Ignore `branch-protection-check-IBT` run-make test
The old Makefile implementation (#110304) had an improper comparison which caused the test to never run. However, both the updated Makefile implementation and the rmake implementation fail (missing `.note.gnu.property`). This could be a bug in the original implementation or test flakiness.
Edit: Manually recreating the test case shows that `.note.gnu.property` does not appear in nightly.
```rust
// main.rs
fn main() {
println!("hello world");
}
```
```sh
$ rustc +nightly -V
rustc 1.81.0-nightly (c1b336cb6 2024-06-21)
$ rustc +stable -V
rustc 1.79.0 (129f3b996 2024-06-10)
```
```sh
$ rustc +nightly -Zcf-protection=branch -Clink-args=-nostartfiles -Csave-temps "-L$PWD" main.rs -o main
$ llvm-readobj --elf-output-style=GNU -nW main
Displaying notes found in: .note.gnu.build-id
Owner Data size Description
GNU 0x00000008 NT_GNU_BUILD_ID (unique build ID bitstring)
Build ID: bcae34e6431b2a37
```
Compiling without the other flags still does not show `.note.gnu.property`.
```sh
$ rustc +nightly main.rs -o main
$ llvm-readobj --elf-output-style=GNU -nW main
Displaying notes found in: .note.ABI-tag
Owner Data size Description
GNU 0x00000010 NT_GNU_ABI_TAG (ABI version tag)
OS: Linux, ABI: 4.4.0
Displaying notes found in: .note.gnu.build-id
Owner Data size Description
GNU 0x00000008 NT_GNU_BUILD_ID (unique build ID bitstring)
Build ID: d60d5f108b63bf3a
```
Compiling on stable shows `.note.gnu.property`.
```sh
$ rustc +stable main.rs -o main
$ llvm-readobj --elf-output-style=GNU -nW main
Displaying notes found in: .note.gnu.property
Owner Data size Description
GNU 0x00000010 NT_GNU_PROPERTY_TYPE_0 (property note)
Properties: x86 ISA needed: x86-64-baseline
Displaying notes found in: .note.gnu.build-id
Owner Data size Description
GNU 0x00000014 NT_GNU_BUILD_ID (unique build ID bitstring)
Build ID: 4a494eb578123314e6ff1caf1c8877e27004664f
Displaying notes found in: .note.ABI-tag
Owner Data size Description
GNU 0x00000010 NT_GNU_ABI_TAG (ABI version tag)
OS: Linux, ABI: 4.4.0
```
Part of #121876.
r? `@jieyouxu`
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.rs version: this allows run-make tests to be written in Rust
(with rmake.rs as the main test file).
The legacy Makefile version: this is what run-make tests were written with
before support for rmake.rs was 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_support library 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 within build/<target>/test/run-make/
<test-name>/
rmake.exe # recipe binary
rmake_out/ # sources from test sources copied over
and copy non-rmake.rs input support files over to rmake_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.
4a94e8089d