Adds the `#[proc_macro]` attribute, which expects bare functions of the kind `fn(TokenStream) -> TokenStream`, which can be invoked like `my_macro!()`.
Corey Farwell [Thu, 2 Mar 2017 19:53:41 +0000 (14:53 -0500)]
Rollup merge of #39832 - phil-opp:x86-interrupt-calling-convention, r=nagisa
Add support for the x86-interrupt calling convention
This calling convention can be used for definining interrupt handlers on 32-bit and 64-bit x86 targets. The compiler then uses `iret` instead of `ret` for returning and ensures that all registers are restored to their
original values.
for exceptions that push an error code (e.g., page faults or general protection faults). The programmer must ensure that the correct version is used for each interrupt.
For more details see the [LLVM PR][1] and the corresponding [proposal][2].
It is also possible to implement interrupt handlers on x86 through [naked functions](https://github.com/rust-lang/rfcs/blob/master/text/1201-naked-fns.md). In fact, almost all existing Rust OS projects for x86 use naked functions for this, including [Redox](https://github.com/redox-os/kernel/blob/b9793deb59c7650f0805dea96adb6b773ad99336/arch/x86_64/src/lib.rs#L109-L147), [IntermezzOS](https://github.com/intermezzOS/kernel/blob/f959cc18c78b1ba153f3ff7039d9ecc07f397628/interrupts/src/lib.rs#L28-L72), and [blog_os](https://github.com/phil-opp/blog_os/blob/844d739379ffdea6a7ede88365ec6e21a725bbf5/src/interrupts/mod.rs#L49-L64). So support for the `x86-interrupt` calling convention isn't absolutely needed.
However, it has a number of benefits to naked functions:
- **No inline assembly needed**: [Inline assembly](https://doc.rust-lang.org/book/inline-assembly.html) is highly unstable and dangerous. It's pretty easy to mess things up. Also, it uses an arcane syntax and requires that the programmer knows x86 assembly.
- **Higher performance**: A naked wrapper function always saves _all_ registers before calling the Rust function. This isn't needed for a compiler supported calling convention, since the compiler knows which registers are clobbered by the interrupt handler. Thus, only these registers need to be saved and restored.
- **Safer interfaces**: We can write a `set_handler` function that takes a `extern "x86-interrupt" fn(&ExceptionStackFrame)` and the compiler ensures that we always use the right function type for all handler functions. This isn't possible with the `#[naked]` attribute.
- **More convenient**: Instead of writing [tons of assembly boilerplate](https://github.com/redox-os/kernel/blob/b9793deb59c7650f0805dea96adb6b773ad99336/arch/x86_64/src/lib.rs#L109-L147) and desperately trying to improve things [through macros](https://github.com/phil-opp/blog_os/blob/844d739379ffdea6a7ede88365ec6e21a725bbf5/src/interrupts/mod.rs#L17-L92), we can just write [code like this](https://github.com/phil-opp/blog_os/blob/e6a61f9507a4c4fef6fb4e3474bc596391bc97d2/src/interrupts/mod.rs#L85-L89).
- **Naked functions are unreliable**: It is allowed to use Rust code inside a naked function, which sometimes works and sometimes not. For example, [calling a function](https://github.com/redox-os/kernel/blob/b9793deb59c7650f0805dea96adb6b773ad99336/arch/x86_64/src/lib.rs#L132) through Rust code seems to work fine without function prologue, but [code declaring a variable](https://is.gd/NQYXqE) silently adds a prologue even though the function is naked (look at the generated assembly, there is a `movl` instruction before the `nop`).
**Edit**: See the [tracking issue](https://github.com/rust-lang/rust/issues/40180) for an updated list of issues.
Unfortunately, the implementation of the `x86-interrupt` calling convention in LLVM has some issues that make it unsuitable for 64-bit kernels at the moment:
- LLVM always tries to backup the `xmm` registers on 64-bit platforms even if the target doesn't support SSE. This leads to invalid opcode exceptions whenever an interrupt handler is invoked. I submitted a fix to LLVM in [D29959](https://reviews.llvm.org/D29959). The fix is really small (<10 lines), so maybe we could backport it to [Rust's LLVM fork](https://github.com/rust-lang/llvm)?. **Edit**: The fix was merged to LLVM trunk in [rL295347](https://reviews.llvm.org/rL295347). Backported in https://github.com/rust-lang/llvm/pull/63.
- On targets with SSE support, LLVM uses the `movaps` instruction for saving the `xmm` registers, which requires an alignment of 16. For handlers with error codes, however, the stack alignment is only 8, so a alignment exception occurs. This issue is tracked in [bug 26413](https://bugs.llvm.org/show_bug.cgi?id=26413). ~~Unfortunately, I don't know enough about LLVM to fix this.~~ **Edit**: Fix submitted in [D30049](https://reviews.llvm.org/D30049).
This PR adds experimental support for this calling convention under the `abi_x86_interrupt` feature gate. The implementation is very similar to #38465 and was surprisingly simple :).
There is no accepted RFC for this change. In fact, the [RFC for interrupt calling convention](https://github.com/rust-lang/rfcs/pull/1275) from 2015 was closed in favor of naked functions. However, the reactions to the recent [PR](https://github.com/rust-lang/rust/pull/38465) for a MSP430 interrupt calling convention were [in favor of experimental interrupt ABIs](https://github.com/rust-lang/rust/pull/38465#issuecomment-270015470).
- [x] Add compile-fail tests for the feature gate.
- [x] Create tracking issue for the `abi_x86_interrupt` feature (and link it in code). **Edit**: Tracking issue: #40180
- [x] Backport [rL295347](https://reviews.llvm.org/rL295347) to Rust's LLVM fork. **Edit**: Done in https://github.com/rust-lang/llvm/pull/63
@tari @steveklabnik @jackpot51 @ticki @hawkw @thepowersgang, you might be interested in this.
This calling convention can be used for definining interrupt handlers on
32-bit and 64-bit x86 targets. The compiler then uses `iret` instead of
`ret` for returning and ensures that all registers are restored to their
original values.
for exceptions that push an error code (e.g., page faults or general
protection faults). The programmer must ensure that the correct version
is used for each interrupt.
For more details see the [LLVM PR][1] and the corresponding [proposal][2].
Guillaume Gomez [Thu, 2 Mar 2017 10:29:41 +0000 (11:29 +0100)]
Rollup merge of #40175 - d-e-s-o:fix-inconsistency-in-guessing-game-readme, r=steveklabnik
doc: fix inconsistency in error output in guessing-game.md
The line '.expect("failed to read line");' is partly started with a
lower case 'f' and partly with an uppercase one, adding additional
spurious changes to otherwise clean diffs if each sample is
copy-and-pasted over the previous.
This change starts the string with an uppercase everywhere which is in
line with the style of the other strings.
deso [Wed, 1 Mar 2017 13:44:50 +0000 (05:44 -0800)]
doc: fix inconsistency in error output in guessing-game.md
The line '.expect("failed to read line");' is partly started with a
lower case 'f' and partly with an uppercase one, adding additional
spurious changes to otherwise clean diffs if each sample is
copy-and-pasted over the previous.
This change starts the string with an uppercase everywhere which is in
line with the style of the other strings.
bors [Wed, 1 Mar 2017 10:03:44 +0000 (10:03 +0000)]
Auto merge of #34198 - eddyb:you're-a-bad-transmute-and-you-should-feel-bad, r=nikomatsakis
Make transmuting from fn item types to pointer-sized types a hard error.
Closes #19925 by removing the future compatibility lint and the associated workarounds.
This is a `[breaking-change]` if you `transmute` from a function item without casting first.
For more information on how to fix your code, see https://github.com/rust-lang/rust/issues/19925.
bors [Wed, 1 Mar 2017 05:58:09 +0000 (05:58 +0000)]
Auto merge of #39419 - jseyfried:simplify_tokentree, r=nrc
Simplify `TokenTree` and fix `macro_rules!` bugs
This PR
- fixes #39390, fixes #39403, and fixes #39404 (each is a [breaking-change], see issues for examples),
- fixes #39889,
- simplifies and optimizes macro invocation parsing,
- cleans up `ext::tt::transcribe`,
- removes `tokenstream::TokenTree::Sequence` and `Token::MatchNt`,
- instead, adds a new type `ext::tt::quoted::TokenTree` for use by `macro_rules!` (`ext::tt`)
- removes `parser.quote_depth` and `parser.parsing_token_tree`, and
- removes `quote_matcher!`.
- Instead, use `quote_tokens!` and `ext::tt::quoted::parse` the result with `expect_matchers=true`.
- I found no outside uses of `quote_matcher!` when searching Rust code on Github.
Corey Farwell [Wed, 1 Mar 2017 03:55:26 +0000 (22:55 -0500)]
Rollup merge of #39419 - jseyfried:simplify_tokentree, r=nrc
Simplify `TokenTree` and fix `macro_rules!` bugs
This PR
- fixes #39390, fixes #39403, and fixes #39404 (each is a [breaking-change], see issues for examples),
- fixes #39889,
- simplifies and optimizes macro invocation parsing,
- cleans up `ext::tt::transcribe`,
- removes `tokenstream::TokenTree::Sequence` and `Token::MatchNt`,
- instead, adds a new type `ext::tt::quoted::TokenTree` for use by `macro_rules!` (`ext::tt`)
- removes `parser.quote_depth` and `parser.parsing_token_tree`, and
- removes `quote_matcher!`.
- Instead, use `quote_tokens!` and `ext::tt::quoted::parse` the result with `expect_matchers=true`.
- I found no outside uses of `quote_matcher!` when searching Rust code on Github.
Steve Klabnik [Tue, 28 Feb 2017 23:38:43 +0000 (15:38 -0800)]
Rollup merge of #40153 - steveklabnik:alphabetize-unstable-book, r=frewsxcv
sort unstable book alphabetically
I made these the same order as they were in the compiler, but for no good reason. Much easier to find out what you need when they're sorted alphabetically
Steve Klabnik [Tue, 28 Feb 2017 19:06:05 +0000 (14:06 -0500)]
sort unstable book alphabetically
I made these the same order as they were in the compiler, but for no good reason. Much easier to find out what you need when they're sorted alphabetically
Corey Farwell [Tue, 28 Feb 2017 13:33:10 +0000 (08:33 -0500)]
Rollup merge of #40131 - MajorBreakfast:patch-3, r=steveklabnik
Make lifetime elision docs clearer
Previously it said
"It's forbidden to allow reasoning about types based on the item signature alone."
I think that sentence is wrong. Rust **uses** the item signatures to perform type inference within the body. I think what's meant is the other way around: It does not infer types for item signatures.
Corey Farwell [Tue, 28 Feb 2017 13:33:07 +0000 (08:33 -0500)]
Rollup merge of #40122 - robinst:process-add-example-for-writing-to-stdin, r=alexcrichton
Example for how to provide stdin using std::process::Command
Spawning a child process and writing to its stdin is a bit tricky due to
`as_mut` and having to use a limited borrow. An example for this might
help newer users.
Corey Farwell [Tue, 28 Feb 2017 13:33:04 +0000 (08:33 -0500)]
Rollup merge of #40056 - keeperofdakeys:contributing, r=alexcrichton
Replace ./configure with config.toml in README.md and CONTRIBUTING.md
Replace ./configure with config.toml in README.md and CONTRIBUTING.md, so that new users aren't confused about which build system to use, and how to configure the build process.
Corey Farwell [Tue, 28 Feb 2017 13:33:00 +0000 (08:33 -0500)]
Rollup merge of #39977 - frewsxcv:error-reporting-cleanup, r=eddyb
librustc error_reporting.rs cleanup.
Read some code in librustc, mainly in error_reporting.rs, and cleaned up some things along the way. I recommend looking at each commit individually or looking at the [whitespace insensitive diff](https://github.com/rust-lang/rust/pull/39977/files?w=1).
bors [Tue, 28 Feb 2017 10:00:31 +0000 (10:00 +0000)]
Auto merge of #40135 - alexcrichton:split-android, r=aturon
travis: Split Android into dist/test images
PRs can't land againt beta right now because the android bot is filling up on
disk space. I don't really know what's going on but the android bot is the
longest one to run anyway so it'll benefit from being split up regardless.
bors [Tue, 28 Feb 2017 07:59:25 +0000 (07:59 +0000)]
Auto merge of #40008 - eddyb:lazy-12, r=nikomatsakis
[12/12] On-demand type-checking, const-evaluation, MIR building & const-qualification.
_This is the last of a series ([prev](https://github.com/rust-lang/rust/pull/38813)) of patches designed to rework rustc into an out-of-order on-demand pipeline model for both better feature support (e.g. [MIR-based](https://github.com/solson/miri) early constant evaluation) and incremental execution of compiler passes (e.g. type-checking), with beneficial consequences to IDE support as well.
If any motivation is unclear, please ask for additional PR description clarifications or code comments._
<hr>
As this contains all of the changes that didn't fit neatly into other PRs, I'll be elaborating a bit:
### User-facing changes
* when determining whether an `impl Trait` type implements an auto-trait (e.g. `Send` or `Sync`), the function the `impl Trait` came from has to be inferred and type-checking, disallowing cycles
* this results from not having an obvious place to put the "deferred obligation" in on-demand atm
* while we could model side-effects like that and "post-processing passes" better, it's still more limiting than being able to know the result in the original function (e.g. specialization) *and* there are serious problems around region-checking (if a `Send` impl required `'static`, it wasn't enforced)
* early const-eval requires type-checking and const-qualification to be performed first, which means:
* you get the intended errors before (if any) constant evaluation error that is simply fallout
* associated consts should always work now, and `const fn` type parameters are properly tracked
* don't get too excited, array lengths still can't depend on type parameters
* #38864 works as intended now, with `Self` being allowed in `impl` bounds
* #32205 is largely improved, with associated types being limited to "exact match" `impl`s (as opposed to traversing the specialization graph to resolve unspecified type parameters to their defaults in another `impl` or in the `trait`) *while* checking for overlaps building the specialization graph for that trait - once all the trait impls' have been checked for coherence (including ahead-of-time/on-demand), it's uniform
* [crater report](https://gist.github.com/eddyb/bbb869072468c7e08d6d808e75938051) looks clean (aside from `clippy` which broke due to `rustc` internal changes)
### Compiler-internal changes
* `ty::Generics`
* no longer contains the actual type parameter defaults, instead they're associated with the type parameter's `DefId`, like associated types in a trait definition
* this allows computing `ty::Generics` as a leaf (reading only its own HIR)
* holds a mapping from `DefIndex` of type parameters to their indices
* `ty::AdtDef`
* only tracks `#[repr(simd)]` in its `ReprOptions` `repr` field
* doesn't contain `enum` discriminant values, but instead each variant either refers to either an explicit value for its discriminant, or the distance from the last explicit discriminant, if any
* the `.discriminants(tcx)` method produces an iterator of `ConstInt` values, looking up explicit discriminants in a separate map, if necessary
* this allows computing `ty::AdtDef` as a leaf (reading only its own HIR)
* Small note: the two above (`Generics`, `AdtDef`), `TraitDef` and `AssociatedItem` should probably end up as part of the HIR, eventually, as they're trivially constructed from it
* `ty::FnSig`
* now also holds ABI and unsafety, alongside argument types, return type and C variadicity
* `&ty::BareFnTy` and `ty::ClosureTy` have been replaced with `PolyFnSig = Binder<FnSig>`
* `BareFnTy` was interned and `ClosureTy` was treated as non-trivial to `Clone` because they had a `PolyFnSig` and so used to contain a `Vec<Ty>` (now `&[Ty]`)
* `ty::maps`
* all the `DepTrackingMap`s have been grouped in a structure available at `tcx.maps`
* when creating the `tcx`, a set of `Providers` (one `fn` pointer per map) is required for the local crate, and one for all other crates (i.e. metadata loading), `librustc_driver` plugging the various crates (e.g. `librustc_metadata`, `librustc_typeck`, `librustc_mir`) into it
* when a map is queried and the value is missing, the appropriate `fn` pointer from the `Providers` of that crate is called with the `TyCtxt` and the key being queried, to produce the value on-demand
* `rustc_const_eval`
* demands both `typeck_tables` and `mir_const_qualif` (in preparation for miri)
* tracks `Substs` in `ConstVal::Function` for `const fn` calls
* returns `TypeckError` if type-checking has failed (or cases that can only be reached if it had)
* this error kind is never reported, resulting in less noisy/redundant diagnostics
* fixes #39548 (testcase by @larsluthman, taken from #39812, which this supersedes)
* on-demand has so far been hooked up to:
* `rustc_metadata::cstore_impl`: `ty`, `generics`, `predicates`, `super_predicates`, `trait_def`, `adt_def`, `variances`, `associated_item_def_ids`, `associated_item`, `impl_trait_ref`, `custom_coerce_unsized_kind`, `mir`, `mir_const_qualif`, `typeck_tables`, `closure_kind`, `closure_type`
* `rustc_typeck::collect`: `ty`, `generics`, `predicates`, `super_predicates`, `type_param_predicates`, `trait_def`, `adt_def`, `impl_trait_ref`
* `rustc_typeck::coherence`: `coherent_trait`, `coherent_inherent_impls`
* `rustc_typeck::check`: `typeck_tables`, `closure_type`, `closure_kind`
* `rustc_mir::mir_map`: `mir`
* `rustc_mir::transform::qualify_consts`: `mir_const_qualif`
Alex Crichton [Mon, 27 Feb 2017 22:53:12 +0000 (14:53 -0800)]
travis: Split Android into dist/test images
PRs can't land againt beta right now because the android bot is filling up on
disk space. I don't really know what's going on but the android bot is the
longest one to run anyway so it'll benefit from being split up regardless.
bors [Tue, 28 Feb 2017 02:26:09 +0000 (02:26 +0000)]
Auto merge of #40095 - alexcrichton:sccache-mingw, r=brson
appveyor: Use sccache on pc-windows-gnu for caching
Now that mozilla/sccache#43 is fixed the caching works for MinGW on Windows. We
still can't use it for MSVC just yet, but I'll try to revive that branch at some
point.
Alex Crichton [Sat, 25 Feb 2017 08:53:12 +0000 (00:53 -0800)]
appveyor: Use sccache on pc-windows-gnu for caching
Now that mozilla/sccache#43 is fixed the caching works for MinGW on Windows. We
still can't use it for MSVC just yet, but I'll try to revive that branch at some
point.
bors [Mon, 27 Feb 2017 17:21:37 +0000 (17:21 +0000)]
Auto merge of #38165 - Yamakaky:better-backtrace, r=petrochenkov
Improve backtrace formating while panicking.
Fixes #37783.
Done:
- Fix alignment of file paths for better readability
- `RUST_BACKTRACE=full` prints all the informations (current behaviour)
- `RUST_BACKTRACE=(short|yes)` is the default and does:
- Skip irrelevant frames at the beginning and the end
- Remove function address
- Remove the current directory from the absolute paths
- Remove `::hfabe6541873` at the end of the symbols
- `RUST_BACKTRACE=(0|no)` disables the backtrace.
- `RUST_BACKTRACE=<everything else>` is equivalent to `short` for
backward compatibility.
- doc
- More uniform printing across platforms.
Removed, TODO in a new PR:
- Remove path prefix for libraries and libstd
Example of short backtrace:
```rust
fn fail() {
panic!();
}
fn main() {
let closure = || fail();
closure();
}
```
Short:
```
thread 'main' panicked at 'explicit panic', t.rs:2
Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
stack backtrace:
0: t::fail
at ./t.rs:2
1: t::main::{{closure}}
at ./t.rs:6
2: t::main
at ./t.rs:7
```
Full:
```
thread 'main' panicked at 'This function never returns!', t.rs:2
stack backtrace:
0: 0x558ddf666478 - std::sys::imp::backtrace::tracing::imp::unwind_backtrace::hec84c9dd8389cc5d
at /home/yamakaky/dev/rust/rust/src/libstd/sys/unix/backtrace/tracing/gcc_s.rs:49
1: 0x558ddf65d90e - std::sys_common::backtrace::_print::hfa25f8b31f4b4353
at /home/yamakaky/dev/rust/rust/src/libstd/sys_common/backtrace.rs:71
2: 0x558ddf65cb5e - std::sys_common::backtrace::print::h9b711e11ac3ba805
at /home/yamakaky/dev/rust/rust/src/libstd/sys_common/backtrace.rs:60
3: 0x558ddf66796e - std::panicking::default_hook::{{closure}}::h736d216e74748044
at /home/yamakaky/dev/rust/rust/src/libstd/panicking.rs:355
4: 0x558ddf66743c - std::panicking::default_hook::h16baff397e46ea10
at /home/yamakaky/dev/rust/rust/src/libstd/panicking.rs:371
5: 0x558ddf6682bc - std::panicking::rust_panic_with_hook::h6d5a9bb4eca42c80
at /home/yamakaky/dev/rust/rust/src/libstd/panicking.rs:559
6: 0x558ddf64ea93 - std::panicking::begin_panic::h17dc549df2f10b99
at /home/yamakaky/dev/rust/rust/src/libstd/panicking.rs:521
7: 0x558ddf64ec42 - t::diverges::he6bc43fc925905f5
at /tmp/p/t.rs:2
8: 0x558ddf64ec5a - t::main::h0ffc20356b8a69c0
at /tmp/p/t.rs:6
9: 0x558ddf6687f5 - core::ops::FnOnce::call_once::hce41f19c0db56f93
10: 0x558ddf667cde - std::panicking::try::do_call::hd4c8c97efb4291df
at /home/yamakaky/dev/rust/rust/src/libstd/panicking.rs:464
11: 0x558ddf698d77 - __rust_try
12: 0x558ddf698c57 - __rust_maybe_catch_panic
at /home/yamakaky/dev/rust/rust/src/libpanic_unwind/lib.rs:98
13: 0x558ddf667adb - std::panicking::try::h2c56ed2a59ec1d12
at /home/yamakaky/dev/rust/rust/src/libstd/panicking.rs:440
14: 0x558ddf66cc9a - std::panic::catch_unwind::h390834e0251cc9af
at /home/yamakaky/dev/rust/rust/src/libstd/panic.rs:361
15: 0x558ddf6809ee - std::rt::lang_start::hb73087428e233982
at /home/yamakaky/dev/rust/rust/src/libstd/rt.rs:57
16: 0x558ddf64ec92 - main
17: 0x7fecb869e290 - __libc_start_main
18: 0x558ddf64e8b9 - _start
19: 0x0 - <unknown>
```
Robin Stocker [Mon, 27 Feb 2017 06:01:47 +0000 (17:01 +1100)]
Example for how to provide stdin using std::process::Command
Spawning a child process and writing to its stdin is a bit tricky due to
`as_mut` and having to use a limited borrow. An example for this might
help newer users.