Language extension for maintenance of legacy application sounds a little bullsh1t to me.
0) If the application needs checks on anything (at the cost of performance) then higher level language (like C++) should be chosen at design time. No use for new application.
1) Existing applications will NOT port directly. Real-life applications are tightly coupled with supported compiler(s), so the compiler would need the update. Errors/exceptions (like overflows) would need handling and changes in logic. It could only deny read/write from illegal area, but without the feedback. The speed is also a major thing. Boundary check could possible prevent some bugs, but the performance will drop dramatically (example: commonly used libs like OpenSSL).
One use case I see is to add an extension (like GCC's for instance) for an existing compiler which does this. User could build a slower debug application and spot the silent errors during testing. An implementation thing, not the language extension.
0) If the application needs checks on anything (at the cost of performance) then higher level language (like C++) should be chosen at design time. No use for new application. 1) Existing applications will NOT port directly. Real-life applications are tightly coupled with supported compiler(s), so the compiler would need the update. Errors/exceptions (like overflows) would need handling and changes in logic. It could only deny read/write from illegal area, but without the feedback. The speed is also a major thing. Boundary check could possible prevent some bugs, but the performance will drop dramatically (example: commonly used libs like OpenSSL).
One use case I see is to add an extension (like GCC's for instance) for an existing compiler which does this. User could build a slower debug application and spot the silent errors during testing. An implementation thing, not the language extension.