rustbuild: Fix a few rebuilding issues
Did a bit of investigation and found a few small unrelated issues, but this should help clean up a lot of errors we've been seeing locally.
Use more specific panic message for &str slicing errors
Separate out of bounds errors from character boundary errors, and print
more details for character boundary errors.
It reports the first error it finds in:
1. begin out of bounds
2. end out of bounds
3. begin <= end violated
3. begin not char boundary
5. end not char boundary.
Example:
&"abcαβγ"[..4]
thread 'str::test_slice_fail_boundary_1' panicked at 'byte index 4 is not
a char boundary; it is inside 'α' (bytes 3..5) of `abcαβγ`'
Fixes#38052
Recent versions of Cargo lift less output up into the "main" directory, so let's
look more inside the `deps` folder for changes to propagate differences.
Closes#38744Closes#38746
Despite what the comment says, we actually need to do this. We're not cleaning
out the stage0 compiler's sysroot, but rather just our own sysroot that we
assembled previously.
Currently, late lint checking uses two HIR visitors: LateContext and
IdVisitor. IdVisitor only overrides visit_id, and for each node searches
for builtin lints previously added to the session; LateContext overrides
a number of methods, and runs late lints. When LateContext encounters an
item, it first has IdVisitor walk everything in it except nested items
(OnlyBodies), then recurses into it itself - i.e. there are two separate
walks.
Aside from apparently being unnecessary, this separation prevents lint
attributes (allow/deny/warn) on non-item HIR nodes from working
properly. Test case:
// generates warning without this change
fn main() { #[allow(unreachable_code)] loop { break; break; } }
LateContext contains logic to merge attributes seen into the current lint
settings while walking (with_lint_attrs), but IdVisitor does not. So
such attributes will affect late lints (because they are called from
LateContext), and if the node contains any items within it, they will
affect builtin lints within those items (because that IdVisitor is run
while LateContext is within the attributed node), but otherwise the
attributes will be ignored for builtin lints.
This change simply removes IdVisitor and moves its visit_id into
LateContext itself. Hopefully this doesn't break anything...
Also added walk calls to visit_lifetime and visit_lifetime_def
respectively, so visit_lifetime_def will recurse into the lifetime and
visit_lifetime will recurse into the name. In principle this could
confuse lint plugins. This is "necessary" because walk_lifetime calls
visit_id on the lifetime; of course, an alternative would be directly
calling visit_id (which would require manually iterating over the
lifetimes in visit_lifetime_def), but that seems less clean.
The `-Wl` option splits its parameters on commas, so if rustc specifies
`-Wl,-rpath,<path>` when `<path>` contains commas, the path gets split up
and the linker gets a partial path and spurious extra parameters.
Gcc/clang support the more verbose `-Xlinker` option to pass options
to the linker directly, so use it for comma-containing paths.
Fixes rust issue #38795.
prefer hyphens in test files named after issue numbers
We have a lot of tests with filenames honoring particular issues by
number. Typically, these are called issue-${issue_no}.rs (note the
hyphen):
```
$ find . -regextype posix-egrep -regex '.*/issue-[0-9]*.rs' | wc
1289 1289 35935
```
We also had a much smaller number of files that are like this, but don't
have a hyphen in between the substring `issue` and the number:
```
$ find . -regextype posix-egrep -regex '.*/issue[0-9]*.rs'
./debuginfo/issue14411.rs
./debuginfo/issue12886.rs
./debuginfo/issue13213.rs
./debuginfo/issue22656.rs
./debuginfo/issue7712.rs
./compile-fail/issue32829.rs
./run-pass/issue24353.rs
./run-pass/issue34796.rs
./run-pass/issue18173.rs
./run-pass/issue22346.rs
./run-pass/auxiliary/issue13507.rs
./run-pass/issue26127.rs
./run-pass/issue22008.rs
./run-pass/issue34569.rs
./run-pass/issue29927.rs
./run-pass/issue36260.rs
```
Some would argue that the inconsistency is æsthetically displeasing,
hence this trivial patch. (Note that run-pass/auxiliary/issue13507.rs
has an excuse; it's `use`d in run-pass/issue-13507-2.rs; the matter of
there being two different compile-fail tests with different name
conventions for issue no. 32829 is also neglected here for the sake of
keeping this trivial cleanup patch as trivial as possible for ease of
review.)
We now cache the inhabitedness of types in the GlobalCtxt.
Rather than calculating whether a type is visibly uninhabited from a given
NodeId we calculate the full set of NodeIds from which a type is visibly
uninhabited then cache that set. We can then use that to answer queries about
the inhabitedness of a type relative to any given node.
Don't warn about dead foreign items if the 'allow(dead_code)' attribute is present
This functionality was missing, and should have existed previously.
Fixes#38780
Fix is_uninhabited for enum types. It used to assume that an enums variant's
fields were all private.
Fix MIR generation for irrefutable Variant pattern matches. This allows code
like this to work:
let x: Result<32, !> = Ok(123);
let Ok(y) = x;
Carry type information on dummy wildcard patterns. Sometimes we need to expand
these patterns into their constructors and we don't want to be expanding a
TyError into a Constructor::Single.
Remove the assumption at the start of is_useful that any suitably-long array of
wildcard patterns is useful relative the any empty vector. Instead we just
continue to recurse column-wise over the matrix.
This assumption is false in the presence of empty types.
eg. in the simplest case:
let x: ! = ...;
match x {
// This pattern should not be considered useful by the algorithm
_ => ...
}
`BoolTrie` works well for sets of code points spread out through
most of Unicode’s range, but is uses a lot of space for sets
with few, mostly low, code points.
This switches a few of its instances to a similar but simpler trie
data structure.
## Before
`size_of::<BoolTrie>()` is 1552, which is added to
`table.r3.len() * 8 + t.r5.len() + t.r6.len() * 8`:
* `Cc_table`: 1632
* `White_Space_table`: 1656
* `Pattern_White_Space_table`: 1640
* Total: 4928 bytes
## After
`size_of::<SmallBoolTrie>()` is 32, which is added to
`t.r1.len() + t.r2.len() * 8`:
* `Cc_table`: 51
* `White_Space_table`: 273
* `Pattern_White_Space_table`: 193
* Total: 517 bytes
## Difference
Every Rust program with `std` statically linked should be about 4 KB smaller.
Fix debuginfo for unsized struct members
The member was given the size of a fat pointer, which caused
llvm to emit DWARF attributes for a 128-bit bitfield.
