Commit Graph

666 Commits

Author SHA1 Message Date
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