fba2287c54
The sample program in cranelift/filetests/src/function_runner.rs would abort with an mprotect failure under certain circumstances, see https://github.com/bytecodealliance/wasmtime/pull/4453#issuecomment-1303803222 Root cause was that enabling PROT_EXEC on the main process heap may be prohibited, depending on Linux distro and version. This only shows up in the doc test sample program because the main clif-util is multi-threaded and therefore allocations will happen on glibc's per-thread heap, which is allocated via mmap, and not the main process heap. Work around the problem by enabling the "selinux-fix" feature of the cranelift-jit crate dependency in the filetests. Note that this didn't compile out of the box, so a separate fix is also required and provided as part of this PR. Going forward, it would be preferable to always use mmap to allocate the backing memory for JITted code.
filetests
Filetests is a crate that contains multiple test suites for testing
various parts of cranelift. Each folder under cranelift/filetests/filetests is a different
test suite that tests different parts.
Adding a runtest
One of the available testsuites is the "runtest" testsuite. Its goal is to compile some piece of clif code, run it and ensure that what comes out is what we expect.
To build a run test you can add the following to a file:
test interpret
test run
target x86_64
target aarch64
target s390x
function %band_f32(f32, f32) -> f32 {
block0(v0: f32, v1: f32):
v2 = band v0, v1
return v2
}
; run: %band_f32(0x0.5, 0x1.0) == 0x1.5
Since this is a run test for band we can put it in: runtests/band.clif.
Once we have the file in the test suite we can run it by invoking: cargo run -- test filetests/filetests/runtests/band.clif from the cranelift directory.
The first lines tell clif-util what kind of tests we want to run on this file.
test interpret invokes the interpreter and checks if the conditions in the ; run comments pass. test run does the same, but compiles the file and runs it as a native binary.
For more information about testing see testing.md.