ebff167966
Regression test for AVR `rjmp` offset This adds a regression test for #129301 by minimizing the code in the linked issue and putting it into a `#![no_core]`-compatible format, so that it can easily be used within an `rmake`-test. This needs to be a `rmake` test (opposed to a `tests/assembly` one), since the linked issue describes, that the problem only occurs if the code is directly compiled. Note, that `lld` is used instead of `avr-gcc`; see the [comments](https://github.com/rust-lang/rust/pull/131755#issuecomment-2416469675) [below](https://github.com/rust-lang/rust/pull/131755#issuecomment-2417160045). Closes #129301. To show, that the test actually catches the wrong behavior, this can be tested with a faulty rustc: ```bash $ rustup install nightly-2024-08-19 $ rustc +nightly-2024-08-19 -C opt-level=s -C panic=abort --target avr-unknown-gnu-atmega328 -Clinker=build/x86_64-unknown-linux-gnu/ci-llvm/bin/lld -Clink-arg='--entry=main' -o compiled tests/run-make/avr-rjmp-offset/avr-rjmp-offsets.rs $ llvm-objdump -d compiled | grep '<main>' -A 6 000110b4 <main>: 110b4: 81 e0 ldi r24, 0x1 110b6: 92 e0 ldi r25, 0x2 110b8: 85 b9 out 0x5, r24 110ba: 95 b9 out 0x5, r25 110bc: fe cf rjmp .-4 ``` One can see, that the wrong label offset (`4` instead of `6`) is produced, which would trigger an assertion in the test case. This would be a good candidate for using the `minicore` proposed in #130693. Since this is not yet merged, there is a FIXME. r? Patryk27 I think, you are the yet-to-be official target maintainer, hence I'll assign to you. `@rustbot` label +O-AVR
The run-make test suite
The run-make test suite contains tests which are the most flexible out of all
the rust-lang/rust test suites. run-make
tests can basically contain arbitrary code, and are supported by the
run_make_support library.
Infrastructure
There are two kinds of run-make tests:
- The new
rmake.rsversion: this allows run-make tests to be written in Rust (withrmake.rsas the main test file). - The legacy
Makefileversion: this is what run-make tests were written with before support forrmake.rswas introduced.
The implementation for collecting and building the rmake.rs recipes (or
Makefiles) are in
src/tools/compiletest/src/runtest.rs,
in run_rmake_v2_test and run_rmake_legacy_test.
Rust-based run-make tests: rmake.rs
The setup for the rmake.rs version is a 3-stage process:
-
First, we build the
run_make_supportlibrary in bootstrap as a tool lib. -
Then, we compile the
rmake.rs"recipe" linking the support library and its dependencies in, and provide a bunch of env vars. We setup a directory structure withinbuild/<target>/test/run-make/<test-name>/ rmake.exe # recipe binary rmake_out/ # sources from test sources copied overand copy non-
rmake.rsinput support files over tormake_out/. The support library is made available as an extern prelude. -
Finally, we run the recipe binary and set
rmake_out/as the working directory.
Formatting
Note that files under tests/ are not formatted by ./x fmt,
use rustfmt tests/path/to/file.rs to format a specific file if desired.