This is the conceptual opposite of the rust-cold calling convention and
is particularly useful in combination with the new `explicit_tail_calls`
feature.
For relatively tight loops implemented with tail calling (`become`) each
of the function with the regular calling convention is still responsible
for restoring the initial value of the preserved registers. So it is not
unusual to end up with a situation where each step in the tail call loop
is spilling and reloading registers, along the lines of:
foo:
push r12
; do things
pop r12
jmp next_step
This adds up quickly, especially when most of the clobberable registers
are already used to pass arguments or other uses.
I was thinking of making the name of this ABI a little less LLVM-derived
and more like a conceptual inverse of `rust-cold`, but could not come
with a great name (`rust-cold` is itself not a great name: cold in what
context? from which perspective? is it supposed to mean that the
function is rarely called?)
Move the libgccjit.so file in a target directory
Since GCC is not multi-target, we need multiple libgccjit.so. Our solution to have a directory per target so that we can have multiple libgccjit.so.
r? `@Kobzol`
Tests for `-Zdebuginfo-compression=zstd` need to be skipped if LLVM was built
without support for zstd compression.
Currently, compiletest relies on messy and fragile heuristics to detect whether
the compiler's LLVM was built with zstd support. But the compiler itself
already knows whether LLVM has zstd or not, so it's easier for compiletest to
just ask the compiler.
This schema is helpful for people writing custom target spec JSON. It
can provide autocomplete in the editor, and also serves as documentation
when there are documentation comments on the structs, as `schemars` will
put them in the schema.
This test depends on the target-specific behavior of crt-static for musl
targets. However, running the testsuite on a musl host requires
setting `crt-static` to `false`, as it wouldn't otherwise be possible to
build rustc. This in turn will enable `-Ctarget-feature=-crt-static` for
all tests, mismatching the expected `+crt-static` for the musl target
tested in this testcase.
Since this test specifically tests the default value of `crt-static` for
the musl target, ignoring it entirely makes more sense than manually
setting `-Ctarget-feature=+crt-static` here, but both would be valid
approaches.
Signed-off-by: Jens Reidel <adrian@travitia.xyz>
In a PR to emit warnings on misuse of `--print native-static-libs`,
we did not consider the matter of composing parts of build systems.
If you are not directly invoking rustc, it can be difficult to know
when you will in fact compile a staticlib, so making sure everyone
uses `--print native-static-lib` correctly can be just a nuisance.
This reverts the following commits:
- f66787a08d
- 72a9219e82
- 98bb597c05
- c59b70841c
Next cycle we can reland a slightly more narrowly focused variant or one
that focuses on `--emit` instead of `--print native-static-libs`.
But in its current state, I am not sure the warning is very useful.
- Document test intent to check for `-Whelp` suggestion if
`--print=lints` was specified.
- Move this test under `tests/ui/print-request/` and rename it to
`print-lints-help.rs` to better reflect what it is checking.
I can't find any dedicated tests that actually exercises the stability
gating (via `-Z unstable-options`) of print requests, so here's a
dedicated one.
I coalesced `tests/ui/feature-gates/feature-gate-print-check-cfg.rs`
into this test, because AFAICT that print request is not feature gated,
but only `-Z unstable-options`-gated just like other unstable print
requests.
The deployment target environment variable is OS-specific, and if you're
in a place where you're asking `rustc` for the deployment target, you're
likely to also wanna know the environment variable.
