rust/library
Dylan DPC 4bd40186db
Rollup merge of #97321 - RalfJung:int-to-fnptr, r=Dylan-DPC
explain how to turn integers into fn ptrs

(with an intermediate raw ptr, not a direct transmute)
Direct int2ptr transmute, under the semantics I am imagining, will produce a ptr with "invalid" provenance that is invalid to deref or call. We cannot give it the same semantics as int2ptr casts since those do [something complicated](https://www.ralfj.de/blog/2022/04/11/provenance-exposed.html).

To my great surprise, that is already what the example in the `transmute` docs does. :)  I still added a comment to say that that part is important, and I added a section explicitly talking about this to the `fn()` type docs.

With https://github.com/rust-lang/miri/pull/2151, Miri will start complaining about direct int-to-fnptr transmutes (in the sense that it is UB to call the resulting pointer).
2022-05-24 15:58:26 +02:00
..
alloc Rollup merge of #97087 - Nilstrieb:clarify-slice-iteration-order, r=dtolnay 2022-05-23 07:43:49 +02:00
backtrace@b02ed04a7e
core Rollup merge of #97321 - RalfJung:int-to-fnptr, r=Dylan-DPC 2022-05-24 15:58:26 +02:00
panic_abort Use Rust ABI for __rust_start_panic and _{rdl,rg}_oom 2022-05-14 02:53:59 +01:00
panic_unwind Use Rust ABI for __rust_start_panic and _{rdl,rg}_oom 2022-05-14 02:53:59 +01:00
portable-simd portable-simd: use simd_arith_offset to avoid ptr-int transmutation 2022-04-12 11:09:26 -04:00
proc_macro Remove some unnecessary rustc_allow_const_fn_unstable attributes. 2022-05-13 16:01:18 +10:00
profiler_builtins
rtstartup
rustc-std-workspace-alloc
rustc-std-workspace-core
rustc-std-workspace-std
std Rollup merge of #97321 - RalfJung:int-to-fnptr, r=Dylan-DPC 2022-05-24 15:58:26 +02:00
stdarch@28335054b1 Also allow unused macro rules in stdarch 2022-05-10 19:53:22 +02:00
test Auto merge of #95678 - pietroalbini:pa-1.62.0-bootstrap, r=Mark-Simulacrum 2022-04-07 07:34:04 +00:00
unwind Auto merge of #97033 - nbdd0121:unwind3, r=Amanieu 2022-05-19 04:04:40 +00:00