c++ - Building static libraries on Mac using CMake and GCC?

Question

Greetings all,

I have a static library which I later link with my application. My development environment is CMake, GCC (Linux, Mac), MinGW (Windows).

I can compile the static library without any problem on Linux and Windows. (I can even build shared libraries in my application on Mac).

EDIT: I compiled the library as a SHARED library and it worked fine!!

I have configured CMakeFile as follows to build the static library:

add_library(centi STATIC ${base_srcs} ${crv_srcs} ${node_srcs} ${trnk_srcs} ${defl_srcs} ${infl_srcs} ${track_srcs} ${callback_srcs} ${extract_srcs})

During linking phase, it gives following errors and build the "libcenti.a" somehow.

Linking C static library
lib/libcenti.a /usr/bin/ranlib: file:
lib/libcenti.a(crv_in_rgn_to_bnry_img.c.o)
has no symbols /usr/bin/ranlib: file:
lib/libcenti.a(crv_initialize_by_circle.c.o)
has no symbols /usr/bin/ranlib: file:
lib/libcenti.a(crv_initialize_flgs.c.o)
has no symbols /usr/bin/ranlib: file:
lib/libcenti.a(crv_nodal_interval_min_and_max.c.o)
has no symbols /usr/bin/ranlib: file:
lib/libcenti.a(crv_remove_all_nodes.c.o)
has no symbols /usr/bin/ranlib: file:
lib/libcenti.a(crv_reset_nodal_forces.c.o)
has no symbols /usr/bin/ranlib: file:
lib/libcenti.a(crv_set_center_coords.c.o)
has no symbols /usr/bin/ranlib: file:
lib/libcenti.a(crv_set_left_ptch_rgn_pixs.c.o)
has no symbols /usr/bin/ranlib: file:
lib/libcenti.a(crv_set_out_rgn_mean_and_var.c.o)
has no symbols /usr/bin/ranlib: file:
lib/libcenti.a(crv_set_para.c.o) has
no symbols /usr/bin/ranlib: file:
lib/libcenti.a(crv_set_right_ptch_rgn_pixs.c.o)
has no symbols /usr/bin/ranlib: file:
lib/libcenti.a(crv_to_in_rgn_hist.c.o)
has no symbols /usr/bin/ranlib: file:
lib/libcenti.a(crv_to_out_rgn_pixs.c.o)
has no symbols /usr/bin/ranlib: file:
lib/libcenti.a(trnk_initialize_by_circle.c.o)
has no symbols /usr/bin/ranlib: file:
lib/libcenti.a(trnk_initialize_by_image_frame.c.o)
has no symbols /usr/bin/ranlib: file:
lib/libcenti.a(trnk_stk_paint_nodes_and_pixs.c.o)
has no symbols /usr/bin/ranlib: file:
lib/libcenti.a(trnk_stk_to_inner_defl_ordn.c.o)
has no symbols

But when I link above library with my application, it gives "Undefined symbols" errors:

Undefined symbols:  
"_setActiveDrawingTrunk", referenced
from:
      RzPluginAlgoCnty::initCallBacks()     
in RzPluginAlgoCnty.cpp.o
      RzPluginAlgoCnty::clearCallBacks()    
in RzPluginAlgoCnty.cpp.o
      _trnk_trck_ordn in libcenti.a(trnk_trck_ordn.c.o)
      _trnk_trck_ordn in libcenti.a(trnk_trck_ordn.c.o)
      _trnk_trck_ordn in libcenti.a(trnk_trck_ordn.c.o)
      _trnk_trck_ordn in libcenti.a(trnk_trck_ordn.c.o)
      _bg_trnk_trck_ordn in libcenti.a(trnk_trck_ordn.c.o)
      _bg_trnk_trck_ordn in libcenti.a(trnk_trck_ordn.c.o)
      _extract_contour_update_tracking in
libcenti.a(extract_contour_update_tracking.c.o)
      _extract_contour_update_tracking in
libcenti.a(extract_contour_update_tracking.c.o)
"_updateCurveUICallBack", referenced
from:
      RzPluginAlgoCnty::initCallBacks()     
in RzPluginAlgoCnty.cpp.o
      RzPluginAlgoCnty::initBulkCallBacks() 
in RzPluginAlgoCnty.cpp.o
      RzPluginAlgoCnty::clearCallBacks()    
in RzPluginAlgoCnty.cpp.o
      _bg_trnk_trck_ordn in libcenti.a(trnk_trck_ordn.c.o)
      _bg_trnk_trck_ordn in libcenti.a(trnk_trck_ordn.c.o)
      _crv_update_1time in libcenti.a(crv_update_ordn.c.o)
      _crv_update_1time in libcenti.a(crv_update_ordn.c.o) ld:
symbol(s) not found

Any tips ? Should I add any special parameters when building static libraries on Mac?

EDIT: I compiled the library as a SHARED library and it worked fine!!

Answer 1

Unfortunately, setting -no_warning_for_no_symbols may not be enough. The ar command on the Mac will run ranlib for you, which causes the "has no symbols /usr/bin/ranlib" message to be displayed. You can stop this message on the Mac by using the following CMake rules:

SET(CMAKE_C_ARCHIVE_CREATE   "<CMAKE_AR> Scr <TARGET> <LINK_FLAGS> <OBJECTS>")
SET(CMAKE_CXX_ARCHIVE_CREATE "<CMAKE_AR> Scr <TARGET> <LINK_FLAGS> <OBJECTS>")
SET(CMAKE_C_ARCHIVE_FINISH   "<CMAKE_RANLIB> -no_warning_for_no_symbols -c <TARGET>")
SET(CMAKE_CXX_ARCHIVE_FINISH "<CMAKE_RANLIB> -no_warning_for_no_symbols -c <TARGET>")

The ARCHIVE_CREATE "Scr" setting will keep ar from running ranlib for you. The ARCHIVE_FINISH setting will gag ranlib from complaining about missing symbols.

You need to use both sets of rules to gag "no symbols" message.

One more thing for CMake newbies: The commands CMake generates for the ar and ranlib commands are dumped into a link.txt file. If you're having problems generating archives, you may want to look at link.txt to see what CMake is doing for you.