v0.4 beta 1 - Please test and report issues

[jschwe]

0.4.0-beta1 (2023-05-10)

Please test and provide feedback for issues you encounter. We are especially interested in receiving feedback for the things in the experimental section of the release notes, especially the cbindgen and cxxbridge integration.

Changes compared to v0.3.5:

Breaking Changes

• The Visual Studio Generators now require at least CMake 3.20.
  This was previously announced in the 0.3.0 release notes and is the same
  requirement as for the other Multi-Config Generators.
• The previously deprecated function corrosion_set_linker_language()
  will now raise an error when called and may be removed without further
  notice in future stable releases. Use corrosion_set_linker() instead.
• Improved the FindRust target triple detection, which may cause different behavior in some cases.
  The detection does not require an enabled language anymore and will always fall back
  to the default host target triple. A warning is issued if target triple detection failed.

Potentially Breaking Changes

• Corrosion now sets the IMPORTED_NO_SONAME property for shared rust libraries, since by
  default they won't have an soname field.
  If you add a rustflag like -Clink-arg=-Wl,-soname,libmycrate.so in your project,
  you should set this property to false on the shared rust library.
• Corrosion now uses a mechanism to determine which native libraries need to be linked with
  Rust staticlib targets into C/C++ targets. The previous mechanism contained a hardcoded list.
  The new mechanism asks rustc which libraries are needed at minimum for a given
  target triple (with std support). This should not be a breaking change, but if you
  do encounter a new linking issue when upgrading with staticlib targets, please open an
  issue.

New features

• corrosion_import_crate() has two new options LOCKED and FROZEN which pass the
  --locked and --frozen flags to all invocations of cargo.
• FindRust now provides cache variables containing information on the default host
  target triple:
  • Rust_CARGO_HOST_ARCH
  • Rust_CARGO_HOST_VENDOR
  • Rust_CARGO_HOST_OS
  • Rust_CARGO_HOST_ENV

Other changes

• When installing Corrosion with CMake >= 3.19, the legacy Generator tool is
  no longer built and installed by default.
• Corrosion now issues a warning when setting the linker or setting linker
  options for a Rust static library.
• Corrosion no longer enables the C language when CMake is in crosscompiling mode and
  no languages where previously enabled. This is not considered a breaking change.
• corrosion_import_crate() now warns about unexpected arguments.

Fixes

• Fix building when the dev profile is explicitly set by the user.

Experimental status (may be changed or removed before a stable release)

• Experimental cxxbridge and cbindgen integration.
• Add a helper function to parse the package version from a Cargo.toml file
• Expose rustup toolchains discovered by FindRust in the following cache variables
  which contain a list.
  • Rust_RUSTUP_TOOLCHAINS: List of toolchains names
  • Rust_RUSTUP_TOOLCHAINS_VERSION: List of rustc version of the toolchains
  • Rust_RUSTUP_TOOLCHAINS_RUSTC_PATH: List of the path to rustc
  • Rust_RUSTUP_TOOLCHAINS_CARGO_PATH: List of the path to cargo. Entries may be NOTFOUND if cargo
    is not available for that toolchain.
• Add target properties INTERFACE_CORROSION_RUSTC and INTERFACE_CORROSION_CARGO, which may
  be set to paths to rustc and cargo respectively to override the toolchain for a specific
  target.

---

This discussion was created from the release v0.4 beta 1 - Please test and report issues.

[ogoffart]

At least, our CI passed with v0.4 beta: slint-ui/slint#2731 🎉

[OlivierLDff]

Our ci using cxxbridge function works like a charm on Ubuntu (ninja) and windows (msvc)

[jschwe]

@OlivierLDff How is your general experience with the cxxbridge function? We don't use it at work (no C++ in our codebase), so the testing on my side is quite limited. Currently the function is documented as experimental and I'm interested in hearing real word usage experiences before commiting to stabilizing the current API of the function.

[OlivierLDff]

So we are using it to add some rust to our C++ codebase.

Usage is pretty simple, no special hack or advance usage (which is nice, for once)

We have 2 crates in a workspace called kapta-rs and another kapta-cxx that do the binding of rust code to C++ using cxx library.

set(KAPTA_TARGET
    "kapta_rs"
    CACHE STRING "Target Name"
)

if(KAPTA_BUILD_SHARED)
  set(KAPTA_CXX_CRATE_TYPE cdylib)
else()
  set(KAPTA_CXX_CRATE_TYPE staticlib)
endif()

corrosion_import_crate(
  MANIFEST_PATH src/kapta-cxx/Cargo.toml
  IMPORTED_CRATES KAPTA_CXX_CRATE
  CRATE_TYPES ${KAPTA_CXX_CRATE_TYPE}
  CRATES kapta-cxx
)

corrosion_add_cxxbridge(
  ${KAPTA_TARGET}
  CRATE ${KAPTA_CXX_CRATE}
  FILES lib.rs
)

I import corrosion using CPM.cmake

# Heuristic to detect if corrosion is already imported
if(COMMAND corrosion_import_crate)
  return()
endif()

include(${CMAKE_CURRENT_LIST_DIR}/CPM.cmake)

CPMAddPackage(
  NAME corrosion
  GIT_REPOSITORY "https://github.com/Naostage/corrosion"
  GIT_TAG "4c36abff079364d6ebdf51526fc3457c216a0545"
)

[temeddix]

We're getting errors. We have CMake 3.25 installed, but the error tells us that we need to have CMake 3.20 or higher.
cunarist/rinf#25 (comment)

[jschwe]

I already replied in the linked issue, but for completeness sake: this is a user issue, where a vendored CMake version provided by the IDE is used, which is less recent than the installed CMake version. Maybe we could print the actual CMake version in the error message, to give the user a better hint at which CMake version specifically is being used.

[temeddix]

Yeah it is, I think it would be great to add that info in the error log

[OlivierLDff]

Could be interesting to also log full path of used cmake executable? So its even more obvious to the user when non system cmake is used

[jschwe]

Thanks - added in #393