cfg(version): treat nightlies as complete
This PR makes cfg(version) treat the nightlies
for version 1.n.0 as 1.n.0, even though that nightly
version might not have all stabilizations and features
of the released 1.n.0. This is done for greater
convenience for people who want to test a newly
stabilized feature on nightly, or in other words,
give newly stabilized features as many eyeballs
as possible.
For users who wish to pin nightlies, this commit adds
a -Z assume-incomplete-release option that they can
enable if they run into any issues due to this change.
Implements the suggestion in https://github.com/rust-lang/rust/issues/64796#issuecomment-640851454
This commit makes cfg(version) treat the nightlies
for version 1.n.0 as 1.n.0, even though that nightly
version might not have all stabilizations and features
of the released 1.n.0. This is done for greater
convenience for people who want to test a newly
stabilized feature on nightly.
For users who wish to pin nightlies, this commit adds
a -Z assume-incomplete-release option that they can
enable if there are any issues due to this change.
This commit adds a new stable codegen option to rustc,
`-Csplit-debuginfo`. The old `-Zrun-dsymutil` flag is deleted and now
subsumed by this stable flag. Additionally `-Zsplit-dwarf` is also
subsumed by this flag but still requires `-Zunstable-options` to
actually activate. The `-Csplit-debuginfo` flag takes one of
three values:
* `off` - This indicates that split-debuginfo from the final artifact is
not desired. This is not supported on Windows and is the default on
Unix platforms except macOS. On macOS this means that `dsymutil` is
not executed.
* `packed` - This means that debuginfo is desired in one location
separate from the main executable. This is the default on Windows
(`*.pdb`) and macOS (`*.dSYM`). On other Unix platforms this subsumes
`-Zsplit-dwarf=single` and produces a `*.dwp` file.
* `unpacked` - This means that debuginfo will be roughly equivalent to
object files, meaning that it's throughout the build directory
rather than in one location (often the fastest for local development).
This is not the default on any platform and is not supported on Windows.
Each target can indicate its own default preference for how debuginfo is
handled. Almost all platforms default to `off` except for Windows and
macOS which default to `packed` for historical reasons.
Some equivalencies for previous unstable flags with the new flags are:
* `-Zrun-dsymutil=yes` -> `-Csplit-debuginfo=packed`
* `-Zrun-dsymutil=no` -> `-Csplit-debuginfo=unpacked`
* `-Zsplit-dwarf=single` -> `-Csplit-debuginfo=packed`
* `-Zsplit-dwarf=split` -> `-Csplit-debuginfo=unpacked`
Note that `-Csplit-debuginfo` still requires `-Zunstable-options` for
non-macOS platforms since split-dwarf support was *just* implemented in
rustc.
There's some more rationale listed on #79361, but the main gist of the
motivation for this commit is that `dsymutil` can take quite a long time
to execute in debug builds and provides little benefit. This means that
incremental compile times appear that much worse on macOS because the
compiler is constantly running `dsymutil` over every single binary it
produces during `cargo build` (even build scripts!). Ideally rustc would
switch to not running `dsymutil` by default, but that's a problem left
to get tackled another day.
Closes#79361
Adds checks for:
* `no_core` attribute
* explicitly-enabled `legacy` symbol mangling
* mir_opt_level > 1 (which enables inlining)
I removed code from the `Inline` MIR pass that forcibly disabled
inlining if `-Zinstrument-coverage` was set. The default `mir_opt_level`
does not enable inlining anyway. But if the level is explicitly set and
is greater than 1, I issue a warning.
The new warnings show up in tests, which is much better for diagnosing
potential option conflicts in these cases.
Fixes multiple issue with counters, with simplification
Includes a change to the implicit else span in ast_lowering, so coverage
of the implicit else no longer spans the `then` block.
Adds coverage for unused closures and async function bodies.
Fixes: #78542
Adding unreachable regions for known MIR missing from coverage map
Cleaned up PR commits, and removed link-dead-code requirement and tests
Coverage no longer depends on Issue #76038 (`-C link-dead-code` is
no longer needed or enforced, so MSVC can use the same tests as
Linux and MacOS now)
Restrict adding unreachable regions to covered files
Improved the code that adds coverage for uncalled functions (with MIR
but not-codegenned) to avoid generating coverage in files not already
included in the files with covered functions.
Resolved last known issue requiring --emit llvm-ir workaround
Fixed bugs in how unreachable code spans were added.
Allow disabling TrapUnreachable via -Ztrap-unreachable=no
Currently this is only possible by defining a custom target, which is quite unwieldy.
This is useful for embedded targets where small code size is desired. For example, on my project (thumbv7em-none-eabi) this yields a 0.6% code size reduction: 132892 bytes -> 132122 bytes (770 bytes down).
This is useful for embedded targets where small code size is desired.
For example, on my project (thumbv7em-none-eabi) this yields a 0.6% code size reduction.
Change `-Z fewer-names` into an optional boolean flag and allow using it
to either discard value names when true or retain them when false,
regardless of other settings.
* `-Zinline-mir-threshold` to change the default threshold.
* `-Zinline-mir-hint-threshold` to change the threshold used by
functions with inline hint.
Add support for SHA256 source file hashing
Adds support for `-Z src-hash-algorithm sha256`, which became available in LLVM 11.
Using an older version of LLVM will cause an error `invalid checksum kind` if the hash algorithm is set to sha256.
r? `@eddyb`
cc #70401 `@est31`
Add option to customize the nll-facts' folder location
This PR adds a `nll-facts-dir` option to specify the location of the directory in which NLL facts are dumped into. It works the same way `dump-mir-dir` controls the location used by the `dump-mir` option.
Implement -Z relax-elf-relocations=yes|no
This lets rustc users tweak whether the linker should relax ELF relocations without recompiling a whole new target with its own libcore etc.
This lets rustc users tweak whether the linker should relax ELF relocations,
namely whether it should emit R_X86_64_GOTPCRELX relocations instead of
R_X86_64_GOTPCREL, as the former is allowed by the ABI to be further
optimised. The default value is whatever the target defines.
This lets rustc users tweak whether all functions should be put in their own
TEXT section, using whatever default value the target defines if the flag
is missing.
This is a combination of 18 commits.
Commit #2:
Additional examples and some small improvements.
Commit #3:
fixed mir-opt non-mir extensions and spanview title elements
Corrected a fairly recent assumption in runtest.rs that all MIR dump
files end in .mir. (It was appending .mir to the graphviz .dot and
spanview .html file names when generating blessed output files. That
also left outdated files in the baseline alongside the files with the
incorrect names, which I've now removed.)
Updated spanview HTML title elements to match their content, replacing a
hardcoded and incorrect name that was left in accidentally when
originally submitted.
Commit #4:
added more test examples
also improved Makefiles with support for non-zero exit status and to
force validation of tests unless a specific test overrides it with a
specific comment.
Commit #5:
Fixed rare issues after testing on real-world crate
Commit #6:
Addressed PR feedback, and removed temporary -Zexperimental-coverage
-Zinstrument-coverage once again supports the latest capabilities of
LLVM instrprof coverage instrumentation.
Also fixed a bug in spanview.
Commit #7:
Fix closure handling, add tests for closures and inner items
And cleaned up other tests for consistency, and to make it more clear
where spans start/end by breaking up lines.
Commit #8:
renamed "typical" test results "expected"
Now that the `llvm-cov show` tests are improved to normally expect
matching actuals, and to allow individual tests to override that
expectation.
Commit #9:
test coverage of inline generic struct function
Commit #10:
Addressed review feedback
* Removed unnecessary Unreachable filter.
* Replaced a match wildcard with remining variants.
* Added more comments to help clarify the role of successors() in the
CFG traversal
Commit #11:
refactoring based on feedback
* refactored `fn coverage_spans()`.
* changed the way I expand an empty coverage span to improve performance
* fixed a typo that I had accidently left in, in visit.rs
Commit #12:
Optimized use of SourceMap and SourceFile
Commit #13:
Fixed a regression, and synched with upstream
Some generated test file names changed due to some new change upstream.
Commit #14:
Stripping out crate disambiguators from demangled names
These can vary depending on the test platform.
Commit #15:
Ignore llvm-cov show diff on test with generics, expand IO error message
Tests with generics produce llvm-cov show results with demangled names
that can include an unstable "crate disambiguator" (hex value). The
value changes when run in the Rust CI Windows environment. I added a sed
filter to strip them out (in a prior commit), but sed also appears to
fail in the same environment. Until I can figure out a workaround, I'm
just going to ignore this specific test result. I added a FIXME to
follow up later, but it's not that critical.
I also saw an error with Windows GNU, but the IO error did not
specify a path for the directory or file that triggered the error. I
updated the error messages to provide more info for next, time but also
noticed some other tests with similar steps did not fail. Looks
spurious.
Commit #16:
Modify rust-demangler to strip disambiguators by default
Commit #17:
Remove std::process::exit from coverage tests
Due to Issue #77553, programs that call std::process::exit() do not
generate coverage results on Windows MSVC.
Commit #18:
fix: test file paths exceeding Windows max path len
Make graphviz font configurable
Alternative to PR #76776.
To change the graphviz output to use an alternative `fontname` value,
add a command line option like: `rustc --graphviz-font=monospace`.
r? @ecstatic-morse
Alternative to PR ##76776.
To change the graphviz output to use an alternative `fontname` value,
add a command line option like: `rustc --graphviz-font=monospace`.
Many developers use a dark theme with editors and IDEs, but this
typically doesn't extend to graphviz output.
When I bring up a MIR graphviz document, the white background is
strikingly bright. This new option changes the colors used for graphviz
output to work better in dark-themed UIs.
Tools, tests, and experimenting with MIR-derived coverage counters
Leverages the new mir_dump output file in HTML+CSS (from #76074) to visualize coverage code regions
and the MIR features that they came from (including overlapping spans).
See example below.
The `run-make-fulldeps/instrument-coverage` test has been refactored to maximize test coverage and reduce code duplication. The new tests support testing with and without `-Clink-dead-code`, so Rust coverage can be tested on MSVC (which, currently, only works with `link-dead-code` _disabled_).
New tests validate coverage region generation and coverage reports with multiple counters per function. Starting with a simple `if-else` branch tests, coverage tests for each additional syntax type can be added by simply dropping in a new Rust sample program.
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 two of those other PRs: #76002, #76003 and #76074
Rust compiler MCP rust-lang/compiler-team#278
Relevant issue: #34701 - Implement support for LLVMs code coverage
instrumentation
r? @tmandry
FYI: @wesleywiser
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
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.
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
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
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)
Fixes#75050
Previously, we would unconditionally suppress the panic hook during
proc-macro execution. This commit adds a new flag
-Z proc-macro-backtrace, which allows running the panic hook for
easier debugging.
