librustc: Improve method autoderef/deref/index behavior more, and enable IndexMut on mutable vectors.
This fixes a bug whereby the mutability fixups for method behavior were
not kicking in after autoderef failed to happen at any level. It also
adds support for `Index` to the fixer-upper.
Closes#12825.
r? @pnkfelix
LLVM generates wrong code (which may be an instance of compile-time UB) when
faced with types that take lots of memory - bigger than the address space.
Make using such types a trans error. While trans errors are bad, overbig
types are expected to be very rare.
Use the integer sizes LLVM uses, rather than having random projections
laying around. Sizes are u64, Alignments are u32, C_*int is target-dependent
but 64-bit is fine (the int -> C_int conversion is non-precision-losing,
but it can be preceded by `as int` conversions which are, so it is
somewhat ugly. However, being able to suffix a `u` to properly infer
integer types is nice).
The array is the fundamental concept; vectors are growable arrays, and
slices are views into either. Show common array ops up front: length
and iteration. Mention arrays are immutable by default. Highlight
definite initialization and bounds-checking as safety features. Show
that you only need a type suffix on one element of initializers.
Explain that vectors are a value-add library type over arrays, not a
fundamental type; show they have the same "interface." Motivate slices
as efficient views into arrays; explain you can slice vectors, Strings,
&str because they're backed by arrays. Show off new, easy-to-read
[a..b] slice syntax.
Previously it had some uninituitive conditionals due to the interaction
with the Rand construction and Clone reinitialisation to create
sequential identifying numbers. This replaces all that with just
constructing the DropCounters with the appropriate identifiers.
[RFC 344](https://github.com/rust-lang/rfcs/pull/344) proposes a set of naming conventions for lints. This PR
renames existing lints to follow the conventions.
Use the following sed script to bring your code up to date:
```
s/unnecessary_typecast/unused_typecasts/g
s/unsigned_negate/unsigned_negation/g
s/type_limits/unused_comparisons/g
s/type_overflow/overflowing_literals/g
s/ctypes/improper_ctypes/g
s/owned_heap_memory/box_pointers/g
s/unused_attribute/unused_attributes/g
s/path_statement/path_statements/g
s/unused_must_use/unused_must_use/g
s/unused_result/unused_results/g
s/non_uppercase_statics/non_upper_case_globals/g
s/unnecessary_parens/unused_parens/g
s/unnecessary_import_braces/unused_import_braces/g
s/unused_unsafe/unused_unsafe/g
s/unsafe_block/unsafe_blocks/g
s/unused_mut/unused_mut/g
s/unnecessary_allocation/unused_allocation/g
s/missing_doc/missing_docs/g
s/unused_imports/unused_imports/g
s/unused_extern_crate/unused_extern_crates/g
s/unnecessary_qualification/unused_qualifications/g
s/unrecognized_lint/unknown_lints/g
s/unused_variable/unused_variables/g
s/dead_assignment/unused_assignments/g
s/unknown_crate_type/unknown_crate_types/g
s/variant_size_difference/variant_size_differences/g
s/transmute_fat_ptr/fat_ptr_transmutes/g
```
Since a large number of lints are being renamed for RFC 344, this PR
adds some basic deprecation/renaming functionality to the pluggable lint
system. It allows a simple mapping of old to new names, and can warn
when old names are being used.
This change needs to be rolled out in stages. In this PR, the
deprecation warning is commented out, but the old name is forwarded to
the new one.
Once the PR lands and we have generated a new snapshot of the
compiler, we can add the deprecation warning and rename all uses of the
lints in the rust codebase. I will file a PR to do so.
Closes#16545Closes#17932
r? @pcwalton
The array is the fundamental concept; vectors are growable arrays, and
slices are views into either. Show common array ops up front: length
and iteration. Mention arrays are immutable by default. Highlight
definite initialization and bounds-checking as safety features. Show
that you only need a type suffix on one element of initializers.
Explain that vectors are a value-add library type over arrays, not a
fundamental type; show they have the same "interface." Motivate slices
as efficient views into arrays; explain you can slice vectors, Strings,
&str because they're backed by arrays.
Since a large number of lints are being renamed for RFC 344, this commit
adds some basic deprecation/renaming functionality to the pluggable lint
system. It allows a simple mapping of old to new names, and can warn
when old names are being used.
This change needs to be rolled out in stages. In this commit, the
deprecation warning is commented out, but the old name is forwarded to
the new one.
Once the commit lands and we have generated a new snapshot of the
compiler, we can add the deprecation warning and rename all uses of the
lints in the rust codebase.
RFC 344 proposes a set of naming conventions for lints. This commit
renames existing lints to follow the conventions.
Use the following sed script to bring your code up to date:
```
s/unnecessary_typecast/unused_typecasts/g
s/unsigned_negate/unsigned_negation/g
s/type_limits/unused_comparisons/g
s/type_overflow/overflowing_literals/g
s/ctypes/improper_ctypes/g
s/owned_heap_memory/box_pointers/g
s/unused_attribute/unused_attributes/g
s/path_statement/path_statements/g
s/unused_must_use/unused_must_use/g
s/unused_result/unused_results/g
s/non_uppercase_statics/non_upper_case_globals/g
s/unnecessary_parens/unused_parens/g
s/unnecessary_import_braces/unused_import_braces/g
s/unused_unsafe/unused_unsafe/g
s/unsafe_block/unsafe_blocks/g
s/unused_mut/unused_mut/g
s/unnecessary_allocation/unused_allocation/g
s/missing_doc/missing_docs/g
s/unused_imports/unused_imports/g
s/unused_extern_crate/unused_extern_crates/g
s/unnecessary_qualification/unused_qualifications/g
s/unrecognized_lint/unknown_lints/g
s/unused_variable/unused_variables/g
s/dead_assignment/unused_assignments/g
s/unknown_crate_type/unknown_crate_types/g
s/variant_size_difference/variant_size_differences/g
s/transmute_fat_ptr/fat_ptr_transmutes/g
```
Closes#16545Closes#17932
Due to deprecation, this is a:
[breaking-change]
`IndexMut` on mutable vectors.
This fixes a bug whereby the mutability fixups for method behavior were
not kicking in after autoderef failed to happen at any level. It also
adds support for `Index` to the fixer-upper.
Closes#12825.
