[Tinycc-devel] TCC and external variables - am I not seeing something?

[Aleksandar Kuktin]

Hello.

I apologize if I am writing to the wrong list. This is really an issue
for something like tinycc-support, but the TCC website does not list
any such maillist (or have I just gone blind?). If there is, infact,
such a list, please direct me to it so I don't spam the -dev list.

Anyway..

I have a problem with TCC and external variables, and right now I am
not sure if I am the one who is not behaving or if it is an issue with
TCC.

I should probably mention that I have no formal schooling in neither
programming nor anything computer-science related. I am entirely
self-taught and therefore may be missing an obvious thing or two. So
please don't berate me if that's the case. :)

I am currently working on a solo practice project (open-source, but not
yet published) and I have a number of header files which contain global
variables, (some are ints, some are structs) and I access them from
several functions spread over several source files. System is
ELF-Linux-GNU_libc. My problem is that I can not make TCC link the files
into an executable. It complains (excerpt):

obj/daemon.o: error: 'nbworks_errno' defined twice
obj/daemon.o: error: 'nbworks_do_align' defined twice
obj/daemon.o: error: 'nbworks_rootscope' defined twice
obj/library.o: error: 'nbworks_libcntl' defined twice
obj/library.o: error: 'nbworks_errno' defined twice
obj/library.o: error: 'nbworks_do_align' defined twice
obj/library.o: error: 'nbworks_rootscope' defined twice
<<this goes on for quite a while>>

When linking, obj/daemon.o is preceded by obj/api.o which also uses
those three variables. Ditto for obj/library.o and all the other files.

As far as I am able to understand, when I first compile individual
source files into object files, TCC makes a separate copy of all global
variables for each object file. Then, when it tries to link them
together, it apparently sees the same symbol in multiple files,
concludes that there is a definition conflict and aborts.

Did I get this right? Is there a way to force TCC to link the files?

The compiler I normally use is GCC, which has no problems about linking
these files. But, I am seeing some strange bugs and crashes in my
program and am really starting to wonder if it is all GCCs fault. So I
chose to try a different compiler and see if I can reproduce the errors.
Unfortunately, thats when I ran into this. :(

Header files have this:

typedef int nbworks_errno_t;
/*extern*/ nbworks_errno_t nbworks_errno;
typedef unsigned char nbworks_do_align_t;
/*extern*/ nbworks_do_align_t nbworks_do_align;

Source files have this:

struct thread_cache *
  daemon_internal_initializer(struct thread_cache *tcache) {
    extern nbworks_do_align_t nbworks_do_align;
    extern struct nbworks_namsrvc_cntrl_t nbworks_namsrvc_cntrl;
    extern struct nbworks_pruners_cntrl_t nbworks_pruners_cntrl;
    struct thread_cache *result;
    struct rail_params railparams;

    /* blah, blah, blah... */
}

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You don't need an AI for a robot uprising.
Humans will do just fine.
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