Arguably these could become custom queries, but I chose not to do that
because the relationship of queries and trait system is not yet fleshed
out enough. For now it seems fine to have them be `DepTrackingMap` using
the memoize pattern.
The symbol map is not good for incremental: it has inputs from every fn
in existence, and it will change if anything changes. One could imagine
cheating with the symbol-map and exempting it from the usual dependency
tracking, since the results are fully deterministic. Instead, I opted to
just add a per-CGU cache, on the premise that recomputing some symbol
names is not going to be so very expensive.
This may seem like overkill, but it's exactly what we want/need for
incremental compilation I think. In particular, while generating code
for some codegen unit X, we can wind up querying about any number of
external items, and we only want to be forced to rebuild X is some of
those changed from a foreign item to otherwise. Factoring this into a
query means we would re-run only if some `false` became `true` (or vice
versa).
rustc: replace TypeContents with two independent properties (is_freeze / needs_drop).
`InteriorUnsafe` / `interior_unsafe` was replaced with a private lang-item `Freeze` auto trait in libcore.
`OwnsDtor` / `needs_drop` was replaced with a specialized traversal that *doesn't* avoid caching results in case of a cycle, as the only cycles left can only occur in erroneous "types with infinite sizes", references and raw pointers not having destructors. Also, `Copy` is now checked at every step of the recursion.
r? @nikomatsakis
Expanded docs and examples for PathBuf::file_name and friends
This addresses some common surprises when `PathBuf::set_file_name` is called on the path of a directory rather than a file.
r? @steveklabnik
Use an (over-writable) environment variable for the `gdb` command
Instead of hard-coding the command to run, using the environment
variable `GDB_CMD` (that defaults to `gdb`) allows using a different
debugger than the default `gdb` executable.
This gives the possibility to use `cgdb` as the debugger, which provides
a nicer user interface. Note that one has to use `GDB_CMD="cgdb --"` to
use cgdb (note the trailing `--`) to let cgdb pass the proper arguments
to `gdb`.
Reduce visual clutter of multiline start when possible
When a span starts on a line with nothing but whitespace to the left,
and there are no other annotations in that line, simplify the visual
representation of the span.
Go from:
```rust
error[E0072]: recursive type `A` has infinite size
--> file2.rs:1:1
|
1 | struct A {
| _^ starting here...
2 | | a: A,
3 | | }
| |_^ ...ending here: recursive type has infinite size
|
```
To:
```rust
error[E0072]: recursive type `A` has infinite size
--> file2.rs:1:1
|
1 | / struct A {
2 | | a: A,
3 | | }
| |_^ recursive type has infinite size
```
Re: #38246.
r? @nikomatsakis CC @jonathandturner
When a span starts on a line with nothing but whitespace to the left,
and there are no other annotations in that line, simplify the visual
representation of the span.
Go from:
```rust
error[E0072]: recursive type `A` has infinite size
--> file2.rs:1:1
|
1 | struct A {
| _^ starting here...
2 | | a: A,
3 | | }
| |_^ ...ending here: recursive type has infinite size
|
```
To:
```rust
error[E0072]: recursive type `A` has infinite size
--> file2.rs:1:1
|
1 | / struct A {
2 | | a: A,
3 | | }
| |_^ recursive type has infinite size
```
Remove `starting here...`/`...ending here` labels from all multiline
diagnostics.
The main changes around rustc::ty::Layout::struct and rustc_trans:adt:
* Added primitive_align field which stores alignment before repr align
* Always emit field padding when generating the LLVM struct fields
* Added methods for adjusting field indexes from the layout index to the
LLVM struct field index
The main user of this information is rustc_trans::adt::struct_llfields
which determines the LLVM fields to be used by LLVM, including padding
fields.
Update `Child` docs to not have a note section
In #29370 it's noted that for "the Note shouldn't be one, and should come before
the examples." This commit changes the positioning of the section and removes
wording that said take note in order for it to flow better with the surrounding
text and it's new position.
specialize Extend for Vec with IntoIter
Before, `vec.extend(&other_vec)` was quite a bit faster than `vec.extend(other_vec)`. This allows extending by consuming a vec to use the same code as extending from a slice.
