Sounds reasonably simple, thanks for the idea!
On Thu, Jan 1, 2015 at 11:46 AM, Manish Goregaokar <[email protected]>
wrote:
> It should be reasonably easy to write a lint as a compiler plugin such
> that the following function:
>
> #[unsafe_specific]
> unsafe fn foo () {
> #[allowed_unsafe] { // or just #[allow(unsafe_something_something)]
> // do unsafe things here
> }
> // no unsafe blocks or functions allowed here.
> }
>
> would not compile with any unsafe code in the latter half of the function.
>
> Alternatively:
>
> unsafe fn foo() {
> fn bar() {
> unsafe {
> // unsafe stuff here
> }
> // no unsafe stuff here
> }
> bar();
> }
>
> -Manish Goregaokar
>
> On Thu, Jan 1, 2015 at 4:47 PM, Vladimir Pouzanov <[email protected]>
> wrote:
>
>> I had this idea for some time and I'd like to discuss it to see if it is
>> something reasonable to be proposed for rust to implement or there are
>> other ways around the problem.
>>
>> Let's say I have a low level function that manipulates the hardware clock
>> using some platform-specific argument. Internally this function will do an
>> unsafe volatile mem write to store value in the register, but this is the
>> only part of the code that is unsafe compiler-wise, whatever else is in
>> there in the function is safe and I want the compiler to warn me if any
>> other unsafe operation happens.
>>
>> Now, given that this function is actually unsafe in terms of its realtime
>> consequences (it does not do any validation of the input for speed) I want
>> to mark it as unsafe fn and make a safer wrapper for end users, while
>> keeping this for the little subset of users that will need the actual speed
>> benefits.
>>
>> Unfortunately, marking it unsafe will now allow any other unsafe
>> operation in the body of the function, when what I wanted is just to force
>> users of it to be aware of unsafety via compiler validation.
>>
>> A safe {} block could have helped me in this case. But is it a good idea
>> overall?
>>
>> Some pseudo-code to illustrate
>>
>> pub unsafe fn set_clock_mode(mode: uint32) {
>> // ...
>> // doing some required computations
>> // this code must be 'safe' for the compiler
>> unsafe {
>> // ...
>> // writing the value to mmaped register, this one is unsafe but
>> validated by programmer
>> }
>> }
>>
>> pub fn set_clock_mode_safe(mode: uint32) -> bool {
>> // ...
>> // validate input
>> unsafe {
>> // I want this call to require unsafe block
>> set_clock_mode(mode);
>> }
>> }
>>
>> --
>> Sincerely,
>> Vladimir "Farcaller" Pouzanov
>> http://farcaller.net/
>>
>> _______________________________________________
>> Rust-dev mailing list
>> [email protected]
>> https://mail.mozilla.org/listinfo/rust-dev
>>
>>
>
--
Sincerely,
Vladimir "Farcaller" Pouzanov
http://farcaller.net/
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