# CMake 3.6 Release Notes

Changes made since CMake 3.5 include the following.

## New Features

### Generators

- The `Ninja` generator learned to produce phony targets of the form `sub/dir/all` to drive the build of a subdirectory. This is equivalent to `cd sub/dir; make all` with Makefile Generators.

- The `Ninja` generator now includes system header files in build dependencies to ensure correct re-builds when system packages are updated.

- The `Visual Studio 14 2015` generator learned to support the Clang/C2 toolsets, e.g. with the `-T v140_clang_3_7` option. This feature is experimental.

### Commands

- The `add_custom_command()` and `add_custom_target()` commands learned how to use the `CROSSCOMPILING_EMULATOR` executable target property.

- The `install()` command learned a new `EXCLUDE_FROM_ALL` option to leave installation rules out of the default installation.

- The `list()` command gained a `FILTER` sub-command to filter list elements by regular expression.

- The `string(TIMESTAMP)` and `file(TIMESTAMP)` commands gained support for the `%s` placeholder. This is the number of seconds since the UNIX Epoch.

### Variables

- A `CMAKE_DEPENDS_IN_PROJECT_ONLY` variable was introduced to tell Makefile Generators to limit dependency scanning only to files in the project source and build trees.

- A new `CMAKE_HOST_SOLARIS` variable was introduced to indicate when CMake is running on an Oracle Solaris host.

- A `CMAKE_<LANG>_STANDARD_INCLUDE_DIRECTORIES` variable was added for use by toolchain files to specify system include directories to be appended to all compiler command lines.

- The `CMAKE_<LANG>_STANDARD_LIBRARIES` variable is now documented. It is intended for use by toolchain files to specify system libraries to be added to all linker command lines.

- A `CMAKE_NINJA_OUTPUT_PATH_PREFIX` variable was introduced to tell the `Ninja` generator to configure the generated `build.ninja` file for use as a `subninja`.

- A `CMAKE_TRY_COMPILE_PLATFORM_VARIABLES` variable was added for use by toolchain files to specify platform-specific variables that must be propagated by the `try_compile()` command into test projects.

- A `CMAKE_TRY_COMPILE_TARGET_TYPE` variable was added to optionally tell the `try_compile()` command to build a static library instead of an executable. This is useful for cross-compiling toolchains that cannot link binaries without custom flags or scripts.

### Properties

- A `DEPLOYMENT_REMOTE_DIRECTORY` target property was introduced to tell the `Visual Studio 9 2008` and `Visual Studio 8 2005` generators to generate the "remote directory" for WinCE project deployment and debugger settings.

- A `<LANG>_CLANG_TIDY` target property and supporting `CMAKE_<LANG>_CLANG_TIDY` variable were introduced to tell the Makefile Generators and the `Ninja` generator to run `clang-tidy` along with the compiler for `C` and `CXX` languages.

- A `TIMEOUT_AFTER_MATCH` test property was introduced to optionally tell CTest to enforce a secondary timeout after matching certain output from a test.

- A `VS_CONFIGURATION_TYPE` target property was introduced to specify a custom project file type for Visual Studio Generators supporting VS 2010 and above.

- A `VS_STARTUP_PROJECT` directory property was introduced to specify for Visual Studio Generators the default startup project for generated solutions (`.sln` files).

### Modules

- The `CMakePushCheckState` module now pushes/pops/resets the variable `CMAKE_EXTRA_INCLUDE_FILES` used in `CheckTypeSize`.

- The `ExternalProject` module leared the `GIT_SHALLOW 1` option to perform a shallow clone of a Git repository.

- The `ExternalProject` module learned to initialize Git submodules recursively and also to initialize new submodules on updates. Use the `GIT_SUBMODULES` option to restrict which submodules are initialized and updated.

- The `ExternalProject` module leared the `DOWNLOAD_NO_EXTRACT 1` argument to skip extracting the file that is downloaded (e.g., for self-extracting shell installers or `.msi` files).

- The `ExternalProject` module now uses `TLS_VERIFY` when fetching from git repositories.

- The `FindBLAS` and `FindLAPACK` modules learned to support OpenBLAS.

- The `FindCUDA` module learned to find the `cublas_device` library.

- The `FindGTest` module `gtest_add_tests` function now causes CMake to automatically re-run when test sources change so that they can be re-scanned.

- The `FindLTTngUST` module was introduced to find the LTTng-UST library.

- The `FindPkgConfig` module learned to optionally create imported targets for the libraries it has found.

- The `FindProtobuf` module learned to provide a `Protobuf_VERSION` variable and check the version number requested in a `find_package()` call.

- The `InstallRequiredSystemLibraries` module learned a new `CMAKE_INSTALL_UCRT_LIBRARIES` option to enable app-local deployment of the Windows Universal CRT libraries with Visual Studio 2015.

### Platforms

- The Clang compiler is now supported on CYGWIN.

- Support was added for the Bruce C Compiler with compiler id `Bruce`.

### CTest

- The `ctest_update()` command now looks at the `CTEST_GIT_INIT_SUBMODULES` variable to determine whether submodules should be updated or not before updating.

- The `ctest_update()` command will now synchronize submodules on an update. Updates which add submodules or change a submodule's URL will now be pulled properly.

### CPack

- The `CPack DEB Generator` learned how to handle `$ORIGIN` in `CMAKE_INSTALL_RPATH` when `CPACK_DEBIAN_PACKAGE_SHLIBDEPS` is used for dependency auto detection.

- The `CPack DEB Generator` learned how to generate `DEBIAN/shlibs` control file when package contains shared libraries.

- The `CPack DEB Generator` learned how to generate `DEBIAN/postinst` and `DEBIAN/postrm` files if the package installs libraries in ldconfig-controlled locations (e.g. `/lib/`, `/usr/lib/`).

- The `CPack DEB Generator` learned how to generate dependencies between Debian packages if multi-component setup is used and `CPACK_COMPONENT_<compName>_DEPENDS` variables are set. For backward compatibility this feature is disabled by default. See `CPACK_DEBIAN_ENABLE_COMPONENT_DEPENDS`.

- The `CPack DEB Generator` learned how to set custom package file names including how to generate properly-named Debian packages:

      <PackageName>_<VersionNumber>-<DebianRevisionNumber>_<DebianArchitecture>.deb

  For backward compatibility this feature is disabled by default. See `CPACK_DEBIAN_FILE_NAME` and `CPACK_DEBIAN_<COMPONENT>_FILE_NAME`.

- The `CPack DEB Generator` learned how to set the package release number (`DebianRevisionNumber` in package file name when used in combination with `DEB-DEFAULT` value set by `CPACK_DEBIAN_FILE_NAME`). See `CPACK_DEBIAN_PACKAGE_RELEASE`.

- The `CPack DEB Generator` learned how to set the package architecture per-component. See `CPACK_DEBIAN_<COMPONENT>_PACKAGE_ARCHITECTURE`.

- The `CPack DragNDrop Generator` learned a new option to skip the `/Applications` symlink. See the `CPACK_DMG_DISABLE_APPLICATIONS_SYMLINK` variable.

- The `CPackIFW` module gained a new `cpack_ifw_update_repository()` command to update a QtIFW-specific repository from a remote repository.

- The `CPack RPM Generator` learned how to set RPM `dist` tag as part of RPM `Release:` tag when enabled (mandatory on some Linux distributions for e.g. on Fedora). See `CPACK_RPM_PACKAGE_RELEASE_DIST`.

- The `CPack RPM Generator` learned how to set default values for owning user/group and file/directory permissions of package content. See `CPACK_RPM_DEFAULT_USER`, `CPACK_RPM_DEFAULT_GROUP`, `CPACK_RPM_DEFAULT_FILE_PERMISSIONS`, `CPACK_RPM_DEFAULT_DIR_PERMISSIONS` and their per component counterparts.

- The `CPack RPM Generator` learned how to set user defined package file names, how to specify that rpmbuild should decide on file name format as well as handling of multiple rpm packages generated by a single user defined spec file. See `CPACK_RPM_FILE_NAME` and `CPACK_RPM_<component>_FILE_NAME`.

- The `CPack RPM Generator` learned how to correctly handle symlinks that are pointing outside generated packages.

### Other

- The `Compile Features` functionality is now aware of features supported by Intel C++ compilers versions 12.1 through 16.0 on UNIX platforms.

## Deprecated and Removed Features

- The `CMakeForceCompiler` module and its macros are now deprecated. See module documentation for an explanation.

- The `find_library()`, `find_path()`, and `find_file()` commands no longer search in installation prefixes derived from the `PATH` environment variable on non-Windows platforms. This behavior was added in CMake 3.3 to support Windows hosts but has proven problematic on UNIX hosts. Users that keep some `<prefix>/bin` directories in the `PATH` just for their tools do not necessarily want any supporting `<prefix>/lib` directories searched. One may set the `CMAKE_PREFIX_PATH` environment variable with a semicolon-separated list of prefixes that are to be searched.

- The `Visual Studio 7 .NET 2003` generator is now deprecated and will be removed in a future version of CMake.

- The `Visual Studio 7` generator (for VS .NET 2002) has been removed. It had been deprecated since CMake 3.3.

- The `Visual Studio 6` generator has been removed. It had been deprecated since CMake 3.3.

## Other Changes

- The precompiled OS X binary provided on `cmake.org` now requires OS X 10.7 or newer.

- On Linux and FreeBSD platforms, when building CMake itself from source and not using a system-provided libcurl, OpenSSL is now used by default if it is found on the system. This enables SSL/TLS support for commands supporting network communication via `https`, such as `file(DOWNLOAD)`, `file(UPLOAD)`, and `ctest_submit()`.

- The `cmake(1)` `--build` command-line tool now rejects multiple `--target` options with an error instead of silently ignoring all but the last one.

- `AUTOMOC` now diagnoses name collisions when multiple source files in different directories use `#include <moc_foo.cpp>` with the same name (because the generated `moc_foo.cpp` files would collide).

- The `FindBISON` module `BISON_TARGET` macro now supports special characters by passing the `VERBATIM` option to internal `add_custom_command()` calls. This may break clients that added escaping manually to work around the bug.

- The `FindFLEX` module `FLEX_TARGET` macro now supports special characters by passing the `VERBATIM` option to internal `add_custom_command()` calls. This may break clients that added escaping manually to work around the bug.

- The `FindProtobuf` module input and output variables were all renamed from `PROTOBUF_` to `Protobuf_` for consistency with other find modules. Input variables of the old case will be honored if provided, and output variables of the old case are always provided.

- The `CPack RPM Generator` now supports upper cased component names in per component CPackRPM specific variables. E.g. component named `foo` now expects component specific variable to be `CPACK_RPM_FOO_PACKAGE_NAME` while before it expected `CPACK_RPM_foo_PACKAGE_NAME`. Upper cased component name part in variables is compatible with convention used for other CPack variables. For back compatibility old format of variables is still valid and preferred if both versions of variable are set, but the preferred future use is upper cased component names in variables. New variables that will be added to CPackRPM in later versions will only support upper cased component variable format.

- The CPack NSIS generator's configuration file template was fixed to quote the path to the uninstaller tool used by the `CPACK_NSIS_ENABLE_UNINSTALL_BEFORE_INSTALL` option. This avoids depending on an insecure Windows feature to run an uninstaller tool with a space in the path.