Use literal 5 instead of five in book section 4.1
The other two code snippets in this sentence are valid code, so it makes more sense to use the literal `5` rather than the invalid symbol `five`.
Delay error reporting of filename mismatch.
When cross compiling with procedural macros, the crate loader starts by
looking for a target crate, before trying with a host crate.
Rather than emitting an error immediately if the host and target
extension differ, the compiler should delay it until both attempts have
failed.
Fixes#37899
[LLVM 4.0] OptimizationDiagnostic FFI forward compatibility
- getMsg() changed to return std::string by-value. Fix: copy the data to a rust String during unpacking.
- getPassName() changed to return StringRef
cc #37609
std: make compilation of libpanic_unwind optional via a Cargo feature
with this feature disabled, you can (Cargo) compile std with
"panic=abort"
rustbuild will build std with this feature enabled, to maintain the
status quo
fixes#37252
r? @alexcrichton
When cross compiling with procedural macros, the crate loader starts by
looking for a target crate, before trying with a host crate.
Rather than emitting an error immediately if the host and target
extension differ, the compiler should delay it until both attempts have
failed.
Fixes#37899
r? @jseyfried
Forward ExactSizeIterator::len and is_empty for important iterator adaptors
Forward ExactSizeIterator::len and is_empty for important iterator adaptors
Because some iterators will provide improved version of len and/or is_empty,
adaptors should forward to those implementations if possible.
Add debug flag `-Z print-type-sizes` for instrumention type/variant sizes
Add debug flag `-Z print-type-sizes` for instrumention type/variant sizes
This is meant to help with things like #36799 in a very local way; namely, once you have a hypothesis as to which types have a large population or are "too large", you can use `-Z print-type-sizes` to learn how large each type is, and how much each variant in an enum contributes to the size of that overall enum.
Note that the tests have been updated to initialize the local
variables; originally it was enough just to declare them.
Back when I started this, the `layout_cache` contained entries even
just for types that had been declared but not initialized. Apparently
things have changed in the interim so that if I want one of those
layouts to be computed, I need to actually initialize the value.
(Incidentally, this shows a weakness in the strategy of just walking
the `layout_cache`; the original strategy of using a MIR visitor would
probably have exhibited more robustness in terms of consistent output,
but it had other weaknesses so I chose not to reimplement it. At
least, not yet.)
----
Also, I have updated tests to avoid target-specific alignments.
Biggest change: Revised print-type-sizes output to include breakdown
of layout.
Includes info about field sizes (and alignment + padding when padding
is injected; the injected padding is derived from the offsets computed
by layout module).
Output format is illustrated in commit that has the ui tests.
Note: there exists (at least) one case of variant w/o name: empty
enums. Namely, empty enums use anonymous univariant repr. So for such
cases, print the number of the variant instead of the name.
----
Also, eddyb suggested of reading from `layout_cache` post-trans.
(For casual readers: the compiler source often uses the word "cache"
for tables that are in fact not periodically purged, and thus are
useful as the basis for data like this.)
Some types that were previously not printed are now included in the
output. (See e.g. the tests `print_type_sizes/generics.rs` and
`print_type_sizes/variants.rs`)
----
Other review feedback:
switch to an exhaustive match when filtering in just structural types.
switch to hashset for layout info and move sort into print method.
----
Driveby change: Factored session::code_stats into its own module
----
incorporate njn feedback re output formatting.
rustdoc: separate test collection from the main "clean"-ing pipeline.
While reusing the documentation "clean"-ing infrastructure for collecting code examples to test may have seemed appealing at some point, doing the same through a HIR visitor is barely any harder.
At the same time, supporting both "regular documentation" and "test collection" modes in `rustdoc::clean` has its cost, requiring any use of a `TyCtxt` to be speculative, and provide some sort of fallback.
This simplification is the first step towards bringing rustdoc closer to the compiler, and perhaps even unifying the "local crate" (based on the HIR AST) and "inlinined across crates" (based on crate metadata and typesystem information) implementations of rustdoc.
Sadly, not all possible changes to rustdoc will be uncontroversial, so I'm starting small with this patch.
with this feature disabled, you can (Cargo) compile std with
"panic=abort"
rustbuild will build std with this feature enabled, to maintain the
status quo
fixes#37252
rustc_metadata: don't break the version check when CrateRoot changes.
In #36551 I made `rustc_version` a field of `CrateRoot`, but despite it being the first field, one could still break the version check by changing `CrateRoot` so older compilers couldn't fully decode it (e.g. #37463).
This PR fixes#37803 by moving the version string back at the beginning of metadata, right after the 32-bit big-endian absolute position of `CrateRoot`, and by incrementing `METADATA_VERSION`.
Expand is_uninhabited
This allows code such as this to compile:
``` rust
let x: ! = ...;
match x {};
let y: (u32, !) = ...;
match y {};
```
@eddyb You were worried about making this change. Do you have any idea about what could break? Are there any special tests that need to be written for it?
