GCC --enable-auto-import problem

[Huang Bambo]

1. download db-4.7.25 from oracle at
http://www.oracle.com/database/berkeley-db/index.html (havn't tested
on other version)
2. configure like : ../dist/configure --prefix=/home/Bambo/db-for-1.7
--enable-cxx --enable-pthread_api
3. make, it will take you a few minutes
4. write a program like :
#include <db_cxx.h>

int main( void )
{
       Db db( NULL, 0 );
       return 0;
}

5.compile like :g++ -o t test.cpp -L/home/Bambo/db-for-1.7/lib
-ldb_cxx -I/home/Bambo/db-for-1.7/include
will compile and link ok with information:
Info: resolving typeinfo for std::exception by linking to
__imp___ZTISt9exception (auto-import)
/usr/lib/gcc/i686-pc-cygwin/4.3.2/../../../../i686-pc-cygwin/bin/ld:
warning: auto-importing has been activated without
--enable-auto-import specified on the command line.
This should work unless it involves constant data structures
referencing symbols from auto-imported DLLs.

and the file t.exe can't run, direct run in windows command shell will
report "can't load" with error code 0x00000005.
( use:"ldd t.exe" to find dlls used by the file will hung ldd)

6.compile like:g++ -o t test.cpp -L/home/Bambo/db-for-1.7/lib -ldb_cxx
-I/home/Bambo/db-for-1.7/include -Wl,--enable-auto-import
Then everything goes fine.
ldd t.exe will report:

$ ldd t.exe
       ntdll.dll => /cygdrive/c/WINDOWS/system32/ntdll.dll (0x7c920000)
       kernel32.dll => /cygdrive/c/WINDOWS/system32/kernel32.dll (0x7c800000)
       cygwin1.dll => /usr/bin/cygwin1.dll (0x61000000)
       ADVAPI32.DLL => /cygdrive/c/WINDOWS/system32/ADVAPI32.DLL (0x77da0000)
       RPCRT4.dll => /cygdrive/c/WINDOWS/system32/RPCRT4.dll (0x77e50000)
       Secur32.dll => /cygdrive/c/WINDOWS/system32/Secur32.dll (0x77fc0000)
       cyggcc_s-1.dll => /usr/bin/cyggcc_s-1.dll (0x67f00000)
       cygstdc++-6.dll => /usr/bin/cygstdc++-6.dll (0x6c480000)


Who can tell me why??? Everything goes fine under cygwin 1.5 with gcc
3, gcc4 not tested, even
without "-Wl,--enable-auto-import"