Developers guide

Checklist for adding / removing a library

1. Add a WITH_LIBRARYNAME CMake option to:
   • root CMakeLists.txt (if it has some inter-library dependencies, update the others / convert them to cmake_dependent_option(), adding NOT WITH_LIBRARYNAME to their condition — note the conditions are ANDed so they need to be specified in reverse)
   • the list in doc/building.dox (and similar files in other repos)
2. Update FindCorrade.cmake (or similar in other repos):
   • mention the new lib in the list of components in the docs
   • if it has some inter-library dependencies, add a corresponding _CORRADE_${_COMPONENT}_DEPENDENCIES entry
   • add its name to the _CORRADE_LIBRARY_COMPONENTS regex
   • add a new elseif(_component STREQUAL LibraryName) section with special setup of includes or dependencies or explicitly say # No special setup for LibraryName library
3. Add the library to the list in doc/corrade-cmake.dox
4. Add a conditional add_subdirectory() to src/Corrade/CMakeLists.txt
5. Create a new src/Corrade/LibraryName/CMakeLists.txt, copy over up-to-date license header from other CMake files, add your name to it and populate it:
   • add source files to CorradeLibraryName_SRCS variable
   • add installable headers to CorradeLibraryName_HEADERS variable
   • add private headers to CorradeLibraryName_PRIVATE_HEADERS variable (if any)
   • if the test needs some extra setup (such as e.g. CORRADE_NO_ASSERT enabled for particular files), create a new CorradeLibraryNameObjects OBJECT library with files that can be compiled the same way in both cases to speed up compilation
   • verify that the add_library() command references all input files (needed so QtCreator lists all project files properly)
   • verify that debug postfix is set (set_target_properties(CorradeLibraryName PROPERTIES DEBUG_POSTFIX "-d"))
   • verify that folder is set for all libraries and OBJECT libraries to avoid cluttering project tree view in IDEs (set_target_properties(CorradeLibraryName PROPERTIES FOLDER "Corrade/LibraryName"))
   • verify that target installation is done in proper places (separate RUNTIME / LIBRARY / ARCHIVE destinations)
   • verify that set_target_properties(CorradeLibraryName PROPERTIES VERSION ${CORRADE_LIBRARY_VERSION} SOVERSION ${CORRADE_LIBRARY_SOVERSION}) is done in case BUILD_STATIC is not set
   • verify that set_target_properties(CorradeLibraryName PROPERTIES POSITION_INDEPENDENT_CODE ON) is done in case BUILD_STATIC_PIC is set
   • verify that add_library(Corrade::LibraryName ALIAS CorradeLibraryName) (or equivalent) is added to make the library visible for CMake subprojects
6. Create a new src/Corrade/LibraryName/Test/ directory:
   • add a CMakeLists.txt with pre-populated license header, add your name to it
   • conditionally add_subdirectory() it if BUILD_TESTS is enabled
7. Create a new src/Corrade/LibraryName/LibraryName.h header for forward declarations (if needed), add a file-level doc block with Forward declarations for the @ref Corrade::LibraryName namespace as brief docs
8. Create a new src/Corrade/LibraryName/visibility.h header with CORRADE_LIBRARYNAME_EXPORT and CORRADE_LIBRARYNAME_LOCAL macros by copypasting it from another library:
   • adapt #ifdef CorradeLibraryName_EXPORTS so it matches CMake target name
   • if the library is combined from an OBJECT library, add its name to the above #ifdef as well (and then explicitly add target_compile_definitions(ĆorradeLibraryNameObjects PRIVATE "CorradeLibraryNameObjects_EXPORTS") to CMakeLists.txt in case BUILD_STATIC is not set)
9. Mention the directory and namespace in doc/namespaces.dox, basically copy-pasting the following from existing documentation:
   • directory-level doc block referencing the namespace
   • namespace-level doc block mentioning the WITH_LIBRARYNAME option, dependencies (if any) and a code snippet showing how to use it with CMake
10. Code and test the rest of the library, see Checklist for adding / removing a new source / header file and Checklist for adding / removing a symbol for more information
11. Add the WITH_LIBRARYNAME option to all files in package/ directory, explicitly saying either ON or OFF based on platform support:
    • all package/archlinux/PKGBUILD* files (and the AUR package(s))
    • the package/debian/rules file (watch out, tabs!)
    • the package/gentoo/ *.ebuild file
    • the package/homebrew/ *.rb file (watch out, Ruby!)
    • all package/ci/appveyor-*.bat files (^ is a line continuation)
    • all package/ci/travis-*.sh files (\ is a line continuation)
12. If the library has dependencies:
    • make sure they are mentioned in the library documentation
    • make sure they are mentioned in building and CMake docs
    • make sure they are mentioned in CREDITS.md
    • make sure AppVeyor and Travis downloads them (based on platform support)
13. Mention the library in doc/corrade-changelog.dox
14. Build documentation:
    • run dox2html5.py on Doxyfile-mcss and verify there are no new warnings
    • eyeball the namespace and directory docs, fix suspicious things, look also in the building and cmake docs
15. Build a coverage build (package/archlinux/PKGBUILD-coverage), or abuse the CI for that later
16. Push to a temporary branch (e.g., next)
17. Iterate until the CIs are green and the code coverage is good enough
18. Merge to master

In order to remove a library, be sure to touch all places mentioned above, only in inverse — but usually deprecate first.

Checklist for adding / removing a plugin

Similarly to Checklist for adding / removing a library except points 2 and 5, with:

1. Update FindCorrade.cmake (replaces point 2 in Checklist for adding / removing a library):
   • mention the new plugin in the list of components in the docs
   • add its name to the _CORRADE_PLUGIN_COMPONENTS regex
   • add a new elseif(_component STREQUAL PluginName) section with special setup of includes or dependencies or explicitly say # PluginName has no dependencies
2. Create PluginName.conf and list all plugin dependencies (if any). The file has to be present even if empty.
3. Create pluginRegistration.cpp by copypasting it from another plugin and adapting plugin name and plugin interface string. It's needed to be in a separate file that gets compiled only to the plugin library, not to the test library.
4. Create configure.h.cmake for plugin-specific information about whether the library was built as static or not
5. Create a new src/CorradePlugins/PluginName/CMakeLists.txt, copy over up-to-date license header from other CMake files and populate it (replaces point 5 in Checklist for adding / removing a library):
   • add source files to PluginName_SRCS variable
   • add installable headers to PluginName_HEADERS variable
   • add private headers to PluginName_PRIVATE_HEADERS variable (if any)
   • create a PluginNameObjects library that contains all files that are common for the plugin library and test library (usually everything except pluginRegistration.cpp), add a target_compile_definitions(PluginNameObjects PRIVATE "PluginNameObjects_EXPORTS") for it
   • use add_plugin() command (which is aliased to either corrade_add_plugin() or corrade_add_static_plugin()) to create the PluginName library, use ${CORRADE_PLUGINS_*_DEBUG_BINARY_INSTALL_DIR} / ${CORRADE_PLUGINS_*_RELEASE_BINARY_INSTALL_DIR} and ${CORRADE_PLUGINS_*_DEBUG_LIBRARY_INSTALL_DIR} / ${CORRADE_PLUGINS_*_RELEASE_LIBRARY_INSTALL_DIR} variables that correspond to given plugin interface
   • verify that both add_library() and add_plugin() commands reference all input files (needed so QtCreator lists all project files properly)
   • verify that folder is set for the OBJECT library and the test library to avoid cluttering project tree view in IDEs (set_target_properties(PluginNameObjects PROPERTIES FOLDER "CorradePlugins/PluginName")) — for the plugin library it's done automatically inside add_plugin()
   • verify that set_target_properties(PluginName PROPERTIES POSITION_INDEPENDENT_CODE ON) is done in case BUILD_STATIC_PIC is set
   • verify that add_library(Corrade::PluginName ALIAS PluginName) (or equivalent) is added to make the library visible for CMake subprojects
6. If there is more than one interface header (other than just PluginName.h being installed), add a new visibility.h header. Otherwise put the visibility macros directly in PluginName.h.

In order to remove a plugin, be sure to touch all places mentioned above, only in inverse — but usually deprecate first.

Checklist for adding / removing a plugin interface

In order to remove a plugin interface, be sure to touch all places mentioned above, only in inverse — but usually deprecate first.

Checklist for adding / removing a tool

In order to remove a tool, be sure to touch all places mentioned above, only in inverse — but usually deprecate first.

Checklist for adding / removing an example

1. Add a new src/examples/name directory, copy up-to-date UNLICENSE headers from other files in the repo
2. Verify that src/examples/name/CMakeLists.txt contains cmake_minimum_required(), project() and all cmake_policy() commands so it can be used as a top-level project level
3. Add a new doc/name.dox page with @brief, @m_footernavigation and @page name equivalent to filename, describe what the example is doing
4. Add a new examplename-source section with:
   • link to GitHub
   • referencing all textual example sources as - @ref example-name/file.ext "file.ext"
   • breadcrumb and navigation setup for all example sources as @example example-name/file.ext @m_examplenavigation{examples-example-name,example-name/} @m_footernavigation
5. Update doc/corrade-example-index.dox and list the example there
6. Mention the example in doc/corrade-changelog.dox
7. Push to a temporary branch (e.g., next or ports-next)
8. Iterate until the CIs are green
9. Merge to master / ports

In order to remove an example, be sure to touch all places mentioned above, but in inverse.

Checklist for adding / removing a new source / header file

1. Copy over a up-to-date license header (note that example code uses UNLICENSE instead of MIT) and add your name + year to it, if not already there
2. Add a @file-level documentation block, with @brief listing all classes, functions, typedefs, enums, macros etc. that are in the file
3. Add the file to corresponding *_SRCS, *_HEADERS, *_PRIVATE_HEADERS list in CMakeLists.txt
4. If applicable, add a new test class file in the Test/ directory
   • name it FileNameTest.cpp, put a class named FileNameTest inside, wrapped in a Test subnamespace of the original file namespace
   • use corrade_add_test() to add it to tests
   • if some tests need GL context, add a separate test with GLTest suffix, wrapping the corresponding corrade_add_test() in if(BUILD_GL_TESTS)
5. Populate the file, see Checklist for adding / removing a symbol and Coding style for more information.
6. Mention the new functionality in doc/corrade-changelog.dox
7. Build documentation:
   • run dox2html5.py on Doxyfile-mcss and verify there are no new warnings
   • eyeball the relevant docs and fix suspicious things
8. Build a coverage build (package/archlinux/PKGBUILD-coverage), or abuse the CI for that later
9. Push to a temporary branch (e.g., next)
10. Iterate until the CIs are green and the code coverage is good enough
11. Merge to master

In order to remove a file, be sure to touch all places mentioned above, only in inverse — but usually deprecate first.

Checklist for adding / removing a symbol

1. If the symbol is standalone (i.e., not member of a class), list it in the @file-level @brief docs
2. Document it
3. Add a test for it to corresponding file, verify the test gets actually run
4. Mention the new functionality in doc/changelog.dox (and similar files in other repos)
5. Build documentation:
   • run dox2html5.py on Doxyfile-mcss and verify there are no new warnings
   • eyeball the relevant docs and fix suspicious things
6. Build a coverage build (package/archlinux/PKGBUILD-coverage), or abuse the CI for that later
7. Push to a temporary branch (e.g., next)
8. Iterate until the CIs are green and the code coverage is good enough
9. Merge to master

In order to remove a symbol, be sure to touch all places mentioned above, only in inverse — but usually deprecate first.

Checklist for adding a new CMake documentation page

1. Add a doc/pagename.dox file, copy up-to-date license header and add your name + year to it, if not already there
2. If the page is top-level, list it in doc/00-page-order.dox to ensure it gets listed at a proper place
3. If the page is not top-level, list it using @subpage in its parent page and add @m_footernavigation for automatic linking to parent and prev/next pages
4. Add a @brief documentation, if applicable
5. Populate it, see Coding style for more information
6. Mention the new page in doc/changelog.dox (and similar files in other repos)
7. Build documentation:
   • run dox2html5.py on Doxyfile-mcss and verify there are no new warnings
   • eyeball the relevant docs and fix suspicious things
8. Push to master

Checklist for deprecating a feature

1. If the feature is publicly exposed, think about the best way of deprecation that preserves source compatibility:
   • Add a compatibility typedef / using for a renamed symbol, marking it with CORRADE_DEPRECATED() / CORRADE_DEPRECATED_ALIAS()
   • Add a compatibility header for a renamed include, including the original file from it and marking it with CORRADE_DEPRECATED_FILE()
   • Add a compatibility inline function for a function that got renamed or its arguments changed, mark it with CORRADE_DEPRECATED()
   • Add a compatibility enum value for a value that got renamed or deleted, mark it with CORRADE_DEPRECATED_ENUM()
   • Don't ever change semantics of function arguments without changing the function signature. That would silently break with no possibility to let the user know.
   • Function return type changes are hard. One possibility is working around that by returning a wrapper type that's implicitly convertible to both the old and new type, another is introducing a differently named function instead. The last resort is breaking the API without preserving backwards compatibility — but that makes people angry, so avoid that if possible.
2. Add just a @brief @copybrief from the replacement functionality together with a @deprecated line to the deprecated feature
3. Reference the replacement functionality in both the deprecation macro and in the @deprecated line to make porting easier
4. Ensure the deprecated symbol is wrapped in #ifndef CORRADE_BUILD_DEPRECATED,
5. Ensure deprecated files #error in case they get used in non-deprecated build, ensure they are not installed in non-deprecated builds
6. Build all tests and dependent projects and verify that:
   • using the old functionality still compiles and works as intended
   • deprecation warnings are emitted in proper places
7. Upon verifying the above, start updating dependent code
8. Mention the deprecated API in the deprecation section of doc/corrade-changelog.dox
9. Build documentation:
   • run dox2html5.py on Doxyfile-mcss and verify there are no new warnings
   • eyeball the relevant docs and fix suspicious things
10. Push to a temporary branch (e.g., next)
11. Iterate until the CIs are green
12. Merge to master
13. If possible, trigger builds of dependent projects (where they are still using the old API) and verify they are still green (and red in non-deprecated build)
14. Update dependent projects

Checklist for removing a feature

1. Check that it was in deprecated state for more than a year with at least one release in between. Check that no important clients depend on it anymore. If not, wait a bit more.
2. Remove relevant blocks wrapped in #ifndef CORRADE_BUILD_DEPRECATED, remove relevant deprecated files and update CMakeLists.txt
3. Mention the removed API in the compatibility section of doc/changelog.dox (or similar files in other repos)
4. Build documentation:
   • run dox2html5.py on Doxyfile-mcss and verify there are no new warnings — sometimes it happens that a deprecated API is still being referenced
5. Push to a temporary branch (e.g., next)
6. Iterate until the CIs are green
7. Merge to master
8. If possible, trigger builds of dependent projects and verify they are still green (or wait for the scheduled builds)

Checklist for adding, removing or updating a dependency

1. Verify that there are no important clients stuck on the old version with no easy way to upgrade
2. In case of CMake:
   • it's usually possible to jump more than one version, check what's the version on the oldest supported system
   • bump all cmake_minimum_required() in all repos
   • remove cmake_policy() calls that are not needed anymore
   • remove old workarounds, check changelogs for functionality that can be used now
   • update building docs to say what version is required now
   • add an entry to the dependencies section in doc/changelog.dox
   • update package/ci/travis.yml to download a newer version, possibly removing 32-bit compat libraries
3. In case of a compiler:
   • remove everything related to CORRADE_GCCXY_COMPATIBILITY of the old version, if applicable
   • update building docs to say what version is required now
   • add an entry to the dependencies section in doc/changelog.dox
   • update files in package/ci/ to use a newer version
4. In case given dependency is external:
   • Create a dedicated Find*.cmake module and does not have a builtin one in CMake
   • update packages in package/ to depend on the new library
   • update files in package/ci/ to install it
5. In case given dependency is single-file:
   • verify it's reasonably small (<50kB is okay, nlohmann/json is a prime example of not okay)
   • add it to src/external/ without any modifications except for trailing whitespace cleanup
   • add it in a separate Git commit, mentioning its version (or Git hash) for easier upgrades later
6. Update CREDITS.md of affected repo to mention the added/removed dependency, its homepage and its license

In order to remove a dependency, be sure to touch all places mentioned above, only in inverse.

Checklist for adding or removing a port

1. Add a new TARGET_* variable:
   • to root CMakeLists.txt, which either gets enabled automatically based on system introspection or is exposed through a option() command
   • to the list of variables extracted out of configure.h in modules/FindCorrade.cmake
2. Add a CORRADE_TARGET_* variable:
   • set it in root CMakeLists.txt in case TARGET_* is enabled
   • add it as a #cmakedefine macro to src/Corrade/configure.h.cmake
   • add documentation for it to src/Corrade/Corrade.h
   • mention it in modules/FindCorrade.cmake docs
   • mention it in doc/corrade-cmake.dox and doc/building-corrade.dox
3. Add a new Travis / AppVeyor matrix build for this port (or update existing)
4. Add a new PKGBUILD-* file in package/archlinux for testing (or update existing)
5. Enable or disable functionality using if(CORRADE_TARGET_*) in CMake and #ifdef CORRADE_TARGET_* in C++
6. Mention the new stuff in doc/corrade-changelog.dox
7. Push to a temporary branch (e.g., next)
8. Iterate until the CIs are green
9. Merge to master

In order to remove a port, be sure to touch all places mentioned above, only in inverse.

Checklist for updating copyright year

1. Verify there are no uncommitted changes in any repos, as that would significantly complicate reverting a potential fuck-up
2. Use msrp to batch replace copyright info in all files, replacing existing Copyright © ... with Copyright © ..., 20XZ in the root directory of every project, so nothing gets left out
3. Examples use partially MIT (mainly in docs) and partially UNLICENSE, replace ... — with ..., 20XZ — there as well
4. Copy all Find*.cmake modules to dependent projects to update the copyright year in these as well
5. Update package/debian/copyright to say the new year as well
6. Use git diff to verify the change went well and the new year is specified exactly once everywhere
7. Do a local verification build, push to master

Checklist for uploading documentation

1. (Optionally) remove build/doc-public to get rid of stale files
2. Verify there are no untracked files, modifications or branches different than master checked out that could mess up the docs
3. Run dox2html5.py on Doxyfile-public, look for suspicious warnings
4. Upload contents of build/doc-public/html/ to doc/corrade-new/ and remove doc/corrade-old/ if any
5. Once the upload is finished, rename doc/corrade/ to doc/corrade-old/ and doc/corrade-new/ to doc/corrade/
6. Quickly check that the docs still look as they should, if not, revert the backup and try again

Checklist for merging a PR

1. After the public round of review, pull the changes locally to a temporary branch (i.e., next)
2. Verify a coverage build, verify that there are no compiler warnings
3. Go over and fix issues that slipped through cracks in the public review
4. Verify the contributor is mentioned in all relevant license headers, add if necessary
5. Add the contributor to CREDITS.md, if not already there
6. Update doc/corrade-changelog.dox, if not already done
7. Build documentation:
   • run dox2html5.py on Doxyfile-mcss and verify there are no new warnings
   • eyeball the relevant docs and fix suspicious things
8. Push to a temporary branch (e.g., next)
9. Iterate until the CIs are green
10. Merge to master, put a "thank you" comment to the PR, explaining additional changes if necessary

Checklist for making a release

1. Open a new 20XY.ac milestone
2. Verify that there are no blocking issues in the current (20XY.ab) milestone, either fix them or move to the next milestone
3. Verify that all CIs are green
4. Go through doc/corrade-changelog.dox and update it, in case it doesn't contain all changes (use gitk to check when it was last updated)
5. Go through fixed issues and merged PRs and add either a changelog mention added (and add a mention to the changelog), scrapped or no action needed label to wrap them up
6. Update changelog for the next release:
   • change section names for the latest release from latest to 20XY-ab
   • change the title from Changes since 20XY.aa to 20XY.ab
   • add a paragraph stating date of release and referencing the to-be-added tag on GitHub
7. Bump CORRADE_LIBRARY_VERSION and CORRADE_LIBRARY_SOVERSION in all projects, if needed — ensure consistency with Magnum releases
8. Rebuild all projects with the new shared library version numbers, verify all tools and examples still behave properly
9. Build and upload public docs (see Checklist for uploading documentation), verify that there are no new warnings and the changelog looks correct
10. Push all new changes to a temporary branch (e.g., next)
11. Wait for the CIs to get green
12. Tag a new version using git tag -a v20XY.ab, say just Version 20XY.ab as a message
13. Push the tag, verify that the CIs are still green
14. Add content to the corresponding Magnum release announcement
15. Update versions of ArchLinux AUR packages:
    • run makepkg in package/archlinux/corrade-git, verify it builds and says correct version, ideally with r0 at the ennd
    • copy the updated PKGBUILD to the AUR package repo, run makepkg --printsrcinfo > .SRCINFO there
    • commit the updated PKGBUILD and .SRCINFO, push
    • after pushing all, verify that the version is updated in the AUR web interface as well
16. Update Debian package changelog in package/debian/changelog, copypasting the last entry, updating it and using the Git tag date+time for it (note that the date format is slightly different)
17. Update Homebrew package versions
18. Ask someone to update Vcpkg packages
19. Close the 20XY.ab GitHub milestone
20. Add link to the release notes to the tag on GitHub