In my project, the modules are organized in sub-layers for convenience.
My project hierarchy hierarchy:
$ ls -R
.: configure.in Makefile.am Makefile.cvs src
./src: log Makefile.am main.cpp
./src/log: log.cpp Makefile.am
configure.in:
AC_INIT(configure.in)
AM_CONFIG_HEADER(config.h)
AM_INIT_AUTOMAKE(myapp, 0.1)
AC_LANG_CPLUSPLUS
AC_PROG_CXX
AM_PROG_LIBTOOL
AC_OUTPUT(Makefile src/Makefile src/log/Makefile)
Makefile.am:
AUTOMAKE_OPTIONS = foreign
SUBDIRS = src
Makefile.cvs:
default:
aclocal
libtoolize --force --copy
autoheader
automake --add-missing --copy
autoconf
Src / makefile.am
bin_PROGRAMS = myapp
myapp_SOURCES = main.cpp
SUBDIRS = log
myapp_LDADD = $(top_builddir)/src/log/liblog.la
CSI / Magazine / Makefile.am:
INCLUDES = $(all_includes)
METASOURCES = AUTO
noinst_LTLIBRARIES = liblog.la
liblog_la_SOURCES = log.cpp
src / main.cpp: contains int main(){}, src / log / log.cpp contains void f(){}.
The call makeproduces (edited for brevity):
libtool --mode=compile g++ -MT log.lo -MD -MP -MF .deps/log.Tpo -c -o log.lo log.cpp
libtool: compile: g++ -MT log.lo -MD -MP -MF .deps/log.Tpo -c log.cpp -fPIC -DPIC -o .libs/log.o
libtool: compile: g++ -MT log.lo -MD -MP -MF .deps/log.Tpo -c log.cpp -o log.o >/dev/null 2>&1
mv -f .deps/log.Tpo .deps/log.Plo
libtool --mode=link g++ -o liblog.la log.lo
libtool: link: ar cru .libs/liblog.a .libs/log.o
libtool: link: ranlib .libs/liblog.a
libtool: link: ( cd ".libs" && rm -f "liblog.la" && ln -s "../liblog.la" "liblog.la" )
g++ -MT main.o -MD -MP -MF .deps/main.Tpo -c -o main.o main.cpp
mv -f .deps/main.Tpo .deps/main.Po
libtool --mode=link g++ -o myapp main.o ../src/log/liblog.la
libtool: link: g++ -o myapp main.o ../src/log/.libs/liblog.a
The problem is in the first three lines: log.cpp compiled twice!
Question: why does it not just compile once - takes half the time?
note: I have no idea what I'm doing - autotools is black magic for me, but we have to use it in our place. I don’t understand the documents.
Iraimbilanja