Commit Graph

472 Commits

Author SHA1 Message Date
Wesley Wiser
903c0399e7 Enable the SimplifyArmIdentity MIR optimization at mir-opt-level=1 2020-09-03 21:16:30 -04:00
Tomasz Miąsko
01510612ee NRVO: Allow occurrences of the return place in var debug info
The non-use occurrence of the return place in var debug info does not
currently inhibit NRVO optimization, but it will fail assertion in
`visit_place` when optimization is performed.

Relax assertion check to allow the return place in var debug info.

This case might be impossible to hit in optimization pipelines as of
now, but can be encountered in customized mir-opt-level=2 pipeline with
copy propagation disabled. For example in:

```
pub fn b(s: String) -> String {
    a(s)
}

#[inline]
pub fn a(s: String) -> String {
    let x = s;
    let y = x;
    y
}
```
2020-09-04 02:33:37 +02:00
Tomasz Miąsko
326b772609 inliner: Check for no_sanitize attribute compatibility 2020-09-04 20:01:15 +02:00
Tomasz Miąsko
cbc396fdfb inliner: Check for target features compatibility 2020-09-04 19:36:45 +02:00
bors
af3c6e733a Auto merge of #73996 - da-x:short-unique-paths, r=petrochenkov
diagnostics: shorten paths of unique symbols

This is a step towards implementing a fix for #50310, and continuation of the discussion in [Pre-RFC: Nicer Types In Diagnostics - compiler - Rust Internals](https://internals.rust-lang.org/t/pre-rfc-nicer-types-in-diagnostics/11139). Impressed upon me from previous discussion in #21934 that an RFC for this is not needed, and I should just come up with code.

The recent improvements to `use` suggestions that I've contributed have given rise to this implementation. Contrary to previous suggestions, it's rather simple logic, and I believe it only reduces the amount of cognitive load that a developer would need when reading type errors.

-----

If a symbol name can only be imported from one place, and as long as it was not glob-imported anywhere in the current crate, we can trim its printed path to the last component.

This has wide implications on error messages with types, for example, shortening `std::vec::Vec` to just `Vec`, as long as there is no other `Vec` importable from anywhere.
2020-09-03 23:27:45 +00:00
Tomasz Miąsko
9daf8fd5b1 inliner: Emit storage markers for introduced arg temporaries
When introducing argument temporaries during inlining, emit storage
marker statements just before the assignment and in the beginning of
the return block.

This ensures that such temporaries will not be considered live across
yield points after inlining inside a generator.
2020-09-03 17:01:27 +02:00
Rich Kadel
51d692cf77 Tools, tests, and experimenting with MIR-derived coverage counters
Adds a new mir_dump output file in HTML/CSS to visualize code regions
and the MIR features that they came from (including overlapping spans).
See example below:

Includes a basic, MIR-block-based implementation of coverage injection,
available via `-Zexperimental-coverage`. This implementation has known
flaws and omissions, but is simple enough to validate the new tools and
tests.

The existing `-Zinstrument-coverage` option currently enables
function-level coverage only, which at least appears to generate
accurate coverage reports at that level.

Experimental coverage is not accurate at this time. When branch coverage
works as intended, the `-Zexperimental-coverage` option should be
removed.

This PR replaces the bulk of PR #75828, with the remaining parts of
that PR distributed among other separate and indentpent PRs.

This PR depends on three of those other PRs: #76000, #76002, and

Rust compiler MCP rust-lang/compiler-team#278

Relevant issue: #34701 - Implement support for LLVMs code coverage
instrumentation

![Screen-Recording-2020-08-21-at-2](https://user-images.githubusercontent.com/3827298/90972923-ff417880-e4d1-11ea-92bb-8713c6198f6d.gif)
2020-09-03 00:20:29 -07:00
Dan Aloni
07e7823c01 pretty: trim paths of unique symbols
If a symbol name can only be imported from one place for a type, and
as long as it was not glob-imported anywhere in the current crate, we
can trim its printed path and print only the name.

This has wide implications on error messages with types, for example,
shortening `std::vec::Vec` to just `Vec`, as long as there is no other
`Vec` importable anywhere.

This adds a new '-Z trim-diagnostic-paths=false' option to control this
feature.

On the good path, with no diagnosis printed, we should try to avoid
issuing this query, so we need to prevent trimmed_def_paths query on
several cases.

This change also relies on a previous commit that differentiates
between `Debug` and `Display` on various rustc types, where the latter
is trimmed and presented to the user and the former is not.
2020-09-02 22:26:37 +03:00
Mark Rousskov
990a39596c Prevent ICE on uninhabited MIR interpretation 2020-09-02 08:37:48 -04:00
Tomasz Miąsko
6c51ec96bb inliner: Avoid query cycles when optimizing generators
The HIR Id trick is insufficient to prevent query cycles when optimizing
generators, since merely requesting a layout of a generator also
computes its `optimized_mir`.

Make no attempts to inline functions into generators within the same
crate to avoid query cycles.
2020-09-02 00:00:00 +00:00
Rich Kadel
6b5869a0ae Add new -Z dump-mir-spanview option
Similar to `-Z dump-mir-graphviz`, this adds the option to write
HTML+CSS files that allow users to analyze the spans associated with MIR
elements (by individual statement, just terminator, or overall basic
block).

This PR was split out from PR #76004, and exposes an API for spanview
HTML+CSS files that is also used to analyze code regions chosen for
coverage instrumentation (in a follow-on PR).

Rust compiler MCP rust-lang/compiler-team#278

Relevant issue: #34701 - Implement support for LLVMs code coverage
instrumentation
2020-08-31 22:57:55 -07:00
Tyler Mandry
6d834a4046
Rollup merge of #76002 - richkadel:llvm-coverage-map-gen-6b.3, r=tmandry
Fix `-Z instrument-coverage` on MSVC

Found that `-C link-dead-code` (which was enabled automatically
under `-Z instrument-coverage`) was causing the linking error that
resulted in segmentation faults in coverage instrumented binaries. Link
dead code is now disabled under MSVC, allowing `-Z instrument-coverage`
to be enabled under MSVC for the first time.

More details are included in Issue #76038 .

Note this PR makes it possible to support `Z instrument-coverage` but
does not enable instrument coverage for MSVC in existing tests. It will be
enabled in another PR to follow this one (both PRs coming from original
PR #75828).

r? @tmandry
FYI: @wesleywiser
2020-08-31 19:18:14 -07:00
Rich Kadel
ddb054aee8 Fix -Z instrument-coverage on MSVC
Found that -C link-dead-code (which was enabled automatically
under -Z instrument-coverage) was causing the linking error that
resulted in segmentation faults in coverage instrumented binaries. Link
dead code is now disabled under MSVC, allowing `-Z instrument-coverage`
to be enabled under MSVC for the first time.

More details are included in Issue #76038.

(This PR was broken out from PR #75828)
2020-08-31 18:41:13 -07:00
Dylan MacKenzie
b015109ba9 Add documentation to the Analysis traits 2020-08-30 14:26:04 -07:00
Dylan MacKenzie
e178a87036 Expand documentation for the lattice module 2020-08-30 13:27:07 -07:00
Dylan MacKenzie
c03eba2d08 Add FIXME for faster cached block transfer functions
I've tried a few ways of implementing this, but each fell short.

Adding an auxiliary `_Idx` associated type to `Analysis` that defaults
to `!` but is overridden in the blanket impl of `Analysis` for `A:
GenKillAnalysis` to `A::Idx` seems promising, but the trait solver is
unable to prove equivalence between `A::Idx` and `A::_Idx` within the
overridden version of `into_engine`. Without full-featured
specialization, removing `into_engine` or splitting it into a different
trait would have a significant ergonomic penalty.

Alternatively, we could erase the index type and store a
`GenKillSet<u32>` as well as a function pointer for transmuting between
`&mut A::Domain` and `&mut BitSet<u32>` in the hopes that LLVM can
devirtualize a simple function pointer better than the boxed closure.
However, this is brittle, requires `unsafe` code, and doesn't work for
index types that aren't the same size as a `u32` (e.g. `usize`) since
`GenKillSet` stores a `HybridBitSet`, which may be a `Vec<I>`. Perhaps
safe transmute could help here?
2020-08-30 11:15:25 -07:00
Dylan MacKenzie
b19b8ea611 Update dataflow analyses to use new interface 2020-08-30 11:15:25 -07:00
Dylan MacKenzie
3233fb18a8 Extend dataflow framework to support arbitrary lattices 2020-08-30 11:15:24 -07:00
Dylan MacKenzie
9e45e90596 Allow access to the underlying Results from a ResultsCursor 2020-08-30 11:15:24 -07:00
Dylan MacKenzie
a88dc37c54 Add regex dependency to librustc_mir 2020-08-30 11:15:21 -07:00
David Wood
6ff471b1cf
ty: remove obsolete printer
This commit removes the obsolete printer and replaces all uses of it
with `FmtPrinter`. Of the replaced uses, all but one use was in `debug!`
logging, two cases were notable:

- `MonoItem::to_string` is used in `-Z print-mono-items` and therefore
  affects the output of all codegen-units tests.
- `DefPathBasedNames` was used in `librustc_codegen_llvm/type_of.rs`
  with `LLVMStructCreateNamed` and that'll now get different values, but
  this should result in no functional change.

Signed-off-by: David Wood <david@davidtw.co>
2020-08-30 18:59:07 +01:00
mark
9e5f7d5631 mv compiler to compiler/ 2020-08-30 18:45:07 +03:00