This reverts commit 3ed3b8bb7b, reversing
changes made to 99b89533d4.
We will reland a similar patch at a future date but for now we should get a nightly
released in a few hours with the parallel patch, so this should be
reverted to make sure that the next nightly is not parallel-enabled.
This avoids the problems of high thread counts (i.e., contention in the
kernel on the jobserver pipe due to thundering herd of readers) while
stil giving rustc some parallelism to work with.
Fix `-Z print-type-sizes`'s handling of zero-sized fields.
Currently, the type `struct S { x: u32, y: u32, tag: () }` is
incorrectly described like this:
```
print-type-size type: `S`: 8 bytes, alignment: 4 bytes
print-type-size field `.x`: 4 bytes
print-type-size field `.tag`: 0 bytes, offset: 0 bytes, alignment: 1 bytes
print-type-size padding: 4 bytes
print-type-size field `.y`: 4 bytes, alignment: 4 bytes
```
Specifically:
- The `padding` line is wrong. (There is no padding.)
- The `offset` and `alignment` on the `.tag` line shouldn't be printed.
The problem is that multiple fields can end up with the same offset, and
the printing code doesn't handle this correctly.
This commit fixes it by adjusting the field sorting so that zero-sized fields
are dealt with before non-zero-sized fields. With that in place, the
printing code works correctly.
The commit also corrects the "something is very wrong" comment.
The new output looks like this:
```
print-type-size type: `S`: 8 bytes, alignment: 4 bytes
print-type-size field `.tag`: 0 bytes
print-type-size field `.x`: 4 bytes
print-type-size field `.y`: 4 bytes
```
r? @pnkfelix
Add options to --extern flag.
This changes the `--extern` flag so that it can take a series of options that changes its behavior. The general syntax is `[opts ':'] name ['=' path]` where `opts` is a comma separated list of options. Two options are supported, `priv` which replaces `--extern-private` and `noprelude` which avoids adding the crate to the extern prelude.
```text
--extern priv:mylib=/path/to/libmylib.rlib
--extern noprelude:alloc=/path/to/liballoc.rlib
```
`noprelude` is to be used by Cargo's build-std feature in order to use `--extern` to reference standard library crates.
This also includes a second commit which adds the `aux-crate` directive to compiletest. I can split this off into a separate PR if desired, but it helps with defining these kinds of tests. It is based on #54020, and can be used in the future to replace and simplify some of the Makefile tests.
Currently, the type `struct S { x: u32, y: u32, tag: () }` is
incorrectly described like this:
```
print-type-size type: `S`: 8 bytes, alignment: 4 bytes
print-type-size field `.x`: 4 bytes
print-type-size field `.tag`: 0 bytes, offset: 0 bytes, alignment: 1 bytes
print-type-size padding: 4 bytes
print-type-size field `.y`: 4 bytes, alignment: 4 bytes
```
Specifically:
- The `padding` line is wrong. (There is no padding.)
- The `offset` and `alignment` on the `.tag` line shouldn't be printed.
The problem is that multiple fields can end up with the same offset, and
the printing code doesn't handle this correctly.
This commit fixes it by adjusting the field sorting so that zero-sized fields
are dealt with before non-zero-sized fields. With that in place, the
printing code works correctly.
The commit also corrects the "something is very wrong" comment.
The new output looks like this:
```
print-type-size type: `S`: 8 bytes, alignment: 4 bytes
print-type-size field `.tag`: 0 bytes
print-type-size field `.x`: 4 bytes
print-type-size field `.y`: 4 bytes
```
This commit breaks early-lint registration, which will be fixed in the
next commit. This movement will allow essentially all crates in the compiler
tree to declare lints (though not lint passes).
