Closes#16813
r? @nikomatsakis I feel like I should be checking more things in check_rvalues, but not sure what - I don't properly understand expr_use_visitor
Refactor the code in `llvm::back` that invokes LLVM optimization and codegen
passes so that it can be called from worker threads. (Previously, it used
`&Session` extensively, and `Session` is not `Share`.) The new code can handle
multiple compilation units, by compiling each unit to `crate.0.o`, `crate.1.o`,
etc., and linking together all the `crate.N.o` files into a single `crate.o`
using `ld -r`. The later linking steps can then be run unchanged.
The new code preserves the behavior of `--emit`/`-o` when building a single
compilation unit. With multiple compilation units, the `--emit=asm/ir/bc`
options produce multiple files, so combinations like `--emit=ir -o foo.ll` will
not actually produce `foo.ll` (they instead produce several `foo.N.ll` files).
The new code supports `-Z lto` only when using a single compilation unit.
Compiling with multiple compilation units and `-Z lto` will produce an error.
(I can't think of any good reason to do such a thing.) Linking with `-Z lto`
against a library that was built as multiple compilation units will also fail,
because the rlib does not contain a `crate.bytecode.deflate` file. This could
be supported in the future by linking together the `crate.N.bc` files produced
when compiling the library into a single `crate.bc`, or by making the LTO code
support multiple `crate.N.bytecode.deflate` files.
Break up `CrateContext` into `SharedCrateContext` and `LocalCrateContext`. The
local piece corresponds to a single compilation unit, and contains all
LLVM-related components. (LLVM data structures are tied to a specific
`LLVMContext`, and we will need separate `LLVMContext`s to safely run
multithreaded optimization.) The shared piece contains data structures that
need to be shared across all compilation units, such as the `ty::ctxt` and some
tables related to crate metadata.
Different Identifiers and Names can have identical textual representations, but different internal representations, due to the macro hygiene machinery (syntax contexts and gensyms). This provides a way to see these internals by compiling with `--pretty expanded,hygiene`.
This is useful for debugging & hacking on macros (e.g. diagnosing https://github.com/rust-lang/rust/issues/15750/https://github.com/rust-lang/rust/issues/15962 likely would've been faster with this functionality).
E.g.
```rust
#![feature(macro_rules)]
// minimal junk
#![no_std]
macro_rules! foo {
($x: ident) => { y + $x }
}
fn bar() {
foo!(x)
}
```
```rust
#![feature(macro_rules)]
// minimal junk
#![no_std]
fn bar /* 61#0 */() { y /* 60#2 */ + x /* 58#3 */ }
```
`--pretty expanded,hygiene` is helpful with debugging macro issues,
since two identifiers/names can be textually the same, but different
internally (resulting in weird "undefined variable" errors).
This adds support for lint groups to the compiler. Lint groups are a way of
grouping a number of lints together under one name. For example, this also
defines a default lint for naming conventions, named `bad_style`. Writing
`#[allow(bad_style)]` is equivalent to writing
`#[allow(non_camel_case_types, non_snake_case, non_uppercase_statics)]`. These
lint groups can also be defined as a compiler plugin using the new
`Registry::register_lint_group` method.
This also adds two built-in lint groups, `bad_style` and `unused`. The contents
of these groups can be seen by running `rustc -W help`.
Per API meeting
https://github.com/rust-lang/meeting-minutes/blob/master/Meeting-API-review-2014-08-13.md
# Changes to `core::option`
Most of the module is marked as stable or unstable; most of the unstable items are awaiting resolution of conventions issues.
However, a few methods have been deprecated, either due to lack of use or redundancy:
* `take_unwrap`, `get_ref` and `get_mut_ref` (redundant, and we prefer for this functionality to go through an explicit .unwrap)
* `filtered` and `while`
* `mutate` and `mutate_or_set`
* `collect`: this functionality is being moved to a new `FromIterator` impl.
# Changes to `core::result`
Most of the module is marked as stable or unstable; most of the unstable items are awaiting resolution of conventions issues.
* `collect`: this functionality is being moved to a new `FromIterator` impl.
* `fold_` is deprecated due to lack of use
* Several methods found in `core::option` are added here, including `iter`, `as_slice`, and variants.
Due to deprecations, this is a:
[breaking-change]
by-reference upvars.
This partially implements RFC 38. A snapshot will be needed to turn this
on, because stage0 cannot yet parse the keyword.
Part of #12381.
For historical reasons, "Win32" has been used in Rust codebase to mean "Windows OS in general".
This is confusing, especially now, that Rust supports Win64 builds.
[breaking-change]
With this change:
* `--pretty variant=<node-id>` will print the item associated with
`<node-id>` (where `<node-id>` is an integer for some node-id in
the AST, and `variant` means one of {`normal`,`expanded`,...}).
* `--pretty variant=<path-suffix>` will print all of the items that
match the `<path-suffix>` (where `<path-suffix>` is a suffix of a
path, and `variant` again means one of {`normal`,`expanded`,...}).
Example 1: the suffix `typeck::check::check_struct` matches the
item with the path `rustc::middle::typeck::check::check_struct`
when compiling the `rustc` crate.
Example 2: the suffix `and` matches `core::option::Option::and`
and `core::result::Result::and` when compiling the `core` crate.
Both of the `--pretty variant=...` modes will include the full path to
the item in a comment that follows the item.
Note that when multiple paths match, then either:
1. all matching items are printed, in series; this is what happens in
the usual pretty-print variants, or
2. the compiler signals an error; this is what happens in flowgraph
printing.
----
Some drive-by improvements:
Heavily refactored the pretty-printing glue in driver.rs, introducing
a couple local traits to avoid cut-and-pasting very code segments that
differed only in how they accessed the `Session` or the
`ast_map::Map`. (Note the previous code had three similar calls to
`print_crate` which have all been unified in this revision; the
addition of printing individual node-ids exacerbated the situation
beyond tolerance.) We may want to consider promoting some of these
traits, e.g. `SessionCarrier`, for use more generally elsewhere in the
compiler; right now I have to double check how to access the `Session`
depending on what context I am hacking in.
Refactored `PpMode` to make the data directly reflect the fundamental
difference in the categories (in terms of printing source-code with
various annotations, versus printing a control-flow graph).
(also, addressed review feedback.)
Not included are two required patches:
* LLVM: segmented stack support for DragonFly [1]
* jemalloc: simple configure patches
[1]: http://reviews.llvm.org/D4705
When invoking the compiler in parallel, the intermediate output of the object
files and bytecode can stomp over one another if two crates with the same name
are being compiled.
The output file is already being disambiguated with `-C extra-filename`, so this
commit alters the naming of the temporary files to also mix in the extra
filename to ensure that file names don't clash.
except where trait objects are involved.
Part of issue #15349, though I'm leaving it open for trait objects.
Cross borrowing for trait objects remains because it is needed until we
have DST.
This will break code like:
fn foo(x: &int) { ... }
let a = box 3i;
foo(a);
Change this code to:
fn foo(x: &int) { ... }
let a = box 3i;
foo(&*a);
[breaking-change]
The default code model is usually unsuitable for kernels,
so we add an option to specify which model we want.
Testing for this would be fragile and very architecture specific and is better left to LLVM.
Disabling the redzone is required in x86-64's kernel mode to avoid interrupts trashing the stack.
I'm not sure if decl_fn is the right place to tag all functions with noredzone. It might have interactions with external functions when linking with bitcode built without -C no-redzone although I see no reason to do that.
I'm not sure how to write a test inspecting the bitcode output for noredzone attributes on all functions either.
Use one or more of the following `-Z` flag options to tell the
graphviz renderer to include the corresponding dataflow sets (after
the iterative constraint propagation reaches a fixed-point solution):
* `-Z flowgraph-print-loans` : loans computed via middle::borrowck
* `-Z flowgraph-print-moves` : moves computed via middle::borrowck::move_data
* `-Z flowgraph-print-assigns` : assignments, via middle::borrowck::move_data
* `-Z flowgraph-print-all` : all of the available sets are included.
Fix#15016.
Use one or more of the following `-Z` flag options to tell the
graphviz renderer to include the corresponding dataflow sets (after
the iterative constraint propagation reaches a fixed-point solution):
* `-Z flowgraph-print-loans` : loans computed via middle::borrowck
* `-Z flowgraph-print-moves` : moves computed via middle::borrowck::move_data
* `-Z flowgraph-print-assigns` : assignments, via middle::borrowck::move_data
* `-Z flowgraph-print-all` : all of the available sets are included.
Fix#15016.
----
This also adds a module, `syntax::ast_map::blocks`, that captures a
common abstraction shared amongst code blocks and procedure-like
things. As part of this, moved `ast_map.rs` to subdir
`ast_map/mod.rs`, to follow our directory layout conventions.
(incorporated review feedback from huon, acrichto.)
Our AST definition can include macro invocations, which can expand into all kinds of things. Macro invocations are expanded away during expansion time, and the rest of the compiler doesn't have to deal with them. However, we have no way of enforcing this.
This patch adds two protective mechanisms.
First, it adds a (quick) explicit check that ensures there are no macro invocations remaining in the AST after expansion. Second, it updates the visit and fold mechanisms so that by default, they will not traverse macro invocations. It's easy enough to add this, if desired (it's documented in the source, and examples appear, e.g. in the IdentFinder.
Along the way, I also consulted with @sfackler to refactor the macro export mechanism so that it stores macro text spans in a side table, rather than leaving them in the AST.
