Implement Error trait for fmt::Error type
Fixes#33827.
r? @alexcrichton
Just one last thing: I added a feature name, but don't hesitate to ask me to change it if you think it doesn't fit well.
Apply visit_path to import prefixes by default
Overriding `visit_path` is not enough to visit all paths, some import prefixes are not visited and `visit_path_list_item` need to be overridden as well. This PR removes this catch, it should be less error prone this way. Also, the prefix is visited once now, not repeatedly for each path list item.
r? @eddyb
refactor autoderef to avoid prematurely registering obligations
Refactor `FnCtxt::autoderef` to use an external iterator and to not
register any obligation from the main autoderef loop, but rather to
register them after (and if) the loop successfully completes.
Fixes#24819Fixes#25801Fixes#27631Fixes#31258Fixes#31964Fixes#32320Fixes#33515Fixes#33755
r? @eddyb
Implement `count` for `EscapeUnicode`
and cleanup the code for `count` for `EscapeDefault` (instead of repeating the `match` for `size_hint` and `count`).
This PR marks EscapeUnicode and EscapeDefault as ExactSizeIterator. The constraints for the trait implementations held even before this PR, but I am not sure if this is something we want to guarantee/expose (I would love feedback on this, especially on what would be the appropriate way to handle stabilisation, if needed).
Part of #24214, split from #31049.
The test for `count` was added in #33103.
std: Use memalign, not posix_memalign, on Android
We've gotten requests to move our Android support as far back as API level 9
where unfortunately the `posix_memalign` API wasn't implemented yet. Thankfully,
however, the `memalign` API was and it appears to be usable with `free` on the
Android platform (see comments included in commit).
This should help fix some of the last few test failures when compiling against
API level 9.
panic.rs: fix docs (recover -> catch_unwind)
The current docs are a bit inconsistent. First, change all references of "recover" to "catch_unwind" because the function was renamed. Second, consistently use the term "unwind safe" instead of "panic safe", "exception safe" and "recover safe" (all these terms were used previously).
Increase spacing in error format for readability.
Two small tweaks that seem to help readability quite a bit:
* Add spacing header<->snippet, but use the |> on the side for visual consistency
* Fix#33819
* Fix#33763
* Move format-sensitive test (issue-26480 in cfail) to ui test
r? @nikomatsakis
Perform `cfg` attribute processing during macro expansion and fix bugs
This PR refactors `cfg` attribute processing and fixes bugs. More specifically:
- It merges gated feature checking for stmt/expr attributes, `cfg_attr` processing, and `cfg` processing into a single fold.
- This allows feature gated `cfg` variables to be used in `cfg_attr` on unconfigured items. All other feature gated attributes can already be used on unconfigured items.
- It performs `cfg` attribute processing during macro expansion instead of after expansion so that macro-expanded items are configured the same as ordinary items. In particular, to match their non-expanded counterparts,
- macro-expanded unconfigured macro invocations are no longer expanded,
- macro-expanded unconfigured macro definitions are no longer usable, and
- feature gated `cfg` variables on macro-expanded macro definitions/invocations are now errors.
This is a [breaking-change]. For example, the following would break:
```rust
macro_rules! m {
() => {
#[cfg(attr)]
macro_rules! foo { () => {} }
foo!(); // This will be an error
macro_rules! bar { () => { fn f() {} } }
#[cfg(attr)] bar!(); // This will no longer be expanded ...
fn g() { f(); } // ... so that `f` will be unresolved.
#[cfg(target_thread_local)] // This will be a gated feature error
macro_rules! baz { () => {} }
}
}
m!();
```
r? @nrc
Fix misleading intentation errors on gcc 6.0
Currently building with latest gcc results in the following error:
compile: x86_64-unknown-linux-gnu/rt/miniz.o
/home/lc/rust/src/rt/miniz.c: In function ‘tinfl_decompress’:
/home/lc/rust/src/rt/miniz.c:578:9: error: this ‘for’ clause does not guard... [-Werror=misleading-indentation]
for ( i = 0; i <= 143; ++i) *p++ = 8; for ( ; i <= 255; ++i) *p++ = 9; for ( ; i <= 279; ++i) *p++ = 7; for ( ; i <= 287; ++i) *p++ = 8;
^~~
/home/lc/rust/src/rt/miniz.c:578:47: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the ‘for’
for ( i = 0; i <= 143; ++i) *p++ = 8; for ( ; i <= 255; ++i) *p++ = 9; for ( ; i <= 279; ++i) *p++ = 7; for ( ; i <= 287; ++i) *p++ = 8;
^~~
/home/lc/rust/src/rt/miniz.c: In function ‘tdefl_find_match’:
/home/lc/rust/src/rt/miniz.c:1396:5: error: this ‘if’ clause does not guard... [-Werror=misleading-indentation]
if (!dist) break; p = s; q = d->m_dict + probe_pos; for (probe_len = 0; probe_len < max_match_len; probe_len++) if (*p++ != *q++) break;
^~
/home/lc/rust/src/rt/miniz.c:1396:23: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the ‘if’
if (!dist) break; p = s; q = d->m_dict + probe_pos; for (probe_len = 0; probe_len < max_match_len; probe_len++) if (*p++ != *q++) break;
^
This patch stops this.
Add `make tips` as useful make target
By accident, I found the `make tips` target, which helped me to gain more insight on how to work with the system more quickly.
Trait documentation clarifications
Hi! I've felt a bit of friction lately in figuring out how to write custom implementations of the `derive`able traits, so I decided to add to the docs :)
The docs for `Copy` are already excellent-- clear, useful sections that I only reordered a bit-- they're now:
* General explanation
* When can my type be `Copy`?
* When can my type _not_ be `Copy`?
* When should my type be `Copy`?
* Derivable
* How can I implement `Copy`?
I didn't add all these sections for all the traits, but I did make sure all the derivable traits had a consistent "Derivable" section that explained what the derived implementation does and a "How can I implement" section that has an example.
Please check me for correctness-- I tried to do research to make sure I was saying accurate things but I'm still learning! ❤️ I'd also love suggestions on information to add that is still missing-- I think these traits are important and deserve to have awesome docs!
Fix `asm-misplaced-option` on ARM/AArch64
This fixesrust-lang/rust#33737. Of course, since we don't run `make check` for ARM cross builds, you probably won't notice it.
This makes the \"shadowing labels\" warning *not* print the entire loop as a span, but only the lifetime.
Also makes #31719 go away, but does not fix its root cause (the span of the expanded loop is still wonky, but not used anymore).
Fix handling of FFI arguments
r? @eddyb @nikomatsakis or whoever else.
cc @alexcrichton @rust-lang/core
The strategy employed here was to essentially change code we generate from
```llvm
%s = alloca %S ; potentially smaller than argument, but never larger
%1 = bitcast %S* %s to { i64, i64 }*
store { i64, i64 } %0, { i64, i64 }* %1, align 4
```
to
```llvm
%1 = alloca { i64, i64 } ; the copy of argument itself
store { i64, i64 } %0, { i64, i64 }* %1, align 4
%s = bitcast { i64, i64 }* %1 to %S* ; potentially truncate by casting to a pointer of smaller type.
```
