Add a basic unit test for the new libclamav_rust `logging.rs` module.
This test simply initializes logging and then prints out a message with
each of the `log` macros.
Also set the Rust edition to 2018 because the default is the 2015
edition in which using external crates is very clunky.
For the Rust test support in CMake this commit adds support for
cross-compiling the Rust tests.
Rust tests must be built for the same LLVM triple (target platform) as
the rest of the project. In particular this is needed to build both
x64 and x86 packages on a 64bit Windows host.
For Alpine, we observed that the LLVM triple for the host platform tools
may be either:
- x86_64-unknown-linux-musl, or
- x86_64-alpine-linux-musl
To support it either way, we look up the host triple with `rustc -vV`
and use that if the musl libc exists. This is a big hacky and
unfortunately means that we probably can't cross-compile to other
platforms when running on a musl libc host. There are probably
improvements to be made to improve cross compiling support.
The Rust test programs must link with libclamav, libclammspack, and
possibly libclamunrar_iface and libclamunrar plus all of the library
dependencies for those libraries.
To do this, we pass the path of each library in environment variables
when building the libclamav_rust unit test program.
Within `libclamav_rust/build.rs`, we read those environment variables.
If set, we parse each into library path and name components to use
as directives for how to build the unit test program.
See: https://doc.rust-lang.org/cargo/reference/build-scripts.html
Our `build.rs` file ignores the library path environment variables if
thye're not set, which is necessary when building the libclamav_rust
library and when libclamunrar isn't static and for when not linking with
a libiconv external to libc.
Rust test programs are built and executed in subdirectory under:
<target>/<llvm triple>/<config>/deps
where "target" for libclamav_rust tests is set to <build>/unit_tests
For example:
clamav/build/unit_tests/x86_64-pc-windows-msvc/debug/deps/clamav_rust-7e1343f8a2bff1cc.exe
Since this program isn't co-located with the rest of the libraries
we also have to set environment variables so the test program can find and
load the shared libraries:
- Windows: PATH
- macOS: DYLD_LIBRARY_PATH
We already set LD_LIBRARY_PATH when not Windows for similar reasons.
Note: In build.rs, we iterate references to LIB_ENV_LINK & Co because
older Rust versions do implement Iterator for [&str].
Scott Hutton
37e5b573aa