[Bug target/12020] undefined reference in libgcc2.c to __do_global_ctors when testing C compiler

[wilson at specifixinc dot com]

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12020



------- Additional Comments From wilson at specifixinc dot com  2003-10-14 02:22 -------
Subject: Re:  undefined reference in libgcc2.c to __do_global_ctors
 when testing C compiler

pinskia at gcc dot gnu dot org wrote:
> Looks like HAS_INIT_SECTION is defined but INVOKE__main is also defined but the file format is not 
> elf aka OBJECT_FORMAT_ELF is not defined. Could any one comment on what is going on here?

The d30v port has no maintainer, and no known users.  It is likely to be 
  obsoleted the next time we go through that process.  I see no point in 
trying to make it work.

Using ambiguous targets like d30v is a bad idea.  You will match the 
default d30v target for each tool, which could be different, resulting 
in a toolchain that won't work.  I'm guessing that d30v was used as the 
target because config.gcc has "d30v-*-*".  That doesn't mean that it is 
OK to use d30v as the target.  That means that we want all targets to 
use the same gcc configuration.  However, this can't possibly work for 
targets like d30v-coff.  This should be fixed, but since I expect the 
d30v port to be obsoleted, it probably isn't worth fixing.

The file format is ELF.  OBJECT_FORMAT_ELF comes from config/elfos.h.

The problem here seems to be that when the port was written, it didn't 
use the standard ELF conventions for running static constructors.  Some 
embedded ports used the coff conventions because they were simpler to 
get working.  If you look at the libgloss d30v/crt0.S file, you will see 
that there is no support for running code in init/fini sections. 
Rather, we rely on __main to call the function addresses in the 
.ctor/.dtor sections.  Thus the need to define INVOKE__main which is 
normally not used for an ELF target.  This must have worked fine in 1997 
or so when the code was written.  Since then, there have been a lot of 
structural changes, and it happens not to work anymore.  This went 
unnoticed, because there are no users for the d30v port.  The proper fix 
for this is to use ELF style static constructors instead of COFF style, 
which means getting rid of the INVOKE__main definition in gcc, and in 
newlib fixing the libgloss d30v/crt0.S to run code in .init and .fini 
sections.  But since I expect the port to be deprecated soon, I don't 
see the point of doing this work.