The MIPSpro C++ compiler defaults to having exceptions enabled in n32 mode, and disabled in o32 mode. The compiler option to control this is -LANG:exceptions= (ON|OFF) . Also, configure.in:2790 has a check for C++ exceptions commented out, waiting for "some artificial intelligence to detect not only if the compiler has exceptions, but if they are enabled as well." MIPSpro has such artificial intelligence ... The feature macro __EXCEPTIONS can be used in #ifdefs to do conditional compilation based on whether or not this option is enabled. And trying this on g++ works as well.

AI to the rescue. % cat hello.c #ifdef __EXCEPTIONS #error exceptions are enabled #else #error exceptions are not enabled #endif % CC -o hello -c hello.c cc-1035 CC: WARNING File = hello.c, Line = 3 #error directive: exceptions are enabled #error exceptions are enabled ^ % g++ -o hello -c hello.c hello.c:3: #error exceptions are enabled %

r=cls

a= asa@mozilla.org for checkin to the trunk. (on behalf of drivers)

Patch (with slight mod to handle !GNU && !MIPSPRO case) has been checked in.