Always format to internal String in FmtPrinter
This avoids monomorphizing for different parameters, decreasing generic code
instantiated downstream from rustc_middle -- locally seeing 7% unoptimized LLVM IR
line wins on rustc_borrowck, for example.
We likely can't/shouldn't get rid of the Result-ness on most functions, though some
further cleanup avoiding fmt::Error where we now know it won't occur may be possible,
though somewhat painful -- fmt::Write is a pretty annoying API to work with in practice
when you're trying to use it infallibly.
Partially move cg_ssa towards using a single builder
Not all codegen backends can handle hopping between blocks well. For example Cranelift requires blocks to be terminated before switching to building a new block. Rust-gpu requires a `RefCell` to allow hopping between blocks and cg_gcc currently has a buggy implementation of hopping between blocks. This PR reduces the amount of cases where cg_ssa switches between blocks before they are finished and mostly fixes the block hopping in cg_gcc. (~~only `scalar_to_backend` doesn't handle it correctly yet in cg_gcc~~ fixed that one.)
`@antoyo` please review the cg_gcc changes.
remove feature gate in control_flow examples
Stabilization was done in https://github.com/rust-lang/rust/pull/91091, but the two examples weren't updated accordingly.
Probably too late to put it into stable, but it should be in the next release :)
Miri: relax fn ptr check
As discussed in https://github.com/rust-lang/unsafe-code-guidelines/issues/72#issuecomment-1025407536, the function pointer check done by Miri is currently overeager: contrary to our usual principle of only checking rather uncontroversial validity invariants, we actually check that the pointer points to a real function.
So, this relaxes the check to what the validity invariant probably will be (and what the reference already says it is): the function pointer must be non-null, and that's it.
The check that CTFE does on the final value of a constant is unchanged -- CTFE recurses through references, so it makes some sense to also recurse through function pointers. We might still want to relax this in the future, but that would be a separate change.
r? `@oli-obk`
Change `char` type in debuginfo to DW_ATE_UTF
Rust previously encoded the `char` type as DW_ATE_unsigned_char. The more appropriate encoding is `DW_ATE_UTF`.
Clang also uses the DW_ATE_UTF for `char32_t` in C++.
This fixes the display of the `char` type in the Windows debuggers. Without this change, the variable did not show in the locals window.
LLDB 13 is also able to display the char value, when before it failed with `need to add support for DW_TAG_base_type 'char' encoded with DW_ATE = 0x8, bit_size = 32`
r? `@wesleywiser`
`scan_escape` currently has a fast path (for when the first char isn't
'\\') and a slow path.
This commit changes `scan_escape` so it only handles the slow path, i.e.
the actual escaping code. The fast path is inlined into the two call
sites.
This change makes the code faster, because there is no function call
overhead on the fast path. (`scan_escape` is a big function and doesn't
get inlined.)
This change also improves readability, because it removes a bunch of
mode checks on the the fast paths.
False positive redundant_closure when using ref pattern in closure params
fixes#8460
Fixed [redundant_closure] so that closures of which params bound as `ref` or `ref mut ` doesn't trigger the lint.
(e.g. `|ref x| some_expr` doesn't trigger the lint.)
changelog: none
Rust previously encoded the `char` type as DW_ATE_unsigned_char. The more
appropriate encoding is DW_ATE_UTF.
Clang uses this same debug encoding for char32_t.
This fixes the display of `char` types in Windows debuggers as well as LLDB.
