Re: add .cc files to libgcc.a

[Perry Smith <pedzsan at gmail dot com>]

On Oct 29, 2012, at 9:32 AM, Jonathan Wakely wrote:

> On Oct 29, 2012 1:54 PM, "Perry Smith" wrote:
>> 
>> My original logic in adding them to libstdc++.a is they are only used (called) by code automatically produced by g++ and not gcc.
> 
> That doesn't make sense. Both gcc and g++ are just driver programs
> that invoke the appropriate compiler program, which for C++ is
> cc1plus. So C++ code can be compiled by gcc, and doesn't necessarily
> link to libstdc++.
> 
> Putting the files in libsupc++ might make sense but libstdc++ is
> definitely wrong.

You've mentioned this before.  I think you are needlessly splitting hairs.  The construct that produces the code that causes the failure is a c++ construct.  The construct that causes the compiler to produce a call to atexit is a static of a variable with a non-trivial destructor declared inside a function.  This program, does not compile with gcc:

> #include <stdio.h>
> 
> class foo {
> private:
>     const char *name;
>     void mess(const char *s) {
>         printf("%s %s\n", s, name);
>     }
> 
> public:
>     foo(const char *s) {
>         name = s;
>         mess("ctor");
>     }
> 
>     ~foo() {
>         mess("dtor");
>     }
> };
> 
> foo& func()
> {
>     static foo val("func");
>     return val;
> }

But it compiles just fine with g++.

For most platforms, the compiler produces a call to __cxa_atexit.  On AIX, because AIX does not have __cxa_atexit natively, the compiler produces a call to atexit.  atexit doesn't really have the smarts required for shared libraries.  I've discussed this all at length before.

Perry