On 05/15/2012 12:14 AM, Alex Rønne Petersen wrote:
On 14-05-2012 23:59, Timon Gehr wrote:
On 05/13/2012 06:13 PM, Alex Rønne Petersen wrote:
Hi,
If memory serves me right, there were some proposals in the past to add
a @noreturn attribute to the language. Where did this go?
In writing unwinding mechanisms for my VM, I find myself actually
needing some sort of @noreturn function attribute that would tell the
compiler that the function does not return, rather than having to insert
an assert(false); statement.
What about making the compiler detect this pattern instead of adding an
attribute? I think it expresses exactly what you want to express, and it
does not require additional syntax.
void foo()out{ assert(false); }body{ ... }
While that might be an easier way to do it, I'm not sure if that would
have unintended side-effects (admittedly, I can't think of any upfront).
Side effects:
- You wouldn't have to add the (completely redundant) assert(false) to
the call site anymore.
- Ideally, the compiler will then optimize the code based on the
pattern, namely, assertions that are unchecked in release mode. That may
or may not be desirable.
=> Fix: Add 'hlt' to end of each method that has assert(false) out in
release mode, and ban return statements from its body.
I think it could go either way, but having both @noreturn and out{
assert(false); } seems somewhat redundant to me.
