[rtl] Follow-Up to Constructors/Destructors

[Colin Leister <CLeister@dcaweb.net>]

Hi,

I'm new to using RT-Linux but so far I am extremely pleased with the 
results I have found.

I was reading through the RTL mailing list and found numerous articles 
about C++.  Several of
them mentioned calling constructors and destructors for global objects 
explicitly.  I wanted to add that this is not necessary if you're 
using gcc and only slightly modify your code and your makefile.

In init_module() add a call to __do_global_ctors_aux(), and in 
cleanup_module() add a call to
__do_global_dtors_aux().

In your makefile incorporate these changes:

CRT_BEG=	/the_correct_gcc-lib_path/crtbegin.o
CRT_END=	/the_correct_gcc-lib_path/crtend.o

On the link line that specifies all your object files, in front of the 
first .o file, add ${CRT_BEG}.
After the last .o file, add ${CRT_END}.

e.g.	ld -Ur -static -o module.o ${CRT_BEG} file1.o file2.o file3.o 
${CRT_END}

This enables the linker to collect all constructor/destructor and 
initialization calls into a list that's kept in the initialization 
section.  __do_global_ctors_aux() and __do_global_dtors_aux() use this 
list.

-Colin Leister


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