Changes since v0.2.2

Breaking

• The minimum supported rust version (MSRV) was increased to 1.46, due to a cargo issue that recently
  surfaced on CI when using crates.io. Please also note that on MacOS 12 at least Rust 1.54 is required.
• MacOS 10 and 11 are no longer officially supported and untested in CI.
• Increase the minimum required CMake version to 3.15.
• Corrosion internally invokes cargo build. When passing arguments to cargo build, Corrosion
  now uses the CMake VERBATIM option. This may require you to change how you quote
  parameters passed to corrosion (e.g. via corrosion_add_target_rustflags()).
  For example setting a cfg option previously required double escaping the rustflag like this
  "--cfg=something=\\\"value\\\"", but now it should be passed to corrosion without any escapes:
  --cfg=something="value".

Breaking: Removed previously deprecated functionality

• Removed add_crate() function. Use corrosio_import_crate instead.
• Removed cargo_link_libraries() function. Use corrosion_link_libraries() instead.
• Removed experimental CMake option CORROSION_EXPERIMENTAL_PARSER. This option was never included in an official
  release and has been marked as deprecated on the master branch since May 22.
  The corresponding stable option is CORROSION_NATIVE_TOOLING albeit with inverted semantics.
• Previously Corrosion would set the HOST_CC and HOST_CXX environment variables when invoking
  cargo build, if the environment variables CC and CXX outside of CMake where set.
  However this did not work as expected in all cases and sometimes the HOST_CC variable would be set
  to a cross-compiler for unknown reasons. For this reason HOST_CC and HOST_CXX are not set by
  corrosion anymore, but users can still set them manually if required via corrosion_set_env_vars().
• The CARGO_RUST_FLAGS family of cache variables were removed. Corrosion does not internally use them
  anymore.

Potentially breaking

• The working directory when invoking cargo build was changed to the directory of the Manifest
  file. This now allows cargo to pick up .cargo/config.toml files located in the source tree.
  (205)
• Adding a PRE_BUILD custom command on a cargo-build_<target_name> CMake target will no
  longer work as expected. To support executing user defined commands before cargo build is
  invoked users should use the newly added targets cargo-prebuild (before all cargo build invocations)
  or cargo-prebuild_<target_name> as a dependency target.
  Example: add_dependencies(cargo-prebuild code_generator_target)

New features

• Support setting rustflags for only the main target and none of it's dependencies (215).
  A new function corrosion_add_target_local_rustflags(target_name rustc_flag [more_flags ...])
  is added for this purpose.
  This is useful in cases where you only need rustflags on the main-crate, but need to set different
  flags for different targets. Without "local" Rustflags this would require rebuilds of the
  dependencies when switching targets.
• Support explicitly selecting a linker (208).
  The linker can be selected via corrosion_set_linker(target_name linker).
  Please note that this only has an effect for targets, where the final linker invocation is done
  by cargo, i.e. targets where foreign code is linked into rust code and not the other way around.
• Corrosion now respects the CMake OUTPUT_DIRECTORY target properties and copies build artifacts to the expected
  locations (217), if the properties are set.
  This feature requires at least CMake 3.19 and is enabled by default if supported. Please note that the OUTPUT_NAME
  target properties are currently not supported.
  Specifically, the following target properties are now respected:
  • ARCHIVE_OUTPUT_DIRECTORY
  • LIBRARY_OUTPUT_DIRECTORY
  • RUNTIME_OUTPUT_DIRECTORY
  • PDB_OUTPUT_DIRECTORY
• Corrosion now supports packages with potentially multiple binaries (bins) and a library (lib) at the
  same time. The only requirement is that the names of all bins and libs in the whole project must be unique.
  Users can set the names in the Cargo.toml by adding name = <unique_name> in the [[bin]] and [lib] tables.
• FindRust now has improved support for the VERSION option of find_package and will now attempt to find a matching
  toolchain version. Previously it was only checked if the default toolchain matched to required version.
• For rustup managed toolchains a CMake error is issued with a helpful message if the required target for
  the selected toolchain is not installed.

Fixes

• Fix a CMake developer Warning when a Multi-Config Generator and Rust executable targets
  (#213).
• FindRust now respects the QUIET option to find_package() in most cases.

Deprecation notice

• Support for the MSVC Generators with CMake toolchains before 3.20 is deprecated and will be removed in the next
  release (v0.4). All other Multi-config Generators already require CMake 3.20.

Internal Changes

• The CMake Generator written in Rust and CorrosionGenerator.cmake which are responsible for parsing
  cargo metadata output to create corresponding CMake targets for all Rust targets now share most code.
  This greatly simplified the CMake generator written in Rust and makes it much easier maintaining and adding
  new features regardless of how cargo metadata is parsed.