Re: Dynamic libraries

[hjl at lucon dot org (H.J. Lu)]

> 
> 
> Hello All.
> 
> I'm using RedHat5.0, glibc & binutils updated and EGCS-1.0.3.
> I wrote a tiny C++ program that simply loads a (C++) dynamic library,
> calls a function and unloads it. The problem is that if an exception
> is thrown inside the library (and caught there) the program aborts.
> The output is:
> 
> [alfa:~/tmp] app
> Abort
> 
> In particular, if I comment out the "throw" line in the lib, everything
> works well. Does somebody knows what's going on? Since I have no idea
> about it, maybe I'm sending this to the wrong list--excuse me for that.
> 

I have no problems with egcs 1.0.3 on RedHat 5.1. I don't
think Redhat 5.0 should be different.

> Please, c.c. the answer to me because I'm not a list member.
> 
> Code for both files follows, app.cpp is the application and lib.cpp is
> the dynamic library.
> 
> Thank you very much,
> -- Cassino
> 
> --- app.cpp --------------------------------------
> 
> #include <stdio.h>
> #include <dlfcn.h>
> 
> int main(int argc, char **argv)
> {
>   void* lib = dlopen("./liblib.so", RTLD_NOW);
>   if (!lib)
>   {
>     printf("DLFCN error: %s\n", dlerror());
>     return 1;
>   }
>   void* f = dlsym(lib, "f");
>   if (!f)
>   {
>     printf("DLFCN error: %s\n", dlerror());
>     return 2;
>   }
>   ((void(*)(void))f)();
>   dlclose(lib);
>   return 0;
> }
> 
> --- lib.cpp --------------------------------------
> 
> class Except
> {
>   public:
>     int code; 
>     Except(int c) : code(c) { }
> };
> 
> static void g()
> {
>   throw Except(1);
> }
> 
> void cpp_f()
> {
>   try {
>     g();
>   } catch (Except& ex) {
>   }
> }
> 
> extern "C" {
> void f(void)
> {
>   cpp_f();
> }
> }
> 
> 


-- 
H.J. Lu (hjl@gnu.org)