为ubuntu编写cygwin makefile

Question

I am trying to compile the open-source AAM-library. I have tried in Visual Studio, and although it compiled, it had a run-time error. Now I'm trying to compile it in Ubuntu 11.04 using G++. The only makefile provided is a cygwin makefile. I am trying to use this to compile in Ubuntu. (I have included the makefile below). The problem I am having is near the bottom in the lines:

libaamlibrary.dll.a: $(OBJS)
        g++ -fPIC -shared $(OBJS) $(LIBS) -o cygaamlibrary-2.dll -Wl,--enable-auto-image-base -Xlinker --out-implib -Xlinker libaamlibrary.dll.a

"--enable-auto-image-base" is not a recognised option. I am trying to rewrite these 3 lines to a form that does the same thing but works in Ubuntu, but I am struggling, because I don't really understand what the lines are doing (eg, I don't understand Xlinker and how it should be used). Any advice would be much appreciated... Here is the full makefile for reference:

CPPFLAGS = -I. -I/home/andrew/MscProject/OpenCV-2.3.0/include/opencv -O2 -Wall -g -MD -fPIC
PROGRAMS = libaamlibrary.dll.a  libaamlibrary.a fit build 
LIBS = -L/usr/local/lib -lopencv_core -lopencv_imgproc -lopencv_highgui -lopencv_ml -lopencv_video -lopencv_features2d -lopencv_calib3d -lopencv_objdetect -lopencv_contrib -lopencv_legacy -lopencv_flann  
OBJS = AAM_Util.o VJfacedetect.o AAM_Shape.o AAM_CAM.o AAM_PAW.o AAM_PDM.o AAM_TDM.o AAM_MovieAVI.o AAM_Basic.o AAM_IC.o

all: $(PROGRAMS)

AAM_Util.o: AAM_Util.cpp AAM_Util.h 
    g++  $(CPPFLAGS)  -c -o AAM_Util.o AAM_Util.cpp

AAM_Shape.o: AAM_Shape.cpp AAM_Shape.h
    g++  $(CPPFLAGS)  -c -o AAM_Shape.o AAM_Shape.cpp

AAM_TDM.o: AAM_TDM.cpp AAM_TDM.h 
    g++  $(CPPFLAGS)  -c -o AAM_TDM.o AAM_TDM.cpp

AAM_PDM.o: AAM_PDM.cpp AAM_PDM.h 
    g++  $(CPPFLAGS)  -c -o AAM_PDM.o AAM_PDM.cpp

AAM_PAW.o: AAM_PAW.cpp AAM_PAW.h
    g++  $(CPPFLAGS)  -c -o AAM_PAW.o AAM_PAW.cpp

AAM_CAM.o: AAM_CAM.cpp AAM_CAM.h 
    g++  $(CPPFLAGS)  -c -o AAM_CAM.o AAM_CAM.cpp

VJfacedetect.o: VJfacedetect.cpp VJfacedetect.h 
    g++  $(CPPFLAGS)  -c -o VJfacedetect.o VJfacedetect.cpp

AAM_MovieAVI.o: AAM_MovieAVI.cpp AAM_MovieAVI.h
    g++  $(CPPFLAGS)  -c -o AAM_MovieAVI.o AAM_MovieAVI.cpp

AAM_Basic.o: AAM_Basic.cpp AAM_Basic.h
    g++  $(CPPFLAGS)  -c -o AAM_Basic.o AAM_Basic.cpp

AAM_IC.o: AAM_IC.cpp AAM_IC.h 
    g++  $(CPPFLAGS)  -c -o AAM_IC.o AAM_IC.cpp

demo_build.o: train.cpp
    g++  $(CPPFLAGS)  -c -o demo_build.o train.cpp

demo_fit.o: fit.cpp
    g++  $(CPPFLAGS)  -c -o demo_fit.o fit.cpp

libaamlibrary.a: $(OBJS) 
    ar cru libaamlibrary.a $(OBJS)
    ranlib libaamlibrary.a

libaamlibrary.dll.a: $(OBJS)
    g++ -fPIC -shared $(OBJS) $(LIBS) -o cygaamlibrary-2.dll -Wl,--enable-auto-image-base -Xlinker --out-implib -Xlinker libaamlibrary.dll.a

fit: demo_fit.o
    g++ -o fit demo_fit.o libaamlibrary.dll.a $(LIBS) 

build: demo_build.o
    g++ -o build demo_build.o libaamlibrary.dll.a $(LIBS)

clean:
    rm -f *.o $(PROGRAMS)

Answer 1

Practical approach: first try building without all the .dll and .dll.a stuff; just remove the lines that refer to such targets.

It seems .dll.a files are static archives containing position-independent code (PIC), which are necessary in advanced linking scenarios, ie if you're developing shared libraries yourself. (Even if you want such a thing, you shouldn't call it .dll.a on Linux.)

Answer 2

I agree that you should not use a .dll.a or .dll extension (I believe .a and .so are appropriate), but it seems you can't do without libaamlibrary[.dll].a.

Since '--enable-auto-image-base' is prefixed with -Wl, this makes it a linker (ld) option.

I searched 'man ld' and came up with this:

--enable-auto-image-base Automatically choose the image base for DLLs, unless one is specified using the "--image-base" argument. By using a hash generated from the dllname to create unique image bases for each DLL, in-memory collisions and relocations which can delay program execution are avoided. [This option is specific to the i386 PE targeted port of the linker]

What is your platform? It is not available to non i386 architectures as I understand, and maybe not needed? So can you try compiling without it?

By the way I recommend using the excellent Autotools package (automake/autoconf/libtool).

Regarding --out-implib it is also not available on amd64.

--out-implib file The linker will create the file file which will contain an import lib corresponding to the DLL the linker is generating. This import lib (which should be called " .dll.a" or " .a" may be used to link clients against the generated DLL; this behaviour makes it possible to skip a separate "dlltool" import library creation step. [This option is specific to the i386 PE targeted port of the linker]

Sorry but I don't know what an import lib is.