handle zero-size allocations correctly #11635

thestinger · 2014-01-18T02:06:32Z

The malloc family of functions may return a null pointer for a
zero-size allocation, which should not be interpreted as an
out-of-memory error.

If the implementation does not return a null pointer, then handling
this will result in memory savings for zero-size types.

This also switches some code to malloc_raw in order to maintain a
centralized point for handling out-of-memory in rt::global_heap.

Closes #11634

alexcrichton · 2014-01-18T02:40:06Z

src/libstd/rt/global_heap.rs

-    if p.is_null() {
-        // we need a non-allocating way to print an error here
-        abort();
+    if size == 0 {


This and the above malloc should probably have comments explaining why they're explicitly checking for the 0-sized case.

The `malloc` family of functions may return a null pointer for a zero-size allocation, which should not be interpreted as an out-of-memory error. If the implementation does not return a null pointer, then handling this will result in memory savings for zero-size types. This also switches some code to `malloc_raw` in order to maintain a centralized point for handling out-of-memory in `rt::global_heap`. Closes #11634

…eykril Generate enum variant assist So, this is kind of a weird PR! I'm a complete newcomer to the `rust-analyzer` codebase, and so I browsed the "good first issue" tag, and found rust-lang#11635. Then I found two separate folks had taken stabs at it, most recently `@maartenflippo` — and there had been a review 3 days ago, but no activity in a little while, and the PR needed to be rebased since the crates were renamed from `snake_case` to `kebab-case`. So to get acquainted with the codebase I typed this PR by hand, looking at the diff in rust-lang#11995, and I also added a doc-test (that passes). I haven't taken into account the comments `@Veykril` left in rust-lang#11995, but I don't want to steal any of `@maartenflippo's` thunder! Closing this PR is perfectly fine. Or Maarten could use it as a "restart point"? Or I could finish it up, whichever feels best to everyone. I think what remains to be done in this PR, at least, is: * [x] Only disable the "generate function" assist if the name is `PascalCase` * [x] Only enable the "generate variant" assistant if the name is `PascalCase` * [x] Simplify with `adt.source()` as mentioned here: rust-lang/rust-analyzer#11995 (comment) * [ ] Add more tests for edge cases? Are there cases where simply adding one more indent level than the enum's indent level is not good enough? Some nested trickery I'm not thinking of right now? Anyway. This PR can go in any direction. You can tell me "no, tackle your own issue!" And I'll go do that and still be happy I got to take a look at rust-analyzer some by doing this. Or you can tell me "okay, now _you_ finish it", and I guess I'll try and finish it :) Closes rust-lang#11635

[`into_iter_without_iter`]: walk up deref impl chain to find `iter` methods Fixes rust-lang#11635 changelog: [`into_iter_without_iter`]: walk up deref impl chain to find `iter` methods

alexcrichton reviewed Jan 18, 2014
View reviewed changes

bors closed this Jan 19, 2014

bors merged commit ae2a5ec into rust-lang:master Jan 19, 2014

thestinger deleted the zero-size-alloc branch February 8, 2014 04:58

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handle zero-size allocations correctly #11635

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thestinger commented Jan 18, 2014

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alexcrichton Jan 18, 2014

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handle zero-size allocations correctly #11635

handle zero-size allocations correctly #11635

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thestinger commented Jan 18, 2014

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