# CMake 3.27 Release Notes

Changes made since CMake 3.26 include the following.

## New Features

### Debugger

- `cmake(1)` now supports interactive debugging of the CMake language. See the `--debugger` option.

### Presets

- `cmake-presets(7)` files now support schema version `7`.

- `cmake-presets(7)` now supports `$penv{}` macro expansion in `include` fields.

### Generators

- The Makefile and Ninja generators now support using the `--dependency-file` linker flag, added by GNU Binutils 2.35 and LLVM's LLD 12.0.0, so that files read by the linker will cause a relink if they change (typically modified timestamps). See the `CMAKE_LINK_DEPENDS_USE_LINKER` variable.

- The Visual Studio Generators for VS 14 (2015) and above learned to select the Windows SDK version explicitly using a `version=` field in the `CMAKE_GENERATOR_PLATFORM` variable. See Visual Studio Platform Selection.

### Languages

- The `CXX` language now treats source file extensions `.ccm`, `.cxxm`, and `.c++m` as C++.

### File-Based API

- The `cmake-file-api(7)` "codemodel" version 2 `version` field has been updated to 2.6.

- The `cmake-file-api(7)` "codemodel" version 2 "target" object gained a new "frameworks" field in the "compileGroups" objects.

### Platforms

- Apple text-based stubs (i.e. `.tbd` files) may now be created for shared libraries on macOS. See the `ENABLE_EXPORTS` property.

### Commands

- The `add_custom_command()` command gained a new `DEPENDS_EXPLICIT_ONLY` option to tell the Ninja Generators not to add any dependencies implied by the target to which it is attached. The `CMAKE_ADD_CUSTOM_COMMAND_DEPENDS_EXPLICIT_ONLY` variable was added to enable `DEPENDS_EXPLICIT_ONLY` on all calls to `add_custom_command()` command.

- The `cmake_file_api()` command was added for projects to add `CMake file API` queries for the current CMake run.

- The `find_package()` command now searches prefixes specified by upper-case `<PACKAGENAME>_ROOT` CMake variables and upper-case `<PACKAGENAME>_ROOT` environment variables. See policy `CMP0144`.

- The `install(CODE)` and `install(SCRIPT)` commands now support the `$<INSTALL_PREFIX>` generator expression.

### Variables

- The `CMAKE_DLL_NAME_WITH_SOVERSION` variable and associated `DLL_NAME_WITH_SOVERSION` target property were added to optionally append the `SOVERSION` to the filename of the `.dll` part of a shared library on Windows.

- Variables `CMAKE_VS_DEBUGGER_COMMAND`, `CMAKE_VS_DEBUGGER_COMMAND_ARGUMENTS`, `CMAKE_VS_DEBUGGER_ENVIRONMENT`, and `CMAKE_VS_DEBUGGER_WORKING_DIRECTORY` were added to initialize corresponding target properties.

- The `CMAKE_VS_WINDOWS_TARGET_PLATFORM_MIN_VERSION` variable was added to initialize the `VS_WINDOWS_TARGET_PLATFORM_MIN_VERSION` target property on all targets when they are created.

### Properties

- A `CUDA_CUBIN_COMPILATION` target property was added to Object Libraries to support compiling to `.cubin` files instead of host object files. Currently only supported with NVIDIA.

- A `CUDA_FATBIN_COMPILATION` target property was added to Object Libraries to support compiling to `.fatbin` files instead of host object files. Currently only supported with NVIDIA.

- A `CUDA_OPTIX_COMPILATION` target property was added to Object Libraries to support compiling to `.optixir` files instead of host object files. Currently only supported with NVIDIA.

- The `<LANG>_CLANG_TIDY`, `<LANG>_CPPCHECK`, `<LANG>_CPPLINT`, and `<LANG>_INCLUDE_WHAT_YOU_USE`, target properties now support `generator expressions`.

- The `<LANG>_LINKER_LAUNCHER` target property now supports `generator expressions`.

- The `SKIP_LINTING` source file property was added to suppress target-wide code checks on specific sources.

### Modules

- The `FindCUDAToolkit` module now provides an imported target for `cudla`, and imported targets for CUPTI's `nvperf` and `pcsampling` components.

- The `FindDoxygen` module's `doxygen_add_docs()` command gained a `CONFIG_FILE` option to specify a custom doxygen configuration file.

- The `FindOpenGL` module gained support for components `GLES2` and `GLES3`.

- The `FindwxWidgets` module now provides an imported target.

### Generator Expressions

- The `COMPILE_ONLY` generator expression was added to specify compilation usage requirements without any linking requirements.

- `$<LIST:...>` generator expressions were added for query, transformation, and ordering operations on lists.

- `$<PATH:...>` generator expressions for decomposition and transformation operations learned to process lists of paths element-wise.

- The `TARGET_IMPORT_FILE`, `TARGET_IMPORT_FILE_BASE_NAME`, `TARGET_IMPORT_FILE_PREFIX`, `TARGET_IMPORT_FILE_SUFFIX`, `TARGET_IMPORT_FILE_NAME`, and `TARGET_IMPORT_FILE_DIR` generator expressions were added. These expand to details about the linker import file for a target.

- The `TARGET_RUNTIME_DLL_DIRS` generator expression was added. It expands to a list of the directories containing DLLs in `TARGET_RUNTIME_DLLS`.

### Autogen

- The `CMAKE_AUTOMOC_EXECUTABLE`, `CMAKE_AUTORCC_EXECUTABLE`, and `CMAKE_AUTOUIC_EXECUTABLE` variables were added to initialize the corresponding target properties as targets are created.

- The `AUTOGEN_USE_SYSTEM_INCLUDE` target property and corresponding `CMAKE_AUTOGEN_USE_SYSTEM_INCLUDE` variable were added to explicitly control whether autogen headers are considered system headers.

- The `INTERFACE_AUTOMOC_MACRO_NAMES` target property was added to specify macro names for `moc` as a transitive usage requirement.

### CTest

- The `TIMEOUT_SIGNAL_NAME` and `TIMEOUT_SIGNAL_GRACE_PERIOD` test properties were added to specify a POSIX signal to send to a test process when its timeout is reached.

### CPack

- The `CPack Inno Setup Generator` was added to package using Inno Setup.

## Deprecated and Removed Features

- Compatibility with versions of CMake older than 3.5 is now deprecated and will be removed from a future version. Calls to `cmake_minimum_required()` or `cmake_policy()` that set the policy version to an older value now issue a deprecation diagnostic.

- The Extra Generators have been deprecated. IDEs may use the `cmake-file-api(7)` to view CMake-generated project build trees.

- The `FindCUDA` module, which has been deprecated since CMake 3.10, has been removed by policy `CMP0146`. Port projects to CMake's first-class `CUDA` language support.

- The `FindPythonInterp` and `FindPythonLibs` modules, which have been deprecated since CMake 3.12, have been removed by policy `CMP0148`. Port projects to `FindPython3`, `FindPython2`, or `FindPython`.

- The `Dart` and `FindDart` modules have been deprecated via policy `CMP0145`. Port projects to the `CTest` module.

- The `Visual Studio 9 2008` generator is now deprecated and will be removed in a future version of CMake.

## Other Changes

- `cmake --build $dir --verbose` will now print the working directory and command line used to perform the build.

- The `ExternalProject` and `FetchContent` modules now resolve relative `GIT_REPOSITORY` paths as relative to the parent project's remote, not as a relative local file system path. See `CMP0150`.

- The `ExternalProject` `configure` step no longer re-runs on every build when the `UPDATE_DISCONNECTED` option is enabled. It will only re-run if details of the `download`, `update`, or `patch` step change.

- The `ExternalProject` `update` and `patch` steps now always re-run if any of their details change, even if the `UPDATE_DISCONNECTED` option is enabled. If using the `GIT` download method, and the `GIT_TAG` is changed to a commit that is not already known locally, an error is now issued instead of silently using the previous `GIT_TAG`.

- The `FindPython`, `FindPython2` and `FindPython3` modules now support the Windows ARM64 platform.

- The `file(GET_RUNTIME_DEPENDENCIES)` command now case-preserves DLL names reported on Windows. They are still converted to lowercase for filter matching.

- The `SYSTEM` target property is now honored for Apple Frameworks.

- Visual Studio Generators, for VS 15.8 (2017) and newer, now build custom commands in parallel. See policy `CMP0147`.

- Visual Studio Generators for VS 14 (2015) and above now prefer to select the latest Windows SDK version. See policy `CMP0149`.

## Updates

Changes made since CMake 3.27.0 include the following.

### 3.27.1

- This version made no changes to documented features or interfaces. Some implementation updates were made to support ecosystem changes and/or fix regressions.

### 3.27.2

- Visual Studio Generators for VS 14 (2015) and above now prefer to select the latest Windows SDK, as documented by policy `CMP0149`, when targeting any version of Windows. In CMake 3.27.[0-1] the preference was limited to targeting Windows 10 and above.

- Visual Studio Generators for VS 14 (2015) and above now support using `version=8.1` in the `CMAKE_GENERATOR_PLATFORM` variable to select the Windows 8.1 SDK. In CMake 3.27.[0-1] the `version=` field was limited to selecting Windows 10 SDKs.

### 3.27.3, 3.27.4, 3.27.5, 3.27.6

- These versions made no changes to documented features or interfaces. Some implementation updates were made to support ecosystem changes and/or fix regressions.