIoPin()'    Encoder.h
/Encoder/src    line 25    C/C++ Problem
undefined reference to `GpIoPin::~GpIoPin()'    Encoder.h
/Encoder/src    line 26    C/C++ Problem
undefined reference to `GpIoPin::GpIoPin(unsigned int, bool)'
Encoder.h    /Encoder/src    line 25    C/C++ Problem

It seems that the compiler couldn't link to GPIOPIn library through Encoder
library? So I modified Makefile.am of Test6 as:

bin_PROGRAMS = Test6
Test6_SOURCES = Test6.cpp

Test6_LDFLAGS = -L/home/kevinthefire/workspace/Encoder/src
-L/home/kevinthefire/workspace/GPIOPin/src
Test6_LDADD =  /home/kevinthefire/workspace/Encoder/src/libEncoder.a
/home/kevinthefire/workspace/GPIOPin/src/libGPIOPin.a

AM_CXXFLAGS = -I/home/kevinthefire/workspace/Encoder/src
-I/home/kevinthefire/workspace/GPIOPin/src
AM_LDFLAGS = @Test6_LIBS@ @Test6_LDFLAGS@
AM_LDADD = @Test6_LDADD@
CLEANFILES = *~

I just added information of GPIOPin library and it compiled well!

Now I am wondering why I can't write Makefile.am of Test6 as simple as
Test3, but have to list all the library information(GPIOPin and Encoder).
If my Encoder library includes several libraries I created, writing
Makefile.am would be trouble.

Thank you for any help!

Kevin