I am working recycling a project of my own than works.
The new project
is similar in 60% of the old one. Several classes
files are used with
out any change. Other ones have been created and
proved.
Note.
I am using PNGwriter library with freetype options (in
old and new
projects)
I only have *.c and *.h files extensions in my
proyect.
With the old proyect I used for compilation:
$g ./prueba.cc -o prueba `freetype-config --cflags`
-I/usr/local/include -L/usr/local/lib -lpng
-lpngwriter -lz -lfreetype
The same I am using to the new one until de "undefined
reference to
<function name> problem appears.
I am trying with your ideas, but I can not solve the
problem.
I proved with
$gcc -c *.cc `freetype-config --cflags`
$gcc <list of *.o> -o prueba `freetype-config
--cflags`
-I/usr/local/include -L/usr/local/lib -lpng
-lpngwriter -lz -lfreetype
Compilation works, but linking no. The same error
messagge from the
direct command.
I was looking solutions from google, google groups, I
was commented
several parts of the crucial files but anything works.
I prove with the
simple main.cc, foo.c and foo.h example and I realize
the same problem
is given so the problem is complex for me.
Why the solution should be change the compilation
command? Why if it
works before?
Is it possible than my compiler files were damaged?
Why similar projects have different behavior?
Thanks for your help.
John Love-Jensen escribió:
> Hi Ramirez,
>
>> What is the order criteria?
>
> The GCC tool chain driver processes items left to
right.
>
> Object files (or source files which compile to
object files) are always
> taken in their entirety.
>
> Archive libraries only bring in the objects from
within the archive that
> satisfy missing symbols.
>
> If archive libfoo.a has undefined symbols that are
satisfied in libbar.a,
> then libbar.a needs to appear after libfoo.a.
Regardless if they are
> specified via -lfoo -lbar, or libfoo.a libbar.a or
-lfoo libbar.a or
> libfoo.a -libbar.a.
>
> Shared object libraries are brought in as SSO
(static shared object) as
> specified on the command line. An SSO may have its
own dependencies.
NOTE:
> if you bring in a shared object library
programmatically, that's called a
> DSO (dynamic shared object).
>
> There are some situations where there is both a
libfoo.a and
libfoo.so. If
> left to -lfoo to resolve, the one that is brought
in is dependent on your
> particular platform and if you overrode the
platform bias.
>
> Note: I'm using "libfoo.a" and "libfoo.so", but
you may have a platform
> like the Amiga that uses "foo.a" and "foo.library",
or Windows which uses
> "foo.lib" and "foo.dll", or OS X which uses
"libfoo.a" and
"libfoo.dylib".
> So your mileage may vary.
>
> The rule of thumb is:
> specify all your .o files first (in any order)
> specify all your .a and .so libraries in their
dependency order
>
> And if you are running into a circular dependency
between libfoo.a and
> libbar.a, you'll have to do something utterly
horrible like...
>
> g -o myapp one.o two.o three.o -lfoo -lbar -lfoo
>
> HTH,
> --Eljay
>
>
>
Gengis Kanhg Toledo Ramirez escribió:
> Thanks, it works.
>
> The simple example was only a sample from the real
problem I have.
> I have 10 .cc files and other amount of .h files, I
realize that order
> of files is important at the g command. In my OOP
project I have some
> files as my own libraries used in several others
files, then it is not
> clear for me the order to be followed.
>
> What is the order criteria?
> Where can I get information about?
>
> Thanks you very much.
>
>
> John Love-Jensen escribió:
>> Hi Ramirez,
>>
>> Try this:
>>
>> g main.cc foo.cc -o prueba
>>
>> HTH,
>> --Eljay
>>
>>
>>
>
> The problem:
>
> $ more *.cc *.h
> ::::::::::::::
> foo.cc
> ::::::::::::::
> #include "foo.h"
>
> int foo()
> {
> return 42;
> }
> ::::::::::::::
> main.cc
> ::::::::::::::
> #include "foo.h"
>
> int main()
> {
> return foo();
> }
> ::::::::::::::
> foo.h
> ::::::::::::::
> int foo();
>
> $ g ./main.cc -o prueba
> /home/<myname>/tmp/ccEOfejM.o(.text 0x11): In
function `main':
> : undefined reference to `foo()'
> collect2: ld returned 1 exit status
>
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