Separate-stage static linking of C or C++ code using -nostdlib

[Amittai Aviram]

Hi!  I need to compile C (or C++) source code to an object file and  
then link it with the appropriate library in two separate stages.   
I've always seen this done (and done it this way myself?) by invoking  
gcc both times. --

gcc -c myfile.c -o myfile.o
gcc myfile.o -o myfile

This works great if I'm using the installed standard libraries and  
include headers.  But now I want to compile a C object file (say) and  
link it against (say) a version of Gnu Glibc that I have downloaded,  
built, and installed into a separate, special directory.  Then, I am  
finding that I have to invoke ld or GCC's helper utility collect2  
rather than gcc itself for the linking stage. --

BASEDIR = /export/home/afa9/Documents/glibc/bin
LIBDIR := $(BASEDIR)/lib
START_FILES := $(LIBDIR)/crt1.o $(LIBDIR)/crti.o /usr/lib/gcc/i586- 
suse-linux/4.3/crtbeginT.o
LINK_LIBS := -L/usr/lib/gcc/i586-suse-linux/4.3 -L/usr/i586-suse-linux/ 
lib -L$(LIBDIR)
GCC_LIBS = --start-group -lgcc -lgcc_eh -lc --end-group
END_FILES :=  /usr/lib/gcc/i586-suse-linux/4.3/crtend.o $(LIBDIR)/crtn.o
LD_OPTIONS := -g -nostdlib -static -m elf_i386
COMP_OPTIONS = -Wall -g -nostdinc
INCLUDES := -I$(BASEDIR)/include -I/usr/lib/gcc/i586-suse-linux/4.3/ 
include \
         -I/usr/lib/gcc/i586-suse-linux/4.3/include-fixed

COLLECT = /usr/lib/gcc/i586-suse-linux/4.3/collect2

hello: hello.o
         ld $(LD_OPTIONS) -o hello $(LINK_LIBS) $(START_FILES) hello.o  
$(END_FILES) $(GCC_LIBS)
	# Also works:  $(COLLECT) $(LD_OPTIONS) -o hello $(LINK_LIBS) $ 
(START_FILES) hello.o $(END_FILES) $(GCC_LIBS)

hello.o: hello.c
         gcc $(COMP_OPTIONS) $(INCLUDES) -c hello.c -o hello.o


If I try to use gcc for the link stage rather than collect2, I get a  
huge bunch of errors, most of which have to do with undefined  
references to _Unwind_Resume, to other routines with names starting  
with "_Unwind," and to __gcc_personality_v0.  Does anybody know why  
this is, and why gcc doesn't just pass the relevant arguments along to  
ld and invoke ld?  I thought that that's what it was supposed to do.

Thanks!




Amittai Aviram
Graduate Student in Computer Science
Yale University
646 483 2639
amittai.aviram@yale.edu
http://www.amittai.com