Enhance report-time option
## Short overview
This PR is a follow-up to a previously closed#64714 PR.
## Changes introduced by this PR
* `libtest` now retrieves the type of the test within `TestDesc` (available types are: `UnitTest`, `IntegrationTest`, `DocTest`, `Unknown`).
* `--report-time` subcommand of the `libtest` now supports colored output (disabled by default).
* Colorized output depends on the threshold values. Default values (proposed by @wesleywiser):
- For unit-tests: 50ms warn/100ms critical,
- For integration-tests: 500ms warn/1000ms critical,
- For doctests: same as for integration tests,
- For unknown tests: `TEST_WARN_TIMEOUT_S` warn/ `TEST_WARN_TIMEOUT_S * 2` critical (it will only applied single-threaded mode, because otherwise test will be interrupted after reaching `TEST_WARN_TIMEOUT_S`).
- These values can be overrided by setting environment variables (since those thresholds are somewhat constant for every project, it's more flexible to use environment variables than command line arguments).
* New optional flag `--ensure-test-time` for `libtest`. With this flag applied, exectuion time limit excesss will cause test failure.
## What have not been done
There was a comment that it would be nice to have an entry in the Cargo book about it.
However, changes introduced by this PR (and #64663 in which `report-time` flag was added) aren't related directly to `cargo`, it's more about `libtest` itself.
I'm considering that [The Unstable Book](https://doc.rust-lang.org/unstable-book/) is more appropriate place, but not sure if I'm right (and if so, how exactly it should be described).
As one possible option, this PR may be merged without denoting it in the documentation, and in the next PR adding support of this feature to the `cargo` itself, I'll add a note in the Cargo book.
## Scope of this PR
Logical scope of this PR is `libtest` only. However, to get test types, I had to modify also `libsyntax_ext` and `librustdoc` for them to provide information about test type.
## Rationale
Rationale for colored output was submitted in #64714
Providing the information about kind of test was also proposed in #64714, and as an additional benefit this information may be useful for the tools using `libtest` (e.g. `cargo`).
Adding flag to treat time limits excess seems logical to me, so projects that do care about test execution time won't have to invent a wheel.
## Backward compatibility
All the changes are completely backward compatible.
## Demo

r? @wesleywiser
- The attribute is behind a feature gate.
- Error if both #[naked] and #[track_caller] are applied to the same function.
- Error if #[track_caller] is applied to a non-function item.
- Error if ABI is not "rust"
- Error if #[track_caller] is applied to a trait function.
Error codes and descriptions are pending.
- 771c5d10cf944bf7d221f5d6cb7abd2a06c400e4 Add macros in extern blocks and new proc-macro support.
- 8caabd62ef5fbe99e6be6aa9e76f55bbb8433d95 Update for "modern" `meta` matcher.
- 1b44947d36ccf7eba2b3bd245769eff68abf6d4d Update await desugaring after rust-lang/rust#64292
Stabilize `param_attrs` in Rust 1.39.0
# Stabilization proposal
I propose that we stabilize `#![feature(param_attrs)]`.
Tracking issue: #60406
Version: 1.39 (2019-09-26 => beta, 2019-11-07 => stable).
## What is stabilized
It is now possible to add outer attributes like `#[cfg(..)]` on formal parameters of functions, closures, and function pointer types. For example:
```rust
fn len(
#[cfg(windows)] slice: &[u16],
#[cfg(not(windows))] slice: &[u8],
) -> usize {
slice.len()
}
```
## What isn't stabilized
* Documentation comments like `/// Doc` on parameters.
* Code expansion of a user-defined `#[proc_macro_attribute]` macro used on parameters.
* Built-in attributes other than `cfg`, `cfg_attr`, `allow`, `warn`, `deny`, and `forbid`. Currently, only the lints `unused_variables` and `unused_mut` have effect and may be controlled on parameters.
## Motivation
The chief motivations for stabilizing `param_attrs` include:
* Finer conditional compilation with `#[cfg(..)]` and linting control of variables.
* Richer macro DSLs created by users.
* External tools and compiler internals can take advantage of the additional information that the parameters provide.
For more examples, see the [RFC][rfc motivation].
## Reference guide
In the grammar of function and function pointer, the grammar of variadic tails (`...`) and parameters are changed respectively from:
```rust
FnParam = { pat:Pat ":" }? ty:Type;
VaradicTail = "...";
```
into:
```rust
FnParam = OuterAttr* { pat:Pat ":" }? ty:Type;
VaradicTail = OuterAttr* "...";
```
The grammar of a closure parameter is changed from:
```rust
ClosureParam = pat:Pat { ":" ty:Type }?;
```
into:
```rust
ClosureParam = OuterAttr* pat:Pat { ":" ty:Type }?;
```
More generally, where there's a list of formal (value) parameters separated or terminated by `,` and delimited by `(` and `)`. Each parameter in that list may optionally be prefixed by `OuterAttr+`.
Note that in all cases, `OuterAttr*` applies to the whole parameter and not just the pattern. This distinction matters in pretty printing and in turn for macros.
## History
* On 2018-10-15, @Robbepop proposes [RFC 2565][rfc], "Attributes in formal function parameter position".
* On 2019-04-30, [RFC 2565][rfc] is merged and the tracking issue is made.
* On 2019-06-12, a partial implementation was completed. The implementation was done in [#60669][60669] by @c410-f3r and the PR was reviewed by @petrochenkov and @Centril.
* On 2019-07-29, [#61238][61238] was fixed in [#61856][61856]. The issue fixed was that lint attributes on function args had no effect. The PR was written by @c410-f3r and reviewed by @matthewjasper, @petrochenkov, and @oli-obk.
* On 2019-08-02, a bug [#63210][63210] was filed wherein the attributes on formal parameters would not be passed to macros. The issue was about forgetting to call the relevant method in `fn print_arg` in the pretty printer. In [#63212][63212], written by @Centril on 2019-08-02 and reviewed by @davidtwco, the issue aforementioned was fixed.
* This PR stabilizes `param_attrs`.
## Tests
* [On Rust 2018, attributes aren't permitted on function parameters without a pattern in trait definitions.](https://github.com/rust-lang/rust/blob/master/src/test/ui/rfc-2565-param-attrs/param-attrs-2018.rs)
* [All attributes that should be allowed. This includes `cfg`, `cfg_attr`, and lints check attributes.](https://github.com/rust-lang/rust/blob/master/src/test/ui/rfc-2565-param-attrs/param-attrs-allowed.rs)
* [Built-in attributes, which should be forbidden, e.g., `#[test]`, are.](https://github.com/rust-lang/rust/blob/master/src/test/ui/rfc-2565-param-attrs/param-attrs-builtin-attrs.rs)
* [`cfg` and `cfg_attr` are properly evaluated.](https://github.com/rust-lang/rust/blob/master/src/test/ui/rfc-2565-param-attrs/param-attrs-cfg.rs)
* [`unused_mut`](46f405ec4d/src/test/ui/rfc-2565-param-attrs/param-attrs-cfg.rs) and [`unused_variables`](https://github.com/rust-lang/rust/blob/master/src/test/ui/lint/lint-unused-variables.rs) are correctly applied to parameter patterns.
* [Pretty printing takes formal parameter attributes into account.](https://github.com/rust-lang/rust/blob/master/src/test/ui/rfc-2565-param-attrs/param-attrs-pretty.rs)
## Possible future work
* Custom attributes inside function parameters aren't currently supported but it is something being worked on internally.
* Since documentation comments are syntactic sugar for `#[doc(...)]`, it is possible to allow literal `/// Foo` comments on function parameters.
[rfc motivation]: https://github.com/rust-lang/rfcs/blob/master/text/2565-formal-function-parameter-attributes.md#motivation
[rfc]: https://github.com/rust-lang/rfcs/pull/2565
[60669]: https://github.com/rust-lang/rust/pull/60669
[61856]: https://github.com/rust-lang/rust/pull/61856
[63210]: https://github.com/rust-lang/rust/issues/63210
[61238]: https://github.com/rust-lang/rust/issues/61238
[63212]: https://github.com/rust-lang/rust/pull/63212
This report is a collaborative work with @Centril.
Allow cross-compiling doctests
This PR allows doctest to receive a --runtool argument, as well as possibly many --runtool-arg arguments, which are then used to run cross compiled doctests.
Also, functionality has been added to rustdoc to allow it to skip testing doctests on a per-target basis, in the same way that compiletest does it. For example, tagging the doctest with "ignore-sgx" disables testing on any targets that contain "sgx". A plain "ignore" still skips testing on all targets.
See [here](https://github.com/rust-lang/cargo/pull/6892) for the companion PR in the cargo project that extends functionality in Cargo so that it passes the appropriate parameters to rustdoc when cross compiling and testing doctests.
Part of [#6460](https://github.com/rust-lang/cargo/issues/6460)
Update xLTO compatibility table in rustc book.
This is a combination known to work reliable when building Firefox on all the major platforms.
r? @alexcrichton
use the code generation parameter -Clinker (same parameter as rustc)
to control what linker to use for building the rustdoc test executables.
closes: #63816
rustc: implement argsfiles for command line
Many tools, such as gcc and gnu-ld, support "args files" - that is, being able to specify @file on the command line. This causes `file` to be opened and parsed for command line options. They're separated with whitespace; whitespace can be quoted with double or single quotes, and everything can be \\-escaped. Args files may recursively include other args files via `@file2`.
See https://sourceware.org/binutils/docs/ld/Options.html#Options for the documentation of gnu-ld's @file parameters.
This is useful for very large command lines, or when command lines are being generated into files by other tooling.
This makes `rustc` support `@path` arguments on the command line. The `path` is opened and the file is interpreted
as new command line options which are logically inserted at that point in the command-line. The options in the file
are one per line. The file is UTF-8 encoded, and may have either Unix or Windows line endings.
It does not support recursive use of `@path`.
This is useful for very large command lines, or when command-lines are being generated into files by other tooling.
rustc: Stabilize options for pipelined compilation
This commit stabilizes options in the compiler necessary for Cargo to
enable "pipelined compilation" by default. The concept of pipelined
compilation, how it's implemented, and what it means for rustc are
documented in #60988. This PR is coupled with a PR against Cargo
(rust-lang/cargo#7143) which updates Cargo's support for pipelined
compliation to rustc, and also enables support by default in Cargo.
(note that the Cargo PR cannot land until this one against rustc lands).
The technical changes performed here were to stabilize the functionality
proposed in #60419 and #60987, the underlying pieces to enable pipelined
compilation support in Cargo. The issues have had some discussion during
stabilization, but the newly stabilized surface area here is:
* A new `--json` flag was added to the compiler.
* The `--json` flag can be passed multiple times.
* The value of the `--json` flag is a comma-separated list of
directives.
* The `--json` flag cannot be combined with `--color`
* The `--json` flag must be combined with `--error-format=json`
* The acceptable list of directives to `--json` are:
* `diagnostic-short` - the `rendered` field of diagnostics will have a
"short" rendering matching `--error-format=short`
* `diagnostic-rendered-ansi` - the `rendered` field of diagnostics
will be colorized with ansi color codes embedded in the string field
* `artifacts` - JSON blobs will be emitted for artifacts being emitted
by the compiler
The unstable `-Z emit-artifact-notifications` and `--json-rendered`
flags have also been removed during this commit as well.
Closes#60419Closes#60987Closes#60988
cleanup: Remove some language features related to built-in macros
They are now library features.
Cleanup after https://github.com/rust-lang/rust/pull/62086.
The unstable book files are moved because tidy complained.
This commit stabilizes options in the compiler necessary for Cargo to
enable "pipelined compilation" by default. The concept of pipelined
compilation, how it's implemented, and what it means for rustc are
documented in #60988. This PR is coupled with a PR against Cargo
(rust-lang/cargo#7143) which updates Cargo's support for pipelined
compliation to rustc, and also enables support by default in Cargo.
(note that the Cargo PR cannot land until this one against rustc lands).
The technical changes performed here were to stabilize the functionality
proposed in #60419 and #60987, the underlying pieces to enable pipelined
compilation support in Cargo. The issues have had some discussion during
stabilization, but the newly stabilized surface area here is:
* A new `--json` flag was added to the compiler.
* The `--json` flag can be passed multiple times.
* The value of the `--json` flag is a comma-separated list of
directives.
* The `--json` flag cannot be combined with `--color`
* The `--json` flag must be combined with `--error-format=json`
* The acceptable list of directives to `--json` are:
* `diagnostic-short` - the `rendered` field of diagnostics will have a
"short" rendering matching `--error-format=short`
* `diagnostic-rendered-ansi` - the `rendered` field of diagnostics
will be colorized with ansi color codes embedded in the string field
* `artifacts` - JSON blobs will be emitted for artifacts being emitted
by the compiler
The unstable `-Z emit-artifact-notifications` and `--json-rendered`
flags have also been removed during this commit as well.
Closes#60419Closes#60987Closes#60988