Repository navigation
Implement fail as a macro/library function #2232
Description
It will not be difficult to eliminate fail from the language, but there are some considerations: a) it has to work with or without an argument (we could just have two); b) in the future it will probably need to accept any sendable type argument, not just a string; c) it has to report the correct location of the error.
Activity
nikomatsakis commentedon Apr 17, 2012
(c) seems to argue for a macro. The macro could also address (a) without requiring two distinct forms. (b) seems easy enough to solve using generic types.
catamorphism commentedon Apr 19, 2012
I opened an issue - #2245 - for the #file and #line macros that we need for this.
kud1ing commentedon May 24, 2012
#2245 is implemented now
eholk commentedon May 25, 2012
I thought another key feature of fail was that typestate knew it never returned and could stop checking after branches that fail. Can we do that with a macro?
brson commentedon May 26, 2012
eholk: we also have the '!' return type that gives us the same information, so we can presumably declare in intrinsic that returns
!eholk commentedon May 26, 2012
Oh right, I forgot about that.
bblum commentedon Jul 18, 2012
With this issue, do we intend to tear out the unwinding bits in the runtime, too? Or just have it call into task::fail which calls rustrt::rust_task_fail?
elliottslaughter commentedon Jul 23, 2012
This has been (partially) implemented in de82a9b, although the current version is a very thin wrapper around the C runtime.
Eventually (i.e. when I finish GC), the GC will handle running any destructors on the stack, making unwinding unnecessary. I've got a partial patch at https://github.com/elliottslaughter/rust/commits/unique-ptrs, but it doesn't yet know about non-pointer resources on the stack.
elliottslaughter commentedon Jul 23, 2012
This issue seems like a subset of #2861, yes?
Edit: No, actually. This involves language changes, whereas #2861 is only concerned with the runtime implementation.
z0w0 commentedon Feb 16, 2013
I think this is done now.
catamorphism commentedon Feb 16, 2013
Done as of 172c29f
Auto merge of rust-lang#2232 - rust-lang:gesundheit, r=oli-obk
Enable build cache in `cargo kani` (rust-lang#2232)
Merge pull request rust-lang#2232 from yegeunyang/rust-lang#2114
Merge rust-lang#2232